Tyra Biosciences disclosed early Phase II SURF302 results showing selective FGFR3 inhibition with oral dabogratinib in FGFR3‑altered LG IR NMIBC. Safety was generally manageable across 60 mg and 50 mg once‑daily cohorts, with most TEAEs Grade 1–2 and no Grade 4–5 events. In 26 evaluable patients, three‑month ORRs were 79% (60 mg) and 67% (50 mg), with CR rates of 57% and 33%, respectively. Tyra will continue 60 mg enrolment, open a 70 mg cohort, and is advancing separate studies including a paediatric achondroplasia trial.
Tyra Reports Promising Early Phase II SURF302 Results: Dabogratinib Shows Strong Responses in FGFR3‑Altered Low‑Grade NMIBC
For efficacy
Tyra Biosciences has released initial results from its Phase II SURF302 trial investigating oral dabogratinib in patients with FGFR3‑altered low‑grade, intermediate‑risk non‑muscle invasive bladder cancer (LG IR NMIBC).
The dataset provides the first clinical evidence supporting selective oral FGFR3 inhibition in this population and suggests that a 60 mg once‑daily dose may be appropriate for further registrational adjuvant development.
Safety
Safety was evaluated in two dosing cohorts — 60 mg and 50 mg once daily — each enrolling 22 participants. Most treatment‑emergent adverse events (TEAEs) were Grade 1–2. No Grade 4 or 5 TEAEs were reported across either cohort.
Grade 3 TEAEs occurred in 14% of participants in the 60 mg cohort and 9% in the 50 mg cohort. Notably, Grade 3 events considered treatment‑related were reported only in the 50 mg group. At the 60 mg dose there were no treatment‑related discontinuations or dose reductions, and investigators reported no instances assessed as clinically significant hyperphosphatemia, nail toxicity, or ocular toxicity.
Overall TEAEs were described as generally manageable; the most commonly reported events were fatigue, diarrhoea and dry eye.
Efficacy
Twenty‑six participants were evaluable for response across both dose levels. At three months, the objective response rate (ORR) was 79% (11 of 14) in the 60 mg cohort and 67% (8 of 12) in the 50 mg cohort. Complete response (CR) rates at three months were 57% for the 60 mg group and 33% for the 50 mg group. Among patients with a single marker lesion, the three‑month ORR was 100% at the 60 mg dose.
Todd Harris, CEO, Tyra Biosciences: "We are extremely excited to report initial results from SURF302 as we work to advance what we believe could become the first once‑daily oral therapy for patients with low‑grade IR NMIBC. These results belong first and foremost to the patients participating in SURF302 and the investigators and study teams who have made this research possible. We're incredibly grateful for their partnership."
Next Steps
Enrollment in the 60 mg cohort will continue, and a 70 mg cohort will be initiated to evaluate dabogratinib in additional settings. Tyra is also pursuing separate Phase II programmes in low‑grade upper tract urothelial cancer and in achondroplasia. In August 2025, Tyra dosed the first paediatric participant in the BEACH301 dose‑escalation/dose‑expansion trial, which will assess safety and efficacy of dabogratinib in children with achondroplasia.
Note: Original reporting by Clinical Trials Arena, a GlobalData brand.
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