A research team of Yonsei Cancer Center (YCC) and Severance Hospital has reaffirmed the efficacy and safety of atezolizumab combined with etoposide and carboplatin as first-line therapy in small cell lung cancer (SCLC) patients. 

The research team, led by YCC Professor Hong Min-hee and Professor Lee Seo-young of the Department of Oncology at Severance Hospital, said its study results demonstrated that existing first-line treatment for extensive-stage SCLC showed efficacy regardless of patients’ heterogeneity.

Lung cancer is one of the most frequently diagnosed malignancies worldwide and the leading cause of death. Patients with small-cell lung cancer showed a particularly high mortality rate due to its high malignancy. Still, the treatment methods have not been developed much other than chemotherapies as they only accounted for about 15 percent of all lung cancers.

As programmed cell death protein-1 (PD-1) inhibitor nivolumab and pembrolizumab showed efficacy in some patients, immunotherapy alone began to be used for treating SCLC.

Since then, phase 3 clinical trials of cytotoxic chemotherapy combined with immune-oncology were conducted to check for safety and efficacy.

The study involved 403 patients with extensive-stage SCLC, and the patients received atezolizumab plus chemotherapies etoposide and carboplatin.

Researchers confirmed that the median progression-free survival and overall survival in the atezolizumab combo group were 5.2 months and 12.3 months, respectively, higher than the placebo group's 4.3 months and 10.3 months.

Based on the study results, the U.S. Food and Drug Administration approved the combination therapy of atezolizumab, etoposide, and carboplatin as first-line treatments for SCLC.

The research team also conducted a retrospective study on the efficacy and safety of the combined therapy of atezolizumab, etoposide, and carboplatin in Korean patients.

The 11.6 month-long follow-ups of 68 patients with extensive-stage SCLC at YCC showed a median progression-free survival of 4.6 months and a median overall survival of 12.0 months, similar to the previous phase 3 clinical trial.

“In the recent study, we have reaffirmed the efficacy and safety of combined administration of cytotoxic chemotherapy and immune-oncology for patients with extensive-stage SCLC in real-world data,” Professor Hong said. “We expect the study results to help in developing therapies for SCLC as we have also identified factors that could lead to poor prognosis for the patients.”

The study results were published in the Cancer Immunology, Immunotherapy.