RiboX Therapeutics Receives FDA IND Clearance for RXIM002, the First Circular RNA-Based In Vivo CAR Therapy for Autoimmune Cytopenias

August 17, 2026

BioSpace USA

Overview

RiboX Therapeutics has received FDA Investigational New Drug (IND) clearance for RXIM002, a circular RNA (circRNA)-based in vivo CAR therapy targeting autoimmune cytopenias. RXIM002 is the first in vivo CAR therapy designed to deliver CAR genes directly to target cells within the body to suppress autoimmune responses. This IND clearance represents a pivotal step in expanding the applicability of cellular therapies to autoimmune diseases and demonstrates the innovative potential of circRNA technology.

In Depth

Key Findings

RiboX Therapeutics announced it has received Investigational New Drug (IND) clearance from the U.S. Food and Drug Administration (FDA) for RXIM002, its lead therapeutic candidate for autoimmune cytopenias. RXIM002 is a circular RNA (circRNA)-based in vivo (in-body) Chimeric Antigen Receptor (CAR) therapy, marking a groundbreaking milestone as the first in vivo CAR therapy for autoimmune diseases. This IND clearance paves the way for the initiation of a Phase 1 clinical trial for RXIM002.

Technical and Clinical Details

RXIM002 leverages RiboX Therapeutics’ proprietary circular RNA platform. Unlike linear mRNA, circular RNA exhibits superior stability within cells, enabling sustained and prolonged protein expression. RXIM002 is engineered to capitalize on this property by directly delivering and expressing CAR genes in immune cells within the patient’s body. The therapy is designed to target specific autoreactive immune cells, either eliminating or reprogramming them, thereby addressing the root cause of autoimmune cytopenias. Autoimmune cytopenias are a group of conditions where the immune system attacks and destroys a patient’s own blood cells, leading to severe symptoms such as anemia, bleeding, and infections. An in vivo CAR therapy approach circumvents the complex processes of cell collection, ex vivo genetic modification, and reinfusion required for conventional ex vivo CAR therapies, potentially offering significant advantages in terms of ease of administration, cost-effectiveness, and broader patient accessibility. Preclinical data for RXIM002 have demonstrated an excellent pharmacokinetic profile and high efficacy, showing significant improvement in disease models through the selective depletion of autoreactive B or T cells.

Background and Industry Context

CAR therapies have revolutionized cancer treatment, but most current applications involve complex ex vivo procedures. In the autoimmune disease space, existing treatments often provide only symptomatic relief, driving a critical need for disease-modifying or curative approaches. Following the success of CAR-T cell therapies in oncology, their application to autoimmune diseases, particularly those targeting autoreactive B and T cells, has become an active area of research. RiboX Therapeutics’ RXIM002 brings a novel dimension to this field by combining two cutting-edge technologies: circular RNA and in vivo delivery. The structural stability of circRNA is expected to provide more durable therapeutic effects compared to traditional mRNA-based therapies, while the in vivo approach promises substantial simplifications in manufacturing and reduced patient burden.

Strategic Significance and Outlook

The IND clearance for RXIM002 signifies RiboX Therapeutics’ transition into a clinical-stage company and marks the world’s first demonstration of the feasibility of an in vivo CAR therapy for autoimmune diseases. The upcoming Phase 1 clinical trial will evaluate the safety, tolerability, and initial efficacy of RXIM002 in patients with autoimmune cytopenias. Successful development of this therapy could fundamentally transform the treatment paradigm for autoimmune diseases and dramatically improve patients’ quality of life. Furthermore, the establishment of a circular RNA-based in vivo CAR platform technology holds promise for developing next-generation gene therapies across a wide range of cancers and other diseases, making its future progress a keenly watched development in the biotechnology sector.

Source: https://www.biospace.com/press-releases/ribox-therapeutics-announces-fda-ind-clearance-for-rxim002-the-first-circular-rna-based-in-vivo-car-therapy-for-autoimmune-cytopenias

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