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 PFS (progression free survival) and OS (overall survival). Unfortunately, Durvalumab is currently not reimbursed for this indication in Lebanon so far. We have used Atezolizumab on a series of patients to the similar mechanism of action. We report in this paper the incidence of pneumonitis using this approach. Methods: We selected from our lung cancer registry, a group of patients diagnosed with stage III NSCLC, who received Atezolizumab (Tecentriq) as consolidation therapy following concurrent chemoradiation therapy. We specifically look at the incidence and severity of pneumonitis based on Common Toxicity Criteria and Adverse Events (CTCAE). Finally, we analyzed patient and tumor characteristics looking for predictive markers for pneumonitis. Result: Of the 14 patients who met our selection criteria, 8 developed pneumonitis and 6 did not. Age, gender and smoking status did not affect the probability of having pneumonitis, with p-values of 0.98,1 and 0.86 respectively. The impact of having PDL-1 status on pneumonitis could not be assessed due to our small sample size. The mean onset of pneumonitis after completion of chemoradiotherapy is 3.62 and after starting Atezolizumab is 2.45 months. Conclusion: The administration of Atezolizumab carries a significant risk of developing pneumonitis following chemoradiation therapy for NSCLC. The presence of certain factors and tumor characteristics might affect the chances of having pneumonitis. However due to our small sample size, definitive conclusions could not be drawn.