Document And Entity Information (USD $)	12 Months Ended
Document And Entity Information (USD $)	Apr. 30, 2012	Jul. 13, 2012	Oct. 31, 2011
Document and Entity Information [Abstract]
Entity Registrant Name	PEREGRINE PHARMACEUTICALS INC
Document Type	10-K
Current Fiscal Year End Date	--04-30
Entity Common Stock, Shares Outstanding		104,174,056
Entity Public Float			$ 85,913,295
Amendment Flag	false
Entity Central Index Key	0000704562
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	Apr. 30, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY

CONSOLIDATED BALANCE SHEETS (USD $)	Apr. 30, 2012	Apr. 30, 2011
CURRENT ASSETS:
Cash and cash equivalents	$ 18,033,000	$ 23,075,000
Trade and other receivables, net	2,353,000	1,389,000
Government contract receivables		93,000
Inventories, net	3,611,000	5,284,000
Prepaid expenses and other current assets, net	795,000	974,000
Total current assets	24,792,000	30,815,000
PROPERTY:
Leasehold improvements	1,383,000	932,000
Laboratory equipment	4,967,000	4,391,000
Furniture, fixtures, office equipment and software	2,287,000	1,814,000
	8,637,000	7,137,000
Less accumulated depreciation and amortization	(5,737,000)	(4,928,000)
Property, net	2,900,000	2,209,000
Other assets	570,000	1,742,000
TOTAL ASSETS	28,262,000	34,766,000
CURRENT LIABILITIES:
Accounts payable	3,492,000	4,046,000
Accrued clinical trial and related fees	2,111,000	2,292,000
Accrued payroll and related costs	2,468,000	1,455,000
Notes payable, current portion and net of discount		1,321,000
Deferred revenue, current portion	3,651,000	5,617,000
Customer deposits	4,865,000	1,759,000
Other current liabilities	1,052,000	1,189,000
Total current liabilities	17,639,000	17,679,000
Deferred revenue, less current portion	361,000	632,000
Other long-term liabilities	779,000	1,037,000
Commitments and contingencies
STOCKHOLDERS' EQUITY:
Preferred stock - $.001 par value; authorized 5,000,000 shares; non-voting; none issued
Common stock - $.001 par value; authorized 325,000,000 shares; outstanding - 101,421,365 and 69,837,142, respectively	101,000	70,000
Additional paid-in-capital	347,506,000	311,353,000
Accumulated deficit	(338,124,000)	(296,005,000)
Total stockholders' equity	9,483,000	15,418,000
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 28,262,000	$ 34,766,000

CONSOLIDATED BALANCE SHEETS (Parentheticals) (USD $)	Apr. 30, 2012	Apr. 30, 2011
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
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	101,421,365	69,837,142

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References+ Details

- Definition

Face amount or stated value per share of nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer); generally not indicative of the fair market value per share.

+ References+ Details

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	Apr. 30, 2012	Apr. 30, 2011	Apr. 30, 2010
REVENUES:
Contract manufacturing revenue	$ 14,783,000	$ 8,502,000	$ 13,204,000
Government contract revenue		4,640,000	14,496,000
License revenue	450,000	350,000	243,000
Total revenues	15,233,000	13,492,000	27,943,000
COSTS AND EXPENSES:
Cost of contract manufacturing	10,153,000	7,296,000	8,716,000
Research and development	35,688,000	29,462,000	24,658,000
Selling, general and administrative	11,462,000	11,421,000	8,182,000
Total costs and expenses	57,303,000	48,179,000	41,556,000
LOSS FROM OPERATIONS	(42,070,000)	(34,687,000)	(13,613,000)
OTHER INCOME (EXPENSE):
Interest and other income	41,000	1,052,000	116,000
Interest and other expense	(90,000)	(516,000)	(997,000)
NET LOSS	$ (42,119,000)	$ (34,151,000)	$ (14,494,000)
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING (in Shares)	83,572,761	60,886,392	49,065,322
BASIC AND DILUTED LOSS PER COMMON SHARE (in Dollars per share)	$ (0.50)	$ (0.56)	$ (0.30)

CONSOLIDATED STATEMENTS OF STOCKHOLDERS EQUITY (USD $)	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
BALANCES, April 30, at Apr. 30, 2009	$ 46,000	$ 248,215,000	$ (247,360,000)	$ 901,000
BALANCES, April 30, (in Shares) at Apr. 30, 2009	45,537,711
Common stock issued for cash (March 26, 2009)	2,000	6,585,000		6,587,000
Common stock issued for cash (July 14, 2009)	5,000	18,882,000		18,887,000
Common stock issued for cash (in Shares) (March 26, 2009)	1,855,172
Common stock issued for cash (in Shares) (July 14, 2009)	5,643,749
Common stock issued upon exercise of options		105,000		105,000
Common stock issued upon exercise of options (in Shares)	57,253
Fractional shares issued pursuant to reverse stock split (in Shares)	1,011
Share-based compensation		1,421,000		1,421,000
Net loss			(14,494,000)	(14,494,000)
BALANCES, April 30, at Apr. 30, 2010	53,000	275,208,000	(261,854,000)	13,407,000
BALANCES, April 30, (in Shares) at Apr. 30, 2010	53,094,896
Common stock issued for cash (July 14, 2009)	2,000	5,434,000		5,436,000
Common stock issued for cash (June 22, 2010)	9,000	14,645,000		14,654,000
Common stock issued for cash (December 29, 2010)	6,000	12,991,000		12,997,000
Common stock issued for cash (in Shares) (July 14, 2009)	1,925,565
Common stock issued for cash (in Shares) (June 22, 2010)	9,214,373
Common stock issued for cash (in Shares) (December 29, 2010)	5,224,491
Common stock issued upon exercise of options		44,000		44,000
Common stock issued upon exercise of options (in Shares)	20,750
Common stock issued upon exercise of warrants (in Shares)	74,802
Common stock issued for services		60,000		60,000
Common stock issued for services (in Shares)	28,921
Common stock issued under restricted stock awards (in Shares)	148,500
Common stock issued under Employee Stock Purchase Plan		134,000		134,000
Common stock issued under Employee Stock Purchase Plan (in Shares)	104,844
Share-based compensation		2,837,000		2,837,000
Net loss			(34,151,000)	(34,151,000)
BALANCES, April 30, at Apr. 30, 2011	70,000	311,353,000	(296,005,000)	15,418,000
BALANCES, April 30, (in Shares) at Apr. 30, 2011	69,837,142
Common stock issued for cash (December 29, 2010)	25,000	26,739,000		26,764,000
Common stock issued for cash (September 2, 2011)	6,000	6,409,000		6,415,000
Common stock issued for cash (in Shares) (December 29, 2010)	24,873,930
Common stock issued for cash (in Shares) (September 2, 2011)	6,252,252
Common stock issued under Employee Stock Purchase Plan		236,000		236,000
Common stock issued under Employee Stock Purchase Plan (in Shares)	458,041
Share-based compensation		2,769,000		2,769,000
Net loss			(42,119,000)	(42,119,000)
BALANCES, April 30, at Apr. 30, 2012	$ 101,000	$ 347,506,000	$ (338,124,000)	$ 9,483,000
BALANCES, April 30, (in Shares) at Apr. 30, 2012	101,421,365

CONSOLIDATED STATEMENTS OF STOCKHOLDERS EQUITY (Parentheticals) (Additional Paid-in Capital [Member], USD $)	12 Months Ended
	Apr. 30, 2010 March 26, 2009	Apr. 30, 2011 July 14, 2009	Apr. 30, 2010 July 14, 2009	Apr. 30, 2011 June 22, 2010	Apr. 30, 2012 December 29, 2010	Apr. 30, 2011 December 29, 2010	Apr. 30, 2012 September 2, 2011
Issuance costs related to Financings	$ 305,000	$ 133,000	$ 545,000	$ 345,000	$ 626,000	$ 291,000	$ 525,000

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	Apr. 30, 2012	Apr. 30, 2011	Apr. 30, 2010
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (42,119,000)	$ (34,151,000)	$ (14,494,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation	2,769,000	2,837,000	1,421,000
Depreciation and amortization	908,000	652,000	447,000
Amortization of discount on notes payable and debt issuance costs	33,000	235,000	430,000
Amortization of expenses paid in shares of common stock		956,000	239,000
Common stock issued for services		40,000
Loss on sale of property	2,000		49,000
Changes in operating assets and liabilities:
Trade and other receivables, net	(964,000)	92,000	289,000
Government contract receivables	93,000	274,000	1,577,000
Inventories, net	1,673,000	(2,161,000)	1,584,000
Prepaid expenses and other current assets, net	158,000	95,000	(777,000)
Other non-current assets	789,000	(7,000)	183,000
Accounts payable	(601,000)	608,000	(484,000)
Accrued clinical trial site and related fees	(181,000)	984,000	602,000
Accrued payroll and related expenses	1,013,000	(168,000)	43,000
Deferred revenue	(2,237,000)	3,843,000	(1,370,000)
Deferred government contract revenue		(78,000)	(3,793,000)
Customer deposits	3,106,000	(859,000)	331,000
Other accrued expenses and current liabilities	(62,000)	372,000	(232,000)
Other long-term liabilities	(258,000)	(26,000)	(6,000)
Net cash used in operating activities	(35,878,000)	(26,462,000)	(13,961,000)
CASH FLOWS FROM INVESTING ACTIVITIES:
Property acquisitions	(1,554,000)	(912,000)	(208,000)
Proceeds from sale of property			20,000
Decrease (increase) in other assets	383,000	(435,000)	(80,000)
Net cash used in investing activities	(1,171,000)	(1,347,000)	(268,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net of issuance costs of $1,151,000, $769,000, and $850,000, respectively	33,179,000	33,087,000	25,474,000
Proceeds from exercise of stock options		44,000	105,000
Proceeds from issuance of common stock under the Employee Stock Purchase Plan	236,000	134,000
Principal payments on notes payable	(1,333,000)	(2,000,000)	(1,667,000)
Principal payments on capital leases	(75,000)	(62,000)	(20,000)
Net cash provided by financing activities	32,007,000	31,203,000	23,892,000
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(5,042,000)	3,394,000	9,663,000
CASH AND CASH EQUIVALENTS, Beginning of year	23,075,000	19,681,000	10,018,000
CASH AND CASH EQUIVALENTS, End of year	18,033,000	23,075,000	19,681,000
SUPPLEMENTAL INFORMATION:
Interest paid	68,000	301,000	535,000
SCHEDULE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Property acquired under capital lease		180,000	78,000
Accounts payable and other liabilities for purchase of property	47,000	300,000	18,000
Other asset in exchange for future services		$ 233,000

1. ORGANIZATION AND BUSINESS DESCRIPTION

12 Months Ended

Apr. 30, 2012

Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]

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. 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 Bioservices, Inc., (“Avid”) in January 2002.

Business Description – We are a biopharmaceutical company developing first-in-class monoclonal antibodies for the treatment and diagnosis of cancer. We are advancing our two Phase II oncology programs with our lead product candidates, bavituximab and Cotara, for the treatment of various cancers. In addition, we are advancing our lead imaging agent, 124I-PGN650, into clinical development for the imaging of multiple solid tumor types.

With respect to our bavituximab oncology program, we are currently conducting three randomized Phase II trials for bavituximab in combination with standard chemotherapy for the treatment of second-line and front-line non-small cell lung cancer (“NSCLC”) and previously untreated pancreatic cancer. In addition to these company-sponsored trials for bavituximab, we are currently supporting four investigator-sponsored trials (“IST”) to evaluate new bavituximab drug combinations and additional oncology indications.

With respect to our Cotara oncology program, we have completed patient enrollment in our Phase II trial using Cotara for the treatment of recurrent glioblastoma multiforme (“GBM”), the deadliest form of brain cancer, and have entered into active discussion with the U.S. Food and Drug Administration (“FDA”) regarding a registration pathway for Cotara to further advance the program. 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, in April 2012, we filed an Investigational New Drug Application with the FDA to advance our lead imaging agent 124I-PGN650 into clinical development 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 Bioservices, Inc. (“Avid”). Avid is a Contract Manufacturing Organization 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 broad range of biomanufacturing services to third-party clients, Avid is strategically integrated with Peregrine to manufacture all clinical products to support our clinical trials while also preparing for potential commercial launch.

- Definition

The entire disclosure for organization, consolidation and basis of presentation of financial statements disclosure.

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+ Details

2. BASIS OF PRESENTATION

12 Months Ended

Apr. 30, 2012

Business Description and Basis of Presentation [Text Block]

BASIS OF PRESENTATION

Basis of Presentation - The accompanying consolidated financial statements include the accounts of Peregrine and its wholly-owned subsidiary, Avid Bioservices, Inc. 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.

Reclassification – Certain comparative amounts in fiscal year 2011 consolidated financial statements have been reclassified to conform to the current fiscal year presentation. These reclassifications had no effect on previously reported operating expenses or net loss.

Going Concern – Our consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The financial statements do not include any adjustments relating to the recoverability of the recorded assets or the classification of liabilities that may be necessary should it be determined that we are unable to continue as a going concern.

At April 30, 2012, we had $18,033,000 in cash and cash equivalents. We have expended substantial funds on the research, development and clinical trials 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 for the foreseeable future. Our net losses incurred during the past three fiscal years ended April 30, 2012, 2011 and 2010 amounted to $42,119,000, $34,151,000, and $14,494,000, respectively. 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 for the foreseeable future.

Therefore, 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 or debt.

Historically, we have funded a significant portion of our operations through the issuance of equity. During fiscal year 2012, we raised $34,330,000 in gross proceeds (Note 7). Subsequent to April 30, 2012 and through June 30, 2012 we raised an additional $1,496,000 in gross proceeds under an At Market Issuance Agreement (Note 7). As of June 30, 2012, additional shares of our common stock for aggregate gross proceeds of up to $185,886,000 may be available under our current effective shelf registration statements on Form S-3.

Although we believe we can raise sufficient capital to meet our obligations through fiscal year 2013, our ability to raise additional capital in the equity markets is also 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 trials 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.

In addition, although we have historically financed our operations through the issuance of equity, we may also raise additional capital 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, there can be no assurances that we will be successful in securing debt financing, license or partner our products in development, or generate additional revenue from Avid to complete the research, development, and clinical testing of our product candidates.

Therefore, based on these uncertainties surrounding our ability to raise sufficient capital to meet our obligations through fiscal year 2013 have raised substantial doubt regarding our ability to continue as a going concern.

3. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

12 Months Ended

Apr. 30, 2012

Significant Accounting Policies [Text Block]

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

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.

Accounts Receivable - Accounts receivable is recorded at the invoiced amount net of an allowance for doubtful accounts, if necessary. Trade and other receivables primarily include amounts billed for contract manufacturing services provided by Avid (“trade” receivables). Government contract receivables include amounts billed under a former government contract with the Transformational Medical Technologies (“TMT”) of the U.S. Department of Defense’s Defense Threat Reduction Agency, which expired on April 15, 2011. In addition, amounts unbilled under our former government contract with the TMT at April 30, 2012 and 2011, net of allowances, were $3,000 and $100,000, respectively, and are included in other assets in the accompanying consolidated financial statements.

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, 2012 and 2011, we determined an allowance for doubtful accounts of $19,000 and $20,000, respectively, was necessary with respect to trade and other receivables. With respect to our government contract receivables as of April 30, 2011, we determined no allowance for doubtful accounts was necessary.

In addition, amounts billed under our former contract with TMT include the reimbursement for provisional rates covering allowable indirect overhead and general and administrative cost (“Indirect Rates”). These Indirect Rates are initially estimated based on financial projections and are 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. As of April 30, 2012 and 2011, we recorded an unbilled receivable of $92,000 pertaining to the calculated difference between estimated and actual Indirect Rates, of which amounts at April 30, 2012 and 2011 are included in prepaid expenses and other current assets, respectively. However, due to the uncertainty of their collectability given that our actual Indirect Rates billed under our former contract with TMT have not been audited by the DCAA, 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, 2012 and 2011.

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,

	2012		2011
Raw materials, net	$	1,966,000	$	1,512,000
Work-in-process		1,645,000		3,772,000
Total inventories, net	$	3,611,000	$	5,284,000

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 - 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. As of April 30, 2012 and 2011, 94% and 93% of trade and other receivables, respectively, were from three customers.

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, accrued liabilities, and notes payable 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, 2012 and 2011, 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 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 revenues related to agreements associated with Peregrine’s technologies under development. In addition, from June 30, 2008 through April 15, 2011, we derived government contract revenues from services provided under a government contract awarded to us through the Transformational Medical Technologies (“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 generally 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. There were no “bill-and-hold” arrangements outstanding as of April 30, 2012 and 2011.

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. As of April 30, 2012 and 2011, we determined no provision for estimated contract losses was necessary.

License Revenue

Revenue associated with licensing agreements primarily consist 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 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. Amounts received prior to satisfying the above revenue recognition criteria are recorded as deferred revenue in the accompanying consolidated financial statements.

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

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.

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 Transformational Medical Technologies 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, of which during fiscal years 2011 and 2010, we recognized $4,640,000 and $14,496,000, respectively.

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 (“CRO”), hospitals, consultants, and other clinical trial related vendors. We maintain regular communication with our vendors, including our CRO vendors, 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, 2012.

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 remeasurement is recognized in the current period. See Note 8 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, 2012.

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,:

	2012		2011		2010
Stock options and awards		96,591		85,361		435,686
Employee stock purchase plan		110,469		20,327		—
Warrants		—		68,991		190,042
Total		207,060		174,679		625,728

The calculation of weighted average diluted shares outstanding also excludes weighted average outstanding stock options, stock awards and warrants to purchase 5,970,393, 4,338,813, and 1,759,861 shares of common stock for fiscal years ended April 30, 2012, 2011, and 2010, 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, 2012 and through June 30, 2012, we issued an aggregate of 2,752,691 shares of our common stock (Note 7), which are not included in the calculation of basic and dilutive net loss per common share for the year ended April 30, 2012.

Adoption of Recent Accounting Pronouncements

On May 1, 2011, we elected to adopt on a prospective basis Financial Accounting Standards Board’s (“FASB”) Accounting Standards Update (“ASU”) No. 2010-17, Revenue Recognition (Topic 605): Milestone Method of Revenue Recognition (“Milestone Method”). Under the Milestone Method contingent consideration received from the achievement of a substantive milestone is recognized in its entirety in the period in which the milestone is achieved, which we believe is more consistent with the substance of our performance under our various licensing agreements. 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 entity. A milestone is considered substantive when it meets all of the following criteria: (i) the consideration earned from the achievement of the milestone 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, (ii) the consideration relates solely to past performance, and (iii) the consideration is reasonable relative to all of the other deliverables and payments within the arrangement. The election to adopt the Milestone Method did not impact the accompanying consolidated financial statements. However, this policy election may result in revenue recognition patterns for future milestones that are materially different from those recognized for milestones received prior to adoption.

Milestone payments received prior to May 1, 2011 from arrangements where we have continuing performance obligations have been deferred and are recognized as revenue on a straight-line basis over the performance obligation period. We will continue to recognize milestones payments received prior to May 1, 2011 in this manner. As of April 30, 2012, we have deferred revenue of $306,000 from milestone payments received prior to May 1, 2011 that we are recognizing on a straight-line basis through July 2013.

On May 1, 2011, we elected to adopt on a prospective basis FASB’s ASU No. 2009-13, Revenue Recognition (Topic 605): Multiple-Deliverable Revenue Arrangements. ASU No. 2009-13 requires an entity to allocate arrangement consideration at the inception of an arrangement to all of its deliverables based on their relative selling prices. ASU No. 2009-13 eliminates the use of the residual method of allocation and requires the relative-selling-price method in all circumstances in which an entity recognizes revenue for an arrangement with multiple deliverables subject to Accounting Standards Code 605-25. This guidance became effective for revenue arrangements entered into or materially modified as of May 1, 2011. The adoption of ASU No. 2009-13 did not have a material impact on the accompanying consolidated financial statements.

On January 1, 2012, we adopted on a prospective basis FASB’s ASU No. 2011-04, Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurements and Disclosure Requirement in U.S. GAAP and IFRS. ASU No. 2011-04 modifies the existing standards to include disclosure of all transfer between Level 1 and Level 2 asset and liability fair value categories. In addition, ASU No. 2011-04 provides guidance on measuring the fair value of financial instruments managed within a portfolio and the application of premiums and discounts on fair value measurements. ASU No. 2011-04 also requires additional disclosure for Level 3 measurements regarding the sensitivity of fair value to changes in unobservable inputs and any interrelationships between those inputs. This guidance is effective for interim and annual periods beginning after December 15, 2011, with early adoption prohibited. The adoption of ASU No. 2001-04 did not have a material impact on the accompanying consolidated financial statements.

Pending Adoption of Recent Accounting Pronouncements

In June 2011 and December 2011, the FASB issued 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 (collectively, the “Updates”). 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 amendments in these Updates are effective for fiscal years, and interim periods within those years, beginning after December 15, 2011, which will be our fiscal year 2013 (or May 1, 2012). We do not expect the adoption of these Updates to have a material impact on our consolidated financial statements.

- Definition

The entire disclosure for all significant accounting policies of the reporting entity.

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4. NOTE PAYABLE AND CAPITAL LEASE OBLIGATIONS

12 Months Ended

Apr. 30, 2012

Debt Disclosure [Text Block]

NOTE PAYABLE AND CAPITAL LEASE OBLIGATIONS

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 payable over three years. On December 1, 2011, the loan balance was paid in full.

In connection with the term loan, we issued warrants to purchase an aggregate of 338,410 shares of our common stock at an exercise price of $1.48 per share. The fair value of the warrants was $414,000 and this amount was credited to additional paid-in capital and reduced the carrying value of the debt, reflected as a debt discount in the accompanying consolidated financial statements. The fair value of the warrants was determined using the Black-Scholes model with the following assumptions: estimated volatility of 70.72%; risk free interest rate of 2.00%; an expected life of five years; and no dividend yield. The debt discount was amortized as a non-cash interest expense over the term of the outstanding loan using the effective interest method. During fiscal years 2012, 2011, and 2010, we amortized $12,000, $113,000, and $202,000 in non-cash interest expense, which amounts are included in interest and other expense in the accompanying consolidated financial statements. The discount was fully amortized as of December 1, 2011.

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. During fiscal years 2012, 2011, and 2010, we amortized $21,000, $122,000, and $228,000 in non-cash interest expense, which amounts are included in interest and other expense in the accompanying consolidated financial statements. The debt issuance costs were fully amortized as of December 1, 2011.

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, 2012 and 2011, as follows:

	2012			2011
Furniture, fixtures, office equipment and software	$	258,000		$	258,000
Less accumulated depreciation and amortization		(96,000	)		(45,000	)
Net book value	$	162,000		$	213,000

Minimum future capital lease payments as of April 30, 2012 are as follows:

Year ending April 30,:
2013	$	82,000
2014		34,000
2015		13,000
Total minimum lease payments		129,000
Amount representing interest		(5,000	)
Net present value minimum lease payments		124,000
Less current portion included in other current liabilities		(78,000	)
Long-term portion included in other long-term liabilities	$	46,000

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

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5. COMMITMENTS AND CONTINGENCIES

12 Months Ended

Apr. 30, 2012

Commitments and Contingencies Disclosure [Text Block]

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 five-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, $939,000, and $807,000 for the fiscal years ended April 30, 2012, 2011 and 2010, respectively.

At April 30, 2012, future minimum lease payments under all non-cancelable operating leases are as follows:

Year ending April 30,:		Minimum Lease Payments
	2013	$	1,052,000
	2014		1,069,000
	2015		1,056,000
	2016		1,057,000
	2017		1,068,000
	Thereafter		730,000
		$	6,032,000

Legal Proceedings – From time to time, we are involved in legal disputes arising in the normal course of our business. We are not presently subject to 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.

- Definition

The entire disclosure for commitments and contingencies.

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6. LICENSE, RESEARCH AND DEVELOPMENT AGREEMENTS

12 Months Ended

Apr. 30, 2012

Revenue Recognition, Services, Licensing Fees [Policy Text Block]

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 under our phosphatidylserine (“PS”)-targeting and Tumor Necrosis Therapy (“TNT”) technology programs: bavituximab, 124 I-PGN650 (“PGN650”), and Cotara. In addition, we do not perform any research and development activities for any unrelated entities.

PS-Targeting Program

During fiscal year 2011, we expensed $114,000 associated with milestone obligations under in-licensing agreements covering our PS-targeting program, which is included in research and development expense in the accompanying consolidated statements of operations. We did not incur any milestone related expenses during fiscal years 2012 and 2010. In addition, no product revenues have been generated from the PS-targeting program to date. The following represents a summary of our current potential milestone obligations under our various agreements covering our bavituximab and PGN650 programs:

Bavituximab

In August 2001 and August 2005, we exclusively in-licensed the worldwide rights to the 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. 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 $122,000 U.S. based on the exchange rate at April 30, 2012). 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 $488,000 U.S. based on the exchange rate at April 30, 2012).

Of the total potential future milestone obligation of $6,800,000, we anticipate milestone obligations not to exceed $200,000 during fiscal year 2013. 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 a drug candidate developed under our PS-targeting program, including bavituximab, with the technologies licensed pursuant to such 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. Under this agreement, we do not anticipate any milestone obligations during fiscal year 2013.

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. Under the terms of the development and commercialization agreement, we have elected to enter into a license agreement for the PS-targeting antibody used to create PGN650, and therefore, are obligated to pay future milestones payments of up to $1,971,000 based on the achievement of certain potential clinical development and regulatory milestones, plus a low single digit royalty on net sales. We anticipate milestone obligations for PGN650 under this agreement to not exceed $101,000 during fiscal year 2013.

Tumor Necrosis Therapy Program (Cotara)

We acquired the patent rights to the Tumor Necrosis Therapy (“TNT”) technology, including 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 will 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 $488,000 U.S. based on the exchange rate at April 30, 2012) 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 fifteen (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 fifteen (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 milestones 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 years 2011 and 2010, we expensed $956,000 and $239,000, respectively, under the research collaboration agreement, the amounts of which are included in research and development expense in the accompanying consolidated financial statements. We did not incur any expenses under the research collaboration agreement during fiscal year 2012. We do not expect to incur any additional license fees or milestone payments under these agreements during fiscal year 2013 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 TNT 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 agreement, we would receive a royalty on net sales if a product is approved under the agreement. Merck KGaA has not disclosed the current development status of its program to Peregrine.

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 before the treatment of the first patient in a Phase I study, we shall receive forty-five percent (45%) of all payments received under any such sublicenses after Affitech deducts fifty percent (50%) of its incurred development costs under the program. 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 sub-licenses 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. However, we will continue to reassess the length of our obligation period, and accordingly, our estimated obligation period may change based on future events. We recognized revenue of $350,000 during fiscal years 2012 and 2011 and $243,000 during fiscal year 2010 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.

During May 2010, we entered into an assignment agreement and a license agreement (collectively, the “Agreements”) with an unrelated entity to develop our Tumor Necrosis Therapy (“TNT”) technologies in certain Asia-Pacific Economic Cooperation (“APEC”) countries. Under the terms of the Agreements, we licensed certain non-exclusive and exclusive rights and assigned certain exclusive development and commercialization rights under our TNT program in certain APEC countries. We have retained exclusive rights to our TNT program in the U.S., European Union countries, and other select countries internationally. Under the terms of the Agreements, aggregate fees in the amount of $500,000 are to be paid over a period of two years plus annual maintenance fees ranging from $100,000 to $250,000, as defined in the Agreements beginning May 2011 through 15 years following the date of the first commercial sale. In addition, we could also receive low double digit royalties on net sales, as defined in the Agreements. In accordance with the terms of the Agreements, we are obligated to deliver certain purchased patents, know-how and materials (the “Purchased Assets”), and we are obligated to supply certain quantities of research materials as defined in the Agreements. In addition, we have also agreed to provide certain manufacturing services, provided such manufacturing services are requested by the unrelated entity within a certain period of time and for certain agreed upon fees as defined in the Agreements. We have determined that, pursuant to the authoritative guidance for revenue recognition for multiple element arrangements, there was objective and reliable evidence of fair value of the undelivered elements (manufacturing commitment services) in the arrangement, but no such evidence of fair value for any other element in the arrangement. Therefore, we utilize the residual method to allocate the consideration received under the arrangement. Under the residual method, the amount of consideration allocated to all other elements in the arrangement (delivered and undelivered) equals the total arrangement consideration less the aggregate fair value of the undelivered elements with stand-alone fair value (manufacturing commitment services). To date, we have allocated the total arrangement consideration, excluding annual maintenance fees, to the undelivered elements with stand-alone fair value (manufacturing commitment services) since the fair value of these undelivered elements exceeded the total consideration received to date under the arrangement. As such, we will recognize revenue associated with the Purchased Assets and manufacturing commitment services we agreed to under the Agreements upon delivery of these manufacturing services based on the relative fair value of the services. However, during fiscal year 2012, we received a non-refundable annual maintenance fee of $100,000 in accordance with the terms of the Agreements, which amount is included in license revenue in the accompanying consolidated financial statements. Any amounts received prior to satisfying our revenue recognition criteria are recorded as deferred revenue in the accompanying consolidated financial statements.

- Definition

Disclosure of accounting policy for revenue recognition for licensing fees, which is consideration paid to the entity (licensor) by another party for the right to use, but not own, certain of the entity's intangible assets. Licensing arrangements include, but are not limited to, rights to use a patent, copyright, technology, manufacturing process, or trademark.

+ References+ Details

7. STOCKHOLDERS' EQUITY

12 Months Ended

Apr. 30, 2012

Stockholders' Equity Note Disclosure [Text Block]

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.

Financing Under Shelf Registration Statements On Form S-3

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, 2012, under three registration statements as defined below.

Shelf Filing Date	Registration Statement Number	Amount Registered
January 2007	File number 333-139975	$30,000,000
July 2009	File number 333-160572	$50,000,000
December 2010	File number 333-171252	$75,000,000

In addition, on March 9, 2012, we filed a shelf registration statement on Form S-3, File number 333-180028 (“March 2012 Shelf”), which was declared effective by the Securities and Exchange Commission on April 12, 2012, 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 $150,000,000. As of April 30, 2012, we had not issued any shares of common stock under the March 2012 Shelf.

The following table summarizes the various financing transactions and the amounts of capital we have raised under the shelf registration statements for the fiscal years ended April 30, 2010, 2011, and 2012:

Registration Statement No.	Description of Financing Transaction	Number of Common Stock Shares Issued	Gross Proceeds
Fiscal Year 2010
333-139975	At Market Sales Issuance Agreement dated March 26, 2009	1,855,172	$ 6,892,000
333-160572	At Market Sales Issuance Agreement dated July 14, 2009	5,643,749	$ 19,432,000
		7,498,921	$ 26,324,000
Fiscal Year 2011
333-160572	At Market Sales Issuance Agreement dated July 14, 2009	1,925,565	$ 5,568,000
333-160572	At Market Sales Issuance Agreement dated June 22, 2010	9,214,373	$ 15,000,000
333-171252	At Market Sales Issuance Agreement dated December 29, 2010	5,224,491	$ 13,288,000
		16,364,429	$ 33,856,000
Fiscal Year 2012
333-171252	At Market Sales Issuance Agreement dated December 29, 2010	24,873,930	$ 27,390,000
333-171252	Registered Direct Public Offering dated September 2, 2011	6,252,252	$ 6,940,000
		31,126,182	$ 34,330,000

Under the At Market Sales Issuance Agreement dated March 26, 2009 (“March 2009 AMI Agreement”) we entered into with Wm Smith & Co., pursuant to which we may sell shares of our common stock through Wm Smith & Co., as agent, in registered transactions from our January 2007 Shelf, for aggregate gross proceeds of $7,500,000. Shares of common stock sold under this arrangement were sold at market prices. During fiscal year 2010, we had sold 1,855,172 shares of common stock at market prices under the March 2009 AMI Agreement for aggregate gross proceeds of $6,892,000 before deducting commissions and other issuance costs of $305,000. As of April 30, 2010, we had raised the entire $7,500,000 available under the March 2009 AMI Agreement.

Under the At Market Sales Issuance Agreement dated July 14, 2009 (“July 2009 AMI Agreement”) we entered into with Wm Smith & Co., pursuant to which we may sell shares of our common stock through Wm Smith & Co., as agent, in registered transactions from our July 2009 Shelf, for aggregate gross proceeds of $25,000,000. Shares of common stock sold under this arrangement were sold at market prices. During fiscal years 2010 and 2011, we had sold 7,569,314 shares of common stock at market prices under the July 2009 AMI Agreement for aggregate gross proceeds of $25,000,000 before deducting commissions and other issuance costs of $678,000.

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

Under the At Market Sales Issuance Agreement dated December 29, 2010 (“December 2010 AMI Agreement”) with MLV, pursuant to which we may sell shares of our common stock through MLV, as agent, in registered transactions from our December 2010 Shelf, for aggregate gross proceeds of up to $75,000,000. Shares of common stock sold under this arrangement were sold at market prices. During fiscal years 2011 and 2012, we sold 30,098,421 shares of common stock at market prices under the December 2010 AMI Agreement for aggregate gross proceeds of $40,678,000 before deducting commissions and other issuance costs of $917,000. As of April 30, 2012, aggregate gross proceeds of up to $27,382,000 remained available under the December 2010 AMI Agreement.

Under the 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.

As of April 30, 2012, aggregate gross proceeds of up to $187,382,000 remained available under three effective shelf registration statements.

Subsequent to April 30, 2012 and through June 30, 2012, we sold 2,752,691 shares of common stock at market prices under the December 2010 AMI Agreement for aggregate gross proceeds of $1,496,000. As of June 30, 2012, aggregate gross proceeds of $185,886,000 remained available under our three effective shelf registration statements.

Shares Of Common Stock Authorized And Reserved For Future Issuance

As of April 30, 2012, we had reserved 16,963,060 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 statements, as further described in the following table:

	Number of Shares Reserved
Common shares reserved for issuance under outstanding option grants and available for issuance under our stock incentive plans		12,305,978
Common shares reserved for and available for issuance under our Employee Stock Purchase Plan		4,437,115
Common shares issuable upon exercise of outstanding warrants		219,967
Total shares of common stock reserved for issuance		16,963,060

- Definition

The entire disclosure for shareholders' equity, comprised of portions attributable to the parent entity and noncontrolling interest, if any, including other comprehensive income (as applicable). Including, but not limited to: (1) balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings; (2) accumulated balance for each classification of other comprehensive income and total amount of comprehensive income; (3) amount and nature of changes in separate accounts, including the number of shares authorized and outstanding, number of shares issued upon exercise and conversion, and for other comprehensive income, the adjustments for reclassifications to net income; (4) rights and privileges of each class of stock authorized; (5) basis of treasury stock, if other than cost, and amounts paid and accounting treatment for treasury stock purchased significantly in excess of market; (6) dividends paid or payable per share and in the aggregate for each class of stock for each period presented; (7) dividend restrictions and accumulated preferred dividends in arrears (in aggregate and per share amount); (8) retained earnings appropriations or restrictions, such as dividend restrictions; (9) impact of change in accounting principle, initial adoption of new accounting principle and correction of an error in previously issued financial statements; (10) shares held in trust for Employee Stock Ownership Plan (ESOP); (11) deferred compensation related to issuance of capital stock; (12) note received for issuance of stock; (13) unamortized discount on shares; (14) description, terms, and number of warrants or rights outstanding; (15) shares under subscription and subscription receivables, effective date of new retained earnings after quasi-reorganization and deficit eliminated by quasi-reorganization and, for a period of at least ten years after the effective date, the point in time from which the new retained dates; and (16) retroactive effective of subsequent change in capital structure.

+ References

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-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph d

-Article 4

+ Details

8. EQUITY COMPENSATION PLANS

12 Months Ended

Apr. 30, 2012

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

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, 2012, we had an aggregate of 12,305,978 shares of common stock reserved for issuance under the Stock Plans. Of those shares, 7,531,651 shares were subject to outstanding options and 4,774,327 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, 2012, 2011 and 2010, were as follows:

	Year Ended April 30,
	2012			2011			2010
Risk-free interest rate		1.44	%		2.09	%		2.69	%
Expected life (in years)		5.92			6.00			6.00
Expected volatility		74.08	%		73.42	%		73.30	%
Expected dividend yield		—			—			—

The following summarizes our stock option transaction activity for fiscal year ended April 30, 2012:

Stock Options	Shares			Weighted Average Exercisable Price		Weighted Average Remaining Contractual Term (years)		Aggregate Intrinsic Value ⁽¹⁾
Outstanding, May 1, 2011		4,869,599		$	4.16
Granted		3,615,063		$	1.51
Exercised		—		$	—
Canceled or expired		(953,011	)	$	4.04
Outstanding, April 30, 2012		7,531,651		$	2.90		7.72	$	—

Exercisable and expected to vest		7,402,248		$	2.93		7.69	$	—
Exercisable, April 30, 2012		4,152,663		$	4.08		6.33	$	—

⁽¹⁾

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, 2012, which was $0.47 per share.

The weighted-average grant date fair value of options granted to employees during the fiscal years ended April 30, 2012, 2011 and 2010 was $0.99, $1.31 and $1.99 per share, respectively.

The aggregate intrinsic value of stock options exercised during the fiscal years ended April 30, 2011 and 2010 was $5,000 and $82,000, respectively. Cash proceeds from stock options exercised during the fiscal years ended April 30, 2011 and 2010 totaled $44,000 and $106,000, respectively, excluding issuance costs of $0 and $1,000, 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, 2012, the total estimated unrecognized compensation cost related to non-vested stock options was $2,733,000. This cost is expected to be recognized over a weighted average vesting period of 1.96 years based on current assumptions.

Restricted Stock Awards – Restricted stock awards are grants that entitle the holder 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.

The following summarizes our restricted stock awards transaction activity for fiscal year ended April 30, 2012:

Restricted Stock	Shares			Weighted Average Grant Date Fair Value
Unvested, May 1, 2011		68,250		$	2.98
Granted		—		$	—
Vested		—		$	—
Forfeited		(68,250	)	$	2.98
Unvested, April 30, 2012		—		$	—

The weighted-average grant date fair value of restricted stock awards granted during fiscal years ended April 30, 2011 and 2010, was $2.37 and $2.97, respectively. No restricted stock awards were granted during fiscal year 2012. The total fair value of restricted stock awards vested during fiscal year ended April 30, 2011 was $404,000. No restricted stock awards vested during fiscal years 2012 and 2010. As of April 30, 2012, there was no unrecognized compensation cost related to unvested restricted stock awards.

Employee Stock Purchase Plan

On October 21, 2010, our stockholders approved our 2010 Employee Stock Purchase Plan. The 2010 Employee Stock Purchase Plan (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 4,437,115 shares remained available to purchase at April 30, 2012 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, 2012 and 2011, 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 $0.52 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, 2012 and 2011 was $0.46 and $0.52, respectively, based on the following Black-Scholes option valuation model inputs:

	Year Ended April 30,
	2012			2011
Risk-free interest rate		0.06	%		0.15	%
Expected life (in years)		0.50			0.50
Expected volatility		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, 2012, 2011 and 2010 was comprised of the following:

	2012		2011		2010
Cost of contract manufacturing	$	12,000	$	8,000	$	—
Research and development		1,018,000		1,134,000		784,000
Selling, general and administrative		1,739,000		1,695,000		637,000
Total share-based compensation expense	$	2,769,000	$	2,837,000	$	1,421,000

Share-based compensation from:
Stock options	$	2,673,000	$	2,598,000	$	1,202,000
Restricted stock awards		—		185,000		219,000
Employee stock purchase plan		96,000		54,000		—
	$	2,769,000	$	2,837,000	$	1,421,000

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 remeasurement is recognized in the current period. Share-based compensation expense recorded during fiscal years ended April 30, 2012, 2011 and 2010 associated with stock options and awards granted to non-employees amounted to $51,000, $114,000 and $113,000, respectively.

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

- Definition

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

+ References

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+ Details

10. INCOME TAXES

12 Months Ended

Apr. 30, 2012

Income Tax Disclosure [Text Block]

10.

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, 2012 and 2011. 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, 2012, 2011, and 2010, and we did not accrue for interest or penalties as of April 30, 2012 and 2011.

At April 30, 2012, we had total deferred tax assets of $6,529,000. 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. We have not yet performed a Section 382 analysis to determine the limitation of the net operating loss carry forwards. Until this analysis has been performed, we have removed the deferred tax assets for net operating losses of $97,372,000 generated through April 30, 2012 from our deferred tax asset schedule and have recorded a corresponding decrease to our valuation allowance. When this analysis is finalized, we plan to update our unrecognized benefits for uncertainty in income taxes. Due to the existence of the valuation allowance, future changes in our unrecognized tax benefits will not impact our effective tax rate.

At April 30, 2012, we had federal net operating loss carry forwards of approximately $254,394,000. The net operating loss carry forwards expire in fiscal years 2014 through 2033. Net operating losses of $806,000 applicable to Vascular Targeting Technologies, our wholly-owned subsidiary, can only be offset against future income of that subsidiary. We also have state net operating loss carry forwards of approximately $186,444,000 at April 30, 2012, which begin to expire in fiscal year 2014.

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

	2012			2011			2010
Provision for federal income taxes at statutory rate	$	(14,321,000	)	$	(11,611,000	)	$	(4,929,000	)
State income taxes, net of federal benefit		20,000			(406,000	)		(799,000	)
Expiration and adjustment of loss carry forwards		13,980,000			9,174,000			7,448,000
Change in valuation allowance		(95,000	)		2,294,000			(1,997,000	)
Other, net		416,000			549,000			277,000
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, 2012 and 2011 are as follows:

	2012			2011

Share-based compensation	$	3,494,000		$	2,782,000
Deferred revenue		1,719,000			2,677,000
Depreciation and amortization		623,000			691,000
Accrued liabilities		693,000			474,000
Total deferred tax assets		6,529,000			6,624,000
Less valuation allowance		(6,529,000	)		(6,624,000	)
Net deferred tax assets	$	—		$	—

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

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11. BENEFIT PLAN

12 Months Ended

Apr. 30, 2012

Pension and Other Postretirement Benefits Disclosure [Text Block]

11.

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 or a maximum of $17,000. 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 31, 2009. Effective January 1, 2010, the Company has 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 Company contributions to the Plan will fully vest after six years of service. The expense related to Company contributions to the Plan was $232,000, $210,000 and $58,000 for the fiscal years ended April 30, 2012, 2011 and 2010, respectively.

- Definition

The entire disclosure for pension and other postretirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

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12. SEGMENT REPORTING

12 Months Ended

Apr. 30, 2012

Segment Reporting Disclosure [Text Block]

12.

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 and infectious diseases. Avid is engaged in providing contract manufacturing services for Peregrine and outside customers on a fee-for-service basis.

The accounting policies of the operating segments are the same as those described in Note 3. 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 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:

	2012			2011			2010
Contract manufacturing services revenue	$	14,783,000		$	8,502,000		$	13,204,000
Cost of contract manufacturing services		10,153,000			7,296,000			8,716,000
Gross profit	$	4,630,000		$	1,206,000		$	4,488,000
Revenue from products in research and development	$	450,000		$	4,990,000		$	14,739,000
Research and development expense		(35,688,000	)		(29,462,000	)		(24,658,000	)
Selling, general and administrative expense		(11,462,000	)		(11,421,000	)		(8,182,000	)
Other income (expense), net		(49,000	)		536,000			(881,000	)
Net loss	$	(42,119,000	)	$	(34,151,000	)	$	(14,494,000	)

Revenue generated from our contract manufacturing segment was from the following customers:

	2012	2011	2010
Customer revenue as a percentage of revenue:
United States (customer A)	44%	56%	32%
United States (customer B)	0%	0%	15%
Germany (one customer)	17%	24%	23%
Denmark (one customer)	25%	19%	0%
Canada (one customer)	0%	0%	30%
Other customers	14%	1%	0%
Total	100%	100%	100%

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

	2012		2011		2010
Government contract revenue^1,2 (see Note 3)		—	$	4,640,000	$	14,496,000
License revenue (see Note 6)		450,000		350,000		243,000
Total	$	450,000	$	4,990,000	$	14,739,000

⁽¹⁾

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

⁽²⁾

Includes revenue associated with services provided by our contract manufacturing segment under our former government contract with the TMT, of which during fiscal years 2011 and 2010 amounted to $366,000 and $6,978,000, respectively.

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:

	2012		2011
Long-lived Assets, net:
Contract manufacturing services	$	2,080,000	$	1,511,000
Products in research and development		820,000		698,000
Total	$	2,900,000	$	2,209,000

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 131

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

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+ Details

13. SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)

12 Months Ended

Apr. 30, 2012

Quarterly Financial Information [Text Block]

13.

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,
	2012			2012			2011			2011			2011			2011			2010			2010
Net revenues	$	2,065,000		$	3,281,000		$	4,232,000		$	5,655,000		$	2,729,000		$	2,883,000		$	4,671,000		$	3,209,000
Gross profit (loss) (a)	$	1,053,000		$	719,000		$	436,000		$	2,422,000		$	559,000		$	196,000		$	624,000		$	(173,000	)
Loss from operations	$	(10,890,000	)	$	(11,093,000	)	$	(12,036,000	)	$	(8,051,000	)	$	(9,954,000	)	$	(8,843,000	)	$	(8,378,000	)	$	(7,512,000	)
Net loss	$	(10,882,000	)	$	(11,090,000	)	$	(12,055,000	)	$	(8,092,000	)	$	(10,014,000	)	$	(8,929,000	)	$	(7,513,000	)	$	(7,695,000	)
Basic and diluted loss per common share	$	(0.10	)	$	(0.13	)	$	(0.16	)	$	(0.11	)	$	(0.15	)	$	(0.14	)	$	(0.13	)	$	(0.14	)

________________

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

- Definition

The entire disclosure for the quarterly financial data in the annual financial statements. The disclosure may include a tabular presentation of financial information for each fiscal quarter for the current and previous year, including revenues, gross profit, income or loss before extraordinary items and earnings per share data. It also includes an indication if the information in the note is unaudited, comments on the aggregate effect of year-end adjustments, and an explanation of matters or transactions that affect comparability or are pertinent to an understanding of the information furnished.

+ References+ Details