The Choice Between Advanced Therapies for Parkinson's Disease Patients: Why, What, and When?

Advanced Parkinson's disease treatment patterns in Italy: an observational study interim analysis

BACKGROUND

Oral levodopa remains the mainstay of treatment for Parkinson's disease (PD). However, as PD progresses, response to treatment may fluctuate. Managing fluctuations can be demanding for clinicians and patients. There is a paucity of real-world studies reporting on PD management in patients with fluctuations in treatment response, especially in patients with advanced stages of PD. The multicentre, observational Parkinson's Disease Fluctuations treatment PAthway (PD-FPA) study describes the real-life management of response fluctuations in Italian patients with advanced PD.

PATIENTS AND METHODS

PD-FPA had a retrospective and prospective phase; herein, retrospective results are presented. Ten Italian centres enrolled patients with a PD diagnosis from 10-15 years prior to study entry (T0) and who had ≥2-year history of fluctuations. Data on patient demographics, medical history, PD stage, fluctuation characteristics, symptoms, and prescribed treatments were collected at T0 and retrospectively (2 years prior to T0) via patient chart review/interview.

RESULTS

Overall, 296 patients (60% male, mean age 68 years, 84% with Hoehn and Yahr scores 2-3) were enrolled. At T0, most patients (99.3%) were on oral levodopa therapy. All patients used dopaminergic medications; adjunctive medications included dopamine agonists (56%) and monoamine oxidase B (60%) and catechol-O-methyltransferase enzyme inhibitors (41%). At T0, 51% of patients had changed therapy, with response fluctuations being the most common reason (74%); wearing-off was the most common fluctuation (83%).

CONCLUSION

This interim analysis of PD-FPA suggests that adequate levodopa dosing and adjunctive medications can stabilize advanced PD and provide patients with a good quality of life.

Body image appearance in Parkinson's disease patients on device aided therapies

INTRODUCTION

Parkinson's disease patients may experience altered body image perception. Advanced Parkinson's disease (aPD) with motor complications often requires surgical and device-aided treatments (DAT), such as levodopa-carbidopa intestinal gel (LCIG) and deep brain stimulation (DBS). Understanding body image perception is crucial when managing these devices. This study aims to explore body image perception in aPD patients, hypothesizing a link between DAT and body image perception.

METHODS

We performed a cross-sectional study including non-demented aPD patients with and without DAT and age- and sex-matched controls. Participants were assessed using the Appearance Schemas Inventory-Revised (ASI-R), including Motivational Salience (MS) and Self-Evaluative Salience (SES) scores. Additional data included age, education, BMI, comorbidities, pharmacotherapy, and psychopathologies. PD patients were also evaluated with UPDRS, Hoehn and Yahr scales and LEDD calculation.

RESULTS

70 aPD and 36 controls were enrolled. No differences in ASI-R scores were found between PD patients and controls, but women with PD had significantly lower MS scores than controls (16.1 ± 5.6 vs 19.7 ± 5.8; p = 0.023). Among aPD patients, those on DAT had longer disease duration, higher Hoehn and Yahr, and lower UPDRS IV scores. The lowest MS was observed in women on LCIG (12.7 ± 3.3; p = 0.001).

DISCUSSION

This study shows low MS ratings driven by female gender and LCIG treatment. Women on LCIG show reduced attention and management of their appearance. This may be influenced by cultural, environmental, and biological factors. Prospective research is needed to understand the impact of DAT on body image.

Winding Back the Clock on Advanced Therapies: It's Time to Get Smart

Our language affects patients' perceptions of therapies. In Parkinson's disease, emergent response fluctuations and dyskinesias typically trigger conversations around commencing an "Advanced Therapy" which carries notions of Advanced Disease. The patient, resolute in their commitment to fighting the disease, is misled. Chasing reassurance that their disease has not yet progressed considerably; they may therefore resist a potentially life-changing therapy. Instead, we should offer a "Smart Therapy". This term more accurately and positively describes therapies on offer that stabilize response fluctuations and improve quality of life, without a focus on the negative connotations of progression to more advanced disease.

Mechanism and therapeutic targets of the involvement of a novel lysosomal proton channel TMEM175 in Parkinson's disease

Parkinson's disease (PD), recognized as the second most prevalent neurodegenerative disease in the aging population, presents a significant challenge due to the current lack of effective treatment methods to mitigate its progression. Many pathogenesis of PD are related to lysosomal dysfunction. Moreover, extensive genetic studies have shown a significant correlation between the lysosomal membrane protein TMEM175 and the risk of developing PD. Building on this discovery, TMEM175 has been identified as a novel potassium ion channel. Intriguingly, further investigations have found that potassium ion channels gradually close and transform into hydrion "excretion" channels in the microenvironment of lysosomes. This finding was further substantiated by studies on TMEM175 knockout mice, which exhibited pronounced motor dysfunction in pole climbing and suspension tests, alongside a notable reduction in dopamine neurons within the substantia nigra compacta. Despite these advancements, the current research landscape is not without its controversies. In light of this, the present review endeavors to methodically examine and consolidate a vast array of recent literature on TMEM175. This comprehensive analysis spans from the foundational research on the structure and function of TMEM175 to expansive population genetics studies and mechanism research utilizing cellular and animal models.A thorough understanding of the structure and function of TMEM175, coupled with insights into the intricate mechanisms underpinning lysosomal dysfunction in PD dopaminergic neurons, is imperative. Such knowledge is crucial for pinpointing precise intervention targets, thereby paving the way for novel therapeutic strategies that could potentially alter the neurodegenerative trajectory of PD.

[Unilateral thalamotomy with high intensity focal ultrasound in patients with refractory essential tremor: a comparative study between patients under and over 70 years of age]

INTRODUCTION

High intensity focal ultrasound (HIFU) thalamotomy is a novel treatment for refractory tremor. This study aims to compare the reduction in tremor intensity and adverse effects of treatment between patients younger and older than 70 years of age.

PATIENTS AND METHODS

All the patients with refractory essential tremor treated with HIFU between March 2021 and March 2023 were included consecutively. Various demographic and clinical variables were analysed, including age and the items on the Clinical Rating Scale for Tremor (CRST). Cerebral vascular pathology was quantified using the Fazekas scale. Outcomes and adverse effects were compared between the patients aged 70 years or younger, and those older than 70 years.

RESULTS

Ninety patients were included, and 50 of them were over 70 years old. Prior to treatment, the CRST A + B score was 20.4 ± 5.7 among those under 70 years of age, and 23.3 ± 5.1 in those older (p = 0.013). At six months after treatment, the mean was 3.8 ± 5.1 and 4.8 ± 4.5, respectively (p = 0.314). We found no significant differences in the CRST C score (2.8 ± 4.1 and 3.5 ± 4.8, p = 0.442). There were also no significant differences between the patients with vascular pathology (Fazekas = 1) and those without (4.6 ± 7.3 and 4.3 ± 4, p = 0.832). There were no differences in the presence of adverse effects between the groups based on age and vascular pathology.

CONCLUSIONS

Contrary to traditional opinion, older patients do not have a poorer response or a higher rate of adverse effects after HIFU treatment.

Levodopa-Carbidopa Intestinal Gel for Parkinson's Disease over 11 years: One Center's "Real-World" Experience

BACKGROUND

Levodopa-carbidopa intestinal gel (LCIG) therapy has been shown to be a safe and effective treatment for advanced Parkinson's disease (PD). Limited data are available regarding long-term benefits and complications in Canada. Objective of the study was to review long-term experience and clinical outcomes in PD patients with LCIG therapy over 11 years in a multidisciplinary University clinic setting.

METHODS

Chart review was done on PD patients with LCIG from 2011 to 2022. Data collected: dosing, UPDRS-III motor scores, OFF times, hours with dyskinesias, MoCA, complications, discontinuation reasons, and nursing time requirements.

RESULTS

Thirty-three patients received LCIG therapy with a mean follow-up of 3.25±2.09 years. UPDRS-III scores showed reduction of 15% from baseline (mean 35.9) up to 4 years (mean 30.4). Daily OFF time improved from baseline (mean 7.1 ± 3.13 hours) up to 5 years (mean 3.3 ± 2.31 hours; -53.5%; p < 0.048), and dyskinesias remained stable. Nursing time averaged 22 hours per patient per year after PEG-J insertion and titration. Most common complications were PEG-J tube dislodgement and stoma site infection (0-3zero to three events/patient/year). Serious side effects were seen in four (12%) patients resulting in hospitalization and/or death. Nine patients (27.2%) discontinued the treatment due to lack of improved efficacy over oral therapy or development of dementia and 10 (30%) died of causes unrelated to LCIG infusion.

CONCLUSION

Patients on LCIG showed improved motor function over 5-year follow-up. Serious complications were uncommon. Dedicated nursing time is required by LCIG-trained nurses in a multidisciplinary setting for optimum management.

Levodopa-Carbidopa-Entacapone Intestinal Gel in Advanced Parkinson Disease: A Multicenter Real-Life Experience

BACKGROUND

For Parkinson disease (PD) patients who have been diagnosed with advanced disease that can no longer be effectively controlled with optimized oral or transdermal medications, a range of device-aided therapies (DAT) are available, comprising either deep brain stimulation or infusion therapies providing continuous dopaminergic stimulation. Levodopa-entacapone-carbidopa intestinal gel (LECIG) infusion is the latest DAT for advanced PD (APD) that was approved in Romania in 2021.

STUDY QUESTION

What is the experience to date in real-world clinical practice in Romania regarding the efficacy and tolerability of LECIG in APD?

STUDY DESIGN

A retrospective evaluation of 74 APD patients treated with LECIG at 12 specialized APD centers in Romania.

MEASURES AND OUTCOMES

Demographic data and various clinical parameters were recorded, including Mini Mental State Evaluation score or Montreal Cognitive Assessment Test score. Levodopa-equivalent daily dose and the administered doses of levodopa and other PD medications were evaluated at baseline and after starting LECIG treatment. The efficacy of LECIG in reducing daily hours of off time, motor fluctuations, and dyskinesias were assessed. Any percutaneous endoscopic gastrojejunostomy system or device complications after starting LECIG treatment were noted.

RESULTS

At baseline, patients were taking oral levodopa for a mean of 5.3 times per day, with a high proportion also taking concomitant add-on therapies (dopamine agonists, 86%, monoamine oxidase type-B inhibitors, 53%; catechol-O-methyltransferase inhibitors, 64%). LECIG treatment significantly reduced daily off time versus baseline from 5.7 h/d to 1.7 hours per day ( P < 0.01). Duration and severity of dyskinesias was also significantly reduced versus baseline, and improvements were observed in Hoehn and Yahr Scale scores. LECIG treatment also allowed a significant reduction in the use of concomitant oral medications.

CONCLUSIONS

These findings suggest that LECIG treatment is an effective DAT option in APD that can simplify the treatment regimen.

Levodopa-Entacapone-Carbidopa Intestinal Gel in the Treatment of Advanced Parkinson's Disease: A Single Center Real-World Experience

Levodopa-entacapone-carbidopa intestinal gel infusion is a relatively new treatment option for advanced Parkinson's disease. We aimed to describe and analyze the characteristics of de novo levodopa-entacapone-carbidopa intestinal gel therapy in 20 consecutive patients with advanced Parkinson's disease. We assessed the profile of motor complications by evaluating the following: motor fluctuations, dyskinesias, and the freezing phenomenon at baseline (before the testing period) and before discharge. The treatment significantly reduced the duration of daily hours spent in off time compared with baseline pre-treatment values from a mean of 4.8 ± 0.9 h/day to a mean of 1.4 ± 0.5 h per day (p < 0.001). The duration and severity of peak-dose dyskinesia were also significantly reduced compared with baseline values. Out of the 10 patients who reported freezing, 8 did not present this complication at the pre-discharge assessment. Significant improvements were observed in Hoehn and Yahr scale scores in both the on and off states. The levodopa-entacapone-carbidopa intestinal gel therapy was well tolerated during the follow-up period immediately after initiation. Despite a relatively severe stage of the disease, all patients experienced a significant improvement in motor fluctuations, dyskinesias, and the freezing phenomenon.

Disease-specific interventions: The use of cell and gene therapies for Parkinson disease

Approaches to repair the brain around the loss of the nigrostriatal dopaminergic pathways in Parkinson disease (PD) are not new and have been attempted over many years. However, of late, the situation has moved forward in two main ways. In the case of cell therapies, the ability to make large numbers of authentic midbrain dopaminergic neuroblasts from human pluripotent stem cell sources has turned what was an interesting avenue of research into a major area of investment and trialing, by academics in conjunction with Pharma. In the case of gene therapies, their use around dopamine replacement has waned, as the interest in using them for disease modification targeting PD-specific pathways has grown. In this chapter, we discuss all these developments and the current status of cell and gene therapies for PD.

Continuous Subcutaneous Foslevodopa/Foscarbidopa in Parkinson's Disease: Safety and Efficacy Results From a 12-Month, Single-Arm, Open-Label, Phase 3 Study

INTRODUCTION

Foslevodopa/foscarbidopa, a soluble formulation of levodopa/carbidopa (LD/CD) prodrugs for the treatment of Parkinson's disease (PD), is administered as a 24-hour/day continuous subcutaneous infusion (CSCI) with a single infusion site. The efficacy and safety of foslevodopa/foscarbidopa versus oral immediate-release LD/CD was previously demonstrated in patients with PD in a 12-week, randomized, double-blind, phase 3 trial (NCT04380142). We report the results of a separate 52-week, open-label, phase 3 registrational trial (NCT03781167) that evaluated the safety/tolerability and efficacy of 24-hour/day foslevodopa/foscarbidopa CSCI in patients with advanced PD.

METHODS

Male and female patients with levodopa-responsive PD and ≥ 2.5 hours of "Off" time/day received 24-hour/day foslevodopa/foscarbidopa CSCI at individually optimized therapeutic doses (approximately 700-4250 mg of LD per 24 hours) for 52 weeks. The primary endpoint was safety/tolerability. Secondary endpoints included changes from baseline in normalized "Off" and "On" time, percentage of patients reporting morning akinesia, Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Parkinson's Disease Sleep Scale-2 (PDSS-2), 39-item Parkinson's Disease Questionnaire (PDQ-39), and EuroQol 5-dimension questionnaire (EQ-5D-5L).

RESULTS

Of 244 enrolled patients, 107 discontinued, and 137 completed treatment. Infusion site events were the most common adverse events (AEs). AEs were mostly nonserious (25.8% of patients reported serious AEs) and mild/moderate in severity. At week 52, "On" time without troublesome dyskinesia and "Off" time were improved from baseline (mean [standard deviation (SD)] change in normalized "On" time without troublesome dyskinesia, 3.8 [3.3] hours; normalized "Off" time, -3.5 [3.1] hours). The percentage of patients experiencing morning akinesia dropped from 77.7% at baseline to 27.8% at week 52. Sleep quality (PDSS-2) and quality of life (PDQ-39 and EQ-5D-5L) also improved.

CONCLUSION

Foslevodopa/foscarbidopa has the potential to provide a safe and efficacious, individualized, 24-hour/day, nonsurgical alternative for patients with PD.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier NCT03781167.

Nationwide Retrospective Analysis of Combinations of Advanced Therapies in Patients With Parkinson Disease

BACKGROUND AND OBJECTIVES

Advanced therapies (ATs; deep brain stimulation [DBS] or pump therapies: continuous subcutaneous apomorphine infusion [CSAI], levodopa/carbidopa intestinal gel [LCIG]) are used in later stages of Parkinson disease (PD). However, decreasing efficacy over time and/or side effects may require an AT change or combination in individual patients. Current knowledge about changing or combining ATs is limited to mostly retrospective and small-scale studies. The nationwide case collection Combinations of Advanced Therapies in PD assessed simultaneous or sequential AT combinations in Germany since 2005 to analyze their clinical outcome, their side effects, and the reasons for AT modifications.

METHODS

Data were acquired retrospectively by modular questionnaires in 22 PD centers throughout Germany based on clinical records and comprised general information about the centers/patients, clinical (Mini-Mental Status Test/Montréal Cognitive Assessment, Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale [MDS-UPDRS], side effects, reasons for AT modification), and therapeutical (ATs with specifications, oral medication) data. Data assessment started with initiation of the second AT.

RESULTS

A total of 148 AT modifications in 116 patients were associated with significantly improved objective (median decrease of MDS-UPDRS Part III 4.0 points [p < 0.001], of MDS-UPDRS Part IV 6.0 points [p < 0.001], of MDS-UPDRS Part IV-off-time item 1.0 points [p < 0.001]) and subjective clinical outcome and decreasing side effect rates. Main reasons for an AT modification were insufficient symptom control and side effects of the previous therapy. Subgroup analyses suggest addition of DBS in AT patients with leading dyskinesia, addition of LCIG for leading other cardinal motor symptoms, and addition of LCIG or CSAI for dominant off-time. The most long-lasting therapy-until requiring a modification-was DBS.

DISCUSSION

Changing or combining ATs may be beneficial when 1 AT is insufficient in efficacy or side effects. The outcome of an AT combination is comparable with the clinical benefit by introducing the first AT. The added AT should be chosen dependent on dominant clinical symptoms and adverse effects. Furthermore, prospective trials are needed to confirm the results of this exploratory case collection.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that, in patients with PD, changing or combining ATs is associated with an improvement in the MDS-UPDRS or subjective symptom reporting.

Access to device-aided therapies in advanced Parkinson's disease: navigating clinician biases, patient preference, and prognostic uncertainty

Device-aided therapies (DAT), which include deep brain stimulation and pump-based continuous dopaminergic stimulation with either levodopa or apomorphine, are among the major advances in the clinical management of Parkinson's disease (PD). Although DAT are being increasingly offered earlier in the disease course, their classical indication remains advanced PD. Theoretically, every patient should be offered transition to DAT when faced with refractory motor and nonmotor fluctuations and functional decline. Worldwide clinical reality is far from these ideal, and, therefore, question the "real-world" equal opportunity of access to DAT for PD patients with advanced PD-even within a single health care system. Differences in access to care, referral pattern (timing and frequency), as well as physician biases (unconscious/implicit or conscious/explicit bias), and patients' preferences or health-seeking behaviour are to be considered. Compared to DBS, little information is available concerning infusion therapies, as well as neurologists' and patients' attitudes towards them. This viewpoint aims to be thought-provoking and to assist clinicians in moving through the process of DAT selection, by including in their decision algorithm their own biases, patient perspective, ethical concerns as well as the current unknowns surrounding PD prognosis and DAT-related long-term side effects for a given patient.

Current and novel infusion therapies for patients with Parkinson's disease

Advanced Parkinson's disease is characterized by periods of poor mobility, dyskinesia and progressive decline in functional independence of the affected person despite the manipulation of levodopa doses and the introduction of supplemental therapies such as catechol-O-methyl transferase inhibitors, monoamine oxidase-B inhibitors and dopamine agonists. The implementation of drug delivery systems allows to bypass problems related to irregular and often unpredictable intestinal absorption of oral levodopa, which significantly affects its bioavailability and contributes to the development and persistence of motor complications. Subcutaneous apomorphine and levodopa/carbidopa jejunal infusion systems have been available for many years and their efficacy is confirmed by randomized studies and long-term experience in many centers worldwide. Recently, a new formulation of levodopa/carbidopa infusion gel that includes the catechol-O-methyl transferase inhibitor Entacapone has been introduced to the market. The use of entacapone allows to reduce total daily dose of administered levodopa. Two different soluble formulations of levodopa/carbidopa (ND0612 and ABBV-951) have completed clinical development, and both can ensure subcutaneous delivery by a portable pump infusion system. ABBV-951 uses a foslevodopa/foscarbidopa formulation, both prodrugs to improve absorption and tolerability. Both systems provide effective improvement of motor complications and are likely to expand the therapeutic options in advanced patients. Future efforts should focus on the earlier detection of patients who are candidates for device-aided therapies, increasing appropriate referral and broadening the availability of these treatments globally.

New horizons in Parkinson's disease in older populations

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease. Ageing is considered to be the greatest risk factor for PD, with a complex interplay between genetics and the environment. With population ageing, the prevalence of PD is expected to escalate worldwide; thus, it is of utmost importance to reduce the burden of PD. To date, there are no therapies to cure the disease, and current treatment strategies focus on the management of symptoms. Older adults often have multiple chronic diseases and geriatric syndromes, which further complicates the management of PD. Healthcare systems and care models necessary to address the broad needs of older PD patients are largely unavailable. In this New Horizon article, we discuss various aspects of PD from an ageing perspective, including disease management. We highlight recent advancements in PD therapies and discuss new care models with the potential to improve patient's quality of life.

Parkinson's disease therapy: what lies ahead?

The worldwide prevalence of Parkinson's disease (PD) has been constantly increasing in the last decades. With rising life expectancy, a longer disease duration in PD patients is observed, further increasing the need and socioeconomic importance of adequate PD treatment. Today, PD is exclusively treated symptomatically, mainly by dopaminergic stimulation, while efforts to modify disease progression could not yet be translated to the clinics. New formulations of approved drugs and treatment options of motor fluctuations in advanced stages accompanied by telehealth monitoring have improved PD patients care. In addition, continuous improvement in the understanding of PD disease mechanisms resulted in the identification of new pharmacological targets. Applying novel trial designs, targeting of pre-symptomatic disease stages, and the acknowledgment of PD heterogeneity raise hopes to overcome past failures in the development of drugs for disease modification. In this review, we address these recent developments and venture a glimpse into the future of PD therapy in the years to come.

Off-time Treatment Options for Parkinson's Disease

Motor fluctuations (MF) are deemed by patients with Parkinson's disease (PD) as the most troublesome disease feature resulting from the increasing impairment in responsiveness to dopaminergic drug treatments. MF are characterized by the loss of a stable response to levodopa over the nychthemeron with the reappearance of motor (and non-motor) parkinsonian clinical signs at various moments during the day and night. They normally appear after a few years of levodopa treatment and with a variable, though overall increasing severity, over the disease course. The armamentarium of first-line treatment options has widened in the last decade with new once-a-daily compounds, including a catechol O-methyltransferase inhibitor - Opicapone-, two MAO-B inhibitors plus channel blocker - Zonisamide and Safinamide and one amantadine extended-release formulation - ADS5012. In addition to apomorphine injection or oral levodopa dispersible tablets, which have been available for a long time, new on-demand therapies such as apomorphine sublingual or levodopa inhaled formulations have recently shown efficacy as rescue therapies for Off-time treatment. When the management of MF becomes difficult in spite of oral/on-demand options, more complex therapies should be considered, including surgical, i.e. deep brain stimulation, or device-aided therapies with pump systems delivering continuous subcutaneous or intestinal levodopa or subcutaneous apomorphine formulation. Older and less commonly used ablative techniques (radiofrequency pallidotomy) may also be effective while there is still scarce data regarding Off-time reduction using a new lesional approach, i.e. magnetic resonance-guided focused ultrasound. The choice between the different advanced therapies options is a shared decision that should consider physician opinion on contraindication/main target symptom, patients' preference, caregiver's availability together with public health systems and socio-economic environment. The choice of the right/first add-on treatment is still a matter of debate as well as the proper time for an advanced therapy to be considered. In this narrative review, we discuss all the above cited aspects of MF in patients with PD, including their phenomenology, management, by means of pharmacological and advanced therapies, on-going clinical trials and future research and treatment perspectives.

Effective Management of "OFF" Episodes in Parkinson's Disease: Emerging Treatment Strategies and Unmet Clinical Needs

Motor complications related to the chronic administration of levodopa and failure to prevent the neurodegenerative disease process counterbalance the pivotal discovery of levodopa as the cornerstone of PD treatment. Excellent motor control is offered early during the course of treatment, but this diminishes as pathological changes in the striatum lead to synaptic dopamine levels becoming completely dependent on exogenous dopamine. This non-physiologic stimulation of dopamine receptors eventually manifests as OFF episodes. As no disease modifying therapy exists for PD that can disrupt these pathological changes, most research and treatment focuses on optimization of dopaminergic stimulation of striatal receptors so that they mimic tonic, physiologic stimulation as closely as possible. Strategies focusing on these challenges have included non-pharmacologic approaches, optimizing levodopa pharmacokinetics, using adjunctive treatments including those with non-dopaminergic mechanisms, and implementing rescue therapies. Device aided therapies, including surgery, are also available. In this review, we will focus on effective management of motor symptoms related to OFF periods, including emerging strategies. Unmet clinical needs will be discussed, including non-motor symptoms, targeted molecular therapies and disease modifying therapy.

Infusion Therapies in the Treatment of Parkinson's Disease

Oral levodopa is the gold-standard therapy for treating Parkinson's disease (PD) but after a few years of treatment the therapeutic window narrows, and patients often experience various treatment-related complications. Patients in this advanced PD stage may benefit from alternative therapy, such as continuous intrajejunal delivery of levodopa-carbidopa intestinal gel (LCIG; or carbidopa-levodopa enteral suspension), continuous intrajejunal delivery of levodopa-carbidopa-entacapone intestinal gel, or continuous subcutaneous apomorphine infusion. Consideration and initiation of infusion therapies in advanced PD are suggested before the onset of major disability. The present review summarizes clinical evidence for infusion therapy in advanced PD management, discusses available screening tools for advanced PD, and provides considerations around optimal use of infusion therapy.

The dilemma between milestones of progression versus clinical scales in Parkinson's disease

There are significant challenges in accurately documenting the progression of Parkinson's disease (PD). The disease course is highly heterogeneous, there are no validated biomarkers, and we are reliant on repeated clinical measures to assess disease state over time. Yet, the ability to chart disease progression accurately is vital in both observational and interventional study designs, where reliable measures are critical to determine whether an outcome has been met. In this chapter, we first discuss the natural history of PD, including the spectrum of clinical presentation and expected developments through the course of the disease. We then explore in detail the current strategies for measuring disease progression, which can be broadly divided into: (i) the use of quantitative clinical scales; and (ii) determination of the onset time of key milestones. We discuss the strengths and limitations of these approaches for use in clinical trials, with a particular focus on disease modification trials. The selection of outcome measures for a particular study will depend on multiple factors, but trial duration is an important determinant. Milestones are reached over a course of years rather than months, and hence clinical scales with sensitivity to change are needed for short-term studies. However, milestones represent important markers of disease stage which are not confounded by symptomatic therapies and are of critical relevance to the patient. Prolonged but low intensity follow-up beyond a limited period of treatment with a putative disease-modifying agent may allow milestones to be incorporated into evaluation of efficacy in a practical and cost-effective way.

Pharmacological management of Parkinson's disease motor symptoms: update and recommendations from an expert

INTRODUCTION

Parkinson's disease (PD) is a neurodegenerative multisystemic disorder that affects approximately 1% of the population over 55 years old, with the mean age of onset at 60 years old, and the prevalence of the disease constantly growing.

DEVELOPMENT

PD is a progressive disease characterized by motor and non-motor symptoms that compromise patients' daily activities. It has a variable profile of onset and clinical evolution. Although currently available treatments have failed to clinically demonstrate neuroprotective properties, most motor symptoms are acceptably managed with dopaminergic medication. More than 50 years after launching levodopa, it remains the most effective treatment of motor symptoms in PD, able to provide sustained benefit throughout the entire course of the disease. Nevertheless, after two to three years of treatment, certain fluctuations start to appear in motor and non-motor responses to different doses of levodopa. Early identification and treatment of these fluctuations have a strong positive impact on the quality of life of the patient. Frequently accompanied by involuntary movements, proper control of fluctuations requires periodical adjustments of the medication and expert supplementation with dopaminergic and non-dopaminergic adjuvants.

CONCLUSIONS

The main purpose of this work is to offer a practical, updated guideline for neurologists regarding the use of dopaminergic agents from the initial stages of PD. Special emphasis is placed on the critical period after the end of the 'honeymoon' phase when variations in the symptomatology presented by each patient appear, forcing re-adjustment of the medication to fit their individual needs.

Genetic architecture of Parkinson’s disease subtypes – Review of the literature

The heterogeneity of Parkinson’s disease (PD) has been recognized since its description by James Parkinson over 200 years ago. The complexity of motor and non-motor PD manifestations has led to many attempts of PD subtyping with different prognostic outcomes; however, the pathophysiological foundations of PD heterogeneity remain elusive. Genetic contributions to PD may be informative in understanding the underpinnings of PD subtypes. As such, recognizing genotype-phenotype associations may be crucial for successful gene therapy. We review the state of knowledge on the genetic architecture underlying PD subtypes, discussing the monogenic forms, as well as oligo- and polygenic risk factors associated with various PD subtypes. Based on our review, we argue for the unification of PD subtyping classifications, the dichotomy of studies on genetic factors and genetic modifiers of PD, and replication of results from previous studies.

Deep Brain Stimulation in the Treatment of Parkinson’s Disease

Parkinson’s disease (PD) is a common progressive neurodegenerative movement disorder. The cardinal feature of Parkinson's is neuronal degeneration causing a dopamine deficit in the brain which leads to a host of clinical features in the patient. However, consensus over specific clinical criteria for diagnosis remains to be established. Parkinson’s does not have a cure yet, but a variety of diagnostic and treatment protocols have been developed over the years with a primary focus on pharmacological therapy. Anti-parkinsonian drugs such as levodopa lose their efficacy over time and are needed in higher doses as the disease inevitably progresses. An alternative to pharmacological therapy is deep brain stimulation (DBS). Deep brain stimulation involves transcranial placement of unilateral or bilateral leads (wires) most commonly in the sub-thalamic nucleus or the globus pallidus interna of the brain by stereotactic surgery. Given the multiple hypotheses explaining the different effects of DBS with sometimes conflicting mechanisms, it is difficult to pinpoint the exact way in which DBS operates. Nevertheless, it has proven to be significantly effective. DBS, although being a cost-effective treatment measure for Parkinson's patients, is not without limitations. A careful selection of patients is required preoperatively that determines the response and tolerance to the therapy in patients. This review aims to summarize the current literature on DBS in Parkinson's with a focus on the hypothesized mechanisms, selection criteria, advantages and its limitations.

Device-Assisted and Neuromodulatory Therapies for Parkinson's Disease: A Network Meta-Analysis

BACKGROUND

Device-assisted and neuromodulatory therapies are the standard of care for Parkinson's disease (PD) with disabling motor complications. We aimed to compare and rank the currently available advanced therapies for PD on patient relevant outcomes.

METHODS

We searched various databases for randomized controlled trials that studied subthalamic nucleus deep brain stimulation (STN-DBS), globus pallidus interna (GPi) DBS, pallidotomy, subthalamotomy, continuous subcutaneous apomorphine infusion (CSAI), or intrajejunal levodopa infusion (IJLI), in patients with PD and motor complications. Primary outcome was the quality of life (QOL) at 6 months. Secondary outcomes included Unified Parkinson's Disease Rating Scale III and II, ON time, OFF time, levodopa equivalent daily doses, and adverse events (AE). Data were pooled using a Bayesian network meta-analysis, summarized as mean difference (MD) with 95% credibility intervals (CrI) and visualized in forest plots/league tables. Surface under the cumulative ranking curve plots determined the ranking probability.

RESULTS

We identified 6745 citations and included 26 trials. STN-DBS (MD, -8.0; 95% CrI, -11, -5.8), GPi-DBS (MD, -7.1; 95% CrI, -11, -2.9), and IJLI (MD, -7.0; 95% CrI, -12, -1.8) led to better QOL than medical therapy alone, without significant differences among them. STN-DBS had the highest probability of being ranked the best treatment for QOL (79.6%), followed by IJLI (63.5%) and GPi-DBS (62.8%).

CONCLUSIONS

In advanced PD, STN-DBS alleviates more patient and clinician relevant outcomes, followed by GPi-DBS and IJLI. In resource limited settings, unilateral pallidotomy may improve motor symptoms and activities of daily living, although overall QOL may not be improved. © 2022 International Parkinson and Movement Disorder Society.

COMT Inhibitors in the Management of Parkinson's Disease

Levodopa treatment remains the gold standard for Parkinson's disease, but shortcomings related to the pharmacological profile, notably, oral administration and the consequent occurrence of motor complications, have led to the development of several add-on levodopa treatments or to research to improve the method of delivery. Motor fluctuations, and to a lesser extent non-motor fluctuations, concern half of the patients with Parkinson's disease after 5 years of disease and patients identified them as one of their most bothersome symptoms. Catechol-O-methyl transferase inhibitors (COMT-Is) are one of the recommended first-line levodopa add-on therapies for the amelioration of end-of dose motor fluctuations in patient with advanced Parkinson's disease. Currently, two peripheral COMT-Is are considered as first-line choices - entacapone (ENT), which was approved by the US Food and Drug Administration in 1999 and the European Committee in 1998; and opicapone (OPC), which was approved by the European Committee in 2016. A second-line COMT-I that requires regular hepatic monitoring, tolcapone (TOL), was approved by the Food and Drug Administration in 1998 and the European Committee in 1997. Of note, OPC also received Food and Drug Administration approval in 2021, but it is still only marketed in a few countries, including Germany, UK, Spain, Portugal, Italy, Japan, and USA, while ENT and TOL have a wider market. Our narrative review summarizes the pharmacokinetic/pharmacodynamic properties, clinical efficacy in terms of motor fluctuations, motor/non-motor symptoms, quality of life, and safety data of these three COMT-Is, as evidenced by randomized clinical trials, as well as by real-life observational studies. Overall, a phase III non-inferiority trial showed a similar effect between ENT and OPC on off-time (-60.8 min/day and -40.3 min/day, vs placebo, respectively), with a possible additional off-time reduction of 39 min/day, obtained when there is a switch from ENT to OPC. Concomitantly, TOL can reduce off-time by an average of 98 min/day. A significant though discrete concomitant reduction on the Unified Parkinson's Disease Rating Scale motor section (2-3 points) is obtained with all three drugs vs placebo. Data on quality of life are fewer and more heterogeneous, with positive results obtained especially in open-label studies. Effects on non-motor symptoms were investigated as secondary outcome only in a few studies, frequently by means of non-specific scales and a benefit was observed in open-label studies. Dopaminergic adverse effects were the most frequent, dyskinesia being the most common for the three drugs eventually requiring levodopa dose reductions. No urine discoloration and a very low incidence of diarrhea were found with OPC compared with ENT and TOL. Regular hepatic monitoring is needed only for TOL. A combination of COMT-Is with new formulations of levodopa, including the subcutaneous, intrajejunal, or new extended-release formulation, merits further exploration to improve the management of both mild and severe motor fluctuations.

Continuous subcutaneous apomorphine infusion in the early phase of advanced Parkinson's disease: A prospective study of 22 patients

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A prospective analysis of APO treatment of 22 PD patients in the initial stages of advanced PD.

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Motor and non-motor symptoms, cognitive function and quality of life were assessed over 6 months.

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APO resulted in significant improvements in motor function, but dyskinesia did not worsen.

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Overall non-motor symptom burden was reduced, and sleep/fatigue and mood improved with APO.

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APO also improved apathy, quality of life scores and executive functioning (attention, planning)

Introduction

Parkinson’s disease (PD) patients usually start treatment with apomorphine infusion (APO) in later stages of advanced PD (aPD). This timing limits the evaluation of its motor efficacy and other potential clinical benefits throughout the full course of aPD.

Methods

We prospectively analyzed the effect of APO on motor and non-motor symptoms, cognitive function and quality of life (QoL) in 22 PD patients with early stage aPD, defined as: age < 71 years and diagnosis of aPD for < 3 years.

Results

At baseline, mean (±SD) age and disease duration were 59.4 ± 6.1 and 8.7 ± 3.5 years, respectively. After 6 months of APO treatment, daily off-time decreased from 4.98 ± 2.37 to 1.48 ± 1.47 h (p ≤ 0.001) and UPDRS IV scores from 7.00 ± 2.58 to 5.32 ± 2.48 (p = 0.018). Dyskinesia did not worsen with APO despite an overall increase in levodopa equivalent daily dose. Mean NMSS scores improved with APO, from 52.50 ± 27.24 to 38.68 ± 27.17 (p = 0.002), with particular improvements in apathy and sleep quality. Mean PDQ-39 score was reduced with APO from 31.96 ± 11.93 to 19.27 ± 11.86 (p ≤ 0.001). Overall, cognition did not change after APO, while slight improvements were observed in executive functioning (attention and planning). All but one patient eventually underwent subthalamic deep brain stimulation.

Conclusion

In patients with early stage initial aPD, s substantial benefit of APO was observed on motor symptoms, driven by a 70% reduction in off-time versus baseline, superior to that observed in previous prospective studies. APO also improved frontal dysfunction in PD patients.

How Parkinson's patients in the USA perceive deep brain stimulation in the 21st century: Results of a nationwide survey

Research on attitudes regarding the use and timing of deep brain stimulation (DBS) has been mostly qualitative to this date. In this study, we aim to examine attitudes and perceptions about the use and timing of DBS in patients with Parkinson's disease (PD) who have not had DBS. We designed an online survey comprising Likert-type, multiple choice, and rank-order questions and distributed it to PD patients. We recruited participants via flyers, the Michael J. Fox Foundation Trial Finder, and the Parkinson Alliance website. We analyzed considerations for choosing or rejecting DBS and when participants would consider such a decision to be premature. Data were analyzed using descriptive and inferential statistics, including a multinomial logistic regression model. Among the 285 participants who reported not having undergone DBS, the most frequent concerns were related to the efficacy of DBS and not having exhausted medication alternatives. DBS was viewed as less convenient, effective, and safe when PD symptoms were still manageable by medication. Our regression model suggests that having fewer concerns over technical problems was a positive predictor of preferring early DBS, while concerns over DBS interfering with friendships and relationships was a negative predictor. Our results suggest that patients with PD who have not undergone DBS have a wide variety of attitudes regarding DBS and its timing. Given the increasing number of therapeutic options for PD, future work should compare perceptions and preferences regarding different PD treatment modalities to provide the best counseling for patients regarding their therapeutic options.

Autophagy-Lysosomal Pathway as Potential Therapeutic Target in Parkinson's Disease

Cellular quality control systems have gained much attention in recent decades. Among these, autophagy is a natural self-preservation mechanism that continuously eliminates toxic cellular components and acts as an anti-ageing process. It is vital for cell survival and to preserve homeostasis. Several cell-type-dependent canonical or non-canonical autophagy pathways have been reported showing varying degrees of selectivity with regard to the substrates targeted. Here, we provide an updated review of the autophagy machinery and discuss the role of various forms of autophagy in neurodegenerative diseases, with a particular focus on Parkinson's disease. We describe recent findings that have led to the proposal of therapeutic strategies targeting autophagy to alter the course of Parkinson's disease progression.

Lack of Association Between GBA Mutations and Motor Complications in European and American Parkinson's Disease Cohorts

Background:

Motor complications are a consequence of the chronic dopaminergic treatment of Parkinson’s disease (PD) and include levodopa-induced dyskinesia (LIDs) and motor fluctuations (MF). Currently, evidence is on lacking whether patients with GBA-associated PD differ in their risk of developing motor complications compared to the general PD population.

Objective:

To evaluate the association of GBA carrier status with the development of LIDS and MFs from early PD.

Methods:

Motor complications were recorded prospectively in 884 patients with PD from four longitudinal cohorts using part IV of the UPDRS or MDS-UPDRS. Subjects were followed for up to 11 years and the associations of GBA mutations with the development of motor complications were assessed using parametric accelerated failure time models.

Results:

In 439 patients from Europe, GBA mutations were detected in 53 (12.1%) patients and a total of 168 cases of LIDs and 258 cases of MF were observed. GBA carrier status was not associated with the time to develop LIDs (HR 0.78, 95%CI 0.47 to 1.26, p = 0.30) or MF (HR 1.19, 95%CI 0.84 to 1.70, p = 0.33). In the American cohorts, GBA mutations were detected in 36 (8.1%) patients and GBA carrier status was also not associated with the progression to LIDs (HR 1.08, 95%CI 0.55 to 2.14, p = 0.82) or MF (HR 1.22, 95%CI 0.74 to 2.04, p = 0.43).

Conclusion:

This study does not provide evidence that GBA-carrier status is associated with a higher risk of developing motor complications. Publication of studies with null results is vital to develop an accurate summary of the clinical features that impact patients with GBA-associated PD.

New approaches for developing multi-targeted drug combinations for disease modification of complex brain disorders. Does epilepsy prevention become a realistic goal?

Over decades, the prevailing standard in drug discovery was the concept of designing highly selective compounds that act on individual drug targets. However, more recently, multi-target and combinatorial drug therapies have become an important treatment modality in complex diseases, including neurodegenerative diseases such as Alzheimer's and Parkinson's disease. The development of such network-based approaches is facilitated by the significant advance in our understanding of the pathophysiological processes in these and other complex brain diseases and the adoption of modern computational approaches in drug discovery and repurposing. However, although drug combination therapy has become an effective means for the symptomatic treatment of many complex diseases, the holy grail of identifying clinically effective disease-modifying treatments for neurodegenerative and other brain diseases remains elusive. Thus, despite extensive research, there remains an urgent need for novel treatments that will modify the progression of the disease or prevent its development in patients at risk. Here we discuss recent approaches with a focus on multi-targeted drug combinations for prevention or modification of epilepsy. Over the last ~10 years, several novel promising multi-targeted therapeutic approaches have been identified in animal models. We envision that synergistic combinations of repurposed drugs as presented in this review will be demonstrated to prevent epilepsy in patients at risk within the next 5-10 years.

Combined and Sequential Treatment with Deep Brain Stimulation and Continuous Intrajejunal Levodopa Infusion for Parkinson's Disease

(1) Background: Deep brain stimulation (DBS) and continuous intrajejunal levodopa infusion (CLI) are efficacious treatments of medication related motor response fluctuations in advanced Parkinson's disease (PD). Literature regarding the use of both advanced treatments within one patient is scarce. (2) Methods: We present a retrospective single center case series and a review of the literature. Patients with PD who were treated with both DBS and CLI in our tertiary referral center between 2005 and 2020 were identified and medical records were assessed. Additionally, literature on patients treated with both therapies was systematically searched for in Medline and Embase. (3) Results: Nineteen patients were included. Medication related motor response fluctuations were a major indication for the second therapy in all but one. Of nine patients initially treated with DBS, five reported improvement with CLI. Seven of ten patients initially treated with CLI experienced benefits from DBS. The systematic literature search resulted in fifteen previous publications comprising 66 patients. Of the 59 patients, for whom the effect of the second treatment was known, 57 improved. (4) Conclusions: PD patients, who have persisting medication related motor response fluctuations, despite DBS or CLI treatment, may benefit from an additional or alternative treatment with either CLI or DBS.

Long-term effect of apomorphine infusion in advanced Parkinson's disease: a real-life study

Long-term effects of continuous subcutaneous apomorphine infusion (CSAI) on health-related quality of life (HRQoL) and predictors of CSAI discontinuation are poorly known. Data from consecutive advanced Parkinson’s disease patients treated in routine care were retrospectively collected over 24 months after CSAI initiation, with a focus on the 39-item Parkinson’s disease questionnaire (PDQ-39). We determined predictors of CSAI discontinuation and HRQoL improvement using multiple regression analysis. Of the 110 subjects evaluated over a 2-year period, 35% discontinued CSAI. Of those who continued treatment, HRQoL remained stable with a sustained reduction in motor fluctuations. The observed effect on dyskinesias was mild and transient. Of note, patients with preexisting impulse control disorders showed an overall good tolerability. PDQ-39 was the only baseline predictor of HRQoL improvement after 2 years of treatment. The presence of dyskinesias, poorer psychological status, shorter disease duration, male sex, and worse OFF state were predictors of discontinuation. Best candidates for CSAI are patients with: (i) poor baseline HRQoL and (ii) marked motor fluctuations.

Balancing Expectations for Success in Stem Cell-Based Clinical Trials for Parkinson's Disease

Upcoming clinical trials assessing transplantation of stem cell-derived dopaminergic neurons into the striatum in patients with Parkinson's disease could generate groundbreaking results on neuronal replacement in the human brain. However, as highlighted here, the road toward a clinically competitive treatment for this multisystem disorder will probably be long and winding.

Parkinson's disease advanced therapies - A systematic review: More unanswered questions than guidance

In advanced Parkinson's disease (PD), therapeutic interventions include device-aided therapies such as continuous subcutaneous apomorphine infusion (CSAI), levodopa-carbidopa intestinal gel (LCIG) infusion, and deep brain stimulation (DBS). We reappraised the evidence guiding the decision of appropriate device-aided therapies in advanced PD, and systematically reviewed the literature (including ongoing clinical trials) comparing CSAI, LCIG, DBS in terms of efficacy and cost-effectiveness, with particular consideration to possible conflicts of interests. Of 14,980 documents screened, sixteen were included (4 and 13 studies examining efficacy and cost-effectiveness, respectively). LCIG and DBS showed higher efficacy compared to best medical therapy (BMT). DBS was more expensive than BMT and LCIG. Lifetime costs of CSAI were lower of those of DBS, and DBS lifetime costs were lower than those of LCIG. The majority of studies (11 out of 16) showed direct or indirect sponsorship from pharmaceutical or device companies. Only one ongoing clinical trial comparing LCIG with DBS was found. Device-aided therapies address unmet needs in advanced PD. LCIG and DBS are superior to BMT in head-to-head studies; however, initial and lifetime costs should be considered when choosing those therapies. Guidelines to assist clinicians and patients to choose device-aided therapies, free from conflict of interests, are required.

Remote neurostimulation with physical fields at cellular level enabled by nanomaterials: Toward medical applications

Most neurological diseases have no cure today; innovations in neurotechnology are in urgent need. Nanomaterial-based remote neurostimulation with physical fields (NNSPs) is an emerging class of neurotechnologies that has generated tremendous interest in recent years. This perspective focuses on the clinical translation of this new class of neurotechnologies, an issue that so far has not received enough attention. We outline the major barriers in their clinical translation. We highlight our recent efforts to tackle these translational barriers, with a focus on the biological delivery problem. In particular, for the first time, we have shown that it is feasible to use noninvasive brain delivery to generate significant physiological responses in living animals by NNSP. However, much more work is needed to overcome the translational barriers.

Patient-Derived Induced Pluripotent Stem Cell-Based Models in Parkinson's Disease for Drug Identification

Parkinson's disease (PD) is a common progressive neurodegenerative disorder characterized by loss of striatal-projecting dopaminergic neurons of the ventral forebrain, resulting in motor and cognitive deficits. Despite extensive efforts in understanding PD pathogenesis, no disease-modifying drugs exist. Recent advances in cell reprogramming technologies have facilitated the generation of patient-derived models for sporadic or familial PD and the identification of early, potentially triggering, pathological phenotypes while they provide amenable systems for drug discovery. Emerging developments highlight the enhanced potential of using more sophisticated cellular systems, including neuronal and glial co-cultures as well as three-dimensional systems that better simulate the human pathophysiology. In combination with high-throughput high-content screening technologies, these approaches open new perspectives for the identification of disease-modifying compounds. In this review, we discuss current advances and the challenges ahead in the use of patient-derived induced pluripotent stem cells for drug discovery in PD. We address new concepts implicating non-neuronal cells in disease pathogenesis and highlight the necessity for functional assays, such as calcium imaging and multi-electrode array recordings, to predict drug efficacy. Finally, we argue that artificial intelligence technologies will be pivotal for analysis of the large and complex data sets obtained, becoming game-changers in the process of drug discovery.