Cartesian Therapeutics (Nasdaq: RNAC) has licensed its mRNA payload technology to China-based WestGene Biopharma in a deal that pairs Cartesian's clinically validated BCMA-directed mRNA CAR-T construct with WestGene's targeted lipid nanoparticle delivery platform. The aim is to eliminate the ex vivo manufacturing step that has constrained conventional CAR-T therapy and create in vivo products. The Maryland-based Cartesian is combining its Descartes-08 mRNA payload — currently in Phase III development for generalized myasthenia gravis — with WestGene's tLNP platform, which has demonstrated preferential uptake in CD8+ T cells in vivo. A Phase I dose-escalation study in patients with generalized myasthenia gravis is expected to initiate in H2 2026, with in-human data anticipated in H1 2027.
Financial terms were not fully disclosed. WestGene will receive an upfront payment and is eligible for development and commercial milestone payments; no amounts were stated.
Descartes-08 is an autologous BCMA-directed mRNA CAR-T therapy designed for outpatient administration without preconditioning lymphodepleting chemotherapy. Unlike conventional DNA-based CAR-T constructs, its mRNA format is non-integrating, avoiding the genomic insertion risks associated with viral vectors. The asset holds Orphan Drug Designation and Regenerative Medicine Advanced Therapy Designation from the US FDA for myasthenia gravis, and Rare Pediatric Disease Designation for juvenile dermatomyositis. Cartesian recently secured USD 150 million in non-dilutive financing from K2 HealthVentures to fund pre-commercial preparations and extend its cash runway through 2028, with topline data from the Phase III AURORA trial expected in Q1 2027.
WestGene's tLNP platform uses proprietary ionizable lipid chemistry that the company describes as conferring preferential uptake in CD8+ T cells following systemic intravenous administration, bypassing the need for antibody conjugation to achieve cell-type selectivity. The platform has been applied clinically: WestGene's nano-adjuvant WGa0401 launched under emergency use authorization, and its lead mRNA asset WGc-043, a tumor vaccine targeting Epstein-Barr virus-associated malignancies, is in Phase I development. In prior in vivo mRNA CAR-T clinical studies, WestGene reported no dose-limiting toxicities, serious adverse events, or ICANS across multiple dosing regimens including up to 14 doses in a single patient, with only one subject experiencing Grade 1 cytokine release syndrome.
Under the collaboration, Cartesian will also advance multiple internally developed next-generation anti-BCMA CAR constructs and a BCMA-directed T-cell engager through the WestGene tLNP delivery framework. Cartesian retains ownership of all mRNA payloads and CAR constructs; WestGene retains platform IP. The deal was facilitated by Chapel Hill-based Uni-Pioneers BioMed, a cross-border biopharma advisory firm.