Eyes on BridgeBio

Infigratinib met the primary endpoint in the phase 3 Propel 3 trial in achondroplasia. It drug demonstrated statistically significant improvements in annualized height velocity and body proportionality. Analysts characterized the data as a “best-case scenario,” strengthening the case for premium pricing. Regulatory submission is expected in the second half of the year amid increasing competition in the dwarfism market.

BridgeBio - A Second Life After Oncology Setback

BridgeBio Pharma is seeking regulatory redemption for infigratinib, years after its accelerated approval in bile duct cancer was withdrawn.

Originally marketed as Truseltiq for FGFR2 fusion–positive cholangiocarcinoma, the drug lost its oncology indication after confirmatory trial recruitment challenges. But BridgeBio maintained confidence in the molecule, pivoting toward achondroplasia — the most common cause of dwarfism — driven by activating FGFR3 mutations.

Phase 3 Propel 3 Results: Clinically & Statistically Strong

In February, BridgeBio announced that the global phase 3 Propel 3 study met its primary endpoint, showing a statistically significant 2.1 cm/year increase in annualized height velocity (AHV) over placebo after 12 months.

Key findings:

• Least squares mean AHV:

  • Infigratinib: 5.96 cm/year

  • Placebo: 4.22 cm/year

• Body proportionality (children under 8 years):

  • LS mean decrease of 0.05 versus placebo

  • First randomized trial to show statistical improvement in body proportionality

Safety was manageable. Three cases of hyperphosphatemia were reported, all moderate and asymptomatic. No significant adverse events were associated with treatment.

Positioning Against Voxzogo and Emerging Competition

The achondroplasia market is currently led by BioMarin Pharmaceutical’s Voxzogo, approved based on a 1.40 cm/year increase in AHV at 12 months.

Infigratinib’s 2.1 cm/year placebo-adjusted improvement compares favorably. A prior phase 2 study showed mean gains of 2.51 cm/year over 12 months, reinforcing consistency.

Analysts deliberately highlighted the body proportionality results, viewing them as supportive of premium pricing arguments — particularly given the psychosocial and functional implications of disproportionate limb growth.

Regulatory and Commercial Outlook

BridgeBio plans to submit the phase 3 data to regulators in the second half of the year. In parallel, the company is enrolling patients in a separate phase 3 trial for hypochondroplasia, a milder FGFR3-related condition.

Competition remains active:

• Ascendis Pharma is awaiting an FDA decision on TransCon CNP.

• Sanofi exited the space in 2024.

If approved, oral infigratinib could offer:

• The largest AHV improvement observed to date

• Demonstrated improvement in body proportionality

• Broad age-range applicability

For BridgeBio, success here would validate both its precision medicine approach and its willingness to redeploy assets strategically after oncology disappointment.

For more details see here, here, and here.