No Deaths Observed Related to Nivolumab in Resected Gastric Cancers

No nivolumab (Opdivo)-related deaths were observed among patients with resected esophageal or gastroesophageal junction cancer previously treated with chemoradiation in the phase 3 CheckMate 577 study (NCT02743494), according to Ronan J. Kelly, MD, MBA.

Kelly, director of oncology at the Charles A. Sammons Cancer Center and W.W. Caruth, Jr. Endowed Chair of Immunology at Baylor University Medical Center in Dallas, Texas, spoke with CancerNetwork® about efficacy findings from the phase 3 study as well as key findings regarding patient characteristics and safety insights. He exhibited findings from the study in an oral presentation he gave at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting.

He began by describing the baseline characteristics for patients enrolled in the trial, explaining that most patients had esophageal cancer and that the most common histology was adenocarcinoma. He further remarked that most patients had node-positive disease, a poor prognostic factor, as well as histologically “hot” tumors, or ones with a PD-L1 combined positive score (CPS) of 1 or greater.

Kelly then described findings from the trial, highlighting that all patients had concluded therapy, with nearly half successfully completing treatment. He further expressed that disease progression occurred at a greater rate among patients treated with placebo vs nivolumab, with both arms experiencing a similar duration of treatment and number of doses. He concluded by explaining that more deaths occurred in the placebo arm vs the nivolumab arm and that no deaths were observed that were attributable to nivolumab treatment.

Transcript

The [phase 3 CheckMate 577] data that we showed at the ASCO Annual Meeting had a data cutoff [date of] November 7, 2024. The median follow-up time was 78.3 months, and the minimum follow-up was 5 years. In terms of the baseline characteristics for patients who [were enrolled] in the study, the salient points are that [regarding] tumor location, 59% had esophageal cancer and 41% had gastroesophageal junction cancer. Adenocarcinoma was the predominant histology, with 71% of patients having adenocarcinoma [and] 29% having squamous cell carcinoma.

The poor prognostic factor of lymph node–positive disease occurred in 58% of the patients. And then we looked at PD-L1, broken down into both TPS [tumor proportion score] and CPS, and we know in this disease setting CPS is now the better assessment of PD-L1 status. Here, for the first time, we’ve shown that approximately 10% of patients had immunologically cold tumors defined as a CPS of less than 1 and the remaining patients had [a CPS of] greater than 1, or immunologically hotter tumors, so that was also interesting information.

In terms of exposure and disposition, there were no patients currently on treatment with the study drug. Forty-nine percent completed treatment, and then if we look at those who discontinued treatment, 29% [experienced] disease progression in the nivolumab arm whereas 44% [experienced] disease progression in the placebo arm. The median duration of treatment and the median number of doses were similar across both arms. In terms of death, we [observed] more deaths due to disease progression [with] placebo vs the nivolumab arm and there were no [nivolumab-related] treatment deaths.

Reference

Kelly RJ, Ajani JA, Kuzdzal J, et al. Adjuvant nivolumab in resected esophageal or gastroesophageal junction cancer (EC/GEJC) following neoadjuvant chemoradiotherapy (CRT): first results of overall survival (OS) from CheckMate 577. J Clin Oncol. 2025;43(suppl 16):4000. doi:10.1200/JCO.2025.43.16_suppl.4000