Data Presented at AACR Annual Meeting Support Targeted Immune Reactivation Mechanism and Potential of Peregrine's Bavituximab

Data Presented at AACR Annual Meeting Support Targeted Immune Reactivation 
Mechanism and Potential of Peregrine's Bavituximab in
Solid Tumor Therapy 
Imaging Studies Show Docetaxel Strongly Upregulates Bavituximab's PS
Target in Tumors, Further Supporting Lead Clinical Indication in
Second Line Non-Small Cell Lung Cancer; Preclinical Studies Support
Potential of Bavituximab to Induce Cancer-Fighting Changes in Immune
Response to Tumors That Have Been Associated With Prolonged Survival
in Lung Cancer Patients 
TUSTIN, CA -- (Marketwired) -- 04/10/13 --  Peregrine
Pharmaceuticals, Inc. (NASDAQ: PPHM), a biopharmaceutical company
developing first-in-class monoclonal antibodies focused on the
treatment and diagnosis of cancer, today highlighted data presented
at the Annual Meeting of the American Association for Cancer Research
(AACR). Data was presented this week from preclinical studies
investigating the immune-stimulating mechanism of action of
Peregrine's lead phosphatidylserine (PS)-targeting oncology clinical
candidate bavituximab and the anti-tumor and imaging potential of
other PS-targeting molecules. Bavituximab is currently being
evaluated in several oncology clinical trials including the lead
indication of second-line non-small cell lung cancer (NSCLC), which
is ant
icipated to advance into a pivotal Phase III trial later this
year. 
"These studies yield important insights into the fundamental role
that exposed PS plays in tumor immune evasion, and further support
our lead clinical candidate bavituximab's ability to reactivate tumor
immunity. This is now clearly evidenced by several specific
measurements of both the immune-stimulating and anti-tumor mechanisms
mediated by PS-targeting antibodies as well as imaging studies
demonstrating that tumor growth inhibition is correlated with PS
expression levels in tumors," said Jeff T. Hutchins, Ph.D., vice
president of preclinical research at Peregrine Pharmaceuticals.
"Included in these presentations was a compelling finding of a
pronounced antibody-mediated increase in tumor-fighting immune cells
that is independently correlated with an impressive survival benefit
in patients with NSCLC based on a published retrospective study of
clinical data(1). When taken together, these results support PS as a
promising oncology drug target and provide additional rationale for
the impressive Phase II survival data we have seen in bavituximab's
lead indication of second-line NSCLC." 
Data presented from imaging studies(2) demonstrate that the
chemotherapeutic drug docetaxel, a commonly prescribed second-line
treatment for patients with advanced NSCLC, increases the exposure of
bavituximab's target molecule, phosphatidylserine (PS), on tumor
blood vessel cells and tumor cells. Results also showed that PS
exposure in tumors is correlated with tumor burden and response to
docetaxel treatment, supporting exposed PS as a promising biomarker
of cancer and response to therapy. Peregrine's PS-targeting imaging
agent I-124-PGN650 is currently being evaluated in a clinical trial
to assess its safety and potential to image multiple tumor types in
patients with cancer. 
Additional data presented from a series of preclinical studies(3)
demonstrate that PS-targeting antibodies mediate immuno-stimulatory
changes in tumors resulting in an increase of tumor-fighting (M1)
macrophages, immune cells strongly associated with survival benefits
in patients with NSCLC(1). Peregrine recently reported promising data
from a randomized, double-blind, placebo-controlled Phase II
second-line NSCLC clinical trial demonstrating a 60% improvement in
median overall survival (OS) in patients receiving 3 mg/kg
bavituximab plus docetaxel compared to the control arm. The company
plans to meet with the U.S. Food and Drug Administration (FDA) in the
second quarter of calendar year 2013 with the goal of initiating a
Phase III trial by calendar year-end. 
Researchers also presented details of new PS-binding constructs(4).
Termed "betabodies," the molecules consist of the PS-binding domain
of the serum protein β2-glycoprotein I (β2GPI), fused to
the constant region of an antibody. Betabodies bind to PS directly,
are smaller in size and have a longer serum half-life than natural
antibodies. Early studies indicate that betabodies hold potential as
next-generation PS-binding agents that have the potential to be used
for a broad number of applications including antibody-drug conjugates
and next generation therapeutics for oncology and infectious
diseases. 
(1) The M1 form of tumor-associated macrophages in non-small cell
lung cancer is positively associated with survival time. Ma et al.
BMC Cancer 2010, 10:112. Open access research article:
http://www.biomedcentral.com/content/pdf/1471-2407-10-112.pdf 
Presentation Details 
(2) Jian Gong(1), Richard Archer(1), Van Nguyen(1), Christopher C.W.
Hughes(2), Jeff Hutchins(1), Bruce Freimark(1). 1. Peregrine
Pharmaceuticals, Inc., Tustin, CA; 2. University of California,
Irvine, Irvine, CA. Predicting anti-tumor responses to
phosphatidylserine targeting antibodies using tumor imaging. In
Proceedings of t
he 104th Annual Meeting of the American Association
for Cancer Research (AACR); 2013 Apr 6-10; Washington, D.C. Abstract
2850  
(3) Yi Yin, Xianming Huang, Dan Ye, Philip Thorpe. UT Southwestern
Medical Ctr., Dallas, TX: Phosphatidylserine-targeting antibody
reactivates tumor immunity and destroys tumor vasculature in mice. In
Proceedings of the 104th Annual Meeting of the American Association
for Cancer Research (AACR); 2013 Apr 6-10; Washington, D.C. Abstract
1244  
(4) Xianming Huang(1), Dan Ye(1), Troy Luster(2), E. Sally Ward(1),
Philip Thorpe(1). 1. UT Southwestern Medical Ctr., Dallas, TX; 2.
Human Genome Science, Maryland, MD. Phosphatidylserine-targeting
'betabodies' for the treatment of cancer. In Proceedings of the 104th
Annual Meeting of the American Association for Cancer Research
(AACR); 2013 Apr 6-10; Washington, D.C. Abstract 4326 
Copies of the AACR posters are available at Peregrine's website at
http://www.peregrineinc.com/technology/bavituximab-oncology/recent-data.html 
About Bavituximab
 Bavituximab is a first-in-class phosphatidylserine
(PS)-targeting monoclonal antibody that represents a new approach to
treating cancer. Bavituximab is the lead drug candidate from the
company's PS technology platform and is currently being tested in
eight clinical trials, including three randomized Phase II trials in
front-line and second-line non-small cell lung cancer and front-line
pancreatic cancer, and five investigator-sponsored trials (ISTs) in
additional oncology indications. PS is a highly immunosuppressive
molecule usually located inside the membrane of healthy cells, but
"flips" and becomes exposed on the outside of cells that line tumor
blood vessels, creating a specific target for anti-cancer treatments.
PS-targeting antibodies target and bind to PS and block this
immunosuppressive signal, thereby enabling the immune system to
recognize and fight the tumor. 
About Peregrine Pharmaceuticals, Inc.
 Peregrine Pharmaceuticals,
Inc. is a biopharmaceutical company with a portfolio of innovative
monoclonal antibodies in clinical trials focused on the treatment and
diagnosis of cancer. The company is pursuing multiple clinical
programs in cancer with its lead product candidate bavituximab and
novel brain cancer agent Cotara(R). Peregrine also has in-house cGMP
manufacturing capabilities through its wholly-owned subsidiary Avid
Bioservices, Inc. (www.avidbio.com), which provides development and
biomanufacturing services for both Peregrine and third-party
customers. Additional information about Peregrine can be found at
www.peregrineinc.com. 
Safe Harbor Statement: Statements in this press release which are not
purely historical, including statements regarding Peregrine
Pharmaceuticals' intentions, hopes, beliefs, expectations,
representations, projections, plans or predictions of the future are
forward-looking statements within the meaning of the Private
Securities Litigation Reform Act of 1995. The forward-looking
statements involve risks and uncertainties including, but not limited
to, the risk that the major discrepancies discovered with respect to
our randomized, double-blind placebo-controlled Phase II trial of
bavituximab in patients with refractory NSCLC may cause regulatory
authorities to require further clinical trials to support a
registration package, the risks that partnering discussions may not
result in a partnering transaction or that such discussions could be
hindered or delayed as a result of the potential impact on the
regulatory pathway for bavituximab caused by the major discrepancies
discovered with respect to the Phase II NSCLC trial or the existing
class action lawsuits, the risk that the Company may not be able to
initiate a the pivotal Phase III trial within its anticipated
timeline, the risk that Peregrine may not have or raise adequate
financial resources to complete its other planned clinical programs
and the risk that the data from future clinical studies may not be
consistent with the data from the above preclinical studies. It is
important to note that the Company's actual results could differ
materially from those in any such forward-looking statements. Factors
that could cause actual results to differ materially include, but are
not limited to, uncertainties associated with completing preclinical
and clinical trials for our technologies; the early stage of product
development; the significant costs to develop our products as all of
our products are currently in development, preclinical studies or
clinical trials; obtaining additional financing to support our
operations and the development of our products; obtaining regulatory
approval for our technologies; anticipated timing of regulatory
filings and the potential success in gaining regulatory approval and
co
mplying with governmental regulations applicable to our business.
Our business could be affected by a number of other factors,
including the risk factors listed from time to time in our reports
filed with the Securities and Exchange Commission including, but not
limited to, our annual report on Form 10-K for the fiscal year ended
April 30, 2012 and our quarterly report on Form 10-Q for the quarter
ended January 31, 2013. The company cautions investors not to place
undue reliance on the forward-looking statements contained in this
press release. Peregrine Pharmaceuticals, Inc. disclaims any
obligation, and does not undertake to update or revise any
forward-looking statements in this press release.  
Contact:
Christopher Keenan or Jay Carlson
Peregrine Pharmaceuticals, Inc.
(800) 987-8256
info@peregrineinc.com