Ascendis Pharma A/S ( ASND )  released topline data on Monday from a trial that included 84 children with achondroplasia, a genetic disorder that causes dwarfism and disproportionate short stature.

In the trial, children treated with once-weekly TransCon CNP demonstrated annualized growth velocity (AGV) superior to placebo.

BioMarin Pharmaceutical Inc’s stock is trading lower in reaction to the data from rival Ascendis.

Also Read: Rare Disease-Focused Ascendis Pharma Stock Falls On Underwhelming Q2 Earnings, Guidance Cut.

William Blair notes that the efficacy of TransCon CNP is comparable to BioMarin’s Voxzogo (vosoritide), which is approved for promoting linear growth in children with achondroplasia and open growth plates (epiphyses).

Early data indicates that TransCon CNP could challenge Voxzogo’s market share by late 2025. Moreover, Ascendis’ TransCon CNP stands out due to its once-weekly dosing schedule and potentially improved safety profile, making it a more appealing option.

The analyst adds, “We think Ascendis’s freedom to operate is still unclear given it may be at risk of infringing on BioMarin’s long-acting CNP patent portfolio, which could restrict Ascendis’ launch or at the very least result in royalties to BioMarin.”

The William Blair analyst emphasizes BioMarin’s first-mover advantage, noting that the company is actively conducting additional trials to broaden Voxzogo’s label.

BioMarin also plans to submit an investigational new drug application for its long-acting CNP in the fourth quarter of 2024. However, competition from TransCon CNP is expected to place continued pressure on Voxzogo’s market share, which may weigh on the stock in the near future.

Earlier this month, BioMarin announced its plans to land $4 billion in revenue by 2027 and target an adjusted operating margin of low-to-mid 40 percent.

Price Action: BMRN stock is down 17.70% at $69.86 at the last check on Monday.

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