TYRA-300 - (SURF302)

September 9, 2026: Tyra Biosciences (NASDAQ: TYRA) reported initial Phase 2 SURF302 results for oral dabogratinib in FGFR3-altered low-grade intermediate-risk non-muscle invasive bladder cancer (LG IR NMIBC), identifying 60 mg once daily as the dose supporting its planned registrational adjuvant strategy. As of August 31, 2026, safety was favorable across 60 mg (n=22) and 50 mg (n=22): most TEAEs were Grade 1/2; Grade 3 treatment-related AEs occurred in 2/44 patients (4.5%), both at 50 mg, with none at 60 mg; no Grade 4/5 TEAEs, no dose reductions or treatment-related discontinuations at 60 mg, and no clinically significant hyperphosphatemia, nail toxicity, or ocular toxicity.

In efficacy-evaluable patients, the 60 mg cohort showed 79% ORR (11/14) and 64% best overall CR (9/14); at 50 mg, ORR was 67% (8/12) and CR 33% (4/12). In single marker lesion patients at 60 mg (n=8), ORR was 100% and best overall CR was 75% (6/8). All 3-month CRs with 6-month assessments remained in response (n=5), and the first participant remained in CR at 12 months.

Tyra plans to complete 60 mg enrollment, start a 70 mg cohort for the ablative setting, and engage health authorities on Phase 3 design and dose selection. In Phase 2 SURF303 in LG UTUC, the first treated patient achieved a 3-month CR at 60 mg with no observed TEAEs.