Jiangsu, China — Ractigen Therapeutics announced today that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation to RAG-17, a novel siRNA modality for the treatment of Amyotrophic Lateral Sclerosis (ALS).
“The FDA’s decision to grant orphan drug designation is an important and valuable milestone for RAG-17, and highlights the significant unmet medical need for people living with this severe disease,” Dr. Long-Cheng Li, Founder, President and the CEO said, “We are eager to bring RAG-17 to ALS patients as soon as possible, as we believe this therapy can have significantly higher efficacy in patients with the SOD1 mutation, compared to the other modalities”.
Orphan-drug designation is granted by the FDA to a drug or biologic intended to treat a rare disease or condition, which generally includes a disease or condition that affects fewer than 200,000 individuals in the U.S. The designation provides companies with development incentives, including a seven-year marketing exclusivity from the date of market approval and a waiver of the New Drug Application fee.
ALS is a severely disabling neurodegenerative disease without a curative treatment. Unfortunately, life expectancy of people diagnosed with ALS remains poor and the most patients die from respiratory failure within 3-5 years following diagnosis. Early symptoms typically include muscle cramps, twitching, weakness, and stiffness. Patients inevitably begin to experience problems with movement and speech, which eventually manifests into assisted breathing, paralysis, and inevitable death. Over 50 genes have been linked to ALS in which about 20% of all genetically defined cases are associated with mutation to the SOD1 gene.
RAG-17 is a therapeutic siRNA designed to target and knockdown the expression of SOD1 in patients with pathogenic mutations known to cause ALS. The RAG-17 chemistry is based on Ractigen’s proprietary Smart Chemistry-Aided Delivery (SCAD) delivery platform, in which the siRNA is conjugated to an accessory oligonucleotide (ACO), enabling durable and potent activity in CNS tissues. Based on several preclinical studies, RAG-17 has a significantly higher potency on ALS disease models (e.g., hSOD1G93A mouse model) than benchmark compounds.