HuidaGene Therapeutics Announces Publication of the World's First Guanine Base-Editor

SHANGHAI and CLINTON, N.J., May 18, 2023 /PRNewswire/ -- HuidaGene Therapeutics (辉大基因; HuidaGene), a clinical-stage genome-editing company, today announced the online National Science Review published the comprehensive data from a study of the world's first DNA base editor converting G-to-Y, glycosylase-based guanine base editor (gGBE). Company has filed an international patent application for this base editor and owns the exclusive global rights to the underlying patent.

Current widely-used DNA base editors mainly integrate programmable DNA binding proteins (Cas9, Cas12, or TALE protein variants) with base deaminases (cytidine deaminase or adenosine deaminase variants). There are mainly two types of base editors: ABE (adenine base editor) and CBE (cytosine base editor), which can realize A-to-G and C-to-T transition between such bases ^1-2. However, there is currently no base editor directly edits G or T since deamination of G rarely causes base conversion while T lacks amino groups, making it a challenge to overcome the limitation and to develop new class of base editors. Therefore, there is still a need to edit G or T in many cases.

"Following our publication in Nature Biotechnology early this year of the independently-developed, programmable A-to-Y DNA base editor, AYBE (adenine transversion base editor), we're thrilled that the National Science Review published our paper sharing the comprehensive data on our discovery of the world first guanine-based base editor, gGBE," said Xuan Yao, Ph.D., Co-Founder and Chief Executive Officer of HuidaGene. "CRISPR-Cas9-based CBEs and ABEs can efficiently mediate C-to-T and A-to-G substitutions, respectively. gGBE converting G-to-Y has immense potential for gene-editing drug development, and our successful development of the gGBE further strengthens the Company's intellectual property layout in the global gene editing field."

"Currently, all base editors need the deamination reaction of A or C as the initial step to trigger the subsequent DNA repair process and achieve the goal of base editing. Existing deaminases cannot catalyze guanosine and thymidine in genomic DNA into other nucleosides; therefore, direct editing of guanosine and thymidine is the major bottleneck for gene editing," said Hui Yang, Ph.D., Co-Founder, Chief Scientific Advisor, and Chairman of the SAB at HuidaGene. "Our publication entitled, 'Programmable deaminase-free base editors for G-to-Y conversion by engineered glycosylase', of the world's first guanine-based based editor, gGBE, through our HGPRECISE® platform, has demonstrated guanine editing efficiency up to 90% with lower off-target editing, setting the foundation of developing a new class of base editors based on glycosylases. The new class of engineered glycosylases base editors may further enrich the base editing tool, establish disease models, and develop gene editing therapies."

About HGPRECISE^® Platform
HuidaGene's HGPRECISE® (HuidaGene – Platform for Rational Engineering of CRISPR-Cas Identification by Synergic Expertise) platform enables rapid discovery of Cas proteins using both artificial intelligence (AI) and deep machine learning (ML) of DNA sequencing and assembly prediction from metagenomic database. HGPRECISE® generated Cas proteins have demonstrated superior editing efficiency, lower off-target editing activity compared to widely-used CRISPR-Cas9. The series of engineering transformation, protein evolution, mutational screening and validation on gGBE was performed on the HGPRECISE® platform.

About HuidaGene -辉大基因 
HuidaGene Therapeutics (辉大基因) is a global clinical-stage biotechnology company focusing on discovering, engineering, and developing gene editing tools and gene therapies to rewrite the future of genomic medicine. Based in Shanghai and New Jersey, HuidaGene is committed to addressing patients' needs globally with various preclinical therapeutic programs covering ophthalmology, otology, myology, and neurology. HuidaGene is currently advancing clinical programs in RPE65 mutation-associated inherited retinal dystrophies and various preclinical pipeline, including programs in neovascular age-related macular degeneration, retinitis pigmentosa, hereditary hearing loss, Duchenne muscular dystrophy, and MECP2 duplication syndrome. Those CRISPR-based therapeutics offer the potential to cure patients with life-threatening conditions by repairing the cause of their disease. HuidaGene is committed to transforming the future of genome-editing medicine.
For more information, please visit http://www.huidagene.com 
or follow us on LinkedIn at http://www.linkedin.com/company/huidagene

Reference:
1. Gaudelli, N.M. et al. Programmable base editing of A*T to G*C in genomic DNA without DNA cleavage. Nature 551, 464-471 (2017).
2. Komor, A.C., Kim, Y.B., Packer, M.S., Zuris, J.A. & Liu, D.R. Programmable editing of a target base in genomic DNA without double-stranded DNA cleavage. Nature 533, 420-424 (2016).