OBJECTIVES : In the global, double-blind, randomized Phase 3 CM-577 trial involving patients with resected EC/GEJC previously treated with neoadjuvant chemoradiotherapy, adjuvant nivolumab therapy was associated with improvement in disease-free survival, similar quality of life relative to placebo, and was well tolerated. This study examined the HCRU of patients during adjuvant treatment with nivolumab versus placebo in CM-577.

METHODS : Data on hospital admissions and non-protocol-specified visits (NPSVs)—the latter defined as hospital outpatient, emergency room, physician office, home healthcare, or other visits—were collected from all 794 randomized CM-577 participants during treatment (patients treated for one year or until disease progression). Frequency and duration of hospital admissions and NPSVs were summarized and exposure-adjusted analysis of hospitalizations, including calculation of exposure-adjusted incidence rate ratio (IRRs) for reduction of incidence with nivolumab versus placebo, was completed by modelling events using negative binomial regression accounting for treatment duration as an offset variable.

RESULTS : During treatment, 25% of patients on nivolumab and 28% of patients on placebo experienced at least one hospitalization, with 18% (nivolumab) and 22% (placebo) experiencing a single hospitalization. Median length of hospitalization was 8 and 6 days for nivolumab and placebo, respectively. Average treatment exposure was similar in each arm; adjusting for treatment exposure, the incidence of hospital admission was similar for patients treated with nivolumab versus placebo (0.78 versus 0.69 admissions/patient/year; IRR=1.12 [95% CI 0.78, 1.62]). Frequency of NPSV was similar between treatment arms (nivolumab 33%; placebo 32%), with <20% of patients in each arm requiring >1 NPSV. The most common types of NPSVs in both arms were hospital outpatient and physician office visits.

CONCLUSIONS : In CM-577, patients with EC/GEJC receiving adjuvant nivolumab treatment did not have significantly higher HCRU than patients receiving placebo. These findings further support clinical data to demonstrate treatment benefit and tolerability for adjuvant nivolumab in patients with resected EC/GEJC.