Tyra Biosciences has dosed the first child in BEACH301, its phase 2 clinical study of dabogratinib (TYRA-300), in children with achondroplasia. The drug is the only oral FGFR3-selective inhibitor currently in clinical development for the condition.

Achondroplasia, the most common form of dwarfism, is caused in almost 99 per cent of cases by a gain-of-function mutation in FGFR3. The condition not only leads to disproportionate short stature but can also cause serious health complications, including foramen magnum and spinal stenosis, sleep apnoea and chronic pain. Around 250,000 people worldwide are affected, but treatment options remain limited.

Dabogratinib was discovered through Tyra’s in-house SNÅP drug discovery platform. It has been designed as a once-daily oral therapy with the aim of directly targeting the biology of achondroplasia, while offering a practical treatment option for children and their families.

“Achondroplasia is caused by an alteration in FGFR3, and we believe that precisely targeting the root cause of this condition is the key to transforming care,” said Todd Harris, chief executive of Tyra Biosciences. “Dosing the first child in BEACH301 is more than a milestone for our company — it’s a step toward a future where children with achondroplasia can live healthier, fuller lives.”

The BEACH301 study is a multicentre, open-label, dose-escalation and dose-expansion trial. It is enrolling children aged 3 to 10 who have open growth plates. The primary objectives are to assess safety and tolerability and evaluate changes in annualised growth velocity. Secondary measures include proportionality, pharmacokinetics and changes in height z-score. Participants include children who are treatment-naïve and those who have previously received growth-accelerating therapies. Initial results from a safety sentinel cohort are expected in the second half of 2026.

“Dosing the first child in BEACH301 is a pivotal moment for Tyra as we work to bring next-generation, transformational therapies to areas of profound unmet need,” added Doug Warner, chief medical officer of Tyra. “Dabogratinib is designed as an easy-to-take oral option, offering an improved administration approach for children and their families.”

Patient advocates and clinicians have also welcomed the development. Chandler Crews, founder of The Chandler Project, said: “Families living with achondroplasia need new treatment options, and our community is encouraged to see Tyra stepping into this space with such dedication. Tyra’s approach with dabogratinib is different — it’s designed to specifically target FGFR3 — and that has generated real excitement among families and advocates.”

Dr Klane White, chair of paediatric orthopaedics at Children’s Hospital Colorado, added: “Enrolling and dosing the first child in the BEACH301 trial represents a new landmark in advancing care for children with achondroplasia. As a physician, I see firsthand the advantage of more targeted options, and dabogratinib’s FGFR3–specific approach represents an exciting evolution in how we think about treatment.”