Nivolumab vs Nivolumab with Ipilimumab in Recurrent Small-Cell Lung Cancer (SCLC) (CheckMate 032)
CheckMate 032 enrolled patients with advanced small-cell lung cancer (SCLC) who progressed following 1 or more platinum-based chemotherapy regimens. Patients were assigned to receive either nivolumab monotherapy (NIVO) or nivolumab plus ipilimumab combination therapy (NIVO + IPI). Patients were eligible regardless of platinum sensitivity or PD-L1 expression. The primary end point was objective response rate (ORR). Additional end points were duration of response (DOR), overall survival (OS), progression-free survival, safety, and correlation of tumor PD-L1 expression with activity.
A total of 217 patients have enrolled in this study to date, including 96 and 118 patients treated with 1 or 2 or more prior regimens, respectively. In the NIVO + IPI cohort, ORR was 25% (3% complete response, 22% partial response [PR]), 1-year OS was 42%, and 2-year OS was 30%. Median DOR was 11.7 months. In the NIVO cohort, ORR was 11% (11% PR), 1-year OS was 30%, and 2-year OS was 17%. Of note, the proportion of patients with previously treated SCLC whose tumors expressed PD-L1 was substantially lower compared with proportions observed in studies conducted in previously treated non–small-cell lung cancer (16% vs approximately 53% with ≥1% PD-L1 expression, respectively).
Among patients with SCLC, responses to NIVO + IPI were observed regardless of PD-L1 expression. The ORR and median OS results were similar in patients treated with 1 or 2 or more prior regimens.
Discontinuation rates due to treatment-related adverse events were 5% (NIVO) and 11% (NIVO + IPI). Two treatment-related deaths occurred.
Researchers concluded that treatment with NIVO + IPI resulted in durable objective responses among patients with previously treated SCLC. Safety findings for these regimens were consistent with what has been observed in other tumor types. An ongoing expansion of CheckMate 032 is underway to compare NIVO and NIVO + IPI in a larger sample of patients with previously treated SCLC.
Hellman MD, et al. WCLC 2016. Abstract MA 09 05. ID 4397.