By Lisa Seachrist

Washington Editor

Faced with competing patent positions and similar pre-clinical development products, Immunex Corp. and Genentech Inc. have joined forces to develop TRIAL/Apo2L as a new treatment for cancer.

The two biotechnology firms will share equally both the development costs and worldwide profits, should the drug be commercialized. The deal turns the potential competitors into collaborators.

"Anytime you get both the lawyers and the scientists excited about a deal, you know you are on to something," said Tim Warner, spokesperson for Seattle-based Immunex. "But it's important to point out that this is a molecule in its very early development stage. We don't want to raise expectations, because it's still a preclinical molecule."

Warner said Immunex scientists envision the molecule making the jump from animal testing to human trials as early as next year. However, all decisions about the development of the product will be made by a joint steering committee and product team. Those entities will be responsible for selecting a single lead molecule for development, managing the development process and allocating the clinical and manufacturing responsibilities to each company.

The basis of this collaboration is the various forms of TRAIL/Apo2L, also known as tumor necrosis factor (TNF)-related apoptosis-inducing ligand. TNF is a cytokine that can cause tumor cells to die. While exhibiting an enormous anti-tumor effect, TNF when given systemically results in toxic side effects.

However, TNF is only one of a number of cytokines that can interact with a variety of TNF receptors. By specifically binding to and activating TNF receptors that result in programmed cell death, or apoptosis, the researchers at Immunex and South San Francisco-based Genentech hope to kill tumor cells and avoid systemic toxicities.

TRAIL/Apo2L binds to at least four distinct receptors found on many tumor cells and signals the cells to destroy themselves. So far in preclinical tests, TRAIL/Apo2L has triggered apoptosis in a number of different tumor cells while at the same time sparing normal cells. In preclinical animal models, the molecule has suppressed tumor growth and caused remission of tumors. To date, the toxicities found with other agents of apoptosis haven't been observed with TRAIL/Apo2L.

"So far, it doesn't have the toxicities that other agents have had," Warner said. "It's obviously cleared some preclinical hurdles that others haven't. But it's still a long way to a new therapy for cancer."

However, the fact that Genentech entered into the collaboration is a "strong endorsement" of TRAIL/Apo2L's mechanism of action and potential, said Mike King vice president and senior biotechnology analyst at BancBoston Robertson Stephens, in New York. In addition, King cites Genentech's oncology franchise as making that company the ideal partner for Immunex.

Matthew Geller, senior biotech analyst with CIBC Oppenheimer Corp., in New York, said the collaboration is a means to avoid potentially costly patent litigation.

"They both had patents in the area and it was a coincidence that they had similar products in development," Geller said. "In effect, rather than fight it out in the courts, they decided to work together."

Immunex's stock (NASDAQ:IMNX) closed Tuesday at $122.625, down $7.50 a share. Genentech's stock (NYSE:GNE) ended the day at $86.812, down $0.75 per share.