Encouraging Results from Pfizer's Palbociclib - Analyst Blog

Pfizer Inc. PFE announced positive detailed results from the phase II PALOMA-1 study on its oncology candidate, palbociclib. The study evaluated post-menopausal women suffering from estrogen receptor positive (ER+), human epidermal growth factor receptor 2 negative (HER2-) locally advanced or metastatic breast cancer.

Results from the PALOMA-1 study revealed that a combination treatment of palbociclib and Novartis' NVS Femara (letrozole) led to a statistically significant improvement in progression-free survival PFS versus Femara alone in women suffering from breast cancer. Other efficacy endpoints like duration of treatment and clinical benefit rate were also greater in the palbociclib and Femara combination arm.

Results further demonstrated that overall survival rate in the combination arm was superior to the Femara arm. However, at the time of final PFS analysis the overall survival rate was not statistically significant. Pfizer stated in its press release that the palbociclib and Femara combination was generally safe and well-tolerated.

We note that the U.S. Food and Drug Administration (FDA) granted Breakthrough Therapy designation to palbociclib for breast cancer in Apr 2013 on the basis of interim data from the PALOMA-1 study. Pfizer intends to discuss the results of the study with regulatory authorities across the globe, including the FDA, to determine the way forward for the candidate.

Pfizer is currently enrolling patients to evaluate the combination of palbociclib and Femara in the above population in a global phase III trial (PALOMA-2 or study 1008). Another phase III study (PALOMA-3 or study 1023) evaluating palbociclib combined with AstraZeneca's AZN Faslodex (fulvestrant) versus Faslodex plus placebo in women with HR+ and HER2- metastatic breast cancer is underway. The PALOMA-3 study considers those patients whose cancer has progressed after hormonal therapy.

Palbociclib is an important candidate in Pfizer's pipeline. We believe Pfizer's pipeline must deliver since sales of many of its key products are declining due to generic competition.

Pfizer carries a Zacks Rank #3 (Hold). Some better-ranked stocks include Gilead Sciences Inc. GILD. The stock carries a Zacks Rank #1 (Strong Buy).