KINECT 4 Trial: Valbenazine Effective in Reducing Tardive Dyskinesia Movements

Long-term treatment with valbenazine improved tardive dyskinesia symptoms over 48 weeks.

Eiry W. Roberts, MD

The long-term use of valbenazine (Ingrezza) proved to be safe and efficacious in reducing abnormal movement for patients with tardive dyskinesia, according to 2 posters presented at the 2018 International Congress of Parkinson's Disease and Movement Disorders (MDS) in Hong Kong.

The team from Neurocrine Biosciences examined the long-term effects of valbenazine on tardive dyskinesia in the KINECT 4 study. They presented their findings stratified both by body region and as well as by changes on the Abnormal Voluntary Movement Scale (AIMS) and the Patient Global Impression of Change (PGIC) scale.

Data from KINECT 4, a long-term study of valbenazine, showed improvements in patients taking 40 mg and 80 mg doses based on changes from baseline to week 48 on the AIMS scale, Eiry W. Roberts, MD, explained to MD Magazine® in an interview last month.

The body regions which had the most participants with a baseline score of ≥3 were lips (n = 59) and tongue (n = 56), as well as jaw (n = 48), upper extremities (n = 48), and face (n = 38). Baseline data was also available for lower extremities in 27 patients and trunk in 26 patients.

The researchers evaluated the patients to see who had shifted to a score of ≤2 (mild to moderate symptoms) after 48 weeks. For lips, jaw, upper extremities, and lower extremities, that rate reached 100% for both 40 mg and 80 mg doses.

The rates of patients shifting to ≤2 score for the remaining body regions varied by dose (40 mg and 80 mg, respectively): face (100%, 97%), tongue (100%, 98%), trunk (88%, 89%).

Trial participants received 48 weeks of open-label valbenazine followed by a 4-week drug-free washout period.

After the full 52 weeks, shift rates decreased across all regions with doses at 40 mg and 80 mg, respectively, the researchers reported: face (56%, 59%), lips (33%, 60%), jaw (50%, 55%), tongue (27%, 44%), upper extremities (63%, 50%), lower extremities (20%, 64%), trunk (50%, 56%). Investigators said the effects of the washout period suggested that patients may require ongoing treatment to maintain improvements in their tardive dyskinesia symptoms.

“Tardive dyskinesia is most commonly associated with noticeable symptoms in the face, but this may not be the reality for all patients,” Roberts, the chief medical officer at Neurocrine Biosciences told MD Magazine. “These data further highlight that symptoms manifest differently throughout the body for patients suffering from tardive dyskinesia, with Ingrezza demonstrating effectiveness regardless of where symptoms are most prominent.”

The second poster discussed the efficacy of valbenazine on tardive dyskinesia patients in terms of the AIMS score and the PGIC ranges. Of the 167 patients enrolled in the study, data was available from 103 patients after 48 weeks.

The clinician-rated tardive dyskinesia improvements were boosted in all dose groups, while the AIMS scale reached -7.2 in 86.4% of the patients surveyed. The average PGIC scores after 48 weeks showed patient-rated global improvements in all dose groups as well, the study authors reported.

In the long-term KINECT 4 study, more than 88% of patients in each valbenazine dose group (40 mg/day or 80 mg/day) had PGIC scores indicating ‘much improved’ or ‘very much improved’ at 48 weeks of treatment,” Roberts said. “This suggests that patients remain satisfied with and continue to gain benefit from Ingrezza after more prolonged treatment.”

The first poster was titled “Effects of Long-Term Valbenazine on Tardive Dyskinesia by Body Region: Shift Analyses of KINECT 4 Study Results” and the second was called “Assessing the Effectiveness of Valbenazine in the Treatment of Tardive Dyskinesia as Determined by the AIMS and PGIC: Results from the KINECT 4 Trial.”