A multicenter analysis of CAR T-cell toxicities, target antigens, and dosing in solid and hematological malignancies.

e14513 Background: Chimeric antigen receptor T-cell (CAR-T) therapy has showed remarkable efficacy in haematological malignancies and is increasingly investigated in solid tumours. Comprehensive safety data from real world study remain sparse. Understanding toxicity patterns across tumour types is essential for optimising patient selection and management protocols in diverse clinical environments. Methods: We retrospectively analysed the characteristics, treatment parameters, and safety outcomes of consecutive adult patients receiving CAR-T therapy across our institutions between Sept 2024 and Jan 2025, with institutional ethics approval. Data on patient demographics, CAR-T target antigens, dosing, and adverse events were collected. Toxicities were graded per CTCAE v5.0 and ASTCT criteria for CRS/ICANS. Descriptive statistics were used to summarise the findings. Results: 14 patients received CAR-T infusions: 8 solid tumours (Gastric Carcinoma (Ca) n = 2, Parotid Ca n = 1, Rectal Adenocarcinoma n = 1,Pancreatic Ca n = 1, ovarian Ca n = 1, Glioblastoma n = 1, Ewing Sarcoma n = 1)) and 6 haematological malignancies (DLBCL n = 3, B-ALL n = 1, Multiple Myeloma n = 2). Median age was 47.5 years (range 17-68), with 71% males and 64% ECOG PS 1. Five patients (35.7%) had significant comorbidities including hypertension, diabetes mellitus, hypertriglyceridemia, ulcerative colitis, and mixed hyperlipidemia. CAR-T antigen targets were HER2 (n = 2), BCMA (n = 2), B7H3 (n = 3), claudin18.2 (n = 2), mesothelin (n = 1), and CD19 (n = 4), with median dose of 8.2 million cells/kg (range 2.75-10 million/kg). While most infusions were intravenous, one patient with glioblastoma received intracranial delivery via an Ommaya reservoir. Grade 2-3 cytokine release syndrome (CRS) was observed in five patients (35.7%), occurring more frequently in haematological (50%) than solid tumour (25%) cohorts. These events, associated with CD19, B7H3, and Claudin 18.2 targets, were resolved using standard management with tocilizumab and corticosteroids. Immune effector cell-associated neurotoxicity syndrome (ICANS) was limited to a single grade 1 event (7.1%) in the patient receiving intracranial CAR-T. Haematologic toxicities were frequent but manageable, including predominantly grade 1-3 anaemia (50%), leucopenia (50%), and thrombocytopenia (42.9%). One instance of capillary leak syndrome and three cases of transient grade 1-3 hepatotoxicity were noted. Importantly, no nephrotoxicity, endocrine dysfunction, or treatment-related deaths occurred. Conclusions: This early Indian experience demonstrates that CAR-T therapy exhibits manageable toxicity across both solid and haematologicalmalignancies, with CRS rates comparable to international data in haematological tumours but lower in solid tumours. These real world data support expansion of CAR-T with appropriate safety monitoring in oncology setting.