Real-world safety and efficacy of concurrent immunotherapy and thoracic chemoradiotherapy: A multi-institutional analysis.

e23262 Background: Despite the success of Immune checkpoint inhibitors (ICIs) as consolidation following concurrent chemoradiotherapy (CCRT), 22% to 30% of patients still cannot be treated with durvalumab due to progression or adverse events (AEs) during or after CCRT. Concurrent ICIs with CCRT would offer the opportunity to receive ICIs and may provide treatment benefit to a greater proportion of patients. In this study, we performed a multicenter investigation to evaluate the safety and efficacy of ICIs and chemotherapy with concurrent thoracic radiotherapy. Methods: All patients from three institutions who underwent ICIs and concurrent thoracic radiotherapy were included. The rate of 12-month progression-free survival (PFS) was estimated using the Kaplan-Meier method and evaluated with 95% CIs calculated using the Greenwood formula. Therapy-related pneumonitis (TRP) and esophagitis (TRE) were defined per CTCAE v5.0. Statistics utilized logistic regression modeling and receiver operating characteristic (ROC) analysis. Results: 69 patients (median range age, 62 52-76; 61 88.4% male; median follow-up 30.4 months) were collected, including 18 (26.1 %) cases of non-small cell lung cancer (NSCLC), 26 (37.7 %) cases of small cell lung cancer (SCLC), and 25 (36.2 %) cases of esophageal cancer (EC). The 12-month PFS rates in NSCLC, SCLC and EC were 72.2%, 69.2% and 72.0%, respectively. The median PFS in NSCLC and SCLC was 24.3 and 13.1 months, and not reached (mean 29 months) for EC. The incidences of all-grade TRP and TRE were 60.7% and 57.7%, respectively. Grades 1-5 TRP occurred in 15.9%, 30.4%, 8.6%, 1.4%, and 0, respectively. Grades 1-5 TRE occurred in 20.2%, 28.9%, 8.6%, 0, and 0, respectively. On multivariable analysis, age and MLD significantly predicted for any-grade and grade ≥2 TRP. Only age significantly predicted for grade ≥3 TRP. ROC analysis was able to pictorially model RP risk probabilities for a variety of MLD and age thresholds. Conclusions: This real-world study can be helpful for understanding the true efficacy and toxicity of ICIs and chemotherapy with concurrent thoracic radiotherapy given the lack of robust clinical data. Close monitoring should be recommended in this patient population during RT and follow-up.