ASTRO 2021: Can PD-L1 Expression Predict Outcomes in Unresectable Stage 3 NSCLC?
Posted: Tuesday, November 2, 2021
Research presented at the 2021 American Society for Radiation Oncology (ASTRO) Annual Meeting (Abstract 20) suggested that high PD-L1 expression on the cancer-associated macrophage-like (CAML) cells of some patients with unresectable stage III non–small cell lung cancer may serve as a predictive biomarker for clinical outcomes. Steven H. Lin, MD, PhD, of MD Anderson Cancer Center in Houston, and colleagues found that the predictive benefit seemed to be seen in patients who had been treated with immunotherapy, not in those treated with chemoradiation alone.
The study included two sets of patients, both of which had been treated with immunotherapy. One set (n = 34) had received chemoradiation plus atezolizumab in a single-arm phase II trial, whereas the other (n = 46) had received chemoradiation plus consolidation with the monoclonal antibody durvalumab. A total of 55 patients who had undergone chemoradiation monotherapy were also evaluated.
Across all samples, CAMLs were present in 92%. The average number of CAMLs identified was 5.2 CAMLs/15 mL. A high CAML PD-L1 presence did not appear to be associated with progression-free survival among any of the three patient groups. However, high CAML PD-L1 expression seemed to be linked to superior progression-free survival for patients given atezolizumab and durvalumab following chemoradiation.
According to the investigators, high CAML PD-L1 expression was closely associated with improved overall survival for the atezolizumab and durvalumab groups. Across both combination treatment groups, 57% of patients had demonstrated high PD-L1 expression before and after chemoradiation or experienced an increase in PD-L1 expression versus baseline. Patients who had high PD-L1 expression after chemoradiation were more likely to experience improved outcomes than patients who had low PD-L1 expression.
Disclosure: For full disclosures of the study authors, visit astro.org.
