NANTONG and SUZHOU,China,Nov. 19,2024 -- Ractigen Therapeutics,a clinical-stage pharmaceutical company dedicated to developing innovative therapies,today announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) to RAG-21,its novel siRNA therapy targeting the FUS gene,for the treatment of amyotrophic lateral sclerosis (ALS).

RAG-21 is an siRNA therapy specifically designed to target FUS-ALS,one of the most aggressive subtype of ALS. By leveraging RNA interference (RNAi),RAG-21 safely and effectively reduces FUS protein levels,addressing the root cause of motor neuron degeneration in FUS-ALS. Preclinical studies have demonstrated its potent efficacy and safety,mitigating FUS cytoplasmic mis-localization and aggregation. As a novel RNA-based therapy,RAG-21 offers renewed hope for improving outcomes in patients suffering from this challenging form of ALS,which currently lacks effective treatment options. This designation marks our second FDA ODD for treating ALS,following RAG-17 for SOD1-ALS,reflecting our commitment to conquering ALS.

Orphan drug designation is granted by the FDA to a drug intended to treat a rare disease or condition,which generally affects 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.

"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."

About RAG-21

RAG-21 utilizes RNA interference to selectively reduce FUS mRNA transcripts. This mechanism prevents the production of toxic FUS proteins and addresses the underlying pathology of FUS-ALS. Delivered via the SCAD™ platform,RAG-21 achieves targeted,efficient,and durable gene knockdown within the CNS. Preclinical data highlight its potential to mitigate motor neuron degeneration and improve disease outcomes,offering hope for patients with this aggressive ALS subtype.

About ALS and FUS Mutations

ALS is a devastating neurodegenerative disease with no cure,significantly impairing patients' quality of life. Most patients succumb to respiratory failure within 2-5 years of diagnosis. Mutations in the FUS gene are associated with a particularly aggressive form of ALS,characterized by early onset and rapid progression. These mutations lead to toxic protein accumulation,mis-localization,and the formation of abnormal inclusions in neurons,ultimately lead to motor neuron degeneration.

Despite progress in ALS drug development,effective treatments remain elusive,especially for FUS-ALS. Current therapies,such as Riluzole and Edaravone,offer only modest benefits and are not specific to FUS-ALS. RNA-based therapeutics,including siRNA,represent a promising strategy by directly targeting disease-driving genes like FUS to address the root cause of the disease.

About Ractigen Therapeutics

A leader in small activating RNA (saRNA) drug development,Ractigen Therapeutics is at the forefront of developing saRNA drugs utilizing RNA activation (RNAa) mechanism to up-regulate endogenous gene expression. This innovative approach involves saRNA targeting specific genes to enhance transcription,thereby restoring normal protein functions. Ractigen's cutting-edge technology is pivotal in treating diseases unaddressable by conventional methods,such as those resulting from epigenetic silencing or gene downregulation. For more information,please visit our website at www.ractigen.com.