Adverse events limited the dose intensity or schedule of chemotherapy when added to nivolumab in patients with treatment-naive advanced gastric cancer, according to results from a small, phase 2 trial.
Fully 95% of patients delayed or reduced the dose of chemotherapy because of adverse events. Serious (grade 3 or higher) treatment-related adverse events affected 15% of patients and 13% of patients stopped treatment because of adverse events, said, of National Cancer Center Hospital in Tokyo, together with his associates. The findings were published in .
Nivolumab (Opdivo) is not approved for treating gastric cancer in the United States but is approved as third-line or later therapy in several other countries. In the phase 2 ATTRACTION-4 trial, 39 patients with previously untreated, unresectable, advanced, or recurrent gastric or gastroesophageal junction cancer received nivolumab (360 mg intravenously every 3 weeks), plus either S-1 (40 mg/m2 orally twice daily for 14 days followed by 7 days off) or capecitabine (1000 mg/m2 orally twice daily for 14 days followed by 7 days off), plus oxaliplatin (130 mg/m2 intravenously on day 1 every 3 weeks).
For the regimen containing S-1, the most common serious adverse events requiring delays or reductions in chemotherapy were thrombocytopenia (57%), neutropenia (48%), and nausea (19%), followed by diarrhea, vomiting, abdominal pain, peripheral sensory neuropathy, and fatigue (14% each). For the regimen containing capecitabine, the most common of these adverse events were neutropenia (44%), decreased appetite (28%), and palmar-plantar erythrodysesthesia syndrome (22%), followed by nausea, vomiting, diarrhea, and peripheral sensory neuropathy (17% each). There were no treatment-related deaths.
Efficacy endpoints were secondary and limited by small sample size. Nonetheless, regardless of which of the two chemotherapy regimens patients received, about two-thirds had a complete or partial treatment response, which is “numerically higher” than that reported for either chemotherapy regimen alone, the researchers wrote. After a median follow-up of 13.2 months, median overall survival was not reached, while median progression-free survival was 9.7 months for the S-1-based regimen and 10.6 months for the capecitabine-based regimen. Antitumor response appeared to be unrelated to programmed death–ligand 1 status.
Based on the findings, both nivolumab-chemotherapy regimens have “manageable safety profile and clinically relevant antitumor profile,” Dr. Boku and his coinvestigators stated. The second part of ATTRACTION-4 has recruited a larger group of patients and should shed more light on efficacy.
Ono Pharmaceutical and Bristol-Myers Squibb funded the work. Dr. Boku reported financial ties to both companies and to AstraZeneca and Chugai Pharmaceutical.
SOURCE: Boku N et al. Ann Oncol. 2018 Dec 19.