Historically, small cell lung cancer has been one of the deadliest malignancies, with an overall five-year relative survival rate of just 7%, according to the American Cancer Society. However, research breakthroughs are aiming to change that – and researchers at Inova Schar Cancer Institute are leading the way.
In June 2023, Nagla Abdel Karim, MD, thoracic medical oncologist, Director of Developmental Therapeutics at Inova Schar Cancer Institute, and Professor of Medicine at the University of Virginia School of Medicine presented the results of an exciting new research study at the American Society of Clinical Oncology’s 2023 annual meeting. The study’s title is SWOG S1929: Phase II randomized study of maintenance atezolizumab (A) versus atezolizumab + talazoparib (AT) in patients with SLFN11 positive extensive stage small cell lung cancer (ES-SCLC).
“This is a groundbreaking milestone in building future studies for small-cell lung cancer towards a personalized approach to therapy. Progression-free survival is of great clinical significance, especially in this aggressive disease,” Dr. Abdel Karim said.
The multicenter study, led by Dr. Abdel Karim, looked at patients whose small cell lung cancer was advanced (called extensive stage). Previous studies had established that people with a certain biomarker in their genetic code (called the Schlafen-11 gene, abbreviated SLFN11), responded better to certain drugs – called PARP inhibitors – than people who did not have the SLFN11 gene. In the SWOG S1929 study, Dr. Abdel Karim and her colleagues wanted to find out if adding a PARP inhibitor to the standard treatment for extensive stage small cell lung cancer would improve survival.
Within the S1929 study, potential trial participants, all of whom had extensive stage small cell lung cancer, were tested to find out if they had the SLFN11 gene (called being SLFN11 positive). Those who did – approximately 79 percent of the patients tested – were randomly assigned to one of two groups. The first group – called the control group – received the standard treatment for small cell lung cancer (front-line chemotherapy with atezolizumab followed by maintenance atezolizumab immunotherapy). The second group received the standard treatment (followed by maintenance atezolizumab immunotherapy), plus a PARP inhibitor (called talazoparib). Then, the research team tracked survival rates.
The results were dramatic. The trial group (those who received the addition of a PARP inhibitor) had significantly longer progression-free survival (meaning the period of time during which their cancers did not advance). The trial group had a medial progression-free survival rate of 4.2 months, versus only 2.8 months for the control group.
According to Dr. Karim, this study may signal a turning point for small cell lung cancer treatment. “There is hope for people with small cell lung cancer, not only to have novel treatments, but also to benefit from predictive biomarkers that can help determine which patients will respond best to which treatments,” she said.
The dedicated physician scientists at Inova Schar Cancer Institute continue to work on studies of national and international significance in oncology research. “While we don’t have all the answers yet for small cell lung cancer – it’s a difficult disease to treat – that does not prevent our doctors at Inova from pursuing clinical trials to improve treatments and quality of life for people with this disease, both now and in the future,” Dr. Karim said.
This clinical trial was conducted in partnership with the SWOG Cancer Research Network and was funded by the National Cancer Institute.