Lasmiditan hydrochloride is a high-affinity, highly selective 5-HT1F receptor agonist (Ki=2.1 nM), compared with Ki of 1043 nM and 1357 nM at the 5-HT(1B) and 5-HT(1D) receptors, respectively.IC50 value: 2.1 nM (Ki, 5-HT1F); >1000 nM (Ki, 5-HT1B/5-HT1D) [1]Target: 5-HT1F receptorin vitro: In vitro binding studies Lasmiditan showed a K(i) value of 2.21 nM at the 5-HT(1F) receptor, compared with K(i) values of 1043 nM and 1357 nM at the 5-HT(1B) and 5-HT(1D) receptors, respectively, a selectivity ratio greater than 470-fold. Lasmiditan show higher selectivity for the 5-HT(1F) receptor relative to other 5-HT(1) receptor subtypes than the first generation 5-HT(1F) receptor agonist LY334370. Unlike the 5-HT(1B/1D) receptor agonist sumatriptan, lasmiditan did not contract rabbit saphenous vein rings, a surrogate assay for human coronary artery constriction, at concentrations up to 100 μM.in vivo: In two rodent models of migraine, oral administration of lasmiditan potently inhibited markers associated with electrical stimulation of the trigeminal ganglion (dural plasma protein extravasation, and induction of the immediate early gene c-Fos in the trigeminal nucleus caudalis).

[1]. Nelson DL, et al. Preclinical pharmacological profile of the selective 5-HT1F receptor agonist lasmiditan. Cephalalgia. 2010 Oct;30(10):1159-69. [2]. Tfelt-Hansen PC, et al. The 5-HT1F receptor agonist lasmiditan as a potential treatment of migraine attacks: a review of two placebo-controlled phase II trials. J Headache Pain. 2012 Jun;13(4):271-5.