409 Multimodal single-cell sequencing analysis reveals putative tumor reactive population in lifileucel TIL products

摘要: Background Lifileucel is an FDA-approved autologous TIL cell therapy for the treatment of advanced melanoma. We previously presented assessment of TIL drug product (DP) at a single-cell (sc) level from 20 patients. The current study further characterizes lifileucel using DP from 34 patients and analyzes baseline tumor digest T cells from a subset of those patients at an sc level using high-dimension multimodal sequencing. Additionally, we characterize and compare putative tumor reactive (pTR) T cells in baseline tumor and TIL DP.Methods TIL DP from 34 patients (14 responders, 14 stable disease [SD], and 6 progressive disease [PD]) from the registrational melanoma C-144-01 trial (NCT02360579) were analyzed using scRNA and T-cell receptor (TCR) sequencing (Seq). In a subset of patients (3 responders, 3 SD, 1 PD), scRNA- and TCR-Seq were performed on baseline tumor digests sorted for CD45+ cells …