Dr. Liu on the CheckMate-032 Trial in SCLC

Stephen Liu, MD, associate professor of medicine, Division of Hematology and Oncology, Georgetown University Medical Center, discusses the CheckMate-032 trial in small cell lung cancer (SCLC).

The CheckMate-032 trial had several cohorts, one of which is focused on SCLC. This nonrandomized study examined nivolumab (Opdivo) monotherapy versus nivolumab plus ipilimumab (Yervoy) looking at different doses and schedules. The initial nonrandomized cohort showed that nivolumab alone offers a response rate of 10%, but adding ipilimumab increases it to 20%; however, the rate for grade ≥3 adverse events (AEs) also increases. In both arms, the median progression-free survival was poor but landmark survival rates were impressive, according to Liu. When the cohort of patients who received nivolumab monotherapy in the third-line setting is removed, there are modest response rates, but responses are durable and led to the accelerated FDA approval of nivolumab in this setting in August 2018, explains Liu.

Later, the CheckMate-032 trial added a randomized cohort still looking at nivolumab alone versus nivolumab with ipilimumab and continued to show similar results. The response rate for nivolumab monotherapy was 12% and doubled with the addition of ipilimumab, but the number of grade 3/4 AEs tripled, says Liu. Additionally, adding a high dose of ipilimumab did not increase survival. Liu is not advocating for high doses of ipilimumab in this patient population but believes lower doses of ipilimumab may yield better results.