Imagabalin
Imagabalin was an investigational drug that acts as a ligand for the α2δ subunit of the voltage-dependent calcium channel, with some selectivity for the α2δ1 subunit over α2δ2. It was under development by Pfizer as a pharmaceutical medication due to its hypothesized anxiolytic, analgesic, hypnotic, and anticonvulsant-like activity. It reached phase-III clinical trials for treatment of generalized anxiety disorder; however, the trials were terminated by the manufacturer. The drug is no longer under development.