# FGFR3

Source: https://onco.cc/targets/fgfr3-receptor/  
OnCo record `fgfr3-receptor` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A growth-factor receptor that is mutated or fused in a sizeable minority of bladder cancers. Erdafitinib blocks it and is the first targeted drug approved for urothelial cancer selected by a genomic test.

## Summary

FGFR3 activating mutations and FGFR3::TACC3 fusions drive a subset of urothelial carcinomas, especially the luminal-papillary type, and are also common in non-invasive bladder tumours. Erdafitinib, a pan-FGFR inhibitor, received accelerated US approval in 2019 for FGFR3- or FGFR2-altered advanced urothelial cancer and full approval in 2024 after the THOR trial showed a survival benefit over chemotherapy in patients previously treated with a checkpoint inhibitor. Hyperphosphataemia, from FGFR1 blockade in the kidney, and eye toxicity are the class effects. FGFR3-altered tumours tend to be immunologically cold, which shapes the debate about sequencing targeted therapy and immunotherapy.

## Fields

- Kind: Target
- Last checked: 2026-09-04
- Symbol: FGFR3
- Class: kinase
- Biology: Receptor tyrosine kinase for fibroblast growth factors; activating point mutations (S249C, Y373C) and TACC3 fusions in urothelial carcinoma.
- Where found: Urothelial carcinoma, most often luminal-papillary and non-invasive tumours; Multiple myeloma with t(4;14)

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Fibroblast_growth_factor_receptor_3
- UniProt P22607: FGFR3: https://www.uniprot.org/uniprotkb/P22607/entry

## Connected records

- targets: [FGFR2](https://onco.cc/targets/fgfr2/)
- biomarkers: [FGFR3 alteration (mutation or fusion)](https://onco.cc/biomarkers/fgfr3-alteration/)
- cancers: [Bladder & urothelial cancer](https://onco.cc/cancers/urothelial/), [Muscle-invasive and advanced bladder cancer](https://onco.cc/cancers/muscle-invasive-bladder-cancer/)
- drugs: [Erdafitinib](https://onco.cc/drugs/erdafitinib/)
- trials: [THOR](https://onco.cc/trials/thor/)

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JSON: https://onco.cc/api/v1/entities/fgfr3-receptor.json