FDA Approves Retifanlimab for Adults With Advanced Merkel Cell Carcinoma

The FDA has granted accelerated approval to retifanlimab (Zynyz) for the treatment of adults with metastatic or recurrent locally advanced Merkel cell carcinoma (MCC).¹

“More than a third of patients with MCC present with regional or distant metastases, which are associated with high rates of mortality,” said DShailender Bhatia, MD, University of Washington and Fred Hutchinson Cancer Center, 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, and I look forward to having Zynyz in our treatment portfolio for these difficult-to-treat patients.”

Approval of retifanlimab for this indication was granted based on results from the phase 1 POD1UM-201 trial (NCT03599713). In 65 patients with metastatic or recurrent locally advanced MCC, retifanlimab achieved an overall response rate (ORR) of 2% (95% CI, 40-65). Responses to retifanlimab included 12 complete responses (18%), and 22 partial responses (34%).

The duration of response (DOR) of retifanlimab in the study ranged from 1.1 to 24.9+ months with 76% of patients having experienced a DOR of 6 months or more, and 62% having had a DOR 12 months or longer.

Twenty-two percent of patients in the study experienced serious adverse reactions. The most frequent adverse reactions occurred in 2% of patients and included fatigue, arrhythmia, and pneumonitis. Eleven percent of patients required permanent treatment discontinuation during the study. The most common adverse events among patients treated with retifanlimab were fatigue, musculoskeletal pain, pruritus, diarrhea, rash, pyrexia, and nausea.

POD1UM-201 is an open-label, multiregional, single-arm study which aims to enroll 107 patients. The study included a cohort of patients who were chemotherapy naïve as well as a cohort that was chemotherapy refractory. In addition to ORR and DOR, these patients were evaluated for the secondary end points of progression-free survival, overall survival, safety determined by the number of patients with treatment-emergent adverse events, and pharmacokinetics.

Patients in POD1UM-201 were treated with retifanlimab 500 mg intravenously every 4 weeks until disease progression, unacceptable toxicity. Treatment could continue for up to 24 months.

“Zynyz offers patients and healthcare professionals an additional first-line anti-PD-1 option for patients with metastatic or recurrent locally advanced MCC, which can be a challenging and aggressive disease to treat,” said Hervé Hoppenot, chief executive officer, Incyte, in the press release.

_REFERENCE:

_{Incyte announces FDA approval of Zynyz™ (retifanlimab-dlwr) for the treatment of metastatic or recurrent locally advanced merkel cell Carcinoma (MCC). News release March 22, 2023. Acccessed March 22, 2023. https://bwnews.pr/40rKNKF}