E. Stock

Aripiprazole in the treatment of schizophrenia: safety and tolerability in short-term, placebo-controlled trials

Aripiprazole is a novel antipsychotic with a unique mechanism of action. Presented here is a pooled analysis of safety and tolerability data from all completed short-term, placebo-controlled trials in schizophrenia from the aripiprazole clinical development program. Data were analyzed from five 4- to 6-week double-blind multicenter studies of patients hospitalized with acute relapse of schizophrenia or schizoaffective disorder randomized to aripiprazole (n=932), placebo (n=416), or haloperidol (n=201). Daily aripiprazole doses ranged from 2 to 30 mg. Safety assessments included adverse event (AE) reports, EPS scales, ECGs, weight, and prolactin, glucose and cholesterol levels. Aripiprazole was well tolerated, with similar AE incidence rates to placebo, and lower rates than haloperidol for akathisia, extrapyramidal syndrome and somnolence. Objective EPS assessments demonstrated no significant differences between aripiprazole and placebo on Simpson-Angus Scale (SAS) scores, no dose-dependent effects on Barnes Akathisia scores, and significant reductions in Abnormal Involuntary Movement Scale (AIMS) scores from baseline vs. placebo (p</=0.01). Haloperidol showed increased SAS and Barnes Akathisia scores over placebo (p</=0.01). There was minimal mean weight change with aripiprazole (+0.71 kg) and haloperidol (+0.56 kg), and a lack of QT(c) prolongation. Serum prolactin increased with haloperidol, but not aripiprazole. In conclusion, aripiprazole shows a favorable safety and tolerability profile with low potential for EPS, weight gain, prolactin elevation, QT(c) prolongation, and sedation. Aripiprazoles safety profile may offer benefits in schizophrenia treatment.

Aripiprazole in the treatment of acute manic or mixed episodes in patients with bipolar I disorder: a 3-week placebo-controlled study.

This study compares the efficacy, safety, and tolerability of a partial dopamine agonist, aripiprazole, with placebo in the treatment of patients with bipolar I disorder experiencing an acute manic or mixed episode. In total, 272 hospitalized patients were randomized to aripiprazole 30mg/day or placebo in this 3-week, double-blind, placebo-controlled trial. Dosing could be reduced to 15mg/day for tolerability and, subsequently, increased to 30mg/day based on clinical response. Primary efficacy measure was mean change from baseline to endpoint in Young Mania Rating Scale (YMRS) total score; response was defined as 50% decrease from baseline YMRS score. Aripiprazole-treated patients demonstrated significantly greater improvement from baseline to endpoint in mean YMRS total scores compared with placebo-treated patients as early as Day 4 and sustained through Week 3. A significantly higher response rate was observed in aripiprazole-treated patients (53% vs. 32% at endpoint). Aripiprazole produced significantly greater improvements from baseline on other efficacy assessments compared with placebo, including Clinical Global Impression – Bipolar Version Severity and Improvement scores. The 30mg/day dose was maintained by 85% of aripiprazole-treated patients. Incidence of discontinuations due to adverse events was similar for aripiprazole (8.8%) and placebo (7.5%). Aripiprazole treatment resulted in no significant difference from placebo in change in mean body weight and was not associated with elevated serum prolactin or QTc prolongation. In conclusion, aripiprazole demonstrated superior efficacy to placebo in the treatment of patients with bipolar I disorder presenting with acute manic or mixed episodes, and exhibited a favourable safety and tolerability profile.

Multicenter, randomized, double‐blind, active comparator and placebo‐controlled trial of a corticotropin‐releasing factor receptor‐1 antagonist in generalized anxiety disorder

Background: Antagonism of corticotropin‐releasing factor (CRF) receptors has been hypothesized as a potential target for the development of novel anxiolytics. This study was designed to determine the safety and efficacy of pexacerfont, a selective CRF‐1 receptor antagonist, in the treatment of generalized anxiety disorder (GAD). Method: This was a multicenter, randomized, double‐blind, placebo‐controlled and active comparator trial. Two hundred and sixty patients were randomly assigned to pexacerfont 100 mg/day (after a 1 week loading dose of 300 mg/day), placebo or escitalopram 20 mg/day in a 2:2:1 ratio. The primary outcome was the mean change from baseline to end point (week 8) in the Hamilton Anxiety Scale total score. Results: Pexacerfont 100 mg/day did not separate from placebo on the primary outcome measure. The half‐powered active comparator arm, escitalopram 20 mg/day, demonstrated efficacy with significant separation from placebo at weeks 1, 2, 3, 6, and 8 (P<.02). Response rates for pexacerfont, placebo, and escitalopram were 42, 42, and 53%, respectively. Genetic and psychometric rating scale data was obtained in 175 randomized subjects. There was a significant association between a single nucleotide polymorphism (SNP) of the gene encoding plexin A2 (PLXNA2‐2016) with the HAM‐A psychic subscale score for the entire cohort at baseline (FDR‐adjusted P=.015). Conclusions: Pexacerfont did not demonstrate efficacy compared to placebo for the treatment of GAD. Whether these findings are generalizable to this class of agents remains to be determined. Our preliminary genetic finding of an association between a SNP for the gene encoding plexin A2 and an anxiety phenotype in this study merits further exploration. The trial was registered at clinicaltrials.gov (NCT00481325) before enrollment. Depression and Anxiety, 2010.

Management of acute agitation in patients with bipolar disorder: efficacy and safety of intramuscular aripiprazole.

To investigate the efficacy and safety of intramuscular (IM) aripiprazole for the treatment of agitation in patients with bipolar I disorder, manic or mixed episodes. In total, 301 patients experiencing acute agitation were randomized to IM aripiprazole 9.75 mg per injection (n = 78), IM aripiprazole 15 mg per injection (n = 78), IM lorazepam 2 mg per injection (n = 70), or IM placebo (n = 75) in this double-blind multicenter study. Patients could receive up to 3 injections over 24 hours. Primary efficacy measure was mean change in Positive and Negative Syndrome Scale Excited Component score from baseline at 2 hours after first injection. Mean improvements in Positive and Negative Syndrome Scale Excited Component score at 2 hours were significantly greater with IM aripiprazole (9.75 mg, −8.7; 15 mg, −8.7) and IM lorazepam (−9.6) versus IM placebo (−5.8; P ≤ 0.001). For all other efficacy measures, all 3 active treatments showed significantly greater improvements over IM placebo at 2 hours (P < 0.05), with similar improvements across the active treatments. Significant differences over IM placebo were seen by 45 to 60 minutes for several efficacy parameters. Both IM aripiprazole doses were well tolerated; the safety profile was similar to oral aripiprazole. Oversedation (Agitation-Calmness Evaluation Scale score of 8 or 9) during 2 hours after first injection was less frequent with IM aripiprazole 9.75 mg (6.7%) and IM placebo (6.8%) versus IM aripiprazole 15 mg (17.3%) and IM lorazepam (19.1%). IM aripiprazole 9.75 and 15 mg are effective and well tolerated for acute agitation in bipolar disorder, although the low incidence of oversedation suggests a risk-benefit profile for IM aripiprazole 9.75 mg.

Intramuscular aripiprazole or haloperidol and transition to oral therapy in patients with agitation associated with schizophrenia: sub-analysis of a double-blind study.

ABSTRACT Objective: A sub-population analysis of 325 patients with agitation (Positive and Negative Syndrome Scale Excited Component [PEC] score ≥ 15 and ≤ 32; score of ≥ 4 on ≥ 2 items) associated with schizophrenia in a randomized, double-blind study investigating the efficacy and tolerability of intramuscular (IM) aripiprazole 9.75 mg, IM haloperidol 6.5 mg, or IM placebo and the transition to oral therapy. Research design and methods: Over 24 h, patients could receive up to three IM injections; the second and third administered ≥ 2 and ≥ 4 h, respectively, after the first, if deemed clinically necessary. Following IM treatment, oral aripiprazole or haloperidol was administered for 4 days. The primary efficacy measure was the mean change in PEC score from baseline at 2 h. Results: At 2 h, mean improvements in PEC scores with IM aripiprazole (–8.0) were significantly greater versus IM placebo (–5.7; p ≤ 0.01), and similar versus IM haloperidol (–8.3). Secondary efficacy measures also significantly improved with active IM treatment versus IM placebo. Continuation with oral treatment provided continued efficacy with both active treatments. The safety profiles of IM and oral aripiprazole were similar. The incidence of extrapyramidal symptom-related adverse events was 0% with IM aripiprazole, 1.6% with IM placebo and 16.5% with IM haloperidol. Conclusion: Intramuscular aripiprazole is effective in patients with acute agitation associated with schizophrenia, comparable to IM haloperidol, and enables convenient transfer to oral aripiprazole therapy.