Safety and Efficacy of Memantine in Children with Autism: Randomized, Placebo-Controlled Study and Open-Label Extension.
ABSTRACT: Abnormal glutamatergic neurotransmission is implicated in the pathophysiology of autism spectrum disorder (ASD). In this study, the safety, tolerability, and efficacy of the glutamatergic N-methyl-d-aspartate (NMDA) receptor antagonist memantine (once-daily extended-release [ER]) were investigated in children with autism in a randomized, placebo-controlled, 12 week trial and a 48 week open-label extension.A total of 121 children 6-12 years of age with Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text Revision (DSM-IV-TR)-defined autistic disorder were randomized (1:1) to placebo or memantine ER for 12 weeks; 104 children entered the subsequent extension trial. Maximum memantine doses were determined by body weight and ranged from 3 to 15?mg/day.There was one serious adverse event (SAE) (affective disorder, with memantine) in the 12 week study and one SAE (lobar pneumonia) in the 48 week extension; both were deemed unrelated to treatment. Other AEs were considered mild or moderate and most were deemed not related to treatment. No clinically significant changes occurred in clinical laboratory values, vital signs, or electrocardiogram (ECG). There was no significant between-group difference on the primary efficacy outcome of caregiver/parent ratings on the Social Responsiveness Scale (SRS), although an improvement over baseline at Week 12 was observed in both groups. A trend for improvement at the end of the 48 week extension was observed. No improvements in the active group were observed on any of the secondary end-points, with one communication measure showing significant worsening with memantine compared with placebo (p?=?0.02) after 12 weeks.This trial did not demonstrate clinical efficacy of memantine ER in autism; however, the tolerability and safety data were reassuring. Our results could inform future trial design in this population and may facilitate the investigation of memantine ER for other clinical applications.
Project description:Three phase 2 trials were conducted to assess the efficacy and long-term safety of weight-based memantine extended release (ER) treatment in children with autism spectrum disorder. MEM-MD-91, a 50-week open-label trial, identified memantine extended-release treatment responders for enrollment into MEM-MD-68, a 12-week randomized, double-blind, placebo-controlled withdrawal trial. MEM-MD-69 was an open-label extension trial in which participants from MEM-MD-68, MEM-MD-91, and open-label trial MEM-MD-67 were treated ?48?weeks with memantine extended release. In MEM-MD-91, 517 (59.6%) participants were confirmed Social Responsiveness Scale responders at week 12; mean Social Responsiveness Scale total raw scores improved two to three times a minimal clinically important difference of 10 points. In MEM-MD-68, there was no difference between memantine and placebo on the primary efficacy parameter, the proportion of patients with a loss of therapeutic response (defined as ?10-point increase from baseline in Social Responsiveness Scale total raw score). MEM-MD-69 exploratory analyses revealed mean standard deviation improvement in Social Responsiveness Scale total raw score of 32.4 (26.4) from baseline of the first lead-in study. No new safety concerns were evident. While the a priori-defined efficacy results of the double-blind trial were not achieved, the considerable improvements in mean Social Responsiveness Scale scores from baseline in the open-label trials were presumed to be clinically important.
Project description:To evaluate the long-term safety and efficacy of memantine use as treatment of HIV-associated cognitive impairment.The results of a 20-week, randomized, double-blind, placebo-controlled trial of memantine in HIV-infected participants with cognitive impairment (ACTG 301) were previously reported. We report the results of the up-to-60-week open-label phase following the double-blind phase.Participants received open-label memantine and were escalated to a 40 mg/day dose or their maximum tolerated dose in the double- blind phase. Adverse experiences were used to evaluate safety, and changes in the mean of eight neuropsychological test scores (NPZ-8) were used to evaluate efficacy.Ninety-nine participants entered the initial 12-week open-label phase and 45 in the additional 48-week extension. Twenty-seven participants reported severe adverse experiences. During the initial 12-week open-label phase, participants randomized to memantine in the double-blind phase had a statistically significant higher improvement in NPZ-8 compared to those randomized to placebo in the double-blind phase. No statistically significant NPZ-8 changes were detected during the 48-week extension.Long-term use of memantine appears safe and tolerable. Future randomized studies with longer follow-up are necessary to establish efficacy of memantine for the treatment of HIV-associated cognitive impairment.
Project description:Memantine extended release (ER) significantly outperformed placebo on co-primary endpoints of Clinician's Interview-based Impression of Change Plus Caregiver Input (CIBIC-Plus) and baseline to endpoint changes on the Severe Impairment Battery (SIB) in a 24-week, randomized trial (NCT00322153) in patients with moderate to severe Alzheimer's disease taking a cholinesterase inhibitor (ChEI). A post hoc analysis compared patients receiving memantine ER/ChEI to placebo/ChEI for time to onset of response and if the response was maintained (achieving improvement at weeks 8, 12, or 18 and maintaining through endpoint/week 24) on the SIB, the Neuropsychiatric Inventory (NPI), CIBIC-Plus, and Activities of Daily Living (ADL) using Fisher exact test. A second post hoc analysis compared percentages of patients for all possible combinations of 2 to 4 assessments with either no decline or clinically notable response using Wald χ. Significantly greater percentages of memantine ER/ChEI patients achieved an early response that was maintained on SIB, NPI, and CIBIC-Plus (P<0.05) versus placebo/ChEI. Significantly greater percentages of memantine ER/ChEI-treated patients achieved and maintained a clinically notable response on ADL/NPI, SIB/ADL/NPI, and SIB/ADL/CIBIC-Plus, compared with placebo/ChEI (P<0.05). Memantine ER results in early, maintained improvement in patients with moderate to severe Alzheimer's disease concurrently taking ChEIs, compared with cholinesterase treatment alone.
Project description:Cognitive impairment affects up to 80% of systemic lupus erythematosus (SLE) patients within 10 years of diagnosis. Memantine, a seronergic receptor and nicotine acetylcholine receptor antagonist, acts on the glutamatergic system through the NMDA receptor and is used to treat dementia. We investigated whether it had benefit for SLE cognitive impairment.A randomized double-blind, placebo-controlled single-center 12-week trial of memantine titrated to 20 mg/d was performed, using a 2:1 randomization ratio, in 51 SLE patients. The primary outcome measures were change in the Automated Neuropsychological Assessment Metrics throughput scores at 12 weeks.There were no statistically significant differences between treatment groups or change from baseline in any of the Automated Neuropsychological Assessment Metrics throughput scores at 6 or 12 weeks. For the American College of Rheumatology cognitive battery, the only statistically significant findings were for the Controlled Oral Word Association Test-S words at 6 and 12 weeks. At 12 weeks, the memantine group exhibited greater improvement compared with the placebo group (3.6 ± 1.8 vs 0.5 ± 3.8 words, P = 0.03). In a subset analysis limited to patients that scored ?1 standard deviation below normal controls at baseline, no significant differences between treatment groups were found.In this first clinical trial of memantine in SLE, patients treated with memantine did not exhibit significant improvement in cognitive performance compared with the placebo group, regardless of the degree of impairment at baseline, with the exception of controlled oral word association.
Project description:The objective of this trial, Biomarkers in Autism of Aripiprazole and Risperidone Treatment (BAART), was to provide support and guidance for an evidence-based approach for the selection and monitoring of initial pharmacotherapy in patients with autism by assessing predictors of efficacy, tolerability, and safety. This randomized double-blind parallel-group study was conducted in three academic medical centers and a single private pediatric practice. Eighty children or adolescents (aged 6-17 yrs) with autistic disorder were enrolled, and 61 patients were randomized to the study drug. Of those patients, 51 completed the 10-week trial, and 31 completed an optional 12-week blinded extension phase. All patients were treated with 2 weeks of placebo before random assignment to receive aripiprazole (31 patients) or risperidone (30 patients) for 10 weeks. Sixteen placebo responders (20%) were excluded from further analysis. Drug dosing followed U.S. Food and Drug Administration (FDA) labeling, and weekly dosage adjustments were allowed until week 4; patients were then maintained on a fixed dose for 6 additional weeks. Safety, physical, and psychological assessments were recorded weekly or every 2 weeks. No significant differences in severity of illness between the aripiprazole and risperidone groups were noted at baseline. All patients significantly improved on the Aberrant Behavior Checklist-Irritability subscale after 1 week and continued for the remaining 9 weeks and the extension phase. Improvement was greatest in the risperidone group at every assessment period and was statistically significantly better than that in the aripiprazole group at weeks 3 and 6 (p<0.05). No dose-limiting adverse events occurred during the dose-titration period. Mean weight gain in the aripiprazole group was significantly less than that in the risperidone group at week 4 (0.62 vs 1.38 kg, p=0.033) and week 10 (1.61 vs 3.31 kg, p<0.001), but the difference became nonsignificant for the 31 patients completing the 3-month extension phase (4.36 vs 5.55 kg, p=0.26). Pharmacotherapy of patients with autism spectrum disorder resulted in behavioral improvement within 1 week and lasted at least 22 weeks. Weight gain occurred to a greater degree with risperidone than aripiprazole initially, but the differences became nonsignificant by the end of the trial. Our trial supports previous results of drug efficacy and safety in patients with autism spectrum disorder from other trials and extends the evidence-based support for choosing an FDA-approved drug for initial pharmacotherapy for autism spectrum disorder.
Project description:Lockwood2006 - AlzheimersDisease PBPK
A mathematical model to predict the
effectiveness of CI-1017 (muscarinic agonist) for Alzheimer's
disease by evaluating changes in ADAS-cog score.
This model is described in the article:
Application of clinical
trial simulation to compare proof-of-concept study designs for
drugs with a slow onset of effect; an example in Alzheimer's
Lockwood P, Ewy W, Hermann D,
Pharm. Res. 2006 Sep; 23(9):
OBJECTIVE: Clinical trial simulation (CTS) was used to
select a robust design to test the hypothesis that a new
treatment was effective for Alzheimer's disease (AD).
Typically, a parallel group, placebo controlled, 12-week trial
in 200-400 AD patients would be used to establish drug effect
relative to placebo (i.e., Ho: Drug Effect = 0). We evaluated
if a crossover design would allow smaller and shorter duration
trials. MATERIALS AND METHODS: A family of plausible drug and
disease models describing the time course of the AD assessment
scale (ADAS-Cog) was developed based on Phase I data and
literature reports of other treatments for AD. The models
included pharmacokinetic, pharmacodynamic, disease progression,
and placebo components. Eight alternative trial designs were
explored via simulation. One hundred replicates of each
combination of drug and disease model and trial design were
simulated. A 'positive trial' reflecting drug activity was
declared considering both a dose trend test (p < 0.05) and
pair-wise comparisons to placebo (p < 0.025). RESULTS: A 4 x
4 Latin Square design was predicted to have at least 80% power
to detect activity across a range of drug and disease models.
The trial design was subsequently implemented and the trial was
completed. Based on the results of the actual trial, a
conclusive decision about further development was taken. The
crossover design provided enhanced power over a parallel group
design due to the lower residual variability. CONCLUSION: CTS
aided the decision to use a more efficient proof of concept
trial design, leading to savings of up to US 4 M dollars in
direct costs and a firm decision 8-12 months earlier than a
12-week parallel group trial.
This model is hosted on
and identified by:
To cite BioModels Database, please use:
Chelliah V et al. BioModels: ten-year
anniversary. Nucl. Acids Res. 2015, 43(Database
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
Public Domain Dedication for more information.
Project description:BACKGROUND:Agitation in Alzheimer's disease (AD) is common and associated with poor patient life-quality and carer distress. The best evidence-based pharmacological treatments are antipsychotics which have limited benefits with increased morbidity and mortality. There are no memantine trials in clinically significant agitation but post-hoc analyses in other populations found reduced agitation. We tested the primary hypothesis, memantine is superior to placebo for clinically significant agitation, in patients with moderate-to-severe AD. METHODS AND FINDINGS:We recruited 153 participants with AD and clinically significant agitation from care-homes or hospitals for a double-blind randomised-controlled trial and 149 people started the trial of memantine versus placebo. The primary outcome was 6 weeks mixed model autoregressive analysis of Cohen-Mansfield Agitation Inventory (CMAI). Secondary outcomes were: 12 weeks CMAI; 6 and 12 weeks Neuropsychiatric symptoms (NPI), Clinical Global Impression Change (CGI-C), Standardised Mini Mental State Examination, Severe Impairment Battery. Using a mixed effects model we found no significant differences in the primary outcome, 6 weeks CMAI, between memantine and placebo (memantine lower -3.0; -8.3 to 2.2, p?=?0.26); or 12 weeks CMAI; or CGI-C or adverse events at 6 or 12 weeks. NPI mean difference favoured memantine at weeks 6 (-6.9; -12.2 to -1.6; p?=?0.012) and 12 (-9.6; -15.0 to -4.3 p?=?0.0005). Memantine was significantly better than placebo for cognition. The main study limitation is that it still remains to be determined whether memantine has a role in milder agitation in AD. CONCLUSIONS:Memantine did not improve significant agitation in people with in moderate-to-severe AD. Future studies are urgently needed to test other pharmacological candidates in this group and memantine for neuropsychiatric symptoms. TRIAL REGISTRATION:ClinicalTrials.gov NCT00371059. TRIAL REGISTRATION:International Standard Randomised Controlled Trial 24953404.
Project description:Compulsivity is a cross-disorder trait underlying phenotypically distinct psychiatric disorders that emerge in childhood or adolescence. Despite the effectiveness of serotonergic compounds in the treatment of obsessive-compulsive disorder, treatment-resistant symptoms remaining in 40 to 60 % of patients present a pressing clinical problem. There are currently no medications that effectively treat the core impairments of autism spectrum disorder. There is an urgent need for the development of conceptually novel pharmacological strategies. Agents targeting glutamate neurotransmission, such as memantine, represent promising candidates. This proof-of-concept clinical study will allow pilot-testing of memantine for both clinical effectiveness and tolerability/safety. Memantine is an N-methyl-D-aspartate receptor antagonist, approved for the treatment of Alzheimer's dementia in a number of countries.This 12-week study has an add-on, randomised, double-blind, placebo-controlled design of treatment with memantine, including an up-titration phase (forced flexible dose design, 5-15 mg/day), in patients aged 6-17 years and 9 months with obsessive-compulsive disorder or autism spectrum disorder. It is planned to include patients with obsessive-compulsive disorder (N = 50) or autism spectrum disorder (N = 50) across four centres in three European countries. Patients will be randomly assigned to memantine or placebo in a 1:1 ratio. Primary objectives are the investigation of the effectiveness of memantine in paediatric patients for improving symptoms of compulsivity (primary outcome measure: total score on the Children's Yale-Brown Obsessive-Compulsive Scale) and to explore its tolerability and safety. Secondary objectives are to explore the effects of memantine at the level of structure, function and biochemistry of the fronto-striatal circuits, and to collect blood for genetic analyses and biomarkers. Tertiary objectives are to explore the role of new candidate genes and pathways for compulsivity by linking genes to clinical phenotypes, response to treatment, neurocognitive test performance, and key structural and functional neuroimaging measures of the fronto-striatal circuits and to explore biomarkers/proteomics for compulsivity traits.This study is part of the large, translational project TACTICS ( http://www.tactics-project.eu/ ) that is funded by the European Union and investigates the neural, genetic and molecular factors involved in the pathogenesis of compulsivity. Its results will provide clinically relevant solid information on potential new mechanisms and medication treatment in obsessive-compulsive and autism spectrum disorders.EudraCT Number: 2014-003080-38 , date of registration: 14 July 2014.
Project description:OBJECTIVE:Excitotoxic injury involving N-methyl-d-aspartate (NMDA) receptor hyperactivity contributes to epilepsy-related memory dysfunction (ERMD). Current treatment strategies for ERMD have limited efficacy and fail to target the underlying pathophysiology. The present pilot study evaluated the efficacy of memantine, an NMDA receptor antagonist, for the treatment of ERMD in adults with focal-onset seizures. METHODS:Subjects underwent cognitive testing at baseline, after a 13-week randomized, parallel-group, double-blinded phase (of memantine titrated to 10?mg bid or placebo), and following a 13-week open-label extension phase (of memantine titrated to 10?mg bid). The selective reminding test (SRT) continuous long-term retrieval (CLTR) score and 7/24 Spatial Recall Test learning score served as the primary outcome measures. Secondary measures included tests of attention span, fluency, visual construction, and response inhibition, as well as assessments of quality of life, depression, sleepiness, and side effects. RESULTS:Seventeen subjects contributed data to the blinded phase (n?=?8 memantine, n?=?9 placebo). No significant differences were seen between groups on the primary or secondary outcome measures. Pooled data at the end of the open-label phase from 10 subjects (initially randomized to memantine n?=?3 or placebo n?=?7) demonstrated statistically significant improvement from baseline in CLTR score, memory-related quality of life, spatial span, and response inhibition. No significant changes were evident in depression, sleepiness, side effects, or seizure frequency throughout the trial. SIGNIFICANCE:Results demonstrated no significant effect of memantine on cognition when assessed at the end of the blinded period. Pooled data at the end of the open-label phase showed significant improvement over baseline performance in measures of verbal memory, frontal-executive function, and memory-related quality of life. These improvements, however, may be due to practice effects and should be interpreted cautiously. Findings suggest a favorable safety profile of memantine in the setting of epilepsy.
Project description:The authors previously reported on a 2-by-2 randomized clinical trial of individual and combined treatment with atomoxetine (ATX) and parent training (PT) for attention-deficit/hyperactivity disorder (ADHD) symptoms and behavioral noncompliance in 128 5- to 14-year-old children with autism spectrum disorder. In the present report, they describe a 24-week extension of treatment responders and nonresponders.One-hundred seventeen participants from the acute trial (91%) entered the extension; 84 of these were in 2 subgroups: "treatment responders" (n = 43) from all 4 groups in the acute trial, seen monthly for 24 weeks, and "placebo nonresponders" (n = 41), treated with open-label ATX for 10 weeks. Participants originally assigned to PT continued PT during the extension; the remainder served as controls. Primary outcome measurements were the parent-rated Swanson, Nolan and Pelham ADHD scale and the Home Situations Questionnaire.Sixty percent (26 of 43) of treatment responders in the acute trial, including 68% of responders originally assigned to ATX, still met the response criteria at the end of the extension. The response rate of placebo nonresponders treated with 10-week open-label ATX was 37% (15 of 41), similar to the acute trial. Children receiving open-label ATX + PT were significantly more likely to be ADHD responders (53% versus 23%) and noncompliance responders (58% versus 14%) than those receiving open-label ATX alone.Most ATX responders maintained their responses during the extension. PT combined with ATX in the open-label trial appeared to improve ADHD and noncompliance outcomes more than ATX alone. Clinical trial registration information-Atomoxetine, Placebo and Parent Management Training in Autism (Strattera); http://clinicaltrials.gov; NCT00844753.