Evaluating the safety and efficacy of combination immune checkpoint inhibitors and chemotherapy treatment in extensive-stage small cell lung cancer.

OBJECTIVE

This research effort was designed to retrospectively analyze the safety and efficacy of immune checkpoint inhibitors (ICIs) deployed in combination with chemotherapy in extensive-stage small cell lung cancer (ES-SCLC).

METHODS

ES-SCLC patients diagnosed at Guangzhou Chest Hospital from January 1, 2018, through June 30, 2022, were divided into two groups: an IEP group (administered ICIs with etoposide and platinum-based chemotherapy) and an EP group (chemotherapy only). Median overall survival (OS) and progression-free survival (PFS) served as the primary endpoints for analysis, while secondary endpoints that were assessed included objective response rate (ORR), 1- and 2-year OS, and safety. Subgroup analyses explored sites of metastatic progression and ICI types.

RESULTS

In total, 102 patients were enrolled, including 33 in the IEP group and 69 in the EP group. The median OS was significantly longer in the IEP group (14.3 vs. 10.8 months, P = 0.028), while the median PFS showed no significant difference (5.9 vs. 5.3 months, P = 0.746). In subgroup analyses, those patients with brain metastases were found to have derived benefit from IEP treatment (median OS 15.9 vs. 8.3 months, hazard ratio [HR], 0.266 [95% CI, 0.087 to 0.817], P = 0.014). The PFS of patients administered PD-L1 inhibitors was longer than that of those administered PD-1 inhibitors (median 7.0 vs. 3.5 months; HR, 0.342 [95% CI, 0.141 to 0.832], P = 0.014). The safety profile of the IEP regimen was favorable, although these patients were more likely to experience immune-related pneumonia (12.1% vs. 1.4%, P = 0.020). Subgroups analyses showed that patients with a history of smoking (HR = 0.54, 95% CI: 0.31-0.94) and brain metastases (HR = 0.27, 95% CI: 0.09-0.82) were more likely to benefit from IEP treatment.

CONCLUSION

The combination of ICIs and chemotherapy can afford better survival outcomes for ES-SCLC patients, especially in individuals suffering from brain metastases, and they should thus be considered as promising first-line treatment options. However, careful management of immune-related adverse events is crucial.