Results from the IMpower133 and CASPIAN trials gave the small-cell lung cancer (SCLC) community something to cheer about: Both studies showed benefit with add-on PD-L1 blockade — atezolizumab (Tecentriq) and durvalumab (Imfinzi), respectively — and both of those agents are now part of front-line SCLC care.
But initial excitement aside, the reality is that the incorporation of immunotherapy into the treatment paradigm has brought only moderate benefit to patients with SCLC, and more effective therapies are urgently needed, especially with “recently discovered four subtypes of SCLC, each with its unique therapeutic vulnerability,” said Lauren Byers, MD, of the University of Texas MD Anderson Cancer Center in Houston, and colleagues.
Writing in the ASCO Educational Book, Byers’ group offered an overview of SCLC care, including current treatment standards and promising emerging therapies.
In a presentation at the 2021 ASCO virtual meeting, Byers discussed some of those same points, and answered the question: “Molecular Subtypes in Small Cell Lung Cancer: Do They Impact Therapy?”
What is the current state of SCLC treatment?
Byers: Although SCLC is usually very sensitive to chemotherapy and to radiation initially, it often relapses within a few months of starting initial front-line therapy. And currently, there are no approved targeted therapies or biomarkers to guide treatment … We do have a new standard of care in the front-line setting for extensive-stage SCLC patients … and that is the addition of immune checkpoint blockade together with platinum etoposide chemotherapy.
What are some important details from the IMpower133 and CASPIAN trials?
Byers: In the IMpower133 trial, atezolizumab was added to platinum etoposide, and the CASPIAN trial added durvalumab. Both of these randomized phase III trials led to FDA approval based on about a 2-month improvement in overall survival with the addition of the immune checkpoint blockade.