Repinotan (BAYX3702) is a highly selective 5-HT1A receptor agonist that has shown neuroprotective effects in animals (attenuating NMDA-induced delayed neuronal death in rats). Repinotan inhibits glutamate induced depolarization. A variety of mechanisms and pathways is thought to be involved in its efficacy, such as activation of the anti-apoptotic phosphatidylinositol 3-kinase (PI-3K) pathway, inhibition of glutamate release, extracellular-regulated kinase (Erk)-stimulated Bcl-2 expression or inhibition of caspase-3 activity, and increased release of the neurite extension factor S-100 beta. Based on results in animal studies, repinotan could be a promising candidate for treating acute ischemic stroke in humans. A phase II clinical trials in patients with acute ischemic stroke was completed in 2009.