What Is The Benefit From Second- And Third-Line (2l And 3l) Therapy For Extensive Disease Small Cell Lung Cancer (Ed-Sclc)? A Prospective Study Of Patterns, Discontinuation, And Survival In Us Community Practices.

e20567 Background: Limited 2L therapy options and no established 3L standard of care make treating relapsed ED-SCLC challenging. This study explores current treatment and outcomes in patients receiving 2L and 3L therapy in community practice. Methods: CA209-118, a prospective observational study of adult lung cancer patients in 70 US community practices, enrolled ED-SCLC patients on or before initiating 2L therapy from April 2014 to September 2017; they were followed until death, end of follow-up, or study withdrawal. Study sites reported therapy start and end dates and reasons for discontinuation. Platinum-refractory (PT-ref) was defined as a gap of ≤90 days between the end of 1L and start of 2L; platinum sensitive (PT-sen) was a > 90-day gap. Results: 165 ED-SCLC patients were enrolled prior to initiating 2L. The most common 2L therapies were topotecan (TOP, n = 89), PT + etoposide or irinotecan (ETOP or IRI, n = 30), paclitaxel monotherapy (PAC, n = 12), or nivolumab (n = 9). Mean age was 65 years, 53% were male, 96% were white, 94% were current or former smokers, and 17% had ECOG scores ≥2. At database (DB) lock, 26 (16%) completed 2L, 26 (16%) were still receiving 2L therapy, 78 (47%) discontinued 2L due to progression or death, 18 (11%) due to adverse events, and 17 (10%) for other reasons. In 2L, median OS was 5.1 months (95% CI: 4.6, 6.3) overall, 4.4 months (95% CI: 3.7, 5.8) for PT-ref patients (n = 69) and 6.3 months (95% CI: 5.1,7.8) for PT-sen patients (n = 96). Median time to discontinuation or death was 1.9 months (95% CI: 1.6, 2.3). The 91 3L patients most commonly received PAC (n = 24), TOP (n = 18), and PT + ETOP or IRI (n = 10). At DB lock, 13 (14%) completed 3L, 11 (12%) were still receiving 3L therapy, 45 (49%) discontinued due to progression or death and 22 (24%) due to AEs or other reasons. In 3L, median OS was 5.8 months (95% CI: 4.3, 7.1) and time to discontinuation was 2.1 months (95% CI: 1.4, 2.8). Conclusions: Treatment patterns in community practice for 2L and 3L appear largely limited to historical agents. Median survival and duration of therapy were short, highlighting the need for more effective and tolerable treatments in ED-SCLC.