Dr. Finn on the Phase III Trial of Palbociclib for Breast Cancer

Richard Finn, MD, Division of Hematology/Oncology at the Jonsson Comprehensive Cancer Center, University of California, Los Angeles, describes the design of a phase III trial looking at palbociclib (PD-0332991) for the treatment of patients with estrogen receptor-positive (ER+) metastatic breast cancer.

Finn said mobilization of a phase III trial began once early robust data was available from the phase II trial. Researchers did not alter the design of the trial much because of the success of the phase II trial, which showed that the best predictive marker was ER+ disease.

The phase III trial will randomize patients 2-to-1 to receive letrozole plus palbociclib (in the same regimen as the phase II trial: 125mg daily for 3 weeks on, 1 week off) or placebo. Unlike the previous trial, the phase III trial will be double-blind and placebo-controlled. The primary endpoint of the trial will be progression-free survival.

Finn notes that the design and patient population is similar to the phase II trial and that accrual is going well.