Mapping the treatment journey following antibody-drug conjugate (ADC) initiation: Sequencing patterns and real world overall survival (rwOS) in non-breast solid tumors in a US community setting.

Abstract

e23362 Background: With the clinical application of ADCs in solid tumors, there is a need to understand treatment sequencing of ADCs and outcomes in the real-world (rw) setting. This retrospective observational study evaluates the characteristics, treatment patterns, and OS in patients (pts) with non-breast solid tumors who received ADC treatment in a rw setting. Methods: This study included pts (≥18 y) who initiated a 1st ADC (index ADC) for bladder, ovarian, NSCLC, gastric, or cervical cancers from Jan 2020 to Aug 2024 based on deidentified pt-level data in a US community setting from the iKnowMed EHR database (cut off: Feb 28, 2025). Primary index date was defined as initiation of index ADC treatment. For cohorts with ≥30 pts, rwOS was assessed based on tumor type and the setting in which the index ADC was received. Results: Among 1592 pts included in this study, 1045 had bladder cancer, 243 had ovarian cancer, 119 had NSCLC, 93 had gastric cancer, and 92 had cervical cancer. Across tumor types, median age ranged 51–73 y. At initial diagnosis, 52.3%, 37.9%, 75.6%, 67.7%, and 45.7%, respectively, had stage IV disease. Median follow-up was 7.6, 8.0, 8.1, 5.1, and 6.7 mo, respectively. Index ADC distribution by tumor type and treatment setting is shown in Table. Among pts with bladder cancer who received a 2nd ADC after index ADC (n=139 [13.3%]), 20 received enfortumab vedotin (EV) + pembrolizumab (pembro) as the index ADC, of whom 17 (85.0%) received sacituzumab govitecan (SG) as the 2nd ADC; 109 pts received EV monotherapy or EV + other (non-pembro) as the index ADC, of whom 106 (97.2%) received SG as the 2nd ADC. Among pts who received ADC in metastatic settings, median rwOS for metastatic regimen 1 (R1) and metastatic regimen 2 or beyond (R2+) was 17.4 and 12.6 mo for bladder cancer, 19.4 and 16.3 mo for ovarian cancer, 16.7 and 14.4 mo for NSCLC, and 10.8 and 7.8 for gastric cancer, respectively; median rwOS for R2+ was 12.1 mo for cervical cancer. Conclusions: Across 5 solid tumor types, rw ADC sequencing patterns varied. Median rwOS remains low, although it was longer in pts who received ADC as R1 vs later lines (R2+). These rw data provide a necessary bridge from clinical trial results to clinical practice by informing optimal sequencing and timing of ADCs. Distribution of index ADC treatments received by setting and tumor type. ADC Treatment Bladder (n = 1045) NSCLC (n = 119) Gastric (n = 93) Ovarian (n = 243) Cervical (n = 92) EV + pembro EV mono or EV + other (non-pembro) T-DXd SG T-DM1 T-DXd T-DXd Mirvetuximab soravtansine T-DXd Tisotumab vedotin T-DXd Neoadjuvant or adjuvant n 81 25 - 2 1 - 6 18 1 6 - % 75.0 23.1 - 1.9 100 - 100 94.7 5.3 100 - R1 n 355 163 1 12 18 65 39 48 3 23 1 % 66.8 30.7 0.2 2.3 21.7 78.3 100.0 94.1 5.9 95.8 4.2 R2+ n 53 335 - 18 8 27 48 161 12 58 4 % 13.1 82.5 - 4.4 22.9 77.1 100.0 93.1 6.9 93.5 6.5 T-DM1, trastuzumab emtansine; T-DXd, trastuzumab deruxtecan.