Amifampridine safety and efficacy in spinal muscular atrophy ambulatory patients: a randomized, placebo-controlled, crossover phase 2 trial.

BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal recessive disease where a deficient amount of SMN protein leads to progressive lower motor neuron degeneration. SMN-enhancing therapies are now available. Yet, fatigue and signs of impaired neuromuscular junction (NMJ) transmission could contribute to SMA phenotype. Amifampridine prolongs presynaptic NMJ terminal depolarization, enhancing neuromuscular transmission. METHODS: SMA-001 was a phase 2, 1:1 randomized, double-blind, placebo-controlled crossover study. Ambulatory (walking unaided at least 30 m) SMA Type 3 patients, untreated with SMN-enhancing medications, entered a run-in phase where amifampridine was titrated up to an optimized stable dose. Patients achieving at least three points improvement in Hammersmith Functional Motor Score Expanded (HFMSE) were randomized to amifampridine or placebo, alternatively, in the 28-day double-blind crossover phase. Safety was evaluated by adverse events (AE) collection. Primary efficacy measure was the HFMSE change from randomization. Secondary outcomes included timed tests and quality of life assessment. Descriptive analyses and a mixed effects linear model were used for statistics. RESULTS: From 14 January 2019, 13 patients, mean age 34.5 years (range 18-53), with 5/13 (38.5%) females, were included. No serious AE were reported. Transient paresthesia (33.3%) was the only amifampridine-related AE. Six patients for each treatment sequence were randomized. Amifampridine treatment led to a statistically significant improvement in HFMSE (mean difference 0.792; 95% CI from 0.22 to 1.37; p = 0.0083), compared to placebo, but not in secondary outcomes. DISCUSSION: SMA-001 study provided Class II evidence that amifampridine was safe and effective in treating ambulatory SMA type 3 patients. CLINICAL TRIAL REGISTRATION: NCT03781479; EUDRACT 2017-004,600-22.

Therapeutic efficacy of 3,4-Diaminopyridine phosphate on neuromuscular junction in Pompe disease.

3,4-Diaminopyridine (3,4-DAP) and its phosphate form, 3,4-DAPP have been used efficiently in the past years to treat muscular weakness in myasthenic syndromes with neuromuscular junctions (NMJs) impairment. Pompe disease (PD), an autosomal recessive metabolic disorder due to a defect of the lysosomal enzyme α-glucosidase (GAA), presents some secondary symptoms that are related to neuromuscular transmission dysfunction, resulting in endurance and strength failure. In order to evaluate whether 3,4-DAPP could have a beneficial effect on this pathology, we took advantage of a transient zebrafish PD model that we previously generated and characterized. We investigated presynaptic and postsynaptic structures, NMJs at the electron microscopy level, and zebrafish behavior, before and after treatment with 3,4-DAPP. After drug administration, we observed an increase in the number of acetylcholine receptors an increment in the percentage of NMJs with normal structure and amelioration in embryo behavior, with recovery of typical movements that were lost in the embryo PD model. Our results revealed early NMJ impairment in Pompe zebrafish model with improvement after administration of 3,4-DAPP, suggesting its potential use as symptomatic drug in patients with Pompe disease.

Two-Dimensional Proton Magnetic Resonance Spectroscopy versus J-Editing for GABA Quantification in Human Brain: Insights from a GABA-Aminotransferase Inhibitor Study.

Metabolite-specific, scalar spin-spin coupling constant (J)-editing 1H MRS methods have become gold-standard for measuring brain γ-amino butyric acid (GABA) levels in human brain. Localized, two-dimensional (2D) 1H MRS technology offers an attractive alternative as it significantly alleviates the problem of severe metabolite signal overlap associated with standard 1D MRS and retains spectroscopic information for all MRS-detectable species. However, for metabolites found at low concentration, a direct, in vivo, comprehensive methods comparison is challenging and has not been reported to date. Here, we document an assessment of comparability between 2D 1H MRS and J-editing methods for measuring GABA in human brain. This clinical study is unique in that it involved chronic administration a GABA-amino transferase (AT) inhibitor (CPP-115), which induces substantial increases in brain GABA concentration, with normalization after washout. We report a qualitative and quantitative comparison between these two measurement techniques. In general, GABA concentration changes detected using J-editing were closely mirrored by the 2D 1H MRS time courses. The data presented are particularly encouraging considering recent 2D 1H MRS methodological advances are continuing to improve temporal resolution and spatial coverage for achieving whole-brain, multi-metabolite mapping.

In Vivo Detection of CPP-115 Target Engagement in Human Brain.

CPP-115, a next-generation γ-amino butyric acid (GABA)-aminotransferase (AT) inhibitor, shows comparable pharmacokinetics, improved safety and tolerability, and a more favorable toxicity profile when compared with vigabatrin. The pharmacodynamic characteristics of CPP-115 remain to be evaluated. The present study employed state-of-the-art proton magnetic resonance spectroscopy techniques to measure changes in brain GABA+ (the composite resonance of GABA, homocarnosine, and macromolecules) concentrations in healthy subjects receiving oral daily doses of CPP-115 or placebo. Six healthy adult males were randomized to receive either single daily 80 mg doses of CPP-115 (n=4) or placebo (n=2) for 6, 10, or 14 days. Metabolite-edited spectra and two-dimensional J-resolved spectroscopy data were acquired from the parietal-occipital cortex and supplementary motor area in all subjects. Four scans were performed in each subject that included a predrug baseline measure, two scans during the dosing timeframe, and a final scan that occurred 1 week after drug cessation. CPP-115 induced robust and significant increases in brain GABA+ concentrations that ranged between 52 and 141% higher than baseline values. Elevated GABA+ concentrations returned to baseline values following drug clearance. Subjects receiving placebo showed no significant changes in GABA+ concentration. CPP-115-induced changes were exclusive to GABA and homocarnosine, and CPP-115 afforded brain GABA+ concentration changes comparable to or greater than previous vigabatrin spectroscopy studies in healthy epilepsy-naive subjects. The return to baseline GABA+ concentration indicates the reversible GABA-AT resynthesis following drug washout. These preliminary data warrant further spectroscopy studies that characterize the acute pharmacodynamic effects of CPP-115 with additional dose-descending measures.

Acetylator Status Impacts Amifampridine Phosphate (Firdapse™) Pharmacokinetics and Exposure to a Greater Extent Than Renal Function.

PURPOSE: The purpose of this study is to evaluate safety, tolerability, and pharmacokinetic (PK) properties of amifampridine phosphate (Firdapse™) and its major inactive 3-N-acetyl metabolite in renally impaired and healthy individuals with slow acetylator (SA) and rapid acetylator (RA) phenotypes. METHODS: This was a Phase I, multicenter, open-label study of the PK properties and safety profile of amifampridine phosphate in individuals with normal, mild, moderate, or severely impaired renal function. Amifampridine phosphate was given as a single 10 mg (base equivalent) dose, and the plasma and urine PK properties of amifampridine and its 3-N-acetyl metabolite were determined. The safety profile was evaluated by monitoring adverse events (AEs), clinical laboratory tests, and physical examinations. FINDINGS: Amifampridine clearance was predominantly metabolic through N-acetylation, regardless of renal function in both acetylator phenotypes. In individuals with normal renal function, mean renal clearance represented approximately 3% and 18% of the total clearance of amifampridine in RA and SA, respectively. Large differences in amifampridine exposure were observed between acetylation phenotypes across renal function levels. Mean amifampridine exposure values of AUC0-∞ and Cmax were up to 8.8-fold higher in the SA group compared with the RA group across renal function levels. By comparison, mean AUC0-∞ was less affected by renal function within an acetylator group, only 2- to 3-fold higher in individuals with severe renal impairment (RI) compared with those with normal renal function. Exposure to amifampridine in the SA group with normal renal function was higher (AUC0-∞, approximately 1.8-fold; Cmax, approximately 4.1-fold) than the RA group with severe RI. Exposure to the inactive 3-N-acetyl metabolite was higher than amifampridine in both acetylator groups, independent of renal function level. The metabolite is cleared by renal excretion, and exposure was clearly dependent on renal function with 4.0- to 6.8-fold increases in AUC0-∞ from normal to severe RI. No new tolerability findings were observed. IMPLICATIONS: A single dose of 10 mg of amifampridine phosphate was well tolerated, independent of renal function and acetylator status. The results indicate that the PK profile of amifampridine is affected by metabolic acetylator phenotype to a greater extent than by renal function level, supporting Firdapse™ administration in individuals with RI in line with current labeling recommendations. Amifampridine should be dosed to effect per the individual patient need, altering administration frequency and dose in normal through severe RI. The therapeutic dose of amifampridine phosphate should be tailored to the individual patient needs by gradual dose titration up to the present maximum recommended dose (60-80 mg/day) or until dose-limiting AEs intervene to avoid overdosing and underdosing. EudraCT identifier: 2013-005349-35.

Efficacy and safety of aripiprazole vs. haloperidol for long-term maintenance treatment following acute relapse of schizophrenia.

Aripiprazole is a novel atypical antipsychotic for the treatment of schizophrenia. It is a D2 receptor partial agonist with partial agonist activity at 5-HT1A receptors and antagonist activity at 5-HT2A receptors. The long-term efficacy and safety of aripiprazole (30 mg/d) relative to haloperidol (10 mg/d) were investigated in two 52-wk, randomized, double-blind, multicentre studies (using similar protocols which were prospectively identified to be pooled for analysis) in 1294 patients in acute relapse with a diagnosis of chronic schizophrenia and who had previously responded to antipsychotic medications. Aripiprazole demonstrated long-term efficacy that was comparable or superior to haloperidol across all symptoms measures, including significantly greater improvements for PANSS negative subscale scores and MADRS total score (p<0.05). The time to discontinuation for any reason was significantly greater with aripiprazole than with haloperidol (p=0.0001). Time to discontinuation due to adverse events or lack of efficacy was significantly greater with aripiprazole than with haloperidol (p=0.0001). Aripiprazole was associated with significantly lower scores on all extrapyramidal symptoms assessments than haloperidol (p<0.001). In summary, aripiprazole demonstrated efficacy equivalent or superior to haloperidol with associated benefits for safety and tolerability. Aripiprazole represents a promising new option for the long-term treatment of schizophrenia.

Aripiprazole for the prevention of relapse in stabilized patients with chronic schizophrenia: a placebo-controlled 26-week study.

BACKGROUND: Aripiprazole is a novel antipsychotic for the management of schizophrenia. This study investigated the efficacy, safety, and tolerability of aripiprazole in preventing relapse in adult chronic schizophrenia patients experiencing ongoing stable symptomatology. METHOD: In this 26-week, randomized, double-blind, placebo-controlled, parallel-group, multi-center study, 310 patients with DSM-IV schizophrenia (mean Positive and Negative Syndrome Scale [PANSS] total score = 82) were randomly assigned to receive a once-daily fixed dose of aripiprazole, 15 mg, or placebo. The primary outcome measure was time to relapse following randomization. Secondary objectives were to assess the efficacy, safety, and tolerability of aripiprazole, 15 mg, compared with placebo, in the study population. The study was conducted between Dec. 21, 2000, and Aug. 20, 2001. RESULTS: The time to relapse following randomization was significantly (p < .001) longer for aripiprazole compared with placebo. More patients relapsed with placebo (N = 85; 57%) than aripiprazole (N = 50; 34%); the relative risk of relapse for the aripiprazole group was 0.59 (p < .001). Aripiprazole was significantly superior to placebo from baseline to endpoint in PANSS total, PANSS positive, PANSS-derived Brief Psychiatric Rating Scale, and Clinical Global Impressions-Severity of Illness scale (CGI-S) scores and demonstrated significantly better mean Clinical Global Impressions-Global Improvement scale scores (p < or = .01 for all comparisons except CGI-S: .01 < p < or = .05). Aripiprazole was well tolerated, with no evidence of marked sedation and no evidence of hyperprolactinemia or prolonged heart rate-corrected QT interval (QTc). Extrapyramidal symptoms were comparable in the aripiprazole and placebo groups. Modest mean weight loss at endpoint was evident in both groups. CONCLUSION: Aripiprazole, 15 mg once daily, is an effective, well-tolerated treatment for prevention of relapse in patients with chronic, stable schizophrenia.

A placebo-controlled, double-blind study of the efficacy and safety of aripiprazole in patients with acute bipolar mania.

OBJECTIVE: The authors compared the efficacy and safety of aripiprazole, a novel antipsychotic, to placebo for treatment of patients in an acute manic or mixed episode of bipolar disorder. METHOD: This 3-week, multicenter, double-blind study randomly assigned 262 bipolar disorder patients in an acute manic or mixed episode to aripiprazole, 30 mg/day (reduced to 15 mg/day if needed for tolerability), or placebo. Patients remained hospitalized for at least 2 of the weeks. The primary efficacy measure was mean change from baseline in total score on the Young Mania Rating Scale; response was defined as a decrease in score of > or =50%. RESULTS: Aripiprazole produced statistically significant mean improvements in total score on the Young Mania Rating Scale compared with placebo (-8.2 versus -3.4, respectively) and produced a significantly higher response rate (40% versus 19%). For key efficacy variables (response per Young Mania Rating Scale; Clinical Global Impression-Bipolar Version scores for severity of illness [mania] and change from preceding phase [mania]), aripiprazole separated from placebo by day 4. The completion rate was significantly higher with aripiprazole than with placebo (42% versus 21%). Discontinuations due to adverse events did not differ significantly between the aripiprazole and placebo groups. There were no significant changes in body weight versus placebo, and aripiprazole was not associated with elevated serum prolactin or QTc prolongation. CONCLUSIONS: Aripiprazole had significantly greater efficacy than placebo for the treatment of bipolar disorder patients in acute manic or mixed episodes and was safe and well tolerated in this randomized controlled trial.

Aripiprazole, an antipsychotic with a novel mechanism of action, and risperidone vs placebo in patients with schizophrenia and schizoaffective disorder.

BACKGROUND: Aripiprazole is a dopamine D2 receptor partial agonist with partial agonist activity at serotonin 5HT1A receptors and antagonist activity at 5HT2A receptors. This multicenter trial examined the efficacy, safety, and tolerability of aripiprazole in patients with acute exacerbation of schizophrenia or schizoaffective disorder. METHODS: In this 4-week double-blind study, 404 patients were randomized to 20 mg/d (n = 101) or 30 mg/d (n = 101) of aripiprazole, placebo (n = 103), or 6 mg/d of risperidone (n = 99). Efficacy assessments included Positive and Negative Syndrome Scale (PANSS) scores and Clinical Global Impression scores. Safety and tolerability evaluations included extrapyramidal symptoms and effects on weight, prolactin, and corrected QT (QTc) interval. RESULTS: Aripiprazole (20 and 30 mg/d) and risperidone (6 mg/d) were significantly better than placebo on all efficacy measures. Separation from placebo occurred at week 1 for PANSS total and positive scores with aripiprazole and risperidone and for PANSS negative scores with aripiprazole. There were no significant differences between aripiprazole and placebo in mean change from baseline in the extrapyramidal symptom rating scales. Mean prolactin levels decreased with aripiprazole but significantly increased 5-fold with risperidone. Mean change in QTc interval did not differ significantly from placebo with any active treatment group. Aripiprazole and risperidone groups showed a similar low incidence of clinically significant weight gain. CONCLUSIONS: Aripiprazole is effective, safe, and well tolerated for the positive and negative symptoms in schizophrenia and schizoaffective disorder. It is the first non-D2 receptor antagonist with clear antipsychotic effects and represents a novel treatment development for psychotic disorders.

Switching patients to aripiprazole from other antipsychotic agents: a multicenter randomized study.

RATIONALE: Switching patients from one antipsychotic to another can lead to tolerability problems or transient symptom exacerbations. It is important to compare switching strategies to determine which methods produce the best possible patient outcomes. OBJECTIVE: To investigate the efficacy, safety and tolerability of three dosing strategies for switching chronic, stable patients with schizophrenia from current oral antipsychotic monotherapy to once-daily oral aripiprazole monotherapy. METHOD: Patients in this 8-week, open-label, outpatient study were randomized to: 1). immediate initiation of 30 mg/day aripiprazole with simultaneous immediate discontinuation of current antipsychotic; 2). immediate initiation of 30 mg/day aripiprazole while tapering off current antipsychotic over 2 weeks; or 3). up-titrating aripiprazole to 30 mg/day over 2 weeks, while simultaneously tapering off current antipsychotic. Efficacy assessments included PANSS, CGI-S, and CGI-I scores. Safety assessments included: adverse events (AEs) recording, evaluation of extrapyramidal symptoms (EPS), vital signs, ECG, and clinical laboratory tests. RESULTS: Efficacy with aripiprazole was maintained during the study with numerical improvements compared with baseline in all three groups. The overall incidence of AEs was broadly comparable across all groups, and AEs were generally mild to moderate in severity and time-limited. Discontinuations due to AEs were comparable across the groups. No deterioration in EPS occurred in any group. The reduction in body weight and plasma prolactin levels following switch to aripiprazole were comparable across the three groups. CONCLUSION: Any of the three strategies evaluated can be used safely for switching patients to aripiprazole from antipsychotic monotherapy. Furthermore, patients' symptoms may continue to improve after switching to aripiprazole.

Efficacy and safety of aripiprazole and haloperidol versus placebo in patients with schizophrenia and schizoaffective disorder.

BACKGROUND: Aripiprazole is an investigational agent for treating schizophrenia that has a novel pharmacologic profile. The present study investigated the efficacy, safety, and tolerability of aripiprazole and haloperidol compared with placebo. METHOD: A 4-week, double-blind, randomized study, conducted at 36 U.S. centers between July 1997 and June 1998, compared aripiprazole (15 mg/day, 30 mg/day) to placebo, with haloperidol (10 mg/day) as an active control. Fixed doses of each agent were administered from day 1 throughout the study. A total of 414 patients with a primary DSM-IV diagnosis of schizophrenia or schizoaffective disorder were randomized. Efficacy measures included the Positive and Negative Syndrome Scale (PANSS) total, PANSS positive, PANSS negative, PANSS-derived Brief Psychiatric Rating Scale (BPRS) core, Clinical Global Impressions (CGI)-Severity of Illness, and mean CGI-Improvement scores. Safety and tolerability evaluations included extrapyramidal symptoms (EPS), weight gain, serum prolactin level, and QTc interval. RESULTS: Both doses of aripiprazole and haloperidol, 10 mg, produced statistically significant (p < or = .05) improvements from baseline in PANSS total, PANSS positive, PANSS-derived BPRS core, and CGI-Severity scores and significantly lower CGI-Improvement scores at endpoint, compared with placebo. Aripiprazole, 15 mg, and haloperidol, 10 mg, significantly improved PANSS negative score compared with placebo. Both aripiprazole doses and haloperidol separated from placebo for PANSS total scores at week 2. Unlike haloperidol, aripiprazole was not associated with significant EPS or prolactin elevation at endpoint compared with placebo. There were no statistically significant differences in mean changes in body weight across the treatment groups versus placebo, and no patients receiving aripiprazole experienced clinically significant increases in QTc interval. CONCLUSION: Aripiprazole, effective against positive and negative symptoms, is a safe and well-tolerated potential treatment for schizophrenia and schizoaffective disorder.