Pneumonitis in Non-Small Cell Lung Cancer Patients Receiving Atezolizumab Post Chemo-Radiation

Objective: The use of Durvalumab following chemoradiotherapy in patients with stage III NSCLC considerably increased progression-free survival (PFS) and overall survival (OS). However, Durvalumab is currently not reimbursed for this indication in Lebanon. We used Atezolizumab in a series of patients due to its similar mechanism of action and report the incidence of pneumonitis using this approach. Methods: From our lung cancer registry, we selected patients with stage III NSCLC who received Atezolizumab (Tecentriq) as consolidation therapy following concurrent chemoradiation therapy. We assessed the incidence and severity of pneumonitis based on Common Toxicity Criteria and Adverse Events (CTCAE) and analyzed patient and tumor characteristics for potential predictors. Results: Among 14 eligible patients, 8 developed pneumonitis and 6 did not. Age, gender, and smoking status did not affect pneumonitis risk (p=0.98, 1, and 0.86, respectively). PD-L1 status impact could not be assessed due to small sample size. Mean onset of pneumonitis was 3.62 months after completion of chemoradiotherapy and 2.45 months after starting Atezolizumab. Conclusion: Atezolizumab administration carries a significant risk of pneumonitis following chemoradiation for NSCLC. Certain factors and tumor characteristics might influence risk, but definitive conclusions are limited by small sample size.