Rationale and Development of Tavapadon, a D1/D5-Selective Partial Dopamine Agonist for the Treatment of Parkinson's Disease.

Currently, available therapeutics for the treatment of Parkinson's disease (PD) fail to provide sustained and predictable relief from motor symptoms without significant risk of adverse events (AEs). While dopaminergic agents, particularly levodopa, may initially provide strong motor control, this efficacy can vary with disease progression. Patients may suffer from motor fluctuations, including sudden and unpredictable drop-offs in efficacy. Dopamine agonists (DAs) are often prescribed during early-stage PD with the expectation they will delay the development of levodopa-associated complications, but currently available DAs are less effective than levodopa for the treatment of motor symptoms. Furthermore, both levodopa and DAs are associated with a significant risk of AEs, many of which can be linked to strong, repeated stimulation of D2/D3 dopamine receptors. Targeting D1/D5 dopamine receptors has been hypothesized to produce strong motor benefits with a reduced risk of D2/D3-related AEs, but the development of D1-selective agonists has been previously hindered by intolerable cardiovascular AEs and poor pharmacokinetic properties. There is therefore an unmet need in PD treatment for therapeutics that provide sustained and predictable efficacy, with strong relief from motor symptoms and reduced risk of AEs. Partial agonism at D1/D5 has shown promise for providing relief from motor symptoms, potentially without the AEs associated with D2/D3-selective DAs and full D1/D5-selective DAs. Tavapadon is a novel oral partial agonist that is highly selective at D1/D5 receptors and could meet these criteria. This review summarizes currently available evidence of tavapadon's therapeutic potential for the treatment of early through advanced PD.

Emraclidine, a novel positive allosteric modulator of cholinergic M4 receptors, for the treatment of schizophrenia: a two-part, randomised, double-blind, placebo-controlled, phase 1b trial.

BACKGROUND: Emraclidine is a novel, brain-penetrant, highly selective M4 receptor positive allosteric modulator in development for the treatment of schizophrenia. We aimed to evaluate the safety and tolerability of multiple ascending doses of emraclidine in patients with schizophrenia. METHODS: We conducted a two-part, randomised, phase 1b trial in the USA. Eligible participants were aged 18-50 years (part A) or 18-55 years (part B) with a primary diagnosis of schizophrenia per the Diagnostic and Statistical Manual of Mental Disorders 5th edition, as confirmed by the Mini International Neuropsychiatric Interview, and extrapyramidal symptom assessments indicating normal to mild symptoms at screening. Part A evaluated the safety and tolerability of emraclidine in five cohorts of participants with stable schizophrenia who received ascending oral doses of emraclidine 5-40 mg (40 mg was administered as 20 mg twice daily) or placebo at a single US site. Part B was a double-blind, randomised, placebo-controlled study that enrolled adults with acute schizophrenia across five US sites; participants were randomly assigned (1:1:1) to receive emraclidine 30 mg once daily, emraclidine 20 mg twice daily, or placebo for 6 weeks (doses established in part A). The primary endpoint was safety and tolerability, assessed in the safety population (participants who received at least one dose of emraclidine or placebo). This trial is now complete and is registered with ClinicalTrials.gov, NCT04136873. FINDINGS: Between Sept 23, 2019, and Sept 17, 2020, 118 patients were assessed for eligibility and 49 were randomly assigned across five cohorts in part A. 44 participants completed the study, with 36 participants receiving emraclidine and eight receiving placebo. The two highest doses tested were selected for part B. Between Oct 12, 2020, and May 7, 2021, 148 patients were assessed for eligibility and 81 were randomly assigned to emraclidine 30 mg once daily (n=27), emraclidine 20 mg twice daily (n=27), or placebo (n=27) in part B. Incidence of adverse events (14 [52%] of 27 participants in the emraclidine 30 mg once daily group, 15 [56%] of 27 in the emraclidine 20 mg twice daily group, and 14 [52%] of 27 in the placebo group), clinical assessments, and weight changes were similar across groups. The most common adverse event was headache (15 [28%] of 54 participants in the emraclidine groups, seven [26%] of 27 in the placebo group). Modest, transient increases in blood pressure and heart rate in emraclidine groups observed at treatment initiation diminished over time and were not considered clinically meaningful by week 6. INTERPRETATION: These data support further investigation of emraclidine as a once-daily treatment for schizophrenia without need for titration and with a potentially favourable side-effect profile. FUNDING: Cerevel Therapeutics.

Levodopa treatment patterns in Parkinson's disease: A retrospective chart review.

BACKGROUND: Medication regimens for Parkinson's disease (PD) may change as the disease progresses, symptoms fluctuate, or medication-related adverse events occur. This study evaluated treatment trends by observation year for patients initially receiving monotherapy with levodopa and a peripheral dopa decarboxylase inhibitor (PDDI). METHODS: In this retrospective chart review, therapy changes were evaluated for patients across the US diagnosed with PD on or before 6/30/2014 who initially received levodopa-PDDI monotherapy. Index date was the first clinic visit. Post-index was any time between the first 31 days after index and study end (6/30/2019). Index Hoehn-Yahr (H-Y) score and medication changes were also analyzed by index low (<400 mg/day) or high (≥400 mg/day) levodopa doses in the levodopa-PDDI combinations. RESULTS: In the levodopa-PDDI cohort (n = 95), there were 0.39 dose escalations, 0.16 dose reductions, 0.12 discontinuations, 0.19 therapy switches, and 0.24 add-ons per patient per year during the study. Most dose escalations or add-ons occurred within the first 6 months post-index. Of those who ever stopped levodopa-PDDI (n = 34), 31 (91%) restarted within the study period. Most (83%) patients who restarted levodopa-PDDI did so in the same year as stopping treatment. Index low dose users were associated with lower H-Y scores, were more inclined to escalate their dose, and were less inclined to reduce their dose in the first 2 years of treatment than index high dose users. CONCLUSIONS: Prescribers and patients tend to experiment with levodopa-PDDI treatment. Although many patients appeared to stop levodopa-PDDI after an initial course of treatment, most subsequently restarted treatment.

Natural history and patterns of treatment change in Parkinson's disease: A retrospective chart review.

BACKGROUND: Parkinson's disease (PD) management seeks to balance the benefits and harms of current medications and evolves as the disease progresses. The natural history of PD and associated patterns of treatment change were analyzed to identify unmet needs in treatment of PD symptoms. METHODS: Medical charts of patients from clinics across the US diagnosed on or before June 30th, 2014 were retrospectively reviewed. Index date was the first clinic visit, and the post-index period was through study end (June 30th, 2019). Outcomes included the frequency of therapy changes in the post-index period, reasons for therapy change, and adverse events (AE). RESULTS: Patients (n = 203) at index were receiving levodopa-peripheral dopa decarboxylase inhibitor (PDDI) monotherapy (47%), dopaminergic agonist (DA) monotherapy (15%), monoamine oxidase B inhibitor (MAOBI) monotherapy (14%), or combination therapies. The percentage of patients in Hoehn-Yahr disease Stage 1-2 was 52% at index and 20% by the end of the study. Frequencies of motor, non-motor, and neuropsychiatric symptoms increased during the enrollment. Levodopa-PDDI monotherapy and levodopa-PDDI + MAOBI had the lowest rates of therapy changes. Symptom relapse was the most common reason for dose escalation, add-on, and dose reduction, whereas AEs were the most common reason for discontinuation and switching. Dose escalation, add-on, and forward switch were most likely to occur in the first 6 months of treatment. CONCLUSIONS: Therapy changes during the study period reflected the challenging and evolving management of PD as the disease progresses. New or add-on symptomatic treatments are needed that are well-tolerated and able to control PD symptoms.

An assessment of Parkinson's disease medication treatment patterns in the Medicaid population.

INTRODUCTION: Most Parkinson's disease (PD) medication adherence studies have focused on patients with commercial or Medicare health insurance coverage. However, less is known regarding medication treatment patterns within the Medicaid population. METHODS: This retrospective cohort study utilized 2011-2019 administrative healthcare claims from 7 state Medicaid programs. We compared newly diagnosed patients with PD started on either levodopa or a dopamine agonist (DA). Baseline comorbidities were compared. Outcomes were assessed during a 12-month post-index observation period, and included total medication days, proportion of days covered (PDC), adherence status, persistence to initiating PD medication, and time to non-persistence of initiating PD medication. RESULTS: Our study sample of 805 Medicaid patients had an average age of 54.1 years, with 52.0% being female. Levodopa was the predominant PD medication at initiation (75.4%). Roughly half of patients had a baseline depressive disorder and nearly 40% had an anxiety disorder. Levodopa patients had a significantly higher PDC compared to DA patients (0.621 vs. 0.546, p = 0.007). An adjusted logistic regression model showed no significant difference in the number of adherent patients between the two groups (p = 0.058). An adjusted Cox proportional hazards model controlling for demographic and baseline variables showed a 26% lower risk of non-persistence for levodopa patients versus DA patients (HR 0.740, CI 0.597-0.917, p = 0.006). CONCLUSIONS: Adherence and persistence rates were suboptimal following initiation of either levodopa or DA medication for patients with PD in Medicaid programs, though rates were better for those initiated on levodopa.

Customized Single-agent Therapy Management of Severe Inflammatory Acne: A Randomized, Double-blind, Parallel-group, Controlled Study of a New Treatment--Adapalene 0.3%-Benzoyl Peroxide 2.5% Gel.

BACKGROUND: More effective therapies are needed in the specific treatment of severe inflammatory acne vulgaris. OBJECTIVES: To demonstrate superior efficacy of adapalene 0.3%-benzoyl peroxide 2.5% gel (0.3% A/BPO) vs. vehicle, and to assess efficacy of 0.3% A/BPO vs. 0.1% A/BPO in subjects with severe inflammatory acne (Investigator's Global Assessment [IGA] of 4) in the context of a larger trial in a moderate and severe population. METHODS: This was a multicenter, randomized, double-blind, parallel-group, 12-week study. Subjects were randomized to receive 0.3% A/BPO, 0.1% A/BPO (benchmark) or vehicle (comparator) once daily for 12 weeks. Co-primary efficacy endpoints were success rate at week 12 (percentage of subjects rated "clear" or "almost clear," ≥ 3-grade IGA improvement), and change in inflammatory (IN) and noninflammatory (NIN) lesion counts from baseline to week 12. Secondary efficacy endpoints were percent changes in IN and NIN lesion counts. Safety endpoints were incidence of adverse events (AEs) and local tolerability signs/symptoms. RESULTS: In the severe inflammatory acne population, a total of 252 subjects were randomized with 106, 112 and 34 subjects in the 0.3% A/BPO, 0.1% A/BPO and vehicle groups, respectively, reaching a high rate of study completion (88.5%). At week 12, both 0.3% A/BPO and 0.1% A/BPO were superior to vehicle in terms of lesion count reduction. However for success rate, only 0.3% A/BPO achieved significantly greater efficacy over vehicle with a treatment difference of 20.1% (31.9% vs. 11.8%; 95% Confidence Interval (CI): [6.0%, 34.2%], P=.029), whereas 0.1% A/BPO did not (treatment difference vs. vehicle of 8.8%; P=.443). This translates to an 11% difference between active treatments in favor of 0.3% A/BPO. Also, 0.3% A/BPO was safe and well tolerated. CONCLUSIONS: Availability of this new treatment option should allow clinicians to better customize severe inflammatory acne management, and the high-strength product provides a step-up treatment when needed.

Erythema of Rosacea: Validation of Patient's Self-Assessment Grading Scale.

BACKGROUND: Facial erythema is a primary feature of rosacea. Currently, no validated scales exist that can accurately capture a patient's self-assessment of their own facial erythema. During phase 2 studies for brimonidine tartrate gel, a 5-point numeric rating scale was developed as a tool to allow subjects to provide an independent assessment of visible changes to the facial erythema associated with their rosacea. OBJECTIVE: The objective of this study was to validate the revised patient's self-assessment (PSA) scale and evaluate it for statistical reliability and validity in quantification of facial erythema of rosacea. METHODS: The validity of the PSA scale was evaluated by assessing the test-retest reliability, construct validity, and known-groups validity based on the data collected during a Phase 2b study on brimonidine gel for the treatment of persistent facial erythema of rosacea. RESULTS: Based on the results of this evaluation, this PSA scale demonstrated test-retest reliability, construct validity, and known-groups validity. LIMITATIONS: Study results are most generalizable to those with moderate to severe erythema. CONCLUSION: The PSA is an appropriate scale to assess facial erythema associated with rosacea.

Reliability of Clinician Erythema Assessment grading scale.

BACKGROUND: Facial erythema is a clinical hallmark of rosacea and often causes social and psychological distress. Although facial erythema assessments are a common endpoint in rosacea clinical trials, their reliability has not been evaluated. OBJECTIVE: The objective of this study was to evaluate the inter- and intrarater reliability of the Clinician's Erythema Assessment (CEA), a 5-point grading scale of facial erythema severity. METHODS: Twelve board-certified dermatologists, previously trained on use of the scale, rated erythema of 28 rosacea subjects twice on the same day. Interrater and intrarater agreement was assessed with the intraclass correlation and κ statistic. RESULTS: The CEA had high interrater reliability and good intrarater reliability with an overall intraclass correlation coefficient (ICC) for session 1 and session 2 of 0.601 and 0.576, respectively; the overall weighted κ statistic for session 1 and session 2 was 0.692. LIMITATIONS: Raters were experienced dermatologists and there may be a risk of recall bias. CONCLUSION: When used by trained raters, CEA is a reliable scale for measuring the facial erythema of rosacea.

Improvement in facial erythema within 30 minutes of initial application of brimonidine tartrate in patients with rosacea.

BACKGROUND: Brimonidine tartrate (BT) 0.5% gel demonstrated significantly greater efficacy versus vehicle gel once-daily for the treatment of moderate to severe erythema of rosacea. OBJECTIVES: To assess the 30-minute speed of onset of topical BT 0.5% gel in reducing facial erythema in Phase III studies as measured by subject and clinician assessments of erythema. METHODS: Two Phase III, randomized, controlled studies with identical design in which subjects with moderate erythema of rosacea (study A: n=260; study B: n=293) were randomized 1:1 to apply topical BT 0.5% or vehicle gel once-daily for 4 weeks. Evaluations included severity of erythema based on Clinician's Erythema Assessment (CEA) and Patient's Self-Assessment (PSA) prior to study drug application and at 30 minutes after application on days 1, 15, and 29. RESULTS: 97.7% and 96.6% of subjects reported normal study completion for studies A and B, respectively. The percentage of subjects achieving a 1-grade improvement in both CEA and PSA was significantly increased at 30 minutes post-dosing with BT 0.5% gel compared to vehicle gel on visit days (day 1: 27.9 vs 6.9%, P <0.001; day 15: 55.9 vs 21.1%, P <0.001; Day 29: 58.3 vs 32.0%, P <0.001 for BT 0.5% gel vs vehicle) in study A. Similar results were shown for study B. CONCLUSIONS: Once-daily topical BT gel 0.5% is not only efficacious at reducing facial erythema but also exhibits response within 30 minutes of application in a significant number of patients throughout both Phase III studies.

Long-term safety and efficacy of once-daily topical brimonidine tartrate gel 0.5% for the treatment of moderate to severe facial erythema of rosacea: results of a 1-year open-label study.

Once-daily topical brimonidine tartrate (BT) gel 0.5% was shown to be efficacious and safe for the treatment of erythema of rosacea in previous studies including a 4-week treatment phase. In the present 1-year study, we aimed to assess the long-term safety and efficacy of the treatment. Subjects with moderate to severe erythema of rosacea were instructed to apply topical BT gel 0.5% once daily for 12 months. Severity of erythema and adverse events (AEs) were evaluated. Approximately 345 subject years of exposure to BT gel 0.5% was achieved in the study. The incidence of AEs and AEs judged to be related to the study drug was higher at the beginning and decreased over the course of the study. Similar safety profiles were observed between the subjects who had received or not received concomitant therapies for the inflammatory lesions of rosacea. Effect of topical BT gel 0.5% on erythema severity was observed after the first application and the durability of the effect was maintained until the end of the study at month 12, with no tachyphylaxis observed. In conclusion, once-daily topical BT gel 0.5% is safe and consistently effective for the long-term treatment of moderate to severe erythema of rosacea, even in the presence of concomitant therapies for the inflammatory lesions of rosacea.

Efficacy and safety of once-daily topical brimonidine tartrate gel 0.5% for the treatment of moderate to severe facial erythema of rosacea: results of two randomized, double-blind, and vehicle-controlled pivotal studies.

BACKGROUND: Brimonidine tartrate, a highly selective α2-adrenergic receptor agonist with potent vasoconstrictive activity, was shown to reduce erythema of rosacea. OBJECTIVE: To assess the efficacy and safety of topical brimonidine tartrate gel 0.5% for the treatment of erythema of rosacea. METHODS: Both studies were randomized, double-blind, and vehicle-controlled, with identical design. Subjects with moderate to severe erythema of rosacea were randomized 1:1 to apply topical brimonidine tartrate gel 0.5% or vehicle gel once-daily for 4 weeks, followed by a 4-week follow-up phase. Evaluations included severity of erythema based on Clinician's Erythema Assessment and Patient's Self-Assessment, as well as adverse events. RESULTS: Topical brimonidine tartrate gel 0.5% was significantly more efficacious than vehicle gel throughout 12 hours on days 1, 15, and 29, with significant difference observed as early as 30 minutes after the first application on day 1 (all P<.001). No tachyphylaxis, rebound or aggravation of other disease signs were observed. Slightly higher incidence of adverse events was observed for topical brimonidine tartrate gel 0.5% than for vehicle; however, most of the adverse events were dermatological, mild, and transient in nature. LIMITATIONS: These data generated in controlled trials may be different from those in clinical practice. CONCLUSIONS: Once-daily brimonidine tartrate gel 0.5% has a good safety profile and provides significantly greater efficacy relative to vehicle gel for the treatment of moderate to severe erythema of rosacea, as early as 30 minutes after application.

Acute treatment with MgSO4 attenuates long-term hippocampal tissue loss after brain trauma in the rat.

Previous studies have shown that magnesium salts and the noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, NPS 1506, attenuated short-term cognitive deficits and histopathological changes associated with traumatic brain injury (TBI). We evaluated the long-term effects of both therapies after brain trauma. Young adult rats were subjected to parasagittal fluid-percussion brain injury and received either MgSO(4) (125 micromol/400 g rat; n = 12) 15 min post-injury, NPS 1506 (1.15 mg/kg; n = 12) 15 min and 4 hr post-injury, or vehicle (n = 9) 15 min post-injury. Uninjured animals (sham) received vehicle (n = 10). Learning function in these animals was evaluated using a water maze paradigm 8 months after injury or sham treatment, and the brains were examined for cortical and hippocampal tissue loss. Compared to sham animals, injured vehicle-treated animals displayed a substantial learning dysfunction, indicated by an increased latency to find a hidden platform in the water maze (P < 0.001). No improvements in learning, however, were found for injured animals treated with NPS 1506 or MgSO(4). Injury induced >30% loss of tissue in the ipsilateral cortex in vehicle-treated animals that was not reduced in animals treated with either NPS 1506 or MgSO(4). Treatment with MgSO(4) significantly reduced progressive tissue loss in the hippocampus (P < 0.001). These findings are the first to demonstrate long-term neuroprotection of hippocampal tissue by an acute treatment in a TBI model. These data also show that the previously reported broad efficacy of MgSO(4) or NPS 1506 observed shortly after brain trauma could not be detected 8 months post-injury.