Crizotinib

PF-2341066 displays similar potency against c-Met phosphorylation in mIMCD3 mouse or MDCK canine epithelial cells with IC50 of 5 nM and 20 nM, respectivly. PF-2341066 shows improved or similar activity against NIH3T3 cells engineered to express c-Met ATP-binding site mutants V1092I or H1094R or the P-loop mutant M1250T with IC50 of 19 nM, 2 nM and 15 nM, respectively, compared with NIH3T3 cells expressing wild-type receptor with IC50 of 13 nM. In contrast, a marked shift in potency of PF-2341066 is observed against cells engineered to express c-Met activation loop mutants Y1230C and Y1235D with IC50 of 127 nM and 92 nM, respectively, compared with wild-type receptor. PF-2341066 also potently prevents the phosphorylation of c-Met in NCI-H69 and HOP92 cells, with IC50 of 13 nM and 16 nM, respectively, which express the endogenous c-Met variants R988C and T1010I, respectively. PF-2341066 is >1,000-fold selective for the VEGFR2 and PDGFRβ RTKs, >250-fold selective for IRK and Lck, and ∼40- to 60-fold selective for Tie2, TrkA, and TrkB, all compared with c-Met. PF-2341066 is 20- to 30-fold selective for RON and Axl RTKs. In contrast, PF-2341066 shows a near-equivalent IC50 of 24 nM against the nucleophosmin (NPM)-anaplastic lymphoma kinase (ALK) oncogenic fusion variant of the ALK RTK expressed by the KARPAS299 human anaplastic large cell lymphoma (ALCL) cell line. PF-2341066 inhibits c-Met–dependent neoplastic phenotypes of cancer cells and angiogenic phenotypes of endothelial cells. PF-2341066 suppresses human GTL-16 gastric carcinoma cell growth with IC50 of 9.7 nM. PF-2341066 induces apoptosis in GTL-16 cells with IC50 of 8.4 nM. PF-2341066 inhibits HGF-stimulated human NCI-H441 lung carcinoma cell migration and invasion with IC50 of 11 nM and 6.1 nM, respectively. PF-2341066 inhibits MDCK cell scattering with IC50 of 16 nM. PF-2341066 prevents HGF-stimulated c-Met phosphorylation, cell survival, and Matrigel invasion with IC50 of 11 nM, 14 nM and 35 nM, respectively. In addition, PF-2341066 prevents serum-stimulated HMVEC branching tubulogenesis (formation of vascular tubes) in fibrin gels. ^[1] PF-2341066 also potently inhibits NPM-ALK phosphorylation in Karpas299 or SU-DHL-1 ALCL cells with an IC50 of 24 nM. PF-2341066 potently prevents cell proliferation, which is associated with G(1)-S-phase cell cycle arrest and induction of apoptosis in ALK-positive ALCL cells with IC50 of 30 nM, but not ALK-negative lymphoma cells. ^[2] Besides, PF-2341066 prevents osteosarcoma behavior associated with primary tumor growth (i.e., proliferation and survival) as well as metastasis (eg, invasion and clonogenicity). ^[3]

Cells including GTL-16 gastric carcinoma cells and T47D breast carcinoma cells are seeded in 96-well plates in media supplemented with 10% fetal bovine serum (FBS) and transferred to serum-free media [with 0.04% bovine serum albumin (BSA)] after 24 hours. In experiments investigating ligand-dependent RTK phosphorylation, corresponding growth factors are added for up to 20 minutes. After incubation of cells with PF-2341066 for 1 hour and/or appropriate ligands for the designated times, cells are washed once with HBSS supplemented with 1 mM Na₃VO₄, and protein lysates are generated from cells. Subsequently, phosphorylation of selected protein kinases is assessed by a sandwich ELISA method using specific capture antibodies used to coat 96-well plates and a detection antibody specific for phosphorylated tyrosine residues. Antibody-coated plates are (a) incubated in the presence of protein lysates at 4 °C overnight; (b) washed seven times in 1% Tween 20 in PBS; (c) incubated in a horseradish peroxidase–conjugated anti–total-phosphotyrosine (PY-20) antibody (1:500) for 30 min; (d) washed seven times again; (e) incubated in 3,3^′,5,5^′-tetramethyl benzidine peroxidase substrate to initiate a colorimetric reaction that is stopped by adding 0.09 N H₂SO₄; and (f) measured for absorbance in 450 nm using a spectrophotometer.

In the GTL-16 model, PF-2341066 reveals the ability to cause marked regression of large established tumors (>600 mm³) in both the 50 mg/kg/day and 75 mg/kg/day treatment cohorts, with a 60% decrease in mean tumor volume over the 43-day administration schedule. In an another study, PF-2341066 displays the ability to completely inhibits GTL-16 tumor growth for >3 months, with only 1 of 12 mice exhibiting a significant increase in tumor growth over the 3-month treatment schedule at 50 mg/kg/day. In the NCI-H441 NSCLC model, a 43% decrease in mean tumor volume is observed at 50 mg/kg/day during the 38-day PF-2341066 administration cycle. In the Caki-1 RCC model, a 53% decrease in mean tumor volume is observed to be associated with decreased volume of each tumor by at least 30% at 50 mg/kg/day during the 33-day PF-2341066 administration cycle. PF-2341066 also reveals near-complete prevention of the growth of established tumors at 50 mg/kg/day in the U87MG glioblastoma or PC-3 prostate carcinoma xenograft models, with 97% or 84% inhibition on the final study day, respectively. In contrast, PF-2341066 p.o. given at 50 mg/kg/day does not significantly inhibit tumor growth in the MDA-MB-231 breast carcinoma model, or the DLD-1 colon carcinoma model. A significant dose-dependent reduction of CD31–positive endothelial cells is observed at 12.5 mg/kg/day, 25 mg/kg/day, and 50 mg/kg/day in GTL-16 tumors, indicating that inhibition of MVD shows a dose-dependent correlation to antitumor efficacy. PF-2341066 displays a significant dose-dependent reduction of human VEGFA and IL-8 plasma levels in both the GTL-16 and U87MG models. Marked inhibition of phosphorylated c-Met, Akt, Erk, PLCλ1, and STAT5 levels is observed in GTL-16 tumors following p.o. administration of PF-2341066.^[1] P.o. administration of PF-2341066 to severe combined immunodeficient-Beige mice bearing Karpas299 ALCL tumor xenografts leads to dose-dependent antitumor efficacy with complete regression of all tumors at the 100 mg/kg/d dose within 15 days of initial compound administration. In addition, inhibition of key NPM-ALK signaling mediators, including phospholipase C-gamma, signal transducers and activators of transcription 3, extracellular signal-regulated kinases, and Akt by PF-2341066 are observed at concentrations or dose levels, which correlated with inhibition of NPM-ALK phosphorylation and function.^[2] PF-2341066 prevents osteosarcoma behavior associated with primary tumor growth (eg, proliferation and survival) as well as metastasis (eg, invasion and clonogenicity). In nude mice treated with PF-2341066 via oral gavage, the growth and associated osteolysis and extracortical bone matrix formation of osteosarcoma xenografts are prevented by PF-2341066.^[3] Treatment of c-MET-amplified GTL-16 xenografts with 50 mg/kg PF-2341066 elicits tumor regression that is associated with a slow reduction in ¹⁸F-FDG uptake and decreases expression of the glucose transporter 1, GLUT-1.^[4]