FDA grants accelerated approval to Ibrance (palbociclib) + letrozole for ER+/HER2- advanced Breast Cancer -Pfizer

Pfizer Inc. announced the FDA has granted accelerated approval of Ibrance (palbociclib), in combination with letrozole, for the treatment of Postmenopausal Women with Estrogen receptor-positive, Human Epidermal Growth Factor Receptor 2-negative (ER+/HER2-) advanced Breast Cancer as initial endocrine-based therapy for their metastatic disease.

This indication is approved under accelerated approval based on progression-free survival (PFS). Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial. The confirmatory Phase III trial, PALOMA-2, is fully enrolled. Ibrance was reviewed and approved under the FDA�s Breakthrough Therapy designation and Priority Review programs. The Ibrance new drug application was based on the final results of the Phase II PALOMA-1 trial. The most frequently reported adverse event for Ibrance plus letrozole in PALOMA-1 was neutropenia.

Comment:Pfizer reported that the drug doubled the average amount of progression-free survival (PFS) time among patients with advanced Breast Cancer. For women treated with the combination of Ibrance plus letrozole, the median PFS was 20.2 months (95% CI: 13.8, 27.5), a substantial improvement compared to the 10.2 months (95% CI: 5.7, 12.6) of PFS in women who received letrozole alone. Overall response rate in patients with measurable disease as assessed by the investigator was higher in the Ibrance plus letrozole compared to the letrozole alone arm (55.4% versus 39.4%).