A randomized, double-blind, placebo controlled, phase 1 study of the safety, tolerability, pharmacokinetics, and pharmacodynamics of LB-102, a selective dopamine D 2/3 /5-HT 7 inhibitor.

LB-102 is an N-methylated analogue of amisulpride under development to treat schizophrenia. LB-102 was evaluated in a Phase 1, double-blind, placebo-controlled, clinical study to evaluate safety and pharmacokinetics. This was a first-in-human study examining single and multiple doses of LB-102 administered orally in 64 healthy volunteers. Dosing in the single ascending dose (SAD) portion of the study was initially planned to be 50, 100, 200, and 400 mg, with doses in the multiple ascending dose (MAD) portion to be determined based on observations in the SAD portion. As a result of two cases of EPS (acute dystonia) at 200 mg in the MAD portion of the study, dosing of that arm was discontinued and doses for the remaining cohort were decreased to 150 mg/day. Dose escalation was guided by safety and plasma concentrations of LB-102 compared to a translational model. LB-102 was generally safe and well-tolerated, and clinical lab values were unremarkable at all doses, save for prolactin which was transiently elevated in the majority of subjects treated with LB-102; there were no clinical observations associated with the increases in prolactin elevation. There was evidence of transient QT interval prolongation at the 200 mg dose, none of which resulted in clinical observation or triggered stopping criteria. There were four instances of EPS (acute dystonia), typically associated with dopamine receptor occupancy in excess of 80%, one at 100 mg QD, one at 75 mg BID, and two at 100 mg BID. A phase 2 clinical study of LB-102 in schizophrenia patients with PANSS as primary endpoint is being planned.