Novel treatment approved for metastatic breast cancer
Novel treatment approved for metastatic breast cancer
3 Feb 2015The FDA has approved Palbociclib (Ibrance) for the treatment of postmenopausal women with advanced breast cancer that is hormone receptor-positive. The approval stipulates the use of Palbociclib in combination with letrozole (Femara) in patients with metastatic breast cancer who have received no prior endocrine therapy.
Previously designated as breakthrough therapy, Palbociclib (marketed by Pfizer) was on the fast track to approval. The drug is medically characterized as a "cyclin dependent kinase (CDK)-4/6 inhibitor", and is the first such compound to be approved in the United States.
Positive but immature clinical results
A randomized clinical trial showed that the combination of Palbociclib and letrozole led to a doubling of median progression-free survival in advanced hormone receptor -positive breast cancer from 10.2 months with letrozole alone to 20.2 months. However, overall survival data remain immature, according to the FDA announcement. Initial data on median survival showed a 4-month improvement with the combination of Palbociclib and letrozole, but the difference did not achieve statistical significance.
In breast cancer and many other types of cancer, activating this inhibitor causes the loss of control over the cell cycle, resulting in the uncontrolled cell growth that typifies cancer. Preclinical studies showed that inhibition of CDK-4/6 by Palbociclib restored the normal cell-cycle process.
“Novel treatment option” according to FDA officials
"The addition of Palbociclib to letrozole provides a novel treatment option to patients diagnosed with metastatic breast cancer," Richard Pazdur, MD, director of the FDA's Office of Hematologic and Oncology Products, said in a statement. The most common adverse events associated with Palbociclib treatment have been neutropenia, leukopenia, fatigue and anemia.
Source: MedPage Today