Seattle Genetics Gets Early FDA Nod for Breast Cancer Combo Drug

Xconomy Seattle — 

Seattle Genetics on Friday received its third FDA approval, a regulatory nod for a breast cancer drug for patients with an especially aggressive form of the disease, four months ahead of schedule.

The Bothell, WA-based biotech earned the earlier-than-expected decision for its oral drug tucatinib (Tukysa), when taken in combination with the chemotherapies trastuzumab and capecitabine. The approval covers patients with a subtype of breast cancer that overproduces human epidermal growth factor receptor 2, or HER2, that can’t be surgically removed or has spread beyond its primary site.

Patients approved to receive the Seattle Genetics (NASDAQ: SGEN) treatment, who must have received at least one prior anti-HER2 treatment, include those with HER2-positive cancer that has spread to the brain.

In the US, the list price for the treatment is $18,500 for a 30-day supply, or $111,000 for an average course of treatment, Chip Romp, SeGen’s chief financial officer, said Friday on a conference call.

This year an estimated 279,100 new cases of breast cancer will be diagnosed in the US; about 15 to 20 percent of breast cancers are HER2-positive, and in about half of patients with the subtype, the disease is likely to spread to the brain.

More than 600 patients participated in the trial that provided the data that was the basis for the FDA’s decision, a study that SeaGen reported in October had met its primary goal. Patients who received tucatinib and the chemo drugs were 46 percent less likely to see their cancer grow, spread, or to die, compared with patients who received only the pair of chemotherapies. Nearly half of the patients enrolled had seen their cancer spread to the brain; among the patients in that group who received the investigational treatment, the reduction was 52 percent.

About one-fourth of the patients in the trial experienced serious side effects. The drug’s label warns clinicians to watch for severe diarrhea, liver damage, and advises that it may cause harm to a developing fetus.

The drug is the first approved under a new FDA program known as Project Orbis, which provides a framework for concurrent submission and review of oncology drug applications by the agency and its international partners. Regulators in Australia, Canada, Singapore, and Switzerland are also reviewing the treatment. The application was also part of an FDA pilot program called Real-Time Oncology Review, which streamlines data submission ahead of the entire application’s review.

SeaGen co-founder and CEO Clay Siegall, speaking on the conference call, noted the review was the company’s second product to get the FDA’s OK on an expedited basis. The drug will be the third from the company to reach market. Its first, a treatment for lymphomas, was cleared in 2011; the second, a bladder cancer drug, late last year.