FDA Awards Orphan Drug and Rare Pediatric Disease Designations to the World’s First Cas13X RNA Base-editing Therapy for the Treatment of Congenital Hearing Loss

SHANGHAI and CLINTON (NJ), April 15, 2024 – HuidaGene Therapeutics (“HuidaGene”), a global clinical-stage biotechnology company developing potentially curative genomic medicines, has been granted Rare Pediatric Drug Designation (RPDD) by the U.S. FDA for the Company’s novel mini-dCas13X-mediated RNA adenine base editor (mxABE) therapy to treat children with Q829X mutation in the OTOF (Otoferlin gene)-related hearing loss. The RPDD supplements the orphan drug designation (ODD) previously granted by the FDA on February 29, 2024.

“Granted both ODD and RPDD designations by the FDA, the RNA base-editing therapy for treating congenital deafness, which relies on HuidaGene’s independently developed RNA base editor, is encouraging. Our fourth program receiving both ODD and RPDD designations is a milestone reflecting the team's dedication and scientific innovation recognized by the US FDA,” said Alvin Luk, Ph.D., M.B.A., C.C.R.A., Co-founder, CEO, and Head of Medical of HuidaGene. “Preclinical studies published last year at the Cell-Molecular Therapy entitled ‘RNA base editing therapy cures hearing loss induced by OTOF gene mutation’ (https://www.cell.com/molecular-therapy-family/molecular-therapy/abstract/S1525-0016(23)00596-8), support the potential of our mini-dCas13X RNA base editor therapy to recover hearing to children born with profound hearing loss due to the Q829X mutation of the OTOF gene. Our Company’s commitment supports the team's conviction and belief that innovative treatment for congenital hearing loss is urgently needed. This is the world’s first RNA base-editing therapy receiving both of these designations by the US FDA – let the world witness the China innovation capability!”

The FDA grants ODD to support the development of medicines for rare diseases affecting fewer than 200,000 people in the U.S. Potential benefits of the ODD include accelerated approval review, 7-year post-approval market exclusivity, the federal tax credit for qualified clinical research expenses incurred in the U.S., and a waiver of Prescription Drug User Free Act (PDUFA) fees (currently worth over $4 million). RPDD is granted to drugs in development for the treatment of rare childhood diseases (diseases affecting children 18 years of age and younger) and fewer than 200,000 people in the U.S. Under the RPDD Program, the Sponsor may be eligible for a Priority Review Voucher (PRV) if the drug is initially approved for the disease after the biologics license application (BLA) for which the RPDD was granted. Sponsors of a PRV can redeem the voucher to obtain priority review for any subsequent marketing application for a different product or may be sold to a third party. PRVs have historically commanded prices above $100 million with the highest price paid for a PRV being $350 million.

About HuidaGene

HuidaGene utilizes its proprietary HG-PRECISE^® platform to discover, engineer, and develop CRISPR-based genomic medicine. The Company is advancing clinical programs of HG004 in RPE65-associated inherited retinal disease (granted ODD and RPDD), HG202 CRISPR RNA-editing in neovascular age-related macular degeneration, and the preclinical pipeline, including HG204 CRISPR RNA-editing in neurodevelopmental disease of MECP2 duplication syndrome (granted ODD and RPDD), HG302 CRISPR DNA-editing for Duchenne muscular dystrophy (granted ODD and RPDD), and HG303 CRISPR DNA-editing for Amyotrophic Lateral Sclerosis (ALS). HuidaGene’s extensive intellectual property portfolio positions it as a leader in unleashing the full potential of genome medicines for neurology and ophthalmology. Learn more at huidagene.com or on LinkedIn.