Mitigation of Olanzapine-Induced Weight Gain With Samidorphan, an Opioid Antagonist: A Randomized Double-Blind Phase 2 Study in Patients With Schizophrenia.

OBJECTIVE: Preclinical evidence and data from a proof-of-concept study in healthy volunteers suggest that samidorphan, an opioid antagonist, mitigates weight gain associated with olanzapine. This study prospectively compared combination therapy of olanzapine plus either samidorphan or placebo for the treatment of schizophrenia. METHODS: This was an international, multicenter, randomized phase 2 study of olanzapine plus samidorphan in patients with schizophrenia. The study had a 1-week open-label olanzapine lead-in period followed by a 12-week double-blind treatment phase in which patients were randomly assigned in a 1:1:1:1 ratio to receive olanzapine plus placebo (N=75) or olanzapine plus 5 mg (N=80), 10 mg (N=86), or 20 mg (N=68) of samidorphan. The primary aims were to confirm that the antipsychotic efficacy of olanzapine plus samidorphan was comparable to olanzapine plus placebo, to assess the effect of combining olanzapine with samidorphan on olanzapine-induced weight gain, and to assess the overall safety and tolerability of olanzapine plus samidorphan. RESULTS: Antipsychotic efficacy, as assessed by total score on the Positive and Negative Syndrome Scale (PANSS), was equivalent across all treatment groups. Treatment with olanzapine plus samidorphan resulted in a statistically significant lower weight gain (37% lower weight gain compared with olanzapine plus placebo). The least square mean percent change from baseline in body weight was 4.1% (2.9 kg) for the olanzapine plus placebo group and 2.6% (1.9 kg) for the olanzapine plus samidorphan group (2.8% [2.1 kg] for the 5 mg group, 2.1% [1.5 kg] for the 10 mg group, and 2.9% [2.2 kg] for the 20 mg group). Adverse events reported at a frequency ≥5% in any of the olanzapine plus samidorphan groups and occurring at a rate ≥2 times greater than in the olanzapine plus placebo group were somnolence, sedation, dizziness, and constipation. Other safety measures were comparable between the olanzapine plus samidorphan groups and the olanzapine plus placebo group. CONCLUSIONS: The antipsychotic efficacy of olanzapine plus samidorphan was equivalent to that of olanzapine plus placebo, and olanzapine plus samidorphan was associated with clinically meaningful and statistically significant mitigation of weight gain compared with olanzapine plus placebo. Olanzapine plus samidorphan was generally well tolerated, with a safety profile similar to olanzapine plus placebo.

Endogenous opioid system dysregulation in depression: implications for new therapeutic approaches.

The United States is in the midst of an opioid addiction and overdose crisis precipitated and exacerbated by use of prescription opioid medicines. The majority of opioid prescriptions are dispensed to patients with comorbid mood disorders including major depressive disorder (MDD). A growing body of research indicates that the endogenous opioid system is directly involved in the regulation of mood and is dysregulated in MDD. This involvement of the endogenous opioid system may underlie the disproportionate use of opioids among patients with mood disorders. Emerging approaches to address endogenous opioid dysregulation in MDD may yield novel therapeutics that have a low or absent risk of abuse and addiction relative to µ-opioid agonists. Moreover, agents targeting the endogenous opioid system would be expected to yield clinical benefits qualitatively different from conventional monaminergic antidepressants. The development of safe and effective agents to treat MDD-associated endogenous opioid dysregulation may represent a distinct and currently underappreciated means of addressing treatment resistant depression with the potential to attenuate the on-going opioid crisis.

Effect of Aripiprazole Lauroxil on Metabolic and Endocrine Profiles and Related Safety Considerations Among Patients With Acute Schizophrenia.

OBJECTIVE: Aripiprazole lauroxil, a long-acting injectable antipsychotic, demonstrated safety and efficacy in treating symptoms of schizophrenia in a double-blind, placebo-controlled trial. Because the metabolic profile of antipsychotics is an important safety feature, the effects of aripiprazole lauroxil on body weight, endocrine and metabolic profiles, and safety were examined in a secondary analysis. METHODS: Patients with schizophrenia (DSM-IV-TR criteria) were randomly assigned to aripiprazole lauroxil 441 mg, aripiprazole lauroxil 882 mg, or placebo intramuscularly once monthly between December 2011 and March 2014. Changes in body weight, body mass index, fasting blood glucose and serum lipids, glycosylated hemoglobin (HbA1c), and prolactin over 12 weeks were assessed. The incidence of treatment-emergent adverse events (AEs) was evaluated. RESULTS: Among 622 randomized patients, no clinically relevant changes from baseline to week 12 were observed for any serum lipid, lipoprotein, plasma glucose, or HbA1c value with placebo or either dose of aripiprazole lauroxil. Both doses of aripiprazole lauroxil were associated with reductions in mean prolactin levels, whereas placebo treatment was not. The mean (standard deviation) change from baseline for body weight was 0.74 (3.9) kg, 0.86 (3.7) kg, and 0.01 (3.6) kg for aripiprazole lauroxil 441 mg, aripiprazole lauroxil 882 mg, and placebo groups, respectively. AEs related to metabolic parameters were reported in 2.4%, 1.4%, and 2.4% of patients in the aripiprazole lauroxil 441 mg, aripiprazole lauroxil 882 mg, and placebo groups, respectively. CONCLUSIONS: Aripiprazole lauroxil was well tolerated, with a low-risk metabolic profile relative to published data for other antipsychotics. Changes similar to those observed with placebo were observed in the aripiprazole lauroxil groups for metabolic parameters, with modest weight gain in the active treatment groups over the 12-week course. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01469039.

Effect of aripiprazole lauroxil on agitation and hostility in patients with schizophrenia.

This study aimed to evaluate the effects of aripiprazole lauroxil on hostility and aggressive behavior in patients with schizophrenia. Patients aged 18-70 years with a diagnosis of schizophrenia and currently experiencing an acute exacerbation or relapse were randomized to intramuscular (IM) aripiprazole lauroxil 441 mg (n=207), 882 mg (n=208), or placebo (n=207) for 12 weeks. In post-hoc analyses, hostility and aggression were assessed by the Positive and Negative Syndrome Scale (PANSS) Hostility item (P7) and a specific antihostility effect was assessed by adjusting for positive symptoms of schizophrenia, somnolence, and akathisia. The PANSS excited component score [P4 (Excitement), P7 (Hostility), G4 (Tension), G8 (Uncooperativeness), and G14 (Poor impulse control)], and the Personal and Social Performance scale disturbing and aggressive behavior domain were also assessed. Of the 147 patients who received aripiprazole lauroxil 882 mg and with a baseline PANSS Hostility item P7 more than 1, there was a significant (P<0.05) improvement versus placebo on the PANSS Hostility item P7 score by mixed-model repeated-measures at the end of the study, which remained significant when PANSS-positive symptoms and somnolence or akathisia were included as additional covariates. The proportion with PANSS Hostility item P7 more than 1 at endpoint was significantly (P<0.05) lower with aripiprazole lauroxil versus placebo (53.6, 46.1, and 66.3% for 441, 882 mg, and placebo). A significant (P<0.05) improvement was found with aripiprazole lauroxil versus placebo for change from baseline in the PANSS excited component score. The proportion of patients with aggressive behavior on the Personal and Social Performance scale was significantly (P<0.05) lower for aripiprazole lauroxil: 30.0% for 441 mg versus 44.1% for placebo (P=0.006) and 22.2% for 881 mg (P<0.001 versus placebo). Treatment with aripiprazole lauroxil resulted in decreases in agitation and hostility in patients with schizophrenia and this antihostility effect appears to be independent of a general antipsychotic effect.

A randomized, double-blind, placebo-controlled trial of aripiprazole lauroxil in acute exacerbation of schizophrenia.

OBJECTIVE: This study evaluated the efficacy, safety, and tolerability of aripiprazole lauroxil, a novel long-acting injectable atypical antipsychotic, for the treatment of schizophrenia. METHOD: An international multicenter, randomized, double-blind, placebo-controlled trial was conducted between December 2011 and March 2014. Patients (N = 623) aged 18 to 70 years with schizophrenia (DSM-IV-TR criteria), experiencing an acute exacerbation, were randomized in a 1:1:1 ratio to receive gluteal intramuscular injection of aripiprazole lauroxil 441 mg, aripiprazole lauroxil 882 mg, or matching placebo once monthly for 12 weeks. The primary efficacy outcome was change in Positive and Negative Syndrome Scale (PANSS) total score from baseline to day 85. The Clinical Global Impressions-Improvement scale (CGI-I) score at day 85 was the secondary efficacy outcome. Safety and tolerability were assessed. RESULTS: The PANSS total score (mean ± standard error [SE]) improved significantly from baseline to day 85 in the aripiprazole lauroxil 441 mg and 882 mg groups, with placebo-adjusted differences of -10.9 ± 1.8 (P < .001) and -11.9 ± 1.8 (P < .001), respectively. Significant (P ≤ .004) improvements in both active treatment groups were demonstrated as early as day 8 and continued throughout the treatment period. The proportion of patients who were very much or much improved on the CGI-I was significantly greater with aripiprazole lauroxil 441 mg and 882 mg treatment versus placebo (P < .001). The most common treatment-emergent adverse events were insomnia, akathisia, headache, and anxiety. The incidence of injection site reactions was low, predominantly described as injection site pain, and was associated with the first injection. CONCLUSIONS: Aripiprazole lauroxil demonstrated robust efficacy for treatment of patients experiencing acute exacerbation of schizophrenia. The improvement in psychotic symptoms was statistically significant and clinically meaningful. Symptom improvement occurred rapidly after initiation of aripiprazole lauroxil treatment and was maintained throughout the study. Both aripiprazole lauroxil 441 mg and 882 mg doses were well tolerated. These results support aripiprazole lauroxil as an important new treatment option for schizophrenia. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01469039; Clinicaltrialsregister.eu identifier: 2012-003445-15.

Relative bioavailability and safety of aripiprazole lauroxil, a novel once-monthly, long-acting injectable atypical antipsychotic, following deltoid and gluteal administration in adult subjects with schizophrenia.

Aripiprazole lauroxil is a linker lipid ester of aripiprazole for extended-release intramuscular (IM) injection. This multicenter, randomized, open-label study evaluated the pharmacokinetics (PK), relative bioavailability, and tolerability of a single IM deltoid or gluteal injection of aripiprazole lauroxil in adult subjects with chronic stable schizophrenia or schizoaffective disorder. Forty-six subjects were randomized 1:1 to aripiprazole lauroxil 441 mg IM in the deltoid or gluteal muscle. Samples were collected through 89 days post-dose to measure levels of aripiprazole lauroxil, N-hydroxymethyl aripiprazole, aripiprazole, and dehydro-aripiprazole. Forty-three (93.5%) subjects completed all study assessments; most were CYP2D6 extensive or immediate metabolizers (96%); two (4%) were poor metabolizers. The PK of aripiprazole following aripiprazole lauroxil was characterized by a steady rise in plasma concentrations (Tmax 44-50 days), a broad peak, and prolonged exposure attributable to the dissolution of aripiprazole lauroxil and formation rate-limited elimination of aripiprazole (t1/2=15.4-19.2 days). Deltoid vs. gluteal administration resulted in slightly higher Cmax aripiprazole concentrations [1.31 (1.02, 1.67); GMR 90% CI]; total exposure (AUCinf) was similar between sites of administration [0.84 (0.57, 1.24)]. N-hydroxymethyl-aripiprazole and dehydro-aripiprazole exposures were 10% and 33-36%, respectively, of aripiprazole exposure following aripiprazole lauroxil. The most common adverse events were injection site pain in 20 subjects (43.5%) and headache in 6 subjects (13.0%) of mild intensity occurring at a similar rate with deltoid and gluteal administration. Exposure ranges with deltoid and gluteal administration overlapped, suggesting that these sites may be used interchangeably. Despite a higher incidence of adverse events, deltoid muscle provides a more accessible injection site and could facilitate patient acceptance.

A placebo-controlled pilot study of the novel opioid receptor antagonist ALKS-33 in binge eating disorder.

OBJECTIVE: To assess preliminarily the effectiveness of a novel opioid antagonist, ALKS-33, in binge eating disorder (BED). METHOD: In this randomized, placebo-controlled, flexible dose, proof-of-concept trial, 62 outpatients with BED and obesity received ALKS-33 (N = 26) or placebo (N = 36) for 6 weeks. Outcome measures of binge eating, body weight, and eating pathology were assessed. RESULTS: A large decrease in binge eating episode frequency was observed following both ALKS-33 and placebo treatment. There was no significant difference between treatment groups in binge eating episode frequency or any other measure of binge eating, body weight, or eating pathology. DISCUSSION: In this preliminary proof-of-concept study in BED, ALKS-33 did not separate from placebo. Although a failed trial cannot be excluded, the finding is consistent with earlier observations in bulimia nervosa with other opioid antagonists and suggests ALKS-33, at least when administered daily for 6 weeks, may not be efficacious for BED.

Single- and multiple-dose pharmacokinetics of long-acting injectable naltrexone.

BACKGROUND: Oral naltrexone is effective in the treatment of alcohol dependence; however, a major limitation of its clinical utility is poor patient adherence to the daily dosing schedule. A biodegradable, long-acting naltrexone microsphere formulation was developed to achieve continuous naltrexone exposure for 1 month in the treatment of alcohol dependence. METHODS: The single- and multiple-dose safety and pharmacokinetics of a long-acting naltrexone microsphere preparation were evaluated in healthy subjects. One group of subjects (n = 28) received a single dose of oral naltrexone 50 mg followed by a single gluteal intramuscular (IM) injection of long-acting naltrexone 190 or 380 mg or placebo. A different group of subjects (n = 14) received oral naltrexone 50 mg daily for 5 days, followed by IM long-acting naltrexone 380 mg or placebo every 28 days for a total of 4 doses. A 7-day washout period separated oral and IM administrations. Blood samples were collected to determine plasma concentrations of naltrexone and the primary metabolite, 6beta-naltrexol. RESULTS: After a single IM injection of long-acting naltrexone 380 mg, naltrexone plasma concentrations were measurable in all subjects for at least 31 days postdose. The pharmacokinetics were proportional to the dose and multiple dose observations were consistent with single dose observations. Mean apparent elimination half-lives for naltrexone and 6beta-naltrexol ranged from 5 to 7 days. Exposure to 6beta-naltrexol was reduced with IM injection compared with that oral administration. No serious adverse events occurred. CONCLUSIONS: This study demonstrated that the long-acting naltrexone formulation was well tolerated, displayed predictable pharmacokinetics, and resulted in no meaningful drug accumulation upon multiple dosing. Intramuscular administration avoids first-pass metabolism and changes the exposure ratio of 6beta-naltrexol to naltrexone compared with oral administration. By providing continuous exposure to naltrexone for several weeks following IM injection, this long-acting naltrexone formulation may offer therapeutic benefit to those patients who experience difficulty adhering to the daily administration schedule necessitated by oral naltrexone therapy.

Pharmacokinetics of long-acting naltrexone in subjects with mild to moderate hepatic impairment.

Long-acting naltrexone is an extended-release formulation developed with the goal of continuous naltrexone exposure for 1 month for the treatment of alcohol dependence. The influence of mild and moderate hepatic impairment on naltrexone pharmacokinetics following long-acting naltrexone 190-mg administration was assessed. Subjects with mild (Child-Pugh grade A) and moderate (Child-Pugh grade B) hepatic impairment (n = 6 per group) and matched control subjects (n = 13) were enrolled. Naltrexone and 6beta-naltrexol concentrations were determined over a period of 63 days following a single intramuscular dose. Naltrexone and 6beta-naltrexol concentrations were detected in all subjects through 28 days. Total exposure (AUC(0-infinity)) of naltrexone and 6beta-naltrexol was similar across all groups. The long apparent half-lives of naltrexone and 6beta-naltrexol (5-8 days) were attributed to the slow release of naltrexone (long-acting naltrexone exhibits absorption rate-limited elimination or "flip-flop" kinetics); elimination was not altered in subjects with hepatic impairment. Based on pharmacokinetic considerations, the dose of long-acting naltrexone does not need to be adjusted in patients with mild or moderate hepatic impairment.

Efficacy and tolerability of long-acting injectable naltrexone for alcohol dependence: a randomized controlled trial.

CONTEXT: Alcohol dependence is a common disorder associated with significant morbidity and mortality. Naltrexone, an opioid antagonist, has been shown to be effective for treatment of alcohol dependence. However, adherence to daily oral pharmacotherapy can be problematic, and clinical acceptance and utility of oral naltrexone have been limited. OBJECTIVE: To determine efficacy and tolerability of a long-acting intramuscular formulation of naltrexone for treatment of alcohol-dependent patients. DESIGN, SETTING, AND PARTICIPANTS: A 6-month, randomized, double-blind, placebo-controlled trial conducted between February 2002 and September 2003 at 24 US public hospitals, private and Veterans Administration clinics, and tertiary care medical centers. Of the 899 individuals screened, 627 who were diagnosed as being actively drinking alcohol-dependent adults were randomized to receive treatment and 624 received at least 1 injection. INTERVENTION: An intramuscular injection of 380 mg of long-acting naltrexone (n = 205) or 190 mg of long-acting naltrexone (n = 210) or a matching volume of placebo (n = 209) each administered monthly and combined with 12 sessions of low-intensity psychosocial intervention. MAIN OUTCOME MEASURE: The event rate of heavy drinking days in the intent-to-treat population. RESULTS: Compared with placebo, 380 mg of long-acting naltrexone resulted in a 25% decrease in the event rate of heavy drinking days (P = .02) [corrected] and 190 mg of naltrexone resulted in a 17% decrease (P = .07). Sex and pretreatment abstinence each showed significant interaction with the medication group on treatment outcome, with men and those with lead-in abstinence both exhibiting greater treatment effects. Discontinuation due to adverse events occurred in 14.1% in the 380-mg and 6.7% in the 190-mg group and 6.7% in the placebo group. Overall, rate and time to treatment discontinuation were similar among treatment groups. CONCLUSIONS: Long-acting naltrexone was well tolerated and resulted in reductions in heavy drinking among treatment-seeking alcohol-dependent patients during 6 months of therapy. These data indicate that long-acting naltrexone can be of benefit in the treatment of alcohol dependence.

Dose-effect relationships of nonsteroidal anti-inflammatory drugs: a literature review.

BACKGROUND: Many clinicians believe that higher doses of nonsteroidal anti-inflammatory drugs (NSAIDs) are more effective than lower doses for the treatment of rheumatoid arthritis (RA) and osteoarthritis (OA) but are associated with higher rates of adverse events (AEs). However, there is a lack of consensus on dose-effect relationships with the NSAIDs. OBJECTIVE: The purpose of this review was to investigate evidence for the relationship between NSAID dose, efficacy, and the occurrence of AEs from clinical trials of RA and OA of the hip and knee. METHODS: Relevant English-language publications were identified through a search of EMBASE, MEDLINE, and REFLINE using the terms aceclofenac, diclofenac, etodolac, ibuprofen, isoxicam, lornoxicam, meloxicam, nabumetone, naproxen, piroxicam, tenidap, tenoxicam, arthritis, OA (hip and knee), RA, rheumatic disorders, and musculoskeletal disorders for the period January 1970 to December 1997 (this review was conducted in 1998). Bibliographies of retrieved publications were reviewed for other potentially relevant articles. Selected publications were evaluated for quality (likelihood of bias) based on 4 factors (randomization procedure; completeness of patient and treatment information; standardization and completeness of outcome data; and reporting of attrition data). RESULTS: This review included 99 publications concerning clinical trials conducted in 24 countries and enrolling 28,239 patients. The majority of reports were published in the 1990s, particularly in the latter half of that decade. The average quality of the publications improved over time, with a significant increase in mean quality score from 5.43 in the 1970s to 9.21 during the last half of the 1990s (P < 0.05). Only 8 reports directly compared high and low doses of the same drug in relation to efficacy. CONCLUSIONS: Data on the relationship of NSAID dose to efficacy and the incidence of AEs were limited. There is a need for clinical trials directly addressing dose-effect relationships of NSAIDs, as well as reviews of more current literature and reports in languages other than English.