Ractigen Therapeutics has announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) to RAG-21, a novel siRNA therapy targeting the FUS gene, for the treatment of amyotrophic lateral sclerosis (ALS). This designation highlights the critical need for innovative therapies for ALS, particularly for patients with FUS mutations, which represent one of the most severe and rapidly progressing subtypes of the disease.
Targeting FUS-ALS with RAG-21
RAG-21 is specifically designed to address FUS-ALS by leveraging RNA interference (RNAi) to safely and effectively reduce FUS protein levels. Mutations in the FUS gene are associated with an aggressive form of ALS, characterized by early onset and rapid progression. These mutations lead to toxic protein accumulation and mis-localization, ultimately causing motor neuron degeneration. Current therapies like Riluzole and Edaravone offer only modest benefits and are not specific to FUS-ALS, underscoring the need for targeted treatments.
Preclinical Evidence and Mechanism of Action
Preclinical studies have demonstrated RAG-21's potent efficacy and safety in mitigating FUS cytoplasmic mis-localization and aggregation. The therapy is delivered via the SCAD™ platform, which facilitates targeted and durable gene knockdown within the central nervous system (CNS). This mechanism prevents the production of toxic FUS proteins, addressing the underlying pathology of FUS-ALS.
Orphan Drug Designation Benefits
Orphan drug designation is granted by the FDA to drugs intended to treat rare diseases or conditions affecting fewer than 200,000 individuals in the United States. The designation provides companies with incentives, including a 25% tax credit on qualified clinical trials, a seven-year marketing exclusivity, and a waiver of the New Drug Application fee. This support is crucial for advancing the development of therapies for rare diseases like FUS-ALS, where effective treatments are currently lacking.
Ractigen's Commitment to ALS Therapies
"The FDA’s Orphan Drug Designation for RAG-21 underscores the critical need for innovative therapies targeting ALS, particularly for patients with FUS mutations," said Dr. Long-Cheng Li, Founder and CEO of Ractigen Therapeutics. "FUS-ALS represents one of the most severe and rapidly progressing subtypes of ALS, with no curative treatments currently available. We are committed to developing innovative therapies like RAG-21 to provide meaningful treatment options for patients with ALS and other life-threatening rare diseases."
Ractigen previously received FDA Orphan Drug Designation for RAG-17, a similar siRNA molecule targeting SOD1-ALS, demonstrating the company's ongoing commitment to developing RNA-based therapeutics for various subtypes of ALS.
