Treatment patterns in extensive-stage small cell lung cancer: A retrospective real-world data study.

288 Background: Etoposide plus platinum-based chemotherapy (EP) was the first-line (1L) extensive stage small cell lung cancer (ES-SCLC) standard of care for many years. 1L treatment with immunotherapy (durvalumab or atezolizumab) combined with carboplatin (durvalumab, atezolizumab) or cisplatin (durvalumab) chemotherapy (CT) is now being accepted as the new standard of care in this population. This study used real-world data to describe treatment patterns of ES-SCLC patients in the United States following the introduction of immunotherapy (IO). Methods: Data for patients ≥18 years of age with an index ES-SCLC treatment from 17 October 2018 to 30 November 2019 (or no 1L treatment within 60 days of an index diagnosis during this period) were drawn from the Flatiron electronic medical records database. Proportions of patients receiving specific 1L and second-line (2L) treatments were calculated. Times from (a) index diagnosis to 1L start, (b) 1L start to 1L end (c) 1L start to 2L start, and (d) 2L start to 2L end were calculated with 95% confidence intervals (for sample sizes ≥ 30) for the CT and IO+CT treatment categories. Results: 568 patients met the inclusion/exclusion criteria: 77 (14%) were untreated 60 days after their index diagnosis; 491 received 18 different 1L treatments (1L CT: 195; 1L IO+CT: 286, other 1L therapy: 10); and 119 received 2L treatment following 1L CT or IO+CT. The table shows the most frequently occurring 1L and 2L treatments. The mean number of days [#patients, 95% confidence interval] for 1L CT and 1L IO+CT respectively were (a) index diagnosis to 1L start: 22 [194 (1 patient began 1L therapy prior to their index diagnosis); 20–26], 22 [286, 20–24]; (b) 1L start to 1L end: 58 [174, 52–66], 91 [125, 79–103]; (c) 1L start to 2L start: 115 [83, 99–133], 186 [36, 168–205]; (d) 2L start to 2L end: 55 [54, 42–69] and 36 [N = 21]. Conclusions: Most ES-SCLC patients started therapy within a month of diagnosis. Over 50% received 1L IO+CT, reflecting its rapid uptake in the US. Almost 14% patients did not receive 1L treatment and only ~25% of 1L CT and 1L IO+CT patients received 2L therapy within the study period; reasons for this warrant further investigation. [Table: see text]