(P 448) OVERCOMING CHALLENGES IN ULTRA-RARE SARCOMAS: A CENTRALIZED BIOBANK FOR EPITHELIOID HEMANGIOENDOTHELIOMA AS A RESOURCE TO ACCELERATE DISCOVERY

Objective: Epithelioid Hemangioendothelioma (EHE) is an ultra-rare vascular sarcoma with an estimated incidence of less than 1 per million people.1 The rarity and heterogeneity of EHE presents significant challenges in basic, translational, and clinical research with very limited access to tissue and fluid specimens.

Development of EHE model systems is essential to advance therapeutic discovery. Presently, there remain too few disease models, and no published human cell lines. EHE model development is an urgent need that will result in better understanding of disease phenotypes, inform biomarker development, and identify therapeutic targets in EHE.

To address this need, the EHE Foundation initiated the EHE Biobank, a central biorepository of specimens including fresh tumor tissue from surgeries, archived tumor tissue, serosal effusions, blood, and saliva, making samples available for ethical research and model development.

Methods: EHE patients were informed about the opportunity to donate biospecimens by the EHE Foundation. Patients provided electronic informed consent. The EHE Biobank facilitated specimen procurement requests with patients’ medical institutions at the request of the patient. A minimal clinical dataset was maintained; specimens and data were de-identified. The Foundation sought partners for model development and drug discovery through its collaborative research network.

Results: Since initiation of the Biobank in 2021, 98 participants consented, 112 specimens have been collected. Of these, 83 are fresh, frozen, or paraffin-embedded tissue, 17 serosal fluids, and 15 blood samples. 5 participants donated EHE tumor tissue posthumously. To date, 21 specimens have been distributed to researchers and 4 models are in development.

Conclusion: Patient organizations are capable to initiate and conduct ethical research leveraging professional resources and partners. People diagnosed with EHE are uniquely positioned to work together within patient organizations to accelerate model and biomarker development by donating human specimens, making ultra-rare biospecimens readily available for research.