WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 206842

CAS#: 1628256-23-4

Description: G1T38 is an oral, potent and selective CDK4/6 inhibitor for the treatment of Rb competent tumors. Biochemical profiling demonstrates G1T38 is a competitive, nanomolar inhibitor of CDK4/6 with highly selectivity for CDK4-cyclin D1 and CDK6-cyclin D3. G1T38 exhibits a low EC50 (<100 nM) in Rb competent cell lines compared to >3 μM in Rb null cells. In vivo, daily oral treatment with G1T38 causes significant, durable growth inhibition of tumors in a HER2/neu GEMM and in MCF7 xenograft breast cancer models.

Price and Availability




G1T38 is not in stock, may be available through custom synthesis. For cost-effective reason, minimum 1 gram order is requested. The product will be characterized by NMR, HPLC and MS analysis. Purity (HPLC) is usually >98%. CoA, QC data, MSDS will be provided when product is successfully made. The estimated lead time is 2-3 months. Please send email to sales@medkoo.com to inquire quote.

Chemical Structure


Theoretical Analysis

MedKoo Cat#: 206842
Name: G1T38
CAS#: 1628256-23-4
Chemical Formula: C26H34N8O
Exact Mass: 474.2856
Molecular Weight: 474.613
Elemental Analysis: C, 65.80; H, 7.22; N, 23.61; O, 3.37

Synonym: G1T38; G1T-38; G1T 38; G1-T38; G1 T-38; G1 T38;

IUPAC/Chemical Name: 2'-((5-(4-isopropylpiperazin-1-yl)pyridin-2-yl)amino)-7',8'-dihydro-6'H-spiro[cyclohexane-1,9'-pyrazino[1',2':1,5]pyrrolo[2,3-d]pyrimidin]-6'-one


InChi Code: InChI=1S/C26H34N8O/c1-18(2)32-10-12-33(13-11-32)20-6-7-22(27-16-20)30-25-28-15-19-14-21-24(35)29-17-26(8-4-3-5-9-26)34(21)23(19)31-25/h6-7,14-16,18H,3-5,8-13,17H2,1-2H3,(H,29,35)(H,27,28,30,31)


Technical Data

Solid powder

>98% (or refer to the Certificate of Analysis)

Shipping Condition:
Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition:
Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Soluble in DMSO

Shelf Life:
>2 years if stored properly

Drug Formulation:
This drug may be formulated in DMSO

Stock Solution Storage:
0 - 4 C for short term (days to weeks), or -20 C for long term (months).

Harmonized System Code:

Additional Information

Inhibition of the p16INK4a/cyclin D/CDK4/6/RB pathway is an effective therapeutic strategy for the treatment of estrogen receptor positive (ER+) breast cancer.


1: Bisi JE, Sorrentino JA, Jordan JL, Darr DD, Roberts PJ, Tavares FX, Strum JC.
Preclinical development of G1T38: A novel, potent and selective inhibitor of
cyclin dependent kinases 4/6 for use as an oral antineoplastic in patients with
CDK4/6 sensitive tumors. Oncotarget. 2017 Mar 15. doi: 10.18632/oncotarget.16216.
[Epub ahead of print] PubMed PMID: 28418845.

2: Stice JP, Wardell SE, Norris JD, Yllanes AP, Alley HM, Haney VO, White HS,
Safi R, Winter PS, Cocce KJ, Kishton RJ, Lawrence SA, Strum JC, McDonnell DP.
CDK4/6 Therapeutic Intervention and Viable Alternative to Taxanes in CRPC. Mol
Cancer Res. 2017 Jun;15(6):660-669. doi: 10.1158/1541-7786.MCR-17-0028. Epub 2017
Feb 16. PubMed PMID: 28209757.