Tavapadon (0.1 mg/kg; s.c.) has the mean maximal unbound plasma concentration of 8 nM and achieves 3 hours after compound administration in captive-bred macaques. Tavapadon (0.02 and 0.04 mg/kg; s.c.) at the 0.04 mg/kg test dose increases locomotor activity, whereas the 0.02 mg/kg dose has little or no effect. Tavapadon (0.04 mg/kg, s.c.) also improves parkinsonian disability scores with the maximal improvement observed at 110 min after drug administration. Higher doses of Tavapadon (0.1 and 0.15 mg/kg; s.c.) cause statistically significant improvement relative to vehicle in locomotor activity [1].