By Debbie Strickland
Less than a week after the release of "spectacular" trial results on a collaborative metastatic cancer product, Chiron Corp. has joined forces with a second smaller company whose technology, at the Phase II stage, looks promising. This time, the collaboration is with Biomira Inc., of Edmonton, Alberta, to co-develop a synthetic cancer vaccine to treat metastatic breast cancer.
Last week, the junior partner was San Diego-based DepoTech, whose DepoCyt treatment for neoplastic meningitis breezed through Phase III and appears headed for FDA approval this year.
"Chiron strongly believes in the power of the immune system, when stimulated, to fight cancer," said spokeswoman Kimberly Sankaran.
Theratope, a synthetic, carbohydrate-based vaccine, is designed to stimulate a patient's own immune system to control the disease with minimal side effects. If it wins FDA approval, it will be marketed by Chiron Therapeutics, the Emeryville, Calif., company's cancer drug marketing subsidiary.
As Sankaran noted, "We have yet to do Phase III, so there is some risk involved, but the Phase II data we saw were good and we are optimistic about Theratope's potential."
In a Phase II trial involving metastatic breast cancer patients, the drug boosted survival to 26.5 months, a statistically significant improvement over the control group's 9.1 months. Control patients were selected from the U.S. Oncology Database.
"That's a Phase II trial, with relatively small numbers," said Alex McPherson, Biomira's president and chief executive officer. "But the correlation between antibody response and improved survival caught the attention of Chiron scientists."
The two companies will share equally U.S. and European research and development costs, as well as clinical and regulatory costs. Details about the revenue apportionment and the timing and amounts of milestone payments were not disclosed.
A joint management committee, comprised of representatives from each company, will oversee the development of Theratope indications in the U.S. and Europe.
Metastatic breast cancer affects about 50,000 to 65,000 patients in the U.S., McPherson said. The companies are also investigating Theratope's potential for treating metastatic ovarian and colon cancers.
Results from the Phase II trial were encouraging enough to plan a Phase III trial, whose protocol may be finalized this quarter. The vaccine has thus far been tested in over 300 patients in Canada, the U.S. and the U.K..
"We hope to get Phase III up and running in early 1998," McPherson said.
"There's an indication of improvement in survival--there's no question about that," he said. "There is some indication of correlation between antibody production and improved survival."
Biomira, Canada's fifth largest biotechnology company, calls Theratope its "flagship product."
The company's Toronto-based subsidiary, Biomira Diagnostics Inc., markets Truquant in-vitro diagnostic products for monitoring breast, ovarian and gastrointestinal cancers; and the Truquant BR blood test kit for the detection of recurrent breast cancer.
At the end of the most recent quarter, Biomira had $89.9 million in cash, and a burn rate averaging $18 million per year. The company's shares (NASDAQ:BIOMF), which also are traded in Canada, closed Monday at $5.812, up $0.062.
For Chiron, whose revenues last year topped $1.3 billion, the product would add to a growing lineup of cancer treatments, including Aredia, which treats, among other things, bone metastases associated with breast cancer; and Proleukin, a treatment for metastatic kidney cancer. The company has filed a supplemental new drug application with the FDA to use Proleukin to treat metastatic melanoma.
Chiron's stock (NASDAQ:CHIR) ended the day at $20, up $0.75. *