In clinical studies, 10-15% of patients treated with anti-PD-1 monotherapies achieved durable CRs. NIVO+IPI resulted in higher response rates, longer progression-free survival (PFS), and improved overall survival (OS) vs IPI alone, but with an increased frequency of adverse events (AEs). Here, we characterized CRs among patients who received NIVO+IPI, NIVO, or IPI alone.
In this post hoc analysis, data were pooled for NIVO+IPI (N=409), NIVO (N=526), and IPI (N=362) from the CheckMate 069 (phase 2), 066 (phase 3), and 067 (phase 3) studies in MEL patients. Minimum duration of follow-up was 24 months (median ~31 months).
In the pooled analysis, the CR rate was 18% for NIVO+IPI, 16% for NIVO, and 4% for IPI, with partial responses (PRs) in 41%, 28%, and 14% of patients, respectively. Among 75 CR patients in the NIVO+IPI cohort, 77% are off treatment and 8% received subsequent systemic therapy; 15% had elevated LDH levels and 32% had M1c disease. Median duration of CR has not been reached, with 84% (63/75) remaining in response. After an additional follow-up of 12 months (from the 1-year initial follow-up), 24/166 patients (14%) with a PR converted to a CR. For CR patients in the NIVO+IPI cohort, 2-year PFS and OS rates were 86% and 92%, respectively. Grade 3-4 treatment-related AEs occurred in 60% of NIVO+IPI-treated patients with a CR, 65% with a PR, and 60% with stable disease; 31%, 36%, and 35%, respectively, led to discontinuation. There were no treatment-related deaths.
MEL patients treated with NIVO+IPI had a high rate of durable CRs, with the majority remaining in response and often not requiring additional treatment. Some patients with a PR convert to a CR over time. Three-year data will be presented.
Reused with permission from the European Society for Medical Oncology. All rights reserved.