NANTONG, China, July 31, 2026
Ractigen Therapeutics has received U.S. Food and Drug Administration (FDA) clearance of its Investigational New Drug (IND) application for RAG-1C, a first-in-class small activating RNA (saRNA) therapeutic candidate being developed for the prevention and treatment of proliferative vitreoretinopathy (PVR). The regulatory milestone enables Ractigen to advance RAG-1C into U.S. clinical development and follows an earlier IND clearance from China’s National Medical Products Administration (NMPA/CDE) in March 2025. According to Ractigen, the dual regulatory clearances position RAG-1C as the first saRNA therapy for ocular disease to enter clinical development in both the United States and China. The investigational therapy uses the company’s proprietary LiCO™ delivery platform to activate the endogenous p21 (CDKN1A) gene, with the goal of providing sustained anti-fibrotic activity in patients at risk of developing PVR following retinal detachment.
FDA Clearance Opens U.S. Clinical Path for RAG-1C
The FDA IND clearance represents an important clinical and regulatory milestone for Ractigen’s RNA activation platform and clears the way for an upcoming Phase I clinical trial of RAG-1C. The study is expected to evaluate safety, tolerability, pharmacokinetics and preliminary efficacy in patients undergoing surgery for retinal detachment who are considered at high risk of developing PVR. The disease is a serious complication associated with rhegmatogenous retinal detachment (RRD) and ocular trauma, driven by abnormal proliferation and migration of retinal pigment epithelium cells and fibroblasts. According to the company, PVR affects approximately 5% to 10% of RRD cases and as many as 40% of severe ocular trauma cases. Importantly, there are currently no FDA-approved pharmacological treatments for PVR, leaving surgery as the primary treatment approach and creating a significant unmet need for therapies capable of preventing disease progression and recurrent retinal detachment.
RAG-1C Uses saRNA to Activate p21 and Target Fibrosis
RAG-1C represents a differentiated RNA therapeutic strategy because it is designed to activate, rather than silence, a therapeutically relevant gene. The candidate uses Ractigen’s proprietary LiCO™ (Lipid-Conjugated Oligonucleotide) platform to deliver a highly specific saRNA targeting activation of the p21 gene. By increasing p21 protein expression in targeted ocular cells, RAG-1C is designed to induce cell-cycle arrest and inhibit abnormal cellular proliferation and myofibroblast transformation without cellular toxicity. The therapy is administered through intravitreal injection and is being developed with the potential to provide long-lasting anti-fibrotic protection through a single intraoperative administration. Ractigen describes LiCO as a non-LNP conjugated delivery technology optimized for tissue-targeted delivery, with preclinical and clinical program experience supporting ocular tolerability and limited systemic exposure.
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Dual IND Clearances Support Global saRNA Development Strategy
The U.S. regulatory milestone builds on RAG-1C’s China IND clearance received in March 2025, establishing a pathway for coordinated clinical development across two major pharmaceutical markets. Ractigen believes the dual clearances further validate both RAG-1C and its RNA activation technology, while strengthening the company’s position in the emerging field of small activating RNA therapeutics. PVR remains a major cause of unsuccessful retinal detachment repair and can result in membrane formation on the retinal surface, tractional retinal detachment and permanent vision loss. By targeting the biological mechanisms responsible for pathological cellular proliferation and fibrosis, RAG-1C could introduce a new pharmacological approach for a condition currently managed primarily through surgical intervention. The program also demonstrates the broader potential of Ractigen’s proprietary RNA delivery technologies as the clinical-stage biopharmaceutical company advances therapeutic candidates across ocular diseases, oncology, neurological conditions and genetic disorders. The upcoming Phase I study will provide the first clinical evidence needed to determine whether RAG-1C’s targeted gene-activation strategy can translate into a safe and potentially effective treatment for patients at risk of PVR.
Source: Ractigen Therapeutics press release
