Efficacy and safety of triplet nivolumab, relatlimab, and ipilimumab (NIVO + RELA + IPI) in advanced melanoma: Results from RELATIVITY-048.

9504 Background: NIVO (anti–PD-1 antibody) is approved as monotherapy and in combination with either RELA (anti–LAG-3 antibody) or IPI (anti–CTLA-4 antibody) for the treatment of patients (pts) with advanced melanoma. RELATIVITY-048 (NCT03459222) is a phase 1/2, nonrandomized trial evaluating immuno-oncology (I-O) triplets, including NIVO + RELA + IPI, for pts with select solid tumors. This analysis from RELATIVITY-048 focused on NIVO + RELA + IPI use in the advanced melanoma cohort and is the first disclosure from the study. Methods: Pts with advanced melanoma were treated with first-line NIVO 480 mg Q4W + RELA 160 mg Q4W + IPI 1 mg/kg Q8W until progression or unacceptable toxicity. Prior neoadjuvant/adjuvant therapy, including I-O agents, was permitted if completed > 6 mo before enrollment. Pts with controlled brain metastases were allowed to enroll. Primary endpoints were safety and confirmed objective response rate (ORR), disease control rate (DCR), and median duration of response (DOR) per investigator. The secondary endpoint was progression-free survival (PFS) per investigator (median and 6-mo/12-mo rates). Exploratory endpoints included overall survival (OS; median and 12-mo/24-mo rates). Results: In total, 46 pts were treated. Median follow-up was 49.4 mo (range, 0.4–55.0; database lock, Nov. 1, 2023). Median age was 61.0 y, 8.7% had cutaneous acral melanoma, 50.0% were BRAF positive, 73.9% were LAG-3 positive (≥ 1%), 26.1% were tumor cell PD-L1 positive (≥ 1%), and 6.5% had received prior adjuvant therapy. Median duration of treatment was 5.0 mo (range, 0.0–49.0). NIVO + RELA + IPI had a confirmed ORR of 58.7% and a 48-mo OS rate of 71.7% (table). Any-grade and grade 3/4 treatment-related adverse events (TRAEs) occurred in 44 pts (95.7%) and 18 pts (39.1%), respectively. Any-grade TRAEs led to treatment discontinuation in 19 pts (41.3%). Deaths due to TRAEs occurred in 2 pts (4.3%; rectal hemorrhage and dyspnea n = 1, immune-mediated myositis n = 1). Conclusions: In RELATIVITY-048, NIVO + RELA + IPI demonstrated encouraging efficacy, with a confirmed ORR of 58.7% and a 48-mo OS rate of 69.1%. There were no new safety signals with NIVO + RELA + IPI, and the safety profile was generally consistent with I-O combinations. Given the small sample size, additional studies are needed to confirm the efficacy and safety of NIVO + RELA + IPI. Clinical trial information: NCT03459222 . Table: see text