Achondroplasia Treatment Landscape Evolves as Competitors Challenge BioMarin's Dominance

The treatment landscape for achondroplasia, the most common form of dwarfism, is undergoing significant transformation as pharmaceutical companies race to develop new therapies and expand existing treatment options. With BioMarin's Voxzogo currently leading the market, emerging competitors are exploring novel approaches to address this rare genetic disorder that affects bone growth in children.

BioMarin Strengthens Voxzogo's Position

BioMarin's Voxzogo (vosoritide) has been at the forefront of achondroplasia treatment since its FDA approval in November 2021 for children aged 5 and older. The drug, which mimics the C-type natriuretic peptide (CNP) to promote bone growth, has recently expanded its reach. In October 2023, the FDA approved Voxzogo for use in children under 5 years of age, making it the first and only approved medicine for achondroplasia starting from birth.

Cristin Hubbard, BioMarin's Chief Commercial Officer, emphasized the importance of early intervention: "Treatment should be initiated as early as possible," citing new data suggesting that starting treatment within the first months of life could lead to better growth improvements. This expansion aligns with current consensus guidelines published in Nature Reviews Endocrinology, arranged by a global consortium of experts and patient advocates.

BioMarin's continued efforts have yielded "more than 6,000 patient-years of data" across Voxzogo's clinical development and real-world use, solidifying its efficacy and safety profile. The drug has demonstrated an improvement in annual growth velocity of 1.57 cm per year at 52 weeks compared to placebo in Phase III trials.

Ascendis Pharma Poised to Challenge with TransCon CNP

As BioMarin consolidates its position, Ascendis Pharma is readying a challenge with its investigational drug TransCon CNP. The FDA is set to make a decision on TransCon CNP on November 30, potentially introducing a new weekly treatment option for children with achondroplasia.

TransCon CNP, also working through the CNP pathway, has shown promising results in its Phase II ACcomplisH study. The drug led to an annualized growth velocity of 5.42 cm per year, compared to 4.35 cm per year in placebo comparators, with a favorable overall safety profile as reported in The Lancet.

Sadaf Javed, manager of Forecasting and Analytics at DelveInsight, noted that TransCon CNP's profile appears "competitive" in terms of efficacy, safety, and convenience. Its once-weekly dosing schedule is considered a "strong differentiator" compared to Voxzogo's daily subcutaneous injections.

Novel Approaches Target Root Cause of Achondroplasia

While BioMarin and Ascendis focus on the CNP pathway, other companies are exploring treatments that address the underlying genetic cause of achondroplasia. BridgeBio is developing infigratinib, a small-molecule drug that blocks the mutant FGFR3 receptor, targeting achondroplasia "directly at its genetic source," according to Justin To, CEO of Skeletal Dysplasias at BridgeBio.

Infigratinib has shown promise in the Phase II PROPEL 2 study, demonstrating a 2.5 cm per year increase in annualized growth velocity at 18 months of follow-up. Notably, the drug also showed significant improvement in body proportionality, a factor not effectively addressed by Voxzogo or TransCon CNP.

BridgeBio is currently conducting the Phase III PROPEL 3 study, with topline data expected in early 2026. If approved, infigratinib would be the first oral treatment option for children with achondroplasia, potentially offering a more convenient alternative to injectable therapies.

As the achondroplasia treatment landscape continues to evolve, patients and healthcare providers can anticipate a broader range of options in the coming years. With approximately 24,000 clinically eligible patients from birth to 18 years of age globally, the market opportunity for effective achondroplasia treatments is substantial, driving ongoing innovation and competition in this rare disease space.