Posted: Friday, November 11, 2022
During the 2022 American Society for Radiation Oncology (ASTRO) Annual Meeting (Abstract 146), Percy Lee, MD, of The University of Texas MD Anderson Cancer Center, Houston, and colleagues presented the efficacy and safety results of a phase II study of stereotactic ablative radiotherapy with the immune checkpoint inhibitor durvalumab in early-stage, inoperable non–small cell lung cancer (NSCLC). Ultimately, the results of this study concluded that this therapeutic combination resulted in “excellent disease-specific outcomes.”
“Safety was promising, but this study underscored the importance of excluding patients with any fibrotic lung disease for safety and optimal interpretation of adverse event data,” mentioned the study authors. “[These] results support ongoing phase III trials determining the benefit of stereotactic ablative radiotherapy with durvalumab in these patients.”
The investigators focused on 18 patients with newly diagnosed, biopsy-proven clinical stage I or IIa NSCLC that was medically inoperable. Patients were administered one cycle of durvalumab followed by stereotactic ablative radiotherapy at 54 Gy in 3 fractions, 50 Gy in 4 fractions, or 65 Gy in 10 fractions, and four subsequent cycles of durvalumab.
The median follow-up was 2.6 years. The majority of patients (78%) received all five cycles of durvalumab, two received one cycle, and one received three cycles. The 1- and 2-year local control rates were 100% and 93%, respectively, and progression-free survival rates were 94.4% and 83.3%. The 1- and 2-year overall survival rates were 94.4% and 88.9%, respectively. Additionally, the 2-year cumulative incidence for lung cancer–specific survival was 94.4%.
When stratified by median gross tumor volume, the 2-year overall survival rate was higher among patients with a tumor volume of less than 7.9 mL than one of more than 7.9 mL (P = .07). Late and acute grade 3 or higher treatment-related toxicities were of cardiac, pulmonary, and gastrointestinal nature. Grade 4 pneumonitis affected one patient. Additionally, one patient died of treatment-related respiratory failure because of baseline fibrotic lung disease.
Disclosure: To see Dr. Lee’s disclosure information, visit plan.core-apps.com.