Pembrolizumab Confers Long-term Survival Benefit in Advanced Melanoma

Four in 10 patients with newly diagnosed and previously treated advanced melanoma were alive 3 years after initiating the programmed cell death 1 (PD-1) inhibitor pembrolizumab, long-term follow-up data that will be presented at the 2016 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, IL, have shown.¹

Pembrolizumab was initially approved by the U.S. Food and Drug Administration in September 2014 under accelerated review for the treatment of patients with advanced melanoma based on findings from the KEYNOTE-001 trial. KEYNOTE-002 and KEYNOTE-006 have also demonstrated a survival benefit with pembrolizumab as compared with chemotherapy or ipilimumab in this treatment setting.

For the phase 1 KEYNOTE-001 trial, researchers enrolled 655 patients diagnosed with advanced melanoma, of which 75% had previously received prior therapies, including ipilimumab. Participants received pembrolizumab at a dose of 2 mg/kg or 10 mg/kg IV every 3 weeks, or 10 mg/kg every 2 weeks, until disease progression or unacceptable toxicity.

Results showed that at a median follow-up of 32 months, the 3-year overall survival rate was 40% overall, and the median overall survival was 24.4 months. Investigators found that the 3-year overall survival rate was 45% among treatment-naïve patients vs 41% among both ipilimumab-treated patients and ipilimumab-naïve patients.

“Advanced melanoma is still a very challenging cancer, which is why it is so remarkable that such a large proportion of patients see a long-term survival benefit from this therapy,” said lead study author Caroline Robert, MD, PhD, Head of the Dermatology Unit at the Institut Gustave-Roussy in Paris, France. “The results of this study further demonstrate the potential for long-term benefit with pembrolizumab.”

Further, a total of 61 (9%) patients discontinued pembrolizumab treatment after achieving a complete response, and 97% remained in remission at the time of this analysis.

In regard to safety, the most common treatment-related adverse events were fatigue (40%), pruritus (28%), and rash (23%). Only 8% of patients discontinued treatment due to pembrolizumab-related toxicity.

“New therapies that block the PD-1 are extending survival for many patients, and for some may offer the prospect of living longer than ever after a diagnosis with advanced melanoma. In a matter of a few years, these therapies have truly transformed the outlook for patients with melanoma and many other hard-to-treat cancers,” said ASCO spokesperson Don S. Dizon, MD, FACP.      

Reference

1. PD-1 inhibitor pembrolizumab provides long-term survival benefit for patients with advanced melanoma [news release]. Alexandria, VA: American Society of Clinical Oncology; May 18, 2016. Accessed May 18, 2016.