Merck has announced that the U.S. Food and Drug Administration (FDA) has approved KEYTRUDA® (pembrolizumab), the company’s anti-PD-1 (programmed death receptor-1) therapy, for the treatment of adult and pediatric patients with refractory classical Hodgkin lymphoma (cHL), or who have relapsed after three or more prior lines of therapy. Under the FDA’s accelerated approval regulations, this indication is approved based on tumor response rate and durability of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials. In refractory or relapsed cHL, KEYTRUDA is approved for use in adult patients at a fixed dose of 200 mg and in pediatric patients at a dose of 2 mg/kg (up to a maximum of 200 mg). KEYTRUDA is administered intravenously every three weeks until disease progression or unacceptable toxicity, or up to 24 months in patients without disease progression.

Immune-mediated adverse reactions occurred with KEYTRUDA including pneumonitis, colitis, hepatitis, endocrinopathies, and nephritis. Based on the severity of the adverse reaction, KEYTRUDA should be withheld or discontinued and corticosteroids administered when appropriate. Immune-mediated complications, including fatal events, occurred in patients with cHL who underwent allogeneic hematopoietic stem cell transplantation (HSCT) after being treated with KEYTRUDA. Follow patients closely for early evidence of transplant-related complications, and intervene promptly. KEYTRUDA can also cause severe or life-threatening infusion-related reactions. Monitor patients for signs and symptoms of infusion-related reactions; for Grade 3 or 4 reactions, stop infusion and permanently discontinue KEYTRUDA (pembrolizumab). Based on its mechanism of action, KEYTRUDA can cause fetal harm when administered to a pregnant woman. Female patients of reproductive potential should be advised of the potential hazard to a fetus. For more information regarding immune-mediated and infusion-related adverse reactions and use in pregnancy, see "Selected Important Safety Information" below.

The approval is based on data in 210 patients from the KEYNOTE-087 trial, which demonstrated an overall response rate (ORR) with KEYTRUDA (200 mg every three weeks) of 69 percent (95% CI: 62, 75) with a complete remission rate (CRR) of 22 percent and a partial remission rate (PRR) of 47 percent. The median follow-up time was 9.4 months. Among the 145 responding patients, the median duration of response was 11.1 months (range 0.0+ to 11.1 months).

"The results from KEYNOTE-087 showed that most patients with relapsed or refractory classical Hodgkin lymphoma responded to treatment with KEYTRUDA, and 22 percent experienced complete remission," said Dr. Roger M. Perlmutter, president, Merck Research Laboratories. "Today’s approval – the first for KEYTRUDA in a hematologic malignancy – reinforces the hope that immunotherapy will prove useful in a wide variety of cancers."

"For the patients with classical Hodgkin lymphoma who are not cured with existing treatments, there are limited options, and treating their disease becomes more challenging," said Dr. Craig Moskowitz, clinical director, division of hematologic oncology, Memorial Sloan Kettering Cancer Center. "This approval is an important step forward in treating these patients, who are generally young and have a particularly poor prognosis, and gives us the opportunity to help patients in their fight against this devastating disease."