BACKGROUNDJX11502MA is a potent partial agonist of dopamine D2 and D3 receptors, with a preferential binding profile for D3 receptors in vitro, potentially for treating schizophrenia.METHODSA first-in-human, randomized, double-blind, placebo-controlled, single ascending dose clinical trial was designed. The subjects were randomly assigned to receive JX11502MA and placebo capsules with seven ascending dose groups: 0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, 6 mg, and 8 mg. The PK profiles of JX11502MA and its metabolites were evaluated, along with a safety and tolerability assessment.RESULTSConsidering the safety of participants, the dose escalation was halted at 3 mg. Following single-dose administration, JX11502MA exhibited rapid absorption with a median Tmax ranging from 1 to 1.75 h. The terminal half-life of JX11502MA ranged from 73.62 to 276.85 h. The most common treatment-emergent adverse events (TEAEs) for subjects receiving JX11502MA were somnolence (56.3%), dizziness (18.8%), nausea (21.9%), vomiting (18.8%), and hiccups (18.8%).CONCLUSIONSJX11502MA was generally well tolerated at a single dose of 0.25 to 3 mg. The PK profiles and safety characteristics in this study indicated that JX11502MA has the potential to be a favorable treatment option for patients with schizophrenia.TRIAL REGISTRATIONhttps://clinicaltrials.gov (identifier: NCT05233657).