TYRA-300 Study is for children aged 3 to 10 with a condition called achondroplasia, which affects growth. The study checks if a drug called TYRA-300 is safe and helps children grow better. TYRA-300 targets a specific protein in the body called FGFR-3 to help with bone growth. To join, children must have open growth plates, which means their bones are still growing. They also need to be able to walk by themselves and take medicine by mouth.

Three groups will be studied: Sentinel Safety Cohort (ages 5-10), Cohort 1 (ages 3-10, no prior growth therapy), and Cohort 2 (ages 3-10, with prior growth therapy). Children with diseases affecting growth or certain eye conditions can't join. This study will take place in multiple centers, and it's important for parents to consent for their child to participate.

• The study involves multiple visits.
• Participation is voluntary and requires parental consent.
• Potential benefits include improved growth, but risks are also possible.