Tyra Biosciences has narrowed dabogratinib to three FGFR3-driven indications—intermediate-risk non-muscle invasive bladder cancer, low-grade upper tract urothelial carcinoma (UTUC) and achondroplasia—after dosing over 100 patients across oncology and skeletal dysplasia programs. Multi-species chronic toxicology and targeted Phase 1 data demonstrated mitigated FGFR1/2 toxicities and well-behaved pharmacokinetics, with primary signals of diarrhea and AST/ALT elevations managed by dose reductions.

The company's Phase 2 study in intermediate-risk NMIBC uses a lesion-in-place design, aiming for a ≥70% complete remission rate with durability and an estimated 80%+ disease-free survival in future trials. With FGFR3 positivity above 70% in around 35,000 annual patients, mid-year readouts will assess whether oral dabogratinib can reduce recurrence and decrease cystoscopy and intravesical therapy burden.

In the BEACH301 pediatric trial, dabogratinib is testing adult equivalent doses of 10, 20, 30 and 40 mg to target annualized height velocity above 7 cm, contrasted against reported 6–6.5 cm gains in competing Phase 2 datasets. The company expects second-half data to validate whether selective FGFR3 engagement can deliver incremental growth and improved functional outcomes over CNP-based therapies.

Tyra plans to initiate the registrational SURF303 trial in low-grade UTUC following IND clearance, targeting initial complete remission as the primary endpoint and evaluating kidney preservation with ongoing therapy. With up to 40% of patients at risk of nephrectomy under current management, the oral FGFR3 inhibitor aims to offer a kidney-sparing alternative.