FGFR3 as a Radioligand Therapy Target
FGFR3, fibroblast growth factor receptor 3, is a cell-surface protein (membrane receptor). In Human Protein Atlas immunohistochemistry, FGFR3 staining is highest in testicular cancer (75% of samples positive), head and neck cancer (75% of samples positive) and skin cancer (75% of samples positive). Published literature reports that FGFR3 internalizes after ligand binding, which helps retain a radionuclide inside tumor cells. Clinical status: Clinical-stage (up to phase 3, any modality).
Is FGFR3 a good radioligand therapy target?
Scored against the six criteria that decide whether a protein can become a radioligand therapy:
- ✅ Cell-surface accessibility: Localized to the cell surface, so a radioligand can reach it from circulation.
- ✅ Tumor expression: High IHC staining in testicular cancer, 75% of samples positive.
- ✅ Internalization: Reported to internalize, which favors radionuclide retention.
- ✅ Clinical precedent: Clinical-stage (up to phase 3, any modality)
- ❔ Shedding: Not yet assessed.
- ❔ Normal-tissue dosimetry: Check kidney, liver, bone marrow and salivary expression in the Human Protein Atlas tissue atlas.
FGFR3 expression in cancer
Protein expression of FGFR3 across 20 cancer types from Human Protein Atlas immunohistochemistry. The score is a weighted staining intensity from 0 to 1; "% positive" is the share of patient samples with detectable staining.
| Cancer type | IHC score | Level | % positive |
|---|---|---|---|
| Testicular Cancer | 0.53 | High | 75% |
| Head and Neck Cancer | 0.50 | Medium | 75% |
| Skin Cancer | 0.42 | Medium | 75% |
| Bladder Cancer | 0.33 | Medium | 55% |
| Cervical Cancer | 0.24 | Medium | 55% |
| Lung Cancer | 0.22 | Medium | 42% |
| Liver Cancer | 0.22 | Medium | 42% |
| Neuroendocrine Tumors | 0.22 | Medium | 33% |
| Endometrial Cancer | 0.19 | Low | 50% |
| Glioma | 0.19 | Low | 42% |
| Colorectal Cancer | 0.13 | Low | 40% |
| Ovarian Cancer | 0.12 | Low | 27% |
| Prostate Cancer | 0.09 | Low | 27% |
| Pancreatic Cancer | 0.08 | Low | 17% |
| Breast Cancer | 0.06 | Low | 9% |
Not detected by IHC in: lymphoma, melanoma, kidney cancer, thyroid cancer, gastric cancer.
Is FGFR3 internalized?
Yes. Mechanistic studies showed binding to FGFR3, internalization and lysosomal release of LZU-WZLYFG001.
Sources: PMID 41809890 · PMID 38951140 · PMID 33837264 · PMID 32798495 · PMID 32088326. AI-extracted from abstracts, so verify before citing.
FGFR3 clinical trials
Clinical-stage (up to phase 3, any modality). Nuclens hasn't indexed trials for FGFR3 yet. Search ClinicalTrials.gov for FGFR3 trials.
FGFR3 normal tissue expression
Normal-tissue expression in dose-limiting organs (kidney, liver, bone marrow, salivary glands) drives radioligand dosimetry risk. Nuclens is re-validating its normal-tissue values, so they are not shown here yet. See FGFR3 in the Human Protein Atlas tissue atlas, and read how normal-tissue expression predicts radioligand dosimetry risk.
FGFR3 gene essentiality (DepMap)
CRISPR knockout effect across 1258 cancer cell lines: 0.05 (not essential). Radioligands kill by radiation, not by blocking the target, so essentiality matters less than for inhibitors. A non-essential target can still be an excellent radioligand target.
Related testicular cancer radioligand targets
HER3 (ERBB3) · c-MET (MET) · STEAP2 · KIT · SSTR2 · TMEFF2 · Mesothelin (MSLN) · HER2 (ERBB2)
See all radioligand therapy targets in testicular cancer.
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Subcellular localization: UniProt via Open Targets (CC BY 4.0 / CC0). Tumor immunohistochemistry: Human Protein Atlas (CC BY-SA 4.0). Clinical trials: ClinicalTrials.gov (public domain). Gene essentiality: DepMap (CC BY 4.0). Internalization and shedding: AI-extracted from PubMed abstracts, so verify against the cited papers before relying on them. Nuclens is a first-pass triage layer, not a substitute for wet-lab validation or clinical dosimetry. Derived expression data on this page is shared under CC BY-SA 4.0.