Rate and risk factors of recurrent immune checkpoint inhibitor-related pneumonitis in patients with lung cancer.

Abstract

Immune checkpoint inhibitors (ICIs) have become standard treatments for lung cancer patients. Immune checkpoint inhibitor-related pneumonitis (CIP) was the leading cause of death among ICIs-related adverse events (irAEs). Recurrent episodes of CIP without rechallenge of ICIs were reported in several cases and maybe a unique feature of CIP. Knowledge gaps remain regarding the rate and risk factors associated to CIP's recurrence. Data from 1,102 lung cancer patients receiving ICIs treatment between January 2016 and January 2021 were retrospectively collected and analyzed. CIP was diagnosed according to typical clinical features and/or new typical imaging changes. Recurrence of CIP (CIP-R) was defined as recurrent CIP after initial CIP improved after proper treatment. Logistic regression was used to assess risk factors associated with CIP recurrence. Eighty out of 1,102 (7.26%) patients were diagnosed with CIP. Twenty of those 78 (25.64%) patients suffered CIP-R, 2 patients died and were therefore excluded from the denominator. The median onset of initial pneumonitis for patients without and with recurrence was 3.49 months [interquartile range (IQR), 0.26-31.93 months] and 2.78 months (IQR, 1.22-20.93 months), respectively (P=0.48). The median interval duration between initial CIP and CIP-R was 1.54 months (IQR, 0.98-16.70 months). Recurrence of CIP was more common in males (P=0.03), squamous histology (P=0.016), and in patients who received chest radiotherapy (P=0.049). The duration of prednisolone equivalent dose ≥15 mg/day in CIP-R was significantly shorter, at 3.71 weeks (2.86-6.57 weeks) compared with 6.36 weeks in those without recurrence (IQR, 3.12-9.86 weeks) (P=0.001). Non-squamous histology [odds ratio (OR), 0.182; 95% confidence interval (CI): 0.038-0.860; P=0.031] and prolonged administration of prednisolone equivalent dose ≥15 mg/day for more than 4 weeks (OR, 0.082; 95% CI: 0.02-0.342; P=0.001) were independently associated with a decreased odds of CIP-R development. CIP-R in a real-world lung cancer cohort is not uncommon, both in patients with and without rechallenge of ICIs. A duration of prednisolone equivalent dose ≥15 mg/day of at least 4 weeks during the tapering process of corticosteroids were recommend in patients with CIP.