1092P Nivolumab plus relatlimab vs nivolumab in previously untreated metastatic or unresectable melanoma: 3-year subgroup analyses from RELATIVITY-047

RELATIVITY-047 demonstrated a statistically significant improvement with nivolumab (NIVO) + relatlimab (RELA) vs NIVO for the primary endpoint of PFS per BICR. At the 3-y follow-up, NIVO + RELA continued to show clinically meaningful benefit vs NIVO for PFS, OS, and ORR per BICR in patients (pts) with previously untreated metastatic or unresectable melanoma. Here we report post hoc subgroup analyses with ∼3 y follow-up.

Pts were randomized 1:1 to receive NIVO 480 mg + RELA 160 mg as a fixed-dose combination or NIVO 480 mg intravenously Q4W. Descriptive post hoc analyses were performed according to baseline (BL) location of metastases (mets; pts could be counted in ≥ 1 category) and no. of mets sites, and by the presence of liver/lung mets (n = 581; mucosal and acral pts were excluded). Efficacy based on BL LDH level and BRAF mutation status was examined in all pts (n = 714).

Median follow-up was 33.8 mo. Efficacy according to BL location/no. of mets sites favored NIVO + RELA vs NIVO in most subgroups (Table). In pts with BL liver mets, PFS and OS were longer with NIVO + RELA vs NIVO (HR [95% CI]: PFS 0.80 [0.53–1.22]; OS 0.59 [0.36–0.97]); ORR was higher (9.4% ORR difference; 95% CI, −7.7 to 25.6). The benefit of NIVO + RELA was similar for pts with BL lung mets. In pts with BL LDH > ULN, PFS and OS were longer with NIVO + RELA vs NIVO (HR [95% CI]: PFS 0.79 [0.59–1.05]; OS 0.78 [0.58–1.05]). PFS and OS also favored NIVO + RELA vs NIVO in BRAF mutant pts (HR [95% CI]: PFS 0.72 [0.54–0.96]; OS 0.75 [0.53–1.07]) and BRAF wild-type pts (HR [95% CI]: PFS 0.84 [0.67–1.06]; OS 0.84 [0.65–1.08]). No new or unexpected safety signals were identified.

With ∼3 y follow-up, efficacy outcomes continued to favor NIVO + RELA vs NIVO in pts with cutaneous nonacral melanoma regardless of BL location/no. of mets sites and in pts with BL liver/lung mets. NIVO + RELA was also favored in pts with LDH > ULN and regardless of BRAF mutation status. Additional analyses will be presented.