FDA approves Zynyz for Merkel cell carcinoma

The Biologics License Application (BLA) for Zynyz for this indication has been approved under accelerated approval by the U.S. FDA based on tumor response rate and duration of response (DOR). Continued approval of Zynyz for this indication may be contingent on verification and description of clinical benefit in confirmatory trials.

The FDA approval was based on data from the POD1UM-201 trial, an open-label, multiregional, single-arm study that evaluated Zynyz in adults with metastatic or recurrent locally advanced MCC who had not received prior systemic therapy for their advanced disease. Among chemotherapy-naïve patients (n=65), Zynyz monotherapy resulted in an objective response rate (ORR) of 52% (95% confidence interval [CI]: 40-65) as determined by independent central review (ICR) using RECIST v1.1. Complete response was seen in 12 patients (18%), and 22 patients (34%) showed partial response. Among the responding patients, the duration of response (DOR) ranged from 1.1 to 24.9+ months, and 76% (26/34) experienced a DOR of six months or longer, and 62% (21/34) experienced a DOR of 12 months or longer by landmark analysis.

Serious adverse reactions occurred in 22% of patients receiving Zynyz. The most frequent serious adverse reactions (at least 2% of patients) were fatigue, arrhythmia and pneumonitis. Permanent discontinuation of Zynyz due to an adverse reaction occurred in 11% of patients. The most common (at least 10%) adverse reactions that occurred in patients receiving Zynyz were fatigue, musculoskeletal pain, pruritus, diarrhea, rash, pyrexia and nausea.