5 research outputs found
Effect of MRLB-11055 on major lymphoid populations in spleen of WT B6 mice.
<p>MRLB-11055 was given for either 3 or 6 days (on), followed up by either a 0 or 4 day holiday (off), for up to 4 cycles. Effects on NK, B and T cells were measured by flow cytometry.</p
Discovery of 1‑[3-(1-Methyl‑1<i>H</i>‑pyrazol-4-yl)-5-oxo‑5<i>H</i>‑benzo[4,5]cyclohepta[1,2‑<i>b</i>]pyridin-7-yl]‑<i>N</i>‑(pyridin-2-ylmethyl)methanesulfonamide (MK-8033): A Specific c‑Met/Ron Dual Kinase Inhibitor with Preferential Affinity for the Activated State of c‑Met
This
report documents the first example of a specific inhibitor
of protein kinases with preferential binding to the activated kinase
conformation: 5<i>H</i>-benzoÂ[4,5]ÂcycloheptaÂ[1,2-<i>b</i>]Âpyridin-5-one <b>11r</b> (MK-8033), a dual c-Met/Ron
inhibitor under investigation as a treatment for cancer. The design
of <b>11r</b> was based on the desire to reduce time-dependent
inhibition of CYP3A4 (TDI) by members of this structural class. A
novel two-step protocol for the synthesis of benzylic sulfonamides
was developed to access <b>11r</b> and analogues. We provide
a rationale for the observed selectivity based on X-ray crystallographic
evidence and discuss selectivity trends with additional examples.
Importantly, <b>11r</b> provides full inhibition of tumor growth
in a c-Met amplified (GTL-16) subcutaneous tumor xenograft model and
may have an advantage over inactive form kinase inhibitors due to
equal potency against a panel of oncogenic activating mutations of
c-Met in contrast to c-Met inhibitors without preferential binding
to the active kinase conformation
Exposure and target engagement of MRLB-11055 in the peripheral blood of C57BL/6 mice stimulated with darbepoetin.
<p>A. Effect of MRLB-11055 on phosphoSTAT5 levels at various times post-dose. B. Calculation of IC50 value for inhibition of phosphoSTAT5. C. PK of 3 doses of MRLB-11055 in mouse blood, with calculated IC50 superimposed (dashed line).</p
Effect of 2 Cycles of Intermittent Dosing (3 days on, 4 days off) of MRLB-11055 on V617F-Luc2 Mice (N = 10).
<p>Effect on A & B. Bioluminescence in spleen C. Hematocrit D. Multiple endpoints at end of study (Day 14).</p
Effect of MRLB-11055 in a Darbepoetin-Induced PV Efficacy Model.
<p>The ability of MRLB-11055 to prevent darbepoetin-induced increases in hematocrit (Hct) and spleen mass (SPL) over 7 days is shown, as is the impact of MRLB-11055 on white blood cells (WBC) and its concentration in blood (PK). Dashed line indicates <i>in vivo</i> IC50 value.</p