The treatment landscape for small cell lung cancer (SCLC) has significantly changed in recent years with the introduction of immunotherapy. The programmed cell death ligand 1 (PD-L1) inhibitors combined with chemotherapy have become the standard of care in the first-line treatment of patients with extensive-stage SCLC. However, the efficacy of programmed cell death 1 (PD-1) inhibitors combined with chemotherapy in this patient population remained unknown until a recent clinical trial, which evaluated the efficacy and safety of the PD-1 inhibitor serplulimab in combination with chemotherapy in patients with extensive-stage SCLC.
The study, known as ASTRUM-005, was an international, double-blind, phase 3 randomized clinical trial conducted at 114 hospital sites in six countries. The trial enrolled 585 patients with extensive-stage SCLC who had not previously received systemic therapy. The patients were randomized to receive either serplulimab or a placebo in combination with intravenous carboplatin and etoposide every three weeks for up to 12 weeks. The study's primary outcome was overall survival, with 13 secondary outcomes, including progression-free survival and adverse events.
The study found that adding serplulimab to chemotherapy improved overall survival compared to chemotherapy alone. Patients who received serplulimab lived for an average of 15.4 months, while those who received a placebo lived for 10.9 months. This difference was significant, with a very low probability of it happening by chance. Patients who received serplulimab also had longer progression-free survival than those who received a placebo.