Apitolisib (GDC-0980)

Administered via p.o.

PC3 and MCF7.1

GDC-0980 is currently in Phase II clinical trials in patients with recurrent or persistent endometrial carcinoma.

GDC-0980 (RG7422) is a potent, selective inhibitor of PI3Kalpha, PI3Kbeta, PI3Kdelta and PI3Kgamma with IC50 of 5 nM, 27 nM, 7 nM, and 14 nM, and also a mTOR inhibitor with Ki of 17 nM.

GDC-0980 (RG7422) is a potent, selective, and orally available inhibitor of PI3Kalpha, beta, delta, gamma and mTOR.

5 nM, 5 nM, 5 nM, 5 nM, 5 nM, 5 nM

In both PC-3 and MCF-7 neo/HER2 xenograft models, GDC-0980 at a dose of 1 mg/kg, exhibits significant antitumor activity by causing tumor growth delay. Furthermore, GDC-0980 results in tumor stasis or regressions at the maximum tolerated dose of 7.5 mg/kg. [1] In mice, intravenous GDC-0980 administration at 1 mg/kg leads to low clearance (Clp: 9.2 mL/min/kg, Vss: 1.7 L/kg). While, oral administration at 5 mg/kg in 80% PEG400 and at 50 mg/kg as a crystalline suspension in 0.5% methylcellulose/0.2% Tween-80 also results in favorable pharmacokinetic parameters. [1]

Enzymatic activity, Enzymatic activity of the Class I PI3K isoforms is measured using a fluorescence polarization assay that monitors formation of the product 3, 4, 5-inositoltriphosphate molecule as it competes with fluorescently labeled PIP3 for binding to the GRP-1 pleckstrin homology domain protein. An increase in phosphatidyl inositide-3-phosphate product results in a decrease in fluorescence polarization signal as the labeled fluorophore is displaced from the GRP-1 protein binding site. Class I PI3K isoforms are expressed and purified as heterodimeric recombinant proteins. PI3K isoforms are assayed under initial rate conditions in the presence of 10 mM Tris (pH 7.5), 25 uM ATP, 9.75 uM PIP2, 5% glycerol, 4 mM MgCl2, 50 mM NaCl, 0.05% (v/v) Chaps, 1 mM dithiothreitol, 2% (v/v) DMSO at the following concentrations for each isoform: PI3Kalpha, beta at 60 ng/mL, PI3Kgamma at 8 ng/mL, PI3Kdelta at 45 ng/mL. After assay for 30 minutes at 25C, reactions are terminated with a final concentration of 9 mM EDTA, 4.5 nM TAMRA-PIP3, and 4.2 ug/mL GRP-1 detector protein before reading fluorescence polarization on an Envision plate reader. IC50s are calculated from the fit of the dose response curves to a 4-parameter equation.Human recombinant mTOR(1360 2549) is expressed and purified from insect cells and assayed using a Lanthascreen fluorescence resonance energy transfer format in which phosphorylation of recombinant green fluorescent protein (GFP)-4-EBP1 is detected using a terbium-labeled antibody to phospho-threonine 37/46 of 4-EBP1. Reactions are initiated with ATP and conducted in the presence of 50 mM Hepes (pH 7.5), 0.25 nM mTOR, 400 nM GFP-4E-BP1, 8 uM ATP, 0.01% (v/v) Tween 20, 10 mM MnCl2, 1 mM EGTA, 1 mM dithiothreitol, and 1% (v/v) DMSO. Assays are conducted under initial rate conditions at room temperature for 30 minutes before terminating the reaction and detecting product in the presence of 2 nM Tb-anti-p4E-BP1 antibody and 10 mM EDTA. Dose response curves are fit to an equation for competitive tight-binding inhibition and apparent Ki' s are calculated using the determined Km for ATP of 6.1 uM.

498, 6

Data independently produced by Dr. Zhang, of Tianjin Medical University, , GDC-0980 (RG7422)purchased from Selleck, After starved in serum-free medium for 24h, A549 cells incubated with the indicated concentrations of GDC-0980 for 3h, followed by 20-minute stimolation of 100ng/ml EGF.

2 years -20CPowder, 2 weeks4Cin DMSO, 2 months-80Cin DMSO