Abstract Rationale Lung cancer remains the leading cause of cancer-related mortality. The introduction of immune checkpoint inhibitors (ICIs) improved outcomes. However, ICIs carry a risk of ICI-pneumonitis, which can impact outcomes and treatment. This study looked at the rates of pneumonitis between different ICI therapies in patients with and without thoracic radiation. Methods We retrospectively reviewed NSCLC and SCLC patients aged 21-85 years at The University of Connecticut who underwent PFTs within three years prior to ICI therapy. We excluded patients older than 85 years old due to anticipated life expectancy. ICI therapy included PD-L1 (Atezolizumab, Durvalumab) and PD-1 (Pembrolizumab, Nivolumab) therapies. The primary outcome was the development of ICI-pneumonitis defined by the American College of Chest Physicians criteria. We looked at the rates of pneumonitis by ICI therapy using Pembrolizumab as the referent. We also examined the difference in the occurrence of pneumonitis in patients treated with ICI therapy alone versus ICI therapy and radiation. Results Of 1,253 patients treated with ICIs, 153 had pre-treatment PFT data. 91 were treated with Pembrolizumab, 28 with Durvalumab, 16 with Nivolumab, and 16 with Atezolizumab. Of those 153 patients, 41 (26.8%) developed pneumonitis. Of those, 21 patients were treated with Pembrolizumab, 12 with Durvalumab, 6 with Nivolumab, and 2 with Atezolizumab. Patients treated with Durvalumab were significantly more likely to develop pneumonitis compared to those treated with Pembrolizumab (HR 1.88, 95% CI 1.05-3.28) (p = 0.05). Patients treated with Nivolumab (HR 1.63, 95% CI 0.779-3.390) (p = 0.23) and Atezolizumab (HR 0.542, 95% CI 0.140-2.089) (p = 0.51) were not significantly more likely to develop pneumonitis. Among the 91 patients treated with Pembrolizumab, 66 were also treated with radiation therapy and 17 developed pneumonitis (HR 1.61, 95% CI 0.60-4.32) (p = 0.41). Of the 28 patients treated with Durvalumab, 23 were treated with radiation therapy and 10 developed pneumonitis (HR 1.09, 95% CI 0.34-3.50) (p = 1.00). Of the 16 patients treated with Nivolumab, 14 were treated with radiation and 5 developed pneumonitis (HR 0.71, 95% CI 0.15-3.38) (p = 1.00). Of the 16 patients treated with Atezolizumab, 9 were also treated with radiation therapy and 2 of these patients developed pneumonitis (HR 4.00, 95% CI 0.22-72.02) (p = 0.48). Conclusions In this single-center cohort study, Durvalumab was associated with significantly higher risk of ICI pneumonitis. These findings underscore the importance of pre-treatment evaluation. This abstract is funded by: None
Pasichnik et al. (Fri,) studied this question.