Tumor Mutation Burden Shows Promise in Small Cell Lung Cancer
From The ASCO Post:
Patients with small cell lung cancer (SCLC) and a high tumor mutation burden had a near doubling in response rate and 1-year overall survival when ipilimumab was combined with nivolumab, vs nivolumab alone, new findings from CheckMate 032 have shown. Regardless of the treatment arm, a high tumor mutation burden predicted better outcomes, as compared with a medium or low tumor mutation burden, Naiyer -Rizvi, MD, of Columbia University Medical Center, New York, reported at the 2017 International Association for the Study of Lung Cancer (IASLC) 18th World Conference on Lung Cancer in Yokohama, Japan.
In contrast to non–small cell lung cancer (NSCLC), programmed cell death ligand 1 (PD‑L1) tumor expression has not been a useful biomarker for SCLC, with most SCLC tumors being PD-L1–negative. Emerging data in NSCLC have suggested tumor mutation burden may be an important parameter of treatment response; this was further explored in SCLC.
“The results from CheckMate 032 provide clear evidence supporting the power of tumor mutation burden as a biomarker, not only for nivolumab response, but even more so for the combination of nivolumab and ipilimumab,” Dr. Rizvi said. “This may begin to impact prescribing practice in SCLC, where a tumor mutation burden biomarker can be used to select patients for combination immunotherapy with nivolumab and ipilimumab.”
Tumor Mutation Burden in SCLC
- In an exploratory analysis of CheckMate 032, tumor mutation burden was evaluated as a biomarker of response to nivolumab and nivolumab plus ipilimumab.
- In the study, 211 patients were divided into low, medium, and high tumor mutation burden tertiles.
- Patients in the high tumor mutation burden tertile had improved response rates, 1-year progression-free survival, and overall survival.