BioMarin's Promising Results for Next-Generation Achondroplasia Treatment

BioMarin Pharmaceutical Inc. has unveiled encouraging early-stage data for BMN 333, a potential successor to its achondroplasia treatment Voxzogo. The new long-acting C-type natriuretic peptide (CNP) analog demonstrated superior pharmacokinetic properties in a phase 1 study, positioning it as a formidable contender in the evolving landscape of treatments for this form of dwarfism in children.

BMN 333: A Leap Forward in Achondroplasia Treatment

In a phase 1 study involving healthy adult volunteers, BMN 333 exhibited area-under-the-curve (AUC) levels more than three times higher than those observed in other long-acting CNP studies. This pharmacokinetic measure, indicating the total exposure to a drug over time, suggests that BMN 333 could potentially offer enhanced efficacy compared to existing treatments.

Greg Friberg, BioMarin's R&D chief, emphasized the significance of these results during the company's second-quarter conference call, stating that BMN 333's profile demonstrates "a potential best-in-class molecule with the opportunity to drive even greater improvements in growth parameters versus available therapies, and by extension, to further improve measures of health and wellness in children with achondroplasia."

The company reported no safety signals in the phase 1 study, paving the way for further development. BioMarin plans to initiate the dose-finding arm of its phase 2/3 registration-enabling program in the first half of 2026, with a potential launch targeted for 2030, pending positive results.

Market Dynamics and Competitive Landscape

The announcement of BMN 333's promising results comes at a crucial time for BioMarin, as competition in the achondroplasia treatment market intensifies. Voxzogo, approved in 2021, currently stands as the lone medicine on the market for this condition. In the second quarter of 2025, Voxzogo sales reached $221 million, marking a 20% increase year-over-year, with first-half sales totaling $404 million. BioMarin projects 2025 Voxzogo sales to range between $900 million and $935 million, potentially accounting for nearly 30% of the company's revenue.

However, Ascendis Pharma's TransCon CNP (navepegritide) looms on the horizon, with an FDA approval decision expected by November 30, 2025. TransCon CNP has demonstrated comparable results to Voxzogo in a phase 3 trial and offers the advantage of weekly injections compared to Voxzogo's daily regimen.

Additionally, Kyowa Kirin and BridgeBio are advancing infigratinib, a daily oral FGFR3 inhibitor, currently in phase 3 trials for achondroplasia and under investigation for hypochondroplasia, another form of short-limbed dwarfism.

The market's response to BioMarin's announcement was notably positive, with the company's share price increasing by 12% following the news release.