Preliminary Phase II data from Shanghai-based Abbisko Therapeutics (HKEX: 02256) suggest that lavengratinib (ABSK061), its oral FGFR2/3 inhibitor, produces measurable growth acceleration in children with achondroplasia at the lowest dose tested.
In the ABSK061-202 trial, a Phase II multicenter, open-label, dose-escalation study in children aged 3 to 12 years, all seven participants aged 6 to 12 years in the first cohort (0.064 mg/kg once daily) completed 27 weeks of treatment and achieved a mean increase of +2.4 cm/year in annualized height velocity (AHV) from baseline. Every participant met the predefined responder threshold of at least 25% improvement in AHV from baseline, giving a 100% responder rate. No serious adverse events or treatment discontinuations were reported, and no FGFR1- or FGFR2-associated adverse events — including hyperphosphatemia or corneal toxicity — were observed. Six-month efficacy and safety data from higher-dose cohorts are expected by end of 2026.
Lavengratinib selectively inhibits FGFR2 and FGFR3 while reducing activity against FGFR1. In achondroplasia, gain-of-function mutations in FGFR3 suppress endochondral bone growth; by targeting the receptor directly while sparing FGFR1, Abbisko argues the compound may offer a wider therapeutic window than first-generation pan-FGFR inhibitors. The drug is delivered via a proprietary mini-tablet formulation under 3mm in diameter, designed for ease of administration in young children.
The two approved therapies for achondroplasia — BioMarin's Voxzogo (vosoritide), a once-daily subcutaneous CNP analog approved by the FDA in 2021, and Ascendis Pharma's Yuviwel (navepegritide), a once-weekly subcutaneous pegylated CNP prodrug granted FDA accelerated approval in February 2026 — both act upstream of FGFR3 via NPR-B agonism and require injection.