{"entity":{"id":"fgfr3","kind":"term","name":"FGFR3 alterations (bladder cancer)","aka":[],"tldr":"FGFR3 is a growth-receptor gene mutated or fused in about a fifth of advanced bladder cancers and most low-grade early ones. It is the only targetable biomarker in bladder cancer so far.","summary":"FGFR3 is a growth-receptor gene altered by point mutation or fusion in a substantial share of advanced bladder cancers and in most low-grade early ones, and it is so far the only targetable biomarker in this disease. The alterations include the S249C, R248C and Y373C point mutations and the FGFR3-TACC3 fusion, and they define luminal-papillary tumours that tend to be less immune-infiltrated. Erdafitinib is approved for FGFR3-altered disease after immunotherapy on the strength of the THOR trial. Testing is by NGS on tissue or on urine and ctDNA. The term is referenced from the Bladder & urothelial cancer and Urethral cancer entries, from Erdafitinib and THOR, and it sits alongside the FGFR2 target record.","asOf":"2026-09-07","wikipedia":"https://en.wikipedia.org/wiki/Fibroblast_growth_factor_receptor_3","links":[{"label":"ClinicalTrials.gov NCT03390504: THOR","url":"https://clinicaltrials.gov/study/NCT03390504"}],"tags":[],"related":[],"cancers":["urothelial"],"sections":[],"technologies":[],"targets":["fgfr2"],"drugs":["erdafitinib"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":["thor"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"category":"Biomarkers"},"route":"/terms/fgfr3/","neighbours":{"cancer":[{"id":"urothelial","kind":"cancer","name":"Bladder & urothelial cancer","route":"/cancers/urothelial/"},{"id":"urethral","kind":"cancer","name":"Urethral cancer","route":"/cancers/urethral/"},{"id":"urethral-urothelial-carcinoma","kind":"cancer","name":"Urothelial carcinoma of the urethra","route":"/cancers/urethral-urothelial-carcinoma/"}],"target":[{"id":"fgfr2","kind":"target","name":"FGFR2","route":"/targets/fgfr2/"}],"drug":[{"id":"erdafitinib","kind":"drug","name":"Erdafitinib","route":"/drugs/erdafitinib/"}],"trial":[{"id":"thor","kind":"trial","name":"THOR","route":"/trials/thor/"}],"biomarker":[{"id":"fgfr3-alteration","kind":"biomarker","name":"FGFR3 alteration (mutation or fusion)","route":"/biomarkers/fgfr3-alteration/"}]}}