Raw research findings for this medication. Mostly single studies, not curated or confirmed robust.
Lonsurf is an oral chemotherapy combining trifluridine, a nucleoside analogue that is built into DNA and disrupts it, with tipiracil, which blocks thymidine phosphorylase, the enzyme that would otherwise break trifluridine down quickly. It is used for advanced bowel and stomach cancers after other treatments, alone or with bevacizumab.
Trifluridine enters cells partly through the nucleoside transporter SLC29A1, and tipiracil is cleared by the kidneys with the help of SLC22A2 and SLC47A1. The gene studies on this page, from a small number of studies, looked at these transporter genes for how well treatment worked. There is no CPIC or DPWG guideline.
Every published finding on gene variants and Lonsurf. Upload your DNA file to see which of these rows apply to you.
PharmGKB weighs all studies of a variant and rates how strong the evidence is, from 1A (strongest) to 4.
SLC29A1 rs9394992: Level 3. Efficacy: Colorectal Neoplasms. 1.
SLC29A1 rs760370: Level 3. Efficacy: Colorectal Neoplasms. 1.
Studies of how well it worked in people carrying a variant.
Study findings and evidence levels: PharmGKB (CC BY-SA 4.0). Guidelines: CPIC and DPWG, as bundled in PharmCAT. Most studies were done mainly in people of European ancestry.
More drugs from the same category
Not a prescribing recommendation. This page is educational information about pharmacogenomic research and clinical guidelines - it is not medical or dosing advice, and not a prediction of how any medication will work for you. Never start, stop, or change a medication or dose based on it; talk to your doctor or pharmacist, who can order clinical-grade testing if appropriate.
Content updated September 2026.
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