11 March 2026, Abbisko Therapeutics Co., Ltd. ("Abbisko Therapeutics" hereafter, HKEX code: 02256) today announced that its independently developed, highly selective, oral small-molecule FGFR2/3 inhibitor ABSK061, has been granted Rare Pediatric Disease (RPD) designation by the U.S. Food and Drug Administration (FDA) for the treatment of achondroplasia (ACH).

The Rare Pediatric Disease designation program was established by the FDA to encourage pharmaceutical companies to develop innovative therapies for rare and serious diseases that primarily affect individuals younger than 18 by providing financial incentives, thereby expediting the drug approval process. Based on this RPD designation, if the indication is ultimately approved, Abbisko will have chance to receive a Priority Review Voucher (PRV), which can be used to expedite the FDA review of another NDA or Biologics License Application (BLA), or transferred to another NDA applicant, thereby carrying significant strategic and commercial value.

ACH is a rare autosomal genetic disorder that causes severe growth and developmental impairments. Research has shown that the pathogenesis of ACH is driven by aberrant activation of the fibroblast Growth Factor Receptor 3 (FGFR3) caused by FGFR3 gene mutations, which suppress normal endochondral ossification 1. Targeted inhibitors offer the potential to deliver more precise and effective treatment options for ACH patients.

ABSK061, independently developed by Abbisko Therapeutics, is a highly potent and selective small-molecule FGFR2/3 inhibitor. It has demonstrated robust target inhibitory activity, favorable pharmacokinetic properties, and a promising safety profile in preclinical studies. Its oral administration offers significant advantages in terms of convenience and treatment compliance-particularly for pediatric patients-and positions ABSK061 as a potentially valuable therapeutic candidate for children and adolescents with ACH. ABSK061 is currently being evaluated in a Phase II clinical trial in children aged 3 to 12 with ACH.

Reference

1. Savarirayan R, et al. International Consensus Statement on the diagnosis, multidisciplinary management and lifelong care of individuals with achondroplasia. Nat Rev Endocrinol. 2022 Mar;18(3):173-189.

About ABSK061

ABSK061 is a novel, orally bioavailable, highly potent and selective small molecule inhibitor of FGFR2 and FGFR3 independently discovered and wholly-owned by Abbisko Therapeutics. It is the first FGFR2/3 inhibitor to enter clinical trials globally. First-generation pan-FGFR inhibitors demonstrated clinical efficacy in multiple tumors carrying FGFR2/3 variants and have steadily gained regulatory approval globally. However, the therapeutic window of pan-FGFRs and their clinical efficacy have been limited by side effects associated with FGFR1 inhibition. By reducing FGFR1 activity while maintaining potency against FGFR2 and FGFR3, ABSK061 is expected to achieve a wider therapeutic window with improved clinical efficacy as a new-generation of FGFR inhibitors.

About Abbisko Therapeutics

Founded in April 2016, Abbisko Therapeutics Co., Ltd. (HKEX: 02256.HK), is an oncology-focused biopharmaceutical company based in Shanghai that is dedicated to the discovery and development of innovative medicines to treat unmet medical needs in China and globally. The Company was established by a group of seasoned drug hunters with rich research & development and managerial expertise from top multinational pharmaceutical companies. Since its founding, Abbisko Therapeutics has built an extensive pipeline of innovative programs focused on precision oncology and immuno-oncology.

Please visit www.abbisko.com for more information.