95P Understanding the real-world (RW) impact of time between treatment regimens on clinical outcomes in patients with metastatic NSCLC previously treated with immunotherapy (IO) in the US community oncology setting

IO has transformed the treatment of first-line (1L) metastatic NSCLC (mNSCLC) in patients without actionable biomarkers, though patients with intolerance and disease progression require subsequent treatment. With this evolution, there is a newfound need to understand the optimal sequencing and timing of regimens. This study investigated RW treatment patterns and clinical outcomes in this setting. This retrospective observational study included adult patients with mNSCLC previously treated with 1L IO who initiated subsequent treatment between 2015-2020 in The US Oncology Network (followed through 31 March 2022). Patient characteristics and treatment patterns were assessed descriptively using structured electronic health record data. Kaplan-Meier analyses of RW overall survival (rwOS), time to treatment discontinuation (rwTTD) and time to next treatment (rwTTNT) were conducted by evaluating post-IO treatment-free interval (TFI), defined as the duration between last IO administration date and post-IO regimen start. Overall, 1,116 patients were identified (median follow-up 7.2 months). Most were age ≥65 years (62%), White (73%), male (52%) and had a history of tobacco use (82%). Subsequent treatment was initiated ≤30 days from last IO in 45% of patients, and 17% had post-IO TFI >90 days. There were no statistically significant differences in age, sex, race, tobacco use, ECOG or histology by post-IO TFI category. Post-IO regimens and clinical outcomes by post-IO TFI are summarized below.Table: 95PPost-IO TFI ≤30 daysPost-IO TFI 31-60 daysPost-IO TFI 61-90 daysPost-IO TFI >90 daysLogrank P-valueN49934579193-Post-IO regimens, n (%)-IO (resumed or switched)136 (27)66 (19)13 (16)119 (62)Docetaxel ± ramucirumab132 (26)126 (37)27 (34)22 (11)Platinum chemotherapy + pemetrexed or paclitaxel91 (18)71 (21)20 (25)16 (8)Gemcitabine45 (9)29 (8)7 (9)6 (3)Other non-IO*95 (19)53 (15)12 (15)30 (16)Outcomes, median (95% CI), monthsrwOS10.8 (9.2,12.2)7.5 (6.8,9.1)9.2 (5.8,17.5)16.0 (12.7,20.8)<0.0001rwTTD3.7 (3.3,4.2)2.9 (2.3,3.5)2.8 (2.2,3.6)3.2 (2.4,4.0)0.0025rwTTNT6.1 (5.7,6.7)4.9 (4.5,5.4)5.7 (4.5,7.2)7.8 (6.1,9.7)<0.0001*Other = regimens with <5 patients in ≥1 subgroup Open table in a new tab *Other = regimens with <5 patients in ≥1 subgroup This RW study highlights the variation in treatments and outcomes by TFI among patients with mNSCLC previously treated with IO. TFI ≤30 days may represent avoided delays in treatment, whereas TFI >90 days may include patients with long-term response. Further research is needed to optimize treatment strategies in this setting.