Adebrelimab plus chemotherapy improves overall survival in extensive-stage small-cell lung cancer

1. The adebrelimab group had an improved overall survival, higher objective response rate and an increased progression-free survival.

2. Adverse events were similar in both groups, with the most common treatment-related grade 3 or 4 ones being decreased neutrophil count, decreased white blood cell count, anemia, and decreased platelet count.

Evidence Rating Level: 1 (Excellent)

Study Rundown: While current treatment frameworks for extensive-stage small-cell lung cancer (ES-SCLC) tend to involve immunotherapy, various agents have shown different efficacy outcomes. This study explored the use of adebrelimab (a novel humanized IgG4 monoclonal antibody against PD-L1) on patients with untreated ES-SCLC. Patients were randomly assigned to receive carboplatin and etoposide, with either adebrelimab or placebo. In the adebrelimab group, there was an increased median overall survival (OS), increased progression-free survival (PFS) rates, and higher objective response rates (ORR). Treatment-related adverse events of grade 3 or 4 occurred with similar frequency in both groups, with the most common category being hematological events such as decreased neutrophil count, decreased white blood cell count, anemia, and decreased platelet count. Occurrence of treatment-related serious adverse events was slightly higher in the adebrelimab group. Limitations to this study include its generalizability as it only included patients from China, and that it only used one biomarker for survival. The strength of this study is that it provides a treatment option to ES-SCLC patients, which currently have a poor prognosis and limited treatment options. Overall, this study showed the clinical benefits of adebrelimab and supports its viability as a first-line treatment option.

Click to read the study in The Lancet Oncology

Relevant Reading: Small cell lung cancer (SCLC): no treatment advances in recent years

In-Depth [randomized control trial]: This multicenter phase III trial was done in 47 tertiary hospitals in China. Patients were randomly assigned to receive carboplatin and etoposide, with either adebrelimab or placebo; 230 were in the adebrelimab group and 232 were in the placebo group. Median OS was 15.3 months in the adebrelimab group and 12.8 months in the placebo group (hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.58 to 0.90; P=0.0017). PFS rate at 6 and 12 months in the adebrelimab group was 49.4% (95% CI, 42.4 to 56.0) and 19.7% (14.5 to 25.5), respectively, compared to 37.3% (30.7 to 43.9) and 5.9% (3.1 to 10.1) in the placebo group, respectively. The proportion of patients with an ORR in the adebrelimab group was 70.4% (95% CI, 64.1 to 76.3) and 65.9% (59.5 to 72.0) in the placebo group. Treatment-related grade 3 or worse adverse events occurred in 86% and 85% of patients in the adebrelimab and placebo groups, respectively. The most common adverse events across both groups were decreased neutrophil count (76% in the adebrelimab group and 75% in the placebo group), decreased white blood cell count (46% and 38%, respectively), decreased platelet count (38% and 34%, respectively), and anemia (28% and 28%, respectively). Occurrence of treatment-related serious adverse events was 39% and 28% in adebrelimab and placebo groups, respectively. Frequency of hematological adverse events was higher across both groups when indirectly compared to other immunochemotherapy agents, though this may be attributed to a higher susceptibility to such events from chemotherapy in Asian patients. Overall, adebrelimab plus chemotherapy significantly improved overall survival and showed an acceptable safety profile in ES-SCLC patients.

Image: PD

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