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Nature Reviews. Neurology Apr 2019Parkinson disease (PD) treatment options have conventionally focused on dopamine replacement and provision of symptomatic relief. Current treatments cause undesirable... (Review)
Review
Parkinson disease (PD) treatment options have conventionally focused on dopamine replacement and provision of symptomatic relief. Current treatments cause undesirable adverse effects, and a large unmet clinical need remains for treatments that offer disease modification and that address symptoms resistant to levodopa. Advances in high-throughput drug screening methods for small molecules, developments in disease modelling and improvements in analytical technologies have collectively contributed to the emergence of novel compounds, repurposed drugs and new technologies. In this Review, we focus on disease-modifying and symptomatic therapies under development for PD. We review cellular therapies and repurposed drugs, such as nilotinib, inosine, isradipine, iron chelators and anti-inflammatories, and discuss how their success in preclinical models has paved the way for clinical trials. We provide an update on immunotherapies and vaccines. In addition, we review non-pharmacological interventions targeting motor symptoms, including gene therapy, adaptive deep brain stimulation (DBS) and optogenetically inspired DBS. Given the many clinical phenotypes of PD, individualization of therapy and precision of treatment are likely to become important in the future.
Topics: Antiparkinson Agents; Deep Brain Stimulation; Genetic Therapy; Humans; Parkinson Disease
PubMed: 30867588
DOI: 10.1038/s41582-019-0155-7 -
Annals of Neurology Jul 2021The aim was to demonstrate that continuous s.c. infusion of a soluble levodopa (LD)/carbidopa (CD) phosphate prodrug combination effectively delivers stable LD exposure...
OBJECTIVE
The aim was to demonstrate that continuous s.c. infusion of a soluble levodopa (LD)/carbidopa (CD) phosphate prodrug combination effectively delivers stable LD exposure via a minimally invasive and convenient mode and has the potential to treat Parkinson's disease (PD) patients who are not well controlled on oral medication.
METHODS
Foslevodopa and foscarbidopa were prepared and the equilibrium solubility and chemical stability examined in aqueous media with different values of pH. Solutions of foslevodopa/foscarbidopa (ratios ranging from 4:1 to 20:1) were prepared by dissolving pH-adjusted lyophilized materials in water and infused s.c. in healthy volunteers for ≤72 hours. Frequent blood samples were collected to measure LD and CD exposure, and safety was monitored throughout the study.
RESULTS
Foslevodopa/foscarbidopa (ABBV-951) demonstrates high water solubility and excellent chemical stability near physiological pH, enabling continuous s.c. infusion therapy. After s.c. infusion, a stable LD pharmacokinetic (PK) profile was maintained for ≤72 hours, and the infusion was well tolerated.
INTERPRETATION
Preparation of foslevodopa and foscarbidopa enables preclinical and clinical PK, safety, and tolerability studies in support of their advancement for the treatment of PD. In phase 1 clinical trials, foslevodopa/foscarbidopa demonstrates consistent and stable LD plasma exposure, supporting further studies of this treatment as a potentially transformational option for those suffering from PD. ANN NEUROL 2021;90:52-61.
Topics: Antiparkinson Agents; Carbidopa; Drug Combinations; Humans; Levodopa; Parkinson Disease
PubMed: 33772855
DOI: 10.1002/ana.26073 -
Journal of Controlled Release :... Jun 2015Exosomes are naturally occurring nanosized vesicles that have attracted considerable attention as drug delivery vehicles in the past few years. Exosomes are comprised of...
Exosomes are naturally occurring nanosized vesicles that have attracted considerable attention as drug delivery vehicles in the past few years. Exosomes are comprised of natural lipid bilayers with the abundance of adhesive proteins that readily interact with cellular membranes. We posit that exosomes secreted by monocytes and macrophages can provide an unprecedented opportunity to avoid entrapment in mononuclear phagocytes (as a part of the host immune system), and at the same time enhance delivery of incorporated drugs to target cells ultimately increasing drug therapeutic efficacy. In light of this, we developed a new exosomal-based delivery system for a potent antioxidant, catalase, to treat Parkinson's disease (PD). Catalase was loaded into exosomes ex vivo using different methods: the incubation at room temperature, permeabilization with saponin, freeze-thaw cycles, sonication, or extrusion. The size of the obtained catalase-loaded exosomes (exoCAT) was in the range of 100-200nm. A reformation of exosomes upon sonication and extrusion, or permeabilization with saponin resulted in high loading efficiency, sustained release, and catalase preservation against proteases degradation. Exosomes were readily taken up by neuronal cells in vitro. A considerable amount of exosomes was detected in PD mouse brain following intranasal administration. ExoCAT provided significant neuroprotective effects in in vitro and in vivo models of PD. Overall, exosome-based catalase formulations have a potential to be a versatile strategy to treat inflammatory and neurodegenerative disorders.
Topics: Administration, Intranasal; Animals; Anti-Inflammatory Agents; Antioxidants; Antiparkinson Agents; Brain; Catalase; Chemistry, Pharmaceutical; Disease Models, Animal; Drug Carriers; Exosomes; Female; Kinetics; Mice; Mice, Inbred C57BL; Nanomedicine; Nanoparticles; Neurons; Neuroprotective Agents; Oxidative Stress; Oxidopamine; PC12 Cells; Parkinsonian Disorders; RAW 264.7 Cells; Rats; Solubility; Technology, Pharmaceutical
PubMed: 25836593
DOI: 10.1016/j.jconrel.2015.03.033 -
Current Neuropharmacology 2018Ever since the pioneering reports in the 60s, L-3,4-Dioxyphenylalanine (levodopa) has represented the gold standard for the treatment of Parkinson's Disease (PD).... (Review)
Review
BACKGROUND
Ever since the pioneering reports in the 60s, L-3,4-Dioxyphenylalanine (levodopa) has represented the gold standard for the treatment of Parkinson's Disease (PD). However, long-term levodopa (LD) treatment is frequently associated with fluctuations in motor response with serious impact on patient quality of life. The pharmacokinetic and pharmacodynamic properties of LD are pivotal to such motor fluctuations: discontinuous drug delivery, short half-life, poor bioavailability, and narrow therapeutic window are all crucial for such fluctuations. During the last 60 years, several attempts have been made to improve LD treatment and avoid long-term complications.
METHODS
Research and trials to improve the LD pharmacokinetic since 1960s are reviewed, summarizing the progressive improvements of LD treatment.
RESULTS
Inhibitors of peripheral amino acid decarboxylase (AADC) have been introduced to achieve proper LD concentration in the central nervous system reducing systemic adverse events. Inhibitors of catechol-O-methyltransferase (COMT) increased LD half-life and bioavailability. Efforts are still being made to achieve a continuous dopaminergic stimulation, with the combination of oral LD with an AADC inhibitor and a COMT inhibitor, or the intra-duodenal water-based LD/ carbidopa gel. Further approaches to enhance LD efficacy are focused on new non-oral administration routes, including nasal, intra-duodenal, intrapulmonary (CVT-301) and subcutaneous (ND0612), as well as on novel ER formulations, including IPX066, which recently concluded phase III trial.
CONCLUSION
New LD formulations, oral compounds as well as routes have been tested in the last years, with two main targets: achieve continuous dopaminergic stimulation and find an instant deliver route for LD.
Topics: Animals; Antiparkinson Agents; Humans; Levodopa; Parkinson Disease
PubMed: 28494719
DOI: 10.2174/1570159X15666170510143821 -
Journal of Parkinson's Disease 2021Long-term physiotherapy is acknowledged to be crucial to manage motor symptoms for Parkinson's disease (PD) patients, but its effectiveness is not well understood. (Meta-Analysis)
Meta-Analysis
BACKGROUND
Long-term physiotherapy is acknowledged to be crucial to manage motor symptoms for Parkinson's disease (PD) patients, but its effectiveness is not well understood.
OBJECTIVE
This systematic review and meta-analysis aimed to assess the evidence regarding the effectiveness of long-term physiotherapy to improve motor symptoms and reduce antiparkinsonian medication dose in PD patients.
METHODS
Pubmed, Cochrane, PEDro, and CINAHL were searched for randomized controlled trials before August 31, 2020 that investigated the effectiveness of physiotherapy for 6 months or longer on motor symptoms and levodopa-equivalent dose (LED) in PD patients with Hoehn and Yahr stage 1- 3. We performed random effects meta-analyses for long-term physiotherapy versus no/control intervention and estimated standard mean differences with 95% confidence intervals (CIs). Levels of evidence were rated by the Grading of Recommendation Assessment, Development and Evaluation approach.
RESULTS
From 2,940 studies, 10 studies involving 663 PD patients were assessed. Long-term physiotherapy had favorable effects on motor symptoms in off medication state [- 0.65, 95% CI - 1.04 to - 0.26, p = 0.001] and LED [- 0.49, 95% CI - 0.89to - 0.09, p = 0.02]. Subgroup analyses demonstrated favorable effects on motor symptoms in off medication state by aerobic exercise [- 0.42, 95% CI - 0.64 to - 0.20, p < 0.001] and LED by multidisciplinary rehabilitation of primarily physiotherapy [- 1.00, 95% CI - 1.44 to - 0.56, p < 0.001]. Quality of evidence for aerobic exercise and multidisciplinary rehabilitation were low and very low.
CONCLUSION
This review provided evidence that long-term physiotherapy has beneficial impact on motor symptoms and antiparkinsonian medication dose in PD patients and could motivate implementation of long-term physiotherapy.
Topics: Antiparkinson Agents; Humans; Levodopa; Parkinson Disease; Physical Therapy Modalities
PubMed: 34366377
DOI: 10.3233/JPD-212782 -
Movement Disorders : Official Journal... Nov 2022Inhibiting catechol-O-methyltransferase extends the plasma half-life of levodopa, potentially allowing physicians to optimize the levodopa regimen in patients with... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Inhibiting catechol-O-methyltransferase extends the plasma half-life of levodopa, potentially allowing physicians to optimize the levodopa regimen in patients with Parkinson's disease (PD) experiencing motor fluctuations.
OBJECTIVES
To evaluate the effects of once-daily opicapone on levodopa plasma pharmacokinetics and motor response when added to two different levodopa dosing regimens.
METHODS
A total of 24 patients with PD and motor fluctuations were enrolled in an exploratory, open-label, modified cross-over trial. Participants first received levodopa/carbidopa 500/125 mg (five intakes) for 2 weeks and were then randomly assigned (1:1) to levodopa/carbidopa 400/100 mg given over either four or five daily intakes plus opicapone 50 mg for an additional 2 weeks. Levodopa 12-hour pharmacokinetics was the primary outcome (ie, excluding the effect of last/evening levodopa/carbidopa intake), with motor complications evaluated as secondary outcomes.
RESULTS
Over 12-hour pharmacokinetics and compared with five-intake levodopa/carbidopa 500/125 mg without opicapone, maximal levodopa concentrations were similar or nonsignificantly higher on both levodopa/carbidopa 400/100 mg regimens plus opicapone. Despite a 100 mg lower total levodopa/carbidopa daily dose, adding opicapone 50 mg at least doubled the levodopa plasma half-life and minimal concentrations, with a significant ≈30% increase in total exposure. The levodopa fluctuation index was only significantly lower for the five intakes plus opicapone regimen (difference of -71.8%; P < 0.0001). Modifications to levodopa pharmacokinetics were associated with decreased off time and increased on time.
CONCLUSIONS
Combining opicapone 50 mg with a 100 mg lower daily dose of levodopa provides higher levodopa bioavailability with avoidance of trough levels. Despite the lower levodopa dose, modifying the levodopa pharmacokinetic profile with opicapone was associated with decreased off time and increased on time. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Topics: Humans; Antiparkinson Agents; Carbidopa; Catechol O-Methyltransferase; Catechol O-Methyltransferase Inhibitors; Levodopa; Parkinson Disease; Cross-Over Studies
PubMed: 36054562
DOI: 10.1002/mds.29193 -
CNS & Neurological Disorders Drug... 2024Currently, available therapeutics for the treatment of Parkinson's disease (PD) fail to provide sustained and predictable relief from motor symptoms without significant... (Review)
Review
Currently, available therapeutics for the treatment of Parkinson's disease (PD) fail to provide sustained and predictable relief from motor symptoms without significant risk of adverse events (AEs). While dopaminergic agents, particularly levodopa, may initially provide strong motor control, this efficacy can vary with disease progression. Patients may suffer from motor fluctuations, including sudden and unpredictable drop-offs in efficacy. Dopamine agonists (DAs) are often prescribed during early-stage PD with the expectation they will delay the development of levodopa-associated complications, but currently available DAs are less effective than levodopa for the treatment of motor symptoms. Furthermore, both levodopa and DAs are associated with a significant risk of AEs, many of which can be linked to strong, repeated stimulation of D2/D3 dopamine receptors. Targeting D1/D5 dopamine receptors has been hypothesized to produce strong motor benefits with a reduced risk of D2/D3-related AEs, but the development of D1-selective agonists has been previously hindered by intolerable cardiovascular AEs and poor pharmacokinetic properties. There is therefore an unmet need in PD treatment for therapeutics that provide sustained and predictable efficacy, with strong relief from motor symptoms and reduced risk of AEs. Partial agonism at D1/D5 has shown promise for providing relief from motor symptoms, potentially without the AEs associated with D2/D3-selective DAs and full D1/D5-selective DAs. Tavapadon is a novel oral partial agonist that is highly selective at D1/D5 receptors and could meet these criteria. This review summarizes currently available evidence of tavapadon's therapeutic potential for the treatment of early through advanced PD.
Topics: Humans; Dopamine Agonists; Parkinson Disease; Levodopa; Dopamine Agents; Receptors, Dopamine D2; Receptors, Dopamine D1; Antiparkinson Agents
PubMed: 36999711
DOI: 10.2174/1871527322666230331121028 -
Science (New York, N.Y.) Dec 2023Gain-of-function mutations in , which encodes the leucine-rich repeat kinase 2 (LRRK2), are the most common genetic cause of late-onset Parkinson's disease. LRRK2 is...
Gain-of-function mutations in , which encodes the leucine-rich repeat kinase 2 (LRRK2), are the most common genetic cause of late-onset Parkinson's disease. LRRK2 is recruited to membrane organelles and activated by Rab29, a Rab guanosine triphosphatase encoded in the locus. We present cryo-electron microscopy structures of Rab29-LRRK2 complexes in three oligomeric states, providing key snapshots during LRRK2 recruitment and activation. Rab29 induces an unexpected tetrameric assembly of LRRK2, formed by two kinase-active central protomers and two kinase-inactive peripheral protomers. The central protomers resemble the active-like state trapped by the type I kinase inhibitor DNL201, a compound that underwent a phase 1 clinical trial. Our work reveals the structural mechanism of LRRK2 spatial regulation and provides insights into LRRK2 inhibitor design for Parkinson's disease treatment.
Topics: Humans; Antiparkinson Agents; Catalytic Domain; Cryoelectron Microscopy; Drug Design; Gain of Function Mutation; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; Parkinson Disease; Protein Subunits; rab GTP-Binding Proteins; Protein Multimerization; Protein Kinase Inhibitors
PubMed: 38127736
DOI: 10.1126/science.adi9926 -
Advances in Nutrition (Bethesda, Md.) Dec 2021Although levodopa remains the most effective drug for symptomatic management of Parkinson's Disease (PD), treatment during advanced disease stages may raise...
Although levodopa remains the most effective drug for symptomatic management of Parkinson's Disease (PD), treatment during advanced disease stages may raise unpredictable motor fluctuations and other complications. Counteracting these complications with other pharmacological therapies may prompt a vicious circle of side effects, and here, nutritional therapy may have great potential. Knowledge about the role of diet in PD is emerging and multiple studies have investigated nutritional support specifically with respect to levodopa therapy. With this systematic review, we aim to give a comprehensive overview of dietary approaches to optimize levodopa treatment in PD. A systematic search was performed using the databases of PubMed and Scopus between January 1985 and September 2020. Nutritional interventions with the rationale to optimize levodopa therapy in human PD patients were eligible for this study and their quality was assessed with the Cochrane risk-of-bias tool. In total, we included 22 papers that addressed the effects of dietary proteins (n = 10), vitamins (n = 7), fiber (n = 2), soybeans (n = 1), caffeine (n = 1), and ketogenic diets (n = 1) on levodopa therapy. Interventions with protein redistribution diets (PRDs), dietary fiber, vitamin C, and caffeine improved levodopa absorption, thereby enhancing clinical response and reducing motor fluctuations. Furthermore, supplementation of vitamin B-12, vitamin B-6, and folic acid successfully reduced high homocysteine concentrations that emerged from levodopa metabolism and promoted many metabolic and clinical complications, such as neuropathology and osteoporosis. In conclusion, dietary interventions have the potential to optimize levodopa efficacy and control side effects. Nutrition that improves levodopa absorption, including PRDs, fiber, vitamin C, and caffeine, is specifically recommended when fluctuating clinical responses appear. Supplements of vitamin B-12, vitamin B-6, and folic acid are advised along with levodopa initiation to attenuate hyperhomocysteinemia, and importantly, their potential to treat consequent metabolic and clinical complications warrants future research.
Topics: Antiparkinson Agents; Diet; Humans; Levodopa; Parkinson Disease; Vitamin B 12
PubMed: 34113965
DOI: 10.1093/advances/nmab060 -
Journal of Parkinson's Disease 2021ND0612 is a continuous, subcutaneous levodopa/carbidopa delivery system in development for patients with Parkinson's disease (PD) experiencing motor... (Randomized Controlled Trial)
Randomized Controlled Trial
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.
Topics: Aged; Antiparkinson Agents; Carbidopa; Drug Combinations; Dyskinesia, Drug-Induced; Feasibility Studies; Female; Humans; Infusions, Parenteral; Levodopa; Male; Middle Aged; Outcome Assessment, Health Care; Parkinson Disease; Severity of Illness Index; Single-Blind Method
PubMed: 33164945
DOI: 10.3233/JPD-202285