Ingrezza Treatment for Older Adults with Tardive Dyskinesia Safe and Effective Long-Term According to New Study

According to results of a post hoc analysis of the KINECT-3 (NCT02274558) and KINECT-4 (NCT02405091) clinical studies published in the Journal of Clinical Psychiatry, older adults with tardive dyskinesia (TD) treated with once-daily Ingrezza (valbenazine; Neurocrine Biosciences, San Diego, CA) for up to 48 weeks showed significant and sustained improvements in symptoms. Older adults (aged ≥65 years) who take antipsychotics or other dopamine receptor blocking agents have a higher risk of developing TD. These results demonstrate the benefit of long-term treatment with Ingrezza, a vesicular monoamine transporter 2 (VMAT2) inhibitor, for this higher-risk age group.

Post hoc analysis of pooled data from the phase 3 KINECT-3 extension and KINECT-4 studies included 304 participants (55 [18.1%] aged ≥65 years) who received treatment with Ingrezza 40 mg or 80 mg once daily. Researchers assessed safety and efficacy outcomes based on dose level and participant age.

For older adult participants, mean change in Abnormal Involuntary Movement Scale (AIMS) total score increased from -4.5 ± 0.7 at week 8 to -8.8 ± 0.9 at week 48. Additionally, the percentage of older adult participants who achieved response thresholds for each outcome increased over time:

• The response threshold of a ≥30% improvement in AIMS score was met by 58.0%, 88.5%, and 89.3% of older adults at weeks 8, 24, and 48, respectively.
• The response threshold of a ≥50% improvement in AIMS score was met by 40.0%, 65.4%, and 82.1% of older adults at weeks 8, 24, and 48, respectively.
• The response threshold of a Clinical Global Impression of Change–TD (CGI-TD) scores ≤2 (“much improved” or “very much improved”) was met by 33.3%, 88.5%, and 92.9% of older adults at weeks 8, 24, and 48, respectively.
• The response threshold of a Patient Global Impression of Change (PGIC) scores ≤2 (“much improved” or “very much improved”) was met by 43.1%, 84.6%, and 85.7% of participants at weeks 8, 24, and 48, respectively.

In terms of dose level, at week 48:

• AIMS score ≥30% was reached by 95% and 75% of older adults who received Ingrezza 80 mg and 40 mg, respectively.
• CGI-TD scores ≤2 were reached by 95% and 88% of older adults who received Ingrezza 80 mg and 40 mg, respectively.
• PGIC scores ≤2 were reached by 90% and 75% of older adults who received Ingrezza 80 mg and 40 mg, respectively.

The most common treatment-emergent adverse events (TEAEs) among older adults were urinary tract infections and somnolence, both of which occurred in 10.9% of participants aged ≥65 years.