FDA Accelerates Approval to Pfizer's Palbociclib
The cyclin-dependent kinase 4/6 inhibitor for the treatment of metastatic breast cancer was approved more than two months ahead of the prescription drug user fee goal date.
FDA announced on Feb. 3, 2015 that the agency granted accelerated approval to Ibrance (palbociclib) after Pfizer demonstrated through preliminary clinical data that the drug was superior to existing therapies. The drug was approved more than two months ahead of the prescription drug user fee goal date of April 13, 2015.
The cyclin-dependent kinase 4/6 inhibitor for the treatment of metastatic breast cancer will be used in combination with letrozole, a breast cancer medication for postmenopausal women. It is meant for postmenopausal women with ER-positive, HER2-negative advanced breast cancer who are treatment naïve. FDA recommends health professionals monitor complete blood count prior to start of therapy, the beginning of each cycle, and on day 14 of the first two cycles.
"We now have a first-line treatment option that has demonstrated substantial improvement over letrozole alone for postmenopausal women with ER+/HER2- metastatic breast cancer,” said Dr. Mace Rothenberg, senior vice-president of Clinical Development and Medical Affairs and chief medical officer for Pfizer Oncology. “Ibrance represents an important scientific advance, as well as the first medicine in a new class of anti-cancer agents, CDK 4/6 inhibitors, to be approved by the FDA.”
Although there is no available evidence of improved overall survival, in a clinical trial with 165 participants, treatment with Ibrance plus letrozole was associated with 20.2 months of progression-free survival (PFS) compared with approximately 10.2 months of PFS in participants receiving only letrozole. This represents an almost two-fold improvement in survival.
Mark Schoenebaum, MD, analyst at Evercore ISI, says the price of Ibrance is expected to be $9850 per month, which he says is in line with the Evercore's market model. Novartis will likely benefit from the approval announcement, as the treatment profile includes Novartis’ drug letrozole, which goes by the trade name Femara. Schoenebaum also points out that Amgen is expected to receive ~8% royalties on Ibrance sales in addition to milestone payments as a result of their acquisition all of the outstanding shares of Onyx Pharmaceuticals in August 2013.
