Tyra Biosciences Inc (Nasdaq:TYRA), a clinical-stage biotechnology company focused on developing next-generation precision medicines that target large opportunities in Fibroblast Growth Factor Receptor (FGFR) biology, announced on Monday that the first patient has been dosed in the Phase 2 SURF302 clinical trial of TYRA-300 in low-grade, intermediate risk non-muscle invasive bladder cancer (IR NMIBC).

TYRA-300 is a potential first-in-class, investigational, oral, FGFR3-selective inhibitor designed to minimise the toxicities associated with inhibition of FGFR1, FGFR2 and FGFR4, while being agnostic for FGFR3 gatekeeper mutations. FGFR3 is a frequently altered gene in IR NMIBC, with around 70% of low-grade IR NMIBC showing activating mutations.

SURF302 is an open-label Phase 2 clinical study evaluating the efficacy and safety of TYRA-300 in participants with FGFR3-altered low-grade, IR NMIBC. The study will enrol up to 90 participants at multiple sites primarily in the United States. Participants will be randomised initially to treatment with TYRA-300 at 50 mg once daily (QD) (Cohort 1) or treatment with TYRA-300 at 60 mg QD (Cohort 2). Following a review of efficacy and safety, an additional dosing cohort may be evaluated. The primary endpoint is complete response (CR) rate at three months. Secondary endpoints include time to recurrence, the median duration of response, recurrence free survival (RFS), progression free survival (PFS), safety and tolerability.

TYRA-300 will also be evaluated in paediatric achondroplasia in the BEACH301 Phase 2 study, which is open for enrolment and for which the company now expects first child dosing in the second half of the year.