Everolimus-Induced Pneumonitis in Patients with Neuroendocrine Neoplasms: Real-World Study on Risk Factors and Outcomes

Background Everolimus-induced pneumonitis (EiP) has been poorly studied in patients with neuroendocrine neoplasms (NEN) outside clinical trials. The aim of this study was to evaluate the incidence, risk factors, and outcomes of EiP in patients with NENs using real-world data. Methods Retrospective study of everolimus-treated patients with advanced NENs. Imaging reports were systematically reviewed for the presence of pneumonitis. Clinical features and treatment profiles for EiP were summarized. Overall survival (OS) was calculated from the initiation of everolimus to the date of death or last follow-up using the Kaplan-Meier method. Results A total of 122 patients were included. Median age at start of everolimus was 62 (19-86) years, 62% (76/122) were male, and half were from pancreatic origin (62, 51%). Twenty-eight patients (23%) developed EiP: 82% grade (G)1 or G2, 14% G3 and 4% G4. The median time to EiP was 3.6 (0.8-51) months. Primary tumor site, concurrent lung disease, smoking history, and prior therapies were not associated with the onset of EiP. Patients who developed EiP had longer time on everolimus treatment (median 18 months vs 6 months; P = .0018) and OS (77 months vs 52 months; P = .093). Everolimus-induced pneumonitis was a predictor of improved OS by multivariable analysis (HR 0.39, 95% CI 0.19-0.82; P = .013). Conclusion Everolimus-induced pneumonitis in the real-world clinical setting is present in one quarter of patients with NENs receiving everolimus and often occurs early. While risk factors for EiP were not identified, patients with EiP had improved survival.