FDA Approves Adjuvant Pembrolizumab for Stage IIB or IIC Melanoma Following CR

The FDA has approved pembrolizumab (Keytruda) for the adjuvant treatment of adult and pediatric patients with stage IIB or IIC melanoma following complete resection (CR).

The regulatory agency also expanded the indication for the immunotherapy for adjuvant use in patients with stage III melanoma following CR to include pediatric patients aged 12 yers and older.

The indication for the agent's use in patients with stage IIB and IIC melanoma is based on findings from the first interim analysis of the phase 3 KEYNOTE-716 trial (NCT03553836), in which pembrolizumab resulted in a statistically significant improvement in recurrence-free survival (RFS), reducing the risk of disease recurrence or death by 35% (HR = 0.65; 95% CI, 0.46-0.92; P = .0132) vs placebo. Specifically, the median RFS was not reached in either treatment arm.

After a median follow-up of 14.4 months, 11% (n = 54/487) of patients who received the immunotherapy experienced a recurrence or died vs 17% (n = 82/489) of those who were given placebo.

Efficacy in pediatric patients, aged 12 years and older, who had stage IIB, IIC and III melanoma is supported by extrapolation of efficacy findings from adults, given similar biology, pharmacology of drug effect, as well as similar exposure-response for efficacy and safety.

“The standard of care for patients with resected stage IIB and IIC melanoma has been observation, despite the fact that for these patients, the risk of recurrence is nearly the same as for patients with later-stage disease for whom treatment is recommended,” Jason Luke, MD, director, Cancer Immunotherapeutics Center at UPMC Hillman Cancer Center, stated in a press release. “Today’s approval of pembrolizumab for the adjuvant treatment of patients 12 years and older with stage IIB and IIC melanoma following complete resection is an important advance that provides these patients with a new option that can help reduce the risk of their cancer returning.”

The multicenter, double-blind, placebo-controlled phase 3 trial enrolled a total of 976 patients with completely resected stage IIB or IIC melanoma. Study participants were randomized to receive 200 mg of pembrolizumab or the pediatric dose of 2 mg/kg every 3 weeks or placebo for up to 1 year until either recurrence or intolerable toxicity. Patients were stratified based on AJCC eighth edition T Stage (> 2.0-4.0 mm with ulceration vs > 4.0 mm without ulceration vs > 4.0 mm with ulceration).

The main efficacy outcome measure for the trial was investigator-assessed RFS.

Regarding safety, adverse effects that were reported in those with stage IIB or IIC melanoma were comparable to those reported in 1011 patients with stage III melanoma from the phase 3 KEYNOTE-054 trial (NCT02362594) or the 2799 patients with melanoma or non–small cell lung cancer treated with the immunotherapy as a monotherapy.

Reference

1. FDA approves Merck's KEYTRUDA (pembrolizumab) as adjuvant treatemnt for adult and pediatric (≥12 years of age) patients with stage IIB or IIC melanoma following complete resection. News release. Merck; December 3, 2021. Accessed December 3, 2021. https://bit.ly/3DrqYal