ANX Mast Therapeutics, Inc.

ADVENTRX Presents Results at International Conference on Antiviral Research SAN DIEGO, May 3 /PRNewswire-FirstCall/ -- ADVENTRX Pharmaceuticals, Inc. (AMEX:ANX), a biopharmaceutical research and development company focused on commercializing proprietary product candidates for the treatment of cancer and infectious diseases, announced today that it presented results demonstrating synergistic activity against human and avian influenza (bird flu) viruses when the Company's broad-spectrum antiviral drug candidate, ANX-201 (thiophosphonoformic acid), was combined with oseltamivir phosphate (Tamiflu(R)) in preclinical tests. ANX-201 also demonstrated single agent antiviral activity against these viruses. The results were presented at the International Conference on Antiviral Research (ICAR) in Palm Springs, CA on Wednesday, May 2nd. "These results suggest we can simultaneously improve efficacy and lower dosages with a two drug regimen of ANX-201 and Tamiflu," said Evan M. Levine, chief executive officer of ADVENTRX. "We intend to continue to investigate the use of ANX-201 in avian flu." As a single agent, ANX-201 showed dose-dependent antiviral activity against human, equine and avian influenza virus. Fixed-dose combinations of ANX-201 and the neuraminidase inhibitor Tamiflu produced a supra-additive, or synergistic, antiviral activity against the human and avian influenza viruses, as demonstrated by an overall lowering of the drug concentrations required to achieve virus inhibition. ANX-201 dosage could be reduced up to 10 fold against human influenza strains H3N2 and H1N1, and up to 100 fold against avian influenza strain H5N2 when administered in combination with Tamiflu. Tests were performed in vitro using standard cell-based influenza infectivity assays. A copy of the poster presentation is available for download from the "Resources" section of the Company's web site at http://www.adventrx.com/ under "Publications." About ANX-201 ANX-201 (thiophosphonoformic acid) is a pyrophosphate analog and member of a new class of reverse transcriptase inhibitor (RTI) for HIV. ANX-201 has shown activity against HIV drug-resistant clinical isolates and has shown synergy with nucleoside RTIs (NRTIs) in preclinical studies. The resistance profile of ANX-201 is unique among approved RTIs and contains mutations that have been shown to resensitize NRTI-resistant virus. In preclinical studies, ANX-201 has shown broad-spectrum antiviral activity against HIV-1, HIV-2, human and avian influenza viruses, and herpes simplex viruses 1 and 2 (HSV-1 and HSV-2). ADVENTRX plans to initiate a Phase 1/2 clinical trial of ANX-201 as a component of multi-drug therapy for the treatment of HIV during 2007. About ADVENTRX Pharmaceuticals ADVENTRX Pharmaceuticals is a biopharmaceutical research and development company focused on commercializing proprietary product candidates for the treatment of cancer and infectious diseases. The Company seeks to improve the performance and safety of existing treatments by addressing significant problems such as drug metabolism, bioavailability, excessive toxicity and treatment resistance. More information can be found on the Company's web site at http://www.adventrx.com/. Forward Looking Statement ADVENTRX cautions you that statements included in this press release that are not a description of historical facts are forward-looking statements that involve risks and assumptions that, if they materialize or do not prove to be accurate, could cause ADVENTRX's results to differ materially from historical results or those expressed or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to: the validity of research results; the risk that preclinical results are not indicative of the success of subsequent clinical trials and that products will not perform as preclinical data suggests or as otherwise anticipated; unexpected adverse side effects or inadequate therapeutic efficacy of ANX-201 and other uncertainties inherent in the drug development process; the timing and success of clinical trials; difficulties or delays in developing, testing, manufacturing, and obtaining regulatory approval for ANX-201, including receiving necessary regulatory approvals for a Phase 1/2 clinical trial of ANX-201; the risk that ADVENTRX will be unable to raise sufficient capital to fund the projects necessary to meet its anticipated or stated goals and milestones, including funding the continued development of ANX-201 for the treatment of HIV or human or avian influenza; and other risks and uncertainties more fully described in ADVENTRX's press releases and public filings with the Securities and Exchange Commission. ADVENTRX's public filings with the Securities and Exchange Commission are available at http://www.sec.gov/. ADVENTRX does not intend to update any forward-looking statement, including as set forth in this press release, to reflect events or circumstances arising after the date on which it was made. DATASOURCE: ADVENTRX Pharmaceuticals, Inc. CONTACT: Investors, Ioana C. Hone of ADVENTRX Pharmaceuticals, +1-858-552-0866; or Media, Amy Martini of WeissComm Partners, +1-212-301-7223, for ADVENTRX Pharmaceuticals Web site: http://www.adventrx.com/ Company News On-Call: http://www.prnewswire.com/comp/920134.html

Copyright