Molecule

Description

Cancer

Description

PF-562271 is a potent, ATP-competitive, reversible inhibitor of FAK and Pyk2 with IC50 of 1.5 nM and 14 nM, respectively.

Targets

IC₅₀

In Vitro

PF-562271 shows the selective inhibitory effects on FAK and Pyk2 tyrosine kinase activity with IC50 of 1.5 nM and 14 nM, respectively. And in cell-based assays, the IC50 of PF-562271 is shown to be 5 nM for FAK, which is more selective compared to other kinase targets. ^[1] In 2 dimensional (2D) cultures, PF-562271 results in a dose-dependent cell proliferation inhibition in FAK WT, FAK?/? and FAK kinase-deficient (KD) cells with IC50 of 3.3 μM, 2.08 μM and 2.01 μM, respectively. ^[2]

In Vivo

In several human s.c. xenograft models, PF-562271 exhibits dose-dependent tumor growth inhibition, and produces maximum tumor inhibition for PC-3M, BT474, BxPc3, and LoVo ranging from 78% to 94% inhibition at doses of 25 to 50 mg/kg twice daily, without weight loss, morbidity, or death. ^[1] PF-562271 (25 mg/kg by p.o.) leads to a significant decrease in tumor progression in both subcutaneous and bone metastasis PC3M-luc-C6 xenograft models. ^[3] In a Huh7.5 hepatocellular carcinoma xenograft model, combination therapy of sunitinib and PF-562271 targets angiogenesis and tumor aggressiveness, and produces more significant anti-tumor effect than single agent by blocking tumor growth and impacting the ability of the tumor to recover upon withdrawal of the therapy. ^[4]

Clinical Trials

Features

Recombinant kinase assay and enzyme kinetics

Briefly, purified-activated FAK kinase domain (amino acid 410–689) is reacted with 50 μM ATP and 10 μg per well of a random peptide polymer of Glu and Tyr, p(Glu/Tyr), in kinase buffer [50 mM HEPES (pH 7.5), 125 mM NaCl, and 48 mM MgCl₂] for 15 minutes. Phosphorylation of p(Glu/Tyr) is challenged with serially diluted PF-562271 at 1/2-Log concentrations starting at a top concentration of 1 μM. Each concentration is tested in triplicate. Phosphorylation of p(Glu/Tyr) is detected with a general antiphospho-tyrosine (PY20) antibody followed by horseradish peroxidase (HRP)-conjugated goat anti-mouse IgG antibody. HRP substrate is added, and absorbance readings at 450 nm are obtained after addition of stop solution (2 M H₂SO₄). IC50 values are determined using the Hill-Slope Model. Broad kinase selectivity profiling is performed in house and by using the KinaseProfiler Selectivity Screening Service available through UpState Biotechnology.

Cell Lines

Squamous cell carcinoma (SCC)

Concentrations

0 to 1 μM

Incubation Time

72 hours

Methods

Cells are plated for 48 hours before addition of PF-562271. After 3 days cells are fixed by addition of ice cold 25% trichloroacetic acid (TCA) solution prior to staining with Sulforhodamine B (SRB) dye solution. Plates are washed with 1% glacial acetic acid, air-dried and resuspended in 10 mM Tris buffer, pH 10.5 before reading absorbance at 540 nm. Curve fitting and generation of IC50 values is carried out using GraphPad Prism 4 software from six replicates.

Animal Models

PC-3M, BT474, BxPc3, LoVo, U87MG, H125 and H460 cells are injected s.c. into the right flank of athymic female mice .

Formulation

PF-562271 is dissolved in 5% Gelucire.

Doses

≤100 mg/kg

Administration

Administered via p.o.