Adjuvant therapy with nivolumab versus ipilimumab after complete resection of stage III/IV melanoma: Updated results from a phase 3 trial (CheckMate 238)

9502Background: In the initial report of data from CheckMate 238, at a minimum follow-up of 18 mo, NIVO demonstrated significantly longer recurrence-free survival (RFS) vs IPI in patients (pts) with resected stage III or IV melanoma. Here, we report updated efficacy results from this phase III study with an additional 6 mo of follow-up. Methods: Eligible pts included those ≥15 yrs of age who underwent complete resection of stage IIIB/C or IV melanoma. 906 pts were randomized 1:1 (stratified by disease stage and PD-L1 status at a 5% cutoff) to receive NIVO 3 mg/kg Q2W (N=453) or IPI 10 mg/kg Q3W for 4 doses, then Q12W (from week 24) (N=453) for up to 1 yr, or until disease recurrence or unacceptable toxicity. The primary endpoint was RFS; distant metastasis-free survival (DMFS) in pts with stage III disease was an exploratory endpoint. Results: At a minimum follow-up of 24 mo, RFS continued to be significantly longer for NIVO vs IPI (hazard ratio 0.66, Pu003c0.0001), with 171/453 and 221/453 events, respective...