Imetelstat

**Semantic type:** Nucleic Acid, Nucleoside, or Nucleotide|Pharmacologic Substance

**Definition:** A synthetic lipid-conjugated, 13-mer oligonucleotide N3'-P5'-thio-phosphoramidate with potential antineoplastic activity. Complementary to the template region of telomerase (hTR) RNA, imetelstat acts as a competitive enzyme inhibitor that binds and blocks the active site of the enzyme (a telomerase template antagonist), a mechanism of action which differs from that for the antisense oligonucleotide-mediated inhibition of telomerase activity through telomerase mRNA binding. Inhibition of telomerase activity in tumor cells by imetelstat results in telomere shortening, which leads to cell cycle arrest or apoptosis.

**Synonyms:** - DNA, d(3'-amino-3'-deoxy-P-thio)(T-A-G-G-G-T-T-A-G-A-C-A-A), 5'-[O-[2-hydroxy-3- [(1-oxohexadecyl)amino]propyl] hydrogen phosphorothioate] - GRN 163L - GRN 163L - GRN-163L - IMETELSTAT