BridgeBio (BBIO) Study Result summary

Study design, rationale, and disease background

• Infigratinib is an oral FGFR1-3 inhibitor targeting FGFR3-driven skeletal dysplasias, including achondroplasia and hypochondroplasia, aiming for efficacy and convenience without daily injections.

• Achondroplasia and hypochondroplasia affect 15,000–25,000 children in the US and Europe, causing disproportionate short stature and functional impairments.

• No approved treatments exist for hypochondroplasia in the US.

Safety and tolerability

• Infigratinib was well-tolerated over 18 months, with no serious or treatment-related adverse events or discontinuations.

• Most adverse events were mild, common in the pediatric population, and not linked to the drug; no hyperphosphatemia, ocular events, or accelerated bone age progression were observed.

Efficacy results

• Statistically significant and sustained increase in annualized height velocity (AHV) of +2.5 cm/year at 12 and 18 months (p=0.0015), with 91% of participants showing increased AHV at 18 months and 73% having at least a 25% increase from baseline.

• Statistically significant improvement in body proportionality, with mean upper to lower body segment ratio improving from 2.02 at baseline to 1.88 at month 18 (p=0.001).

• Improvements in growth and proportionality may enhance daily function and quality of life.