Document and Entity Information (USD $)	12 Months Ended
Document and Entity Information (USD $)	Apr. 30, 2013	Jul. 05, 2013	Oct. 31, 2012
Document And Entity Information
Entity Registrant Name	PEREGRINE PHARMACEUTICALS INC
Entity Central Index Key	0000704562
Document Type	10-K
Document Period End Date	Apr. 30, 2013
Amendment Flag	false
Current Fiscal Year End Date	--04-30
Is Entity a Well-known Seasoned Issuer?	No
Is Entity a Voluntary Filer?	No
Is Entity's Reporting Status Current?	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 100,013,745
Entity Common Stock, Shares Outstanding		151,602,765
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2013

CONSOLIDATED BALANCE SHEETS (USD $)	Apr. 30, 2013	Apr. 30, 2012
CURRENT ASSETS:
Cash and cash equivalents	$ 35,204,000	$ 18,033,000
Trade and other receivables, net	1,662,000	2,353,000
Inventories	4,339,000	3,611,000
Prepaid expenses and other current assets, net	709,000	795,000
Total current assets	41,914,000	24,792,000
PROPERTY:
Leasehold improvements	1,383,000	1,383,000
Laboratory equipment	5,441,000	4,967,000
Furniture, fixtures, office equipment and software	2,627,000	2,287,000
Property, gross	9,451,000	8,637,000
Less accumulated depreciation and amortization	(6,773,000)	(5,737,000)
Property, net	2,678,000	2,900,000
Other assets	466,000	570,000
TOTAL ASSETS	45,058,000	28,262,000
CURRENT LIABILITIES:
Accounts payable	2,821,000	3,492,000
Accrued clinical trial and related fees	930,000	2,111,000
Accrued payroll and related costs	3,582,000	2,468,000
Deferred revenue, current portion	4,171,000	3,651,000
Customer deposits	8,059,000	4,865,000
Other current liabilities	998,000	1,052,000
Total current liabilities	20,561,000	17,639,000
Deferred revenue, less current portion	292,000	361,000
Other long-term liabilities	445,000	779,000
Commitments and contingencies
STOCKHOLDERS' EQUITY:
Preferred stock - $.001 par value; authorized 5,000,000 shares; non-voting; none issued	0	0
Common stock - $.001 par value; authorized 325,000,000 shares; outstanding - 143,768,946 and 101,421,365, respectively	143,000	101,000
Additional paid-in-capital	391,521,000	347,506,000
Accumulated deficit	(367,904,000)	(338,124,000)
Total stockholders' equity	23,760,000	9,483,000
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 45,058,000	$ 28,262,000

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Apr. 30, 2013	Apr. 30, 2012
Statement of Financial Position [Abstract]
Preferred stock par value (in Dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock par value (in Dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	325,000,000	325,000,000
Common stock, shares outstanding	143,768,946	101,421,365

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (USD $)	12 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
REVENUES:
Contract manufacturing revenue	$ 21,333,000	$ 14,783,000	$ 8,502,000
Government contract revenue	0	0	4,640,000
License revenue	350,000	450,000	350,000
Total revenues	21,683,000	15,233,000	13,492,000
COSTS AND EXPENSES:
Cost of contract manufacturing	12,595,000	10,153,000	7,296,000
Research and development	24,306,000	35,688,000	29,462,000
Selling, general and administrative	13,134,000	11,462,000	11,421,000
Total costs and expenses	50,035,000	57,303,000	48,179,000
LOSS FROM OPERATIONS	(28,352,000)	(42,070,000)	(34,687,000)
OTHER INCOME (EXPENSE):
Interest and other income	322,000	41,000	1,052,000
Interest and other expense	(54,000)	(90,000)	(516,000)
Loss on early extinguishment of debt	(1,696,000)	0	0
NET LOSS	(29,780,000)	(42,119,000)	(34,151,000)
COMPREHENSIVE LOSS	$ (29,780,000)	$ (42,119,000)	$ (34,151,000)
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING	120,370,333	83,572,761	60,886,392
BASIC AND DILUTED LOSS PER COMMON SHARE	$ (0.25)	$ (0.50)	$ (0.56)

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $)	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Total
Beginning Balance, Value at Apr. 30, 2010	$ 53,000	$ 275,208,000	$ (261,854,000)	$ 13,407,000
Beginning Balance, Shares at Apr. 30, 2010	53,094,896
Common stock issued for cash, net of issuance costs, Shares	16,364,429
Common stock issued for cash, net of issuance costs, Value	17,000	33,070,000		33,087,000
Common stock issued upon exercise of options, Shares	20,750
Common stock issued upon exercise of options, Value		44,000		44,000
Common stock issued upon exercise of warrants, Shares	74,802
Common stock issued upon exercise of warrants, Value
Common stock issued for services, Shares	28,921
Common stock issued for services, Value		60,000		60,000
Common stock issued under restricted stock awards, Shares	148,500
Common stock issued under restricted stock awards, Value
Common stock issued under Employee Stock Purchase Plan, Shares	104,844
Common stock issued under Employee Stock Purchase Plan, Value		134,000		134,000
Share-based compensation		2,837,000		2,837,000
Net loss			(34,151,000)	(34,151,000)
Ending Balance, Value at Apr. 30, 2011	70,000	311,353,000	(296,005,000)	15,418,000
Ending Balance, Shares at Apr. 30, 2011	69,837,142
Common stock issued for cash, net of issuance costs, Shares	31,126,182
Common stock issued for cash, net of issuance costs, Value	31,000	33,148,000		33,179,000
Common stock issued under Employee Stock Purchase Plan, Shares	458,041
Common stock issued under Employee Stock Purchase Plan, Value		236,000		236,000
Share-based compensation		2,769,000		2,769,000
Net loss			(42,119,000)	(42,119,000)
Ending Balance, Value at Apr. 30, 2012	101,000	347,506,000	(338,124,000)	9,483,000
Ending Balance, Shares at Apr. 30, 2012	101,421,365
Common stock issued for cash, net of issuance costs, Shares	41,184,043
Common stock issued for cash, net of issuance costs, Value	41,000	39,481,000		39,522,000
Common stock issued upon exercise of options, Shares	118,555			(118,555)
Common stock issued upon exercise of options, Value		96,000		96,000
Common stock issued upon exercise of warrants, Shares	46,427
Common stock issued upon exercise of warrants, Value
Common stock issued under Employee Stock Purchase Plan, Shares	998,556
Common stock issued under Employee Stock Purchase Plan, Value	1,000	533,000		534,000
Fair market value of warrants issued with notes payable		470,000		470,000
Share-based compensation		3,435,000		3,435,000
Net loss			(29,780,000)	(29,780,000)
Ending Balance, Value at Apr. 30, 2013	$ 143,000	$ 391,521,000	$ (367,904,000)	$ 23,760,000
Ending Balance, Shares at Apr. 30, 2013	143,768,946

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (29,780,000)	$ (42,119,000)	$ (34,151,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation	3,435,000	2,769,000	2,837,000
Depreciation and amortization	1,087,000	908,000	652,000
Loss on early extinguishment of debt	1,696,000	0	0
Amortization of discount on notes payable and debt issuance costs	0	33,000	235,000
Amortization of expenses paid in shares of common stock	0	0	956,000
Common stock issued for services	0	0	40,000
Loss on sale of property	8,000	2,000	0
Changes in operating assets and liabilities:
Trade and other receivables, net	691,000	(964,000)	92,000
Government contract receivables	0	93,000	274,000
Inventories	(728,000)	1,673,000	(2,161,000)
Prepaid expenses and other current assets, net	86,000	158,000	95,000
Other non-current assets	2,000	789,000	(7,000)
Accounts payable	(691,000)	(601,000)	608,000
Accrued clinical trial site and related fees	(1,181,000)	(181,000)	984,000
Accrued payroll and related expenses	1,114,000	1,013,000	(168,000)
Deferred revenue	451,000	(2,237,000)	3,843,000
Deferred government contract revenue	0	0	(78,000)
Customer deposits	3,194,000	3,106,000	(859,000)
Other accrued expenses and current liabilities	24,000	(62,000)	372,000
Other long-term liabilities	(334,000)	(258,000)	(26,000)
Net cash used in operating activities	(20,926,000)	(35,878,000)	(26,462,000)
CASH FLOWS FROM INVESTING ACTIVITIES:
Property acquisitions	(853,000)	(1,554,000)	(912,000)
Decrease (increase) in other assets	102,000	383,000	(435,000)
Net cash used in investing activities	(751,000)	(1,171,000)	(1,347,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net of issuance costs of $1,232,000, $1,151,000, and $769,000, respectively	39,522,000	33,179,000	33,087,000
Proceeds from issuance of notes payable, net of issuance costs of $251,000	14,749,000	0	0
Proceeds from issuance of common stock under Employee Stock Purchase Plan	534,000	236,000	134,000
Proceeds from exercise of stock options	96,000	0	44,000
Principal payments on notes payable	(15,000,000)	(1,333,000)	(2,000,000)
Payment of final fee on notes payable	(975,000)	0	0
Principal payments on capital leases	(78,000)	(75,000)	(62,000)
Net cash provided by financing activities	38,848,000	32,007,000	31,203,000
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	17,171,000	(5,042,000)	3,394,000
CASH AND CASH EQUIVALENTS, Beginning of year	18,033,000	23,075,000	19,681,000
CASH AND CASH EQUIVALENTS, End of year	35,204,000	18,033,000	23,075,000
SUPPLEMENTAL INFORMATION:
Interest paid	46,000	68,000	301,000
SCHEDULE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Fair market value of warrants issued in connection with notes payable	470,000	0	0
Accounts payable for purchase of property	20,000	47,000	300,000
Property acquired under capital lease	0	0	180,000
Other asset in exchange for future services	$ 0	$ 0	$ 233,000

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) (USD $)	12 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Statement of Cash Flows [Abstract]
Common stock issuance costs	$ 1,232,000	$ 1,151,000	$ 769,000
Note payable issuance costs	$ 251,000	$ 0	$ 0

1. ORGANIZATION AND BUSINESS DESCRIPTION

12 Months Ended

Apr. 30, 2013

Organization And Business Description

1. ORGANIZATION AND BUSINESS DESCRIPTION

ORGANIZATION AND BUSINESS DESCRIPTION

Organization – In this Annual Report, “Peregrine,” “Company,” “we,” “us,” and “our,” refer to Peregrine Pharmaceuticals, Inc., and our wholly owned subsidiary, Avid Bioservices, Inc. (“Avid”). Peregrine was incorporated under the laws of the state of California in June 1981, reincorporated in Delaware in September 1996 and commenced operations of Avid in January 2002.

Business Description – We are a biopharmaceutical company with a portfolio of innovative monoclonal antibodies in clinical trials focused on the treatment and diagnosis of cancer. We are advancing two oncology programs with our lead product candidates, bavituximab and Cotara, for the treatment of various cancers. In addition, we are advancing our lead molecular imaging agent, 124I-PGN650, in an exploratory clinical trial for the imaging of multiple solid tumor types.

With respect to our bavituximab oncology program, we are focused on advancing bavituximab into Phase III clinical development by calendar year-end 2013 for the treatment of second-line non-small cell lung cancer (“NSCLC”) as our lead indication. In May 2013, we reached an agreement with the U.S. Food and Drug Administration (“FDA”) on the Phase III trial design. In addition, we are conducting a number of other trials with bavituximab in combination with other therapies in multiple oncology indications as potential secondary indications for bavituximab.

With respect to our Cotara oncology program, we conducted a Phase II trial using Cotara for the treatment of recurrent glioblastoma multiforme (“GBM”). In addition in December 2012, we reached an agreement with the FDA on the design of a single pivotal trial to potentially support product registration for Cotara in the treatment of recurrent GBM. We are actively seeking potential partners as we look to further advance Cotara into Phase III development. In addition, Cotara has been granted orphan drug status and fast track designation for the treatment of GBM and anaplastic astrocytoma by the FDA.

With respect to our imaging program, we are currently conducting an open-label, single-center clinical trial under an exploratory Investigational New Drug Application filed with the FDA for our lead imaging agent 124I-PGN650 for the imaging of multiple solid tumor types.

In addition to our clinical research and development efforts, we operate a wholly-owned cGMP (current Good Manufacturing Practices) contract manufacturing subsidiary, Avid. Avid is a Contract Manufacturing Organization (“CMO”) that provides fully integrated services from cell line development to commercial cGMP biomanufacturing for Peregrine and its third-party clients. In addition to generating revenue from providing a comprehensive range of biomanufacturing services to third-party clients, Avid is strategically integrated with Peregrine to manufacture all clinical products to support our company-sponsored and investigator-sponsored trials while also preparing for potential commercial launch of bavituximab and Cotara.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

12 Months Ended

Apr. 30, 2013

Accounting Policies [Abstract]

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation - The accompanying consolidated financial statements include the accounts of Peregrine and its wholly-owned subsidiary, Avid. All intercompany balances and transactions have been eliminated.

Use of Estimates - The preparation of our financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from these estimates.

Liquidity and Financial Condition - At April 30, 2013, we had $35,204,000 in cash and cash equivalents. We have expended substantial funds on the research and development of our product candidates, and funding the operations of Avid. As a result, we have historically experienced negative cash flows from operations since our inception and we expect the negative cash flows from operations to continue in the foreseeable future. Our net losses incurred during the past three fiscal years ended April 30, 2013, 2012 and 2011, amounted to $29,780,000, $42,119,000, and $34,151,000, respectively. Therefore, unless and until we are able to generate sufficient revenues from Avid’s contract manufacturing services and/or from the sale and/or licensing of our products under development, we expect such losses to continue in the foreseeable future.

Therefore, our ability to continue to fund our clinical trials and development efforts is highly dependent on the amount of cash and cash equivalents on hand combined with our ability to raise additional capital to support our future operations through one or more methods, including but not limited to, issuing additional equity or debt.

Historically, we have funded a significant portion of our operations through the issuance of equity. During fiscal year 2013, we raised $40,754,000 in aggregate gross proceeds under two separate At Market Sales Issuance Agreements (Note 6). Subsequent to April 30, 2013 and through July 11, 2013, we raised an additional $12,729,000 in aggregate gross proceeds under an At Market Issuance Sales Agreement (Note 6). With these additional proceeds, we currently estimate that we have sufficient cash resources to meet our anticipated cash needs to fund our operations through at least fiscal year 2014 based on our current projections, which includes the initiation of our pivotal Phase III clinical trial of bavituximab combined with docetaxel in second-line NSCLC, projected cash inflows under signed contracts with existing customers of Avid and assuming we raise no additional capital from the capital markets or other potential sources.

However, our ability to continue to fund our clinical trials and development efforts in future years, including costs to fund our pivotal Phase III second-line NSCLC trial beyond fiscal year 2014, is highly dependent on our ability to raise additional capital to support our future operations through one or more methods, including but not limited to, financing our operations through the issuance of equity, securing new funding through the issuance of debt, licensing or partnering our products in development, or increasing revenue from our wholly-owned subsidiary, Avid. While we will continue to explore these potential opportunities, we may not be successful in securing debt financing, licensing or partnering our products in development, or generating additional revenue from Avid to complete the research, development, and clinical testing of our product candidates. Even if we are successful in obtaining debt financing, it may involve restrictive covenants on the operation of our business and require significant interest payments.

With respect to our ability to raise additional capital from the issuance of equity, as of July 11, 2013, we have an effective shelf registration statement on Form S-3, under which we may issue, from time to time, in one or more offerings, shares of our common stock for gross proceeds of up to $123,898,000. However, our ability to raise additional capital in the equity markets is dependent on a number of factors, including, but not limited to, the market demand for our common stock. The market demand or liquidity of our common stock is subject to a number of risks and uncertainties, including but not limited to, negative economic conditions, adverse market conditions, adverse clinical trial results and significant delays in one or more clinical trials. If our ability to access the capital markets becomes severely restricted, it could have a negative impact on our business plans, including our clinical trial programs and other research and development activities. In addition, even if we are able to raise additional capital, it may not be at a price or on terms that are favorable to us.

Cash and Cash Equivalents - We consider all highly liquid, short-term investments with an initial maturity of three months or less to be cash equivalents.

Trade and Other Receivables – Trade and other receivables are recorded at the invoiced amount net of an allowance for doubtful accounts, if necessary. Trade and other receivables, net, at April 30, consist of the following:

	2013		2012
Trade receivables⁽¹⁾	$	1,642,000	$	2,264,000
Other receivables, net		20,000		89,000
Trade and other receivables, net	$	1,662,000	$	2,353,000

^{____________________}

⁽¹⁾Represents amounts billed for contract manufacturing services provided by Avid.

Allowance for Doubtful Accounts - We continually monitor our allowance for doubtful accounts for all receivables. We apply judgment in assessing the ultimate realization of our receivables and we estimate an allowance for doubtful accounts based on various factors, such as, the aging of accounts receivable balances, historical experience, and the financial condition of our customers. Based on our analysis of our receivables as of April 30, 2013 and 2012, we determined an allowance for doubtful accounts of $16,000 and $19,000, respectively, was necessary with respect to trade and other receivables.

In addition, amounts billed under our former government contract with Transformational Medical Technologies (“TMT”) of the U.S. Department of Defense’s Defense Threat Reduction Agency, which expired on April 15, 2011, included the reimbursement for provisional rates covering allowable indirect overhead and general and administrative costs (“Indirect Rates”). These Indirect Rates were initially estimated based on financial projections and were subject to change based on actual costs incurred during each fiscal year. In addition, these Indirect Rates are subject to annual audits by the Defense Contract Audit Agency (“DCAA”) for cost reimbursable type contracts. Upon the expiration of this contract, we recorded an unbilled receivable of $92,000 pertaining to the difference calculated between the estimated and actual Indirect Rates, which amount at April 30, 2013 and 2012, is included in prepaid expenses and other current assets. However, due to the uncertainty of its collectability, we determined it appropriate to record a corresponding allowance for doubtful accounts with respect to unbilled Indirect Rates in the amount of $92,000 at April 30, 2013 and 2012.

Prepaid Research and Development Expenses - Our prepaid research and development expenses represent deferred and capitalized pre-payments to secure the receipt of future research and development services. These pre-payments are recognized as an expense in the period that the services are performed. We assess our prepaid research and development expenses for impairment when events or changes in circumstances indicate that the carrying amount of the prepaid expense may not be recoverable or provide future economic benefit.

Inventories - Inventories are stated at the lower of cost or market and primarily include raw materials, direct labor and overhead costs (work-in-process) associated with our wholly owned subsidiary, Avid. Cost is determined by the first-in, first-out method. Inventories consist of the following at April 30,:

	2013		2012
Raw materials,	$	2,169,000	$	1,966,000
Work-in-process		2,170,000		1,645,000
Total inventories,	$	4,339,000	$	3,611,000

Property - Property is recorded at cost. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the related asset, generally ranging from three to ten years. Amortization of leasehold improvements is calculated using the straight-line method over the shorter of the estimated useful life of the asset or the remaining lease term.

Concentrations of Credit Risk and Customer Base - Financial instruments that potentially subject us to a significant concentration of credit risk consist of cash and cash equivalents and trade receivables. We maintain our cash balances primarily with one major commercial bank and our deposits held with the bank exceed the amount of government insurance limits provided on our deposits. We are exposed to credit risk in the event of default by the major commercial bank holding our cash balances to the extent of the cash amount recorded on the accompanying consolidated balance sheet.

Our trade receivables from amounts billed for contract manufacturing services provided by Avid have historically been derived from a small customer base. Most contracts require up-front payments and installment payments during the service period. We perform periodic evaluations of the financial condition of our ongoing customers and generally do not require collateral, but we can terminate any contract if a material default occurs. Approximately 97% of our trade receivable balance as of April 30, 2013, represents amounts due from two customers. Approximately 98% of our trade receivable balance as of April 30, 2012, represents amounts due from three customers.

In addition, contract manufacturing revenue generated by Avid has historically been derived from a small customer base (Note 11). These customers typically do not enter into long-term contracts because their need for drug supply depends on a variety of factors, including the drug’s stage of development, their financial resources, and, with respect to commercial drugs, demand for the drug in the market. Our future results of operations could be adversely affected if revenue from any one of our primary customers is significantly reduced or eliminated.

Comprehensive Loss - Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources. Comprehensive loss is equal to our net loss for all periods presented.

Impairment - Long-lived assets are reviewed for impairment in accordance with authoritative guidance for impairment or disposal of long-lived assets. Long-lived assets are reviewed for events or changes in circumstances, which indicate that their carrying value may not be recoverable. Long-lived assets are reported at the lower of carrying amount or fair value less cost to sell.

Fair Value of Financial Instruments - The carrying amounts in the accompanying consolidated balance sheet for cash and cash equivalents, accounts receivable, accounts payable, and accrued liabilities approximate their fair values due to their short-term maturities.

Fair Value Measurements - We determine fair value measurements in accordance with the authoritative guidance for fair value measurements and disclosures for all assets and liabilities within the scope of this guidance. This guidance, which among other things, defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The guidance prioritizes the inputs used in measuring fair value into the following hierarchy:

Level 1 – Quoted prices in active markets for identical assets or liabilities.

Level 2 – Observable inputs other than quoted prices included in Level 1, such as assets or liabilities whose values are based on quoted market prices in markets where trading occurs infrequently or whose values are based on quoted prices of instruments with similar attributes in active markets.

Level 3 – Unobservable inputs that are supported by little or no market activity and significant to the overall fair value measurement.

As of April 30, 2013 and 2012, we do not have any Level 2 or Level 3 financial assets or liabilities and our cash and cash equivalents are carried at fair value based on quoted market prices for identical securities (Level 1 input).

Customer Deposits - Customer deposits primarily represents advance billings and/or payments received from Avid’s third-party customers prior to the initiation of contract manufacturing services.

Revenue Recognition - We currently derive revenue from the following two sources: (i) contract manufacturing services provided by Avid, and (ii) licensing revenue related to agreements associated with Peregrine’s technologies under development. In addition, from June 30, 2008 through April 15, 2011, we derived government contract revenue from services provided under a government contract awarded to us through the TMT of the U.S. Department of Defense’s Defense Threat Reduction Agency. The government contract with the TMT expired on April 15, 2011.

We recognize revenue in accordance with the authoritative guidance for revenue recognition. We recognize revenue when all of the following criteria are met: (i) persuasive evidence of an arrangement exists, (ii) delivery (or passage of title) has occurred or services have been rendered, (iii) the seller's price to the buyer is fixed or determinable, and (iv) collectability is reasonably assured. We also comply with the authoritative guidance for revenue recognition regarding arrangements with multiple deliverables.

In addition, we also follow the authoritative guidance when reporting revenue as gross when we act as a principal versus reporting revenue as net when we act as an agent. For transactions in which we act as a principal, have discretion to choose suppliers, bear credit risk and perform a substantive part of the services, revenue is recorded at the gross amount billed to a customer and costs associated with these reimbursements are reflected as a component of cost of sales for contract manufacturing services and as a component of research and development expense for services provided under our former contract with the TMT (contract expired on April 15, 2011).

Contract Manufacturing Revenue

Revenue associated with contract manufacturing services provided by Avid is recognized once the service has been rendered and/or upon shipment (or passage of title) of the product to the customer. On occasion, we recognize revenue on a “bill-and-hold” basis in accordance with the authoritative guidance. Under “bill-and-hold” arrangements, revenue is recognized once the product is complete and ready for shipment, title and risk of loss has passed to the customer, management receives a written request from the customer for “bill-and-hold” treatment, the product is segregated from other inventory, and no further performance obligations exist.

Any amounts received prior to satisfying our revenue recognition criteria are recorded as deferred revenue in the accompanying consolidated financial statements. We also record a provision for estimated contract losses, if any, in the period in which they are determined.

License Revenue

Revenue associated with licensing agreements primarily consists of non-refundable upfront license fees, non-refundable annual license fees and milestone payments. Non-refundable upfront license fees received under license agreements, whereby continued performance or future obligations are considered inconsequential to the relevant license technology, are recognized as revenue upon delivery of the technology. If a licensing agreement has multiple elements, we analyze each element of our licensing agreements and consider a variety of factors in determining the appropriate method of revenue recognition of each element.

Multiple Element Arrangements. Prior to the adoption of Accounting Standards Update (“ASU”) No. 2009-13 on May 1, 2011, if a license agreement has multiple element arrangements, we analyze and determine whether the deliverables, which often include performance obligations, can be separated or whether they must be accounted for as a single unit of accounting in accordance with the authoritative guidance. Under multiple element arrangements, we recognize revenue for delivered elements only when the delivered element has stand-alone value and we have objective and reliable evidence of fair value for each undelivered element. If the fair value of any undelivered element included in a multiple element arrangement cannot be objectively determined, the arrangement would then be accounted for as a single unit of accounting, and revenue is recognized over the estimated period of when the performance obligation(s) are performed.

In addition, under certain circumstances, when there is objective and reliable evidence of the fair value of the undelivered items in an arrangement, but no such evidence for the delivered items, we utilize the residual method to allocate the consideration received under the arrangement. Under the residual method, the amount of consideration allocated to delivered items equals the total arrangement consideration less the aggregate fair value of the undelivered items, and revenue is recognized upon delivery of the undelivered items based on the relative fair value of the undelivered items.

For new licensing agreements or material modifications of existing licensing agreements entered into after May 1, 2011, we follow the provisions of ASU No. 2009-13. If a licensing agreement includes multiple elements, we identify which deliverables represent separate units of accounting, and then determine how the arrangement consideration should be allocated among the separate units of accounting, which may require the use of significant judgment.

If a licensing agreement includes multiple elements, a delivered item is considered a separate unit of accounting if both of the following criteria are met:

The delivered item has value to the licensing partner on a standalone basis based on the consideration of the relevant facts and circumstances for each agreement;

If the arrangement includes a general right of return relative to the delivered item, delivery or performance of the undelivered item is considered probable and substantially in the Company’s control.

Arrangement consideration is allocated at the inception of the agreement to all identified units of accounting based on their relative selling price. The relative selling price for each deliverable is determined using vendor specific objective evidence (“VSOE”) of selling price or third-party evidence of selling price if VSOE does not exist. If neither VSOE nor third-party evidence of selling price exists, we use our best estimate of the selling price for the deliverable. The amount of allocable arrangement consideration is limited to amounts that are fixed or determinable. The consideration received is allocated among the separate units of accounting, and the applicable revenue recognition criteria are applied to each of the separate units. Changes in the allocation of the sales price between delivered and undelivered elements can impact revenue recognition but do not change the total revenue recognized under any agreement.

Milestone Payments. Prior to the adoption of ASU No. 2010-17 on May 1, 2011, milestone payments were recognized as revenue upon the achievement of the specified milestone, provided that (i) the milestone event was substantive in nature and the achievement of the milestone was not reasonably assured at the inception of the agreement, (ii) the fees were non-refundable, and (iii) there was no continuing performance obligations associated with the milestone payment.

Effective May 1, 2011, we adopted on a prospective basis the Milestone Method under ASU No. 2010-17 for new licensing agreements or material modifications of existing licensing agreements entered into after May 1, 2011. Under the Milestone Method, we recognize consideration that is contingent upon the achievement of a milestone in its entirety as revenue in the period in which the milestone is achieved only if the milestone is substantive in its entirety. A milestone is considered substantive when it meets all of the following criteria:

The consideration is commensurate with either the entity’s performance to achieve the milestone or the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the entity’s performance to achieve the milestone;

The consideration relates solely to past performance; and

The consideration is reasonable relative to all of the deliverables and payment terms within the arrangement.

A milestone is defined as an event (i) that can only be achieved based in whole or in part on either the entity’s performance or on the occurrence of a specific outcome resulting from the entity’s performance, (ii) for which there is substantive uncertainty at the date the arrangement is entered into that the event will be achieved and (iii) that would result in additional payments being due to the Company.

The provisions of ASU No. 2010-17 do not apply to contingent consideration for which payment is either contingent solely upon the passage of time or the result of a counterparty’s performance. We will assess the nature of, and appropriate accounting for, these payments on a case-by-case basis in accordance with the applicable authoritative guidance for revenue recognition.

Any milestone payments received prior to satisfying these revenue recognition criteria were recorded as deferred revenue in the accompanying consolidated financial statements.

Government Contract Revenue

Government contract revenue was derived from a former government contract (the “Government Contract”) awarded to us on June 30, 2008, through the TMT of the U.S. Department of Defense’s Defense Threat Reduction Agency. The purpose of the Government Contract, which expired on April 15, 2011, was to test and develop bavituximab and an equivalent fully human antibody as potential broad-spectrum treatments for viral hemorrhagic fever infections. As of April 30, 2011, we had recognized $24,149,000 in total government contract revenue under this Government Contract including $4,640,000 recognized during fiscal year 2011.

The Government Contract was classified as a “cost-plus-fixed-fee” contract. We recognized government contract revenue in accordance with the authoritative guidance for revenue recognition including the authoritative guidance specific to federal government contracts. Reimbursable costs under the contract primarily include direct labor, subcontract costs, materials, equipment, travel and indirect costs. In addition, we received a fixed fee for our efforts equal to 9.9% of the reimbursable costs incurred under the Government Contract, which was unconditionally earned as allowable costs were billed and was not contingent on success factors. Reimbursable costs under this Government Contract, including the fixed fee, were generally recognized as revenue in the period the reimbursable costs are incurred and become billable. However, when amounts billable, including the fixed fee, were not reasonably related to the proportionate performance of the total work or services to be performed, we recognized revenue on a proportional performance basis. In addition, reimbursable costs, including the fixed fee, associated with manufacturing services were recognized as revenue once delivery (or passage of title) had occurred.

Other Income - Other income for the fiscal year ended April 30, 2011, includes a grant of $978,000 awarded to us under Section 48D of the Internal Revenue Code as reimbursement for four separate qualifying therapeutic discovery projects, which we applied for under the Patient Protection and Affordable Care Act of 2010.

Research and Development Expenses - Research and development costs are charged to expense when incurred in accordance with the authoritative guidance for research and development costs. Research and development expenses primarily include (i) payroll and related costs associated with research and development personnel, (ii) costs related to clinical and preclinical testing of our technologies under development, (iii) costs to develop and manufacture the product candidates, including raw materials and supplies, product testing, depreciation, and facility related expenses, (iv) expenses for research services provided by universities and contract laboratories, including sponsored research funding, and (v) other research and development expenses.

Accrued Clinical Trial and Related Fees - We accrue clinical trial and related fees based on work performed in connection with advancing our clinical trials, which relies on estimates and/or representations from clinical research organizations (“CROs”), hospitals, consultants and other clinical trial related vendors. We maintain regular communication with our vendors, including our CROs, and gauge the reasonableness of estimates provided. However, actual clinical trial costs may differ from estimated clinical trial costs and are adjusted for in the period in which they become known. There were no material adjustments for a change in estimate to research and development expenses in the accompanying consolidated financial statements in any of the three years ended April 30, 2013.

Share-based Compensation - We account for stock options and other share-based awards granted under our equity compensation plans in accordance with the authoritative guidance for share-based compensation. The estimated fair value of share-based payments to employees in exchange for services is measured at the grant date, using a fair value based method, and is recognized as expense on a straight-line basis over the requisite service periods. Share-based compensation expense recognized during the period is based on the value of the portion of the share-based payment that is ultimately expected to vest during the period. Share-based compensation expense for a share-based payment with a performance condition is recognized on a straight-line basis over the requisite service period when the achievement of the performance condition is determined to be probable. If a performance condition is not determined to be probable or is not met, no share-based compensation is recognized and any previously recognized compensation expense is reversed.

In addition, we periodically grant stock options and other share-based awards to non-employee consultants, which we account for in accordance with the authoritative guidance for share-based compensation. The cost of non-employee services received in exchange for share-based awards are measured based on either the fair value of the consideration received or the fair value of the share-based award issued, whichever is more reliably measurable. In addition, guidance requires share-based compensation related to unvested options and awards issued to non-employees to be recalculated at the end of each reporting period based upon the fair market value on that date until the share-based award has vested, and any adjustment to share-based compensation resulting from the re-measurement is recognized in the current period. See Note 7 for further discussion regarding share-based compensation.

Income Taxes - We utilize the liability method of accounting for income taxes in accordance with authoritative guidance for accounting for income taxes. Under the liability method, deferred taxes are determined based on the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates. A valuation allowance is provided when it is more likely than not that some portion or the entire deferred tax asset will not be realized.

Basic and Dilutive Net Loss Per Common Share - Basic net loss per common share is computed by dividing our net loss by the weighted average number of common shares outstanding during the period excluding the dilutive effects of stock options, unvested stock awards, common shares expected to be issued under our employee stock purchase plan, and warrants in accordance with the authoritative guidance. Diluted net loss per common share is computed by dividing the net loss by the sum of the weighted average number of common shares outstanding during the period plus the potential dilutive effects of stock options, unvested stock awards, common shares expected to be issued under our employee stock purchase plan, and warrants outstanding during the period calculated in accordance with the treasury stock method, but are excluded if their effect is anti-dilutive. Because the impact of options, awards and warrants are anti-dilutive during periods of net loss, there was no difference between basic and diluted loss per share amounts for the three years ended April 30, 2013.

The calculation of weighted average diluted shares outstanding excludes the dilutive effect of the following weighted average outstanding stock options, stock awards, common shares expected to be issued under our employee stock purchase plan, and warrants since their impact are anti-dilutive during periods of net loss, resulting in an anti-dilutive effect as of April 30,:

	2013		2012		2011
Stock options and awards		3,505,777		96,591		85,361
Employee stock purchase plan		307,501		110,469		20,327
Warrants		–		–		68,991
Total		3,813,278		207,060		174,679

The calculation of weighted average diluted shares outstanding also excludes weighted average outstanding stock options, stock awards and warrants to purchase 5,860,305, 5,970,393, and 4,338,813 shares of common stock for fiscal years ended April 30, 2013, 2012, and 2011, respectively, as their exercise prices were greater than the average market price of our common stock during the respective periods, resulting in an anti-dilutive effect.

Subsequent to April 30, 2013 and through July 11, 2013, we issued an aggregate of 7,927,016 shares of our common stock (Note 6), which are not included in the calculation of basic and dilutive net loss per common share for the year ended April 30, 2013.

Adoption of Recent Accounting Pronouncements

Effective May 1, 2012, we adopted Financial Accounting Standards Board’s (“FASB”) ASU No. 2011-05, Comprehensive Income (Topic 220): Presentation of Comprehensive Income and ASU No. 2011-12, Comprehensive Income (Topic 220): Deferral of the Effective Date for Amendments to the Presentation of Reclassifications of Items Out of Accumulated Other Comprehensive Income in ASU No. 2011-5. In these updates, an entity has the option to present the total of comprehensive income, the components of net income, and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. In both choices, an entity is required to present each component of net income along with total net income, each component of other comprehensive income along with a total for other comprehensive income, and a total amount for comprehensive income. ASU No. 2011-05 eliminates the option to present the components of other comprehensive income as part of the statement of changes in stockholders’ equity. The amendments in ASU No. 2011-05 do not change the items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income. The adoption of ASU Nos. 2011-05 and 2011-12 did not have a material impact on our consolidated financial statements. We have presented comprehensive loss in the accompanying consolidated statements of operations and comprehensive loss.

Pending Adoption of Recent Accounting Pronouncements

In February 2013, the FASB issued ASU No. 2013-02, Other Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. ASU No. 2013-02 does not change the current requirements for reporting net income or other comprehensive income in financial statements, however, it does require an entity to report the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in net income if the amounts are required to be reclassified in their entirety to net income. For other amounts that are not required to be reclassified in their entirety to net income in the same reporting period, an entity is required to cross-reference to other disclosures that provide additional detail about those amounts. This guidance will be effective for reporting periods beginning after December 15, 2012, which will be our fiscal year 2014 (or May 1, 2013). We do not expect the adoption of this guidance to have a material impact on our consolidated financial statements.

3. NOTE PAYABLE AND CAPITAL LEASE OBLIGATIONS

12 Months Ended

Apr. 30, 2013

Debt and Capital Lease Obligations [Abstract]

3. NOTE PAYABLE AND CAPITAL LEASE OBLIGATIONS

NOTE PAYABLE AND CAPITAL LEASE OBLIGATIONS

August 2012 Note Payable Obligation

On August 30, 2012, we entered into a loan and security agreement (the “Loan Agreement”) with Oxford Finance LLC, MidCap Financial SBIC LP, and Silicon Valley Bank (collectively, the “Lenders”) for up to $30,000,000 in total funding available in two $15,000,000 tranches. The Loan Agreement was secured by a first-priority security interest in substantially all of our assets, excluding our intellectual property and our rights under license agreements granting us rights to intellectual property. On August 30, 2012, we received initial funding of $15,000,000 under the Loan Agreement, excluding debt issuance costs of $251,000.

On September 24, 2012, we received a written notice of default (“Notice of Default”) from the Lenders, with respect to the Loan Agreement. The Notice of Default was triggered by a material adverse change under the Loan Agreement due to our discovery of major discrepancies in treatment group coding by an independent third-party vendor responsible for distribution of blinded investigational product used in our bavituximab Phase II second-line NSCLC clinical trial. Pursuant to the terms of the Notice of Default, all amounts due under the Loan Agreement were declared immediately due and payable by the Lenders. On September 25, 2012, we paid the Lenders all obligations declared due and payable under the Loan Agreement, including outstanding principal of $15,000,000, accrued interest thereon at the Loan Agreement’s applicable fixed rate of 7.95% per annum, plus a final payment fee equal to 6.5% of the principal amount funded (or $975,000), upon which, the Loan Agreement was terminated.

In addition, under the Loan Agreement, we issued to the Lenders six-year warrants to purchase shares of our common stock upon the funding of each tranche in an amount equal to 4.50% of the amount of such tranche divided by the exercise price, which is the lower of the average closing price of our common stock for the 10 business days immediately prior to the funding date for such tranche or the closing price on the day prior to such funding date. Therefore, upon the initial funding under the Loan Agreement, we issued the Lenders warrants to purchase an aggregate of 273,280 shares of our common stock at a per share price of $2.47, which are exercisable on a cash or cashless basis, and will expire on August 30, 2018. The fair value of the warrants issued was $470,000 and was calculated using a Black-Scholes valuation model with the following assumptions: risk-free interest rate of 0.87%; expected volatility of 80.20%; expected term of six years; and a dividend yield of 0%. The fair value of the warrants issued was initially recorded as a debt discount with a corresponding increase to additional paid-in capital. As of April 30, 2013, the warrants issued under the Loan Agreement were outstanding and exercisable (Note 8).

Upon the termination of the Loan Agreement, we recorded a loss on the early extinguishment of debt of $1,696,000, which consisted of the final payment fee of $975,000, the unamortized debt discount associated with the fair value of the warrants issued to the Lenders of $470,000, and the unamortized aggregate debt issuance costs of $251,000. The loss on the early extinguishment of debt is included in the accompanying consolidated statements of operations and comprehensive loss for the fiscal year ended April 30, 2013.

December 2008 Note Payable Obligation

On December 9, 2008, we borrowed $5,000,000 from MidCap Financial LLC and BlueCrest Capital Finance, L.P (collectively, the “Lenders”) under a term loan (the “Term Loan”) payable over three years. On December 1, 2011, the loan balance was paid in full.

In connection with the term loan, we issued to the Lenders five-year warrants to purchase an aggregate of 338,410 shares of our common stock at an exercise price of $1.4775 per share. The fair value of the warrants issued was $414,000 and was calculated using a Black-Scholes valuation model with the following assumptions: risk-free interest rate of 2.00%; expected volatility of 70.72%; an expected term of five years; and a dividend yield of 0%. The fair value of the warrants issued was initially recorded as a debt discount with a corresponding increase to additional paid-in capital. The debt discount was amortized as a non-cash interest expense over the term of the outstanding loan using the effective interest method. The discount was fully amortized as of December 1, 2011. During fiscal years 2012 and 2011, we amortized $12,000 and $113,000, respectively, in non-cash interest expense, which amounts are included in interest and other expense in the accompanying consolidated financial statements. As of April 30, 2013, 101,523 warrants issued under this term loan were outstanding and exercisable (Note 8).

In connection with the term loan, we also incurred $469,000 in financing fees and legal costs related to the closing the term loan. These fees were classified as debt issuance costs and were amortized as a non-cash interest expense over the term of the outstanding loan using the effective interest method. The debt issuance costs were fully amortized as of December 1, 2011. During fiscal years 2012 and 2011, we amortized $21,000 and $122,000, respectively, in non-cash interest expense, which amounts are included in interest and other expense in the accompanying consolidated financial statements.

Capital Lease Obligations

We have financed certain equipment under capital lease agreements which bear interest at a rate ranging from 3.71% to 5.36% per annum.

The equipment purchased under these capital leases is included in property in the accompanying consolidated financial statements at April 30, 2013 and 2012, as follows:

	2013			2012
Furniture, fixtures, office equipment and software	$	258,000		$	258,000
Less accumulated depreciation and amortization		(148,000	)		(96,000	)
Net book value	$	110,000		$	162,000

Minimum future capital lease payments as of April 30, 2013 are as follows:

Year ending April 30,:
2014	$	34,000
2015		13,000
Total minimum lease payments		47,000
Amount representing interest		(2,000	)
Net present value minimum lease payments		45,000
Less current portion included in other current liabilities		(32,000	)
Long-term portion included in other long-term liabilities	$	13,000

4. COMMITMENTS AND CONTINGENCIES

12 Months Ended

Apr. 30, 2013

Commitments and Contingencies Disclosure [Abstract]

4. COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES

Operating Leases – Our corporate offices, research and development, and manufacturing facilities are located in Tustin, California. We lease an aggregate of approximately 61,000 square feet of office, research, and manufacturing space in three adjacent buildings under two separate lease agreements.

In December 1998, we entered into a lease agreement (the “Original Lease”) to lease two buildings located at our facilities in Tustin, California. The Original Lease has an original lease term of 12 years with two 5-year renewal options and includes scheduled rental increases of 3.35% every two years. In December 2005, we entered into a First Amendment to Lease and Agreement of Lease (“First Amendment”) with the landlord to our Original Lease and extended the original lease term for seven additional years to expire on December 31, 2017 while maintaining our two 5-year renewal options that could extend our lease to December 31, 2027. Our monthly lease payments will continue to increase at a rate of 3.35% every two years under the First Amendment.

In May 2010, we entered into a separate lease agreement to lease additional office and research space in a third building adjacent to our two existing leased buildings located in Tustin, California. Our monthly base rent under the lease agreement is approximately $11,000 and includes nominal scheduled increases every twelve months. The lease expires on December 31, 2017 and includes a 5-year option to extend the lease to December 31, 2022. In addition, under the terms of the lease agreement, we received a tenant improvement reimbursement of $125,000 during fiscal year 2011, which we classified as deferred rent and is being amortized on a straight-line basis over the term of the lease as a reduction to rent expense. Tenant improvements associated with the lease agreement are recorded as an addition to leasehold improvements and are being amortized over the shorter of the estimated useful life of the improvement or the remaining life of the lease.

Under each of the aforementioned facility operating leases, we record rent expense on a straight-line basis and the short-term and long-term differences between the amounts paid and the amounts expensed are included in other current liabilities and other long-term liabilities, respectively, in the accompanying consolidated financial statements. Annual rent expense under the aforementioned facility operating lease agreements totaled $938,000, $938,000, and $939,000 for the fiscal years ended April 30, 2013, 2012 and 2011, respectively.

At April 30, 2013, future minimum lease payments under all non-cancelable operating leases are as follows:

Year ending April 30,:		Minimum Lease Payments
	2014	$	1,072,000
	2015		1,079,000
	2016		1,079,000
	2017		1,068,000
	2018		730,000
		$	5,028,000

Legal Proceedings - In the ordinary course of business, we are at times subject to various legal proceedings and disputes. Except as set forth below, we currently are not aware of any material litigation or other dispute nor, to management’s knowledge, is any litigation or other proceeding threatened against us that collectively is expected to have a material adverse effect on our consolidated cash flows, financial condition or results of operations.

Securities Related Class Action Lawsuit

On September 28, 2012, three complaints were filed in the United States District Court for the Central District of California against us and certain of our executive officers and one consultant (collectively, the “Individual Defendants”) on behalf of certain purchasers of our common stock. The complaints have been brought as purported stockholder class actions, and, in general, include allegations that we and the Individual Defendants violated (i) Section 10(b) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and Rule 10b-5 promulgated thereunder and (ii) Section 20(a) of the Exchange Act, by making materially false and misleading statements regarding the interim median overall survival results of our bavituximab Phase II second-line NSCLC trial, thereby artificially inflating the price of our common stock. The plaintiffs are seeking unspecified monetary damages and other relief. On November 27, 2012, four prospective lead plaintiffs filed motions to consolidate, appoint a lead plaintiff, and appoint lead counsel. On February 5, 2013, the court appointed James T. Fahey as lead plaintiff in the action. The lead plaintiff filed an amended consolidated complaint on April 15, 2013. We filed a motion to dismiss the amended consolidated complaint on June 14, 2013. The lead plaintiff has until July 15, 2013, to file an answer to our motion to dismiss. A hearing before the Court on our motion to dismiss is scheduled for August 19, 2013. We believe that the class action lawsuit is without merit, and we intend to vigorously defend the action and are seeking dismissal of the complaint. Due to the early stage of the proceeding, we believe that the probability of an unfavorable outcome or loss related to the proceeding and an estimate of the amount or range of loss related to the claims, if any, from an unfavorable outcome is not determinable at this time.

Federal Shareholder Derivative Lawsuit

On May 9, 2013, an alleged shareholder filed in the United States District Court for the Central District of California a derivative lawsuit purportedly on behalf of the Company against certain of our executive officers and directors, captioned Michael Roy, Derivatively on Behalf of Nominal Defendant Peregrine Pharmaceuticals, Inc. v. Steven W. King, et al. The complaint asserts claims for breach of fiduciary duty, abuse of control, gross mismanagement, waste of corporate assets and unjust enrichment arising from substantially similar factual allegations as those contained in the consolidated securities class action described above. This case was subsequently transferred to the same court and judge handling the securities class action lawsuit discussed above. On May 31, 2013, the judge issued an order staying of this derivative litigation pending the resolution of our motion to dismiss in the securities class action.

Other Legal Matters

On September 24, 2012, we filed a lawsuit against Clinical Supplies Management, Inc. (“CSM”), in the United States District Court for the Central District of California. We had contracted with CSM in 2010 as our third party vendor responsible for distribution of the blinded investigational product used in our bavituximab Phase II second-line NSCLC trial. As part of the routine collection of data in advance of an end-of-Phase II meeting with regulatory authorities, we discovered major discrepancies between some patient sample test results and patient treatment code assignments. Consequently, we filed this lawsuit against CSM alleging breach of contract, negligence and negligence per se arising from CSM’s performance of its contracted services. We are seeking monetary damages. On March 7, 2013, we and CSM submitted to the court a proposed stipulation pursuant to which the lawsuit would be stayed for up to 120 days during which time we and CSM would participate in an alternative dispute resolution process, pursuant to our contract with CSM. The proposed stipulation was approved by the court on March 8, 2013. On June 26, 2013, we and CSM engaged in an alternative dispute resolution session that did not result in any resolution of our dispute. The aforementioned stay expired on July 6, 2013. We have agreed to allow CSM until July 19, 2013 to respond to our complaint.

5. LICENSE, RESEARCH AND DEVELOPMENT AGREEMENTS

12 Months Ended

Apr. 30, 2013

License Research And Development Agreements

5. LICENSE, RESEARCH AND DEVELOPMENT AGREEMENTS

LICENSE, RESEARCH AND DEVELOPMENT AGREEMENTS

The following represents a summary of our key collaborations for the development and commercialization of our products in clinical development covering bavituximab, 124I-PGN650 (“PGN650”), and Cotara. In addition, we do not perform any research and development activities for any unrelated entities.

Bavituximab

In August 2001 and August 2005, we exclusively in-licensed the worldwide rights to the phosphatidyserine (“PS”) targeting technology platform from the University of Texas Southwestern Medical Center at Dallas (“UTSWMC”), including bavituximab. During November 2003, we entered into a non-exclusive license agreement with Genentech, Inc., to license certain intellectual property rights covering methods and processes for producing antibodies used in connection with the development of our PS-targeting program. During December 2003, we entered into an exclusive commercial license agreement with Avanir Pharmaceuticals, Inc., (“Avanir”) covering the generation of a chimeric monoclonal antibody. In March 2005, we entered into a worldwide non-exclusive license agreement with Lonza Biologics (“Lonza”) for intellectual property and materials relating to the expression of recombinant monoclonal antibodies for use in the manufacture of bavituximab.

Under our in-licensing agreements relating to bavituximab, we typically pay an up-front license fee, annual maintenance fees, and are obligated to pay future milestone payments based on potential clinical development and regulatory milestones, plus a royalty on net sales and/or a percentage of sublicense income. The applicable royalty rate under each of the foregoing in-licensing agreements is in the low single digits. During fiscal year 2011, we expensed $114,000 associated with milestone obligations under in-licensing agreements covering bavituximab, which is included in research and development expense in the accompanying consolidated statements of operations and comprehensive loss. We did not incur any milestone related expenses during fiscal years 2013 and 2012.

The following table provides certain information with respect to each of our in-licensing agreements relating to our bavituximab program.

Licensor	Agreement Date	Total Milestone Obligations Expensed To Date		Potential Future Milestone Obligations ⁽¹⁾
UTSWMC	August 2001	$	98,000	$	375,000
UTSWMC	August 2005		85,000		375,000
Lonza	March 2005		64,000		–(2	)
Avanir	December 2003		50,000		1,050,000
Genentech, Inc.	November 2003		500,000		5,000,000
Total		$	797,000	$	6,800,000

______________

(1)

Potential future milestone obligations are generally tied to regulatory progress to gain product approval, which approval significantly depends on positive clinical trials results. In addition, potential future milestone obligations vary by license agreement (as defined in each license agreement) and depend on valid claims under each of these underlying agreements at the time the potential milestone is achieved, however, the following clinical development and regulatory milestones are typical of such potential future milestone events: upon dosing of first patient in a Phase I, Phase II, and/or Phase III clinical trial; completion of patient enrollment in a phase II trial; submission of a biologics license application in the U.S.; and upon FDA approval.

(2)

In fiscal year 2011, we incurred a milestone fee of 37,500 pounds sterling ($64,000 U.S.) upon commencement of patient enrollment in our first randomized phase II clinical trial using bavituximab, which amount would continue as an annual license fee thereafter until completion of patient enrollment, at which time the annual license fee would increase to 75,000 pounds sterling per annum. During fiscal year 2012, we completed patient enrollment of the aforementioned phase II clinical trial, which triggered the annual license fee to increase to 75,000 pounds sterling per annum (or approximately $116,000 U.S. based on the exchange rate at April 30, 2013). In addition, in the event we utilize an outside contract manufacturer other than Lonza to manufacture bavituximab for commercial purposes, we would owe Lonza 300,000 pounds sterling per year (or approximately $465,000 U.S. based on the exchange rate at April 30, 2013).

Of the total potential future milestone obligation of $6,800,000, we anticipate milestone obligations not to exceed $200,000 during fiscal year 2014. In addition, of the total potential future milestone obligations of $6,800,000, up to $6,400,000 would be due upon the first commercial approval of bavituximab pursuant to these license agreements. However, given the uncertainty of the drug development and the regulatory approval process, we are unable to predict with any certainty when any of these milestones will occur, if at all.

PGN650

In October 1998, we exclusively in-licensed worldwide rights from UTSWMC, to certain patent families, which was amended in January 2000 to license patents related to aminophospholipid targeting conjugates, such as PGN650. Under the October 1998 license agreement, as amended, we are obligated to pay UTSWMC future milestone payments of up to $300,000 for PGN650 based on the achievement of certain potential clinical development and commercial milestones, plus a low single digit royalty on net sales.

In addition, during fiscal year 2007, we entered into a research collaboration agreement and a development and commercialization agreement with Affitech A/S (as further discussed below under “Other Licenses Covering Products in Development”) regarding the generation and commercialization of a certain number of fully human monoclonal antibodies under our platform technologies to be used as possible future clinical candidates, including our imaging agent PGN650. During fiscal year 2013, we elected to enter into a license agreement for the PS-targeting antibody used to create PGN650 and agreed to pay an up-front license fee and are obligated to pay future milestone payments of up to $1,921,000 based on the achievement of certain potential clinical development and regulatory milestones, plus a low single digit royalty on net sales.

During fiscal year 2013, we expensed $50,000 under in-licensing agreements covering PGN650, which is included in research and development expense in the accompanying consolidated statements of operations and comprehensive loss. We did not incur any milestone related expenses during fiscal years 2012 or 2011 covering PGN650. In addition, no product revenues have been generated from PGN650 program to date. We anticipate milestone obligations for PGN650 under this agreement not to exceed $51,000 during fiscal year 2014.

Cotara

We acquired the patent rights to Cotara in July 1994 after the merger between Peregrine and Cancer Biologics, Inc. was approved by our stockholders. To date, no product revenues have been generated from Cotara.

In October 2004, we entered into a worldwide non-exclusive license agreement with Lonza for intellectual property and materials relating to the expression of recombinant monoclonal antibodies for use in the manufacture of Cotara. Under the terms of the agreement, we are obligated to pay a royalty (in the low single digits) on net sales of any products we market that utilize the underlying technology. In the event a product is approved and we or Lonza do not manufacture Cotara, we would owe Lonza 300,000 pounds sterling per year (or approximately $465,000 U.S. based on the exchange rate at April 30, 2013) in addition to an increased royalty (in the low single digits) on net sales. In addition, upon completion of patient enrollment in our Cotara Phase II clinical trial during fiscal year 2011, we incurred a milestone payment of 75,000 pounds sterling (or $125,000 U.S.), which amount will continue as an annual license fee thereafter. Unless sooner terminated due to a party’s breach of the license agreement, the license agreement with Lonza will terminate upon the last to occur of the expiration of a period of 15 years following our first commercial sale of a product or the expiration of the last valid claim within the patents that are the subject of the license agreement; provided that if after the expiration of the last claim but prior to the expiration of the 15-year period, Lonza has publicly made available certain materials and know-how, then the agreement will terminate at such time as the materials and know-how are made public.

Other Licenses Covering Products in Development

During August 2001, we entered into an exclusive worldwide license agreement for an anti-VEGF compound from the UTSWMC. During July 2009, we entered into a patent assignment and sublicense with Affitech A/S whereby we licensed exclusive worldwide rights to develop and commercialize certain products under our anti-VEGF intellectual property portfolio as further described in the “Out-Licensing Collaborations” section below. Under the UTSWMC license agreement, we paid an up-front license fee and are obligated to pay annual maintenance fees, and future milestone payments based on certain potential clinical development and regulatory milestones, plus a royalty on net sales. Our aggregate future milestone payments under this exclusive worldwide license are $450,000 assuming the achievement of all development milestones under the agreement through commercialization of the product. We do not anticipate making any milestone payments for at least the next fiscal year under the UTSWMC license agreement.

During fiscal year 2007, we entered into a research collaboration agreement and a development and commercialization agreement with Affitech A/S regarding the generation and commercialization of a certain number of fully human monoclonal antibodies under our platform technologies to be used as possible future clinical candidates, including our lead imaging agent PGN650. These agreements also incorporate a binding term sheet we entered into with Affitech A/S in September 2010. Under the terms of the development and commercialization agreement, if we elect to enter into a license agreement for a clinical candidate, we are obligated to pay future milestone payments based on the achievement of certain potential clinical development and regulatory milestones, plus a low single digit royalty on net sales. Our potential aggregate future milestone payments range from $1,971,000 to $2,975,000 per fully human antibody generated by the unrelated entity upon the achievement of certain development milestones through commercialization. In addition, under the terms of the research collaboration agreement, we paid a research fee for each human antibody project initiated. During fiscal year 2013, we elected to enter into a license agreement for one clinical candidate as further discussed under “PGN650”. During fiscal year 2011, we expensed $956,000 under the research collaboration agreement, the amount of which is included in research and development expense in the accompanying consolidated financial statements. We did not incur any additional expenses under the research collaboration agreement during fiscal years 2013 and 2012. We do not expect to incur any additional license fees or milestone payments under these agreements during fiscal year 2014 except as mentioned above under “PGN650”.

Out-Licensing Collaborations

In addition to our in-licensing collaborations, the following represents a summary of our key out-licensing collaborations.

During October 2000, we entered into a licensing agreement with Merck KGaA to out-license a segment of our Cotara technology for use in the application of cytokine fusion proteins. During January 2003, we entered into an amendment to the license agreement, whereby we received an extension to the royalty period from six years to ten years from the date of the first commercial sale. Under the terms of the agreement, we would receive a royalty on net sales if a product is approved under the agreement. Merck KGaA is currently in the clinical development stage of this program.

During July 2009, we entered into a patent assignment and sublicense (collectively, the “Affitech Agreements”) with Affitech A/S (“Affitech”) whereby we licensed exclusive worldwide rights to develop and commercialize certain products under our anti-VEGF intellectual property portfolio, including the fully human antibody AT001/r84. In consideration for the rights granted under our anti-VEGF antibody technology platform, we received non-refundable up-front license fees of $250,000. In addition, we received aggregate milestone payments of $1,000,000 associated with the delivery of two preclinical development packages as defined in the Affitech Agreements. We could also receive up to $16,500,000 in future milestone payments based on the achievement of all clinical and regulatory milestones for product approval by Affitech or an affiliate, plus a royalty on net sales, as defined in the Affitech Agreements. These potential future milestone payments payable under the Affitech Agreements entail no performance obligations on our part and, accordingly, these payments will not be accounted for under the provisions of ASU No. 2010-17. Therefore, we expect to recognize revenue on the future potential milestone payments in accordance with the authoritative guidance for revenue recognition, either when the milestone is achieved, if our future obligations are considered inconsequential, or recognized as revenue on a straight-line basis over a performance obligation period, if continued performance or future obligations exist. To date, no clinical or regulatory milestones as defined in the Affitech Agreements have been achieved by Affitech or an affiliate. In addition, in the event Affitech enters into a sublicense agreement with a non-affiliate for the anti-VEGF technology platform, we shall receive a percentage of all payments received under any such sublicenses, which percentage is determined based on the clinical development stage of the technology platform at the time of any such sublicenses. Under the Affitech Agreements, we also granted Affitech a research license in the ocular field with an option to grant sub-licenses in the ocular field. If Affitech exercises this option to grant sublicenses in the ocular field, we could receive pre-defined up-front fees, milestone payments, and a royalty on net sales. In accordance with the authoritative guidance for revenue recognition, the license includes multiple elements that are not separable and, accordingly, are being accounted for as a single unit of accounting. In addition, we determined that our obligations would be up to a four-year period and therefore, we are recognizing the non-refundable up-front license fees of $250,000 and the additional $1,000,000 associated with other deliverables, as defined in the Affitech Agreements, on a straight-line basis over a four-year period ending July 2013. We recognized revenue of $350,000 during fiscal years 2013, 2012, and 2011 under the Affitech Agreements, which amounts are included in license revenue in the accompanying consolidated financial statements. Amounts received prior to satisfying our revenue recognition criteria are recorded as deferred revenue in the accompanying consolidated financial statements.

During September 2010, Peregrine and Affitech amended certain terms of the Affitech Agreements for sublicenses entered into by Affitech with non-affiliates for the territories of Brazil, Russia and other countries of the Commonwealth of Independent States (“CIS”) (“September 2010 Amendment”). Under the amended terms, Peregrine agreed to forego its aforementioned sublicense fee equal to forty-five percent (45%) of the payments received by Affitech (after Affitech deducts fifty percent (50%) of its incurred development costs under the program) for the territories of Brazil, Russia, and the CIS, provided however, that Affitech reinvests such sublicense payments toward the further development of AT001/r84 in those territories. In the event Affitech enters into a licensing transaction for AT001/r84 with a non-affiliate in a major pharmaceutical market (defined as U.S., European Union, Switzerland, United Kingdom and/or Japan), Affitech has agreed to reimburse us the aforementioned sublicense fees we agreed to forego that were applied to the AT001/r84 program while Affitech will be eligible to be reimbursed for up to 50% of their development costs in Brazil, Russia and CIS territories. The remaining terms of the Affitech Agreements remain unchanged, including milestone and royalty payments. To date, we have not received any payments from Affitech under the September 2010 Amendment.

6. STOCKHOLDERS' EQUITY

12 Months Ended

Apr. 30, 2013

Equity [Abstract]

6. STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY

Adoption of a Stockholder Rights Agreement

On March 16, 2006, our Board of Directors adopted a Stockholder Rights Agreement (“Rights Agreement”) that is designed to strengthen the ability of the Board of Directors to protect the interests of our stockholders against potential abusive or coercive takeover tactics and to enable all stockholders the full and fair value of their investment in the event that an unsolicited attempt is made to acquire Peregrine. The adoption of the Rights Agreement is not intended to prevent an offer the Board of Directors concludes is in the best interest of Peregrine and its stockholders.

Under the Rights Agreement, the Board of Directors declared a dividend of one preferred share purchase right (a “Right”) for each share of our common stock held by shareholders of record as of the close of business on March 27, 2006. Each Right will entitle holders of each share of our common stock to buy one thousandth (1/1,000th) of a share of Peregrine’s Series D Participating Preferred Stock, par value $0.001 per share, at an exercise price of $11.00 per share, subject to adjustment. The Rights are neither exercisable nor traded separately from our common stock. The Rights will become exercisable and will detach from the common shares if a person or group acquires 15% or more of our outstanding common stock, without prior approval from our Board of Directors, or announces a tender or exchange offer that would result in that person or group owning 15% or more of our common stock. Each Right, when exercised, entitles the holder (other than the acquiring person or group) to receive common stock of the Company (or in certain circumstances, voting securities of the acquiring person or group) with a value of twice the Rights’ exercise price upon payment of the exercise price of the Rights.

Peregrine will be entitled to redeem the Rights at $0.001 per Right at any time prior to a person or group achieving the 15% threshold. The Rights will expire on March 16, 2016.

Sales of Common Stock

Our ability to continue our clinical trials and development efforts is highly dependent on the amount of cash and cash equivalents on hand combined with our ability to raise additional capital to support our future operations through one or more methods, including but not limited to, issuing additional equity.

With respect to financing our operations through the issuance of equity, we have raised additional capital during the three fiscal years ended April 30, 2013, under the following financing agreements:

July 2009 AMI Agreement – On July 14, 2009, we entered into an At Market Sales Issuance Agreement (“July 2009 AMI Agreement”) with Wm Smith & Co., pursuant to which, through Wm Smith & Co., as agent, we were able to sell shares of our common stock, from time to time at market prices, for aggregate gross proceeds of up to $25,000,000, in registered transactions from our shelf registration statement on Form S-3 (File No. 333-160572), filed with the Securities and Exchange Commission “(SEC”) on July 14, 2009 (“July 2009 Shelf”). During fiscal year 2011, we had sold 1,925,565 shares of common stock at market prices under the July 2009 AMI Agreement for aggregate gross proceeds of $5,568,000 before deducting commissions and other issuance costs of $133,000. As of April 30, 2011, we had raised the entire $25,000,000 available under the July 2009 AMI Agreement.

June 2010 AMI Agreement – On June 22, 2010, we entered into an At Market Sales Issuance Agreement (“June 2010 AMI Agreement”) with McNicoll, Lewis & Vlak LLC (now known as MLV & Co. LLC, “MLV”), pursuant to which, through MLV, as agent, we were able to sell shares of our common stock, from time to time at market prices, for aggregate gross proceeds of up to $15,000,000 in registered transactions from our July 2009 Shelf. During fiscal year 2011, we had sold 9,214,373 shares of common stock at market prices under the June 2010 AMI Agreement for aggregate gross proceeds of $15,000,000 before deducting commissions and other issuance costs of $345,000.

December 2010 AMI Agreement – On December 29, 2010, we entered into an At Market Sales Issuance Agreement (“December 2010 AMI Agreement”) with MLV, pursuant to which, through MLV, as agent, we were able to sell shares of our common stock, from time to time at market prices, in registered transactions from our shelf registration statement on Form S-3 (File No. 333-171252) filed with the SEC on December 29, 2010 (“December 2010 Shelf”), for aggregate gross proceeds of up to $75,000,000. During fiscal year 2011, we sold 5,224,491 shares of common stock at market prices under the December 2010 AMI Agreement for aggregate gross proceeds of $13,288,000 before deducting commissions and other issuance costs of $291,000. During fiscal year 2012, we sold 24,873,930 shares of common stock at market prices under the December 2010 AMI Agreement for aggregate gross proceeds of $27,390,000 before deducting commissions and other issuance costs of $626,000. During fiscal year 2013, we sold 31,863,368 shares of common stock at market prices under the December 2010 AMI Agreement for aggregate gross proceeds of $27,382,000 before deducting commissions and other issuance costs of $895,000. As of April 30, 2013, we had raised the full amount of gross proceeds available to us under the December 2010 AMI Agreement.

September 2011 Registered Direct Public Offering – Under a registered direct public offering dated September 2, 2011, we entered into separate subscription agreements with three institutional investors, pursuant to which we sold an aggregate of 6,252,252 shares of our common stock at a purchase price of $1.11 per share for aggregate gross proceeds of $6,940,000 before deducting placement agent fees and other offering expenses of $525,000. The shares of common stock sold in connection with this offering were issued to a prospectus supplement filed the SEC on September 2, 2011 to our December 2010 Shelf.

December 2012 AMI Agreement – On December 27, 2012, we entered into an At Market Sales Issuance Agreement (“December 2012 AMI Agreement”) with MLV, pursuant to which we may sell shares of our common stock through MLV, as agent, for aggregate gross proceeds of up to $75,000,000, in registered transactions from our shelf registration statement on Form S-3 (File No. 333-180028), filed with the SEC on March 9, 2012. During fiscal year 2013, we sold 9,320,675 shares of common stock at market prices under the December 2012 AMI Agreement for aggregate gross proceeds of $13,372,000 before deducting commissions and other issuance costs of $337,000. As of April 30, 2013, aggregate gross proceeds of up to $61,628,000 remained available under the December 2012 AMI Agreement.

Subsequent to April 30, 2013 and through July 11, 2013, we sold 7,927,016 shares of common stock at market prices under the December 2012 AMI Agreement for aggregate gross proceeds of $12,729,000. As of July 11, 2013, aggregate gross proceeds of $48,899,000 remained available under the December 2012 AMI Agreement.

Shares Of Common Stock Authorized And Reserved For Future Issuance

As of April 30, 2013, we had reserved 23,895,316 additional shares of our common stock, which may be issued under our equity compensation plans and outstanding warrant agreements, excluding shares of common stock that could potentially be issued under our current effective shelf registration statement, as further described in the following table:

	Number of Shares Reserved
Common shares reserved for issuance under outstanding option grants and common shares available for issuance under our stock incentive plans		20,081,954
Common shares reserved for and available for issuance under our Employee Stock Purchase Plan		3,438,559
Common shares issuable upon exercise of outstanding warrants		374,803
Total shares of common stock reserved for issuance		23,895,316

7. EQUITY COMPENSATION PLANS

12 Months Ended

Apr. 30, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

7. EQUITY COMPENSATION PLANS

EQUITY COMPENSATION PLANS

Stock Incentive Plans

We currently maintain seven stock incentive plans referred to as the 2011 Plan, the 2010 Plan, the 2009 Plan, the 2005 Plan, the 2003 Plan, the 2002 Plan, and the 1996 Plan (collectively referred to as the “Stock Plans”). The 2011, 2010, 2009, 2005, 2003 and 1996 Plans were approved by our stockholders while the 2002 Plan was not submitted for stockholder approval. The Stock Plans provide for the granting of stock options, restricted stock awards and other forms of share-based awards to purchase shares of our common stock at exercise prices not less than the fair market value of our common stock at the date of grant.

As of April 30, 2013, we had an aggregate of 20,081,954 shares of common stock reserved for issuance under the Stock Plans. Of those shares, 15,287,208 shares were subject to outstanding options and 4,794,746 shares were available for future grants of share-based awards.

Stock Options – Stock options granted under our Stock Plans are granted at an exercise price not less than the fair market value of our common stock on the date of grant. The options generally vest over a two to four year period and expire ten years from the date of grant, if unexercised. However, certain option awards provide for accelerated vesting if there is a change in control (as defined in the Stock Plans).

The fair value of each option grant is estimated using the Black-Scholes option valuation model and is amortized as compensation expense on a straight-line basis over the requisite service period of the award, which is generally the vesting period. The use of a valuation model requires us to make certain estimates and assumptions with respect to selected model inputs. The expected volatility is based on the daily historical volatility of our common stock covering the estimated expected term. The expected term of options granted reflects actual historical exercise activity and assumptions regarding future exercise activity of unexercised, outstanding options. The risk-free interest rate is based on U.S. Treasury notes with terms within the contractual life of the option at the time of grant. The expected dividend yield assumption is based on our expectation of future dividend payouts. We have never declared or paid any cash dividends on our common stock and currently do not anticipate paying such cash dividends. In addition, guidance requires forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. The fair value of stock options on the date of grant and the weighted-average assumptions used to estimate the fair value of the stock options using the Black-Scholes option valuation model for fiscal years ended April 30, 2013, 2012 and 2011, were as follows:

	Year Ended April 30,
	2013	2012	2011
Risk-free interest rate	0.96%	1.44%	2.09%
Expected life (in years)	5.85	5.92	6.00
Expected volatility	95.87%	74.08%	73.42%
Expected dividend yield	-	-	-

The following summarizes our stock option transaction activity for fiscal year ended April 30, 2013:

Stock Options	Shares			Weighted Average Exercisable Price		Weighted Average Remaining Contractual Term (years)		Aggregate Intrinsic Value ⁽¹⁾
Outstanding, May 1, 2012		7,531,651		$	2.90
Granted		8,677,208		$	0.88
Exercised		(118,555	)	$	0.83
Canceled or expired		(803,096	)	$	1.58
Outstanding, April 30, 2013		15,287,208		$	1.84		8.07	$	5,294,000

Exercisable and expected to vest		15,086,905		$	1.85		8.05	$	5,228,000
Exercisable, April 30, 2013		7,434,607		$	2.67		6.86	$	1,811,000

⁽²⁾

Aggregate intrinsic value represents the difference between the exercise price of an option and the closing market price of our common stock on April 30, 2013, which was $1.39 per share.

The weighted-average grant date fair value of options granted to employees during the fiscal years ended April 30, 2013, 2012 and 2011 was $0.69, $0.99 and $1.31 per share, respectively.

The aggregate intrinsic value of stock options exercised during the fiscal years ended April 30, 2013 and 2011 was $106,000 and $5,000, respectively. Cash received from stock options exercised, net of issuance costs, during the fiscal years ended April 30, 2013 and 2011 totaled $96,000 and $44,000, respectively. No stock options were exercised during fiscal year ended April 30, 2012.

We issue shares of common stock that are reserved for issuance under the Stock Plans upon the exercise of stock options, and we do not expect to repurchase shares of common stock from any source to satisfy our obligations under our compensation plans.

As of April 30, 2013, the total estimated unrecognized compensation cost related to non-vested stock options was $5,119,000. This cost is expected to be recognized over a weighted average vesting period of 1.47 years based on current assumptions.

Restricted Stock Awards – Restricted stock awards are grants that entitle the holder to shares of common stock subject to certain terms. The fair value of restricted stock awards is the quoted market price of our stock on the grant date, and is charged to expense over the period of vesting. Restricted stock awards associated with non-performance conditions vest over the requisite service period and restricted stock awards associated with performance conditions are subject to vesting upon completion of the underlying performance condition. Performance based restricted stock awards are subject to forfeiture if the underlying performance condition is not achieved and all restricted stock awards are subject to forfeiture to the extent that the recipient’s service is terminated prior to the awards becoming vested.

No restricted stock awards were granted or vested during fiscal years ended April 30, 2013 and 2012. As of April 30, 2013, there was no unrecognized compensation cost related to unvested restricted stock awards.

During fiscal year ended April 30, 2011, the weighted-average grant date fair value of restricted stock awards granted was $2.37 and the total fair value of restricted stock awards vested was $404,000.

Employee Stock Purchase Plan

On October 21, 2010, our stockholders approved our 2010 Employee Stock Purchase Plan (the “2010 ESPP”). The 2010 ESPP allows eligible employees on a voluntary basis to purchase shares of our common stock directly from the Company. Under the 2010 ESPP, we will sell shares to participants at a price equal to the lesser of 85% of the fair market value of stock at the (i) beginning of a six-month offering period or (ii) end of the six-month offering period. The 2010 ESPP provides for two six-month offering periods each fiscal year; the first offering period will begin on the first trading day on or after each November 1; the second offering period will begin on the first trading day on or after each May 1.

A total of 5,000,000 shares are reserved for issuance under the 2010 ESPP, of which 3,438,559 shares remained available to purchase at April 30, 2013 and are subject to adjustment as provided in the 2010 ESPP for stock splits, stock dividends, recapitalizations and other similar events. During the fiscal years ended April 30, 2013, 2012 and 2011, 998,556, 458,041 and 104,844 shares of common stock were purchased, respectively, under the 2010 ESPP at a weighted average purchase price per share of $0.53, $0.52 and $1.28, respectively.

The fair value of the shares purchased under the 2010 ESPP were determined using a Black-Scholes option pricing model (see explanation of valuation model inputs above under “Stock Options”), and is recognized as expense on a straight-line basis over the requisite service period (or six-month offering period). The weighted average grant date fair value of purchase rights under the 2010 ESPP during fiscal years ended April 30, 2013, 2012 and 2011 was $0.40, $0.46 and $0.52, respectively, based on the following Black-Scholes option valuation model inputs:

	Year Ended April 30,
	2013	2012	2011
Risk-free interest rate	0.15%	0.06%	0.15%
Expected life (in years)	0.50	0.50	0.50
Expected volatility	167.36%	67.96%	82.72%
Expected dividend yield	-	-	-

Share-based Compensation Expense

Total share-based compensation expense related to share-based awards issued under our equity compensation plans for the fiscal years ended April 30, 2013, 2012 and 2011 was comprised of the following:

	2013		2012		2011
Cost of contract manufacturing	$	89,000	$	12,000	$	8,000
Research and development		1,646,000		1,018,000		1,134,000
Selling, general and administrative		1,700,000		1,739,000		1,695,000
Total share-based compensation expense	$	3,435,000	$	2,769,000	$	2,837,000

Share-based compensation from:
Stock options	$	3,039,000	$	2,673,000	$	2,598,000
Restricted stock awards		–		–		185,000
Employee stock purchase plan		396,000		96,000		54,000
	$	3,435,000	$	2,769,000	$	2,837,000

The cost of non-employee services received in exchange for share-based awards are measured based on either the fair value of the consideration received or the fair value of the share-based award issued, whichever is more reliably measurable. In addition, the authoritative guidance requires share-based compensation related to unvested options and awards issued to non-employees to be recalculated at the end of each reporting period based upon the fair market value on that date until the share-based award has vested, and any adjustment to share-based compensation resulting from the re-measurement is recognized in the current period. Share-based compensation expense recorded during fiscal years ended April 30, 2013, 2012 and 2011 associated with stock options and awards granted to non-employees amounted to $320,000, $51,000 and $114,000, respectively.

Due to our net loss position, no tax benefits have been recognized in the consolidated statements of cash flows.

8. WARRANTS

12 Months Ended

Apr. 30, 2013

Warrants and Rights Note Disclosure [Abstract]

8. WARRANTS

WARRANTS

As of April 30, 2013, the following warrants to purchase an aggregate of 374,803 shares of our common stock were outstanding:

Date Issued	Warrants Outstanding		Exercise Price Per Share		Expiration Date
December 19, 2008 (Note 3)		101,523	$	1.4775	December 19, 2013
August 30, 2012 (Note 3)		273,280	$	2.4700	August 30, 2018
Total Warrants Outstanding		374,803

During fiscal years 2013 and 2011, 118,444 and 118,443 warrants were exercised on a cashless basis, respectively, in exchange for 46,427 and 74,802 shares of our common stock, respectively. These warrants were issued in December 2008 in connection with a three-year term loan we entered into during fiscal year 2009, which was paid in full during December 2011 (Note 3). There were no warrants exercised during fiscal year 2012.

9. INCOME TAXES

12 Months Ended

Apr. 30, 2013

Income Tax Disclosure [Abstract]

9. INCOME TAXES

INCOME TAXES

We are primarily subject to U.S. federal and California state jurisdictions. To our knowledge, all tax years remain open to examination by U.S. federal and state authorities.

In addition, in accordance with authoritative guidance, we are required to recognize the impact of an uncertain tax position in the consolidated financial statements when it is more likely than not the position will be sustained upon examination by the tax authorities. An uncertain tax position will not be recognized if it has less than a 50% likelihood of being sustained upon examination by the tax authorities. We had no unrecognized tax benefits from uncertain tax positions as of April 30, 2013 and 2012. It is also our policy, in accordance with authoritative guidance, to recognize interest and penalties related to income tax matters in interest and other expense in our consolidated statements of operations. We did not recognize interest or penalties related to income taxes for fiscal years ended April 30, 2013, 2012, and 2011, and we did not accrue for interest or penalties as of April 30, 2013 and 2012.

At April 30, 2013, we had total deferred tax assets of $114,839,000. Due to uncertainties surrounding our ability to generate future taxable income to realize these tax assets, a full valuation has been established to offset our total deferred tax assets. Additionally, the future utilization of our net operating loss carry forwards to offset future taxable income may be subject to an annual limitation, pursuant to Internal Revenue Code Section 382, as a result of ownership changes that may have occurred previously or that could occur in the future. During the fiscal year ended April 30, 2013, a Section 382 analysis was performed and it was determined that no change in ownership had occurred. As such, we have included in our deferred tax assets all of the net operating loss carry forwards and have recorded a corresponding increase to our valuation allowance.

At April 30, 2013, we had federal net operating loss carry forwards of approximately $266,174,000. The net operating loss carry forwards expire in fiscal years 2019 through 2033. We also have state net operating loss carry forwards of approximately $203,167,000 at April 30, 2013, which begin to expire in fiscal year 2014. Included in these tax loss carry forwards are share-based compensation deductions in the amount of $5,722,000 that, when fully utilized, reduce cash income taxes and will result in a financial statement income tax benefit. The future income tax benefit, if realized, will be recorded to additional paid-in capital.

The provision for income taxes consists of the following for the three years ended April 30,:

	2013			2012			2011
Provision for federal income taxes at statutory rate	$	(10,125,000	)	$	(14,321,000	)	$	(11,611,000	)
State income taxes, net of federal benefit		2,000			20,000			(406,000	)
Expiration and adjustment of loss carry forwards		(98,263,000	)		13,980,000			9,174,000
Change in valuation allowance		108,310,000			(95,000	)		2,294,000
Other, net		76,000			416,000			549,000
Income tax (expense) benefit	$	–		$	–		$	–

Deferred income taxes reflect the net effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts for income tax purposes. Significant components of our deferred tax assets at April 30, are as follows:

	2013			2012

Share-based compensation	$	4,624,000		$	3,494,000
Deferred revenue		1,912,000			1,719,000
Depreciation and amortization		668,000			623,000
Accrued liabilities		1,677,000			693,000
Net operating losses		105,958,000			–

Total deferred tax assets		114,839,000			6,529,000
Less valuation allowance		(114,839,000	)		(6,529,000	)

Net deferred tax assets	$	–		$	–

10. BENEFIT PLAN

12 Months Ended

Apr. 30, 2013

Compensation and Retirement Disclosure [Abstract]

10. BENEFIT PLAN

10.

BENEFIT PLAN

During fiscal year 1997, we adopted a 401(k) benefit plan (the “Plan”) for all full-time employees who are at least the age of 21 and have three or more months of continuous service. The Plan provides for employee contributions of up to 100% of their compensation on a tax deferred basis up to the maximum amount permitted by the Internal Revenue Code. We are not required to make matching contributions under the Plan and we have made no matching contributions to the Plan since its inception through December 2009. Effective January 2010, we voluntarily agreed to match 50% of employee contributions of up to the first 6% of a participant’s annual salary for all Plan contributions, subject to certain IRS limitations. Under the Plan, each participating employee is fully vested in his or her contributions to the Plan and our contributions to the Plan will fully vest after six years of service. The expense related to our matching contributions to the Plan was $284,000, $232,000 and $210,000 for the fiscal years ended April 30, 2013, 2012 and 2011, respectively.

11. SEGMENT REPORTING

12 Months Ended

Apr. 30, 2013

Segment Reporting [Abstract]

11. SEGMENT REPORTING

11.

SEGMENT REPORTING

Our business is organized into two reportable operating segments and both operate in the U.S. Peregrine is engaged in the research and development of monoclonal antibodies for the treatment and diagnosis of cancer. Avid is engaged in providing contract manufacturing services for Peregrine and third-party customers on a fee-for-service basis.

The accounting policies of the operating segments are the same as those described in Note 2. We evaluate the performance of our contract manufacturing services segment based on gross profit or loss from third-party customers. However, our products in the research and development segment are not evaluated based on gross profit or loss, but rather based on scientific progress of the technologies. As such, gross profit or loss is only provided for our contract manufacturing services segment in the below table. All revenues shown below are derived from transactions with third-party customers.

Segment information is summarized as follows:

	2013			2012			2011
Contract manufacturing services revenue	$	21,333,000		$	14,783,000		$	8,502,000
Cost of contract manufacturing services		12,595,000			10,153,000			7,296,000
Gross profit	$	8,738,000		$	4,630,000		$	1,206,000
Revenue from products in research and development	$	350,000		$	450,000		$	4,990,000
Research and development expense		(24,306,000	)		(35,688,000	)		(29,462,000	)
Selling, general and administrative expense		(13,134,000	)		(11,462,000	)		(11,421,000	)
Other income (expense), net		268,000			(49,000	)		536,000
Loss on early extinguishment of debt		(1,696,000	)		–			–
Net loss	$	(29,780,000	)	$	(42,119,000	)	$	(34,151,000	)

Revenue generated from our contract manufacturing services segment was derived from a limited number of customers. The percentages below represent revenue derived from each customer as a percentage of total contract manufacturing services revenue:

	2013	2012	2011
United States (customer A)	81%	44%	56%
United States (customer B)	17	-	-
Germany (one customer)	-	17	24
Denmark (one customer)	-	25	19
Other customers	2	14	1
Total	100%	100%	100%

Revenue generated from our products in our research and development segment was derived from the following sources:

	2013		2012		2011
Government contract revenue¹ (see Note 2)	$	–	$	–	$	4,640,000
License revenue		350,000		450,000		350,000
Total	$	350,000	$	450,000	$	4,990,000

⁽¹⁾

Represents revenue earned under a former government contract with the TMT of the U.S. Department of Defense’s Defense Threat Reduction Agency, which expired on April 15, 2011.

Our long-lived assets consist of leasehold improvements, laboratory equipment, and furniture, fixtures, office equipment and software and are net of accumulated depreciation. Long-lived assets by segment consist of the following:

	2013		2012
Long-lived Assets, net:
Contract manufacturing services	$	2,039,000	$	2,080,000
Products in research and development		639,000		820,000
Total	$	2,678,000	$	2,900,000

12. SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)

12 Months Ended

Apr. 30, 2013

Quarterly Financial Information Disclosure [Abstract]

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)

12.

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)

Selected quarterly financial information for each of the two most recent fiscal years is as follows:

	Quarter Ended
	April 30,			January 31,			October 31,			July 31,			April 30,			January 31,			October 31,			July 31,
	2013			2013			2012			2012			2012			2012			2011			2011
Net revenues	$	4,254,000		$	7,039,000		$	6,139,000		$	4,251,000		$	2,065,000		$	3,281,000		$	4,242,000		$	5,655,000
Gross profit (a)	$	959,000		$	3,310,000		$	2,358,000		$	2,111,000		$	1,053,000		$	719,000		$	436,000		$	2,422,000
Loss from operations...	$	(8,463,000	)	$	(5,161,000	)	$	(7,057,000	)	$	(7,671,000	)	$	(10,890,000	)	$	(11,093,000	)	$	(12,036,000	)	$	(8,051,000	)
Net loss (b)	$	(8,449,000	)	$	(4,914,000	)	$	(8,753,000	)	$	(7,664,000	)	$	(10,882,000	)	$	(11,090,000	)	$	(12,055,000	)	$	(8,092,000	)
Basic and diluted loss per common share	$	(0.06	)	$	(0.04	)	$	(0.08	)	$	(0.07	)	$	(0.10	)	$	(0.13	)	$	(0.16	)	$	(0.11	)

	(a)	Gross profit represents contract manufacturing revenue less cost of contract manufacturing.

	(b)	Net loss for the quarter ended October 31, 2012, included a loss on the early extinguishment of debt of $1,696,000 (Note 4).

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Apr. 30, 2013

Accounting Policies [Abstract]

Basis of Presentation

Use of Estimates

Liquidity and Financial Condition

Trade and Other Receivables

	2013		2012
Trade receivables⁽¹⁾	$	1,642,000	$	2,264,000
Other receivables, net		20,000		89,000
Trade and other receivables, net	$	1,662,000	$	2,353,000

⁽¹⁾Represents amounts billed for contract manufacturing services provided by Avid.

Allowance for Doubtful Accounts

Prepaid Research and Development Expenses

Inventories

Inventories - Inventories are stated at the lower of cost or market and primarily include raw materials, direct labor and overhead costs (work-in-process) associated with our wholly owned subsidiary, Avid. Cost is determined by the first-in, first-out method. Inventories consist of the following at April 30,

	2013		2012
Raw materials	$	2,169,000	$	1,966,000
Work-in-process		2,170,000		1,645,000
Total inventories	$	4,339,000	$	3,611,000

Property

Property - Property is recorded at cost. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the related asset, generally ranging from three to ten years. Amortization of leasehold improvements is calculated using the straight-line method over the shorter of the estimated useful life of the asset or the remaining lease term.

Concentrations of Credit Risk and Customer Base

Comprehensive Loss

Impairment

Impairment - Long-lived assets are reviewed for impairment in accordance with authoritative guidance for impairment or disposal of long-lived assets. Long-lived assets are reviewed for events or changes in circumstances, which indicate that their carrying value may not be recoverable. Long-lived assets are reported at the lower of carrying amount or fair value less cost to sell.

Fair Value of Financial Instruments

Fair Value Measurements

Level 1 – Quoted prices in active markets for identical assets or liabilities.

Level 3 – Unobservable inputs that are supported by little or no market activity and significant to the overall fair value measurement.

Customer Deposits

Customer Deposits - Customer deposits primarily represents advance billings and/or payments received from Avid’s third-party customers prior to the initiation of contract manufacturing services.

Revenue Recognition

Contract Manufacturing Revenue

License Revenue

Multiple Element Arrangements

If a licensing agreement includes multiple elements, a delivered item is considered a separate unit of accounting if both of the following criteria are met:

The delivered item has value to the licensing partner on a standalone basis based on the consideration of the relevant facts and circumstances for each agreement;

Milestone Payments

The consideration relates solely to past performance; and

The consideration is reasonable relative to all of the deliverables and payment terms within the arrangement.

Any milestone payments received prior to satisfying these revenue recognition criteria were recorded as deferred revenue in the accompanying consolidated financial statements.

Government Contract Revenue

Government Contract Revenue

The Government Contract was classified as a “cost-plus-fixed-fee” contract. We recognized government contract revenue in accordance with the authoritative guidance for revenue recognition including the authoritative guidance specific to federal government contracts. Reimbursable costs under the contract primarily include direct labor, subcontract costs, materials, equipment, travel, and indirect costs. In addition, we received a fixed fee for our efforts equal to 9.9% of the reimbursable costs incurred under the Government Contract, which was unconditionally earned as allowable costs were billed and was not contingent on success factors. Reimbursable costs under this Government Contract, including the fixed fee, were generally recognized as revenue in the period the reimbursable costs are incurred and become billable. However, when amounts billable, including the fixed fee, were not reasonably related to the proportionate performance of the total work or services to be performed, we recognized revenue on a proportional performance basis. In addition, reimbursable costs, including the fixed fee, associated with manufacturing services were recognized as revenue once delivery (or passage of title) had occurred.

Other Income

Other Income - Other income for the fiscal year ended April 30, 2011 includes a grant of $978,000 awarded to us under Section 48D of the Internal Revenue Code as reimbursement for four separate qualifying therapeutic discovery projects, which we applied for under the Patient Protection and Affordable Care Act of 2010.

Research and Development Expenses

Research and Development Expenses - Research and development costs are charged to expense when incurred in accordance with the authoritative guidance for research and development costs. Research and development expenses primarily include (i) payroll and related costs associated with research and development personnel, (ii) costs related to clinical and preclinical testing of our technologies under development, (iii) costs to develop and manufacture the product candidates, including raw materials and supplies, product testing, depreciation, and facility related expenses, (iv) expenses for research services provided by universities and contract laboratories, including sponsored research funding, and (v) other research and development expenses.

Accrued Clinical Trial and Related Fees

Accrued Clinical Trial and Related Fees - We accrue clinical trial and related fees based on work performed in connection with advancing our clinical trials, which relies on estimates and/or representations from clinical research organizations (“CROs”), hospitals, consultants, and other clinical trial related vendors. We maintain regular communication with our vendors, including our CRO’s, and gauge the reasonableness of estimates provided. However, actual clinical trial costs may differ from estimated clinical trial costs and are adjusted for in the period in which they become known. There were no material adjustments for a change in estimate to research and development expenses in the accompanying consolidated financial statements in any of the three years ended April 30, 2013.

Share-based Compensation

Income Taxes

Basic and Dilutive Net Loss Per Common Share

	2013		2012		2011
Stock options and awards		3,505,777		96,591		85,361
Employee stock purchase plan		307,501		110,469		20,327
Warrants		–		–		68,991
Total		3,813,278		207,060		174,679

Adoption of Recent Accounting Pronouncements

Adoption of Recent Accounting Pronouncements

Pending Adoption of Recent Accounting Pronouncements

Pending Adoption of Recent Accounting Pronouncements

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Apr. 30, 2013

Accounting Policies [Abstract]

Trade and Other Receivables

	2013		2012
Trade receivables⁽¹⁾	$	1,642,000	$	2,264,000
Other receivables, net		20,000		89,000
Trade and other receivables, net	$	1,662,000	$	2,353,000

Inventories

	2013		2012
Raw materials	$	2,169,000	$	1,966,000
Work-in-process		2,170,000		1,645,000
Total inventories	$	4,339,000	$	3,611,000

Antidilutive Shares

	2013		2012		2011
Stock options and awards		3,505,777		96,591		85,361
Employee stock purchase plan		307,501		110,469		20,327
Warrants		–		–		68,991
Total		3,813,278		207,060		174,679

3. NOTE PAYABLE AND CAPITAL LEASE OBLIGATIONS (Tables)

12 Months Ended

Apr. 30, 2013

Debt and Capital Lease Obligations [Abstract]

Equipment purchased under these capital leases

	2013			2012
Furniture, fixtures, office equipment and software	$	258,000		$	258,000
Less accumulated depreciation and amortization		(148,000	)		(96,000	)
Net book value	$	110,000		$	162,000

Minimum future capital lease payments

Year ending April 30,:
2014	$	34,000
2015		13,000
Total minimum lease payments		47,000
Amount representing interest		(2,000	)
Net present value minimum lease payments		45,000
Less current portion included in other current liabilities		(32,000	)
Long-term portion included in other long-term liabilities	$	13,000

6. STOCKHOLDERS' EQUITY (Tables)

12 Months Ended

Apr. 30, 2013

Equity [Abstract]

Shares Of Common Stock Authorized And Reserved For Future Issuance

	Number of Shares Reserved
Common shares reserved for issuance under outstanding option grants and common shares available for issuance under our stock incentive plans		20,081,954
Common shares reserved for and available for issuance under our Employee Stock Purchase Plan		3,438,559
Common shares issuable upon exercise of outstanding warrants		374,803
Total shares of common stock reserved for issuance		23,895,316

7. EQUITY COMPENSATION PLANS (Tables)

12 Months Ended

Apr. 30, 2013

Equity Compensation Plans Tables

Fair value valuation assumptions

The fair value of stock options on the date of grant and the weighted-average assumptions used to estimate the fair value of the stock options using the Black-Scholes option valuation model for fiscal years ended April 30, 2013, 2012 and 2011, were as follows:

	Year Ended April 30,
	2013	2012	2011
Risk-free interest rate	0.96%	1.44%	2.09%
Expected life (in years)	5.85	5.92	6.00
Expected volatility	95.87%	74.08%	73.42%
Expected dividend yield	-	-	-

The weighted average grant date fair value of purchase rights under the 2010 ESPP during fiscal years ended April 30, 2013, 2012 and 2011 was $0.40, $0.46 and $0.52, respectively, based on the following Black-Scholes option valuation model inputs:

	Year Ended April 30,
	2013	2012	2011
Risk-free interest rate	0.15%	0.06%	0.15%
Expected life (in years)	0.50	0.50	0.50
Expected volatility	167.36%	67.96%	82.72%
Expected dividend yield	-	-	-

Stock Options

The following summarizes our stock option transaction activity for fiscal year ended April 30, 2013:

Stock Options	Shares			Weighted Average Exercisable Price		Weighted Average Remaining Contractual Term (years)		Aggregate Intrinsic Value ⁽¹⁾
Outstanding, May 1, 2012		7,531,651		$	2.90
Granted		8,677,208		$	0.88
Exercised		(118,555	)	$	0.83
Canceled or expired		(803,096	)	$	1.58
Outstanding, April 30, 2013		15,287,208		$	1.84		8.07	$	5,294,000

Exercisable and expected to vest		15,086,905		$	1.85		8.05	$	5,228,000
Exercisable, April 30, 2013		7,434,607		$	2.67		6.86	$	1,811,000

Share-based compensation expense

	2013		2012		2011
Cost of contract manufacturing	$	89,000	$	12,000	$	8,000
Research and development		1,646,000		1,018,000		1,134,000
Selling, general and administrative		1,700,000		1,739,000		1,695,000
Total share-based compensation expense	$	3,435,000	$	2,769,000	$	2,837,000

Share-based compensation from:
Stock options	$	3,039,000	$	2,673,000	$	2,598,000
Restricted stock awards		–		–		185,000
Employee stock purchase plan		396,000		96,000		54,000
	$	3,435,000	$	2,769,000	$	2,837,000

9. INCOME TAXES (Tables)

12 Months Ended

Apr. 30, 2013

Income Tax Disclosure [Abstract]

Provision for income taxes

	2013			2012			2011
Provision for federal income taxes at statutory rate	$	(10,125,000	)	$	(14,321,000	)	$	(11,611,000	)
State income taxes, net of federal benefit		2,000			20,000			(406,000	)
Expiration and adjustment of loss carry forwards		(98,263,000	)		13,980,000			9,174,000
Change in valuation allowance		108,310,000			(95,000	)		2,294,000
Other, net		76,000			416,000			549,000
Income tax (expense) benefit	$	–		$	–		$	–

Deferred income taxes

	2013			2012

Share-based compensation	$	4,624,000		$	3,494,000
Deferred revenue		1,912,000			1,719,000
Depreciation and amortization		668,000			623,000
Accrued liabilities		1,677,000			693,000
Net operating losses		105,958,000			–

Total deferred tax assets		114,839,000			6,529,000
Less valuation allowance		(114,839,000	)		(6,529,000	)

Net deferred tax assets	$	–		$	–

11. SEGMENT REPORTING (Tables)

12 Months Ended

Apr. 30, 2013

Segment Reporting [Abstract]

Segment information

Segment information is summarized as follows:

	2013			2012			2011
Contract manufacturing services revenue	$	21,333,000		$	14,783,000		$	8,502,000
Cost of contract manufacturing services		12,595,000			10,153,000			7,296,000
Gross profit	$	8,738,000		$	4,630,000		$	1,206,000
Revenue from products in research and development	$	350,000		$	450,000		$	4,990,000
Research and development expense		(24,306,000	)		(35,688,000	)		(29,462,000	)
Selling, general and administrative expense		(13,134,000	)		(11,462,000	)		(11,421,000	)
Other income (expense), net		268,000			(49,000	)		536,000
Loss on early extinguishment of debt		(1,696,000	)		–			–
Net loss	$	(29,780,000	)	$	(42,119,000	)	$	(34,151,000	)

Revenue generated from our products in our research and development segment was derived from the following sources:

	2013		2012		2011
Government contract revenue¹ (see Note 2)	$	–	$	–	$	4,640,000
License revenue		350,000		450,000		350,000
Total	$	350,000	$	450,000	$	4,990,000

Customer Revenue

	2013	2012	2011
United States (customer A)	81%	44%	56%
United States (customer B)	17	-	-
Germany (one customer)	-	17	24
Denmark (one customer)	-	25	19
Other customers	2	14	1
Total	100%	100%	100%

Long-lived assets

	2013		2012
Long-lived Assets, net:
Contract manufacturing services	$	2,039,000	$	2,080,000
Products in research and development		639,000		820,000
Total	$	2,678,000	$	2,900,000

12. SELECTED QUARTERLY FINANCIAL DATA (Tables)

12 Months Ended

Apr. 30, 2013

Quarterly Financial Information Disclosure [Abstract]

Selected quarterly financial information for each of the two most recent fiscal

	Quarter Ended
	April 30,			January 31,			October 31,			July 31,			April 30,			January 31,			October 31,			July 31,
	2013			2013			2012			2012			2012			2012			2011			2011
Net revenues	$	4,254,000		$	7,039,000		$	6,139,000		$	4,251,000		$	2,065,000		$	3,281,000		$	4,242,000		$	5,655,000
Gross profit (a)	$	959,000		$	3,310,000		$	2,358,000		$	2,111,000		$	1,053,000		$	719,000		$	436,000		$	2,422,000
Loss from operations...	$	(8,463,000	)	$	(5,161,000	)	$	(7,057,000	)	$	(7,671,000	)	$	(10,890,000	)	$	(11,093,000	)	$	(12,036,000	)	$	(8,051,000	)
Net loss (b)	$	(8,449,000	)	$	(4,914,000	)	$	(8,753,000	)	$	(7,664,000	)	$	(10,882,000	)	$	(11,090,000	)	$	(12,055,000	)	$	(8,092,000	)
Basic and diluted loss per common share	$	(0.06	)	$	(0.04	)	$	(0.08	)	$	(0.07	)	$	(0.10	)	$	(0.13	)	$	(0.16	)	$	(0.11	)

	(a)	Gross profit represents contract manufacturing revenue less cost of contract manufacturing.

	(b)	Net loss for the quarter ended October 31, 2012, included a loss on the early extinguishment of debt of $1,696,000 (Note 4).

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	Apr. 30, 2013	Apr. 30, 2012
Summary Of Significant Accounting Policies Details
Trade receivables	$ 1,642,000	$ 2,264,000
Other receivables, net	20,000	89,000
Trade and other receivables, net	$ 1,662,000	$ 2,353,000

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 1) (USD $)	Apr. 30, 2013	Apr. 30, 2012
Summary Of Significant Accounting Policies Details 1
Raw materials	$ 2,169,000	$ 1,966,000
Work-in-process	2,170,000	1,645,000
Total inventories	$ 4,339,000	$ 3,611,000

3. NOTE PAYABLE AND CAPITAL LEASE OBLIGATIONS (Details) (USD $)	Apr. 30, 2013	Apr. 30, 2012
Debt and Capital Lease Obligations [Abstract]
Furniture, fixtures, office equipment and software	$ 258,000	$ 258,000
Less accumulated depreciation and amortization	(148,000)	(96,000)
Net book value	$ 110,000	$ 162,000

3. NOTE PAYABLE AND CAPITAL LEASE OBLIGATIONS (Details 1) (USD $)	Apr. 30, 2013
Debt and Capital Lease Obligations [Abstract]
2014	$ 34,000
2015	13,000
Total minimum lease payments	47,000
Amount representing interest	(2,000)
Net present value minimum lease payments	45,000
Less current portion included in other current liabilities	(32,000)
Long-term portion included in other long-term liabilities	$ 13,000

4. COMMITMENTS AND CONTINGENCIES (Details) (USD $)	Apr. 30, 2013
Commitments And Contingencies Details
2014	$ 1,072,000
2015	1,079,000
2016	1,079,000
2017	1,068,000
2018	730,000
Operating Leases, Future Minimum Payments Due	$ 5,028,000

7. EQUITY COMPENSATION PLANS (Details)	12 Months Ended
7. EQUITY COMPENSATION PLANS (Details)	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Option Grant
Risk-free interest rate	0.96%	1.44%	2.09%
Expected life (in years)	5 years 10 months 6 days	5 years 11 months 1 day	6 years
Expected volatility	95.87%	74.08%	73.42%
Expected dividend yield	0.00%	0.00%	0.00%
Shares purchased under the 2010 ESPP
Risk-free interest rate	0.15%	0.06%	0.15%
Expected life (in years)	6 months	6 months	6 months
Expected volatility	167.36%	67.96%	82.72%
Expected dividend yield	0.00%	0.00%	0.00%

7. EQUITY COMPENSATION PLANS (Details 1) (USD $)	12 Months Ended
7. EQUITY COMPENSATION PLANS (Details 1) (USD $)	Apr. 30, 2013
Number of Options
Number of Options Outstanding, Beginning	7,531,651
Number of Options Granted	8,677,208
Number of Options Exercised	(118,555)
Number of Options Cancelled or Expired	(803,096)
Number of Options Outstanding, Ending	15,287,208
Exercisable and expected to vest	15,086,905
Exercisable, April 30, 2013	7,434,607
Weighted Average Exercise Price
Weighted Average Exercise Price Outstanding, Beginning	$ 2.9
Weighted Average Exercise Price Granted	$ 0.88
Weighted Average Exercise Price Exercised	$ 0.83
Weighted Average Exercise Price Canceled	$ 1.58
Weighted Average Exercise Price Outstanding, Ending	$ 1.84
Weighted Average Exercise Price, Exercisable and expected to vest	$ 1.85
Weighted Average Exercise Price Exercisable, April 30, 2013	$ 2.67
Weighted Average Remaining Contractual Life (in years)
Weighted Average Remaining Contractual Life (in years) Outstanding, Beginning	8 years 25 days
Weighted Average Remaining Contractual Life (in years) Vested and expected to vest	8 years 18 days
Weighted Average Remaining Contractual Life (in years) Exercisable, April 30, 2013	6 years 10 months 10 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value Outstanding	$ 5,294,000
Aggregate Intrinsic Value vested and expected to vest	5,228,000
Aggregate Intrinsic Value Exercisable, April 30, 2013	$ 1,811,000

8. WARRANTS (Details) (USD $)	12 Months Ended
8. WARRANTS (Details) (USD $)	Apr. 30, 2013
Warrants outstanding	374,803
December 19, 2009
Warrants outstanding	101,523
Exercise price per share warrants	$ 1.4775
Expiration date of warrants	Dec. 19, 2013
August 30, 2012
Warrants outstanding	273,280
Exercise price per share warrants	$ 2.4700
Expiration date of warrants	Aug. 30, 2018

9. INCOME TAXES (Details) (USD $)	12 Months Ended
9. INCOME TAXES (Details) (USD $)	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Income Taxes Details
Provision for federal income taxes at statutory rate	$ (10,125,000)	$ (14,321,000)	$ (11,611,000)
State income taxes, net of federal benefit	2,000	20,000	(406,000)
Expiration and adjustment of loss carry forwards	(98,263,000)	13,980,000	9,174,000
Change in valuation allowance	108,310,000	(95,000)	2,294,000
Other, net	76,000	416,000	549,000
Income tax (expense) benefit	$ 0	$ 0	$ 0

9. INCOME TAXES (Details 1) (USD $)	Apr. 30, 2013	Apr. 30, 2012
Income Taxes Details 1
Share-based compensation	$ 4,624,000	$ 3,494,000
Deferred revenue	1,912,000	1,719,000
Depreciation and amortization	668,000	623,000
Accrued liabilities	1,677,000	693,000
Net operating losses	105,958,000	0
Total deferred tax assets	114,839,000	6,529,000
Less valuation allowance	(114,839,000)	(6,529,000)
Net deferred tax assets	$ 0	$ 0

11. SEGMENT REPORTING (Details) (USD $)	3 Months Ended								12 Months Ended
11. SEGMENT REPORTING (Details) (USD $)	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Segment Reporting Details
Contract manufacturing services revenue									$ 21,333,000	$ 14,783,000	$ 8,502,000
Cost of contract manufacturing services									12,595,000	10,153,000	7,296,000
Gross profit	959,000	3,310,000	2,358,000	2,111,000	1,053,000	719,000	436,000	2,422,000	8,738,000	4,630,000	1,206,000
Revenue from products in research and development									350,000	450,000	4,990,000
Research and development expense									(24,306,000)	(35,688,000)	(29,462,000)
Selling, general and administrative expense									(13,134,000)	(11,462,000)	(11,421,000)
Other income (expense), net									268,000	(49,000)	536,000
Loss on early extinguishment of debt									(1,696,000)	0	0
Net (loss)	$ (8,449,000)	$ (4,914,000)	$ (8,753,000)	$ (7,664,000)	$ (10,882,000)	$ (11,090,000)	$ (12,055,000)	$ (8,092,000)	$ (29,780,000)	$ (42,119,000)	$ (34,151,000)

11. SEGMENT REPORTING (Details 2) (USD $)	12 Months Ended
11. SEGMENT REPORTING (Details 2) (USD $)	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Segment Reporting Details 2
Government contract revenue	$ 0	$ 0	$ 4,640,000
License revenue	350,000	450,000	350,000
Total Revenue Products Research and Development	$ 350,000	$ 450,000	$ 4,990,000

12. SELECTED QUARTERLY FINANCIAL DATA (Details) (USD $)	3 Months Ended								12 Months Ended
12. SELECTED QUARTERLY FINANCIAL DATA (Details) (USD $)	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Quarterly Financial Information Disclosure [Abstract]
Net revenues	$ 4,254,000	$ 7,039,000	$ 6,139,000	$ 4,251,000	$ 2,065,000	$ 3,281,000	$ 4,242,000	$ 5,655,000	$ 21,683,000	$ 15,233,000	$ 13,492,000
Gross profit	959,000	3,310,000	2,358,000	2,111,000	1,053,000	719,000	436,000	2,422,000	8,738,000	4,630,000	1,206,000
Loss from operations	(8,463,000)	(5,161,000)	(7,057,000)	(7,671,000)	(10,890,000)	(11,093,000)	(12,036,000)	(8,051,000)
Net loss	$ (8,449,000)	$ (4,914,000)	$ (8,753,000)	$ (7,664,000)	$ (10,882,000)	$ (11,090,000)	$ (12,055,000)	$ (8,092,000)	$ (29,780,000)	$ (42,119,000)	$ (34,151,000)
Basic and diluted loss per common share	$ (0.06)	$ (0.04)	$ (0.08)	$ (0.07)	$ (0.10)	$ (0.13)	$ (0.16)	$ (0.11)	$ (0.25)	$ (0.50)	$ (0.56)

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Narrative) (USD $)	Apr. 30, 2013	Apr. 30, 2012
Allowance for doubtful accounts	$ 16,000	$ 19,000
Accounts Receivable [Member]
Major customer receivable concentration	97.00%	98.00%
TMT
Allowance for doubtful accounts	$ 92,000	$ 92,000

4. COMMITMENTS AND CONTINGENCIES (Narrative) (USD $)	12 Months Ended
4. COMMITMENTS AND CONTINGENCIES (Narrative) (USD $)	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Commitments And Contingencies Narrative
Annual rent expense	$ 938,000	$ 938,000	$ 939,000

10. BENEFIT PLAN (Details Narrative) (USD $)	12 Months Ended
10. BENEFIT PLAN (Details Narrative) (USD $)	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Benefit Plan Details Narrative
Matching contributions	$ 284,000	$ 232,000	$ 210,000

11. SEGMENT REPORTING (Details 1)	12 Months Ended
11. SEGMENT REPORTING (Details 1)	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Customer revenue as a percentage of revenue	100.00%	100.00%	100.00%
United States (Customer A)
Customer revenue as a percentage of revenue	81.00%	44.00%	56.00%
United States (Customer B)
Customer revenue as a percentage of revenue	17.00%	0.00%	0.00%
Germany (1 Customer)
Customer revenue as a percentage of revenue	0.00%	17.00%	24.00%
Denmark (1 Customer)
Customer revenue as a percentage of revenue	0.00%	25.00%	19.00%
Other Customers
Customer revenue as a percentage of revenue	2.00%	14.00%	1.00%

11. SEGMENT REPORTING (Details 3) (USD $)	Apr. 30, 2013	Apr. 30, 2012
Total Long-lived assets	$ 2,678,000	$ 2,900,000
Manufacturing Facility [Member]
Total Long-lived assets	2,039,000	2,080,000
Research and Development Expense [Member]
Total Long-lived assets	$ 639,000	$ 820,000

6. STOCKHOLDERS EQUITY (Details)	Apr. 30, 2013
Total shares of common stock reserved for issuance	23,895,316
Stock Incentive Plans
Total shares of common stock reserved for issuance	20,081,954
Employee stock purchase plan
Total shares of common stock reserved for issuance	3,438,559
Warrants
Total shares of common stock reserved for issuance	374,803