Investigating risk factors and treatment options for severe, partially steroid responsive, and steroid-refractory checkpoint inhibitor pneumonitis.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have revolutionized cancer care with incredible reductions in mortality. One of the most devastating complications of treatment is ICI-related pneumonitis (ICI-p). Despite this, little is known regarding risk factors for severe pneumonitis and treatment effectiveness of various therapeutic options for steroid-refractory disease. To address this, we conducted a retrospective study on patients with cancer who developed ICI-p. METHODS: We examined consecutive patients who received ICIs and developed ICI-p. Risk factors of interest for severe disease and steroid-refractory ICI-p, including pre-treatment pulmonary function tests (PFTs) and chest imaging, were compared between patients with severe (grades 3-5) and mild (grades 1-2) pneumonitis. The clinical and treatment courses for patients with steroid-refractory ICI-p were recorded. RESULTS: A total of 132 patients developed ICI-p, with 60 patients having mild and 72 with severe disease. We found that lower forced vital capacity percent predicted (66.24 vs 85.05, P = .05), lower total lung capacity percent predicted (85.23 vs 99.71, P = .13), and specific radiographic patterns on pre-treatment chest imaging were predictors of severe disease. Initial corticosteroid dose of less than 1 milligram per kilogram prednisone equivalent (P = .14) was correlated with partially steroid-responsive or steroid-refractory ICI-p. Ten patients had steroid refractory ICI-p, and those who received IVIG alone as the immune suppressant beyond corticosteroids had improved survival (P = 05). CONCLUSIONS: We are the first to identify pre-treatment PFTs and chest imaging abnormalities as risk factors for severe ICI-p. We also found that lower corticosteroid doses were associated with partially steroid-responsive and steroid-refractory ICI-p. Larger, prospective studies are needed to validate our results.

Sarcoid-like reactions to immune checkpoint inhibitors: Incidence, treatment course, and impact on cancer progression and survival.

INTRODUCTION: Sarcoid-like reactions (SLRs) to immune checkpoint inhibitors (ICIs) are a rare but increasingly recognized immune-related adverse event of which the clinical significance is unclear. METHODS: We conducted a retrospective cohort study at a tertiary academic center of consecutive patients who received at least one dose of ICI from 2013 to 2020. Patient characteristics, risk factors, and outcomes were compared between patients with and without SLR following ICI treatment. RESULTS: A total of 2963 cancer patients received at least 1 dose of ICI between 2013 and 2020, and 7 patients (0.24 %) developed SLR. There were no significant demographic differences between patients with and without SLR following ICI. SLRs occurred in 5 of 451 (1.07 %) melanoma patients and 2 of 840 (0.24 %) non-small cell lung cancer patients. Two of the 7 patients had multi-organ SLR, and both were symptomatic requiring systemic corticosteroids and permanent ICI discontinuation, while single organ SLR patients did not require immune suppression. Development of SLR did not appear to have negative impact on cancer progression or overall survival; in fact, a trend towards improved progression-free and overall survival was observed (median time: 1363 days vs 127 days, p = 0.091; 1387 days vs 428.5 days, p = 0.19, respectively). CONCLUSIONS: SLRs are a known but understudied complication associated with ICI therapy. Multisystem SLR patients were more symptomatic and required ICI discontinuation and immune suppression. Larger studies are needed to fully evaluate the impact of SLR on cancer outcomes.