Efficacy of Immune Checkpoint Inhibitors in Combination With Platinum-Based Doublet Chemotherapy for Extensive-Stage Small-Cell Lung Cancer Patients With Eastern Cooperative Oncology Group-Performance Status 2-3: A Single-Institution Retrospective Study.

BACKGROUND

The prognosis of small-cell lung cancer (SCLC) remains poor, particularly in patients with extensive-stage SCLC. The IMpower133 and CASPIAN trials revealed the efficacy of immune checkpoint inhibitors (ICIs) in extensive-stage SCLC patients with good performance status (PS). The aim of this study was to investigate the efficacy of ICIs in patients with poor PS.

PATIENTS AND METHODS

Patients with extensive-stage SCLC who visited Saitama Medical Center, Saitama Medical University (Kawagoe, Japan) (September 2019-December 2022) were enrolled and followed up until February 2024. Objective response rate (ORR) and overall survival (OS) were compared between patients who received platinum-based doublet chemotherapy with an ICI (atezolizumab or durvalumab; ICI group) and those treated with platinum-based doublet chemotherapy alone (non-ICI group). Results were stratified by the Eastern Cooperative Oncology Group performance status (ECOG-PS) (i.e., 0-1 and 2-3).

RESULTS

A total of 74 patients were included in the study (median OS: 327 days). In patients with ECOG-PS 0-1, ORR was 76.5% and 56.5% in the ICI group (n = 17) and non-ICI group (n = 23), respectively; OS was 406 and 379 days, respectively. In patients with ECOG-PS 2-3, ORR was 93.3% and 56.3% in the ICI group (n = 15) and non-ICI group (n = 16), respectively; OS was 446 days and 169 days, respectively. This evidence indicates that the addition of an ICI significantly improved OS (p = 0.00661) and enhanced ORR.

CONCLUSION

In patients with extensive-stage SCLC and ECOG-PS 2-3, the addition of atezolizumab or durvalumab to platinum-doublet chemotherapies improved the ORR, resulting in a better prognosis. These findings suggest that chemoimmunotherapy may be a feasible treatment option beyond the ideal clinical trial populations, addressing an unmet clinical need.