| Description: |
MK-3207 is a potent and orally bioavailable CGRP receptor antagonist (IC50= 0.12 nM; Ki value= 0.024 nM); highly selective versus human AM1, AM2, CTR, and AMY3.
In common with other CGRP receptor antagonists, MK-3207 displays lower affinity for human CGRP receptors from other species, including canine and rodent.
in vitro: MK-3207 is a potent antagonist of the human and rhesus monkey CGRP receptors (K(i) = 0.024 nM).
in vivo: MK-3207 produced a concentration-dependent inhibition of dermal vasodilation, with plasma concentrations of 0.8 and 7 nM required to block 50 and 90% of the blood flow increase, respectively. The tritiated analog [3H]MK-3207 was used to study the binding characteristics on the human CGRP receptor. [3H]MK-3207 displayed reversible and saturable binding (K(D) = 0.06 nM), and the off-rate was determined to be 0.012 min(-1), with a t(1/2) value of 59 min. After the first interim analysis, the two lowest MK-3207 doses (2.5, 5?mg) were identified as showing insufficient efficacy. Per the pre-specified adaptive design decision rule, only the 2.5-mg group was discontinued and the five highest doses (5, 10, 20, 50, 100?mg) were continued into the second stage. |
