ANX-201 Drug Combination Demonstrates Synergistic Activity Against Human and Bird Flu Viruses

ADVENTRX Presents Results at International Conference on Antiviral Research

May 03, 2007, 01:00 ET from ADVENTRX Pharmaceuticals, Inc.

    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 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
     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 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.

SOURCE ADVENTRX Pharmaceuticals, Inc.