Valbenazine Promising for Tardive Dyskinesia While Opicapone May Provide New Option for Parkinson Disease

The US Food and Drug Administration (FDA)-approved drug valbenazine (Ingrezza, Neurocrine Biosciences) for the treatment of tardive dyskinesia has passed into another important, well-tolerated phase, according to a presentation given at the 2018 World Congress on Parkinson's Disease and Related Disorders in Lyon, France, last month.

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 Abnormal Involuntary Movement scale (AIMS) total scores, Eiry W. Roberts, MD, explained to MD Magazine® in an interview.

Roberts, the chief medical officer at Neurocrine Biosciences, also said that tardive dyskinesia improvements were reported by patients as well as clinician-reported measurements, with a majority of patients (85%) noting they were "much improved" or "very much improved" when they were on the 40 mg or 80 mg doses.

Furthermore, the results indicated that after the 1-year treatment period as part of KINECT 3 or KINECT 4, there was a positive perception of the drug among participants. Roberts added that valbenazine was generally well-tolerated and there were no new safety signals identified in this phase of the study. Adverse effects such as somnolence and anticholinergic effects, balance disorder or falls, headache, akathisia, vomiting, nausea, and arthralgia were reported previously.

“Prior to the FDA approval of [valbenazine] in 2017, there were no approved treatments for tardive dyskinesia, a condition that is often underdiagnosed and has a serious impact on a patient population already burdened by serious psychiatric disorders,” Roberts said. “These data demonstrate the long-term efficacy and safety of [valbenazine] and the value this treatment brings to patients suffering from this serious, and often isolating, movement disorder.”

The effects of opicapone, an investigational treatment for Parkinson disease specifically designed to give patients and physicians a once-daily option for treating the disease, were also presented.

In June 2016, the European Commission allowed opicapone as an adjunct therapy to treat adults with Parkinson disease after examining a 900-patient study. The treatment is used for patients with end-of-dose motor fluctuations who cannot be stabilized on other combinations; however, it is not yet approved for use in the United States or Canada.

Presenters discussed part of the BIPARK study, which determined that of 600 patients with Parkinson disease with motor fluctuations assigned to opicapone or placebo, 50 mg opicapone doses were effective in reducing OFF-time in the subjects and had a favorable result compared to entacapone.

In another BIPARK arm, switching from entacapone to opicapone showed a significant reduction in OFF-time and increased ON-time without dyskinesia in Parkinson disease patients with motor fluctuations. Plus, the researchers reported, opicapone retained its efficacy throughout the 1-year open-label treatment period.