FDA Grants Accelerated Approval to Zynyz for Merkel Cell Carcinoma

The FDA has issued an accelerated approval to Incyte’s Zynyz (retifanlimab-dlwr) to treat adults with metastatic or recurrent locally advanced Merkel cell carcinoma (MCC). MCC is a rare skin cancer that tends to grow quickly and has a high rate of metastatic disease, leading to a poor prognosis. The estimated five-year overall survival rate is 14% in patients with Merkel cell carcinoma who present with distant metastatic disease. MCC impacts less than 1 per 100,000 people in the United States, but incidence rates are rapidly rising, especially in adults over the age of 65.

Zynyz is a humanized monoclonal antibody targeting programmed death receptor-1 (PD-1). A spokesperson for Incyte said Zynyx will be priced comparable to other agents in the class currently available in the marketplace. The list price for Merck’s Keytruda (pembrolizumab), which is a PD-1 inhibitor that is also approved to treat patients with advanced Merkel cell carcinoma, is $21,367.04 when given every six weeks. Incyte provides patient access and financial assistance through IncyteCARES.

Shailender Bhatia, M.D.

“More than a third of patients with MCC present with regional or distant metastases, which are associated with high rates of mortality,” Shailender Bhatia, M.D., University of Washington and Fred Hutchinson Cancer Center, said in a press release. “The approval of Zynyz offers healthcare providers another first-line treatment option against MCC that can result in durable responses in patients with metastatic disease.”

The biologics license application (BLA) for was issued an accelerated approval based on tumor response rate and duration of response in POD1UM-201, a single-arm study that evaluated Zynyz in adults with metastatic or recurrent locally advanced MCC who had not received prior systemic therapy. Among chemotherapy-naïve patients, Zynyz monotherapy resulted in an objective response rate (ORR) of 52% as determined by independent central review. Complete response was seen in 12 patients (18%), and 22 patients (34%) showed partial response. Among the responding patients, the duration of response ranged from 1.1 to 24.9+ months, and 76% experienced a duration of response of six months or longer, and 62% 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 were fatigue, arrhythmia and pneumonitis. Permanent discontinuation of Zynyz due to an adverse reaction occurred in 11% of patients. The most common adverse reactions that occurred in patients receiving Zynyz were fatigue, musculoskeletal pain, itching skin, diarrhea, rash, fever and nausea.