Long-Term Effects of Safinamide on Dyskinesia in Mid- to Late-Stage Parkinson's Disease: A Post-Hoc Analysis

The Effects of Safinamide in Chinese and Non-Chinese Patients with Parkinson's Disease

INTRODUCTION

Ethnicity differences are an important determinant in the clinical manifestation of Parkinson's disease (PD), but they are not yet widely recognized, particularly regarding the response to dopaminergic medications. The aim of this paper is to analyze the efficacy and safety of safinamide in Chinese patients with PD in the pivotal studies SETTLE and XINDI compared to the non-Chinese population of the SETTLE trial.

METHODS

SETTLE (NCT00627640) and XINDI (NCT03881371) were phase III, randomized, double-blind, placebo-controlled, multicenter trials. Patients received safinamide or placebo as add-on to levodopa. The primary efficacy endpoint was the change in the mean total daily OFF time. Secondary efficacy endpoints included total daily ON time, ON time with no/non-troublesome dyskinesia, Unified Parkinson's Disease Rating Scale, and Parkinson's Disease Questionnaire-39 items. Safety was evaluated through the frequency of adverse events. Data from 440 non-Chinese and 109 Chinese patients in the SETTLE study, and 305 Chinese patients in the XINDI trial were considered for this post hoc analysis.

RESULTS

Significant positive results were seen in favor of safinamide in all populations for the primary and secondary endpoints, with no differences in terms of magnitude. No "treatment by ethnicity" interaction was detected for any parameters, confirming the homogeneity of treatment effects between different populations. The safety and tolerability of safinamide in Chinese patients were similar to those in the other ethnic groups, without unexpected adverse reactions.

CONCLUSIONS

Safinamide was shown to improve PD symptoms and quality of life in different ethnic populations, without any treatment by race interaction. Further studies are warranted to investigate potential differences in a real-life situation.

TRIAL REGISTRATION NUMBER

SETTLE (NCT00627640) and XINDI (NCT03881371).

Real-world use of Safinamide in motor fluctuating Parkinson's disease patients in Italy

INTRODUCTION

Safinamide is a recent antiparkinsonian drug that modulates both dopaminergic and glutamatergic systems with positive effects on motor and nonmotor symptoms of Parkinson's disease (PD). Here, we aimed to describe the efficacy and safety of safinamide in the Italian PD patients in real-life conditions.

METHODS

We performed a sub-analysis of the Italian cohort of the SYNAPSES study, a multi-country, multi-center, retrospective-prospective cohort observational study, designed to investigate the use of safinamide in routine clinical practice. Patients received for the first time a treatment with safinamide and were followed up for 12 months. The analysis was conducted on the overall population and in subgroups of interest: i) patients > 75 years, ii) patients with relevant comorbidities and iii) patients affected by psychiatric symptoms.

RESULTS

Italy enrolled 616/1610 patients in 52 centers, accounting for 38% of the entire SYNAPSES cohort. Of the patients enrolled, 86.0% were evaluable at 12 months, with 23.3% being > 75 years, 42.4% with psychiatric conditions and 67.7% with relevant comorbidities. Safinamide was effective on motor symptoms and fluctuations as measured through the Unified PD rating scale III and IV scores, and on the total score, without safety issues in none of the subgroups considered.

CONCLUSION

The SYNAPSES data related to Italian patients confirms the good safety profile of safinamide even in special groups of patients. Motor fluctuations and motor impairment improved at the follow-up suggesting the significant role of safinamide in managing motor symptoms in PD patients.

Pharmacokinetic and Safety Study of Single and Multiple Oral Doses of Safinamide in Healthy Chinese Volunteers

This randomized, parallel-group study evaluated the plasma pharmacokinetic profile of safinamide in 24 healthy Chinese men and women, randomly assigned to receive 50 or 100 mg of safinamide as a single dose, followed, after a 7-day washout, by multiple doses once daily for 7 days. Plasma safinamide was determined up to 96 h after the first single dose (day 1) and the last multiple dose (day 14), and up to 24 h after the first multiple dose (day 8). Following single- and multiple-dose administration, peak concentrations were achieved at a median time of 1.5-2 h. Plasma exposure increased in a dose-proportional manner. After single dose, mean half-life was 23-24 h. Area under the concentration-time curve (AUC) from time zero extrapolated to infinity was only slightly higher than AUC from time zero to the last quantifiable concentration, corresponding for the 2 parameters, respectively, to 12,380 and 11,560 ng • h/mL for the 50 mg and to 22,030 and 20,790 ng • h/mL for the 100-mg dose. AUC in the dosing interval at steady state was 13,150 and 23,100 ng • h/mL for 50 and 100 mg of safinamide. Steady state was reached in 6 days, accumulation was approximately twofold, and the pharmacokinetics were time independent. The plasma safinamide pharmacokinetic profile observed in this study is in line with the published results in both Chinese and non-Asian populations.

SYNAPSES. A European observational study to evaluate the safety and the effectiveness of safinamide in routine clinical practice: post-hoc analysis of the Spanish study population

INTRODUCTION

Parkinson's Disease (PD) is a progressive age-related neurodegenerative condition requiring new therapeutic alternatives. Safinamide, a novel levodopa add-on therapy, positively affects disease fluctuations by modulating both dopaminergic and glutamatergic systems. To further investigate the use of safinamide in European routine clinical practice, the present post-hoc analysis aimed to understand safinamide's safety profile within the Spanish study population.

PATIENTS AND METHODS

Five hundred eleven Spanish patients with PD were evaluated at baseline, four (±1), eight (±1), and 12 (±1) months after initiating safinamide treatment. Unified Parkinson's Disease Rating Scale (UPDRS) total score and UPDRS part III score during on time were used to measure the overall severity of PD and motor complications, respectively, while the severity of adverse events was evaluated following the investigators' criteria.

RESULTS

Safinamide showed a favourable safety profile within the Spanish study population, although prescription to patients with psychiatric conditions and off-label use were more frequent than in the European study population. In Spain, clinically meaningful improvements were observed in UPDRS scores when safinamide was used as the only add-on therapy to levodopa (57.4% and 53.7% of patients) and when switching from rasagiline (55.1% of patients). Motor complications were reduced from 83.2% to 63.3% after the study period. Increased safety concerns were undetected in any patient subgroup, although patients with cognitive impairment showed a slightly higher frequency of adverse events.

CONCLUSIONS

This subanalysis further supports safinamide use as a safe and efficacious option for the management of motor fluctuations in different subgroups of levodopa-treated patients. However, safinamide should be used with caution in patients with cognitive impairment.

Clinical benefit of MAO-B and COMT inhibition in Parkinson's disease: practical considerations

Inhibitors of monoamine oxidase B (MAO-B) and catechol-O-methyltransferase (COMT) are major strategies to reduce levodopa degradation and thus to increase and prolong its effect in striatal dopaminergic neurotransmission in Parkinson's disease patients. While selegiline/rasagiline and tolcapone/entacapone have been available on the market for more than one decade, safinamide and opicapone have been approved in 2015 and 2016, respectively. Meanwhile, comprehensive data from several post-authorization studies have described the use and specific characteristics of the individual substances in clinical practice under real-life conditions. Here, we summarize current knowledge on both medication classes, with a focus on the added clinical value in Parkinson's disease. Furthermore, we outline practical considerations in the treatment of motor fluctuations and provide an outlook on ongoing studies with MAO-B and COMT inhibitors.

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 < 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.

Recent Advances in Drug Therapy for Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative disease manifesting with motor and non-motor symptoms. Current treatment mainly relies on medication as a symptomatic therapy modulating neurotransmitters. Dopamine replacement therapy has been established, and levodopa is the gold standard for treatment of PD. However, the emergence of motor complications, such as a wearing-off phenomenon, is a clinical problem. Both primary symptoms and motor complications have been targets for the development of treatments for PD. Recent progression in the management of motor complications is supported by newly developed agents and advances in device and formulation technology to deliver drugs continuously. Elucidation of the pathophysiology of PD and the development of disease-modifying therapy that affects the underlying fundamental pathophysiology of the disease are also progressing. In this review, we introduce current knowledge on developments concerning medications for patients with PD.

Effectiveness and safety of safinamide in routine clinical practice in a Belgian Parkinson's disease population: an open-label, levodopa add-on study

BACKGROUND

Safinamide is a recent multimodal antiparkinsonian drug that inhibits monoamine oxidase B and modulates the glutamatergic system with positive effects on motor and nonmotor symptoms of Parkinson's disease (PD). This post-hoc analysis of the European SYNAPSES study provides first-time data on the use of safinamide in routine clinical practice in Belgium.

OBJECTIVE

To describe the efficacy and safety of safinamide in Belgian PD patients in real-life conditions.

METHODS

Post-hoc analysis of the Belgian cohort from the European SYNAPSES trial, which was an observational, multicenter, retrospective-prospective cohort study. Patients were followed up to 12 months. Analyses were performed in the overall population and according to different criteria such as the age limit (> 75 years), presence or absence of relevant comorbidities, presence or absence of psychiatric conditions such as depression and anxiety, patients on levodopa monotherapy or levodopa in combination with other treatments, patients on rasagiline before inclusion or not.

RESULTS

Of the 172 patients included, 29.2% were > 75 years, 58.9% had relevant comorbidities and 32.7% had psychiatric conditions. Almost all the patients reported motor (98.8%) or non-motor (86.3%) symptoms. During the study, 36.3% of patients reported drug-related reactions. The adverse drug reactions were those already described in the patients' information leaflet. The majority were mild or moderate and completely resolved and no differences were detected between the subgroups of patients. Almost 35% of the patients demonstrated a clinically significant improvement in the UPDRS and 50% of the patients with wearing-off at baseline, did not report wearing-off anymore after one year of treatment. Patients under levodopa monotherapy compared to patients receiving levodopa combined with other antiparkinsonian treatments benefit more from safinamide treatment. Patients switched from rasagiline to safinamide seemed also to benefit more from safinamide treatment.

CONCLUSION

The study confirms the excellent safety and efficacy profile of safinamide, particularly in more vulnerable groups of patients such as the elderly and patients with significant comorbidities or psychiatric conditions such as depression or anxiety.

Long-term effects of safinamide adjunct therapy on levodopa-induced dyskinesia in Parkinson's disease: post-hoc analysis of a Japanese phase III study

This post-hoc analysis investigated the long-term effects of safinamide on the course of dyskinesia and efficacy outcomes using data from a phase III, open-label 52-week study of safinamide 50 or 100 mg/day in Japanese patients with Parkinson’s disease (PD) with wearing-off. Patients (N = 194) were grouped using the UPDRS Part IV item 32: with and without pre-existing dyskinesia (pre-D subgroup; item 32 > 0 at baseline [n = 81], without pre-D subgroup; item 32 = 0 at baseline [n = 113]). ON-time with troublesome dyskinesia (ON-TD) increased significantly from baseline to Week 4 in the pre-D subgroup (+ 0.25 ± 0.11 h [mean ± SE], p = 0.0355) but gradually decreased up to Week 52 (change from baseline: − 0.08 ± 0.17 h, p = 0.6224); ON-TD did not change significantly in the Without pre-D subgroup. UPDRS Part IV item 32 score increased significantly at Week 52 compared with baseline in the Without pre-D subgroup, but no UPDRS Part IV dyskinesia related-domains changed in the pre-D subgroup. Both subgroups improved in ON-time without TD, UPDRS Part III, and Part II [OFF-phase] scores. The cumulative incidence of new or worsening dyskinesia (adverse drug reaction) at Week 52 was 32.5 and 5.0% in the pre-D and Without pre-D subgroups, respectively. This study suggested that safinamide led to short-term increasing dyskinesia but may be not associated with marked dyskinesia at 1-year follow-up in patients with pre-existing dyskinesia, and that it improved motor symptoms regardless of the presence or absence of dyskinesia at baseline. Further studies are warranted to investigate this association in more details.

Trial registration: JapicCTI-153057 (Registered: 2015/11/02).

Effects of MAO-B inhibitors on non-motor symptoms and quality of life in Parkinson's disease: A systematic review

Non-motor symptoms (NMS) are common among patients with Parkinson's disease and reduce patients' quality of life (QOL). However, there remain considerable unmet needs for NMS management. Three monoamine oxidase B inhibitors (MAO-BIs), selegiline, rasagiline, and safinamide, have become commercially available in many countries. Although an increasing number of studies have reported potential beneficial effects of MAO-BIs on QOL and NMS, there has been no consensus. Thus, the primary objective of this study was to provide an up-to-date systematic review of the QOL and NMS outcomes from the available clinical studies of MAO-BIs. We conducted a literature search using the PubMed, Scopus, and Cochrane Library databases in November 2021. We identified 60 publications relevant to this topic. Overall, rasagiline and safinamide had more published evidence on QOL and NMS changes compared with selegiline. This was likely impacted by selegiline being introduced many years prior to the field embarking on the study of NMS. The impact of MAO-BIs on QOL was inconsistent across studies, and this was unlikely to be clinically meaningful. MAO-BIs may potentially improve depression, sleep disturbances, and pain. In contrast, cognitive and olfactory dysfunctions are likely unresponsive to MAO-BIs. Given the paucity of evidence and controlled, long-term studies, the effects of MAO-BIs on fatigue, autonomic dysfunctions, apathy, and ICD remain unclear. The effects of MAO-BIs on static and fluctuating NMS have never been investigated systematically. More high-quality studies will be needed and should enable clinicians to provide personalized medicine based on a non-motor symptom profile.

Safinamide in the treatment pathway of Parkinson's Disease: a European Delphi Consensus

Safinamide is a highly selective, reversible MAO B-inhibitor recently marketed in European and North American countries. To better define clinical indications regarding motor and non-motor symptoms, targeted population and safety of this compound, ten movement disorders specialists, experts in their field, convened and developed a panel of statements on: the role of glutamate in Parkinson's disease, introduction to fluctuations, efficacy of safinamide on motor symptoms, motor complications and non-motor symptoms, quality of life, safety of safinamide and target population for use. Strong consensus was reached for all the statements on the efficacy of safinamide on motor symptoms, motor fluctuations, quality of life and safety. Among non-motor symptoms, a positive consensus was reached for the symptoms sleep/fatigue, mood, and pain while there was a lack of consensus for the statements regarding the efficacy of safinamide in improving cognition, urinary and sexual functions. The statement on orthostatic hypotension obtained a negative consensus. The consistent and large agreement reached in this Delphi panel perfectly reflects the perception of efficacy, safety and tolerability of safinamide as evident from pivotal trials and clinical practice and shows how these findings may guide movement disorders specialists in their clinical therapeutic approach. The impact of non-motor symptoms in PD is considerable, and management remains an unmet need. In this context, the ability of safinamide to impact some non-motor symptoms may represent the most promising and distinctive feature of this compound and deserves further investigations.

A critical appraisal of MAO-B inhibitors in the treatment of Parkinson's disease

Since the 1980s, the MAO-B inhibitors have gained considerable status in the therapy of the Parkinson's disease. In addition to the symptomatic effect in mono- and combination therapies, a neuroprotective effect has repeatedly been a matter of some discussion, which has unfortunately led to a good many misunderstandings. Due to potential interactions, selegiline has declined in significance in the field. For the MAO-B inhibitor safinamide, recently introduced to the market, an additional inhibition of pathological release of glutamate has been postulated. At present, rasagiline and selegiline are being administered in early therapy as well as in combination with levodopa. Safinamide has been approved only for combination therapy with levodopa when motor fluctuations have occurred. MAO-B inhibitors are a significant therapeutic option for Parkinson's disease, an option which is too often not appreciated properly.

[Relevance of COMT inhibitors in the treatment of motor fluctuations]

Catechol O‑methyltransferase (COMT) inhibitors have been established in the treatment of Parkinson's disease for more than 20 years. They are considered the medication of choice for treating motor fluctuations. The available COMT inhibitors, entacapone, opicapone and tolcapone, differ pharmacokinetically in terms of their half-lives with implications for the dose frequency, in their indication requirements and in their spectrum of side effects, including diarrhea and yellow discoloration of urine. Many patients with motor fluctuations are currently not treated with COMT inhibitors and are, therefore, unlikely to receive individually optimized drug treatment. This manuscript summarizes the results of a working group including several Parkinson's disease experts, in which the value of COMT inhibitors was critically discussed.

The XINDI Study: A Randomized Phase III Clinical Trial Evaluating the Efficacy and Safety of Safinamide as Add-On Therapy to Levodopa in Chinese Patients with Parkinson's Disease with Motor Fluctuations

BACKGROUND

Levodopa remains the gold standard for the treatment of Parkinson's disease, but its long-term use is associated with motor complications whose management is still a significant challenge. Safinamide is a multimodal drug with proven efficacy as an adjunct to levodopa.

OBJECTIVE

The objective of this study was to investigate the efficacy and safety of safinamide as an add-on to levodopa in Chinese patients with Parkinson's disease with motor fluctuations.

METHODS

The XINDI study was a phase III, randomized, double-blind, placebo-controlled, multicenter study, with a 2-week screening period and a 16-week treatment period. The starting dose of safinamide (or placebo) was 50 mg once daily, increased to 100 mg once daily at day 15. Patients aged ≥  18 years, with idiopathic Parkinson's disease of >3 years duration, Hoehn and Yahr stage 1-4, and daily OFF time ≥  1.5 h, were eligible. Patients should follow a stable oral levodopa regimen and may receive concomitant treatment with stable doses of other anti-Parkinson drugs, except monoamine oxidase-B inhibitors. Patients with severe disabling peak-dose or biphasic dyskinesia, unpredictable or widely swinging fluctuations, other forms of parkinsonism, a history of dementia or severe cognitive dysfunction, major psychiatric illnesses, and/or clinically significant medical illnesses were excluded. The primary efficacy endpoint was the change from baseline to week 16 in the mean daily OFF time. Secondary efficacy endpoints included the Unified Parkinson's Disease Rating Scale, the Numerical Rating Scale, the Clinical Global Impression scale, and the 39-Item Parkinson's Disease Questionnaire scale. The statistical analysis of the efficacy parameters was conducted using an analysis of co-variance, except for the Clinical Global Impression scale scores that were assessed using the Wilcoxon-Mann-Whitney test. Safety was evaluated through the frequency of adverse events and serious adverse events, physical examination, vital signs, 12-lead electrocardiograms, and laboratory exams. All safety endpoints were summarized using descriptive statistics.

RESULTS

The trial enrolled 307 patients. At week 16, the difference in the change of the mean total daily OFF time between safinamide and placebo groups was 1.10 h (p < 0.0001). This change was significantly greater in the safinamide group starting from week 2, suggesting a rapid onset of drug efficacy. ON time, Unified Parkinson's Disease Rating Scale, Clinical Global Impression scale, and the 39-Item Parkinson's Disease Questionnaire showed statistically significant improvements. There were no significant between-group differences for adverse events or serious adverse events.

CONCLUSIONS

Safinamide, as add-on therapy to levodopa, significantly reduced motor fluctuations and improved motor symptoms and quality of life of Chinese patients with idiopathic Parkinson's disease. The improvements observed in the Unified Parkinson's Disease Rating Scale total and motor scores were also clinically significant. No safety concerns were identified, confirming the good tolerability profile of the drug.

CLINICAL TRIAL REGISTRATION

NCT03881371, registered on 19 March, 2019, https://clinicaltrials.gov/NCT03881371 .

Amantadine Treatment and Delayed Onset of Levodopa-Induced Dyskinesia in Patients with Early Parkinson's Disease

BACKGROUND

Levodopa-induced dyskinesia (LID) is a common motor complication in patients with Parkinson's disease (PD). Although amantadine is indicated LID treatment, it is uncertain whether early treatment with amantadine reduces the risk of LID in patients with PD.

OBJECTIVE

We aimed to evaluate the association between amantadine treatment and LID onset in patients with early-stage PD.

METHODS

This was a hospital-based retrospective cohort study that used electronic medical records from January 1, 2009 to October 31, 2016. The effect of amantadine on LID onset was compared with those of anticholinergics and monoamine oxidase type B inhibitors in patients with PD. Propensity score weighting and landmark analysis were used to reduce potential confounding. The time to LID onset was analyzed using Cox models. Sensitivity analyses were performed to determine the robustness of the results.

RESULTS

The analyses included 807, 661, and 518 patients at 6-, 12-, and 18-month landmark points, respectively. Amantadine use was associated with delayed LID onset in the 6- and 12-month landmark analyses, with adjusted hazard ratios of 0.65 (95% confidence interval [CI] 0.49-0.86) and 0.64 (95% CI 0.47-0.88), respectively. Sensitivity analysis findings were comparable to those of the main analysis.

CONCLUSIONS

Early treatment with amantadine may delay LID onset more than treatment with other symptomatic agents. Further studies are needed to elucidate the mechanism of amantadine in LID onset delay, and to validate our findings.

Spanish expert consensus on the use of safinamide in Parkinson's disease

Safinamide is a new add-on drug to levodopa for the treatment of Parkinson's disease (PD) with motor fluctuations. Due to the recent incorporation of safinamide into routine clinical practice, no post-authorisation phase IV studies on the safety of safinamide have been conducted to date. This study provides clinical management guidelines for safinamide based on the opinion of a group of experts in movement disorders. This project was developed in 2 phases: 16 local meetings in phase 1 and a national meeting in phase 2. The meetings followed a pre-established agenda. The present clinical practice guidelines are based on the main conclusions reached during the national meeting. The group concluded that safinamide is effective in reducing motor and non-motor fluctuations. PD patients with mild-to-moderate fluctuations benefit most from treatment, although the drug may also improve the clinical status of patients with advanced PD. The dose of other dopaminergic drugs may be reduced after introducing safinamide, which would contribute to reducing such adverse reactions as impulse control disorder. At doses higher than those usually prescribed, safinamide may also improve dyskinesia. The experts agreed that safinamide is well tolerated and causes few adverse reactions when compared with placebo.

Efficacy and safety evaluation of safinamide as an add-on treatment to levodopa for parkinson's disease

INTRODUCTION

While levodopa is still the most effective treatment for Parkinson's disease, concerns about long-term complications such as wearing-off and dyskinesia with levodopa usage remain.

AREAS COVERED

Safinamide is a highly selective and reversible monoamine oxidase B inhibitor introduced in the European Union, Japan, and the United States as an adjunctive agent to levodopa in PD patients with motor fluctuation. This review outlines the pharmacological properties, therapeutic effects, and tolerability of safinamide as an adjunct to levodopa in patients with advanced PD. Efficacy and safety findings from double-blind and placebo-controlled clinical trials for safinamide as an adjunct therapy to levodopa for PD are summarized.

EXPERT OPINION

Safinamide was well tolerated as a treatment for PD, and there was no significant difference in the frequency and severity of adverse events between the safinamide and placebo groups. It was also suggested that safinamide had a beneficial effect on the accompanying non-motor symptoms such as PD-related pain. Safinamide may exhibit neuroprotective effects through antioxidant and anti-glutamate effects, and research on the disease-modifying effect of PD is desired in the future.

Switch from rasagiline to safinamide in fluctuating Parkinson's disease patients: a retrospective, pilot study

Besides the inhibition of monoamine-oxidase-B, high-dose safinamide (100 mg) also blocks voltage-gated Na⁺ and Ca⁺⁺ channels and inhibits glutamate release at overactive synapses. This latter mechanism may provide further benefit to fluctuating Parkinson's disease (PD) patients compared to rasagiline. Here, we retrospectively investigated the consequences of shifting from rasagiline to high-dose safinamide in PD patients reporting symptoms of wearing-off, defined by the Wearing-Off-Questionnaire-19 (WOQ-19) score ≥3 at baseline. Seventeen PD patients were switched from rasagiline 1 mg to safinamide 100 mg because of the report of symptoms of fluctuations while under therapy with either levodopa+rasagiline or levodopa+rasagiline+dopamine agonists, or re-occurrence of fluctuations previously corrected by add-on with rasagiline. Patients were re-evaluated 4-6 months after switch. Switch to safinamide 100 mg produced benefit in 9/17 (52.9%) subjects, together with significant reduction of subjective symptoms of wearing-off. There was no report of adverse events. Findings from this retrospective, exploratory study suggest that safinamide 100 mg may produce more powerful benefit that rasagiline 1 mg as add-on to levodopa in fluctuating PD patients, possibly because of the bimodal mechanism of action of the former drug.

The Current Evidence for the Use of Safinamide for the Treatment of Parkinson's Disease

Introduction

Parkinson’s therapeutic interventions are only symptomatic. An optimal treatment should therefore address the largest number of motor and non-motor symptoms, to manage patients at best. Safinamide is one of the most recent approved drugs for fluctuating patients, in add-on to levodopa, that remains the gold standard treatment. It has a unique mechanism of action, both dopaminergic (as MAO-B inhibitor) and glutamatergic (through Na⁺ channel blockade). Results from Phase III trials, post-hoc analyses and real-life experiences suggest a beneficial effect on motor (such as tremor, bradykinesia, rigidity and gait) and non-motor (pain, mood, sleep) symptoms.

Areas Covered

Here, the authors discuss clinical efficacy and safety of safinamide, identifying the patients’ profiles that could benefit most. A search in PubMed was performed in September 2020, with no time limits. Publications’ abstracts were reviewed.

Conclusion

Safinamide is peculiar due to its double mechanism of action. Its benefits in improving motor functions and fluctuations, and some non-motor symptoms, could have a valuable impact on patients’ quality of life (QoL), together with its safety profile.

Safinamide in the treatment of Parkinson's disease

The deficiency pattern of neurotransmitters is heterogeneous in patients with Parkinson's disease. Consequence is an individual variable expression of motor and nonmotor features. They respond to agents with a broader spectrum of mode of actions, whereas dopamine substitution only targets impaired motor behavior. The pharmacological profile of safinamide includes reversible monoamine oxidase B inhibition and modulation of voltage-dependent sodium- and calcium channels with consecutive decline of glutamate release. Safinamide improves motor and nonmotor symptoms. Combination of safinamide with the catechol-O-methyltransferase inhibitor opicapone in one capsule is a promising future treatment alternative, which simplifies drug therapy in Parkinson's disease. Both agents complement each other in terms of application mode and efficacy on motor complications as adjuncts to levodopa therapy.

Safinamide as an adjunct therapy in older patients with Parkinson's disease: a retrospective study

BACKGROUND

Safinamide, as a levodopa adjunct, is effective in reducing motor fluctuations in Parkinson's disease (PD) patients; however, scarce evidence is available regarding its use in older PD patients.

AIM

To evaluate the safety and tolerability of safinamide as an adjunct therapy in patients aged ≥ 60 years with advanced PD.

METHODS

A retrospective study including 203 PD patients admitted to a geriatric day hospital, who were evaluated following an extensive clinical protocol. Safinamide use was categorized as never used, ongoing, and withdrawn. Potential correlations of Safinamide withdrawal were investigated in stepwise backward logistic regression models.

RESULTS

A total of 44 out of 203 participants were current or former users of Safinamide. Overall, 14 (32%) patients discontinued due to treatment-emergent adverse events (TEAEs). Withdrawal was not associated with older age.

CONCLUSIONS

Safinamide as an adjunct therapy in patients aged ≥ 60 years with advanced PD was found to be safe and well-tolerated in older patients. There were no specific demographic or clinical characteristics associated with suspension.

A Spanish Consensus on the Use of Safinamide for Parkinson's Disease in Clinical Practice

Safinamide is an approved drug for the treatment of fluctuations in Parkinson's disease (PD). Scarce data are available on its use in clinical practice. A group of Spanish movement disorders specialists was convened to review the use of safinamide across different clinical scenarios that may guide neurologists in clinical practice. Eight specialists with recognized expertise in PD management elaborated the statements based on available evidence in the literature and on their clinical experience. The RAND/UCLA method was carried, with final conclusions accepted after a 2-round modified Delphi process. Higher level of agreement between panellists was reached for the following statements. Safinamide significantly improves mean daily ON time without troublesome dyskinesias [corrected]. Adjunctive treatment with safinamide is associated with motor improvements in patients with mid-to-late PD. The efficacy of safinamide on motor fluctuations is maintained at long-term, with no increase over time in dyskinesias severity. The clinical benefits of safinamide on pain and depression remain unclear. Safinamide presents a similar incidence of adverse events compared with placebo. The efficacy and safety of safinamide shown in the pivotal clinical trials are reproduced in clinical practice, with improvement of parkinsonian symptoms, decrease of daily OFF time, control of dyskinesias at the long term, and good tolerability and safety.

Long-Term Efficacy of Safinamide on Symptoms Severity and Quality of Life in Fluctuating Parkinson's Disease Patients

BACKGROUND

Parkinson's disease (PD) is characterized by a wide range of motor and non-motor symptoms. Levodopa is still the most effective drug; however, its long-term use is associated with motor complications which may deteriorate patient's quality of life. Safinamide is a unique treatment modulating both dopaminergic and glutamatergic systems. Previous results from two six months, double-blind, placebo-controlled studies demonstrated that safinamide has positive effects on both motor functions and quality of life in PD patients.

OBJECTIVE

To investigate the effects of safinamide 100 mg/day over two-year treatment on PD symptoms severity and quality of life, using data from the study 018.

METHODS

Data from 352 patients were analyzed to evaluate the effects of safinamide on OFF time and ON time (with no or non-troublesome dyskinesia) in the overall population and in subgroups of patients (receiving levodopa monotherapy or with other anti-Parkinson therapies), and the effects of safinamide on motor symptoms/clinical fluctuations (by means of UPDRS III and IV) and on health-related quality of life (using UPDRS II and PDQ-39 summary index score).

RESULTS

Safinamide, administered as add-on to standard therapy in fluctuating PD patients, significantly improved motor symptoms and clinical fluctuations in the overall population and in some subgroups of patients. Additionally, safinamide improved quality of life and activities of daily living, maintaining the efficacy in the long-term.

CONCLUSIONS

The findings of these analyses suggest that safinamide may be considered an appropriate adjunct therapy in patient not sufficiently controlled. Further investigations are desirable to confirm these results in usual care setting.

Safinamide in Clinical Practice: A Spanish Multicenter Cohort Study

Background: Safinamide is an approved drug for the treatment of motor fluctuations of Parkinson's Disease (PD) patients with a potential benefit on non-motor symptoms (NMS). Methods: A retrospective multicenter cohort study was conducted, in which the clinical effect of safinamide on both motor and NMS was assessed by the Clinical Global Impression of Change scale. Furthermore, we assessed the appearance of adverse events (AEs) and its effect on dyskinesia, that were also recorded in non-fluctuating PD patients and in those previously treated with rasagiline. Results: We included 213 PD patients who received safinamide in addition to their regular levodopa therapy. Thirty-five withdrew prematurely from safinamide, mainly because of AEs. Out of 178, clinical improvement on motor and NMS was found in 76.4% and 26.2%, respectively. A total of 44 reported AEs of mild intensity. We did not find a difference concerning the clinical benefit or AEs when comparing either patients who had or had not been taking Monoamine Oxidase B Inhibitor (MAOB-I) previously or between patients with and without motor complications. Conclusions: Safinamide is an effective and safe add-on to levodopa drug for PD patients. Moreover, safinamide could elicit an additional clinical improvement in PD patients previously treated with other MAOB-I and in non- fluctuating patients with suboptimal motor control.

Rasagiline and safinamide as a dopamine-sparing therapy for Parkinson's disease

OBJECTIVES

To evaluate whether the prescription of monoamine oxidase B inhibitors (MAOB-I), rasagiline and safinamide, contributes to the reduction of levodopa and/or dopamine agonists (DA) dose in order to minimize adverse effects.

MATERIALS AND METHODS

A total of 724 patients with Parkinson's disease (PD) have been prospectively included in our database since the year 2000, representing a total of 5124 visits. For each patient and visit, antiparkinsonian treatment was recorded. In the presence of rasagiline and safinamide, we analysed the evolution of levodopa equivalent dose (LED) and LED for DA (LED-DA).

RESULTS

The data obtained from the 1664 visits between 2006 and 2010 (321 patients) and the 1709 visits between 2014 and 2018 (403 patients) were analysed in order to assess the impact of the introduction of rasagiline and safinamide, respectively. The annual mean LED remained stable without statistically significant differences. In the first period (impact of rasagiline), the annual mean LED-DA in 2010 was significantly higher than in 2006 (P = 0.001). In the second period (impact of safinamide), the annual mean LED-DA in 2018 was significantly lower than in 2014 (P = 0.002). A repeated-measure analyses of LED-DA including only patients who had taken safinamide showed a statistically significant decrease in LED-DA (P = 0.027).

CONCLUSIONS

The introduction of MAOB-I in the overall treatment of PD as part of routine clinical practice has not helped to reduce annual mean LED. However, safinamide reduces annual mean LED-DA and may be linked to a reduction in dose-dependent adverse effects in the long term.

Different Generations of Type-B Monoamine Oxidase Inhibitors in Parkinson's Disease: From Bench to Bedside

Three inhibitors of type-B monoamine oxidase (MAOB), selegiline, rasagiline, and safinamide, are used for the treatment of Parkinson's disease (PD). All three drugs improve motor signs of PD, and are effective in reducing motor fluctuations in patients undergoing long-term L-DOPA treatment. The effect of MAOB inhibitors on non-motor symptoms is not uniform and may not be class-related. Selegiline and rasagiline are irreversible inhibitors forming a covalent bond within the active site of MAOB. In contrast, safinamide is a reversible MAOB inhibitor, and also inhibits voltage- sensitive sodium channels and glutamate release. Safinamide is the prototype of a new generation of multi-active MAOB inhibitors, which includes the antiepileptic drug, zonisamide. Inhibition of MAOB-mediated dopamine metabolism largely accounts for the antiparkinsonian effect of the three drugs. Dopamine metabolism by MAOB generates reactive oxygen species, which contribute to nigro-striatal degeneration. Among all antiparkinsonian agents, MAOB inhibitors are those with the greatest neuroprotective potential because of inhibition of dopamine metabolism, induction of neurotrophic factors, and, in the case of safinamide, inhibition of glutamate release. The recent development of new experimental animal models that more closely mimic the progressive neurodegeneration associated with PD will allow to test the hypothesis that MAOB inhibitors may slow the progression of PD.

Safinamide in the management of patients with Parkinson's disease not stabilized on levodopa: a review of the current clinical evidence

Safinamide (Xadago^®) is a novel medication with both dopaminergic and non-dopaminergic effects, approved first by the European Commission and more recently by the US Food and Drug Administration (FDA) as an adjunctive treatment to carbidopa/levodopa in patients with mid- to late-stage Parkinson’s disease (PD) and motor fluctuations. It works through multiple mechanisms, namely as a reversible selective monoamine oxidase-B inhibitor and through modulation of glutamate release. Safinamide is extensively metabolized via oxidation to several inactive metabolites that are excreted primarily through the urine. Several large Phase III clinical trials of patients with advanced PD with motor fluctuations have shown that safinamide, administered orally at doses of 50–100 mg daily, increased ON time with no or non-troublesome dyskinesia, decreased daily OFF time, improved overall motor function (as measured by Unified Parkinson’s Disease Rating Scale [UPDRS] part III total score), and quality of life (as measured by Clinical Global Impression-Change and 39-item Parkinson’s Disease Questionnaire). In large clinical trials of patients with early PD on a single dopamine agonist, safinamide administered orally at a dose of 100 mg daily improved overall motor function as measured by UPDRS part III total score; however, some of the results reported were exploratory. Safinamide is generally well-tolerated and safe, with few to no treatment-related adverse events. Safinamide does not cause new or worsening dyskinesia and may be able to reduce this symptom in patients reporting it at baseline. Evidence suggests that safinamide is a good option for add-on therapy to carbidopa/levodopa in patients with advanced PD with motor complications, but there is still insufficient evidence to recommend it as monotherapy or add-on therapy in patients with early PD.

Spanish expert consensus on the use of safinamide in Parkinson's disease

Safinamide is a new add-on drug to levodopa for the treatment of Parkinson's disease (PD) with motor fluctuations. Due to the recent incorporation of safinamide into routine clinical practice, no post-authorisation phase IV studies on the safety of safinamide have been conducted to date. This study provides clinical management guidelines for safinamide based on the opinion of a group of experts in movement disorders. This project was developed in 2 phases: 16 local meetings in phase 1 and a national meeting in phase 2. The meetings followed a pre-established agenda. The present clinical practice guidelines are based on the main conclusions reached during the national meeting. The group concluded that safinamide is effective in reducing motor and non-motor fluctuations. PD patients with mild-to-moderate fluctuations benefit most from treatment, although the drug may also improve the clinical status of patients with advanced PD. The dose of other dopaminergic drugs may be reduced after introducing safinamide, which would contribute to reducing such adverse reactions as impulse control disorder. At doses higher than those usually prescribed, safinamide may also improve dyskinesia. The experts agreed that safinamide is well tolerated and causes few adverse reactions when compared with placebo.

Safinamide: a new hope for Parkinson's disease?

The loss of dopaminergic neurons (DAn) and reduced dopamine (DA) production underlies the reasoning behind the gold standard treatment for Parkinson's disease (PD) using levodopa (L-DOPA). Recently licensed by the European Medicine Agency (EMA) and US Food and Drug Administration (FDA), safinamide [a monoamine oxidase B (MOA-B) inhibitor] is an alternative to L-DOPA; as we discuss here, it enhances dopaminergic transmission with decreased secondary effects compared with L-DOPA. In addition, nondopaminergic actions (neuroprotective effects) have been reported, with safinamide inhibiting glutamate release and sodium/calcium channels, reducing the excitotoxic input to dopaminergic neuronal death. Effects of safinamide have been correlated with the amelioration of non-motor symptoms (NMS), although these remain under discussion. Overall, safinamide can be considered to have potential antidyskinetic and neuroprotective effects and future trials and/or studies should be performed to provide further evidence for its potential as an anti-PD drug.

Current and investigational non-dopaminergic agents for management of motor symptoms (including motor complications) in Parkinson's disease

INTRODUCTION

Parkinson's disease is characterized by a heterogeneous combination of motor and non motor symptoms. The nigrostriatal dopamine deficit is one of its essential pathophysiologic features. Areas covered: This invited narrative review provides an overlook over current available and future promising non dopaminergic therapeutics to modulate altered dopaminergic neurotransmission in Parkinson's disease. Current research strategies aim to proof clinical efficacy by amelioration of motor symptoms and preponderant levodopa related movement fluctuations. These so-called motor complications are characterized by involuntary movements as a result of an overstimulation of the nigrostriatal dopaminergic system or by temporary recurrence of motor symptoms, when beneficial effects of dopamine substituting drugs vane. Expert opinion: Non dopaminergic modulation of dopamine replacement is currently mostly investigated in well defined and selected patients with motor complications to get approval. However, the world of daily maintenance of patients with its individually adapted, so-called personalised, therapy will determine the real value of these therapeutics. Here the clinical experience of the treating neurologists and the courage to use unconventional drug combinations are essential preconditions for successful treatments of motor and associated non motor complications in cooperation with the patients and their care giving surroundings.

Motor Complications of Dopaminergic Medications in Parkinson's Disease

Motor complications are a consequence of the chronic treatment of Parkinson's disease (PD) and include motor fluctuations (wearing-off phenomenon) and levodopa-induced dyskinesia. Both can have a significant impact on functionality and quality of life; thus, proper recognition and management is essential. The phenomenology and temporal relationship of motor complications to the schedule of levodopa dosing can be helpful in characterizing them. There are several therapeutic approaches to motor complications, including pharmacological and surgical options. The authors summarize the different types of motor complications according to phenomenology and the currently available medical treatments, including ongoing trials for the management of this condition.

Safinamide: A Review in Parkinson's Disease

Safinamide (Xadago^®) is an orally active, selective, reversible monoamine oxidase-B inhibitor with both dopaminergic and non-dopaminergic (glutamatergic) properties. In the EU, safinamide is approved for the treatment of mid- to late-stage fluctuating Parkinson's disease (PD) as add-on therapy to a stable dose of levodopa alone or in combination with other PD medications. Safinamide 50-100 mg/day administered as a fixed or flexible dose significantly increased daily 'on' time without dyskinesia (primary endpoint) in patients with mid- to late-stage PD with motor fluctuations in 24-week, placebo-controlled clinical trials. Other outcomes, including motor function, overall clinical status and health-related quality of life, were also generally improved with safinamide. Furthermore, in an 18-month extension of one study, although dyskinesia (primary endpoint) was not significantly improved with safinamide relative to placebo, treatment benefits in other outcomes were generally sustained over 24 months of treatment. Safinamide was generally well tolerated in clinical trials; dyskinesia was the most common adverse event. Although further studies are needed, including comparative and long-term studies, current evidence indicates that safinamide extends the treatment options available for use as add-on therapy to levodopa and other PD medications in patients with mid- to late-stage PD experiencing motor fluctuations.

Nondopaminergic therapy of motor and nonmotor symptoms in Parkinson's disease: a clinician's perspective

Patients with Parkinson's disease suffer from impaired motor behavior due to the dopaminergic striatal deficit and nonmotor symptoms, which also result from nondopaminergic neuronal death. This review provides a personal opinion on treatment strategies for symptoms, resulting at least partially from nondopaminergic neurodegeneration, and on therapeutic modulation of dopaminergic neurotransmission. Patient-tailored treatment regimes on the basis of an individual risk benefit ratio as essential precondition try to balance all these symptoms. Individually varying heterogeneity of symptoms, nonlinear disease progression, treatment response, acceptance, tolerability and safety of applied therapies demand a close, consistent relationship between patient and treating physician. Daily maintenance of patients does not ask for too detailed treatment guidelines.

Population pharmacokinetic and pharmacodynamic analyses of safinamide in subjects with Parkinson's disease

Safinamide is an orally administered α‐aminoamide derivative with both dopaminergic and non‐dopaminergic properties. Nonlinear mixed effects models for population pharmacokinetic (PK) and pharmacokinetic–pharmacodynamic (PKPD) analyses were developed using records from, respectively, 623 and 668 patients belonging to two Phase 3, randomized, placebo‐controlled, double‐blind efficacy studies. The aim was to estimate safinamide population PK parameters in patients with Parkinson's disease (PD) on stable levodopa therapy, and to develop a model of safinamide effect on the PD phase of normal functioning (ON‐time). The final models were internally evaluated using visual predictive checks (VPCs), prediction corrected‐VPC, and nonparametric bootstrap analysis. Safinamide profiles were adequately described by a linear one‐compartmental model with first‐order absorption and elimination. CL/F, Vd/F, and KA (95% confidence interval [CI]) were 4.96 (4.73–5.21) L/h, 166 (158–174) L, and 0.582 (0.335–0.829) h⁻¹, respectively. CL/F and Vd/F increased with body weight, while age, gender, renal function, and exposure to levodopa did not influence safinamide PK. The observed ON‐time values were adequately described by a linear model, with time in the study period as dependent variable, and rate of ON‐time change and baseline plus offset effect as slope and intercept parameters. Safinamide treatment resulted in an increase in ON‐time of 0.73 h (week 4), with further ON‐time increase with the same slope as placebo. The increase was not influenced by age, levodopa, or safinamide exposure. The population models adequately describe the population PK of safinamide and safinamide effect on ON‐time. No dose adjustments in elderly and mild to moderate renally impaired patients are requested.

Emerging approaches in Parkinson's disease - adjunctive role of safinamide

Ongoing neuronal death in Parkinson’s disease (PD) causes an altered neurotransmission of various biogenic amines, particularly dopamine. As these changes do not follow a distinct pattern, they vary individually, and are differently pronounced. As a result, a heterogeneous onset of motor and nonmotor features occurs in each patient with PD during the whole course of the disease. PD actually describes a set of distinct diseases that manifest themselves in clinical syndromes with certain similarities but also great differences. This clinical picture responds to drugs with a broad spectrum of modes of actions better than to compounds with an exclusive focus on specific receptor subtypes. Therefore, safinamide is an ideal candidate for treatment of patients with PD, since its pharmacological profile includes reversible monoamine oxidase-B inhibition, blockade of voltage-dependent sodium channels, modulation of calcium channels, and inhibition of glutamate release. Safinamide is applied only once daily. Its oral dose ranges from 50 to 100 mg. Safinamide was well tolerated and safe in the clinical development program that demonstrated the amelioration of motor symptoms and OFF phenomena by safinamide when combined with dopamine agonists or levodopa. In the real world of maintenance of patients with PD, effects of safinamide application resemble therapy with classical monoamine oxidase inhibitors or amantadine in combination with other dopamine-substituting drugs. Safinamide is becoming increasingly available in the EU despite complex approval and pricing scenarios.

Synthesis and Evaluation of Novel α-Aminoamides Containing an Indole Moiety for the Treatment of Neuropathic Pain

The α-aminoamide family of sodium ion channel blockers have exhibited analgesic effects on neuropathic pain. Here, a series of novel α-aminoamides containing an indole ring were designed and synthesized. These compounds were evaluated in mice using a formalin test and they exhibited significant anti-allodynia activities. However, the analgesic mechanism of these compounds remains unclear; a subset of the synthesized compounds can only moderately inhibit the sodium ion channel, Nav1.7, in a whole-cell patch clamp assay. Overall, these results suggest that introduction of an indole moiety to α-aminoamide derivatives can significantly improve their bioactivity and further study is warranted.

Nondopaminergic treatments for Parkinson's disease: current and future prospects

Parkinson's disease is primarily caused by dysfunction of dopaminergic neurons, however, nondopaminergic (ND) systems are also involved. ND targets are potentially useful to reduce doses of levodopa or to treat nonlevodopa-responsive symptoms. Recent studies have investigated the role of ND drugs for motor and nonmotor symptoms. Adenosine A2A receptor antagonists, mixed inhibitors of sodium/calcium channels and monoamine oxidase-B have recently been found to improve motor fluctuations. N-methyl-d-aspartate receptor antagonists and serotonin 5HT1B receptor agonists demonstrated benefit in levodopa-induced dyskinesia. Conversely, studies using antiepileptic drugs and adrenoreceptor antagonist had conflicting results. Moreover, metabotropic glutamate receptor antagonists also failed to improve symptoms. The current review summarizes the most recent findings on ND drugs over the last 2 years.