FDA Clears Ractigen IND Application for Novel saRNA Candidate in Proliferative Vitreoretinopathy

Editor’s Take: saRNA therapy for ocular diseases could be a game-changer; for some types, surgical intervention is the only option.

The U.S. FDA cleared Ractigen Therapeutics’ Investigational New Drug (IND) application for RAG-1C, a small activating RNA (saRNA) drug candidate. RAG-1C can potentially be a first-in-class therapeutic for the prevention and treatment of proliferative vitreoretinopathy (PVR).

How Ractigen is Changing the Game

Ractigen says RAG-1C is designed to be administered by a “one-and-done” intravitreal injection, offering long-lasting anti-fibrotic protection.

PVR is a severe, sight-threatening complication often following rhegmatogenous retinal detachment or other ocular trauma. It is driven by abnormal proliferation and migration of retinal pigment epithelium cells, as well as fibroblasts.

Surgical intervention is the only available option for PVR. However, drawbacks of such surgical procedures include high failure rate, and recurrent retinal detachment.

Second IND Clearance for saRNA Therapy

The FDA’s IND approval, conversely, follows an IND clearance in March 2025 by China’s National Medical Products Administration. As such, RAG-1C is the first saRNA therapy in clinical development for ocular diseases in both the U.S. and China.

The therapy uses a proprietary platform by Ractigen called LiCO, or Lipid-Conjugated Oligonucleotide. This platform delivers a highly specific saRNA reactivating the endogenous p21 (CDKN1A) gene.

RAG-1C induces cell cycle arrest by upregulating p21 protein expression in target ocular cells. This, effectively, inhibits cellular proliferation and myofibroblast transformation, all without cellular toxicity.

“Securing FDA IND clearance for RAG-1C marks a pivotal achievement for Ractigen,” Founder and CEO Long-Cheng Li, MD, said. “[It] reinforces our leadership in RNA activation technology. This global approval validates the safety and therapeutic potential of both RAG-1C and our proprietary LiCO platform. PVR represents a critical unmet clinical need with zero approved drug options. We look forward to initiating our clinical studies to bring this transformative therapy to patients worldwide.”

As Li alluded to, a Phase I clinical trial will be upcoming.