LAUSR

Background: Pneumonitis (Pn) is a potentially life-threatening adverse event of some anticancer drugs. We compared treatment associated pneumonitis (TAP) related to immune checkpoint inhibitors (ICI) or chemotherapies (chemo) in advanced non-small cell lung cancer (aNSCLC) patients (pts) with and without (+/-) past medical history (PMH) of Pn, using data from clinical trials (CT) and real world data (RWD). Methods: Pts with PMH Pn in 8 aNSCLC CT comparing ICI to chemo, were identified using terms pneumonitis, acute interstitial pneumonitis, pneumonitis chemical, and interstitial lung disease. aNSCLC pts treated with ICI (+/- chemo) or chemo [without concurrent radiation therapy (RT)] were identified using RWD from a community health system; Pn was defined using terms in ICD-9 and ICD-10 including pneumonitis or associated concepts in the Unified Medical Language System. RWD pts were selected using core eligibility criteria from CT. In CT and RWD, Pn incidence proportion was calculated for 4 subgroups: pts (+/-) PMH of Pn and treated with ICI vs chemo. Pn diagnosis type, including RT Pn, was assessed. Results: In CT and RWD, a higher incidence of TAP was observed among aNSCLC pts with PMH of Pn compared to those without PMH of Pn, among ICI and chemo groups (Table 1). In CT pts without PMH of Pn, ICI associated Pn was more common than chemo associated Pn. Similar rates of TAP were observed in the CT and RWD. In RWD, Pn at any time was strongly associated with RT in ICI and chemo groups, with 73% of all diagnoses of Pn due to RT. Conclusion: PMH of Pn in pts with aNSCLC is associated with a greater risk of TAP for ICI and chemo groups, in CT and RWD. RWD data suggests RT to be a frequent cause of Pn. Only in CT data, and only for pts without PMH Pn, was there a demonstrated difference in TAP incidence between ICI and chemo groups. Additional research (e.g. inclusion of pts treated with tyrosine kinase inhibitors) is warranted to optimize treatment for cancer pts with PMH of Pn. Citation Format: Qi Liu, Chenan Zhang, Yutao Gong, Hao Zhu, Elaine Chang, Cheryl Cho-Phan, Jonathan Hirsch, Michael A. Thompson, Gideon Blumenthal, Shiew Mei Huang, Thomas D. Brown. Pneumonitis incidence in patients with non-small cell lung cancer treated with immunotherapy or chemotherapy in clinical trials and real-world data [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT086.