Competition Heats Up in Achondroplasia Treatment Market

Achondroplasia, a genetic bone disorder affecting approximately one in 20,000 babies, has long been dominated by a single FDA-approved treatment. However, the landscape is poised for change as several pharmaceutical companies race to bring new therapies to market, potentially transforming care for patients with this rare condition.

BioMarin's Voxzogo: The Current Standard of Care

BioMarin's Voxzogo (vosoritide) has been the sole approved treatment for achondroplasia since its initial FDA approval in 2021. The drug, which activates the natriuretic peptide receptor B to restore cartilage development and boost skeletal growth, has seen significant success. In the third quarter of 2024 alone, Voxzogo sales reached $190 million.

Initially approved for children ages 5 and older with open growth plates, Voxzogo received a label expansion in October 2023, broadening its indication to include all children with achondroplasia and open epiphyses. This expansion has further solidified BioMarin's position in the market.

Emerging Competitors and Novel Approaches

Despite Voxzogo's stronghold, several companies are developing alternative treatments for achondroplasia, each employing unique mechanisms of action:

BridgeBio's Infigratinib

BridgeBio is currently enrolling patients for Phase III trials of infigratinib, an oral minitablet formulation of a fibroblast growth factor receptor (FGFR) 1-3-selective tyrosine kinase inhibitor. The company reported positive results from its Phase II PROPEL 2 trial in November 2024, demonstrating increased annualized height velocity and improved height-for-age z scores at the highest dose tested.

Ascendis Pharma's TransCon CNP

Ascendis Pharma has completed Phase II trials with TransCon CNP, an investigational prodrug of C-type natriuretic peptide (CNP) administered once weekly via subcutaneous injection. The company's ACcomplisH trial showed positive results in June 2024, with TransCon CNP stimulating linear growth compared to placebo and demonstrating lower rates of injection site reactions and symptomatic hypotension than observed in Voxzogo trials.

Ribomic's RBM-007

Ribomic is developing RBM-007, an investigational anti-FGF2 aptamer designed to restore defective bone growth. In November 2024, the company released positive interim Phase IIa data, showing an increase in annualized growth rate of up to 3.3 cm/year in some children aged 5 years and older. However, the treatment is still in earlier stages of development compared to its competitors.

Market Outlook and Future Considerations

While these emerging therapies show promise, industry experts predict that BioMarin's Voxzogo will likely maintain its market dominance for the next 4-5 years. The earliest potential approval for a competing treatment is not expected until 2029 or 2030.

As the race for new achondroplasia treatments continues, key considerations include patient preference for oral versus injectable therapies, long-term safety profiles, and the ability of these treatments to increase final adult height in children with achondroplasia. The evolving competitive landscape promises to bring more options to patients and potentially improve outcomes for those living with this rare genetic disorder.