FDA Grants Ascendis Accelerated Approval for Achondroplasia Drug

Rare Daily Staff

The U.S. Food and Drug Administration has granted accelerated approval to Ascendis Pharma’s Yuviwel, the first once-weekly therapy to help children with the rare condition achondroplasia, the most common form of dwarfism, grow taller.

The approval covers children 2 years of age and older who have open growth plates.

The drug is the first treatment in its class to be given weekly and to provide continuous systemic exposure to a growth‑regulating signaling molecule, C‑type natriuretic peptide (CNP), over the full dosing interval.

Achondroplasia is a lifelong genetic condition that affects how bones grow, especially in the arms and legs, and can lead to health issues such as spine problems, sleep‑disordered breathing, ear infections, and chronic pain.​

Yuviwel is a prodrug based on the natural hormone CNP, designed to dampen overactive FGFR3 growth‑control signaling in people with achondroplasia by slowly releasing active CNP throughout the body to support more typical bone growth.

In clinical trials that followed children for up to a year, those who received once‑weekly Yuviwel grew faster on average than those who received placebo, with an increase in annualized growth velocity of about 1.5 centimeters (a little more than half an inch) of extra height per year, and also showed improvements in leg alignment and body proportions.

Because the FDA granted accelerated approval, the decision is based on how much the drug increased growth rate, a measure called annualized growth velocity, and Ascendis must complete additional studies to show that this faster growth translates into longer‑term health benefits for children, such as fewer complications or surgeries.

The overall safety profile was similar to placebo in the studies conducted so far, with no treatment‑related serious side effects and low rates of injection‑site reactions and low blood pressure events.

The most common side effects seen with Yuviwel include reactions where the shot is given, such as redness, itching, bruising, or pain, and the drug can sometimes cause low blood pressure, which may show up as dizziness, fatigue, or nausea.

Ascendis said it expects Yuviwel to be available in the United States in the early part of the second quarter of 2026 through prescribing physicians, and it plans to offer support services through its Ascendis Signature Access Program, including help navigating insurance coverage and potential financial assistance for eligible families.

With this approval, the FDA also granted Ascendis a Rare Pediatric Disease Priority Review Voucher.