Safety and efficacy of continuous subcutaneous levodopa-carbidopa infusion (ND0612) for Parkinson's disease with motor fluctuations (BouNDless): a phase 3, randomised, double-blind, double-dummy, multicentre trial.

BACKGROUND: Conventional oral levodopa therapy for the treatment of Parkinson's disease can be associated with variations in plasma concentrations. Levodopa infusion strategies might provide more consistent drug delivery and fewer motor fluctuations. We aimed to assess the safety and efficacy of a continuous 24 h/day subcutaneous infusion of ND0612 (a levodopa-carbidopa solution) compared with oral immediate-release levodopa-carbidopa for the treatment of motor fluctuations in people with Parkinson's disease. METHODS: We conducted a phase 3, randomised, double-blind, double-dummy, active-controlled, multicentre trial at 117 academic and community neurology sites in 16 countries, including in Europe, Israel, and the USA. Eligible participants were men and women aged 30 years or older with a diagnosis of Parkinson's disease (Hoehn and Yahr stage ≤3 in the on state) who experienced at least 2·5 h/day of off time. Participants underwent an open-label run-in phase (<12 weeks), during which time optimal regimens were established for both oral immediate-release levodopa-carbidopa and for 24 h/day subcutaneous ND0612 infusion (levodopa-carbidopa 60·0/7·5 mg/mL), with supplemental oral levodopa-carbidopa if needed. Participants were then randomly assigned (1:1) to 12 weeks of double-blind treatment with their optimised regimen of either subcutaneous ND0612 or oral levodopa-carbidopa, with matching oral or subcutaneous placebo given as required to maintain blinding. Randomisation was done via an interactive web response system, stratified by region, using a permuted block schedule. Participants, study partners, treating investigators, study site personnel, and the sponsor were masked to treatment group allocation. The primary efficacy endpoint was the change from baseline (ie, time of randomisation, when all patients were receiving an optimised open-label ND0612 regimen) to end of the double-blind phase in total daily on time without troublesome dyskinesia, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, NCT04006210, and is complete. FINDINGS: Between Sept 30, 2019, and April 8, 2022, 381 participants were enrolled, of whom 259 (68%) were randomly assigned, 128 (49%) to subcutaneous ND0612 and 131 (51%) to oral levodopa-carbidopa. 243 (94%) participants completed the study. Treatment with subcutaneous ND0612 provided an additional 1·72 h (95% CI 1·08 to 2·36) of on time without troublesome dyskinesia compared with oral levodopa-carbidopa (change from baseline of -0·48 h [-0·94 to -0·02] with subcutaneous ND0612 vs -2·20 h [-2·65 to -1·74] with oral levodopa-carbidopa; p<0·0001). Significant treatment differences favouring subcutaneous ND0612 were also found in the first four of nine prespecified hierarchical outcomes of daily off time (-1·40 h [95% CI -1·99 to -0·80]), Movement Disorders Society-Unified Parkinson's Disease Rating Scale part II scores (-3·05 [-4·28 to -1·81]), Patients Global Impression of Change (odds ratio [OR] 5·31 [2·67 to 10·58]), and Clinical Global Impression of Improvement (OR 7·23 [3·57 to 14·64]). Hierarchical testing ended after the fourth secondary endpoint. Adverse events were reported by 287 (89%) of 322 participants during open-label ND0612 optimisation, and by 103 (80%) of 128 in the ND0612 group and 97 (74%) of 131 in the oral levodopa-carbidopa group during the double-blind phase. The most common adverse events were infusion-site reactions (266 [83%] participants during open-label ND0612, and 73 [57%] in the ND0612 group vs 56 [43%] in the oral levodopa-carbidopa group during the double-blind phase), most of which were mild. Serious adverse events in four participants in the ND0612 group were related to study treatment (infusion-site cellulitis [n=2], infusion-site abscess and infusion-site ulcer [n=1]; and paraesthesia and peripheral sensorimotor neuropathy [n=1]). One participant in the ND0612 group died during the double-blind phase, but the death was not related to study treatment (fall leading to traumatic brain injury). INTERPRETATION: Results of this phase 3 study showed that subcutaneous ND0612 used in combination with oral immediate-release levodopa-carbidopa increased on time without troublesome dyskinesia and reduced off time, with a favourable benefit-risk profile. ND0612 might offer a safe and efficacious subcutaneous levodopa infusion approach to managing motor fluctuations in people with Parkinson's disease. The ongoing open-label extension phase will provide further information on the long-term efficacy and safety of treatment. FUNDING: NeuroDerm.

A Phase I, Randomized, SAD, MAD, and PK Study of Risvodetinib in Older Adults and Parkinson's Disease.

Background: Pre-clinical studies suggest that c-Abl activation may play an important role in the etiology of Parkinson's disease, making c-Abl an important target to evaluate for potential disease-modification. Objective: To assess safety, tolerability, and pharmacokinetics of the c-Abl inhibitor risvodetinib (IkT-148009) in healthy subjects and participants with Parkinson's disease. Methods: Part 1 (single ascending dose (SAD)) and Part 2 (7-day multiple ascending dose (MAD)) studies were in healthy volunteers. Participants were randomized 3 : 1 across 9 SAD doses and 3 MAD doses of risvodetinib (IkT-148009) or placebo. Part 3 was a MAD study conducted at two doses in 14 participants with mild-to-moderate PD (MAD-PD). Primary outcome measures were safety, tolerability and pharmacokinetics. Exploratory outcomes in PD participants included clinical measures of PD state, GI function, and cerebrospinal fluid (CSF) concentration. Results: 108 patients were treated with no dropouts. The SAD tested doses ranging from 12.5 to 325 mg, while the MAD tested 25 to 200 mg and MAD-PD tested 50 to 100 mg in Parkinson's participants. All active doses had a favorable safety profile with no clinically meaningful adverse events. Single dose pharmacokinetics were approximately linear between 12.5 mg and 200 mg for both Cmax and AUC0 - inf without distinction between healthy volunteers and participants with PD. Exposures at each dose were high relative to other drugs in the same kinase inhibitor class. Conclusions: Risvodetinib (IkT-148009) was well tolerated, had a favorable safety and pharmacology profile over 7-day dosing, did not induce serious adverse events and did not appear to induce deleterious side-effects in participants administered anti-PD medications.

IPX203 vs Immediate-Release Carbidopa-Levodopa for the Treatment of Motor Fluctuations in Parkinson Disease: The RISE-PD Randomized Clinical Trial.

Importance: Levodopa has a short half-life and a limited window of opportunity for absorption in the proximal small intestine. IPX203 is an oral, extended-release formulation of carbidopa-levodopa developed to address these limitations. Objective: To assess the efficacy and safety of IPX203 vs immediate-release carbidopa-levodopa in patients with Parkinson disease who are experiencing motor fluctuations. Design, Setting, and Participants: RISE-PD was a 20-week, randomized, double-blind, double-dummy, active-controlled, phase 3 clinical trial. The study was conducted between November 6, 2018, and June 15, 2021, at 105 academic and clinical centers in the US and Europe. Patients with Parkinson disease taking a total daily dose of 400 mg or more of levodopa and experiencing an average of 2.5 hours or more daily off-time were included in the study. A total of 770 patients were screened, 140 were excluded (those taking controlled-release carbidopa-levodopa apart from a single daily bedtime dose, Rytary (Amneal Pharmaceuticals), additional carbidopa or benserazide, or catechol O-methyl transferase inhibitors or who had a history of psychosis within the past 10 years), and 630 were enrolled in the trial. Interventions: Following open-label immediate-release carbidopa-levodopa dose adjustment (3 weeks) and conversion to IPX203 (4 weeks), patients were randomized in a 1:1 ratio to double-blind, double-dummy treatment with immediate-release carbidopa-levodopa or IPX203 for 13 weeks. Main Outcome and Measures: The primary end point was mean change in daily good on-time (ie, on-time without troublesome dyskinesia) from baseline to the end of the double-blind treatment period. Results: A total of 630 patients (mean [SD] age, 66.5 [8.95] years; 396 [62.9%] men) were enrolled, and 506 patients were randomly assigned to receive IPX203 (n = 256) or immediate-release carbidopa-levodopa (n = 250). The study met its primary end point, demonstrating statistically significant improvement in daily good on-time for IPX203 compared to immediate-release carbidopa-levodopa (least squares mean, 0.53 hours; 95% CI, 0.09-0.97; P = .02), with IPX203 dosed a mean 3 times per day vs 5 times per day for immediate-release carbidopa-levodopa. Good on-time per dose increased by 1.55 hours with IPX203 compared to immediate-release carbidopa-levodopa (95% CI, 1.37-1.73; P < .001). IPX203 was well tolerated. The most common adverse events in the double-blind phase (IPX203 vs immediate-release carbidopa-levodopa) were nausea (4.3% vs 0.8%) and anxiety (2.7% vs 0.0%). Conclusions and Relevance: In this study, IPX203 provided more hours of good on-time per day than immediate-release carbidopa-levodopa, even as IPX203 was dosed less frequently. Trial Registration: ClinicalTrials.gov Identifier: NCT03670953.

Improving levodopa delivery: IPX203, a novel extended-release carbidopa-levodopa formulation.

Introduction: IPX203 is a novel oral extended-release (ER) formulation of carbidopa (CD) and levodopa (LD) developed to address the short half-life and limited area for absorption of LD in the gastrointestinal tract. This paper presents the formulation strategy of IPX203 and its relationship to the pharmacokinetics (PK) and pharmacodynamic profile of IPX203 in Parkinson's disease (PD) patients. Methods: IPX203 was developed with an innovative technology containing immediate-release (IR) granules and ER beads that provides rapid LD absorption to achieve desired plasma concentration and maintaining it within the therapeutic range for longer than can be achieved with current oral LD formulations. The PK and pharmacodynamics of IPX203 were compared with IR CD-LD in a Phase 2, open-label, rater-blinded, multicenter, crossover study in patients with advanced PD. Results: Pharmacokinetic data showed that on Day 15, LD concentrations were sustained above 50% of peak for 6.2 h with IPX203 vs. 3.9 h with IR CD-LD (P = 0.0002). Pharmacodynamic analysis demonstrated that mean MDS-UPDRS Part III scores prior to administration of the first daily dose were significantly lower among patients receiving IPX203 than IR CD-LD (LS mean difference -8.1 [25.0], P = 0.0255). In a study conducted in healthy volunteers, a high-fat, high-calorie meal delayed plasma LD Tmax by 2 h, and increased Cmax and AUCtau by approximately 20% compared with a fasted state. Sprinkling capsule contents on applesauce did not affect PK parameters. Conclusion: These data confirm that the unique design of IPX203 addresses some of the limitations of oral LD delivery.

Preclinical and clinical evaluation of the LRRK2 inhibitor DNL201 for Parkinson's disease.

Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common genetic risk factors for Parkinson's disease (PD). Increased LRRK2 kinase activity is thought to impair lysosomal function and may contribute to the pathogenesis of PD. Thus, inhibition of LRRK2 is a potential disease-modifying therapeutic strategy for PD. DNL201 is an investigational, first-in-class, CNS-penetrant, selective, ATP-competitive, small-molecule LRRK2 kinase inhibitor. In preclinical models, DNL201 inhibited LRRK2 kinase activity as evidenced by reduced phosphorylation of both LRRK2 at serine-935 (pS935) and Rab10 at threonine-73 (pT73), a direct substrate of LRRK2. Inhibition of LRRK2 by DNL201 demonstrated improved lysosomal function in cellular models of disease, including primary mouse astrocytes and fibroblasts from patients with Gaucher disease. Chronic administration of DNL201 to cynomolgus macaques at pharmacologically relevant doses was not associated with adverse findings. In phase 1 and phase 1b clinical trials in 122 healthy volunteers and in 28 patients with PD, respectively, DNL201 at single and multiple doses inhibited LRRK2 and was well tolerated at doses demonstrating LRRK2 pathway engagement and alteration of downstream lysosomal biomarkers. Robust cerebrospinal fluid penetration of DNL201 was observed in both healthy volunteers and patients with PD. These data support the hypothesis that LRRK2 inhibition has the potential to correct lysosomal dysfunction in patients with PD at doses that are generally safe and well tolerated, warranting further clinical development of LRRK2 inhibitors as a therapeutic modality for PD.

Interindividual Variability in the Bioavailability of Gabapentin Enacarbil Extended Release in Healthy Adults: An Analysis of Data From 6 Phase I Studies.

BACKGROUND: The absorption and bioavailability of oral gabapentin are associated with a high degree of interindividual variability. Gabapentin enacarbil, a prodrug of gabapentin, is well absorbed and provides sustained, dose-proportional exposure to gabapentin. The aim of this analysis was to describe the interindividual variability in the bioavailability of gabapentin after gabapentin enacarbil administration in healthy subjects. METHODS: Gabapentin pharmacokinetic (PK) parameters after an oral dose of gabapentin enacarbil 1200 mg (2 600-mg tablets) were compared across 6 phase I studies in healthy adults (n = 12 per study). The distribution of bioavailability values was assessed in all studies. RESULTS: The mean PK parameters of gabapentin were consistent across the trials: maximum concentration range: 6.4-7.9 µg/mL, time to maximum concentration range: 5.2-8.2 hours, area under the plasma-concentration curve extrapolated from time 0 to infinity or at steady state range: 70.8-109.4 µg·h/mL, and bioavailability range: 64.8%-82.9%. Overall, the mean bioavailability was 74.1% (SD, 14.1; coefficient of variation, 19.1%). Individual bioavailability across all studies ranged from 42% to 100%. CONCLUSIONS: Gabapentin PK after gabapentin enacarbil administration was consistent across studies, with low interindividual variability in bioavailability. Gabapentin enacarbil may provide more consistent and predictable exposure to gabapentin than oral gabapentin formulations.

Subcutaneous Levodopa Infusion for Parkinson's Disease: 1-Year Data from the Open-Label BeyoND Study.

BACKGROUND: Continuous, subcutaneous (SC) levodopa/carbidopa infusion with ND0612 is under development as a treatment for patients with Parkinson's disease (PD) and motor fluctuations. OBJECTIVE: Evaluate 1-year safety data. METHODS: BeyoND is an open-label study evaluating the long-term safety of two ND0612 dosing regimens. RESULTS: Of the 214 enrolled patients (24-hour SC infusion: n = 90; 16-hour SC infusion: n = 124), 120 (56%) completed 12 months of treatment. Leading causes for study discontinuation were consent withdrawal (19.6%) and adverse events (17.3%). Rates of discontinuation were reduced from 49% to 29% after a protocol revision and retraining. Systemic safety was typical for PD patients treated with levodopa/carbidopa. Most patients experienced infusion site reactions, particularly nodules (30.8%) and hematoma (25.2%), which were judged mostly mild to moderate and led to discontinuation in only 10.3% of the participants. CONCLUSIONS: Subcutaneous levodopa/carbidopa continuous infusion with ND0612 is generally safe, with typical infusion site reactions for SC delivery as the main adverse event. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Continuous Subcutaneous Levodopa Delivery for Parkinson's Disease: A Randomized Study.

BACKGROUND: ND0612 is a continuous, subcutaneous levodopa/carbidopa delivery system in development for patients with Parkinson's disease (PD) experiencing motor fluctuationsObjective:Evaluate the efficacy and safety of two ND0612 dosing regimens in patients with PD. METHODS: This was a 28-day open-label study (NCT02577523) in PD patients with ≥2.5 hours/day of OFF time despite optimized treatment. Patients were randomized to treatment with either a 24-hour infusion (levodopa/carbidopa dose of 720/90 mg) or a 14-hour 'waking-day' infusion (levodopa/carbidopa dose of 538/68 mg plus a morning oral dose of 150/15 mg). Supplemental oral doses of levodopa were permitted for patients in both groups if required. In-clinic assessments of OFF time (primary endpoint) and ON time with or without dyskinesia were determined by a blinded rater over 8 hours (normalized to 16 hours). RESULTS: A total of 38 patients were randomized and 33 (87%) completed the study. Compared to baseline, OFF time for the overall population was reduced by a least squares (LS) mean[95% CI] of 2.0[- 3.3, - 0.7] hours (p = 0.003). ON time with no/mild dyskinesia (no troublesome dyskinesia) was increased from baseline by a LS mean of 3.3[2.0, 4.6] hours (p < 0.0001), and ON time with moderate/severe dyskinesia was reduced by a LS mean of 1.2[- 1.8, - 0.5] hours (p≤0.001). Reduction in OFF time was larger in the 24-hour group (- 2.8[- 4.6, - 0.9] hours; p = 0.004) than in the 14-hour group (- 1.3[- 3.1, 0.5] hours; p = 0.16). Complete resolution of OFF time was observed in 42% (n = 8) of patients in the 24-hour group. Infusion site reactions were the most common adverse event. CONCLUSION: This study demonstrates the feasibility and safety of continuous subcutaneous delivery of levodopa as a treatment for PD and provides preliminary evidence of efficacy.

Pharmacokinetics of Inhaled Levodopa Administered With Oral Carbidopa in the Fed State in Patients With Parkinson's Disease.

PURPOSE: Levodopa (LD) is the most effective oral pharmacotherapy for the management of motor symptoms in Parkinson's disease. However, LD use is complicated by a progressive shortening of the duration of efficacy of a dose, resulting in episodes of inadequate responsiveness, or OFF periods. OFF periods may also occur unpredictably, partly due to the pharmacokinetic (PK) variability of oral LD, resulting from gastrointestinal dysfunction and from the effects of food on absorption. CVT-301 is a levodopa inhalation powder for the treatment of OFF period symptoms in patients on oral dopa-decarboxylase inhibitor/LD. PK and safety profiles of single dose CVT-301, administered with oral carbidopa (CD) and oral CD/LD, were examined in patients with Parkinson's disease in the fed state. METHODS: Eligible patients were aged 30-85 years, with a clinical diagnosis of Parkinson's disease and a body mass index of 18-32 kg/m2, and were receiving treatment with a stable regimen that included oral CD/LD (25/100 mg) (total LD, ≤800 mg/d). A high-fat/protein meal was eaten 4-5 h after the administration of the morning oral CD/LD dose. Blood samples for predose PK analysis were obtained after the meal, followed by a single inhaled dose of CVT-301 84 mg (+25 mg of oral CD) or oral CD/LD (25/100 mg) or vice versa in 2 dosing periods in a crossover design. Blood was sampled at 0, 5, 10, 15, 30, and 45 min and at 1, 1.5, 2, 3, and 4 h postdose. Tolerability assessments included treatment-emergent adverse events. FINDINGS: Twenty-three patients were enrolled (65.2% male; 87.0% white; mean age, 69.3 years; mean body mass index, 26.9 kg/m2; mean Parkinson's disease duration, 8.2 years; mean baseline LD dosage, 460.9 mg/d; 73.9% at Hoehn and Yahr stage <2.5). PK analyses were based on LD concentrations without baseline adjustment. Median Tmax values with CVT-301 and oral CD/LD were 15 and 120 min (P < 0.001). Cmax with CVT-301 was lower than with oral CD/LD (590.3 vs 844.3 ng/mL). C10min and C30min values with CVT-301 were approximately twice those with CD/LD (522.9 and 531.5 ng/mL vs 247.3 and 300.9 ng/mL, respectively). %CV for C5min to Cmax with CVT-301 was lower than that with oral CD/LD. The most common treatment-emergent adverse event was cough (CVT-301, 7 patients [30.4%]; oral CD/LD, 1 patient [4.5%]). IMPLICATIONS: PK properties showed that CVT-301 was more rapidly absorbed, with higher plasma LD concentrations in the first 45 min, and demonstrated lower interpatient variability, than was oral CD/LD in the fed condition. The study findings suggest that CVT-301 can be used without regard to food intake. ClinicalTrials.gov identifier: NCT03887884.

Randomized phase I clinical trial of anti-α-synuclein antibody BIIB054.

BACKGROUND: Pathological and genetic evidence implicates toxic effects of aggregated α-synuclein in the pathophysiology of neuronal dysfunction and degeneration in Parkinson's disease. Immunotherapy targeting aggregated α-synuclein is a promising strategy for delaying disease progression. OBJECTIVE: This study (NCT02459886) evaluated the safety, tolerability, and pharmacokinetics of BIIB054, a human-derived monoclonal antibody that preferentially binds to aggregated α-synuclein, in healthy volunteers and participants with Parkinson's disease. METHODS: A total of 48 healthy volunteers (age 40-65, 19 women) and 18 Parkinson's disease participants (age 47-75, 5 women, Hoehn and Yahr stage ≤2.5) were in the study. Volunteers were enrolled into 6 single-dose cohorts of BIIB054 (range 1-135 mg/kg) or placebo, administered intravenously; Parkinson's disease participants received a single dose of BIIB054 (15 or 45 mg/kg) or placebo. All participants were evaluated for 16 weeks with clinical, neuroimaging, electrocardiogram, and laboratory assessments. Serum and cerebrospinal fluid BIIB054 concentrations were measured. BIIB054/α-synuclein complexes were measured in plasma. RESULTS: Most adverse events were mild and assessed by investigators as unrelated to the study drug. Pharmacokinetic parameters for volunteers and the Parkinson's disease participants were similar. BIIB054 serum exposure and maximum concentrations were dose proportional during the dose range studied. In volunteers and the Parkinson's disease participants, the serum half-life of BIIB054 was 28 to 35 days; the cerebrospinal fluid-to-serum ratio ranged from 0.13% to 0.56%. The presence of BIIB054/α-synuclein complexes in plasma was confirmed; all Parkinson's disease participants showed almost complete saturation of the BIIB054/α-synuclein complex formation. CONCLUSIONS: BIIB054 has favorable safety, tolerability, and pharmacokinetic profiles in volunteers and Parkinson's disease participants, supporting further clinical development. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Orally inhaled levodopa (CVT-301) for early morning OFF periods in Parkinson's disease.

BACKGROUND: CVT-301 (Inbrija) is a self-administered orally inhaled levodopa approved for the intermittent treatment of OFF episodes in patients with Parkinson's disease (PD) treated with carbidopa/levodopa. Prior studies only evaluated CVT-301 after the first ON of the day. OBJECTIVE AND METHODS: The objective of this study was to evaluate the safety and tolerability of CVT-301 for early morning OFF. Using a randomized, double-blind, 2-way crossover design, eligible patients in the morning OFF state (having not received PD medication overnight) received a single dose of CVT-301 84 mg or placebo on 2 dosing days, immediately after their first morning oral carbidopa/levodopa dose. Safety assessments included treatment-emergent adverse events, vital signs, and patient- and examiner-reported dyskinesia. An exploratory efficacy assessment was examiner-rated time-to-ON with carbidopa/levodopa + CVT-301 vs carbidopa/levodopa + placebo. RESULTS: Of the 36 patients (mean age 62.9 years) who enrolled and completed the study, 9 (25.0%) reported treatment-emergent adverse events following CVT-301 administration; 4 (11.1%) reported treatment-emergent adverse events following placebo. The most common adverse event was cough (4 [11.1%] for CVT-301 vs 1 [2.8%] for placebo), which was typically mild and transient. Incidence of asymptomatic orthostatic hypotension (CVT-301, 6; placebo, 7) and examiner-rated dyskinesia were similar for both (36-39% mild, 3-6% moderate, and 0% severe). Median time-to-ON was 25.0 min following carbidopa/levodopa + CVT-301 and 35.5 min following carbidopa/levodopa + placebo (P = 0.26). At 30 min, more patients had turned ON following carbidopa/levodopa + CVT-301 administration (66.7%), compared with carbidopa/levodopa + placebo (44.5%) (P = 0.040). CONCLUSION: Single doses of CVT-301 84 mg administered with oral carbidopa/levodopa for early morning OFF symptoms were well-tolerated, with no notable safety concerns.

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.

Safety and Tolerability of Multiple Ascending Doses of PRX002/RG7935, an Anti-α-Synuclein Monoclonal Antibody, in Patients With Parkinson Disease: A Randomized Clinical Trial.

Importance: Aggregated α-synuclein is believed to be central to the pathogenesis of Parkinson disease (PD). PRX002/RG7935 (PRX002) is a humanized monoclonal antibody designed to target aggregated forms of α-synuclein, thereby inhibiting neuron-to-neuron transfer of presumed pathogenic forms of α-synuclein, potentially resulting in neuronal protection and slowing disease progression. Objective: To evaluate the safety and tolerability of multiple intravenous infusions of PRX002 in patients with idiopathic PD. Design, Setting, and Participants: Multicenter, randomized, double-blind, placebo-controlled, multiple ascending-dose trial at 8 US study centers from July 2014 to September 2016. Eligible participants were aged 40 to 80 years with mild to moderate idiopathic PD (Hoehn and Yahr stages 1-3). Interventions: Participants were enrolled into 6 ascending-dose cohorts and randomly assigned to receive PRX002 (0.3 mg/kg, 1.0 mg/kg, 3.0 mg/kg, 10 mg/kg, 30 mg/kg, or 60 mg/kg) or placebo. Participants received 3 intravenous infusions every 4 weeks of PRX002 or placebo and were monitored during a 24-week observational period. Main Outcomes and Measures: Safety and tolerability assessments included physical and neurological examinations, laboratory tests, vital signs, and adverse events. Pharmacokinetic parameters included maximum PRX002 concentration, area under the curve, and half-life. Results: Of the 80 participants, most were white (97.5%; n = 78) and male (80%; n = 64); median (SD) age was 58 (8.4) years. PRX002 was generally safe and well tolerated; no serious or severe PRX002-related treatment-emergent adverse events (TEAEs) were reported. The TEAEs experienced by at least 5% of patients receiving PRX002, irrespective of relatedness to study drug, were constipation (9.1%; n = 5), infusion reaction (7.3%; n = 4), diarrhea (5.5%; n = 3), headache (5.5%; n = 3), peripheral edema (5.5%; n = 3), post-lumbar puncture syndrome (5.5%; n = 3), and upper respiratory tract infection (5.5%; n = 3). No antidrug antibodies were detected. Serum PRX002 levels increased in an approximately dose-proportional manner; mean terminal elimination half-life was similar across all doses (10.2 days). Rapid dose- and time-dependent mean reductions from baseline vs placebo in free serum α-synuclein levels of up to 97% were seen after a single infusion at the highest dose (F78,284 = 1.66; P = .002), with similar reductions after 2 additional infusions. Mean cerebrospinal fluid PRX002 concentration increased with PRX002 dose and was approximately 0.3% relative to serum across all dose cohorts. Conclusions and Relevance: Single and multiple doses of PRX002 were generally safe and well tolerated and resulted in robust binding of peripheral α-synuclein and dose-dependent increases of PRX002 in cerebrospinal fluid, reaching cerebrospinal fluid concentrations that may be expected to engage extracellular aggregated α-synuclein in the brain. Findings support the design of an ongoing phase 2 clinical study (NCT03100149). Trial Registration: ClinicalTrials.gov Identifier: NCT02157714.

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.

A Phase Ib Randomized Controlled Study to Evaluate the Effectiveness of a Single-Dose of the NR2B Selective N-Methyl-D-Aspartate Antagonist MK-0657 on Levodopa-Induced Dyskinesias and Motor Symptoms in Patients With Parkinson Disease.

OBJECTIVES: Blockade of N-methyl-D-aspartate receptors containing the NR2B subunit has been shown to be therapeutic in animal models of Parkinson disease (PD). However, findings with investigational NR2B receptor antagonists in PD patients have been mixed. The objective of this study was to evaluate the effects of the NR2B selective N-methyl-D-aspartate receptor antagonist MK-0657 on levodopa-induced dyskinesias and motor symptoms in PD patients. METHODS: A randomized, double-blind, single-dose, 2-period crossover study was conducted in 22 patients with PD and levodopa-induced peak-dose dyskinesias. Patients received oral MK-0657 (7 mg) or placebo, in randomized order, on each of 2 test days. On both days, levodopa was administered as a 2-hour intravenous infusion at greater than or equal to 1 mg/kg per hour with frequent assessments of dyskinesia, motor function, and pharmacokinetics. RESULTS: MK-0657 7 mg had no significant effect on dyskinesias (difference versus placebo in modified Abnormal Involuntary Movement Scale mean change from baseline area under the curve over 5 hours, -2.3; 95% confidence interval, -5.1 to 0.4) or motor function (difference versus placebo in Unified Parkinson's Disease Rating Scale Part III mean change from baseline area under the curve over 5 hours, 13.9; 95% confidence interval, -1.7 to 29.5). MK-0657 7 mg achieved the target mean maximum plasma concentration of 400 nM. CONCLUSIONS: These data suggest that a single dose of MK-0657 7 mg is not effective in improving levodopa-induced dyskinesias and motor symptoms in PD patients. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov NCT00505843.

Digitizing Tablet and Fahn-Tolosa-Marín Ratings of Archimedes Spirals have Comparable Minimum Detectable Change in Essential Tremor.

BACKGROUND: Drawing Archimedes spirals is a popular and valid method of assessing action tremor in the upper limbs. We performed the first blinded comparison of Fahn-Tolosa-Marín (FTM) ratings and tablet measures of essential tremor to determine if a digitizing tablet is better than 0-4 ratings in detecting changes in essential tremor that exceed random variability in tremor amplitude. METHODS: The large and small spirals of FTM were drawn with each hand on two consecutive days by 14 men and four women (age 60±8.7 years [mean±SD]) with mild to severe essential tremor. The drawings were simultaneously digitized with a digitizing tablet. Tremor in each digitized drawing was computed with spectral analysis in an independent laboratory, blinded to the clinical ratings. The mean peak-to-peak tremor displacement (cm) in the four spirals and mean FTM ratings were compared statistically. RESULTS: Test-retest intraclass correlations (ICCs) (two-way random single measures, absolute agreement) were excellent for the FTM ratings (ICC 0.90, 95% CI 0.76-0.96) and tablet (ICC 0.97, 95% CI 0.91-0.99). Log10 tremor amplitude (T) and FTM were strongly correlated (logT=αFTM + ß, α≈0.6, ß≈-1.27, r=0.94). The minimum detectable change for the tablet and FTM were 51% and 67% of the initial assessment. DISCUSSION: Digitizing tablets are much more precise than clinical ratings, but this advantage is mitigated by the natural variability in tremor. Nevertheless, the digitizing tablet is a robust method of quantifying tremor that can be used in lieu of or in combination with clinical ratings.

Conversion to carbidopa and levodopa extended-release (IPX066) followed by its extended use in patients previously taking controlled-release carbidopa-levodopa for advanced Parkinson's disease.

BACKGROUND: IPX066 (Rytary®; carbidopa and levodopa [CD-LD] extended-release capsules) was designed to achieve therapeutic LD plasma concentrations within 1h of dosing and maintain LD concentrations for a prolonged duration in early or advanced Parkinson's disease (PD). METHODS: In this open-label study, patients underwent 6weeks of conversion to IPX066 from their prior controlled-release (CR)±immediate-release (IR) CD-LD therapy and 6months of maintenance (with an additional 6months of IPX066 at some sites). Clinical utility was assessed at both the end of conversion and maintenance. RESULTS: Among 43 patients initiated on IPX066, 33 completed conversion. The mean LD conversion ratio was 1.8 among 30 patients previously on CR plus IR (and 1.5 among 3 previously taking CR alone). The mean IPX066 dosing frequency was 3.5times/day compared with 2.6times/day for CR plus 4.6times/day for IR previously (and 4.7times/day for CR alone). By patient and clinician global improvement ratings after 6-month maintenance, ≥43.8% of patients were much or very much improved from their previous treatment, and ≥68.8% were at least minimally improved. Adverse events were consistent with those reported in prior IPX066 studies. CONCLUSIONS: These results suggest that advanced PD patients using CR CD-LD±IR can be safely converted to IPX066, with high likelihood of achieving a stable regimen, less frequent LD dosing, and improved overall clinical benefit. TRIAL REGISTRATION: Clinicaltrials.govNCT01411137.

The Effect of Gabapentin Enacarbil on Pain Associated with Moderate-to-Severe Primary Restless Legs Syndrome in Adults: Pooled Analyses from Three Randomized Controlled Trials.

BACKGROUND: Adults with moderate-to-severe primary restless legs syndrome (RLS) often experience painful dysesthesias, which may lead to impaired quality of life. OBJECTIVES: The aim of this study was to assess the effects of gabapentin enacarbil (GEn) on pain associated with moderate-to-severe primary RLS in adults. METHODS: Data were pooled from three double-blind, randomized, placebo-controlled, 12-week trials (NCT00298623, NCT00365352, NCT01332305) for adults receiving GEn or placebo once daily. Change in average daily RLS pain score and a combined International Restless Legs Scale (IRLS)-pain response were examined. RESULTS: The modified intention-to-treat population included 671 adults (placebo, n = 244; GEn 600 mg, n = 161; GEn 1200 mg, n = 266). Both GEn doses significantly improved average daily RLS pain score at week 12 (p < 0.001 for GEn 600 mg vs. placebo and GEn 1200 mg vs. placebo). The combined IRLS-pain response subanalysis included 366 patients with a baseline IRLS total score ≥15 and pain score ≥4 (placebo, n = 133; GEn 600 mg, n = 86; GEn 1200 mg, n = 147). Most patients were both IRLS and pain responders (placebo, 40 %; GEn 600 mg, 70 %; GEn 1200 mg, 67 %). Spearman rank correlations between IRLS total and pain score (change from baseline to week 12) were moderate or strong. The most frequent treatment-emergent adverse events were somnolence (placebo, 5 %; GEn 600 mg, 20 %; GEn 1200 mg, 23 %) and dizziness (placebo, 4 %; GEn 600 mg, 13 %; GEn 1200 mg, 22 %). CONCLUSIONS: This post hoc pooled analysis suggests that GEn (600 and 1200 mg) once daily significantly improved pain associated with moderate-to-severe primary RLS in adults; however, the analysis was not powered to detect statistical differences between the two GEn doses. Numerically, more GEn-treated patients had a combined IRLS-pain response than placebo-treated patients.

A randomized trial of inhaled levodopa (CVT-301) for motor fluctuations in Parkinson's disease.

BACKGROUND: Although levodopa is the most effective oral PD therapy, many patients experience motor fluctuations, including sudden loss of dose effect and delayed benefit. CVT-301 is a levodopa inhalation powder with the potential for rapid onset of action. The objective of this study was to evaluate CVT-301 self-administered by PD patients to relieve OFF episodes. METHODS: PD patients with ≥2 hours per day of OFF time despite oral levodopa ≥4 times per day were randomized to CVT-301 or placebo for 4 weeks, to be used up to 3 times per day for OFF episodes. After 2 weeks, the study-drug dose was escalated from 35 to 50 mg. The primary end point was mean change in UPDRS Part III score from a predose OFF state to the average of postdose scores obtained at 10, 20, 30, and 60 minutes, as assessed in-clinic at the end of week 4. Home diaries were recorded. RESULTS: Eighty-six patients used the study drug at an average frequency of 2.1 times per day for CVT-301 and for placebo. At 4 weeks, least-squares mean change in UPDRS Part III score favored CVT-301 by 7.0 points (P < 0.001). A treatment effect was evident at 10 minutes. At 4 weeks, least-squares mean OFF-time change from baseline favored CVT-301 by 0.9 hours per day (P = 0.045). The most frequently reported adverse events in the CVT-301 group were dizziness, cough, and nausea, each in 7% (3 of 43 patients). CONCLUSIONS: CVT-301 self-administered during OFF episodes provided rapid improvement of motor function, and daily OFF time was significantly reduced at the higher dose. CVT-301 was generally safe and well-tolerated. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Comparison of IPX066 with carbidopa-levodopa plus entacapone in advanced PD patients.

BACKGROUND: IPX066, an investigational extended-release carbidopa-levodopa (CD-LD) preparation, has demonstrated a rapid attainment and prolonged maintenance of therapeutic LD plasma concentrations in advanced Parkinson's disease (PD). This phase-3 crossover study assessed its efficacy and safety vs. CD-LD plus entacapone (CL + E). METHODS: At baseline, all patients had motor fluctuations despite a stable regimen of CL + E or CD-LD-entacapone combination tablets (CLE). The study included a 6-week conversion from CL + E or CLE to IPX066, followed by two 2-week, double-blind crossover treatment periods in randomized order, one on IPX066 (and placebo CL + E), the other on CL + E (and placebo IPX066), separated by 1-week open-label IPX066 treatment. The primary efficacy measure was mean percent daily "off" time during waking hours (from patient diaries). RESULTS: Of 91 randomized patients, 84 completed the study. Their median daily LD dosage was 1495 mg from IPX066 and 600 mg from CL + E, corresponding, after correction for bioavailability, to an approximately 22% higher LD exposure on IPX066. Compared with CL + E, IPX066 demonstrated a lower percent "off" time (24.0% vs. 32.5%; p < 0.0001), lower "off" time (3.8 vs. 5.2 h/day; p < 0.0001), and higher "on" time without troublesome dyskinesia (11.4 vs. 10.0 h/day; p < 0.0001). Other endpoints, including patient-reported treatment preference, also favored IPX066 (p < 0.05). During double-blind treatment, 20.2% and 13.6% of patients reported adverse events on IPX066 and CL + E, respectively. The most common were dyskinesia (4 patients), insomnia (3), and confusional state (3) for IPX066, and fall (2) for CL + E. CONCLUSIONS: In advanced PD, IPX066 showed improved efficacy, compared with CL + E, and appeared to be well tolerated.