MK-3207 HCl

MK-3207 (Hydrochloride) is a potent and orally bioavailable CGRP receptor antagonist with IC50 of 0.12 nM and Ki of 0.024 nM, and is highly selective versus human AM1, AM2, CTR, and AMY3.

Signaling Pathways >> GPCR/G Protein >> CGRP Receptor

Signaling Pathways >> Neuronal Signaling >> CGRP Receptor

Research Areas >> Neurological Disease

IC50: 0.12 nM (CGRP receptor)

MK-3207 displays a similar affinity (Ki) for the rhesus monkey receptor (0.024±0.001 nM; n=14) as for human, but it displays >400-fold lower affinity for the canine and rat receptors, with values of 10 nM and 10±1.2 nM, respectively. MK-3207 is highly selective versus the human AM1 (CLR/RAMP2) and AM2 (CLR/RAMP3) receptors, with Ki values of 16,500 nM and 156±17 nM, respectively. MK-3207 maintains a high degree of selectivity versus human CTR, with a Ki value of 1.9±0.58 μM. MK-3207 also displays good selectivity versus the AMY3 (CTR/RAMP3) receptor, with a Ki value of 128±25 nM, but it is less selective versus the AMY1 (CTR/RAMP1) receptor, with a Ki value of 0.75±0.13 nM. MK-3207 potently blocks human α-CGRP-stimulated cAMP responses in human CGRP receptor-expressing HEK293 cells, with an IC50 value of 0.12±0.02 nM. MK-3207 displays significantly lower potency for the rat CGRP receptor, with a pIC50=7.31±0.09[1].

MK-3207 is CNS-penetrant and therefore significantly engaging central receptors. After an oral dose of 10 mg/kg MK-3207, the CSF/plasma ratio is 2 to 3%[1].

Amylin binding assays are conducted by combining MK-3207 and 40 pM 125I-rat amylin, followed by 25 μg of CTR/RAMP1 or 25 μg of CTR/RAMP3 membranes and incubated for 3 h at room temperature in binding buffer (10 mM HEPES, 5 mM MgCl2, and 0.2% bovine serum albumin) in a total volume of 1 mL. Calcitonin binding assays are with 25 μg of CTR membranes and 30 pM 125I-human calcitonin as the radioligand. Incubations are terminated by filtration through GF/B 96-well filter plates that has been blocked with 0.5% polyethylenimine. Data are analyzed using Prism, and the Ki value is determined using the equation Ki=IC50/1 + ([ligand]/KD). The KD value for each receptor is determined by saturation binding experiments.

A customized flexible silicone catheter is freely suspended in the cisterna magna, anchored firmly on both sides of the atlanto-occipital membrane, and tunneled subcutaneously to the midscapular region where it is fed into a surgically implanted port body. CSF is accessed by aseptically inserting a needle through the skin and membrane covering the port into the reservoir of the port body; blood samples are collected by peripheral venipuncture. After oral administration of MK-3207 at 10 mg/kg (0.5% methylcellulose, with an adjusted pH appr 3) to cisterna magna catheter and port-implanted rhesus monkeys, CSF and plasma samples are collected at 0.5, 1, 2, 4, 8, and 24 h and analyzed for compound levels.

[1]. Salvatore CA, et al. Pharmacological properties of MK-3207, a potent and orally active calcitonin gene-related peptide receptor antagonist. J Pharmacol Exp Ther. 2010 Apr;333(1):152-60.

Olcegepant | BMS-927711 | MK-0974 | Calcitonin Gene Related Peptide Fragment 8-37 human | MK-3207 | Rat CGRP-(8-37) | Adrenomedullin (22-52) (human) | Ubrogepant | β-CGRP (human)