RiboX gets FDA IND clearance for circRNA-based in vivo CAR-T for autoimmune cytopenias

The U.S. FDA has cleared RiboX Therapeutics’ IND application for the company’s circular RNA-based in vivo CAR-T therapy delivered by a targeted lipid nanoparticle (tLNP) for the treatment of autoimmune cytopenias.

RXIM002 is a first-in-class, tLNP-delivered circRNA therapy encoding an anti-CD19 CAR. It's designed to generate functional CAR-T cells in vivo to achieve durable, non-integrating CAR-expression. By inducing profound depletion of pathogenic B cells, RXIM002 promotes immune reset and sustained disease remission, offering a potentially transformative, off-the-shelf solution for patients with B-cell-driven autoimmune diseases.

The POPULUS-1 phase 1 clinical trial will evaluate the safety, pharmacokinetics, pharmacodynamics, and early efficacy of RXIM002 in patients with relapsed or refractory autoimmune cytopenias. The study will initially enroll participants with R/R immune thrombocytopenia, the most prevalent autoimmune cytopenia, characterized by a low platelet count and an increased risk of bruising and bleeding.

Prior to the IND submission, RXIM002 was evaluated in investigator-initiated trials (IITs) in China in autoimmune disease patients and the complete IIT data was included as part of the IND package to the FDA, encompassing safety and early efficacy results from all treated patients.

The FDA clearance marks an important milestone for circRNA-based in vivo CAR-T, bringing the emerging modality into the clinic and testing its potential to deliver more durable protein expression than conventional mRNA.