Brexpiprazole for the Treatment of Agitation in Alzheimer Dementia: A Randomized Clinical Trial

Importance

Agitation is a prevalent, distressing, and burdensome manifestation of Alzheimer dementia in need of an efficacious, safe, and well-tolerated treatment.

Objective

To confirm the efficacy, safety, and tolerability of brexpiprazole in patients with agitation in Alzheimer dementia.

Design, Setting, and Participants

This randomized clinical trial was a 12-week, double-blind, placebo-controlled, fixed-dose, parallel-arm trial that ran from May 2018 to June 2022 at 123 clinical trial sites in Europe and the United States. Participants included patients with agitation in Alzheimer dementia in a care facility or community-based setting. Stable Alzheimer disease medications were permitted.

Interventions

In this 2-arm trial, patients were randomized to receive oral brexpiprazole or placebo (2:1 ratio) for 12 weeks. Within the brexpiprazole arm, patients were further randomized to receive fixed doses of 2 mg/d or 3 mg/d in a 1:2 ratio.

Main Outcomes and Measures

The primary end point was change in Cohen-Mansfield Agitation Inventory total score (which measures the frequency of 29 agitated behaviors) from baseline to week 12 for brexpiprazole, 2 or 3 mg, vs placebo. Safety was assessed by standard measures, including treatment-emergent adverse events.

Results

A total of 345 patients were randomized to receive brexpiprazole (n = 228) or placebo (n = 117); completion rates were 198 (86.8%) for brexpiprazole and 104 (88.9%) for placebo. Mean (SD) age was 74.0 (7.5) years, and 195 of 345 patients were female (56.5%). Patients receiving brexpiprazole, 2 or 3 mg (n = 225), demonstrated statistically significantly greater improvement than those taking placebo (n = 116) in Cohen-Mansfield Agitation Inventory total score from baseline to week 12 (brexpiprazole baseline, 80.6, mean change, -22.6; placebo baseline, 79.2, mean change, -17.3; least-squares mean difference, -5.32; 95% CI, -8.77 to -1.87; P = .003; Cohen d effect size, 0.35). No treatment-emergent adverse events had an incidence of 5% or more with brexpiprazole and greater incidence than placebo. The proportion of patients who discontinued because of adverse events was 12 of 226 (5.3%) for brexpiprazole and 5 of 116 (4.3%) for placebo.

Conclusions and Relevance

In this study, patients with Alzheimer dementia who took brexpiprazole, 2 or 3 mg, showed a statistically significant improvement vs placebo in agitation over 12 weeks. Brexpiprazole was generally well tolerated over 12 weeks in this vulnerable patient population.

Trial Registration

ClinicalTrials.gov Identifier: NCT03548584.

How Adaptive Trial Designs can Increase Efficiency in Psychiatric Drug Development: A Case Study

This paper uses a recently completed study to illustrate how adaptive trial designs can increase efficiency of psychiatric drug development. The design employed allowed a continuous reassessment of the estimated dose-response such that patients were randomized in a double-blind fashion to one of seven doses of the investigational drug, placebo, or active comparator. The study design also permitted early detection of futility allowing for early study termination. By using the adaptive trial design approach, only 202 patients were needed to make the determination of futility. In contrast, a conventional design would have required enrollment of 450 patients and considerably more time and expense to reach the same conclusion. Adaptive trial designs are important at this time when many pharmaceutical companies are abandoning the development of psychiatric medications because of the inefficiency of conventional approaches.

The use of vinca alkaloids in preparation for splenectomy of corticosteroid refractory chronic immune thrombocytopenic purpura patients

Administration of vinca alkaloids (VA) to chronic corticosteroid refractory immune thrombocytopenia (ITP) patients results in a temporary increase of platelet count. The aim of the study was to evaluate the efficacy of vinca alkaloids in preparing adult corticosteroid refractory chronic ITP patients for splenectomy as well as to compare the costs of this method with costs of applying intravenous immunoglobulins. The study included 12 chronic ITP patients refractory to corticosteroids applied for 3-144 months. The patients were prepared for splenectomy with average 3.0 (from 1 to 4) 2-h intravenous infusions of vinca alkaloids at 7 day intervals. In eight patients, vincristin was used in a total dose of 6 mg (2 mg per infusion), in two patients, vinblastin was used in total dose of 30 mg (10 mg per infusion), and in two patients, vincristin and vinblastin infusions were administered alternatively. In nine of the 12 treated patients (75%) the platelet count increased to > or = 80 x 10(9)/l, which allowed safe splenectomy. Three patients unreactive to VA treatment were prepared for splenectomy with intravenous gammaglobulin infusions. Splenectomy was performed in 12 patients, in eight with laparoscopic method, in four with classic method. No complications during surgical intervention were observed. In none of the VA treated patients was myelosupression or liver or/and kidney dysfunction observed. Splenectomy resulted in normalization of platelet count in all patients after operation and in six of nine patients followed up for 10 months (on the average). Matching of VA costs with treatment efficacy and comparison with similar costs for intravenous immunoglobulin treatment revealed many fold lower costs of the former method.

Efficacy of the novel anxiolytic pregabalin in social anxiety disorder: a placebo-controlled, multicenter study

Pregabalin is a novel compound in development for the treatment of anxiety disorders. The safety and efficacy of pregabalin for the treatment of social anxiety disorder was evaluated in a double-blind, multicenter clinical trial in which 135 patients were randomized to 10 weeks of double-blind treatment with either pregabalin 150 mg/d. pregabalin 600 mg/d, or placebo. The primary efficacy parameter was change from baseline to end point in the Liebowitz Social Anxiety Scale (LSAS) total score. Safety was assessed through clinical and laboratory monitoring, and recording spontaneously reported adverse events. Ninety-four patients (70%) completed the 11-week double-blind treatment phase. LSAS total score was significantly decreased by pregabalin 600 mg/d treatment compared with placebo (P = 0.024, analysis of covariance). Significant differences (P < or = 0.05) between pregabalin 600 mg/d and placebo were seen on several secondary measures including the LSAS subscales of total fear, total avoidance, social fear, and social avoidance, and the Brief Social Phobia Scale fear subscale. Pregabalin 150 mg/d was not significantly better than placebo on any measures. Somnolence and dizziness were the most frequently occurring adverse events among patients receiving pregabalin 600 mg/d. In conclusion, pregabalin 600 mg/d was an effective and well-tolerated treatment of social anxiety disorder.

MRI as a biomarker of disease progression in a therapeutic trial of milameline for AD

OBJECTIVE

To assess the feasibility of using MRI measurements as a surrogate endpoint for disease progression in a therapeutic trial for AD.

METHODS

A total of 362 patients with probable AD from 38 different centers participated in the MRI portion of a 52-week randomized placebo-controlled trial of milameline, a muscarinic receptor agonist. The therapeutic trial itself was not completed due to projected lack of efficacy on interim analysis; however, the MRI arm of the study was continued. Of the 362 subjects who underwent a baseline MRI study, 192 subjects underwent a second MRI 1 year later. Hippocampal volume and temporal horn volume were measured from the MRI scans.

RESULTS

The annualized percent changes in hippocampal volume (-4.9%) and temporal horn volume (16.1%) in the study patients were consistent with data from prior single-site studies. Correlations between the rate of MRI volumetric change and change in behavioral/cognitive measures were greater for the temporal horn than for the hippocampus. Decline over time was more consistently seen with imaging measures, 99% of the time for the hippocampus, than behavioral/cognitive measures (p < 0.001). Greater consistency in MRI than behavioral/clinical measures resulted in markedly lower estimated sample size requirements for clinical trials. The estimated number of subjects per arm required to detect a 50% reduction in the rate of decline over 1 year are: AD Assessment Scale-cognitive subscale 320; Mini-Mental Status Examination 241; hippocampal volume 21; temporal horn volume 54.

CONCLUSION

The consistency of MRI measurements obtained across sites, and the consistency between the multisite milameline data and that obtained in prior single-site studies, demonstrate the technical feasibility of using structural MRI measures as a surrogate endpoint of disease progression in therapeutic trials. However, validation of imaging as a biomarker of therapeutic efficacy in AD awaits a positive trial.