Investigation of the absolute bioavailability, mass balance, metabolism, and excretion of the cholesterol 24-hydroxylase inhibitor soticlestat in healthy volunteers.

AIMS: Our aim was to determine the absolute bioavailability, mass balance, metabolism and excretion of soticlestat (TAK-935). METHODS: An open-label, two-period, single-site, phase 1 study was conducted in six healthy men. In Period 1, a single 300 mg dose of soticlestat was administered orally, followed by a 15-min intravenous infusion of [14 C]soticlestat 50 µg (~1 µCi) 10 min later. In Period 2, a single 300 mg dose (~100 µCi) of [14 C]soticlestat in solution was administered orally. Samples were collected, analysed for radioactivity or unchanged soticlestat, and profiled for metabolites. RESULTS: In Period 1, soticlestat had an absolute bioavailability of 12.6% (90% confidence interval, 7.81-20.23%). In Period 2, there was near-complete recovery of total radioactivity (TRA) following a 300 mg dose of [14 C]soticlestat: urine, 94.8% (standard deviation [SD], 1.35%); faeces, 2.7% (SD, 1.67%). Of TRA, 0.1% (SD, 0.09%) and 0.6% (SD, 0.21%) were recovered as soticlestat and metabolite M-I in urine, respectively. In plasma, soticlestat and M-I reached geometric mean maximum observed concentrations of 1352 ng/mL (geometric percent coefficient of variation [gCV%], 61.3) and 253.2 ng/mL (gCV%, 44.1) after 25 min and declined with mean terminal half-lives (SD) of 5.7 (2.90) and 2.0 (0.15) h, respectively. Soticlestat represented 4.9% of TRA in plasma. Soticlestat was rapidly eliminated primarily via O-glucuronidation to metabolite M3, which was the dominant species in plasma (92.6%) and urine (86%). CONCLUSIONS: This study indicates that soticlestat and its metabolites are rapidly cleared and eliminated, lowering the risk of dose accumulation from repeated dosing and supporting further investigation of soticlestat.

Efficacy, safety, and tolerability of soticlestat as adjunctive therapy for the treatment of seizures in patients with Dup15q syndrome or CDKL5 deficiency disorder in an open-label signal-finding phase II study (ARCADE).

OBJECTIVE: Chromosome 15q duplication (Dup15q) syndrome and cyclin­dependent kinase-like 5 deficiency disorder (CDD) are rare neurodevelopmental disorders associated with epileptic encephalopathies, with a lack of specifically approved treatment options. ARCADE assessed the efficacy and safety of adjunctive soticlestat (TAK-935) for the treatment of seizures in patients with Dup15q syndrome or CDD (NCT03694275). METHODS: ARCADE was a phase II, open-label, pilot study of soticlestat (≤300 mg/day twice daily, weight-adjusted) in pediatric and adult patients 2-55 years of age with Dup15q syndrome or CDD who experienced ≥3 motor seizures per month in the 3 months before screening and at baseline. The 20-week treatment period consisted of a dose-optimization period and a 12-week maintenance period. Efficacy endpoints included the change from baseline in motor seizure frequency during the maintenance period and the proportion of treatment responders. Safety endpoints included the incidence of treatment-emergent adverse effects (TEAEs). RESULTS: The modified-intent-to-treat population included 20 participants who received ≥1 dose of soticlestat and had ≥1 efficacy assessment (Dup15q syndrome, n = 8; CDD, n = 12). Soticlestat administration during the maintenance period was associated with a median change from baseline in motor seizure frequency of +11.7% in the Dup15q syndrome group and -23.6% in the CDD group. Reductions in all seizure frequency of -23.4% and -30.5% were also observed during the maintenance period in the Dup15q syndrome group and the CDD group, respectively. Most TEAEs were of mild or moderate severity. Serious TEAEs were reported by three patients (15.0%); none were considered drug related. The most common TEAEs were constipation, rash, and seizure. No deaths were reported. CONCLUSIONS: Adjunctive soticlestat treatment was associated with a decrease in motor seizure frequency from baseline in patients with CDD and a decrease in all seizure frequency in both patient groups. Soticlestat treatment was associated with an increase in motor seizure frequency in patients with Dup15q syndrome.

Randomized controlled study to evaluate the efficacy and safety of soticlestat as adjunctive therapy in adults with complex regional pain syndrome.

OBJECTIVE: The objective was to investigate the efficacy and safety of soticlestat as adjunctive therapy in participants with complex regional pain syndrome (CRPS). DESIGN: A proof-of-concept phase 2a study, comprising a 15-week randomized, double-blind, placebo-controlled, parallel-group study (part A), and an optional 14-week open-label extension (part B). METHODS: Twenty-four participants (median age 44.5 years [range, 18-62 years]; 70.8% female) with chronic CRPS were randomized (2:1) to receive oral soticlestat or placebo. Soticlestat dosing started at 100 mg twice daily and was titrated up to 300 mg twice daily. In part B, soticlestat dosing started at 200 mg twice daily and was titrated up or down at the investigator's discretion. Pain intensity scores using the 11-point Numeric Pain Scale (NPS) were collected daily. The Patient-Reported Outcomes Measurement Information System (PROMIS)-29, Patients' Global Impression of Change (PGI-C), and CRPS Severity Score (CSS) were completed at screening and weeks 15 and 29. RESULTS: From baseline to week 15, soticlestat treatment was associated with a mean change in 24-hour pain intensity NPS score (95% confidence interval) of -0.75 (-1.55, 0.05) vs -0.41 (-1.41, 0.59) in the placebo group, resulting in a non-significant placebo-adjusted difference of -0.34 (-1.55, 0.88; P = .570). Statistically non-significant numerical changes were observed for the PROMIS-29, PGI-C, and CSS at weeks 15 and 29. CONCLUSIONS: Adjunctive soticlestat treatment did not significantly reduce pain intensity in participants with chronic CRPS.

A phase 2, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of soticlestat as adjunctive therapy in pediatric patients with Dravet syndrome or Lennox-Gastaut syndrome (ELEKTRA).

OBJECTIVE: Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) are rare treatment-resistant childhood epilepsies classed as developmental and epileptic encephalopathies. ELEKTRA investigated the efficacy and safety of soticlestat (TAK-935) as adjunctive therapy in children with DS or LGS (NCT03650452). METHODS: ELEKTRA was a phase 2, randomized, double-blind, placebo-controlled study of soticlestat (≤300 mg twice daily, weight-adjusted) in children (aged 2-17 years) with DS, demonstrating three or more convulsive seizures/month, or with LGS, demonstrating four or more drop seizures/month at baseline. The 20-week treatment period comprised an 8-week dose-optimization period and a 12-week maintenance period. Efficacy endpoints included change from baseline in seizure frequency versus placebo. Safety assessments included incidence of treatment-emergent adverse events (TEAEs). RESULTS: ELEKTRA enrolled 141 participants; 126 (89%) completed the study. The modified intent-to-treat population included 139 participants who received one or more doses of study drug and had one or more efficacy assessments (DS, n = 51; LGS, n = 88). ELEKTRA achieved its primary endpoint: the combined soticlestat-treated population demonstrated a placebo-adjusted median reduction in seizure frequency of 30.21% during the maintenance period (p = .0008, n = 139). During this period, placebo-adjusted median reductions in convulsive and drop seizure frequencies of 50.00% (p = .0002; patients with DS) and 17.08% (p = .1160; patients with LGS), respectively, were observed. TEAE incidences were similar between the soticlestat (80.3%) and placebo (74.3%) groups and were mostly mild or moderate in severity. Serious TEAEs were reported by 15.5% and 18.6% of participants receiving soticlestat and placebo, respectively. TEAEs reported in soticlestat-treated patients with ≥5% difference from placebo were lethargy and constipation. No deaths were reported. SIGNIFICANCE: Soticlestat treatment resulted in statistically significant, clinically meaningful reductions from baseline in median seizure frequency (combined patient population) and in convulsive seizure frequency (DS cohort). Drop seizure frequency showed a nonstatistically significant numerical reduction in children with LGS. Soticlestat had a safety profile consistent with previous studies.

An observational study of rotigotine transdermal patch and other currently prescribed therapies in patients with Parkinson's disease.

Real-world data from large cohorts of patients with Parkinson's disease on the long-term effectiveness of different dopamine-substituting drug therapies are rare. The objective of this study was to obtain information on real-world management of PD with dopamine-substituting drugs. SP0854 (NCT00599339) was a prospective, multicenter, non-interventional, multiple-cohort, post-authorization safety study of rotigotine versus other dopaminergic therapies. The study was also part of a European Medicines Agency risk-management plan for the non-ergoline dopamine agonist rotigotine, focussing on cardiovalvular fibrosis. Eligible patients requiring monotherapy with a dopamine agonist, or levodopa in combination with a dopamine agonist were followed for ≤ 33 months; 1531 of 2195 patients completed the study. Mean motor scores improved for all dopamine-substituting treatments. Patients with more severe motor-symptoms/increased disability were more likely to receive levodopa alone or in combination with a DA at study onset. More patients who started on combination therapy with levodopa remained on this treatment versus those starting on dopaminergic monotherapy. This real-world study showed that the dopamine-substituting therapies were efficacious, with a safety profile consistent with that expected of dopaminergic treatments. Cardiovalvular pathology was rare and not found to be causally-related to rotigotine.

ICARUS study: prevalence and clinical features of impulse control disorders in Parkinson's disease.

BACKGROUND: Impulse control disorders/other compulsive behaviours ('ICD behaviours') occur in Parkinson's disease (PD), but prospective studies are scarce, and prevalence and clinical characteristics of patients are insufficiently defined. OBJECTIVES: To assess the presence of ICD behaviours over a 2-year period, and evaluate patients' clinical characteristics. METHODS: A prospective, non-interventional, multicentre study (ICARUS (Impulse Control disorders And the association of neuRopsychiatric symptoms, cognition and qUality of life in ParkinSon disease); SP0990) in treated Italian PD outpatients. Study visits: baseline, year 1, year 2. Surrogate primary variable: presence of ICD behaviours and five ICD subtypes assessed by modified Minnesota Impulsive Disorder Interview (mMIDI). RESULTS: 1069/1095 (97.6%) patients comprised the Full Analysis Set. Point prevalence of ICD behaviours (mMIDI; primary analysis) was stable across visits: 28.6% (306/1069) at baseline, 29.3% (292/995) at year 1, 26.5% (245/925) at year 2. The most prevalent subtype was compulsive eating, followed by punding, compulsive sexual behaviour, gambling and buying disorder. Patients who were ICD positive at baseline were more likely to be male, younger, younger at PD onset, have longer disease duration, more severe non-motor symptoms (including mood and sexual function), depressive symptoms, sleep impairment and poorer PD-related quality of life. However, they did not differ from the ICD-negative patients in their severity of PD functional disability, motor performance and cognitive function. CONCLUSIONS: Prevalence of ICD behaviours was relatively stable across the 2-year observational period. ICD-positive patients had more severe depression, poorer sleep quality and reduced quality of life.

Evaluation of rotigotine transdermal patch for the treatment of apathy and motor symptoms in Parkinson's disease.

BACKGROUND: This multicenter, double-blind, placebo-controlled study assessed the efficacy of rotigotine transdermal patch on apathy and motor symptoms in patients with Parkinson's disease (PD). METHODS: Patients with PD-associated apathy (Unified Parkinson's Disease Rating Scale [UPDRS] I item 4 [motivation] ≥2 and patient-rated Apathy Scale [AS] ≥14) were randomized 1:1:1 to "low-dose" rotigotine (≤6 mg/24 h for early PD [those not receiving levodopa] or ≤8 mg/24 h for advanced PD [those receiving levodopa]), "high-dose" rotigotine (≤8 mg/24 h for early PD or ≤16 mg/24 h for advanced PD), or placebo, and maintained at optimal/maximal dose for 12 weeks. Coprimary efficacy variables were: change from baseline to End of Maintenance in patient-rated AS and UPDRS II + III total score. Recruitment was stopped after an interim futility analysis; therefore, all p values are exploratory. RESULTS: Of 122 patients randomized, 81.1 % completed the study (placebo, n = 32/40 [80.0 %]; low-dose rotigotine, n = 30/41 [73.2 %]; high-dose rotigotine, n = 37/41 [90.2 %]). No treatment difference was observed in the change in patient-rated AS (least squares mean [95 % confidence interval (CI)] difference: low-dose, 0.04 [-2.42, 2.50], p =0.977; high-dose, -0.22 [-2.61, 2.18], p = 0.859). Rotigotine improved UPDRS II + III total scores versus placebo (least squares mean [95 % CI] treatment difference: low-dose, -7.29 [-12.30, -2.28], p = 0.005; high-dose, -6.06 [-10.90, -1.21], p = 0.015), and the "mood/apathy" domain of the Non-Motor Symptom Scale as rated by the investigator (secondary outcome). The most frequent adverse events in rotigotine-treated patients were application site reactions, somnolence, and nausea. CONCLUSIONS: Rotigotine did not improve PD-associated apathy as rated by the patient but provided clinically relevant improvement in motor control and activities of daily living. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01782222 . Trial registration date: January 30, 2013.

Population pharmacokinetics, enzyme occupancy, and pharmacodynamic modeling of soticlestat in patients with developmental and epileptic encephalopathies.

Soticlestat (TAK-935) is a first-in-class, selective inhibitor of cholesterol 24-hydroxylase (CH24H) under phase III development for the treatment of the developmental and epileptic encephalopathies (DEEs), Dravet syndrome (DS), and Lennox-Gastaut syndrome (LGS). A previous model characterized the pharmacokinetics (PKs), CH24H enzyme occupancy (EO), and pharmacodynamics (PDs) of soticlestat in healthy volunteers. The present study extended this original model for patients with DEEs and investigated sources of variability. Model-based simulations were carried out to optimize dosing strategies for use in clinical trials. Data from eight phase I and II trials of healthy volunteers or patients with DEEs receiving oral soticlestat 15-1350 mg were included, encompassing 218 individuals for population PK (PopPK) analyses and 306 individuals for PK/PD analyses. Dosing strategies were identified through model-based simulations. The final mixed-effect PopPK/EO/PD model consisted of a two-compartment PK model and an effect-site compartment in the PK/EO model; soticlestat concentrations at the effect site were linked to 24S-hydroxycholesterol plasma concentrations using a semimechanistic inhibitory indirect response model. Covariates were included to account for sources of variability. Pediatric dosing strategies were developed for four body weight bands (10 to <15, 15 to <30, 30 to <45, and 45-100 kg) to account for covariate effects by body weight. The final PopPK and PK/EO/PD models accurately described PK, EO, and PD profiles of soticlestat in healthy volunteers and patients with DEEs. Covariate analyses and model-based simulations facilitated optimization of phase III trial dosing strategies for patients with DS or LGS.

INTERACT: a randomized phase 2 study of the DAAO inhibitor luvadaxistat in adults with schizophrenia.

Deficits in N-methyl-d-aspartate receptor (NMDAR) signaling are implicated in the pathogenesis of schizophrenia. Luvadaxistat (TAK-831/NBI-1065844) is an investigational d-amino acid oxidase (DAAO) inhibitor that increases d-serine levels at NMDAR coagonist sites. INTERACT is a phase 2 randomized, placebo-controlled study that evaluated the efficacy and safety of three doses of luvadaxistat, covering a range of DAAO occupancy and d-serine levels, in patients with schizophrenia with persistent negative symptoms. The study included a 14-day, single-blinded placebo run-in period and a 12-week, double-blinded treatment period. The primary efficacy endpoint was the 12-week change from baseline in Positive and Negative Syndrome Scale-Negative Symptom Factor Score (PANSS NSFS). Secondary efficacy endpoints included the 12-week changes from baseline in Brief Assessment of Cognition in Schizophrenia (BACS) score and Schizophrenia Cognition Rating Scale (SCoRS) score. Safety endpoints included adverse event assessments. The full analysis set included all randomized patients (N = 256 [placebo, n = 87; luvadaxistat 50 mg, n = 58; 125 mg, n = 56; 500 mg, n = 55]); 228 patients completed the study. No significant improvements in PANSS NSFS were observed at any dose versus placebo at week 12. Improvements were observed with luvadaxistat 50 mg versus placebo in cognitive endpoints: BACS composite score (nominal one-sided p = 0.031) and SCoRS interviewer total score (nominal one-sided p = 0.011). Luvadaxistat did not significantly improve negative symptoms of schizophrenia. However, luvadaxistat 50 mg met the prespecified secondary endpoints for cognitive performance (BACS) and function (SCoRS), warranting further investigation in patients with cognitive impairment associated with schizophrenia. Luvadaxistat was well-tolerated in INTERACT, with no new safety signals observed. ClinicalTrials.gov: NCT03382639.

Population pharmacokinetics, enzyme occupancy, and 24S-hydroxycholesterol modeling of soticlestat, a novel cholesterol 24-hydroxylase inhibitor, in healthy adults.

Soticlestat is a first-in-class, selective inhibitor of cholesterol 24-hydroxylase (CH24H), which catabolizes cholesterol to 24S-hydroxycholesterol (24HC) in the brain, in phase III development for Dravet syndrome and Lennox-Gastaut syndrome treatment. This study aimed to develop a model of soticlestat pharmacokinetics (PKs) and pharmacodynamics (PDs) using 24HC plasma concentrations and CH24H enzyme occupancy (EO) time profiles. Subsequently, model-based simulations were conducted to identify dosing strategies for phase II trials in children and adults with developmental and epileptic encephalopathies (DEEs). Four phase I trials of healthy adults involving oral administration of soticlestat 15-1350 mg were used to develop the mixed-effect population PK/EO/PD model. The population PK analysis utilized 1727 observations (104 individuals), PK/EO analysis utilized 20 observations (11 individuals), and PK/PD analysis utilized 2270 observations (99 individuals). Optimal dosing strategies were identified from model-based PK, EO, and PD simulations. The PK/EO/PD model described the observed data well and comprised a two-compartment model with dose as a covariate on peripheral volume, linear elimination, and intercompartmental clearance. Transit and effect-site compartments were included to accommodate different dosage forms and the delay between plasma drug concentrations and EO. Model-based simulations indicated that soticlestat 100-300 mg twice daily may be an optimal adult dosing regimen with weight-adjusted pediatric dosing strategies identified for evaluation in phase II trials. The population PK/EO/PD model provided understanding of the soticlestat PK/PD relationship with partial delineation of sources of variability, and identified dosing strategies for phase II trials of children and adults with DEEs.

The D-amino acid oxidase inhibitor luvadaxistat improves mismatch negativity in patients with schizophrenia in a randomized trial.

Several attempts have been made to enhance N-methyl-D-aspartate (NMDA) receptor function in schizophrenia, but they have yielded mixed results. Luvadaxistat, a D-amino acid oxidase (DAAO) inhibitor that increases the glutamate co-agonist D-serine levels, is being developed for the treatment of cognitive impairment associated with schizophrenia. We conducted a biomarker study in patients, assessing several endpoints related to physiological outcomes of NMDA receptor modulation to determine whether luvadaxistat affects neural circuitry biomarkers relevant to NMDA receptor function and schizophrenia. This was a randomized, placebo-controlled, double-blind, two-period crossover phase 2a study assessing luvadaxistat 50 mg and 500 mg for 8 days in 31 patients with schizophrenia. There were no treatment effects of luvadaxistat at either dose in eyeblink conditioning, a cerebellar-dependent learning measure, compared with placebo. We observed a nominally significant improvement in mismatch negativity (MMN) and a statistical trend to improvement for auditory steady-state response at 40 Hz, in both cases with 50 mg, but not with 500 mg, compared with placebo. Although the data should be interpreted cautiously owing to the small sample size, they suggest that luvadaxistat can improve an illness-related circuitry biomarker at doses associated with partial DAAO inhibition. These results are consistent with 50 mg, but not higher doses, showing a signal of efficacy in cognitive endpoints in a larger phase 2, 12-week study conducted in parallel. Thus, MMN responses after a short treatment period may predict cognitive function improvement. MMN and ASSR should be considered as biomarkers in early trials addressing NMDA receptor hypofunction.

Central nervous system effects of TAK-653, an investigational alpha-amino-3-hydroxy-5-methyl-4-isoxazole receptor (AMPAR) positive allosteric modulator in healthy volunteers.

TAK-653 is a novel AMPA receptor positive allosteric modulator in clinical development for the treatment of major depressive disorder (MDD). This study aimed to measure the functional pharmacodynamic central nervous system (CNS) effects of TAK-653. A randomised, double-blind, placebo-controlled, three-way crossover (placebo, TAK-653 0.5 mg and 6 mg) study with 24 healthy volunteers was performed. NeuroCart tests consisting of body sway (BS), saccadic peak velocity (SPV), smooth pursuit eye movements (SP), adaptive tracking (AT), Bowdle and Bond and Lader Visual Analogue Scales (B-VAS and BL-VAS) and Stroop test were performed pre-dose and 3.5 and 4 h post-dose. Data were analysed using a mixed model analysis of covariance with baseline as covariate. It was found that TAK-653 did not affect BS and subjective drug effects as measured by B-VAS and BL-VAS at either dose level. TAK-653 0.5 mg increased SPV (degrees/second) (19.49 [5.98, 32.99], P = 0.02) and affected Stroop difference in reaction time between correct congruent and correct incongruent answers and number of correct responses in incongruent trials (22.0 [4.0, 40.0], P = 0.05 and -0.3 [-0.5, -0.1], P = 0.02, respectively). TAK-653 6 mg improved AT (%) (1.68 [0.51, 2.84], P = 0.02) and increased SPV (degrees/s) (15.40 [1.91, 28.90], P = 0.06) and SP (%) (2.32 [0.37, 4.27], P = 0.05). Based on these findings it can be concluded that TAK-653 demonstrated a psychostimulant-like pharmacodynamic profile on the NeuroCart consistent with previously reported increase of cortical excitability following Transcranial Magnetic Stimulation (TMS) of the human motor cortex.

A phase 1b/2a study of soticlestat as adjunctive therapy in participants with developmental and/or epileptic encephalopathies.

OBJECTIVE: To evaluate the safety, tolerability, and pharmacokinetics of soticlestat, a first-in-class cholesterol 24-hydroxylase inhibitor, in adults with developmental and/or epileptic encephalopathies (DEE). METHODS: The study comprised a 30-day, randomized, double-blind, placebo-controlled phase (Part A), followed by a 55-day open-label phase (Part B) (ClinicalTrials.gov ID: NCT03166215) . In Part A, patients with DEE and at least one bilateral motor seizure during the 4-week prospective baseline period were randomized 4:1 to receive soticlestat or placebo, in addition to their usual antiseizure medication. In Part B, all patients received open-label soticlestat. Soticlestat doses were titrated according to tolerability to a maximum of 300 mg twice daily (BID). Safety evaluations included the incidence of treatment-emergent adverse events (TEAEs). Plasma soticlestat concentrations were measured at various times for determination of multiple-dose pharmacokinetics and 24S-hydroxycholesterol (24HC). Efficacy was assessed by evaluation of changes in seizure frequency from baseline. RESULTS: Eighteen patients (median age, 28.5 years) were enrolled and randomized, and 14 (78 %) completed the study. In Part A, TEAEs occurred in 71.4 % of soticlestat-treated patients and 100 % of placebo-treated patients. In Part B, the overall incidence of TEAEs was 68.8 %. In Part A, TEAEs that occurred in more than one patient in the soticlestat group were dysarthria (n = 3, 21.4 %), lethargy (n = 2, 14.3 %), upper respiratory tract infection (n = 2, 14.3 %), fatigue (n = 2, 14.3 %), and headache (n = 2, 14.3 %). Four patients discontinued treatment because of TEAEs, of whom two reported drug-related seizure clusters as serious TEAEs. There were no deaths. Pharmacokinetic analysis showed dose-dependent increases in systemic exposure and peak plasma soticlestat concentrations. At the end of Part B, the overall mean percent change from baseline in plasma 24HC was -80.97 %. Changes from baseline in median seizure frequency were +16.71 % and +22.16 % in the soticlestat and placebo groups, respectively, in Part A, and -36.38 % in all participants in Part B. CONCLUSION: Soticlestat was well tolerated at doses of up to 300 mg BID and was associated with a reduction in median seizure frequency over the study duration. Further studies are warranted to assess the possible efficacy of soticlestat as adjunctive therapy in patients with DEEs such as Dravet syndrome and Lennox-Gastaut syndrome.

Transcranial magnetic stimulation as a translational biomarker for AMPA receptor modulation.

TAK-653 is a novel α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-positive allosteric modulator being developed as a potential therapeutic for major depressive disorder (MDD). Currently, there are no translational biomarkers that evaluate physiological responses to the activation of glutamatergic brain circuits available. Here, we tested whether noninvasive neurostimulation, specifically single-pulse or paired-pulse motor cortex transcranial magnetic stimulation (spTMS and ppTMS, respectively), coupled with measures of evoked motor response captures the pharmacodynamic effects of TAK-653 in rats and healthy humans. In the rat study, five escalating TAK-653 doses (0.1-50 mg/kg) or vehicle were administered to 31 adult male rats, while measures of cortical excitability were obtained by spTMS coupled with mechanomyography. Twenty additional rats were used to measure brain and plasma TAK-653 concentrations. The human study was conducted in 24 healthy volunteers (23 males, 1 female) to assess the impact on cortical excitability of 0.5 and 6 mg TAK-653 compared with placebo, measured by spTMS and ppTMS coupled with electromyography in a double-blind crossover design. Plasma TAK-653 levels were also measured. TAK-653 increased both the mechanomyographic response to spTMS in rats and the amplitude of motor-evoked potentials in humans at doses yielding similar plasma concentrations. TAK-653 did not affect resting motor threshold or paired-pulse responses in humans. This is the first report of a translational functional biomarker for AMPA receptor potentiation and indicates that TMS may be a useful translational platform to assess the pharmacodynamic profile of glutamate receptor modulators.

The characteristics and treatment patterns of patients with Parkinson's disease in the United States and United Kingdom: A retrospective cohort study.

OBJECTIVES: The objective of the study was to describe treatment patterns in patients newly diagnosed with Parkinson's disease (PD) in the United States (US) and the United Kingdom (UK). METHODS: This retrospective cohort study used the US IBM MarketScan database (2012-2017) and the UK Clinical Practice Research Datalink (CPRD) (2004-2015) database to describe treatment patterns in incident PD cases. Patients fulfilling the case definition of PD, ≥30 years, with a 2-year baseline period prior to the index date (date of PD diagnosis), and ≥90 days of follow-up were included in the study. Treatment was classified as monotherapy (one PD medication for ≥60 continuous days), polytherapy (at least two PD medications concurrently for ≥60 days), or untreated (no PD medication prescription). Treatment patterns described included type of medication, duration and outcome of treatment. RESULTS: There were 11,280 patients in IBM MarketScan and 7775 patients in CPRD who fulfilled the study criteria. The proportion of treated patients was 62.4% (US) and 78.6% (UK). The majority of patients were prescribed monotherapy as first-line treatment (US: 85.2%, UK: 68.5%). Levodopa was the most frequently prescribed first-line medication (US: 70.1%, UK: 29.0%). There were 57.9% in the US and 23.8% in the UK who remained on the first monotherapy treatment till the end of the study. CONCLUSION: The study has highlighted the current treatment practices in the US and UK, and underscored differences in the two regions impacted by treatment policies and guidelines.

Risk factors for impulse control disorders and related behaviors in Parkinson's disease: secondary analyses of the ICARUS study.

Objective: Impulse control disorders and related behaviors (ICDs) are common in patients with Parkinson's disease (PD), yet incidence and predictive factors are not fully understood. We examined the epidemiology of ICDs in PD through secondary and post-hoc analyses of data from the ICARUS (SP0990) study, which enrolled >1000 patients. Methods: Using a modified-Minnesota Impulsive Disorders Interview (mMIDI), ICD incidence was calculated for patients who were ICD-negative at baseline but ICD-positive at year 1, and year 1 and/or 2 (cumulative 2-year ICD incidence). The proportion of "new cases" (ICD-negative at baseline, but ICD-positive at year 1 or 2), and "remitters" (ICD-positive at baseline but ICD-negative at year 1 or 2) was also calculated for the whole ICARUS population. Results: Among 709 patients ICD-negative at baseline, 97 screened ICD-positive (13.7%) at year 1. Among 712 patients who were ICD-negative at baseline, 147 were ICD-positive at ≥1 post-baseline visit (20.6%). Among patients who were ICD-negative at baseline who subsequently experienced an ICD, a higher proportion were male or smokers, younger at baseline, younger at disease/symptom onset, and had longer disease duration. Among the whole population, a similar proportion were "new cases" at years 1 (9.7%) and 2 (8.6%) versus the previous visit. The proportion of "remitters" was slightly higher at year 2 (11.0%) than 1 (9.1%) versus previous visit. Conclusions: The proportion of ICD-remitters approximately matched/exceeded new cases, suggesting patients with ICD are in a state of flux. Current data allow for a conservative estimate of 2-year ICD incidence in ICARUS of ∼21% of patients, not accounting for transient new ICD cases between visits.

Pharmacokinetics, Tolerability, and Bioequivalence of Two Formulations of Rotigotine in Healthy Chinese Subjects.

PURPOSE: The pharmacokinetic (PK) profile of the rotigotine transdermal patch is well characterized in Caucasian patients with Parkinson's disease (PD) but not in Chinese subjects. This article reports the PK variables, safety, and tolerability of the rotigotine transdermal patch (2 mg/24 hours and 4 mg/24 hours cold-chain PR2.1.1 formulation) in healthy Chinese subjects (SP0913; NCT01675024). A second study (PD0011; NCT02070796) evaluated the relative bioavailability of cold-chain (PR2.1.1) and room temperature-stable (PR2.2.1) formulations of rotigotine in healthy Chinese men. METHODS: In treatment period 1 of SP0913, subjects received a single application of rotigotine 2 mg/24 hours on day 1 followed by a washout period (days 2-6); treatment period 2 (days 6-14) involved multiple doses of rotigotine 2 mg/24 hours (days 7-9) followed by multiple doses of rotigotine 4 mg/24 hours (days 10-12), with patches applied for 24 hours each. In PD0011, subjects received a single dose (2 mg/24 hours) of each rotigotine formulation (PR2.2.1 and PR2.1.1) for 24 hours each in a crossover design. Blood samples were collected at scheduled time points to determine rotigotine plasma concentrations. Safety and tolerability were evaluated by adverse events monitoring. RESULTS: Twenty-four healthy Chinese subjects (12 males, 12 females) were enrolled and completed SP0913. Geometric mean plasma concentrations of unconjugated and total rotigotine increased to a plateau beginning at ∼8 hours (multiple dose) to 16 hours (single dose) postdose; no characteristic Tmax was observed for unconjugated and total rotigotine. The respective geometric mean Cmax, Cmax,ss, AUC from zero up to the last analytically quantifiable concentration, and AUC0-24,ss values for unconjugated and total rotigotine were similar when rotigotine 2 mg/24 hours was applied as a single dose or multiple-dose regimen. During the multiple-dose period, geometric mean Cmax,ss and AUC0-24,ss of both unconjugated and total rotigotine were ∼2-fold higher for rotigotine 4 mg/24 hours than for rotigotine 2 mg/24 hours. Forty-seven of 50 male Chinese subjects completed PD0011. Primary PK parameters for the room temperature-stable formulation of rotigotine were highly comparable to the cold-chain formulation. Common adverse events included application site pruritus, nausea, dizziness, and constipation (SP0913 only), with no clinically significant changes in other safety measures. IMPLICATIONS: PK profiles and derived PK parameters of unconjugated and total rotigotine in healthy Chinese subjects were consistent with findings from other ethnic groups receiving single and multiple doses of the rotigotine transdermal patch. Single and repeated daily doses of the rotigotine transdermal patch were well tolerated. Room temperature-stable and cold-chain formulations were bioequivalent. ClinicalTrials.gov identifiers: NCT01675024 and NCT02070796.

A noninterventional study evaluating the effectiveness of rotigotine and levodopa combination therapy in younger versus older patients with Parkinson's disease.

BACKGROUND: PD0013 was a 6-month noninterventional study in clinical practice comparing effectiveness/tolerability of rotigotine+levodopa in younger (<70 years) vs. older (≥70 years) Parkinson's disease (PD) patients. METHODS: Patients previously received levodopa for ≥6 months as monotherapy/in combination with another dopamine-agonist (DA). Primary variable: Unified PD Rating Scale (UPDRS) Part-II change from baseline to end-of-observation-period (EOP). RESULTS: 91 younger/99 older patients started rotigotine; 68 younger/62 older patients completed the study. Most switched from levodopa+another DA. Addition of rotigotine as first DA was more common in older patients (20.2% vs.15.4%). Mean ± SD rotigotine-exposure: 6.1 ± 3.4 mg/24h younger vs. 4.9 ± 2.4 mg/24h older. Eleven patients changed levodopa dose. At EOP, improvement in mean UPDRS-II was greater in younger patients (p = 0.0289). UPDRS-II responder-rate (≥20% decrease in UPDRS-II score) was higher in younger patients (42.3% vs. 25.9%). Improvement across age groups was similar on PD Sleep Scale-2 and Clinical Global Impressions-Improvement Scale. Adverse drug reactions (ADRs), and discontinuations because of ADRs, were more common among older patients. There were no new safety signals. CONCLUSIONS: Despite low rotigotine doses, when added to levodopa/switched from levodopa+another DA, rotigotine led to greater improvement in UPDRS-II in younger patients (<70 years). Individual patient data revealed clinically meaningful improvements in UPDRS-II in both groups.

Switching from an oral dopamine receptor agonist to rotigotine transdermal patch: a review of clinical data with a focus on patient perspective.

INTRODUCTION: Dopamine receptor agonists (DAs) are commonly used to treat Parkinson's disease (PD) and restless legs syndrome (RLS). In certain situations, switching from oral DAs to rotigotine transdermal patch may be beneficial for the patient (e.g., optimal symptom control/side effects/perioperative management, preference for once-daily/non-oral administration, RLS augmentation treatment). Areas covered: This narrative review summarizes available data on DA dose equivalency, dose conversions, switching schedules, safety, tolerability, efficacy and patient treatment preferences of switching from oral DAs to rotigotine (and vice versa) in patients with PD/RLS. The studies were identified in a PubMed search (up to 8 November 2016) using terms ('dopamine receptor agonist' OR 'rotigotine') AND 'switch'. Expert commentary: Randomized controlled studies often do not address the challenges clinicians face in practice, e.g., switching medications within the same class when dosing is not a one-to-one ratio. The authors describe three open-label studies in PD where oral DAs were successfully switched to rotigotine, and review three studies in RLS where oral DAs/levodopa were switched to rotigotine. Finally, the authors provide a suggested tool for switching from oral DAs to rotigotine, which includes dose conversion factors and switching schedules. The authors' view is that low-dose oral DAs (equivalent to ≤8 mg/24 h rotigotine) may be switched overnight.

Rotigotine transdermal patch in Chinese patients with advanced Parkinson's disease: A randomized, double-blind, placebo-controlled pivotal study.

INTRODUCTION: Rotigotine was demonstrated to be efficacious and well-tolerated in three placebo-controlled studies (CLEOPATRA-PD/PREFER/SP921) of patients with advanced-stage Parkinson's disease (PD), most of whom were Caucasian. This multicenter phase 3 study (SP1037; NCT01646255) was the first to investigate the efficacy and safety of rotigotine in Chinese patients with advanced-stage PD. METHODS: Chinese patients with PD, inadequately controlled on levodopa (stable dose ≥200 mg/day), with ≥2.5 h/day "off" time, and Hoehn & Yahr stage 2-4, were randomized 1:1 to receive transdermal rotigotine or placebo, titrated over ≤7 weeks, maintained at optimal/maximum dose (4-16 mg/24 h) for 12 weeks. Primary efficacy variable: mean change in absolute "off" time (according to patient diaries) from baseline to end of maintenance. Safety variables included adverse events (AEs) and discontinuations due to AEs. RESULTS: 346 patients were randomized and 89.9% completed the study (87.8% placebo; 92.0% rotigotine). All were Chinese (58.7% male; mean ± SD age: 62.2 ± 8.9 years; mean ± SD time since PD diagnosis: 6.62 ± 3.70 years). Rotigotine significantly reduced "off" time vs placebo (LS mean [95% CI] treatment difference: -1.20 h/day [-1.83, -0.57]; p = 0.0002), and resulted in more responders (≥30% decrease in "off" time: 36.9% placebo; 48.8% rotigotine; p = 0.0269). AEs were reported for 86 (50.0%) placebo- and 103 (59.2%) rotigotine-treated patients; 15 discontinued due to AEs (placebo 7; rotigotine 8). The most common AEs (≥5%) were dizziness, nausea, pruritus, and dyskinesia. CONCLUSIONS: Rotigotine was efficacious in Chinese patients with advanced-stage PD as add-on therapy to levodopa, significantly reducing "off" time vs placebo; the treatment difference was similar to that observed in previous studies of mainly Caucasian patients. Rotigotine was generally well-tolerated and had a similar AE profile to those observed in previous studies.