Matrix Reports Enhanced Anti-Cancer Activity of FMdC When Used in Combination; Pre-Clinical Data Presented at AACR Also Shows Differentiation of FMdC Versus Other Nucleoside Analogues.

Business Editors, Health/Medical Writers

SAN FRANCISCO--(BUSINESS WIRE)--April 4, 2000

Matrix Pharmaceutical, Inc., (Nasdaq:MATX) today announced that the results of three pre-clinical studies of FMdC, a novel systemic chemotherapeutic in clinical development as an anti-cancer agent, are being presented this week at the 91st Annual Meeting of the American Association for Cancer research (AACR) being held in San Francisco.

"Our pre-clinical studies show that FMdC may be effectively combined with other chemotherapeutics. In particular, a combination therapy using FMdC and cisplatin shows a significant increase in anti-tumor activity as compared to the activity of the two agents when used alone," said Richard Jones, Matrix Vice President of Research and Development. "The other important finding from our pre-clinical work is that FMdC is less susceptible to metabolic deactivation than other nucleoside analogues. This could result in improved therapeutic performance in humans versus other compounds."

Two of the studies to be presented help define the therapeutic potential of combining FMdC with other chemotherapeutic agents. The combination of FMdC and cisplatin resulted in apparently synergistic anti-tumor activity that was significantly greater than the sum of the two agents used alone in human lung cancer models in vitro and in mice. In colorectal cancer models, the combination was additive. The combination of FMdC and 5-FU also showed additive activity in colorectal cell lines.

The third study evaluated resistance of FMdC to cytidine deaminase, an enzyme found in many cancer cells. This enzyme tends to deactivate nucleoside analogues and makes cells more resistant to the drugs. In several different cell lines, it was demonstrated that FMdC is more resistant to cytidine deaminase deactivation than gemcitabine or cytarabine. Further analysis also suggests, unexpectedly, that tumor cell lines with higher levels of cytidine deaminase were more susceptible to FMdC than were cell lines with low enzyme activity. If these observations hold true in human clinical testing, it would provide important differentiation of FMdC from other nucleoside analogues.

Located in Fremont, California, Matrix Pharmaceutical, Inc. is developing novel local and systemic treatments for cancer. The Company's lead product, IntraDose Injectable Gel, has completed patient enrollment in two registration-directed Phase III trials in patients with recurrent or refractory head and neck cancer. The Company is also developing FMdC, a systemically administered new chemical entity, and MPI 5020, a radiopotentiator.

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