Merck Says Overall Response Rate Of 66% Observed In KEYTRUDA-treated Patients

(RTTNews) - Merck (MRK) announced early study findings demonstrating that KEYTRUDA or pembrolizumab, the company's anti-PD-1 therapy, achieved an overall response rate of 66 percent, as assessed by International Harmonization Project response criteria (n=19/29: 95% CI, 46-82), in transplant-ineligible and failure patients with relapsed/refractory classical Hodgkin Lymphoma or cHL whose disease progressed on or after treatment with brentuximab vedotin.

Complete remission was achieved in 21 percent of patients (n=6/29) in the study. At the time of analysis, 89 percent of responses were ongoing (n=17/19) with the median duration of response not yet reached (range 1+ to 185+ days).

Data from a cohort of the ongoing Phase 1b KEYNOTE-013 study evaluated KEYTRUDA monotherapy at 10 mg/kg every two weeks in patients with relapsed/refractory classical Hodgkin Lymphoma who had progressed on or after treatment with brentuximab vedotin after failure of autologous stem-cell transplant, or who were transplant-ineligible (n=29).

Median time to response was 12 weeks. In the transplant ineligible/refusal patient group, eight patients were ineligible and one patient refused transplant, respectively. The patient who refused transplant achieved a complete remission.

Adverse events were consistent with previously reported safety data for KEYTRUDA. The most common treatment-related adverse events (occurring in greater than or equal to two patients) included hypothyroidism (n=3), pneumonitis (n=3), constipation (n=2), diarrhea (n=2), nausea (n=2), hypercholesterolemia (n=2), hypertriglyceridemia (n=2) and hematuria (n=2). Sixteen patients (55%) experienced at least one treatment-related adverse event of any grade. Grade 3 treatment-related adverse events occurred in a total of three patients and included axillary pain, hypoxia, joint swelling, and pneumonitis. No Grade 4 treatment-related adverse events or treatment-related deaths were reported.

The company said it looks forward to initiating additional studies including a Phase 2 trial in classical Hodgkin Lymphoma in the first half of 2015.