Study to Evaluate the Efficacy, Safety, and Tolerability of Valbenazine as an Adjunctive Treatment for Schizophrenia

This primary objective for this study is to evaluate the effect of adjunctive valbenazine versus placebo on symptoms of schizophrenia in participants who have inadequate response to antipsychotic treatment.

Key Inclusion Criteria:Medically confirmed diagnosis of schizophreniaParticipant is receiving a stable regimen of background antipsychotic medicationPlasma levels for at least 1 of the participant's antipsychotic medications must be detectable by an available assayParticipant is an outpatient with stable symptomatologyParticipant must have an adult informant (for example, a family member, relative, partner, social worker, caseworker, residential facility staff, or nurse)Key Exclusion Criteria:Has a history of treatment resistant schizophreniaHave a clinically significant unstable medical condition in the judgement of the investigator or any laboratory value outside the normal range that is considered by the investigator to be clinically significant at the screening visitPrior (within 6 months of Screening) or concomitant use of any vesicular monoamine transporter 2 (VMAT2) inhibitor (that is, valbenazine, reserpine, tetrabenazine, deutetrabenazine); or a history of intolerance to VMAT2 inhibitors