Influence of data review on community physicians’ treatment preferences in frontline esophageal cancer (EC).

501 Background: EC remains a global health challenge with a rising incidence and poor prognosis despite advancements in treatment modalities. Standard therapies include surgery, chemotherapy (CT), radiation therapy, and recently, targeted and immunotherapy. The PD-L1 inhibitors pembrolizumab (pembro) and nivolumab (nivo) received FDA approval for frontline treatment in EC in March and May 2021, respectively, based in part on the KEYNOTE-590 (KN590) and CheckMate 648 trials. In this study, we aimed to uncover rationale in physician preference for PD-L1 inhibitors in EC. Methods: US-based oncologists convened at two in-person meetings in April 2024 to discuss clinical and real-world data presented at the 2024 ASCO GI Cancers Symposium. Among data discussed included the KN590 5-year update. Survey questions were fielded at the meeting to capture participants’ impressions. Demographics were captured via an online survey ahead of the meeting. Responses from participants who manage EC and responded to all survey questions were aggregated. Results: 86 participants qualified; and, collectively, are 76% community physicians with 18 years average in clinical practice, see 18 patients median on clinic days, and spend 83% of their time in direct patient care on average. ECOG PS status (50%), tumor histology (52%), and location/stage (48%) were reported as critical factors in treatment decision-making; only 14% said PD-L1 status was a major factor. Participants were queried on a hypothetical patient case of esophageal squamous cell and adenocarcinoma before and after reviewing the KN590 data. Prior to reviewing KN590, physician preferences in the squamous cell 1L setting were split between nivo+CT and pembro+CT; following data review, pembro+CT was favored nearly 3:1. In the adenocarcinoma 1L setting, preference shifted from 60/40 nivo+CT to 60/40 pembro+CT, see Table. The cohort were most impressed with the overall survival (87%) and objective response rates (40%), and 55% would consider pembro+CT for both squamous cell and adenocarcinoma disease while 37% would consider it for PD-L1 CPS>10 squamous cell disease only. Conclusions: Our study showed PD-L1 status was not a major factor in clinical decisions. The shift in treatment preference toward pembro+CT for both patient cases following KN590 data review suggests an impact for data review to influence physician behavior. This highlights the importance of educational initiatives to disseminate clinical updates to providers. It is still to be determined the optimal platform and length for these initiatives, and to quantify their effectiveness. 65-year-old male patient with advanced EC;PD-L1 CPS ≥10;ECOG PS of 1 Squamous cell disease Adenocarcinoma Before After Before After Fluoropyrimidine (FP) + platinum (P)-based CT 1% 1% 1% 0% FP +P-based CT + nivo 55% 27% 60% 36% FP + P-based CT + pembro 43% 71% 38% 63% Nivo + ipilimumab 1% 1% 0% 1% None of the above 0% 0% 0% 0%