BioSante Announces Positive Leukemia Vaccine Results

Johns Hopkins Researchers Say Vaccine Appears to “Mop Up” Leukemia Cells Gleevec Leaves Behind

LINCOLNSHIRE, Ill.--(BUSINESS WIRE)--Mar 11, 2010 - <!--cpurl-->BioSante<!--/cpurl--> Pharmaceuticals, Inc. (NASDAQ: BPAX) today announced positive results of a human clinical study that show that its <!--ppurl-->GVAX<!--/ppurl--> Leukemia vaccine may be able to reduce or eliminate the last remaining cancer cells in some chronic myeloid leukemia (CML) patients taking the drug <!--ppurl-->Gleevec<!--/ppurl--> (imatinib mesylate). All patients enrolled in the trial used Gleevec for at least one year and still had cancer cells present. The study was conducted by researchers at the Johns Hopkins Kimmel Cancer Center in Baltimore, Maryland, led by Hyam Levitsky, M.D., professor of oncology, medicine and urology at the Cancer Center. The research was funded by the National Institutes of Health.

In a study published in Clinical Cancer Research, Johns Hopkins Sidney Kimmel Comprehensive Cancer Center investigators used a vaccine made from CML cells irradiated to halt their cancerous potential and genetically altered to produce an immune system stimulator called GM-CSF. The treated cells also carry molecules, called antigens, specific to CML cells, which prime the immune system to recognize and kill circulating CML cells.

“We want to get rid of every last cancer cell in the body, and using cancer vaccines may be a good way to mop up residual disease,” said Dr. Levitsky. “More research to confirm and expand the results is needed,” Levitsky said.

The GVAX Leukemia vaccine was given to 19 CML patients with measurable cancer cells, despite taking Gleevec for at least one year (range 13-53 months). Each patient was given a series of four vaccines administered in three-week intervals while remaining on a stable dose of Gleevec. After a median of 72 months of follow-up, the number of remaining cancer cells declined in 13 patients, eight of whom had increasing disease burden before vaccination. Twelve patients reached their lowest levels of residual cancer cells to date following vaccination. In seven patients, CML became completely undetectable.

Patients receiving the GVAX Leukemia vaccine experienced relatively few side effects that included injection site pain and swelling, occasional muscle aches and mild fevers.

“We are very excited by these GVAX Leukemia vaccine data,” said Stephen M. Simes, BioSante's president & CEO. “Johns Hopkins Kimmel Cancer Center work in leukemia using BioSante's GVAX is one of many different forms of cancer being investigated, including pancreatic cancer, breast cancer and multiple myeloma. We look forward to working with Johns Hopkins's investigators to bring better cancer therapies to patients in need. BioSante owns the commercial rights to all GVAX vaccines as a result of our acquisition in 2009 of Cell Genesys.”

According to the investigators, most patients with CML will need to remain on Gleevec therapy for the rest of their lives. More than 90 percent of them will achieve remission, but about 10 to 15 percent of patients cannot tolerate the drug long term. Gleevec, one of the first targeted cancer therapies with wide success in CML patients, destroys most leukemic cells in the body, but in most patients, some cancerous cells remain and are measurable with sensitive molecular tests. These remaining cells are a source of relapse, according to the investigators, especially if Gleevec therapy is stopped.

In 2010, approximately 5,050 new cases will be diagnosed with CML and approximately 470 people will die. The average person's lifetime risk of getting CML is about 1 in 645. The average age at diagnosis of CML is around 66 years. Over half of cases are diagnosed in people 65 and older. This type of leukemia mainly affects adults, and is rarely seen in children.

About BioSante Pharmaceuticals, Inc.

BioSante is a specialty pharmaceutical company focused on developing products for female sexual health, menopause, contraception and male hypogonadism. BioSante's lead products include LibiGel® (transdermal testosterone gel) in Phase III clinical development by BioSante under a U.S. Food and Drug Administration (FDA) SPA (Special Protocol Assessment) for the treatment of female sexual dysfunction (FSD), and Elestrin™ (estradiol gel) developed through FDA approval by BioSante, indicated for the treatment of moderate-to-severe vasomotor symptoms associated with menopause, currently marketed in the U.S. Also in development are Bio-T-Gel™, a testosterone gel for male hypogonadism, licensed to Teva Pharmaceuticals (NASDAQ: TEVA) and an oral contraceptive in Phase II clinical development using BioSante patented technology. The current market in the U.S. for estrogen and testosterone products is approximately $2.5 billion and for oral contraceptives approximately $3 billion. The company also is developing its calcium phosphate technology (CaP) for aesthetic medicine (BioLook™), as a vaccine adjuvant, including for an H1N1 (swine flu) vaccine, and drug delivery. In addition, BioSante will seek opportunities for its GVAX cancer immunotherapies, 2A/Furin and other technologies. Additional information is available online at: www.biosantepharma.com.

Forward-Looking Statements

This news release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements often can be identified by words such as “will,” “potential,” “could,” “can,” “believe,” “intends,” “continue,” “plans,” “expects,” “anticipates,” “estimates,” “may” or the negative of these words or other words of similar meaning. Forward-looking statements by their nature address matters that are, to different degrees, uncertain. Uncertainties and risks may cause BioSante's actual results to be materially different than those expressed in or implied by BioSante's forward-looking statements. For BioSante, particular uncertainties and risks include, among others, the difficulty of developing pharmaceutical products, obtaining regulatory and other approvals and achieving market acceptance; the possibility that early clinical results will not be repeated in larger scale clinical trials; the marketing success of BioSante's licensees or sublicensees; the success of clinical testing; BioSante's need for and ability to obtain additional financing; the effect of general business and economic conditions; and risks arising from BioSante's merger with Cell Genesys. More detailed information on these and additional factors that could affect BioSante's actual results are described in BioSante's filings with the Securities and Exchange Commission, including its registration statement on Form S-4 filed in connection with the merger with Cell Genesys and BioSante's most recent annual report on Form 10-K and subsequent quarterly reports on Form 10-Q. The information set forth in this news release speaks only as of the date hereof, and BioSante undertakes no obligation to update or revise any forward looking statement, whether as a result of new information, future events or otherwise.

Gleevec (imatinib mesylate) is marketed in the U.S. by and is a trademark of Novartis Pharmaceuticals Corporation.

Contact: Alan Zachary, McKinney/Chicago; (312) 944-6784 ext. 316; azachary@mckinneychicago.com

Posted: March 2010

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