Washington Editor

Biomira Inc.'s stock plunged 62.8 percent Tuesday when the company and its partner, Merck KGaA, released disappointing news regarding a large Phase III trial of the metastatic breast cancer vaccine, Theratope.

The companies said the trial failed to reach its two primary endpoints of time to disease progression and overall survival. However, the good news, Biomira said, is that a prestratified subset of women on hormonal treatment following chemotherapy appeared to show a favorable trend to improvement in survival.

Still, Biomira's stock (NASDAQ:BIOM) fell $2.51 Tuesday to close at $1.49.

Of the news, Alex McPherson, president and CEO of Edmonton, Alberta-based Biomira, cautioned BioWorld Today that the companies began reviewing the data Friday and worked through the weekend, "so we've had a relatively short time to review 10,000 pages of graphs and figures, but there's no possibility in our minds that we will reach statistical significance at the predetermined level for either of the primary endpoints."

An interim analysis released in September suggested that the trial would not hit the endpoints, but a Data Safety Monitoring Board recommended the trial continue to completion. (See BioWorld Today, Sept. 20, 2002.)

Since the companies still are analyzing the data, McPherson was unable to provide specifics on certain elements of the trial, including the subset of women who demonstrated some activity. But he said the group represents about 30 percent of patients with metastatic breast cancer who were treated with chemotherapy and hormonal therapy.

The next move will be for the companies to meet with regulatory authorities (McPherson didn't say in which world market first) to decide how to proceed. McPherson hopes the first of these discussions will take place within the next three to five months.

While officials at Merck, of Darmstadt, Germany, were not available for comment, Nancy Wysenski, president of Merck's U.S. affiliate, EMD Pharmaceuticals Inc., of Durham, N.C., released a prepared statement saying, "We have additional clinical trials under way and plan to continue those Theratope trials while we fully evaluate the data from the Phase III metastatic breast cancer study and determine our next steps."

Biomira and Merck believe Theratope stimulates an immune response to tumors associated with the STn marker, which may lead to a therapeutic effect. The Phase III trial was designed primarily as a survival study. Enrollment included 1,030 women at 120 sites in 10 countries. The companies said Theratope was well tolerated, with most side effects being flu-like symptoms and local injection site reactions.

EMD Pharmaceuticals is in charge of a Phase II study of Theratope in women with metastatic cancer being treated with hormone therapy. Enrollment in the 95-patient study is expected to conclude late this year or early next year. Meanwhile, Biomira studied Theratope in a 20-patient Phase II trial of men and women for the treatment of colorectal cancer. McPherson said the colorectal cancer trial showed a median of 8.4 months in progression of disease.

Elsewhere in the pipeline, Merck and Biomira are collaborating on the development of BLP25 Liposomal vaccine. It's being studied in a 171-patient Phase IIb controlled study for non-small-cell lung cancer and a Phase II study of prostate cancer. The companies expect results later this year or early next year.

Biomira and Merck signed a partnership agreement in May 2001 to develop Theratope and BLP25. Biomira stands to make $150 million via the achievement of milestones. (See BioWorld Today, May 4, 2001.)