Basmisanil (; developmental codes RG-1662 and RO5186582) is a highly selective inverse agonist/negative allosteric modulator of ñ<sub>5</sub> subunit-containing GABA<sub>A</sub> receptors which is under development by Roche for the treatment of cognitive impairment associated with Down syndrome. As of June 2016, it is no longer studied for this purpose. It underwent a clinical trial for cognitive impairment in patients with schizophrenia.