Formal discussant of the CheckMate 274 trial, Michiel S. Van der Heijden, MD, PhD, of the Netherlands Cancer Institute, said it is an “important” study.

“In looking at these results, one should consider the goal of adjuvant therapy in this setting. Is overtreatment of patients cured by surgery justified? Disease-free survival might not translate to an overall survival benefit. It could just mean that recurrence is delayed, and if patients recur, they will have fewer treatment options in the metastatic setting,” Dr. Van der Heijden explained.

Thus far, other adjuvant trials of chemotherapy and immunotherapy have not shown improved overall survival. “The IMvigor010 trial was negative with atezolizumab, but the CheckMate 274 trial is positive, particularly in the PD-L1–positive subgroup,” he noted. “The curves separated early at the first report of trial results, and with just 1 year of therapy, the extended follow-up curves remained stable. The secondary endpoints were in line with the primary endpoint, all favoring nivolumab in both the intent-to-treat and PD-L1–positive analyses,” he continued.

“The subgroup analysis suggests that patients who did not receive neoadjuvant chemotherapy and are cisplatin-eligible may be better off with chemotherapy,” he added, however.

Dr. Van der Heijden’s main concern with Dr. Galsky’s data was that overall survival was not reported. “The number of events should allow an estimate of overall survival. However, this hierarchic analysis and statistical plan calling for the number of events needed to report overall survival seem excessive, and it may take many years to know,” he said.

The take-away point is that the curves for disease-free survival remain separated over time. “The PD-L1–positive subgroup data are very convincing, despite the lack of overall survival data. For a more complete interpretation of trial results, overall survival data are needed for the PD-L1–negative subgroup and for patients who did not get neoadjuvant therapy,” Dr. Van der Heijden said. 

DISCLOSURE: Dr. Van der Heijden reported financial relationships with Bristol Myers Squibb, Roche, AstraZeneca, Janssen, Merck/MSD, Seagen, 4SC, and Pfizer.