1808P - Immunotherapy retreatment with serplulimab versus chemotherapy in extensive-stage advanced small cell lung cancer previously treated with first-line immunotherapy: A real-world retrospective cohort study

Background

An optimal strategy for second-line treatment in ES-SCLC is undetermined, especially in those previously given immunotherapy. This study aims to evaluate the real-world efficacy and safety of immunotherapy retreatment using a PD-1 inhibitor, serplulimab, versus chemotherapy in ES-SCLC after first-line immunotherapy using PD-L1 inhibitors.

Methods

This study included patients with ES-SCLC who experienced progressive disease or discontinuation due to safety after receiving first-line PD-L1 inhibitors combined with chemotherapy from January 2019 to May 2023. Patients who received other immunotherapy drugs during second-line treatment were excluded. In accordance with the second-line treatment, patients were divided into serplulimab and chemotherapy groups. The former group consisted of patients who received serplulimab, either monotherapy or combination therapy, while the latter group comprised patients who underwent other treatment, such as chemotherapy, angiogenesis drugs and radiotherapy. The outcomes included progression-free survival (PFS), objective response rate (ORR), and safety.

Results

This study included 160 patients, of whom 67 were exposed to serplulimab and 93 were exposed to chemotherapy. The reason for discontinuation of first-line immunotherapy was mostly secondary resistance (n=148, 92.5%). The date of the last follow-up was 24 April 2024. PFS was prolonged with serplulimab compared with chemotherapy (median 7.61 vs. 5.60 months, HR 0.251, 95% CI 0.140-0.450, P<0.001), with a comparable ORR (53.7% vs. 40.9%, P=0.107). Multivariate Cox regression analysis showed an independent association of second-line serplulimab with prolonged PFS, without any link to first-line immunotherapy. In combination of angiogenesis drugs, Grade ≥3 adverse effects occurred in 17.5% and 16.4% of the patients with serplulimab and chemotherapy, respectively.

Conclusions

In patients with ES-SCLC with disease progression after first-line immunotherapy, immunotherapy retreatment with serplulimab was associated with significantly prolonged PFS compared with chemotherapy, with similar safety profile.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

C. Liu.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.