Nivolumab alone or in combination with ipilimumab met multiple endpoints against metastatic or locally advanced chemotherapy-refractory esophagogastric cancer in the recent phase 1/2trial, thereby opening doors to a future phase 3 trial.
The agents demonstrated “clinically meaningful antitumor activity,” reported, of Memorial Sloan Kettering Cancer Center, New York, and her coauthors.
After the 2017trial demonstrated improved survival rates, “nivolumab was approved in Japan for the treatment of patients with chemotherapy-refractory gastric and gastroesophageal junction [GEJ] cancers regardless of programmed death-ligand 1 [PD-L1] status,” the authors wrote in the .
Nivolumab is a checkpoint inhibitor, like pembrolizumab, which “was approved for the treatment of patients with chemotherapy-refractory PD-L1–positive gastric/GEJ cancer on the basis of the promising clinical activity observed in thetrial,” the authors noted. Testing nivolumab in a Western population would therefore build on these previous trials. Combining nivolumab, a PD-l inhibitor, with ipilimumab, a monoclonal antibody targeting cytotoxic T-lymphocyte antigen 4, was based on “synergistic activity” reported in preclinical models, the authors wrote.
Results from the ongoing CheckMate-032 trial included 160 patients with metastatic or locally advanced chemotherapy-refractory esophageal, gastric, or gastroesophageal junction cancer treated at centers in Europe and the United States. Just under 80% of patients had received two or more prior therapies.
In the present trial, patients were given one of three treatment regimens: nivolumab 3 mg/kg every 2 weeks, nivolumab 1 mg/kg plus ipilimumab 3 mg/kg every 3 weeks for four cycles (NIVO1 + IPI3), or nivolumab 3 mg/kg plus ipilimumab 1 mg/kg every 3 weeks for four cycles (NIVO3 + IPI1). The primary endpoint was objective response rate (ORR). Secondary endpoints included 12-month progression-free survival and 12-month overall survival (OS).
Patients in the NIVO1 + IPI3 group achieved the best ORR (24%) and 12-month progression-free survival (17%) and also showed a promising 12-month OS (35%), second only to nivolumab monotherapy (39%). PD-L1 status was not predictive of treatment response.
Although NIVO1 + IPI3 was the most clinically effective, almost half (47%) of these patients also had grade 3 or higher adverse events, compared with more favorable rates of 17% and 27% for nivolumab monotherapy and NIVO3 + IPI1, respectively.
Still, the authors concluded, “on the basis of the numerically higher overall response and landmark OS rates in the NIVO1 + IPI3 arm, this combination was considered more likely to offer clinical benefit relative to currently available treatment regimens for first-line metastatic esophagogastric cancer and was selected for further evaluation in the phase 3study (NCT02872116).” This trial, along with another to investigate nivolumab in the adjuvant setting ( ), are ongoing.
CheckMate-032 was supported by Bristol-Myers Squibb. The authors also reported funding from Merck, Incyte, Gilead Sciences, and others.
SOURCE: Janjigian YY et al. J Clin Oncol. 2018 Aug 15. .