Among previously untreated patients with extensive-stage small cell lung cancer (SCLC), adding serplulimab to chemotherapy appears to improve outcomes compared with chemotherapy alone, according to research presented at the 2022 ASCO Annual Meeting.
Previous research has shown that antibodies targeting PD-L1 can be effective in extensive-stage SCLC when used in combination with chemotherapy. It was, however, previously unclear whether PD-1-targeting antibodies are similarly likely to yield improved clinical outcomes.
Serplulimab is a novel, humanized antibody targeting PD-1, which has previously shown promise in other settings. For this randomized multicenter phase 3 study (ClinicalTrials.gov Identifier: NCT04063163), researchers aimed to determine whether adding serplulimab to first-line intravenous carboplatin and etoposide improved outcomes among patients with extensive-stage SCLC.
Patients were randomly assigned 2:1 to receive serplulimab at 4.5 mg/kg or placebo, both combined with chemotherapy. The study’s primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), duration of response (DoR), and safety.
Overall, 585 patients were randomly assigned to the serplulimab group (389 patients) or the placebo group (196 patients). Enrollment took place between 2019 and April 2021, and the median follow-up was 12.3 months.
The median OS was 15.4 months in the serplulimab group and 10.9 months in the placebo group (hazard ratio [HR], 0.63; P <.001). Most subgroups saw a benefit with serplulimab, though a benefit was not seen in patients with brain metastases and never-smokers.
The median PFS was significantly improved with serplulimab (5.7 months) compared with placebo (4.3 months; HR, 0.48; P <.001). DoR was also improved in the experimental arm (5.6 vs 3.2 months, respectively; HR, 0.48).
Grade 3 or higher treatment-related adverse events were more common in the serplulimab group (33.2%) than in the placebo group (27.6%). The most common was endocrine disorder (18.3% vs 4.6%, respectively). Three deaths, possibly related to treatment, were noted in the experimental arm, compared with 1 in the placebo arm.
“Serplulimab plus chemotherapy showed consistent benefits,” said study presenter Ying Cheng, MD, of Jilin Cancer Hospital in China. “Long-term efficacy benefits were also observed.”
Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Cheng Y, Han L, Wu L, et al. Serplulimab, a novel anti-PD-1 antibody, plus chemotherapy versus chemotherapy alone as first-line treatment for extensive-stage small-cell lung cancer: An international randomized phase 3 study. Presented at ASCO 2022; June 3-7, 2022. Abstract 8505.