Efficacy of Valbenazine for the Treatment of Trichotillomania in Adults

Eligible subjects will be randomized in a double-blind manner in a 1:1 ratio to once-daily doses of valbenazine or placebo for 12 weeks. After week 12, all subjects will begin the 12-week, open-label portion of the study in which they all get their optimal dose. Follow-up assessments will be conducted at the end of week 26 (2 weeks after the last dose of the study drug). For subjects randomized to active treatment, the starting dose will be valbenazine 40mg, which may be escalated to 80mg to achieve an optimal dose of valbenazine for each subject. Dose escalation will occur at the end of week 2 based on the following criteria: 1) the subject's TTM symptoms are not sufficiently controlled per physician investigator assessment and 2) an evaluation by the physician investigator indicates that the subject is tolerating the study drug at the current dose and would likely be able to tolerate the higher dose level. At week 4, the physician investigator may choose to keep the subject at the higher dose or may reduce to the subject's prior tolerated dose (in subjects who have had dose escalation). If a subject's optimal dose was established as 40mg at week 2, no dose escalation will be allowed at week 4. At any time after week 2, the physician investigator may decrease the dose to the previous dose for any subject who had a dose escalation and who is unable to tolerate a given dose increase. The investigator may reduce the subject's dose only one time. Subjects who are unable to tolerate the starting dose or resumption of the 40mg dose will be discontinued from the study. The subject will continue at the dose reached during the optimization period for the remainder of the 12-week treatment period. To maintain the study blind, subjects randomized to placebo in each weight group will be subjected to the same dose escalation requirements, but will receive only placebo during the treatment period. Following the 12-week, double-blind study, all subjects will be offered the option to receive open-label valbenazine for 12 weeks. In order to protect the blind in the first phase of the trial all subjects will receive 40mg of valbenazine from week 12 to week 14 and then be titrated on the study medication similar to the first phase of the trial from that point forward.