Technetium (99mTc) etarfolatide

Technetium (99mTc) etarfolatide is an investigational non-invasive, folate receptor-targeting companion imaging agent that is being developed by Endocyte.[1] Etarfolatide consists of a small molecule targeting the folate receptor and an imaging agent, which is based on technetium-99m. This companion imaging agent identifies cells expressing the folate receptor, including cancer and inflammatory cells.[2]

Technetium (99mTc) etarfolatide
Clinical data
ATC code
Legal status
Legal status
  • Investigational
Identifiers
  • (2R)-2-[(2S)-2-[(2S)-3-[[(4R)-4-[[4-[(2-amino-4-oxo-1H-pteridin-6-yl)methylamino]benzoyl]amino]-4-carboxybutanoyl]amino]-2-azanidylpropanoyl]azanidyl-3-carboxypropanoyl]azanidyl-3-hydroxy-3-oxopropane-1-thiolate oxotechnetium(4+) (99mTc)
CAS Number
PubChem CID
UNII
KEGG
CompTox Dashboard (EPA)
Chemical and physical data
FormulaC29H32N11O12S99mTc
Molar mass855.595 g/mol
3D model (JSmol)
  • C1=CC(=CC=C1C(=O)N[C@H](CCC(=O)NC[C@@H](C(=O)[N-][C@@H](CC(=O)O)C(=O)[N-][C@@H](C[S-])C(=O)O)[NH-])C(=O)O)NCC2=CN=C3C(=N2)C(=O)N=C(N3)N.O=[99Tc+4]

Etarfolatide is currently being investigated together with the corresponding small molecule drug conjugate (SMDC) vintafolide in a Phase 3 study in platinum-resistant ovarian cancer and in a Phase 2b study in non-small cell lung cancer. It identifies patients with metastases that are positive for the folate receptor and therefore more likely to respond to treatment with vintafolide.[1][2] Other folate receptor targeting SMDCs for the treatment of cancer, inflammatory diseases and kidney disease are in preclinical development and will also utilize etarfolatide as companion imaging agent.[3][4]

The European Medicines Agency (EMA) is reviewing the Marketing Authorization Application (MAA) filings for both vintafolide and etarfolatide, for the treatment of patients with folate receptor-positive platinum-resistant ovarian cancer in combination with pegylated liposomal doxorubicin (PLD).[5]

References

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