ANX Mast Therapeutics, Inc.

ADVENTRX Pharmaceuticals, Inc. (AMEX:ANX) today announced that patient follow up is nearly complete and data are being analyzed in its US-based Phase II COFU trial. COFU is a multi-center trial to evaluate the safety and efficacy of weekly treatment with CoFactor(TM) and 5-fluorouracil (5-FU) in patients with metastatic colorectal cancer. CoFactor is a biomodulator designed to enhance the effects and reduce the associated toxicity of the widely used cancer drug 5-FU. The Company also announced that two abstracts containing these COFU clinical data were submitted for consideration in the 2006 Gastrointestinal Cancers Symposium program. The symposium is sponsored in part by the American Society of Clinical Oncology (ASCO) and will be held in San Francisco, January 26-28, 2006. ADVENTRX completed patient enrollment in this Phase II clinical trial in January 2005 and met the primary endpoint for response rate and the secondary endpoint for safety. The Company announced preliminary investigator-reported tumor response and safety results in May and June 2005. The serial radiographical (CT) scans, which comprise the objective response data for all patients in the study, are being evaluated independently by a third party masked with respect to the investigator interpretations. These results will be included in the study findings, which the Company currently plans to report in the first quarter of 2006. "We continue to be encouraged by our CoFactor clinical program progress, including the positive preliminary results of our COFU trial demonstrating CoFactor's clinical benefit with reduced toxicity," said Evan M. Levine, president and CEO of ADVENTRX Pharmaceuticals. "In addition to our plan to report independently verified data from our COFU trial in the first quarter of 2006, we continue to ramp up our other clinical trials with CoFactor. We are currently conducting a multi-national Phase IIb trial using CoFactor plus 5-FU as a first line treatment of metastatic colorectal cancer, and we have also received clearance from the US Food and Drug Administration (FDA) to initiate a pivotal Phase III trial in the same indication. We are actively recruiting clinical sites in preparation for this Phase III trial and expect to begin treating patients in the first quarter of 2006." About CoFactor CoFactor (ANX-510) is a folate-based biomodulator drug developed to enhance the activity and reduce associated toxicity of the widely used cancer chemotherapeutic 5-FU. In comparison to leucovorin, CoFactor creates more stable binding of the active form of 5-FU, FdUMP, to the target enzyme, thymidylate synthase (TS). CoFactor bypasses the chemical pathway required by leucovorin to deliver the active form of folate, allowing 5-FU to work more effectively. This improves 5-FU performance and lowers toxicity. More information on CoFactor can be found at http://www.adventrx.com/products/antic_cofactor.htm. About ADVENTRX ADVENTRX Pharmaceuticals is a biopharmaceutical research and development company focused on introducing new technologies for anticancer and antiviral treatments that improve the performance and safety of existing drugs, by addressing significant problems such as drug metabolism, toxicity, bioavailability and resistance. More information can be found on the Company's Web site at www.adventrx.com. Forward Looking Statement This press release contains forward-looking statements within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. Such statements are made based on management's current expectations and beliefs. Actual results may vary from those currently anticipated based upon a number of factors, including uncertainties inherent in the drug development process, the timing and success of clinical trials, the validity of research results, and the receipt of necessary approvals from the FDA and other regulatory agencies. For a discussion of such risks and uncertainties, which could cause actual results to differ from those contained in the forward-looking statements, see "Risk Factors" in the Company's last quarterly report on Form 10-Q, as well as other reports that the Company files from time to time with the Securities and Exchange Commission. All forward-looking statements are qualified in their entirety by this cautionary statement. The Company undertakes no obligation to release publicly any revisions, which may be made to reflect events or circumstances after the date hereof.