Nivolumab vs investigator's choice (IC) in patients with recurrent or metastatic (R/M) squamous cell carcinoma of the head and neck (SCCHN): Treatment effect on clinical outcomes by best overall response in checkmate 141

Background: In CheckMate 141, nivolumab monotherapy significantly prolonged overall survival (OS) vs IC (median [95% CI]: 7.5 [5.5, 9.1]mo vs 5.1 [4.0, 6.0]mo) and doubled response rate (13.3% vs 5.8%) in patients (pts) with R/M SCCHN. Here, we describe clinical outcomes by best overall response for the nivolumab and IC arms. Methods: CheckMate 141 (NCT02105636) was a randomized, open‐label, phase 3 trial in which pts (N=361) with R/M SCCHN who progressed on or within 6 mo of platinum‐based therapy were randomized 2:1 to nivolumab 3 mg/kg every 2 weeks (n=240) or IC of methotrexate, docetaxel, or cetuximab (n=121). We analyzed the primary endpoint of OS and additional endpoint of safety by best overall response (complete or partial response [CR/PR], stable disease [SD], or progressive disease [PD]), assessed by investigators per RECIST 1.1 every 6 weeks beginning at week 9. Results: The minimum follow‐up was 11.4mo. Baseline demographics were similar across response groups and treatment arms. Median duration of therapy for nivolumab‐treated pts with CR/PR, SD, and PD was 12.5 mo, 4.2 mo, and 1.6 mo, respectively. Estimates of median OS, 12‐mo, and 18‐mo survival rates favored nivolumab vs IC in the CR/PR and SD response groups (Table). The incidence of grade 3‐4 treatment‐related adverse events was lower for nivolumab vs IC within each of the response groups (CR/PR, SD, and PD). Conclusions: Pts with CR/PR and SD had improved median OS and survival rates with nivolumab relative to single‐agent standard therapy. Nivolumab's safety profile was favorable vs IC, including for pts with CR/PR whose median duration of therapy was greater than a year. (Table Presented).