imetelstat imetelstat imetelstat (development code grn163l) is an experimental anticancer drug. the first telomerase inhibitor to enter clinical trials, as of early 2023, it was in phase 2/3 trials for various cancer types. imetelstatclinical dataother namesgrn163llegal statuslegal status experimental identifiers iupac name n-methoxy-hydroxy-phosphinothioyl]amino]-5-(6-aminopurin-9-yl)tetrahydrofuran-2-yl]methoxy-hydroxy-phosphinothioyl]amino]-5-(4-amino-2-oxo-pyrimidin-1-yl)tetrahydrofuran-2-yl]methoxy-hydroxy-phosphinothioyl]amino]-5-(6-aminopurin-9-yl)tetrahydrofuran-2-yl]methoxy-hydroxy-phosphinothioyl]amino]-5-(2-amino-6-oxo-1h-purin-9-yl)tetrahydrofuran-2-yl]methoxy-hydroxy-phosphinothioyl]amino]-5-(6-aminopurin-9-yl)tetrahydrofuran-2-yl]methoxy-hydroxy-phosphinothioyl]amino]-5-(5-methyl-2,4-dioxo-pyrimidin-1-yl)tetrahydrofuran-2-yl]methoxy-hydroxy-phosphinothioyl]amino]-5-(5-methyl-2,4-dioxo-pyrimidin-1-yl)tetrahydrofuran-2-yl]methoxy-hydroxy-phosphinothioyl]amino]-5-(2-amino-6-oxo-1h-purin-9-yl)tetrahydrofuran-2-yl]methoxy-hydroxy-phosphinothioyl]amino]-5-(2-amino-6-oxo-1h-purin-9-yl)tetrahydrofuran-2-yl]methoxy-hydroxy-phosphinothioyl]amino]-5-(2-amino-6-oxo-1h-purin-9-yl)tetrahydrofuran-2-yl]methoxy-hydroxy-phosphinothioyl]amino]-5-(6-aminopurin-9-yl)tetrahydrofuran-2-yl]methoxy-hydroxy-phosphinothioyl]amino]-5-(5-methyl-2,4-dioxo-pyrimidin-1-yl)tetrahydrofuran-2-yl]methoxy-hydroxy-phosphinothioyl]oxy-2-hydroxy-ethyl]heptadecanamide cas number868169-64-6pubchem cid71587831drugbankdb05036chemspider34983285uniif60ne4xb53chemical and physical dataformulac148h210n68o53p13s13molar mass46103d model (jsmol)interactive image smiles cccccccccccccccc(=o)ncc(cop(=s)(o)oc1(c(o1)n2c=c(c(=o)nc2=o)c)np(=s)(o)oc3(c(o3)n4c=nc5=c(n=cn=c54)n)np(=s)(o)oc6(c(o6)n7c=nc8=c7n=c(nc8=o)n)np(=s)(o)oc9(c(o9)n1c=nc2=c1n=c(nc2=o)n)np(=s)(o)oc1(c(o1)n1c=nc2=c1n=c(nc2=o)n)np(=s)(o)oc1(c(o1)n1c=c(c(=o)nc1=o)c)np(=s)(o)oc1(c(o1)n1c=c(c(=o)nc1=o)c)np(=s)(o)oc1(c(o1)n1c=nc2=c(n=cn=c21)n)np(=s)(o)oc1(c(o1)n1c=nc2=c1n=c(nc2=o)n)np(=s)(o)oc1(c(o1)n1c=nc2=c(n=cn=c21)n)np(=s)(o)oc1(c(o1)n1c=cc(=nc1=o)n)np(=s)(o)oc1(c(o1)n1c=nc2=c(n=cn=c21)n)np(=o)(oc1(c(o1)n1c=nc2=c(n=cn=c21)n)n)s)o inchi inchi=1s/c148h211n68o53p13s13/c1-5-6-7-8-9-10-11-12-13-14-15-16-17-18-97(218)160-34-69(217)38-255-282(242,295)256-51-95-74(25-102(261-95)207-37-68(4)136(221)191-148(207)229)195-274(234,287)249-45-89-78(29-106(264-89)212-61-175-115-124(155)165-56-170-129(115)212)199-277(237,290)252-48-92-81(32-109(267-92)215-64-178-118-132(215)183-143(158)187-139(118)224)202-280(240,293)254-50-94-82(33-110(269-94)216-65-179-119-133(216)184-144(159)188-140(119)225)203-281(241,294)253-49-93-79(30-107(268-93)213-62-176-116-130(213)181-141(156)185-137(116)222)200-278(238,291)246-42-86-72(23-100(260-86)205-35-66(2)134(219)189-146(205)227)193-272(232,285)245-41-85-73(24-101(259-85)206-36-67(3)135(220)190-147(206)228)194-273(233,286)248-44-88-77(28-105(263-88)211-60-174-114-123(154)164-55-169-128(114)211)198-276(236,289)251-47-91-80(31-108(266-91)214-63-177-117-131(214)182-142(157)186-138(117)223)201-279(239,292)250-46-90-76(27-104(265-90)210-59-173-113-122(153)163-54-168-127(113)210)197-275(235,288)244-40-84-71(22-99(258-84)204-20-19-96(150)180-145(204)226)192-271(231,284)247-43-87-75(26-103(262-87)209-58-172-112-121(152)162-53-167-126(112)209)196-270(230,283)243-39-83-70(149)21-98(257-83)208-57-171-111-120(151)161-52-166-125(111)208/h19-20,35-37,52-65,69-95,98-110,217h,5-18,21-34,38-51,149h2,1-4h3,(h,160,218)(h,242,295)(h2,150,180,226)(h2,151,161,166)(h2,152,162,167)(h2,153,163,168)(h2,154,164,169)(h2,155,165,170)(h,189,219,227)(h,190,220,228)(h,191,221,229)(h2,192,231,284)(h2,193,232,285)(h2,194,233,286)(h2,195,234,287)(h2,196,230,283)(h2,197,235,288)(h2,198,236,289)(h2,199,237,290)(h2,200,238,291)(h2,201,239,292)(h2,202,240,293)(h2,203,241,294)(h3,156,181,185,222)(h3,157,182,186,223)(h3,158,183,187,224)(h3,159,184,188,225)/t69?,70-,71-,72-,73-,74-,75-,76-,77-,78-,79-,80-,81-,82-,83+,84+,85+,86+,87+,88+,89+,90+,91+,92+,93+,94+,95+,98+,99+,100+,101+,102+,103+,104+,105+,106+,107+,108+,109+,110+,270?,271?,272?,273?,274?,275?,276?,277?,278?,279?,280?,281?,282?/m0/s1key:lvzyxealrxbljz-isqycpacsa-n chemically, imetelstat is a synthetic conjugate consisting of three parts: grn163, a thio phosphoramide oligonucleotide, and a palmitoyl lipid group. grn163 is the pharmacological component with telomerase inhibition. the palmitic acid moiety is conjugated via a phosphothioate linkage to the backbone of the antisense oligonucleotide. telomere shortening and lower cell viability are observed after inhibition of telomerase activity in vitro. ic50 values ranged from 50 to 200nm for 10 different pancreatic cell lines.