RiboX Therapeutics Ltd., a private, clinical-stage biotechnology company with operations in China, the U.S., and Israel, announced on August 8 that the FDA has cleared its Investigational New Drug (IND) application for RXIM002, clearing the way for a Phase 1 trial of what the company describes as the first circular RNA-based in vivo CAR-T therapy to reach this regulatory stage. RiboX does not trade under a stock ticker, so this is a scientific and regulatory milestone rather than a market-moving event for public investors, but it lands in one of biotech’s most heavily funded areas right now, where several rival approaches have already drawn multibillion-dollar acquisition interest from big pharma.

What “In Vivo CAR-T” Means

In a conventional CAR-T therapy, a patient’s T cells are removed from the body, genetically engineered in a lab to recognize a target on diseased cells, expanded, and infused back in, a process that can take weeks and cost hundreds of thousands of dollars per patient. In vivo CAR-T therapies try to skip that manufacturing step entirely by delivering genetic instructions directly into the patient’s own T cells, so the CAR-T cells are generated inside the body instead of a lab. RXIM002 does this using a targeted lipid nanoparticle, or tLNP, to deliver circular RNA, a more stable, closed-loop form of RNA, encoding instructions for a CAR that targets CD19, a marker found on B cells.

The Platform Behind It

RiboX describes its underlying platform as fully engineered circular RNA combined with a proprietary targeted LNP delivery system, designed to achieve durable protein expression and precise tissue targeting across multiple disease areas beyond this single program, though RXIM002 is the first candidate from that platform to reach FDA IND clearance and the release does not name other pipeline candidates or their development stage.

Target Disease: Immune Thrombocytopenia

RiboX is initially developing RXIM002 for autoimmune cytopenias, starting with immune thrombocytopenia (ITP), the most common of these conditions. ITP is caused by antibodies that mistakenly attack a patient’s own platelets, leading to easy bruising and bleeding risk; the underlying antibodies come from a subset of overactive B cells. By generating CAR-T cells that deplete those B cells from inside the body, RiboX says the treatment could reset a patient’s immune system and produce sustained remission without ongoing drug therapy, though the company describes this as the therapy’s potential and design intent rather than a demonstrated outcome, since the trial has not yet begun enrolling.

The Regulatory Path So Far

Before filing for FDA clearance, RXIM002 was tested in investigator-initiated trials in China in patients with autoimmune disease, with some patients now followed for more than six months. RiboX included the complete safety and early efficacy dataset from those trials, covering every patient treated, in its IND package to the FDA. Based on that data, the agency agreed to let RiboX use an accelerated dose-titration schedule and a subcutaneous formulation in the upcoming trial rather than requiring the more cautious, slower dosing typically required for a first U.S. study of a new cell therapy platform; a subcutaneous injection could eventually allow outpatient dosing instead of the hospital-based infusions conventional CAR-T requires, though that remains a future possibility tied to how the trial performs, not a current feature of an approved product.

The Trial and What the Company Is Saying

The Phase 1 trial, called POPULUS-1, will evaluate the therapy’s safety, pharmacokinetics, pharmacodynamics, and early efficacy, enrolling relapsed or refractory ITP patients first. RiboX CEO Weiyi Zhang called the IND clearance a pivotal milestone for the company and for circular RNA medicines generally, and the release describes RXIM002 as, to the company’s knowledge, the world’s first circRNA-based in vivo CAR therapy to reach FDA IND clearance; that qualifier is the company’s own, since there is no independent registry confirming it holds that distinction.

A Crowded, Well-Funded Field

RiboX’s entry comes into a field that has attracted extraordinary big pharma dealmaking over the past year. AbbVie paid $2.1 billion for Capstan Therapeutics and its mRNA-LNP in vivo CAR-T program, Eli Lilly acquired both Kelonia Therapeutics and Orna Therapeutics in multibillion-dollar deals, and Gilead’s Kite Pharma bought Interius BioTherapeutics for $350 million, among other transactions, with industry trackers estimating roughly $6.6 billion in big pharma acquisitions of in vivo CAR-T companies within about seven months last year alone. Most of those rival programs use conventional linear mRNA or lentiviral delivery rather than circular RNA, and most are targeting cancer indications first rather than autoimmune disease, which makes RXIM002’s combination of a newer RNA format and an autoimmune-first strategy a distinct approach within a crowded and well-capitalized field rather than a direct copy of an existing program.

What’s Next

RiboX has not disclosed financial terms, funding history, or a timeline for when POPULUS-1 will begin enrolling or report initial data, and none is estimated here. As a private company, RiboX’s news is relevant to readers tracking the science and competitive landscape of in vivo cell therapy rather than a specific investable security; the broader in vivo CAR-T space, however, includes several publicly traded acquirers and remains an area of active industry consolidation. This article covers a regulatory and scientific development and is not an investment recommendation.

Sources

• RiboX Therapeutics Announces FDA IND Clearance for RXIM002, the first Circular RNA-Based in vivo CAR Therapy for Autoimmune Cytopenias, PRNewswire, August 8, 2026.
• AbbVie reels in Capstan in $2.1B buyout, charting course for in vivo CAR-T market, cited for background on the in vivo CAR-T competitive and dealmaking landscape.

Editorial Disclosure

This article is based on a press release issued by RiboX Therapeutics Ltd. on August 8, 2026, distributed via PRNewswire, with background context on the broader in vivo CAR-T sector drawn from independent trade press, cited above. RiboX Therapeutics is a privately held company and does not trade under a stock ticker; no securities are discussed in this article. BioTech Stocks Daily was not compensated for this coverage. Statements regarding the therapy’s potential benefits, mechanism, or the company’s characterization of its regulatory or scientific standing are forward-looking or company-sourced and involve risks and uncertainties; the described Phase 1 trial has not yet begun enrolling. This article is for informational and educational purposes only, does not constitute investment advice, and is not medical advice. Consult a qualified healthcare professional for medical guidance. See our full DISCLAIMER.