Tasfygo for unresectable FGFR2‑fusion biliary tract cancer after chemotherapy

Post-marketing Observational Study of Tasfygo Tablet 35 mg to Evaluate the Safety of Tasfygo in Patients With Unresectable Biliary Tract Cancer With FGFR2 Fusion Gene Positivity Who Progressed After Chemotherapy

This study will see if Tasfygo is safe for people with unresectable biliary tract cancer who have an FGFR2 fusion and whose disease progressed after chemotherapy.

Quick facts

• Study type: Observational
• Enrollment: 60 (estimated)
• Sex: All
• Sponsor: Eisai Inc. (industry)
• Drugs / interventions: chemotherapy
• Locations: 1 site (Tokyo)
• Trial ID: NCT06793709 on ClinicalTrials.gov

What this trial studies

This post-marketing observational study collects safety information on Tasfygo in patients with unresectable biliary tract cancer harboring FGFR2 fusions who progressed after prior chemotherapy. Participants who are naïve to Tasfygo tablets will be enrolled and followed at the sponsoring site for adverse events, laboratory results, and clinical outcomes as part of routine care. The study does not assign experimental interventions and treatment decisions are made by the treating physician. Data will be aggregated to characterize the real-world safety profile of Tasfygo in this population.

Who should consider this trial

Good fit: Adults with unresectable biliary tract cancer that tests positive for FGFR2 fusion, who progressed after chemotherapy and have not previously taken Tasfygo tablets, are ideal candidates.

Not a fit: Patients without FGFR2 fusions, those who have already taken Tasfygo tablets, or those with resectable disease are unlikely to benefit from joining this observational safety study.

Why it matters

Potential benefit: If successful, the study could confirm Tasfygo's safety profile in this specific patient group and help clinicians use it more confidently after chemotherapy.

How similar studies have performed: Other FGFR2-targeted therapies, including futibatinib (marketed as Tasfygo), have shown clinical activity in FGFR2‑fusion biliary cancers, and post-marketing monitoring is commonly used to better define safety in broader populations.

Eligibility criteria

Inclusion Criteria:

1\. Participants with unresectable biliary tract cancer with FGFR2 fusion gene positivity who are naïve to Tasfygo tablet and progressed after chemotherapy.

Exclusion Criteria:

Not applicable.

Where this trial is running

Tokyo

• #Eisai Trial Site 1 — Tokyo, Japan (RECRUITING)

Study contacts

• Study coordinator: Eisai Inquiry Service

Conditions: Biliary Tract Cancer, Tasfygo, FGFR2 fusion, Cancer