Successful accrual of a cluster randomized controlled trial (RCT) comparing an educationally enhanced genomic tumor board (EGTB) intervention to usual practice (S2108CD, NCT# 05455606).

1544 Background: Observational studies show genomic tumor boards (GTBs) can enhance clinician knowledge and application of genomic tumor test (GTT) results. An RCT is needed to evaluate the impact of GTBs on treatment and outcomes. Conducting such a trial requires physician engagement and recruitment of an unbiased study population over a short period of time due to rapid changes in cancer genomics. S2108CD prospectively evaluates the impact of an educationally enhanced GTB (EGTB) intervention through a cluster RCT design across rural and community oncology practices in the United States. Methods: Recruitment Centers (RCs) were selected from the NCI Community Oncology Research Program (NCORP) with a focus on rural and minority/underserved (RMU) sites and cluster randomized 1:1 to EGTB intervention (virtual GTB and physician educational materials) versus usual practice (UP). Oncologists and their patients with advanced solid tumors who had GTT ordered were enrolled. The primary aim is to compare the proportion of patients receiving evidence-based genome informed therapy by arm. Here, we describe accrual and baseline characteristics of the RCs and the enrolled physicians and patients. Results: Between 8/2022 and 11/2024, 18 RCs were randomized to UP versus EGTB intervention. A median of 5 clinics (range, 1-13) comprised each RC. Six RCs were classified as RMU in each arm (n = 12). Overall, 121 physicians registered to the study and they registered 1284 patients (median 47.5 patients/month), of which 983 (77%) were registered at RMU RCs. In the UP arm, 614 patients and 61 physicians registered, and in the EGTB arm, 670 patients and 60 physicians registered (demographics of registered patients in table; unknown race/ethnicity [3%] not shown), meeting accrual goal within target timeframe. The 3 most common patient neoplasms were lung, mediastinal and pleural (n = 352, 27.4%), gastrointestinal (n = 344, 26.8%), and breast (n = 152, 11.8%). Conclusions: Timely accrual to S2108CD demonstrates the feasibility of conducting a cluster RCT to evaluate an EGTB intervention. There was high participation of RMU sites with a study population reflecting cancer types relevant for GTT; however, there were fewer than anticipated non-White and Hispanic patients registered. Study endpoint data are currently maturing. The final analysis of S2108CD will be conducted and reported in 2026. Clinical trial information: NCT05455606 . Patient characteristic Overall (N=1284, %) UP (N=614, %) EGTB (N=670, %) Age, median (range) 67.7 (20.3, 96.7) 67.6 (20.3, 96.7) 67.7 (22.4, 94.2) Sex Female 646 (50) 325 (53) 321 (48) Race American Indian or Alaska Native 10 (1) 4 (1) 6 (1) Asian 56 (4) 51 (8) 5 (1) Black or African American 88 (7) 26 (4) 62 (9) Native Hawaiian or other Pacific Islander 23 (2) 23 (4) 0(0) White 1047 (82) 490 (80) 557 (83) Multiracial 25 (2) 8 (1) 17 (3) Ethnicity Hispanic 106 (8) 25 (4) 81 (12)