Tyra reports initial Phase 2 data for oral dabogratinib in bladder cancer
SURF302 trial data show high response rates and manageable safety at 60 mg once-daily, with a registrational study planned for 2027.
On September 9, 2026, Tyra Biosciences announced initial results from SURF302, its Phase 2 study evaluating oral dabogratinib in patients with FGFR3-altered low-grade intermediate-risk non-muscle invasive bladder cancer (LG IR NMIBC).1 The study provided clinical proof of concept for selective oral FGFR3 inhibition and identified 60 mg once-daily as the potential dose supporting Tyra's planned registrational adjuvant development strategy.1
As of the August 31, 2026 data cutoff, initial safety and tolerability results for oral dabogratinib were favorable across the 60 mg QD (n=22) and 50 mg QD (n=22) dose cohorts.1 Most treatment-emergent adverse events were Grade 1 or 2, with Grade 3 TEAEs in 3 participants (14%) at 60 mg and 2 participants (9%) at 50 mg.1 There were no Grade 4 or 5 TEAEs.1
On efficacy, 26 participants were evaluable across the 60 mg QD (n=14) and 50 mg QD (n=12) cohorts.1 For the combined single and multiple marker lesion response at the 3-month assessment, the overall response rate was 79% (11/14) at 60 mg QD and 67% (8/12) at 50 mg QD. For single marker lesion response, the 60 mg QD cohort (n=8) showed a 100% ORR at the 3-month assessment, and the first participant in the study remained in complete response at 12 months and continued on study drug at 14 months.1
Preliminary exposure-response analyses showed an ORR of 86% (12/14) above an AUC threshold of 2500 ng.hr/mL compared with 58% (7/12) below it, with the exposure-response relationship most apparent among participants with multiple marker lesions.1
Tyra plans to complete enrollment in the 60 mg QD cohort, initiate a 70 mg QD cohort for the ablative setting, and engage health authorities on Phase 3 design, with a registrational adjuvant study expected to begin in 2027.1
The company also reported that in its SURF303 study in low-grade upper tract urothelial cancer, the first patient treated achieved a complete response at the 3-month assessment with 60 mg QD, with no observed TEAEs.1 Separately, Tyra said it cleared the fifth dose level with no safety signals in the safety sentinel cohort of BEACH301, its Phase 2 study of dabogratinib in children ages 3 to 10 with achondroplasia.1
Written by readthrough’s AI from the linked primary sources and fact-checked against them automatically before publishing. Not investment advice.