FDA D.I.S.C.O. Burst Edition: FDA approval of Zynyz (retifanlimab-dlwr) for metastatic or recurrent locally advanced Merkel cell carcinoma
Regulatory approval: On March 22, 2023, the US FDA granted accelerated approval to retifanlimab-dlwr (Zynyz) for adult patients with metastatic or recurrent locally advanced Merkel cell carcinoma. The decision was based on PODIUM-201, an open-label, multiregional, single-arm study in 65 previously untreated patients with advanced disease. Independent central review reported an objective response rate of 52% (18% complete responses), with durable responses observed in subsets at ≥6 and ≥12 months.
FDA regulatory approval
On March 22, 2023, the FDA granted accelerated approval to retifanlimab-dlwr (Zynyz) for adult patients with metastatic or recurrent locally advanced Merkel cell carcinoma.
Supporting evidence
Safety and efficacy were evaluated in PODIUM-201, an open-label, multiregional, single-arm study of 65 patients with metastatic or recurrent locally advanced Merkel cell carcinoma who had not received prior systemic therapy for advanced disease.
Key efficacy endpoints were objective response rate (ORR) and duration of response (DOR), assessed by an independent central review committee per RECIST v1.1:
- ORR: 52%
- Complete response rate: 18%
- DOR: 26 patients had DOR ≥6 months; 21 patients had DOR ≥12 months
Safety
The safety population included 105 patients with Merkel cell carcinoma. The most common adverse reactions (>10%) were fatigue, musculoskeletal pain, pruritus, diarrhea, rash, pyrexia, and nausea. Serious adverse reactions occurred in 22% of patients receiving retifanlimab-dlwr.
The FDA review used an Assessment Aid, described as a voluntary submission from the applicant to facilitate assessment.