The U.S. Food and Drug Administration has approved a new treatment for women with advanced (metastatic) breast cancer. The new therapy, palbociclib, will be used to treat postmenopausal women with metastatic estrogen receptor-positive (ER-positive) breast cancer who have not received previous treatment.
Palbociclib, which is marketed under the name Ibrance, will be used in combination with another breast cancer drug, letrozole.
“This is a new class of drugs that has been effective in treating this particular pathway in cancer, and it has improved outcomes for patients with advanced ER-positive breast cancer, one of the most common forms of the disease,” says Harold J. Burstein, MD, PhD, a breast cancer specialist with the Susan F. Smith Center for Women’s Cancers at Dana-Farber.
Palbociclib was tested in a trial of 165 women with ER-positive advanced breast cancer who had not received previous treatment. Patients who were treated with palbociclib and letrozole lived about 20 months without the disease progressing. Women who received just the letrozole lived about 10 months without the disease progressing.
The drug’s effectiveness is also being tested in treating early stage breast cancer, Burstein says.
The FDA approved palbociclib under its accelerated approval program, which allows faster approval of a drug if it is used to treat a serious or life-threatening disease and clinical trial data shows it is likely to benefit patients. The approval was based on a small, randomized phase II study and full approval will depend on results of a phase III trial that has not yet reported data.