The Food and Drug Administration has approved the first PI3K inhibitor for the treatment of breast cancer.
The drug, alpelisib (), was approved for use in combination with fulvestrant for men and postmenopausal women who have hormone receptor (HR)–positive, human epidermal growth factor receptor 2 (HER2)–negative, PIK3CA-mutated, advanced or metastatic breast cancer after progression on, or after, an endocrine-based regimen. The approval was announced by the FDA in a .
The agency also approved a diagnostic test – the therascreen PIK3CA RGQ PCR Kit – for detecting the PIK3CA mutation. The approval is based on results from the. In 572 HR-positive, HER2-negative patients with advanced or metastatic breast cancer who progressed after, or during, treatment with an aromatase inhibitor, the addition of alpelisib to fulvestrant significantly improved progression-free survival in patients with PIK3CA mutated tumors.
Median progression-free survival was 5.7 months on fulvestrant plus placebo, versus 11 months with fulvestrant plus alpelisib (hazard ratio for progression or death, 0.65; 95% confidence interval, 0.50-0.85; P less than .001). The results of the trial were recently published in the New England Journal of Medicine ().
In the FDA statement, Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence, noted that alpelisib is the “first PI3K inhibitor to demonstrate a clinically meaningful benefit in treating patients with this type of breast cancer.”
The drug’s application was approved under the Real-Time Oncology Review pilot, which allows the FDA to begin analyzing efficacy and safety databases before a new drug application is even submitted.
The FDA noted that patients should not start treatment on alpelisib if they have a history of severe skin reactions, such as Stevens-Johnson syndrome, erythema multiforme, or toxic epidermal necrolysis.