First-Line, Fixed-Duration Nivolumab Plus Ipilimumab Followed by Nivolumab in Clinically Diverse Patient Populations With Unresectable Stage III or IV Melanoma: CheckMate 401

Abstract

PURPOSE To address the paucity of data in patients with historically poor outcomes, we conducted the single-arm phase IIIb CheckMate 401 study to evaluate the safety and efficacy of nivolumab plus ipilimumab followed by nivolumab monotherapy in clinically diverse patient populations with advanced melanoma. METHODS Treatment-naive patients with unresectable stage III-IV melanoma received nivolumab 1 mg/kg plus ipilimumab 3 mg/kg once every 3 weeks (four doses) followed by nivolumab 3 mg/kg (240 mg following a protocol amendment) once every 2 weeks for ≤24 months. The primary end point was the incidence of grade 3-5 select treatment-related adverse events (TRAEs). Overall survival (OS) was a secondary end point. Outcomes were evaluated in subgroups defined by Eastern Cooperative Oncology Group performance status (ECOG PS), brain metastasis status, and melanoma subtype. RESULTS In total, 533 patients received at least one dose of study drug. Grade 3-5 select TRAEs affecting the GI (16%), hepatic (15%), endocrine (11%), skin (7%), renal (2%), and pulmonary (1%) systems occurred in the all-treated population; similar incidence rates were observed across all subgroups. At 21.6 months' median follow-up, 24-month OS rates were 63% in the all-treated population, 44% in the ECOG PS 2 subgroup (including patients with cutaneous melanoma only), 71% in the brain metastasis subgroup, 36% in the ocular/uveal melanoma subgroup, and 38% in the mucosal melanoma subgroup. CONCLUSION Nivolumab plus ipilimumab followed by nivolumab monotherapy was tolerable in patients with advanced melanoma and poor prognostic characteristics. Efficacy was similar between the all-treated population and patients with brain metastases. Reduced efficacy was observed in patients with ECOG PS 2, ocular/uveal melanoma, and/or mucosal melanoma, highlighting the continued need for novel treatment options for these difficult-to-treat patients.