The updated results from the CASPIAN Phase III trial showed that AstraZeneca’s Imfinzi (durvalumab) in combination with a choice of chemotherapies, etoposide plus either carboplatin or cisplatin, demonstrated a sustained, clinically meaningful overall survival (OS) benefit at three years for adults with extensive-stage small cell lung cancer (ES-SCLC) treated in the 1st-line setting.

These data, which show the longest survival update ever reported for immunotherapy treatment in this setting, were presented during a mini-oral session on Sept 18, 2021, at the European Society of Medical Oncology (ESMO) Congress 2021.

The CASPIAN trial met the primary endpoint of OS in June 2019 reducing the risk of death by 27% (based on a hazard ratio [HR] of 0.73; 95% confidence interval 0.59-0.91; p=0.0047), which has formed the basis of regulatory approvals in many countries around the world. Updated results were previously presented during the ASCO20 Virtual Scientific Program in May 2020 with a median follow up of more than two years.

The latest results for Imfinzi plus chemotherapy showed sustained efficacy after a median follow up of more than three years for censored patients, with a 29% reduction in the risk of death versus chemotherapy alone (based on an HR of 0.71; 95% CI 0.60-0.86; nominal p=0.0003). Updated median OS was 12.9 months versus 10.5 for chemotherapy.

Luis Paz-Ares, MD, PhD, Chair, Medical Oncology Department, Hospital Universitario 12 de Octubre, Madrid, Spain and principal investigator in the CASPIAN Phase III trial said: “These results reinforce Imfinzi plus platinum chemotherapy as an important standard of care in this setting.”

Susan Galbraith, Executive Vice President, Oncology R&D, said: “This remarkable improvement in survival is an unprecedented achievement at three years for patients with extensive-stage small-cell lung cancer. We are deeply committed to helping improve survival rates in this disease with research into new treatment options to transform outcomes at various stages, not only with the CASPIAN trial but also with the ADRIATIC trial in limited-stage disease.”

Imfinzi plus chemotherapy continued to demonstrate a well-tolerated safety profile consistent with the known profiles of these medicines. Results showed 32.5% of patients experienced a serious adverse event (all causality) with Imfinzi plus chemotherapy versus 36.5% with chemotherapy alone.

Imfinzi in combination with etoposide and either carboplatin or cisplatin is approved in the 1st-line setting of ES-SCLC in more than 55 countries, including the US, Japan, China and across the EU.