OBJECTIVES/GOALS: The FDA allows physicians to request clinical use of investigational drugs, biologics, and devices for patients with no satisfactory treatment options through a pathway called Expanded Access (EA). TEAMSS (Transforming Expanded Access to Maximize Support and Study) sought to examine single-patient cases to better characterize these patients. METHODS/STUDY POPULATION: We prospectively collected data on requests for single-patient EA at any one of the four collaborating TEAMSS institutions (Duke University, University of Rochester, University of Michigan, and University of Texas Southwestern) between September 1, 2021 and February 28, 2023. Regulatory and health records were reviewed for past cases that occurred between June 1, 2018 and August 31, 2021. Descriptive statistics were performed on data from the submission process, the patient demographics, the indication for treatment, and patient health status over time. RESULTS/ANTICIPATED RESULTS: The patient population was representative with respect to the largest racial groups (69.3% White / 13.0% Black or African American) and legal sex (51.3% male / 48.7% female). All ages were represented, with overrepresentation of those 60-70 years old (16.8%) and under 10 (14.8%). Patients were most often treated for infectious diseases (44.2%) or oncologic conditions (39.0%). Those who received more than one dose stayed on treatment for 76 days (median) and up to 1427 days (maximum). At the end of study, 53.9% had completed treatment as planned, moved to commercial product, or continued treatment. Death, disease progression, or failure to respond occurred for 31.9% of patients. DISCUSSION/SIGNIFICANCE: The population that receives Expanded access treatments is heterogeneous in both demographics and medical conditions. Some successful treatments are continued for years. Many patients complete their treatment, and a minority experience death or disease progression during treatment.