The FDA IND clearance supports the initiation of RiboX's Phase 1 clinical trial evaluating targeted LNP-delivered circular RNA-based in vivo CAR-T therapy for autoimmune cytopenias.

RXIM002 represents the world's first circular RNA-based in vivo CAR-T therapy achieving FDA IND clearance. RiboX expands its clinical-stage pipeline through its proprietary targeted LNP delivery platform.

SHANGHAI and CAMBRIDGE, Mass., Aug. 8, 2026 /PRNewswire/ -- RiboX Therapeutics Ltd. ("RiboX"), a global clinical-stage biotechnology company pioneering fully engineered circular RNA (circRNA) therapeutics, announced today that the U.S. Food and Drug Administration (FDA) has cleared the company's Investigational New Drug (IND) application for RXIM002. RXIM002 is the world's first circular RNA-based in vivo CAR-T therapy delivered by a targeted lipid nanoparticle (tLNP). This marks an important milestone for the field as circRNA-based in vivo CAR-T officially advancing into clinical development.

RXIM002 is an investigational product employing tLNP encapsulated circRNA that encodes a CD19‑targeting chimeric antigen receptor (CAR) for the treatment of autoimmune cytopenias. By delivering circRNA to T cells in vivo, RXIM002 enables durable CAR expression and generating functional CAR-T cells directly within the patient's body. This "in situ generation" approach fundamentally bypasses the complex, costly and time-consuming ex vivo manufacturing processes required by conventional CAR-T therapies, expanding patient access. In autoimmune diseases, deep B cell depletion driven by the in vivo generated CAR-T cells has the potential to induce immune reset and durable drug-free remission.

Prior to the IND submission, RXIM002 was evaluated in investigator-initiated trials (IITs) in China in autoimmune disease patients. Follow-up of these patients are currently ongoing, with some patients exceeding six months. RiboX submitted complete IIT data as part of the IND package to the FDA, encompassing safety and early efficacy results from all treated patients. Based on the integrity and robustness of this full dataset, the agency permitted an accelerated dose-titration scheme and granted subcutaneous formulation as part of clinical development, paving the way for potentially outpatient administration that could fundamentally transform the CAR-T treatment paradigm.

To the company's knowledge, RXIM002 is the world's first tLNP-circRNA in vivo CAR therapy that achieved FDA IND clearance. This milestone validates RiboX's proprietary tLNP platform and further reinforces the company's leadership in precision RNA therapeutics.

"The FDA IND clearance for RXIM002 is a pivotal milestone for RiboX and for the field of circRNA medicines," said Weiyi Zhang, Ph.D., Chief Executive Officer of RiboX Therapeutics. "As the first-in-class circRNA in vivo CAR-T therapy to enter the clinic, RXIM002 exemplifies our ability to translate robust pre-clinical results and rigorous early clinical evidence into an accelerated development path. This achievement brings us closer to delivering a transformative treatment option for patients living with debilitating autoimmune diseases. We are committed to advancing clinical research of RXIM002 across multiple regions worldwide to address the significant unmet needs."

About RXIM002

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.

About POPULUS-1 Study

POPULUS-1 is a Phase 1 clinical trial evaluating the safety, pharmacokinetics, pharmacodynamics, and early efficacy of RXIM002 in patients with relapsed or refractory autoimmune cytopenias. The study will initially enroll participants with relapsed or refractory immune thrombocytopenia (ITP), the most prevalent autoimmune cytopenia, characterized by a low platelet count and an increased risk of bruising and bleeding. ITP is caused by pathogenic autoantibodies driven by aberrant B-cell activation. RXIM002 is being developed to induce transient in vivo CAR T-cell mediated depletion of pathogenic B cells while potentially preserving immune competence.

About RiboX Therapeutics

RiboX Therapeutics is a global, clinical-stage biotechnology company dedicated to discovering and developing circRNA therapeutics with operations in China, US and Israel. RiboX develops proprietary circRNA and targeted LNP platforms that enable durable expression, precision tissue targeting and broad therapeutic applicability across multiple disease areas.

Forward-Looking Statements

This press release contains forward-looking statements regarding the development, regulatory advancement, clinical evaluation, safety, efficacy, and commercial potential of RXIM002 and the Company's circular RNA and targeted lipid nanoparticle platforms. Actual results may differ materially due to various risks and uncertainties. RiboX undertakes no obligation to update forward-looking statements except as required by law.

For Further Information, please visit: http://www.riboxtx.com/