Dyskinesia matters

Levodopa-induced dyskinesia (LID) represents a significant source of discomfort for people with Parkinson's disease (PD). It negatively affects quality of life, it is associated with both motor and nonmotor fluctuations, and it brings an increased risk of disability, balance problems, and falls. Although the prevalence of severe LID appears to be lower than in previous eras (likely owing to a more conservative use of oral levodopa), we have not yet found a way to prevent the development of this complication. Advanced surgical therapies, such as deep brain stimulation, ameliorate LID, but only a minority of PD patients qualify for these interventions. Although some have argued that PD patients would rather be ON with dyskinesia than OFF, the deeper truth is that patients would very much prefer to be ON without dyskinesia. As researchers and clinicians, we should aspire to make that goal a reality. To this end, translational research on LID is to be encouraged and persistently pursued. © 2019 International Parkinson and Movement Disorder Society.

Higher neuron densities in the cerebral cortex and larger cerebellums may limit dive times of delphinids compared to deep-diving toothed whales

Since the work of Tower in the 1950s, we have come to expect lower neuron density in the cerebral cortex of larger brains. We studied dolphin brains varying from 783 to 6215g. As expected, average neuron density in four areas of cortex decreased from the smallest to the largest brain. Despite having a lower neuron density than smaller dolphins, the killer whale has more gray matter and more cortical neurons than any mammal, including humans. To begin a study of non-dolphin toothed whales, we measured a 596g brain of a pygmy sperm whale and a 2004g brain of a Cuvier's beaked whale. We compared neuron density of Nissl stained cortex of these two brains with those of the dolphins. Non-dolphin brains had lower neuron densities compared to all of the dolphins, even the 6215g brain. The beaked whale and pygmy sperm whale we studied dive deeper and for much longer periods than the dolphins. For example, the beaked whale may dive for more than an hour, and the pygmy sperm whale more than a half hour. In contrast, the dolphins we studied limit dives to five or 10 minutes. Brain metabolism may be one feature limiting dolphin dives. The brain consumes an oversized share of oxygen available to the body. The most oxygen is used by the cortex and cerebellar gray matter. The dolphins have larger brains, larger cerebellums, and greater numbers of cortex neurons than would be expected given their body size. Smaller brains, smaller cerebellums and fewer cortical neurons potentially allow the beaked whale and pygmy sperm whale to dive longer and deeper than the dolphins. Although more gray matter, more neurons, and a larger cerebellum may limit dolphins to shorter, shallower dives, these features must give them some advantage. For example, they may be able to catch more elusive individual high-calorie prey in the upper ocean.

Long-term safety and efficacy of deutetrabenazine for the treatment of tardive dyskinesia

OBJECTIVE

To evaluate the long-term safety and efficacy of deutetrabenazine in patients with tardive dyskinesia (TD).

METHOD

Patients with TD who completed the 12 week, phase 3, placebo-controlled trials were eligible to enter this open-label, single-arm study. The open-label study consisted of a 6 week dose-escalation phase and a long-term maintenance phase (clinic visits at Weeks 4, 6 and 15, and every 13 weeks until Week 106). Patients began deutetrabenazine at 12 mg/day, titrating up to a dose that was tolerable and provided adequate dyskinesia control, based on investigator judgement, with a maximum allowed dose of 48 mg/day (36 mg/day for patients taking strong cytochrome P450 2D6 (CYP2D6) inhibitors). Safety measures included incidence of adverse events (AEs) and scales used to monitor parkinsonism, akathisia/restlessness, anxiety, depression, suicidality and somnolence/sedation. Efficacy endpoints included the change in Abnormal Involuntary Movement Scale (AIMS) score (items 1 to 7) from baseline and the proportion of patients rated as 'Much Improved' or 'Very Much Improved' on the Clinical Global Impression of Change.

RESULTS

A total of 343 patients enrolled in the extension study, and there were 331 patient-years of exposure in this analysis. The exposure-adjusted incidence rates of AEs with long-term treatment were comparable to or lower than those observed in the phase 3 trials. The mean (SE) change in AIMS score was -4.9 (0.4) at Week 54 (n = 146), - 6.3 (0.7) at Week 80 (n = 66) and -5.1 (2.0) at Week 106 (n = 8).

CONCLUSIONS

Overall, long-term treatment with deutetrabenazine was efficacious, safe, and well tolerated in patients with TD.

TRIAL REGISTRATION NUMBER

NCT02198794.

Targeting neurons in the gastrointestinal tract to treat Parkinson's disease

Background

Parkinson's disease (PD) is associated with α-synuclein (αS) aggregation within the enteric nervous system (ENS) and constipation. Squalamine displaces proteins that are electrostatically bound to intracellular membranes and through this mechanism suppresses aggregation of αS monomers into neurotoxic oligomers.

Objective

We sought to evaluate the safety of ENT-01 oral tablets (a synthetic squalamine salt), its pharmacokinetics, and its effect on bowel function in PD patients with constipation.

Methods

In Stage 1, 10 patients received escalating single doses from 25 to 200 mg/day or maximum tolerated dose (MTD). In Stage 2, 34 patients received daily doses escalating from 75 to a maximum of 250 mg/day, a dose that induced change in bowel function or MTD, followed by a fixed dose for 7 days, and a 2-week washout. Primary efficacy endpoint was defined as an increase of 1 complete spontaneous bowel movement (CSBM)/week, or 3 CSBM/week over the baseline period, as defined by FDA guidelines for prokinetic agents. Safety was also assessed.

Results

Over 80% of patients achieved the primary efficacy endpoint, with the mean number of CSBM/week increasing from 1.2 at baseline to 3.6 during fixed dosing (p = 1.2 × 10⁻⁷). Common adverse events included nausea in 21/44 (47%) and diarrhea in 18/44 (40%) patients. Systemic absorption was <0.3%.

Conclusions

Orally administered ENT-01 was safe and significantly improved bowel function in PD, suggesting that the ENS is not irreversibly damaged in PD. Minimal systemic absorption suggests that improvements result from local stimulation of the ENS. A double-blind, placebo-controlled study is now ongoing.

Impact of non-motor symptoms in Parkinson's disease: a PMDAlliance survey

PURPOSE

Parkinson's disease (PD) is associated with non-motor symptoms (NMS) that can cause progressive disability and impact quality of life of people with PD (PwP) and increase burden on care partners. This survey was designed to evaluate the prevalence, impact, and educational preferences regarding NMS on PwP and their care partners.

PATIENTS AND METHODS

A 17-question survey was sent to the total membership of PMDAlliance, a nonprofit organization reaching 3,685 households of PwP. Care partners and other interested individuals could also respond. The survey was conducted using Survey Monkey, an online survey platform, and included distinct questions for respondents with and without NMS.

RESULTS

A total of 700 individuals responded to the survey. Of the respondents, 378 (54%) were care partners and 287 (41%) were PwP. About 90% of the respondents reported having experience with NMS in PwP, including sleep problems (84%), cognitive symptoms (76%), anxiety (65%), depression (56%), hallucinations (40%), and delusions (23%). NMS in PwP were reported by more care partners (97%) than PwP (80%). NMS had at least some impact on quality of life for 84% of the respondents; 48% indicated that NMS represented a greater challenge than motor symptoms. Care partners were more likely than PwP to report that NMS were more challenging than motor symptoms (58% vs 32%). Respondents with and without NMS indicated a desire for NMS education.

CONCLUSION

This survey underscores the significant impact of NMS on the quality of life of PwP and highlights the need for improved recognition and education about its effects.

Integrated Analysis of Droxidopa for the Treatment of Neurogenic Orthostatic Hypotension in Patients with Parkinson Disease

Introduction

Neurogenic orthostatic hypotension (nOH) is associated with neurodegenerative conditions, may cause symptoms of end-organ hypoperfusion, increases fall risk, and can negatively impact quality of life. Droxidopa is approved for the treatment of symptomatic nOH in adults. As the largest subpopulation of patients with nOH has a diagnosis of Parkinson disease (PD), the efficacy and tolerability of droxidopa in patients with PD and nOH were examined using integrated clinical trial data.

Methods

Post hoc analyses included data from the phase 3, randomized, placebo-controlled clinical trials of droxidopa (two short-term [1-2 weeks] trials and one medium-term [8-10 weeks] trial) in the subset of participants with PD and symptomatic nOH. Efficacy was assessed using standing blood pressure (BP) measurements and the Orthostatic Hypotension Questionnaire (OHQ), a patient-reported evaluation of nOH symptoms (Orthostatic Hypotension Symptom Assessment [OHSA]), and their impact (Orthostatic Hypotension Daily Activity Scale [OHDAS]).

Results

The analysis included 307 patients with PD (droxidopa, n = 150; placebo, n = 157). Compared with placebo, droxidopa significantly improved the OHQ composite score (P = 0.014), the OHSA composite score (P = 0.022), and the OHDAS composite score (P = 0.029) from baseline to end of study/week one. We found significant increases in standing mean systolic/diastolic BP for droxidopa versus placebo (P = 0.003/0.002). Adverse event (AE) rates were qualitatively similar between groups; the most frequently reported AEs in the droxidopa groups included headache, dizziness, nausea, and hypertension.

Conclusions

These post hoc analyses suggest that droxidopa provides meaningful clinical benefits and is well tolerated in the treatment of symptomatic nOH in patients with PD.

Therapeutic strategies for Parkinson disease: beyond dopaminergic drugs

Existing therapeutic strategies for managing Parkinson disease (PD), which focus on addressing the loss of dopamine and dopaminergic function linked with degeneration of dopaminergic neurons, are limited by side effects and lack of long-term efficacy. In recent decades, research into PD pathophysiology and pharmacology has focused on understanding and tackling the neurodegenerative processes and symptomology of PD. In this Review, we discuss the challenges associated with the development of novel therapies for PD, highlighting emerging agents that aim to target cell death, as well as new targets offering a symptomatic approach to managing features and progression of the disease.

Standing and Supine Blood Pressure Outcomes Associated With Droxidopa and Midodrine in Patients With Neurogenic Orthostatic Hypotension: A Bayesian Meta-analysis and Mixed Treatment Comparison of Randomized Trials

BACKGROUND

The comparative effects of droxidopa and midodrine on standing systolic blood pressure (sSBP) and risk of supine hypertension in patients with neurogenic orthostatic hypotension (NOH) are unknown.

OBJECTIVE

To perform a Bayesian mixed-treatment comparison meta-analysis of droxidopa and midodrine in the treatment of NOH.

METHODS

The PubMed, CENTRAL, and EMBASE databases were searched up to November 16, 2016. Study selection consisted of randomized trials comparing droxidopa or midodrine with placebo and reporting on changes in sSBP and supine hypertension events. Data were pooled to perform a comparison among interventions in a Bayesian fixed-effects model using vague priors and Markov chain Monte Carlo simulation with Gibbs sampling, calculating pooled mean changes in sSBP and risk ratios (RRs) for supine hypertension with associated 95% credible intervals (CrIs).

RESULTS

Six studies (4 administering droxidopa and 2 administering midodrine) enrolling a total of 783 patients were included for analysis. The mean change from baseline in sSBP was significantly greater for both drugs when compared with placebo (droxidopa 6.2 mm Hg [95% CrI = 2.4-10] and midodrine 17 mm Hg [95% CrI = 11.4-23]). Comparative analysis revealed a significant credible difference between droxidopa and midodrine. The RR for supine hypertension was significantly greater for midodrine, but not droxidopa, when compared with placebo (droxidopa RR = 1.4 [95% CrI = 0.7-2.7] and midodrine RR = 5.1 [95% CrI = 1.6-24]). Conclusion and Relevance: In patients with NOH, both droxidopa and midodrine significantly increase sSBP, the latter to a greater extent. However, midodrine, but not droxidopa, significantly increases risk of supine hypertension.

ADS-5102 (Amantadine) Extended-Release Capsules for Levodopa-Induced Dyskinesia in Parkinson's Disease (EASE LID 2 Study): Interim Results of an Open-Label Safety Study

Background:

Medical treatment of levodopa-induced dyskinesia (LID) in Parkinson’s disease (PD) is an unmet need. ADS-5102 (amantadine) extended-release capsules is being developed for the treatment of LID in patients with PD.

Objective:

Evaluate the long-term safety and tolerability of 274 mg ADS-5102 for LID in PD.

Methods:

In an ongoing, open-label safety study (NCT02202551), PD patients with LID received 274 mg of ADS-5102 once daily at bedtime. Patients were recruited from previous ADS-5102 trials. In addition, patients were enrolled who were ineligible for previous ADS-5102 trials due to previous implantation of deep-brain stimulation (DBS) devices. The primary outcome measure was safety assessed through adverse events (AEs). Efficacy was assessed using the Movement Disorder Society–Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), Part IV and its subparts.

Results:

For this interim analysis, 223 patients received ADS-5102 for a mean duration of 348 (SD 182) days. The most common AEs included falls (25.1%), visual hallucinations (19.3%), peripheral edema (13.0%), and constipation (12.6%). Overall, 32 patients (14.3%) discontinued due to an AE. In patients receiving placebo in previous studies, the mean MDS-UPDRS, Part IV scores decreased by 3.4 points from baseline (n = 78) to week 8 and remained stable through week 64 (n = 21). In patients receiving ADS-5102 in previous studies, the mean baseline (n = 61) MDS-UPDRS, Part IV score was low due to the response to ADS-5102 in previous studies and remained stable through week 64 (total of 88 weeks; n = 21). The effect was primarily due to reduction in item 4.2 (functional impact of dyskinesia) and item 4.4 (functional impact of motor fluctuations).

Conclusions:

ADS-5102 was generally well tolerated in all groups, including DBS patients, and the safety profile was consistent with previous controlled studies. Long-term durability and tolerability were shown from the double-blind studies through participation in the open-label study up to 88 weeks.

Tardive dyskinesia: Out of the shadows

The approvals of the first two medications, valbenazine and deutetrabenazine, to treat tardive dyskinesia have ushered in a new era in neuropsychiatric care. Tardive syndromes are defined as delayed onset, persistent movement disorders or sensory phenomena that occur in association with exposure to dopamine receptor blocking agents (DRBAs). Their underlying pathophysiology remains to be fully elucidated, but clinicians can conceptualize tardive syndromes as persistent dopamine supersensitivity states. Tardive syndromes can potentially cause distress, disfigurement, embarrassment, and dysfunction, and are often permanent. Therefore, practitioners who prescribe DRBAs should be aware of this potential, carefully assess the risk/benefit ratio when considering the use of these medications, and be sure that patients are appropriately informed. Patients on DRBAs should be monitored for the development of tardive syndromes, including through the use of regularly scheduled Abnormal Involuntary Movement Scale (AIMS) (or similar) examinations. Clinicians prescribing DRBAs should be familiar with the diagnosis and management of tardive syndromes, and be able to institute treatment or refer patients when treatment is appropriate. Future research may focus on the potential benefit of earlier introduction of VMAT2 inhibitors to delay onset or progression of tardive syndromes. More effective treatments are still needed, as are effective, well-tolerated antipsychotics that do not cause tardive syndromes.

A 500 U/2 mL dilution of abobotulinumtoxinA vs. placebo: randomized study in cervical dystonia

Purpose/aim: AbobotulinumtoxinA (Dysport®, Ipsen Biopharmaceuticals, Inc., Basking Ridge, NJ, USA) is an acetylcholine release inhibitor and a neuromuscular blocking agent. The United States prescribing information for abobotulinumtoxinA previously indicated only one dilution for cervical dystonia: 500 U/1 mL. Clinical trial data supporting a larger volume with a 500 U/2 mL dilution would offer clinicians flexibility with injection volume to better meet patient needs.

MATERIALS AND METHODS

We conducted a 12-week, phase 3b, multicenter, randomized, double-blind, placebo-controlled trial (NCT01753310). Adult subjects with a primary diagnosis of cervical dystonia were randomized (2:1) to receive a single injection of either abobotulinumtoxinA, 500 U/2 mL dilution, or placebo. The primary efficacy endpoint was changed from baseline in Toronto Western Spasmodic Torticollis Rating Scale total score at Week 4.

RESULTS

A total of 134 subjects (abobotulinumtoxinA, n = 89; placebo, n = 45) were randomized (intent-to-treat population) and 129 (abobotulinumtoxinA, n = 84; placebo, n = 45) completed the Week 4 primary endpoint evaluation (modified intent-to-treat population). In the modified intent-to-treat population, subjects receiving abobotulinumtoxinA experienced significantly greater changes from baseline versus placebo on the primary endpoint (weighted overall treatment difference -8.3, P < 0.001). The most common treatment-emergent adverse events (TEAEs) were dysphagia, muscle weakness, neck pain and headache. Overall, TEAEs were consistent with those reported in the abobotulinumtoxinA prescribing information (1 mL dilution) for cervical dystonia patients.

CONCLUSIONS

This trial provides evidence that a 500 U/2 mL dilution is an effective treatment for cervical dystonia and exhibits a safety profile consistent with the known safety profile of abobotulinumtoxinA.

Onset and duration of effect of extended-release carbidopa-levodopa in advanced Parkinson's disease

BACKGROUND

In patients with Parkinson's disease (PD), oral dosing of extended-release carbidopa-levodopa (Rytary, IPX066 [ER CD-LD]) achieves peak levodopa plasma concentrations within 1 hour and maintains them for 4-6 hours.

AIMS

To compare the onset and duration of ER CD-LD benefit with those of immediate-release carbidopa-levodopa (IR CD-LD) in PD patients with motor fluctuations, using crossover data, and to evaluate which threshold values of improvement in finger-tapping and Unified Parkinson's Disease Rating Scale (UPDRS) motor scores yield results most similar to those for trained raters' "on"/"off" assessments.

METHODS

Patients underwent serial "on"/"off" rating and provided serial finger-tapping and UPDRS motor scores after receiving, in an "off" state, their usual morning IR dose or an ER dose designed to produce a similar levodopa peak concentration. Predefined improvement thresholds for analysis were 10%, 15%, and 20% increases in finger-tapping score and 2.5, 5, 7, and 11-point decreases in UPDRS motor score. Serial plasma samples were assayed for levodopa.

RESULTS

Among 27 patients, mean time to onset of an "on" state was similar for ER compared with IR CD-LD (0.83 vs 0.81 hour), but mean duration was significantly longer for ER CD-LD than for IR CD-LD (5.56 vs 2.69 hours; P<0.0001). Duration was best matched by a $20% improvement in finger-tapping, a $11-point improvement in UPDRS motor score, and a levodopa plasma concentration $1,000 ng/mL.

CONCLUSION

For ER CD-LD, observer assessments of "on" state were corroborated by sustained treatment effects. Correlations among "on"-state duration, finger-tapping score, and UPDRS motor score may suggest clinically relevant thresholds for acute assessment of treatment benefit.

Long-term effects of rasagiline and the natural history of treated Parkinson's disease

BACKGROUND

The Attenuation of Disease progression with Azilect GIven Once-daily (ADAGIO) delayed-start study demonstrated a benefit of early-start treatment with rasagiline 1 mg/day versus delayed-start treatment in PD. This follow-up study aimed to assess whether these benefits persist and the clinical progression rate during long-term naturalistic treatment.

METHODS

The ADAGIO Follow-Up study was initiated approximately 26 months after completion of the ADAGIO study. Patients were followed for 3 years and were treated in an open-label manner with rasagiline 1 mg/day and any other PD treatment that was deemed appropriate. Changes from follow-up baseline to study end in UPDRS scores, and the emergence of clinical milestones (including unsteady gait and/or balance impairment, falls, freezing of gait, and cognitive decline) were assessed.

RESULTS

The study enrolled 683 patients (58% of the full ADAGIO cohort and 72% of ADAGIO completers). At baseline, mean time from diagnosis was 46.9 months and UPDRS total score was 25.6 units. There were no significant differences in UPDRS total or subscale scores or time to any milestone between patients who were in the original ADAGIO early-start group versus those in the delayed-start group. At study end, patients (total cohort) had worsened by a mean ± standard deviation of 6.0 ± 11.6 UPDRS total units, 3.3 ± 8.6 UPDRS motor units and 2.0 ± 4.0 UPDRS activities of daily living (ADL) units. Overall, 43.6% of patients had onset of unsteady gait/balance impairment, 35.7% had fallen, 26.2% had freezing of gait, and 33.1% had cognitive decline.

CONCLUSIONS

The ADAGIO Follow-Up study failed to demonstrate long-term benefits of early-start rasagiline treatment in the prior ADAGIO study. Clinically important milestones occurred in a substantial proportion of patients. © 2016 International Parkinson and Movement Disorder Society.

Longer Duration of MAO-B Inhibitor Exposure is Associated with Less Clinical Decline in Parkinson's Disease: An Analysis of NET-PD LS1

BACKGROUND

Monoamine oxidase type B (MAO-B) inhibitors exhibit neuroprotective effects in preclinical models of PD but clinical trials have failed to convincingly demonstrate disease modifying benefits in PD patients.

OBJECTIVE

To perform a secondary analysis of NET-PD LS1 to determine if longer duration of MAO-B inhibitor exposure was associated with less clinical decline.

METHODS

The primary outcome measure was the Global Outcome (GO), comprised of 5 measures: change from baseline in the Schwab and England (ADL) scale, the 39-item Parkinson's Disease Questionnaire (PDQ-39), the UPDRS Ambulatory Capacity Scale, the Symbol Digit Modalities Test, and the most recent Modified Rankin Scale. A linear mixed model was used to explore the association between the cumulative duration of MAO-B inhibitor exposure and the GO, adjusting for necessary factors and confounders. Associations between MAO-B inhibitor exposure and each of the five GO components were then studied individually.

RESULTS

1616 participants comprised the analytic sample. Mean observation was 4.1 (SD = 1.4) years, and 784 (48.5%) participants received an MAO-B inhibitor. The regression coefficient of cumulative duration of MAO-B inhibitor exposure (in years) on the GO was - 0.0064 (SE = 0.002, p = 0.001). Significant associations between duration of MAO-B inhibitor exposure and less progression were observed for ADL (p < 0.001), Ambulatory Capacity (p < 0.001), and the Rankin (p = 0.002).

CONCLUSIONS

Our analysis identified a significant association between longer duration of MAO-B inhibitor exposure and less clinical decline. These findings support the possibility that MAO-B inhibitors slow clinical disease progression and suggest that a definitive prospective trial should be considered.

Use, maintenance and dose effects of cognitive speed of processing training in Parkinson's disease

INTRODUCTION

Recent research indicated that cognitive speed of processing training (SPT) improved Useful Field of View (UFOV) among individuals with Parkinson's disease (PD). The effects of SPT in PD have not been further examined. The objectives of the current study were to investigate use, maintenance and dose effects of SPT among individuals with PD.

METHODS

Participants who were randomized to SPT or a delayed control group completed the UFOV at a six-month follow-up visit. Use of SPT was monitored across the six-month study period. Regression explored factors affecting SPT use. Mixed effect models were conducted to examine the durability of training gains among those randomized to SPT (n = 44), and training dose effects among the entire sample (n = 87).

RESULTS

The majority of participants chose to continue to use SPT (52%). Those randomized to SPT maintained improvements in UFOV performance. A significant dose effect of SPT was evident such that more hours of training were associated with greater UFOV performance improvements. The cognitive benefits derived from SPT in PD may be maintained for up to three months.

CONCLUSION

Future research should determine how long gains endure and explore if such training gains transfer.

ADS-5102 (Amantadine) Extended-Release Capsules for Levodopa-Induced Dyskinesia in Parkinson Disease (EASE LID Study): A Randomized Clinical Trial

Importance

Medical treatment of levodopa-induced dyskinesia (LID) in Parkinson disease (PD) is an unmet need.

Objective

To evaluate the efficacy and safety of ADS-5102 (amantadine) extended-release 274-mg capsules for treatment of LID in patients with PD.

Design, Setting, and Participants

A randomized, double-blind, placebo-controlled clinical trial was conducted between May 7, 2014, and July 22, 2015, at 44 North American sites among patients with PD treated with levodopa who experienced at least 1 hour of troublesome dyskinesia per day with at least mild functional impact.

Interventions

Patients were randomized to receive placebo or 274 mg of ADS-5102 administered orally at bedtime for up to 25 weeks.

Main Outcomes and Measures

The primary efficacy analysis was the change from baseline to week 12 in the Unified Dyskinesia Rating Scale total score for ADS-5102 vs placebo in the modified intent-to-treat population. OFF time (amount of time the PD medication is not controlling motor symptoms) was a key secondary end point. Safety analyses included all patients who received the study drug (ADS-5102 or placebo).

Results

A total of 189 patients were screened, and 126 were randomized; the modified intent-to-treat population included 121 patients (51 women and 70 men; mean [SD] age, 64.7 [9.1] years). At week 12, the least-squares mean (SE) change in the Unified Dyskinesia Rating Scale score was -15.9 (1.6) for ADS-5102 (n = 63) and -8.0 (1.6) for placebo (n = 58) (treatment difference, -7.9; 95% CI, -12.5 to -3.3; P < .001). OFF time decreased by a mean (SE) of 0.6 (0.3) hours for ADS-5102 and increased by 0.3 (0.3) hours for placebo (treatment difference, -0.9 hours; 95% CI, -1.6 to -0.2; P = .02). Common adverse events for ADS-5102 vs placebo included visual hallucinations (15 [23.8%] vs 1 [1.7%]), peripheral edema (15 [23.8%] vs 0), and dizziness (14 [22.2%] vs 0). Adverse events led to treatment discontinuation for 13 patients receiving ADS-5102 (20.6%) vs 4 patients receiving placebo (6.9%).

Conclusions and Relevance

ADS-5102, 274 mg at bedtime, may be an effective treatment for LID. An additional benefit is reduced OFF time. To our knowledge, this is the first demonstration of an oral treatment reducing both LID and OFF time in patients with PD with dyskinesia.

Trial Registration

clinicaltrials.gov Identifier: NCT02136914.

Randomized, placebo-controlled trial of ADS-5102 (amantadine) extended-release capsules for levodopa-induced dyskinesia in Parkinson's disease (EASE LID 3)

BACKGROUND

The treatment of levodopa-induced dyskinesia in Parkinson's disease (PD) is an unmet need with no approved drug therapy.

OBJECTIVE

The purpose of this study was to investigate the efficacy and safety of 274 mg ADS-5102 (amantadine) extended-release capsules (equivalent to 340-mg amantadine HCl) for levodopa-induced dyskinesia in a randomized controlled trial.

METHODS

PD patients with ≥1 hour of troublesome dyskinesia and at least mild functional impact were randomized to placebo or ADS-5102 once daily at bedtime for 13 weeks. The primary efficacy analysis was based on change from baseline to week 12 on the Unified Dyskinesia Rating Scale total score in the modified intent-to-treat population. OFF time was a key secondary measure.

RESULTS

At week 12, least-squares mean change in the Unified Dyskinesia Rating Scale was -20.7 (standard error 2.2) for ADS-5102 (n = 37) and -6.3 (standard error 2.1) for placebo (n = 38; treatment difference -14.4, 95% confidence interval -20.4 to -8.3, P < .0001), indicating improvement in levodopa-induced dyskinesia. OFF time decreased 0.5 hours (standard error 0.3) for ADS-5102 from a baseline mean of 2.6 hours and increased 0.6 hours (standard error 0.3) for placebo from a baseline mean of 2.0 hours (treatment difference -1.1 hours, 95% confidence interval -2.0 to -0.2, P = .0199). The most common adverse events (ADS-5102 versus placebo) included dry mouth (13.5% versus 2.6%), nausea (13.5% versus 2.6%), decreased appetite (10.8% versus 0%), insomnia (10.8% versus 0%), orthostatic hypotension (10.8% versus 0%), constipation (8.1% versus 0%), falls (8.1% versus 5.3%), and visual hallucinations (8.1% versus 5.3%). Adverse events led to treatment discontinuation in 19% versus 8%, respectively.

CONCLUSION

ADS-5102 274 mg is an oral pharmacotherapy demonstrating a significant decrease in levodopa-induced dyskinesia and improving OFF time. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Valbenazine for the treatment of tardive dyskinesia

INTRODUCTION

Tardive dyskinesia (TD) is a hyperkinetic movement disorder that may result from treatment with antipsychotics or other dopamine receptor blocking agents. Underlying pathophysiology is incompletely understood but since the 1970s dopamine depleting agents have been used to reduce involuntary movements. The search for safe, effective treatments for TD is ongoing. Valbenazine, a novel VMAT2 inhibitor, has recently been FDA approved for treatment of TD. Areas covered: An overview of TD, unmet medical needs and current treatment guidelines are presented. The background, chemistry and clinical development of valbenazine to treat TD is detailed. A competitive market is developing as the treatment gap is identified and potential therapies are discussed in context of a broader market overview. Expert opinion: Antipsychotic use is growing among adults and children in the U.S. Consequently, prevalence of TD is expected to rise. Cessation of antipsychotics is often not possible as the psychiatric condition may deteriorate. Increasing doses of an antipsychotic to suppress involuntary movements is not sustainable long term as underlying TD worsens and movements typically recur. There were no FDA approved treatments for TD. The approval of valbenazine to treat TD is a critical step in addressing this gap in neurologic care.

Deutetrabenazine for treatment of involuntary movements in patients with tardive dyskinesia (AIM-TD): a double-blind, randomised, placebo-controlled, phase 3 trial

BACKGROUND

Tardive dyskinesia results from exposure to dopamine receptor antagonists, such as typical and atypical antipsychotics. If clinically appropriate, clinicians often manage this disorder by lowering the dose of, or discontinuing, the causative drug. There is a significant unmet need for a treatment option that does not disrupt treatment regimens for underlying psychiatric illnesses. We aimed to assess the efficacy, safety, and tolerability of fixed doses of deutetrabenazine-a novel vesicular monoamine transporter-2 inhibitor-in patients with tardive dyskinesia.

METHODS

We did this double-blind, randomised, placebo-controlled, phase 3 trial at 75 centres in the USA and Europe. Patients aged 18-80 years with tardive dyskinesia (≥3 months before screening) were randomly assigned centrally (1:1:1:1), via interactive response technology, to receive one of three fixed doses of deutetrabenazine (12 mg/day, 24 mg/day, or 36 mg/day) or matching placebo. Randomisation was stratified by baseline use of dopamine receptor antagonists. Patients were started on oral deutetrabenazine 12 mg/day, and this dose was increased through week 4 until the randomised dose was achieved, then maintained over 8 weeks. During the treatment period, patients, investigators, their site personnel, and sponsor were masked to group assignment. The primary efficacy endpoint was change in Abnormal Involuntary Movement Scale (AIMS) score from baseline to week 12 in patients with at least one post-baseline rating. The primary efficacy analysis was done in the modified intention-to-treat population (baseline AIMS score ≥6 and at least one post-baseline rating). The safety analysis was done in patients who received any study drug. This trial is registered with ClinicalTrials.gov, number NCT02291861.

FINDINGS

Between Oct 29, 2014, and Aug 19, 2016, we randomly assigned 298 patients to receive at least one dose of placebo (n=74), deutetrabenazine 12 mg/day (n=75), 24 mg/day (n=74), or 36 mg/day (n=75); 222 patients comprised the modified intention-to-treat population and 293 patients comprised the safety population. From baseline to week 12, the least-squares mean AIMS score improved by -3·3 points (SE 0·42) in the deutetrabenazine 36 mg/day group, -3·2 points (0·45) in the 24 mg/day group, and -2·1 points (0·42) in the 12 mg/day group, with a treatment difference of -1·9 points (SE 0·58, 95% CI -3·09 to -0·79; p=0·001), -1·8 points (0·60, -3·00 to -0·63; p=0·003), and -0·7 points (0·57, -1·84 to 0·42; p=0·217), respectively, versus -1·4 points (0·41) in the placebo group. The rate of adverse events was similar between patients in the deutetrabenazine 36 mg/day group (n=38/74 [51%]), 24 mg/day group (n=32/73 [44%]), and 12 mg/day group (n=36/74 [49%]), and those in the placebo group (n=34/72 [47%]). Serious adverse events were reported in four (5%) patients given deutetrabenazine 36 mg/day, six (8%) patients given 24 mg/day, and two (3%) patients given 12 mg/day, compared with four (6%) patients given placebo. Two (1%) patients in the safety population died, one each in the deutetrabenazine 24 mg/day and 36 mg/day groups; neither death was deemed related to study drug by the investigator or sponsor.

INTERPRETATION

Deutetrabenazine 24 mg/day and 36 mg/day provided a significant reduction in tardive dyskinesia, with favourable safety and tolerability. These findings suggest that dosing regimens could be individualised and tailored for patients on the basis of dyskinesia control and tolerability.

FUNDING

Teva Pharmaceutical Industries.