Open-Label Rollover Study for Continuing Valbenazine Administration for the Treatment of Chorea Associated With Huntington Disease

Prior treatment

• Have received gene therapy at any time
• Have received an investigational drug in a clinical study (other than valbenazine) within 30 days before the baseline visit or plan to use such investigational drug (other than valbenazine) during the study
• Have had a blood loss ≥550 mL or donated blood within 30 days before the baseline visit
• Had a medically significant illness within 30 days before baseline, or any history of neuroleptic malignant syndrome

Other illness

• Have an unstable or serious medical or psychiatric illness
• Have a history of substance dependence or substance (drug) or alcohol abuse, within 1 year of screening
• Have a history of severe hepatic impairment or history of protocol specified hematologic abnormalities during the course of the NBI-98854-HD3005 study
• Have a known hypersensitivity to any component of the formulation of valbenazine
• For participants who did not participate in NBI-98854-HD3005: have a history of VMAT2 inhibitor use within 30 days of baseline

Lab values

• Have a known history of long QT syndrome, cardiac tachyarrhythmia, left bundle-branch block, atrioventricular (AV) block, uncontrolled bradyarrhythmia, or heart failure

Other

• Have difficulty swallowing
• Are currently pregnant or breastfeeding
• Have a significant risk of suicidal behavior

• Either #1 or #2 must be met for inclusion eligibility.
• Have participated in Study NBI-98854-HD3005 and
  • Study drug dosing completion of Study NBI-98854-HD3005, as demonstrated by completed study drug dosing through the follow-up visit or early terminated Study NBI-98854-HD3005 for administrative reasons due to COVID-19 (for example, site closure related to COVID-19)
• Did not participate in Study NBI-98854-HD3005 and
  • Have a clinical and genetic diagnosis of Huntington Disease (HD) with chorea
  • Be able to walk, with or without the assistance of a person or device
• Be able to read and understand English and capable of providing consent to study participation or have a legally authorized representative providing consent and the participant providing assent
• Participants of childbearing potential must agree to use contraception consistently while participating in the study until 30 days after last dose of the study treatment