Pfizer's drug delays progression in recurrent breast cancer

Pfizer Inc.’s Ibrance more than doubled the time it took for tumors to come back or start growing again in women with advanced breast cancer who’d been previously treated, a result that could expand the drug’s use and delay chemotherapy for many patients.

Ibrance was approved to treat one of the deadliest forms of breast cancer by U.S. regulators in February, more than two months ahead of schedule. At the time it was approved as an initial therapeutic option for women with advanced ER-positive, HER2-negative breast cancer.

In a study of 521 patients whose advanced cancer came back or started growing again after initial treatment, those treated with Ibrance in combination with AstraZeneca Plc’s hormone therapy Faslodex went a median of 9.2 months until their cancer progressed, compared with 3.8 months in the arm that received Faslodex and a placebo.

“We now have information that indicates that Ibrance can substantially delay the time to tumor progression when used in the first-line or second-line setting,” Mace Rothenberg, chief medical officer of Pfizer’s cancer unit, said in a telephone interview.

In April, Pfizer announced it was stopping the trial early because of Ibrance’s effectiveness.

Hormone therapy is currently the standard of care for patients whose disease progresses after initial treatment. The study was funded by Pfizer and is being presented at the American Society of Clinical Oncology’s annual meeting in Chicago.

New York-based Pfizer has estimated Ibrance could be a treatment option in as many as 23,000 women a year in the U.S. Pfizer charges $9,850 for a month’s supply of the drug before any discounts, and widening the drug’s use to women who relapse could add about 30,000 patients, according to the company.

The company will soon begin looking at Ibrance as a treatment for in head and neck and pancreatic cancers, Rothenberg said.