Patterns and Determinants of Prescribing for Parkinson's Disease: A Systematic Literature Review

Amantadine use in the French prospective NS-Park cohort

OBJECTIVE

To assess amantadine use and associated factors in the patients with Parkinson's disease (PD).

BACKGROUND

Immediate-release amantadine is approved for the treatment of PD and is largely used in clinical practice to treat "levodopa-induced dyskinesia (LIDs). Its use varies according to countries and PD stages. The prospective NS-Park cohort collects features of PD patients followed by 26 French PD Expert Centres.

METHODS

Variables used for the analyses included demographics, motor and non-motor PD symptoms and motor complications [motor fluctuations (MFs), LIDs)], antiparkinsonian pharmacological classes and levodopa equivalent daily dose (LEDD). We evaluated: (i) prevalence of amantadine use and compared clinical features of amantadine users vs. non-users (cross-sectional analysis); (ii) factors associated with amantadine initiation (longitudinal analysis); (iii) amantadine effect on LIDs, MFs, apathy, impulse control disorders and freezing of gait (Fog) (longitudinal analysis).

RESULTS

Amantadine use prevalence was 12.6% (1,585/12,542, median dose = 200 mg). Amantadine users were significantly younger, with longer and more severe PD symptoms, greater LEDD and more frequent use of device-aided/surgical treatment. Factors independently associated with amantadine initiation were younger age, longer PD duration, more frequent LIDs, MFs and FoG, higher LEDD and better cognitive function. 9 of the 658 patients on amantadine had stopped it at the following visit, after 12-18 months (1.3%). New users of amantadine presented a higher improvement in LIDs and MF compared to amantadine never users.

CONCLUSIONS

About 12% of PD patients within the French NS-Park cohort used amantadine, mostly those with younger age and more severe PD. Amantadine initiation was associated with a subsequent reduction in LIDs and MFs.

The landscape of small-molecule prodrugs

Prodrugs are derivatives with superior properties compared with the parent active pharmaceutical ingredient (API), which undergo biotransformation after administration to generate the API in situ. Although sharing this general characteristic, prodrugs encompass a wide range of different chemical structures, therapeutic indications and properties. Here we provide the first holistic analysis of the current landscape of approved prodrugs using cheminformatics and data science approaches to reveal trends in prodrug development. We highlight rationales that underlie prodrug design, their indications, mechanisms of API release, the chemistry of promoieties added to APIs to form prodrugs and the market impact of prodrugs. On the basis of this analysis, we discuss strengths and limitations of current prodrug approaches and suggest areas for future development.

Dopaminergic treatment strategies for people with Parkinson's disease in Europe: a retrospective analysis of PRISM trial data

BACKGROUND

Levodopa (LD) is the most effective drug to treat Parkinson's disease (PD). The recently concluded multinational Parkinson's Real-World Impact Assessment (PRISM) trial revealed highly variable prescription patterns of LD monotherapy across six European countries. The reasons remain unclear.

METHODS

In this post hoc analysis of PRISM trial data, we used multivariate logistic regression analysis to identify socio-economic factors affecting prescription practice. We applied receiver-operated characteristics and split sample validation to test model accuracy to predict treatment class (LD monotherapy vs. all other treatments).

RESULTS

Subject age, disease duration, and country of residence were significant predictors of treatment class. The chance of receiving LD monotherapy increased by 6.9% per year of age. In contrast, longer disease duration reduced the likelihood of receiving LD monotherapy by 9.7% per year. Compared to the other countries, PD patients in Germany were 67.1% less likely and their counterparts in the UK 86.8% more likely to receive an LD monotherapy. The model classification accuracy of treatment class assignment was 80.1%. The area under the curve to predict treatment condition was 0.758 (95% CI [0.715, 0.802]). Split sample validation revealed poor sensitivity (36.6%), but excellent specificity (92.7%) to predict treatment class.

CONCLUSION

The relative lack of socio-economic variables affecting prescription practice in the study sample and limited model accuracy to predict treatment class suggest the presence of additional, country-specific factors affecting prescription patterns that were not assessed in the PRISM trial. Our findings indicate that physicians still avoid prescribing LD monotherapy to younger PD patients.

Prescribing patterns and determinants for elderly patients with Parkinson's disease in Japan: a retrospective observational study using insurance claims databases

Background

This study aimed to determine real-world prescribing patterns and determinants for Japanese patients with Parkinson's disease (PD), with a focus on patients ≥75 years.

Methods

This was a retrospective, observational, longitudinal study of patients with PD (≥30 years, ICD-10: G20 excluding Parkinson's syndrome) from three Japanese nationwide healthcare claim databases. Prescription drugs were tabulated using database receipt codes. Changes in treatment patterns were analyzed using network analysis. Factors associated with prescribing patterns and prescription duration were analyzed using multivariable analysis.

Results

Of 18 million insured people, 39,731 patients were eligible for inclusion (≥75-year group: 29,130; <75-year group: 10,601). PD prevalence was 1.21/100 people ≥75 years. Levodopa was the most commonly prescribed anti-PD drug (total: 85.4%; ≥75 years: 88.3%). Network analysis of prescribing patterns showed that most elderly patients switched from levodopa monotherapy to adjunct prescription patterns, as did younger patients, but with less complexity. Elderly patients who newly initiated PD treatment remained on levodopa monotherapy longer than younger patients; factors significantly associated with levodopa prescriptions were older age and cognitive impairment. Commonly prescribed adjunct therapies were monoamine oxidase type B inhibitors, non-ergot dopamine agonists, and zonisamide, regardless of age. Droxidopa and amantadine were prescribed as adjunct levodopa therapy slightly more frequently among elderly patients; levodopa adjunct therapy was prescribed when the levodopa dose was 300 mg, regardless of age.

Conclusion

Prescribing patterns for patients ≥75 years were levodopa centered and less complex than for those <75 years. Factors significantly associated with levodopa monotherapy and continued use of levodopa were older age and cognitive disorder.

Clinical trial registration

UMIN Clinical Trials Registry, https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000053425 (UMIN000046823).

Sustained response in early responders to safinamide in patients with Parkinson's disease and motor fluctuations: A post hoc analysis of the SETTLE study

Safinamide is a selective, reversible, monoamine oxidase B inhibitor for the treatment of patients with Parkinson's disease (PD) and motor fluctuations. This was a post hoc analysis of the SETTLE study, in which patients with PD and motor fluctuations were randomly assigned to 24-week treatment with safinamide (50 mg/day for 2 weeks, increased to 100 mg/day if tolerated) or placebo. In the present analysis, responders were defined according to their treatment responses at Week 2 and Week 24 based on changes in ON-time without troublesome dyskinesia from baseline with cutoffs of 1 hour. It was found that 81% (103/127) of the responders at Week 2 maintained the response through Week 24 in the safinamide group. Other outcomes did not necessarily coincide with the ON-time response; however, “Early” responders who showed a treatment response at both Week 2 and Week 24 had substantial improvements from baseline in OFF-time, UPDRS Part II and III scores, and PDQ-39 summary index scores through Week 24. The safinamide group had a higher proportion of early responders than the placebo group (39% vs 20%, p &lt; 0.0001). At baseline, early responders in the safinamide group had significantly higher UPDRS Part II and III scores, shorter ON-time, and longer OFF-time than the other responder populations. In conclusion, the results of the present post hoc analysis suggest that patients with a short ON-time, severe motor symptoms, and highly compromised activities of daily living can benefit from safinamide early in treatment and over the long term.

Time until modification of antiparkinsonian therapy in a group of patients from Colombia

INTRODUCTION

The aim was to determine the time elapsed between the start of treatment with antiparkinsonian agents and the modification of the pharmacological therapy, and to establish its related factors, in a group of patients with Parkinson's disease from Colombia.

PATIENTS AND METHODS

Retrospective cohort study that collected information about the treatment of patients with Parkinson's disease who started drug therapy between June, 2011 and December, 2013; a five-year follow-up was performed. Survival analyses for time to therapy modification were generated, and factors related to these changes were determined using Cox regression models.

RESULTS

A total of 3,224 patients (51.8% men) with a mean age of 73.1 ± 13.5 years started treatment with antiparkinsonian agents. After five years, 2,046 patients (63.5%) had modifications in drug therapy, in a mean time of 36.4 months (95% confidence interval: 35.7-37.1). A total of 1,216 patients (37.8%) required the addition of another active principle, while 830 (25.7%) had a switch to another drug. In the multivariate analysis, male sex, age over 65 years, and the start of amantadine were identified as factors that increased the likelihood of therapy modification. The use of bromocriptine, biperiden, and monotherapy as an initial treatment were associated with a reduction in this likelihood.

CONCLUSIONS

After five years of treatment, 63.5% of the patients with Parkinson's disease required modifications to their therapy, with a mean time of three years. Male sex, age over 65 years, and receiving initial therapy with amantadine affected the likelihood of switching therapy in these patients in Colombia.

Defining the unknowns for cell therapies in Parkinson's disease

First-in-human clinical trials have commenced to test the safety and efficacy of cell therapies for people with Parkinson's disease (PD). Proof of concept that this neural repair strategy is efficacious is based on decades of preclinical studies and clinical trials using primary foetal cells, as well as a significant literature exploring more novel stem cell-derived products. Although several measures of efficacy have been explored, including the successful in vitro differentiation of stem cells to dopamine neurons and consistent alleviation of motor dysfunction in rodent models, many unknowns still remain regarding the long-term clinical implications of this treatment strategy. Here, we consider some of these outstanding questions, including our understanding of the interaction between anti-Parkinsonian medication and the neural transplant, the impact of the cell therapy on cognitive or neuropsychiatric symptoms of PD, the role of neuroinflammation in the therapeutic process and the development of graft-induced dyskinesias. We identify questions that are currently pertinent to the field that require further exploration, and pave the way for a more holistic understanding of this neural repair strategy for treatment of PD.

Prescription Pattern of Monoamine Oxidase B Inhibitors Combined with Levodopa: A Retrospective Observational Analysis of Italian Healthcare Administrative Databases

BACKGROUND

Parkinson's disease is still incurable, and several factors are considered when defining pharmacological therapy.

OBJECTIVE

The aim of this study was to describe the prescription pattern of monoamine oxidase B inhibitors (MAO-BIs) marketed in Italy (selegiline, rasagiline, safinamide) as an add-on to levodopa among new users of MAO-BIs, from the perspective of the Italian National Health Service.

PATIENTS AND METHODS

Through cross-linkage of administrative healthcare data in the Ricerca e Salute (ReS) database, adults with a supply of one or more MAO-BIs in 2017, and with no other MAO-BI use since 2013, were selected. Levodopa had to be supplied within 30 days before/after the MAO-BI. The incidence, use, sex, age, comorbidities, 2-year prescription patterns (i.e., switches, proportion of treated patients per semester/year, mean daily milligrams/monthly tablets supplied, discontinuation, change to other anti-Parkinson drug) of patients taking MAO-BIs were provided.

RESULTS

In 2017, 1059 new users received an MAO-BI (incidence 22.6 × 100,000 adults) combined with levodopa: 502 subjects (10.7 × 100,000) were treated with selegiline, 161 (3.4 × 100,000) were treated with rasagiline, and 396 (8.4 × 100,000) were treated with safinamide. The cohorts mainly consisted of males with a median age of ≥ 74 years. Treatment incidences increased with age. Switches occurred in 18.0%, 11.0%, and 4.3% of the selegiline, rasagiline, and safinamide cohorts, respectively. Most of the patients switching from selegiline/safinamide changed to rasagiline, while most of the patients switching from rasagiline changed to safinamide. From the first to second years, patient numbers reduced by ≤ 50%, and the daily milligrams/monthly tablets slightly increased. Six-month discontinuation occurred in > 50% of all cohorts, and ≥ 65% of discontinuing patients changed to another anti-Parkinson drug.

CONCLUSIONS

This analysis described the heterogeneous use of MAO-BIs as an add-on to levodopa in Italy. Further clinical trials and real-world studies are encouraged to update the few existing guidelines and to align clinical practice strategies.

Questions in the Chemical Enzymology of MAO

We have structure, a wealth of kinetic data, thousands of chemical ligands and clinical information for the effects of a range of drugs on monoamine oxidase activity in vivo. We have comparative information from various species and mutations on kinetics and effects of inhibition. Nevertheless, there are what seem like simple questions still to be answered. This article presents a brief summary of existing experimental evidence the background and poses questions that remain intriguing for chemists and biochemists researching the chemical enzymology of and drug design for monoamine oxidases (FAD-containing EC 4.1.3.4).

Factors affecting the choice of first-line therapy in Parkinson's disease patients in Wales: A population-based study

First line treatment for Parkinson’s disease (PD) is typically either L-dopa or a non-ergot dopamine agonist (DA). However, the options for the treatment of motor symptoms in PD patients have increased in the last thirty years, which have seen several new classes of PD medications introduced onto the market. The purpose of this study is to examine the changes in first line therapy of newly diagnosed Parkinson’s patients between 2000 and 2016 in Wales.

A population-based study evaluated data from the Secure Anonymised Information Linkage (SAIL) Databank of residents in Wales, aged 40 years or older, newly treated with PD medications between 2000 and 2016. The data was compared across three intervals: 2000–2005, 2006–2011 and 2012–2016. Patients were classified by age at diagnosis into young: 40–60 years; mid, 61–80 years; and older >80 years. Logistic regression was undertaken to determine the predictors of PD medication prescribing.

For the whole study period, the profiles of 9142 newly diagnosed PD patients were analysed. L-dopa was the most common first line therapy (80.6%), followed by non-ergot DAs (12.9%) and monoamine oxidase B (MAO-B) inhibitors (7.9%). Odds of L-dopa prescribing were greater in patients >80 years (OR = 20.46 95%CI: 16.25–25.76) and in the period 2012–2016 (OR = 1.98 95% CI: 1.70–2.29). Prescribing of non-ergot DAs significantly declined in 2012–2016 (OR = 0.42 95% CI: 0.35–0.49). Additional factors influencing first line therapy were deprivation, presence of diabetes and prior use of antidepressants. For example, PD patients residing in the least deprived area were less likely to be prescribed L-dopa compared to patients residing in the most deprived area (OR = 0.77 95% CI: 0.65–0.93).

First line therapy in PD in Wales has undergone a significant switch towards L-dopa over the last 16 years. The data indicates reasonable compliance with guidelines on efficacy and safety issues related to Parkinson’s medications.

Comparison of effectiveness of trihexyphenidyl and levodopa on motor symptoms in Parkinson's disease

Despite anti-cholinergics being the oldest type of medication used for the treatment of Parkinson's disease (PD), the mechanism of action and exact benefit is unclear. This study compared the effectiveness of trihexyphenidyl (THP) and levodopa (LD) on motor symptoms in patients with PD. Patients with PD who are currently taking or had taken THP were recruited. UPDRS-III was done following overnight medication OFF state and 30 min, 60 min, 90 min, and 120 min after THP (4 mg). After a forty-eight-hour interval, UPDRS-III was assessed one hour after Levodopa/carbidopa (200/50 mg) in an overnight OFF state. Twenty patients with a mean age of 57.9 ± 7.8 years and mean duration of illness of 5.1 ± 3.6 years were recruited. UPDRS-III score reduction (%) with THP was maximum in the tremor sub-score (53.8 ± 22.8) and was significantly better compared to improvement in total-UPDRS-III (27.0 ± 14.7), bradykinesia-UPDRS-III (22.2 ± 27.2), rigidity-UPDRS-III (29.5 ± 28.0) and axial-UPDRS-III (8.1 ± 13.3) sub-score. In comparison, respective LD improvement was 67.1 ± 22.9 (tremor-UPDRS-III), 61.3 ± 14.4 (total-UPDRS-III), 67.9 ± 32.1 (bradykinesia-UPDRS-III), 65.3 ± 25.5 (rigidity-UPDRS-III) and 50.7 ± 16.0 (axial-UPDRS-III). Improvement (%) in tre-UPDRS-III post-THP was comparable to that of post-LD (53.8 ± 22.8 vs. 67.1 ± 22.9, p = 0.057). Those with same or better tremor response with THP had significantly milder baseline tremor severity than those who had better response with LD (tre-UPDRS-III-OFF, 10.0 ± 2.8 vs. 5.8 ± 4.0, p = 0.013). Both THP and LD showed significant improvement in UPDRS-III. With THP, the maximum degree of improvement was in the tremor sub-score and not significantly different to that obtained by LD. Those with better tremor response on THP had milder tremor severity.

Nuclear Factor-κB Dysregulation and α-Synuclein Pathology: Critical Interplay in the Pathogenesis of Parkinson's Disease

The loss of dopaminergic neurons of the nigrostriatal system underlies the onset of the typical motor symptoms of Parkinson's disease (PD). Lewy bodies (LB) and Lewy neurites (LN), proteinaceous inclusions mainly composed of insoluble α-synuclein (α-syn) fibrils are key neuropathological hallmarks of the brain of affected patients. Compelling evidence supports that in the early prodromal phases of PD, synaptic terminal and axonal alterations initiate and drive a retrograde degeneration process culminating with the loss of nigral dopaminergic neurons. This notwithstanding, the molecular triggers remain to be fully elucidated. Although it has been shown that α-syn fibrillary aggregation can induce early synaptic and axonal impairment and cause nigrostriatal degeneration, we still ignore how and why α-syn fibrillation begins. Nuclear factor-κB (NF-κB) transcription factors, key regulators of inflammation and apoptosis, are involved in the brain programming of systemic aging as well as in the pathogenesis of several neurodegenerative diseases. The NF-κB family of factors consists of five different subunits (c-Rel, p65/RelA, p50, RelB, and p52), which combine to form transcriptionally active dimers. Different findings point out a role of RelA in PD. Interestingly, the nuclear content of RelA is abnormally increased in nigral dopamine (DA) neurons and glial cells of PD patients. Inhibition of RelA exert neuroprotection against (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) MPTP and 1-methyl-4-phenylpyridinium (MPP+) toxicity, suggesting that this factor decreases neuronal resilience. Conversely, the c-Rel subunit can exert neuroprotective actions. We recently described that mice deficient for c-Rel develop a PD-like motor and non-motor phenotype characterized by progressive brain α-syn accumulation and early synaptic changes preceding the frank loss of nigrostriatal neurons. This evidence supports that dysregulations in this transcription factors may be involved in the onset of PD. This review highlights observations supporting a possible interplay between NF-κB dysregulation and α-syn pathology in PD, with the aim to disclose novel potential mechanisms involved in the pathogenesis of this disorder.