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.
The combination of serplulimab and chemotherapy had a safety profile that was similar to what was expected based on what we know about each treatment. Some patients in both groups experienced treatment-related side effects that were moderate to severe, with a higher percentage in the serplulimab group. However, more patients in the serplulimab group stopped treatment due to side effects than in the placebo group.
The results of this study are significant as they provide evidence of the efficacy of checkpoint inhibitors in the treatment of extensive-stage SCLC. The addition of serplulimab to chemotherapy has significantly improved overall survival, supporting the use of this combination as the first-line treatment for patients with extensive-stage SCLC.
The ASTRUM-005 trial has shown that the addition of serplulimab to chemotherapy significantly improves overall survival in patients with extensive-stage SCLC who have not previously received systemic therapy. The combination has demonstrated a favorable safety profile and should be considered a standard of care in the first-line treatment of this patient population. It is hoped that this study will pave the way for more effective therapies for patients with SCLC and improve their overall survival.