Pfizer nabs a fast FDA review for breast cancer pipeline star palbociclib

Pfizer Oncology President Garry Nicholson

Pfizer ($PFE) has picked up a priority review designation for its closely watched cancer drug palbociclib, potentially slicing four months off the review timeline for a therapy that is being hustled along at an accelerated rate.

The pharma giant, which has been plagued by a thin pipeline after undergoing major R&D deconstructive surgery in recent years, has a lot riding on this one. Pfizer decided to lunge for an approval for palbociclib on Phase II data at the urging of a number of analysts excited by the blockbuster potential of this drug. Peak sales estimates typically range around $3 billion a year--which would be a big boost to Pfizer.

The CDK 4/6 inhibitor has already won breakthrough drug status at the FDA. The PDUFA date for palbociclib will fall on April 13, 2015, as Pfizer seeks an OK to market it for women with advanced or metastatic ER+, HER2- breast cancer.

Pfizer is racing to an approval in hopes of gaining a head start on Novartis ($NVS) and Eli Lilly ($LLY), both of which have their own CDK drugs in the late-stage pipeline. LEE011 from Novartis should be ready in 2016 and Lilly may file bemaciclib a year later.

Back in the spring Pfizer reported that the drug doubled the average amount of progression-free survival (PFS) time among patients with advanced breast cancer. But in the first detailed glimpse of its impact on overall survival (OS)--a key feature to the future prospects of this flagship program--the therapy had so far failed to demonstrate a statistically significant improvement in extending patients' lives after an initial assessment.

"This acceptance has been expected and clears some of the risks of the program as some investors started to consider the scenario in which phase 3 results would be needed," noted ISI analyst Mark Schoenebaum, who's followed the drug closely.

Adds the analyst: "An interesting data point from the academic literature about historical approval rates for FDA filings that were granted priority review status: first-cycle approval rates were 72 of 106 (67.9%) for applications granted a priority review and 79 of 196 (40.3%) for drugs given a standard review."

"If approved as a first-line therapy in combination with letrozole, palbociclib will be an important new option for the thousands of women in the U.S. who are living with metastatic breast cancer," said Garry Nicholson, president, Pfizer Oncology. "We look forward to continuing to work closely with the FDA through the review process."

- here's the release