Myung-Ju Ahn, MD

Formal discussant Myung-Ju Ahn, MD, of Samsung Medical Center Sungkyunkwan University, Seoul, South Korea, said that the CASPIAN results were similar to those of IMpower133, which found that the addition of the immune checkpoint inhibitor atezolizumab to etoposide/carboplatin significantly improved survival in the same setting. Atezolizumab is now approved for the indication by the U.S Food and Drug Administration.

“Durvalumab plus etoposide and platinum-based chemotherapy should now be considered a standard of care in extensive-stage SCLC, with both CASPIAN and IMpower133 confirming the role of PD-1/PD-L1 ­[programmed cell death protein 1/programmed cell death ligand 1] immunotherapy in the first-line setting,” Dr. Ahn said.

However, she added, the 3-month improvement in survival is “still modest,” suggesting the need for biomarkers that will improve patient selection. Both PD-L1 and tumor mutational burden have not fulfilled that promise.

Dr. Ahn commented that the median progression-free survival was similar in both arms but favored durvalumab across the study period, especially at the 12-month time point. She suggested that this may be due to a “delayed” effect of continued maintenance therapy with durvalumab.

‘A Tremendous Advance’

Roy S. Herbst, MD, PhD

Roy S. Herbst, MD, PhD, who was not involved in the CASPIAN trial, hailed these results as an advance. Dr. Herbst is Chief of Medical Oncology and Associate Director for Translational Science at the Yale Cancer Center, New Haven, Connecticut.

“The fact that immunotherapy works for small cell lung cancer is a tremendous advance. CASPIAN is clearly a positive study. The data look quite similar to those of IMpower133 with atezolizumab. CASPIAN reaffirms that result, but unfortunately it does not represent a step up for improved outcome. We will need better biomarkers to select patients and/or to alternate combinations of drugs to use in this setting to improve outcomes,” Dr. Herbst commented. 

DISCLOSURE: Dr. Ahn has disclosed relationships with AstraZeneca, Takeda, Merck, Bristol-Myers Squibb, Boehringer Ingelheim, Roche, Alpha Pharmaceuticals, and Ono Pharmaceuticals. Dr. Herbst is a consultant for AbbVie Pharmaceuticals, Armo Biosciences, AstraZeneca, Biodesix, Bristol-Myers Squibb, Eli Lilly, EMD Serrano, Genentech/Roche, Genmab, Halozyme, Heat Biologics, Infinity Pharmaceuticals, Loxo Oncology, Merck, Nektar, Neon Therapeutics, NextCure, Novartis, Pfizer, Sanofi, Seattle Genetics, Shire PLC, Spectrum Pharmaceuticals, Symphogen, Tesaro, and Tocagen; has received research support from AstraZeneca, Eli Lilly, and Merck; and is a member of the Board of Directors (nonexecutive/independent) for Junshi Biosciences.