Tyra Biosciences Reports Initial Phase 2 SURF302 Results Supporting the First Potential Oral Innovation in LG IR NMIBC with Dabogratinib
Early SURF302 data indicate promising activity and tolerability for once-daily oral dabogratinib and support Tyra’s move toward Phase 3 planning.
Rhea-AI Summary
Tyra Biosciences (TYRA) reported initial Phase 2 SURF302 results showing oral dabogratinib achieved a 79% overall response rate and 64% best overall complete response rate at the 60 mg once-daily dose in FGFR3‑altered low-grade intermediate-risk non-muscle invasive bladder cancer as of August 31, 2026.
In the 60 mg cohort, single marker lesion patients (n=8) had a 100% overall response rate and 75% best overall complete response rate, with all 3‑month complete responses that reached 6 months remaining in response (n=5). Safety across 60 mg (n=22) and 50 mg (n=22) was favorable, with most events Grade 1–2, Grade 3 treatment-related adverse events in 4.5% of participants (2/44) and none at 60 mg, and no Grade 4–5 events, dose reductions or treatment-related discontinuations at 60 mg. Exposure–response analyses showed 86% ORR above an AUC threshold versus 58% below, supporting 60 mg for adjuvant use and exploration of a 70 mg cohort, while the first SURF303 LG UTUC patient achieved a 3‑month complete response on 60 mg with no observed TEAEs.
Positive
- 60 mg QD SURF302 efficacy: 79% ORR and 64% best overall CR rate in evaluable FGFR3‑altered LG IR NMIBC patients (n=14).
- Single marker lesion response: at 60 mg QD, 100% ORR and 75% best overall CR rate in single marker lesion patients (n=8).
- Durability of response: all 3‑month CRs with 6‑month assessments remained in response (n=5), with the first participant in CR at 12 months and on drug at 14 months.
- Favorable safety profile: Grade 3 treatment-related AEs in 2 of 44 participants (4.5%), none at 60 mg QD, and no Grade 4 or 5 TEAEs.
- Tolerability at 60 mg QD: no dose reductions or treatment-related discontinuations; no clinically significant hyperphosphatemia, nail toxicity or ocular toxicity observed.
- Exposure–response signal: ORR 86% (12/14) above AUC 2500 ng·hr/mL versus 58% (7/12) below, guiding dose optimization and Phase 3 strategy.
Negative
- Grade 3 TEAEs: occurred in 14% of participants at 60 mg QD (3/22) and 9% at 50 mg QD (2/22), though Grade 3 treatment-related AEs were only at 50 mg.
- Lower efficacy at 50 mg QD: combined-lesion cohort showed 67% ORR and 33% CR rate (n=12), below the 60 mg cohort performance.
News Explained
This remains an initial clinical update rather than a completed Phase 3 program: at
Sources and calculations
- Tyra Biosciences initial SURF302 results release (2026-09-09)
- Tyra Biosciences second-quarter 2026 fundamentals (2026Q2)
- Available liquidity against the last reported quarterly operating outflow, in days at that rate $73,835,000 / ($31,076,000 / 91) = 216.2 days
Details
Market reaction after Phase 2 clinical data: TYRA -21.40%
Following this news, TYRA has declined 21.40%, reflecting a significant negative market reaction. Argus tracked a peak move of +16.6% during the session. Argus tracked a trough of -33.1% from its starting point during tracking. Our momentum scanner has triggered 9 alerts so far, indicating moderate trading interest and price volatility. The stock is currently trading at $21.01. Trading volume is exceptionally heavy at 33.4x the average, suggesting significant selling pressure.
Data tracked by StockTitan Argus (15 min delayed). Upgrade to Gold for real-time data.
Key Figures
- Overall response rate
- 79%
- 60 mg QD combined single and multiple marker lesion cohort, n=14
- Best overall response CR rate
- 64%
- 60 mg QD combined single and multiple marker lesion cohort, n=14
- Overall response rate
- 100%
- 60 mg QD single marker lesion cohort, n=8
- Best overall response CR rate
- 75%
- 60 mg QD single marker lesion cohort, n=8
- Grade 3 treatment-related adverse events
- 4.5%
- 2 of 44 participants across 50 mg QD and 60 mg QD cohorts; none at 60 mg QD
- Exposure-response ORR
- 86% vs. 58%
- Above vs. below the AUC threshold of 2500 ng‧hr/mL
- Planned dose cohort
- 70 mg QD
- Planned cohort for evaluation in the ablative setting
- Complete response
- 3-month CR
- First participant treated in Phase 2 SURF303 for LG UTUC
Previous Clinical trial Reports
-
Initiated SURF302 dosing at 50 mg and 60 mg once-daily in IR NMIBC
24h Move is the share-price change in the day after each event; other market factors may also have contributed.
Key Terms
fgfr3 medical
nmibc medical
orr medical
teae medical
auc medical
AI-generated analysis. How Rhea-AI works. Not financial advice.
TYRA's mission is to make dabogratinib the clear first-line treatment choice for patients with LG IR NMIBC
Favorable safety and tolerability results support chronic dosing potential
No clinically significant hyperphosphatemia, nail toxicity or ocular toxicity; low frequency of transaminase TEAEs (<
First patient treated in Phase 2 SURF303 study in LG UTUC achieved a 3-month CR with 60 mg QD
Conference call today, September 9, at 8 am ET to discuss results
Approximately
"We are extremely excited to report initial results from SURF302 today as we work to advance what we believe could become the first once-daily oral therapy for patients with low-grade IR NMIBC," said Todd Harris, Ph.D., Chief Executive Officer of TYRA Biosciences. "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."
"SURF302 has effectively given us two studies in one, informing dual settings in which dabogratinib could potentially be used. Patients with a single marker lesion — whose minimal disease most closely mirrors the adjuvant setting (where no tumor is left behind) and historical marker lesion studies — achieved a
"As a community-based urologist, one of the greatest challenges isn't identifying patients who could benefit from therapy—it's that many choose surveillance because the burden of repeated catheterization and intravesical treatments outweighs the perceived benefit," said Mark Silva, M.D., Greater Boston Urology. "Too often, those patients are simply waiting to recur. A well-tolerated once-daily oral therapy could fundamentally change that conversation – giving patients an option they may be more willing to accept, and giving physicians the chance to intervene before the next recurrence rather than react after it occurs."
Initial safety and tolerability results. 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. Most treatment-emergent adverse events (TEAEs) were Grade 1 or 2, with Grade 3 TEAEs in 3 participants (
- At 60 mg QD, there were no dose reductions or treatment-related discontinuations.
- No clinically significant hyperphosphatemia, nail toxicity, or ocular toxicity was observed.
- TEAEs were generally manageable.
- Transaminase TEAEs were observed at low frequency (<
10% ). - The most frequently reported TEAEs at 60 mg QD were fatigue, diarrhea and dry eye. Diarrhea was generally Grade 1, transient, and limited.
- Transaminase TEAEs were observed at low frequency (<
Initial efficacy results. As of the August 31, 2026 data cutoff, 26 participants were evaluable for efficacy across the 60 mg QD (n=14) and 50 mg QD (n=12) cohorts (participants who received study treatment and had undergone at least the month 3 disease assessment). All responses below are subject to change with continued treatment and follow-up.
Combined Single and Multiple Marker Lesion Response
60 mg QD Cohort (n=14) | 50 mg QD Cohort (n=12) | ||
3-Month | BOR | 3-Month Assessment and BOR | |
ORR | |||
CR | |||
Partial | |||
#Best overall response CR includes the initial 60 mg participant with a 3-month PR who converted to CR at the 6-month assessment. No |
Single Marker Lesion Response
60 mg QD Cohort (n=8) | All Doses, 50 mg and 60 mg Pooled | |||
3-Month | BOR | 3-Month | BOR | |
ORR | ||||
CR | ||||
PR | ||||
#Best overall response CR includes the initial 60 mg participant with a 3-month PR who converted to CR at the 6-month assessment. No |
- All 3-month CRs with 6-month assessments remained in response at 6 months (n=5).
- The first participant in the study remained in CR at 12 months and continued on study drug at 14 months.
Dose-optimization and registrational strategy.
- Preliminary exposure-response analyses across the 50 mg QD and 60 mg QD cohorts showed an ORR of
86% (12/14) among participants with a target steady-state exposure above the AUC threshold of 2500 ng‧hr/mL, compared with58% (7/12) among participants below the threshold. The exposure-response relationship was most apparent among participants with multiple marker lesions, while responses in participants with a single marker lesion occurred across the observed exposure range — supporting 60 mg QD in the planned adjuvant setting, where disease burden is minimal, and the evaluation of a higher dose in the ablative setting. - TYRA plans to complete enrollment in the 60 mg QD cohort and initiate a 70 mg QD cohort to explore dabogratinib in the ablative setting. TYRA also plans to engage health authorities on Phase 3 study design and dose selection and, subject to that feedback, to continue preparations for a planned registrational adjuvant study.
Initial observation from SURF303 in LG UTUC. In SURF303, TYRA's Phase 2 study evaluating oral dabogratinib in patients with low-grade upper tract urothelial cancer (LG UTUC), the first patient treated achieved a complete response at the 3-month assessment with 60 mg QD, with no observed TEAEs and remained on study drug as of the August 31, 2026 data cutoff.
Conference Call and Webcast
TYRA is hosting a conference call and webcast today, September 9, 2026, at 8:00 am ET to discuss the initial SURF302 study results with oral dabogratinib. Participants may access a live webcast of the call and the associated slide presentation following the conclusion of the call on the "For Investors" page of the TYRA website at https://ir.tyra.bio. To participate via telephone, please register in advance at this link. Upon registration, all telephone participants will receive a confirmation email detailing how to join the conference call, including the dial-in number along with a unique passcode and registrant ID that can be used to access the call. A replay of the conference call and webcast will be archived on the Company's website for at least 90 days.
About SURF302
SURF302 (NCT06995677) is a Phase 2, multicenter, open-label clinical study evaluating the efficacy and safety of oral dabogratinib in adults with FGFR3-altered low-grade IR NMIBC. The study includes dose-optimization cohorts and is designed to support the potential development of dabogratinib as an adjuvant therapy. Key endpoints include best overall response, complete response at three months, time to recurrence, duration of response, recurrence-free survival, progression-free survival, safety and tolerability. For more information, please visit the Patients page of the Company's website at https://tyra.bio/patients/ or https://clinicaltrials.gov/study/NCT06995677.
About Intermediate-Risk Non-Muscle Invasive Bladder Cancer (IR NMIBC)
Bladder cancer is one of the most common cancers in
About Dabogratinib
Dabogratinib is TYRA's lead precision medicine candidate stemming from its in-house SNÅP platform. Dabogratinib is an investigational, oral, FGFR3-selective inhibitor currently in Phase 2 development for the treatment of urologic cancers and skeletal dysplasias, specifically low-grade upper tract urothelial carcinoma (LG UTUC), IR NMIBC and achondroplasia (ACH). TYRA believes dabogratinib was the first orally available, FGFR3-selective inhibitor to enter clinical development, and it has been studied in more than 200 individuals to date across multiple clinical and healthy volunteer studies. Oral dabogratinib is currently advancing in three Phase 2 clinical trials: SURF303 in LG UTUC, SURF302 in IR NMIBC and BEACH301 in ACH. The FDA has granted Orphan Drug Designation and Rare Pediatric Disease Designation to oral dabogratinib for the treatment of achondroplasia.
About Tyra Biosciences
Tyra Biosciences, Inc. (Nasdaq: TYRA) is a clinical-stage biotechnology company focused on developing next-generation precision medicines that target large opportunities in FGFR biology. TYRA's in-house precision medicine platform, SNÅP, enables rapid and precise drug design through iterative molecular SNÅPshots that help TYRA design and predict which candidates may demonstrate the highest potency, selectivity and tolerability in the clinic. TYRA's expertise in FGFR biology has created a differentiated pipeline with clinical-stage programs in targeted oncology and genetically defined conditions. TYRA's lead precision medicine stemming from SNÅP, oral dabogratinib, is a potential first-in-class selective FGFR3 inhibitor in development for LG UTUC, IR NMIBC and ACH. TYRA is also developing TYRA-430, an oral, investigational FGFR4/3-biased inhibitor for FGF19+/FGFR4-driven cancers, in the SURF431 study for advanced hepatocellular carcinoma, and TYRA-200, an oral, investigational FGFR1/2/3 inhibitor, in the SURF201 study for metastatic intrahepatic cholangiocarcinoma. TYRA is based in Carlsbad, California. For more information, please visit www.tyra.bio and engage with TYRA on LinkedIn.
Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Statements contained in this press release that are not historical facts are forward-looking statements, including, but not limited to, statements regarding: the potential safety, efficacy, tolerability and therapeutic benefits of dabogratinib; the potential for dabogratinib to change the treatment paradigm for patients with FGFR3-altered LG IR NMIBC, to reduce recurrence, or to become a first-in-class once-daily oral therapy for FGFR3-altered LG IR NMIBC; the interpretation, significance and clinical implications of the initial SURF302 results, including observations regarding overall response rate, complete response, durability of response, dose-response relationships, exposure-response analyses and safety; the clinical significance of the initial response observed in the SURF303 study; the continued clinical development of dabogratinib, including continued enrollment at 60 mg, evaluation of the 70 mg dose cohort, and discussions with the U.S. Food and Drug Administration and other global health authorities regarding dose selection and Phase 3 study design; the timing, design and initiation of future clinical trials, including a potential registrational adjuvant study; and the potential commercial opportunity for dabogratinib.
These forward-looking statements are based on TYRA's current expectations and beliefs and are subject to a number of risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements. These risks and uncertainties include, without limitation: initial or interim results of a clinical trial are not necessarily indicative of final results and one or more of the clinical outcomes may materially change as patient enrollment continues, following more comprehensive reviews of the data, as follow-up on the outcome of any particular patient continues and as more patient or final data becomes available; preliminary pharmacokinetic, pharmacodynamic and exposure-response analyses may not be predictive of future clinical outcomes or later-stage studies; early clinical observations from SURF303, including those from an individual participant, may not be predictive of future results; the safety and efficacy observed to date may not continue in ongoing or future studies; TYRA's ability to successfully enroll, conduct and complete its clinical trials; the timing and outcome of interactions with the FDA and other regulatory authorities on TYRA's plans to advance to a registrational adjuvant study, which may differ from TYRA's expectations; the ability to obtain regulatory approval for dabogratinib; and the other risks and uncertainties described under the heading "Risk Factors" in TYRA's Annual Report on Form 10-K and in subsequent filings with the Securities and Exchange Commission.
You should not place undue reliance on these forward-looking statements, which speak only as of the date they are made. TYRA undertakes no obligation to update or revise any forward-looking statements to reflect new information, future events or otherwise, except as required by applicable law.
Contact
Amy Conrad
aconrad@tyra.bio
View original content to download multimedia:https://www.prnewswire.com/news-releases/tyra-biosciences-reports-initial-phase-2-surf302-results-supporting-the-first-potential-oral-innovation-in-lg-ir-nmibc-with-dabogratinib-302872937.html
SOURCE Tyra Biosciences