Tyra Biosciences' TYRA-300 shows promise for hypochondroplasia treatment

Tyra Biosciences has released positive results from a preclinical proof of concept study testing its lead drug candidate, TYRA-300, in animal models of hypochondroplasia (HCH).

HCH is a type of skeletal dysplasia, a genetic condition that causes the underdevelopment of limbs and other body parts. There are currently no approved treatments for people living with the condition, which is caused by a genetic mutation in the fibroblast growth factor receptor 3 (FGFR3) gene.

TYRA-300 is an oral inhibitor that selectively targets the N540K mutation in the FGFR3 gene, which is estimated to cause up to 80% of HCH cases.

In a preclinical mouse model of HCH, TYRA-300 was able to significantly increase bone length in the limbs of mice with a FGFR3 mutation. The study also showed that the drug candidate was able to bind the FGFR3 N540K mutated protein and selectively target FGFR3 over other isoforms of FGFR.

These results were presented last week at the 6th Annual Achondroplasia & Skeletal Dysplasia Research Conference (Pharmacon 2024) in Baltimore.

"The new preclinical data presented at Pharmachon 2024 are very encouraging and continue to support our belief that TYRA-300 has the potential to become a best-in-class agent with the potential to address unmet medical needs for people with skeletal dysplasias," said Todd Harris, CEO of Tyra Biosciences. 

The mechanism of action of TYRA-300 makes it a promising candidate to treat multiple forms of skeletal dysplasia where the FGFR3 gene is mutated, including HCH and achondroplasia (ACH), the most common form of dwarfism.

Based on the positive results of the preclinical study, Tyra Biosciences plans to submit an investigational new drug (IND) application in the second half of 2024 to start a phase 2 clinical trial in pediatric achondroplasia.

"The improvements in growth plate function observed in the hypochondroplasia mouse model provide strong proof-of-concept supporting further development of TYRA-300 for hypochondroplasia," said Dr. Michael Bober, VP, Clinical Development and Medical Affairs of TYRA. "This adds to the evidence of TYRA-300 becoming a potential precision medicine for FGFR3 mediated skeletal dysplasia."

Tyra Biosciences was founded in 2018 with the goal of developing drugs targeting the fibroblast growth factor receptor (FGFR). With its small molecule drug discovery platform, called SNÅP, the company focuses on developing therapies for cancer and genetic conditions.

TYRA-300 is currently being evaluated in a phase 1/2 clinical trial in cancer patients with FGFR3 mutations. Two other drug candidates targeting other isoforms of FGFR are currently being investigated in preclinical studies.