Sixty milligrams once daily: that is the dose Tyra Biosciences selected from SURF302 after the Phase 2 study returned its first results on September 9, and the choice carries real weight for a company trying to build an oral alternative to intravesical instillation in FGFR3-altered low-grade intermediate-risk non-muscle invasive bladder cancer. The trial had enrolled 44 participants as of the August 31 data cutoff, against a planned maximum of 90, meaning the dataset is still maturing, but Tyra read enough signal to call 60 mg the dose it will carry forward.
The announcement frames SURF302 as clinical proof of concept for selective oral FGFR3 inhibition. That framing matters because dabogratinib’s earlier work, the Phase 1/2 SURF301 study, focused on advanced metastatic urothelial carcinoma, a far sicker population. Moving into low-grade intermediate-risk NMIBC is a different strategic bet: these patients typically face repeated cystoscopies and intravesical treatments over years, not months, so the bar for a daily pill is tolerability as much as efficacy. A dose-selection read at 44 patients does not resolve that question, but it at least narrows the range before enrollment closes.
The competitive context is not simple. Erdafitinib (Balversa) holds FDA approval for FGFR-altered bladder cancer in a more advanced setting, and approved options in the NMIBC space remain limited, particularly for this lower-risk, non-muscle-invasive slice of the disease. Dabogratinib’s selectivity for FGFR3 over other FGFR family members is the differentiating design choice Tyra has emphasized across both trials, with the hypothesis that a tighter selectivity profile reduces off-target toxicity enough to make chronic oral dosing practical for patients who are not yet facing metastatic disease.
With enrollment still below half the target population, the number to watch is what the complete 90-patient cohort shows on endoscopic response: that readout will determine whether 60 mg once daily holds up as a registration-enabling dose or whether SURF302 becomes a learning study for a third trial.
Source link: https://www.sec.gov/Archives/edgar/data/1863127/000119312526385886/d167841d8k.htm
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
