Bridging preclinical development and clinical manufacturing: a translational GMP-Platform for lentiviral vector production in academic CAR T-Cell therapy

Abstract

The manufacturing of lentiviral vectors (LV) under Good Manufacturing Practices (GMP) remains a critical bottleneck limiting the clinical translation of academic CAR T-cell therapies. To address this challenge, we established and validated an integrated GMP facility (ViPro-IBiS-UPRC) for aseptic LV production within a public healthcare setting. A stepwise optimization strategy was implemented to bridge preclinical development and GMP manufacturing, including refinement of transfection conditions, vector harvest timing, and scale-up surface transition. GMP-compliant production processes and quality control (QC) frameworks were subsequently developed and validated for HEK293T Lenti-X master and working cell banks (MCB/WCB) and for LV manufacturing. Cell banks demonstrated high viability (≥94%), robust expansion capacity, confirmed identity by DNA fingerprinting, and absence of microbial and viral contaminants, including adventitious and endogenous retroviruses. GMP-produced LV batches achieved functional titers ranging from 9.95 × 107 to 3.07 × 108 TU/mL and fulfilled all release criteria, including sterility, absence of mycoplasma, endotoxins, and replication-competent lentivirus. Residual host cell DNA and protein levels remained within international regulatory predefined acceptance thresholds. Stability studies demonstrated preservation of vector functionality up to 12 months under cryopreservation conditions. Following regulatory inspection, ViPro-IBiS-UPRC obtained GMP certification from the Spanish Agency of Medicines and Medical Devices (AEMPS) for LV production, supporting the manufacture of CARTemis-1, an anti-BCMA CAR T-cell product under clinical evaluation in relapsed multiple myeloma patients. Collectively, this work establishes a GMP-compliant academic platform for scalable LV manufacturing, enabling decentralized, cost-effective, and clinically compliant supply. This point-of-care manufacturing model strengthens the accessibility of academic CAR T-cell therapies within public healthcare systems.