LONDON - EPTTCO Ltd. signed an agreement with Onyx Pharmaceuticals Inc. to arm Onyx's anticancer viruses with EPTCCO's prodrug converting enzymes.

Trevor Twose, CEO of EPTTCO, of Abingdon, Oxfordshire, told BioWorld International, "What's really good about this deal with Onyx is that they have a compound, Onyx-015, in Phase III, which is partnered with Pfizer Inc. We are looking for a small number of companies with the most advanced vectors to link up to our prodrug, and so are very pleased to have done this deal with Onyx."

The terms were not disclosed, but EPTTCO's prodrug will be available for linking to any vector in the Onyx portfolio. The companies will identify, evaluate and select novel prodrugs that are converted by nitroreductase, an enzyme that has the ability to convert a variety of small-molecule prodrugs into active cytotoxic agents.

As part of the deal, Onyx gains a license to the nitroreductase gene, plus the rights to license novel prodrugs discovered through the collaboration, for use with its Armed Therapeutic Virus platform. The viruses are able to selectively target and replicate in precancerous and cancerous cells without affecting normal cells.

EPTTCO was formed early in 1999 to commercialize prodrug activation systems developed by cancer charities and publicly funded research institutes. It brings together expertise from the Cancer Research Campaign, the Institute of Cancer Research and the Centre for Applied Microbiology in the UK with the Auckland Cancer Society Research Centre of the University of Auckland, New Zealand.

In April 1999, EPTTCO signed a deal with Vion Pharmaceuticals Inc. to arm Vion's anticancer therapy, TAPET. This vector is based on highly attenuated bacteria that demonstrated in preclinical studies preferential replication in tumors. In January 2000 AstraZeneca plc took an option on a version of Vion's TAPET bacterial vector, armed with EPTTCO's prodrug activation technology.

"The collaboration with Vion is going very well," Twose said. "TAPET is in Phase I. Although not armed, when administered systemically it has been shown to search out the tumor and selectively grow on the tumor. We are now working toward presenting the data to AstraZeneca."

Twose is looking now for new funding to enable EPTTCO to commercialize two further prodrug technologies, hypoxic prodrugs that are activated in areas of low oxygen concentration in tumors, and radiation-activated prodrugs that are administered and then activated by radiation.

"Although we have access to laboratories in New Zealand and London that can take prodrugs all the way through commercial development, the company itself has very little infrastructure and is run in a very lean fashion," he said. "However, I am now looking to raise more money to commercialize these other two technologies."