Cartesian Deal Advances Development of In vivo  CAR-T for Autoimmune Diseases

Rare Daily Staff

Cartesian Therapeutics has entered a strategic licensing agreement with WestGene Biopharma aimed at accelerating the development of in vivo  CAR-T therapies for autoimmune diseases, marking a step toward potentially simplifying and expanding access to cell therapy approaches.

The deal reflects growing industry interest in in vivo  cell therapy approaches, which aim to deliver genetic instructions directly into the body to generate engineered immune cells. This approach could reduce cost, complexity, and treatment timelines compared with traditional CAR-T therapies.

The company said the collaboration will combine its mRNA CAR-T payloads, derived from its lead program Descartes-08, with WestGene’s targeted lipid nanoparticle delivery platform. The approach is designed to enable in vivo  generation of CAR-T cells, potentially eliminating the need for complex ex vivo cell manufacturing.

Cartesian plans to initiate a phase 1 dose-escalation trial in the second half of 2026 evaluating in vivo  delivery of its mRNA construct in patients with generalized myasthenia gravis, with initial clinical data expected in the first half of 2027.

Cartesian CEO Carsten Brunn said the partnership builds on the company’s leadership in autologous CAR-T therapies for autoimmune disease and provides a more efficient path to clinical proof of concept. If successful, Cartesian intends to expand the approach across multiple autoimmune indications.

The collaboration leverages prior clinical experience from both companies. WestGene has generated early clinical data supporting its in vivo  CAR-T platform, demonstrating the ability to produce functional CAR-T cells following administration. Reported findings include sustained B-cell depletion and the ability to dose repeatedly without apparent loss of activity. The platform has also shown a favorable safety profile to date, with no dose-limiting toxicities or serious adverse events reported in early studies.

By pairing this delivery system with Cartesian’s validated mRNA constructs, the companies aim to create a scalable approach to CAR-T therapy that could broaden its use beyond current autologous models, which require individualized manufacturing.

In addition to the initial program in myasthenia gravis, Cartesian plans to advance a broader pipeline of mRNA-based therapies through the partnership, including next-generation anti-BCMA CAR constructs and a BCMA-directed T-cell engager. The agreement is intended to provide a framework for rapidly moving multiple candidates into clinical testing.

Financial terms include an upfront payment to WestGene, along with potential development and commercial milestone payments.