RAG-18 receives FDA orphan drug designation for Duchenne, Becker MD

The U.S. Food and Drug Administration (FDA) has granted orphan drug designation to RAG-18 and it is being developed as a potential treatment for both Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD).

RAG-18 is a small activating RNA therapy (saRNA) from Ractigen Therapeutics that aims to counteract the deficiency of dystrophin, the hallmark of both diseases.

Orphan drug status is designed to encourage companies to develop treatments for rare diseases, which are diseases that affect fewer than 200,000 people in the United States. The drugs receive a number of benefits, including seven years of market exclusivity after approval and exemption from certain fees.

This announcement came about a month after the FDA granted DMD a rare pediatric disease designation, which is also intended to encourage the development of therapies for rare diseases, but with a particular focus on those that primarily affect children.

“The FDA orphan drug designation is a critical achievement for RAG-18. Together with the recent pediatric rare drug designation, this reflects our groundbreaking work in the field of RNA activation and underscores our commitment to truly improving the lives of people with rare diseases,” said Dr. Long-Cheng Li, founder and CEO of Ractigen, in a company press release.

“This recognition reinforces our determination to advance the development of RAG-18 with the goal of bringing innovative and life-changing treatments to DMD and BMD patients around the world,” Li added.

The orphan drug status follows the classification as a rare pediatric disease for DMD

DMD and BMD are both caused by mutations in the DMD Gene that encodes a protein called dystrophin. In BMD, a type of muscular dystrophy in which skeletal and cardiac muscle slowly break down, this protein is generally present in low amounts or does not function properly. In DMD, the most common form of the genetic disease that causes progressive deterioration of muscle fibers, dystrophin is usually completely absent.

According to Ractigen, RAG-18 is a “first of its kind saRNA” designed to UTRN gene – which encodes a protein called utrophin – in muscle cells.

Utrophin is structurally and functionally similar to the dystrophin protein, which is normally produced during embryonic development. Scientists believe that increasing utrophin levels in adulthood may compensate for dystrophin deficiency in DMD patients.

The experimental therapy is intended to stimulate the production of the protein and compensate for the lack of dystrophin in all DMD patients, regardless of the specific mutation site on the DMD Gene.

Preclinical data demonstrated that RAG-18, when administered by injection under the skin (subcutaneously) using proprietary lipid-conjugated oligonucleotide technology, was able to attenuate muscle damage, supporting its therapeutic potential in DMD patients.