Shanghai – September 20, 2026 -- Abbisko Therapeutics Co., Ltd. (HKEX: 02256.HK) reported that its oral FGFR2/3 inhibitor lavengratinib achieved a mean increase of 2.4 cm/year in annualized height velocity among children with achondroplasia in the lowest-dose cohort of a Phase II trial, with a 100% responder rate.
Seven children in the first dose cohort completed six months of treatment with no serious adverse events
All seven participants aged 6 to 12 in cohort 1 of the ABSK061-202 study received lavengratinib at 0.064 mg/kg once daily for 27 weeks. Responders were defined as achieving at least a 25% improvement in annualized height velocity from baseline, a threshold every participant in the cohort met.
No FGFR1-linked toxicities such as hyperphosphatemia or corneal damage were observed
Abbisko reported no serious adverse events, treatment discontinuations, or FGFR1/FGFR2-associated side effects to date. The company attributes the tolerability profile to lavengratinib's selectivity for FGFR2 and FGFR3 over FGFR1, a mechanism designed to widen the therapeutic window compared with first-generation pan-FGFR inhibitors already approved for FGFR2/3-mutated tumors.
A sub-3mm mini-tablet formulation targets pediatric dosing compliance
Lavengratinib is delivered via mini-tablets less than 3mm in diameter, versus 8-10mm for conventional tablets, allowing administration with food or drink for young patients. The ABSK061-202 study is a multicenter, open-label, dose-escalation trial enrolling children aged 3 to 12 with achondroplasia, with a planned treatment duration of 78 weeks per participant.
Higher-dose cohorts remain under evaluation ahead of year-end data
Abbisko has completed preliminary safety evaluation across the first three dose cohorts with no safety concerns identified, while participants in higher-dose groups continue treatment. Six-month efficacy and safety results are expected by the end of 2026. Lavengratinib holds both Rare Pediatric Disease Designation and Orphan Drug Designation from the U.S. FDA for achondroplasia, and is the first FGFR2/3 inhibitor to enter clinical trials globally.