A Phase I, Randomized, SAD, MAD, and PK Study of Risvodetinib in Older Adults and Parkinson's Disease

Background

Pre-clinical studies suggest that c-Abl activation may play an important role in the etiology of Parkinson's disease, making c-Abl an important target to evaluate for potential disease-modification.

Objective

To assess safety, tolerability, and pharmacokinetics of the c-Abl inhibitor risvodetinib (IkT-148009) in healthy subjects and participants with Parkinson's disease.

Methods

Part 1 (single ascending dose (SAD)) and Part 2 (7-day multiple ascending dose (MAD)) studies were in healthy volunteers. Participants were randomized 3 : 1 across 9 SAD doses and 3 MAD doses of risvodetinib (IkT-148009) or placebo. Part 3 was a MAD study conducted at two doses in 14 participants with mild-to-moderate PD (MAD-PD). Primary outcome measures were safety, tolerability and pharmacokinetics. Exploratory outcomes in PD participants included clinical measures of PD state, GI function, and cerebrospinal fluid (CSF) concentration.

Results

108 patients were treated with no dropouts. The SAD tested doses ranging from 12.5 to 325 mg, while the MAD tested 25 to 200 mg and MAD-PD tested 50 to 100 mg in Parkinson's participants. All active doses had a favorable safety profile with no clinically meaningful adverse events. Single dose pharmacokinetics were approximately linear between 12.5 mg and 200 mg for both Cmax and AUC0 - inf without distinction between healthy volunteers and participants with PD. Exposures at each dose were high relative to other drugs in the same kinase inhibitor class.

Conclusions

Risvodetinib (IkT-148009) was well tolerated, had a favorable safety and pharmacology profile over 7-day dosing, did not induce serious adverse events and did not appear to induce deleterious side-effects in participants administered anti-PD medications.

Validation of a suite of ERP and QEEG biomarkers in a pre-competitive, industry-led study in subjects with schizophrenia and healthy volunteers

OBJECTIVE

Complexity and lack of standardization have mostly limited the use of event-related potentials (ERPs) and quantitative EEG (QEEG) biomarkers in drug development to small early phase trials. We present results from a clinical study on healthy volunteers (HV) and patients with schizophrenia (SZ) that assessed test-retest, group differences, variance, and correlation with functional assessments for ERP and QEEG measures collected at clinical and commercial trial sites with standardized instrumentation and methods, and analyzed through an automated data analysis pipeline.

METHODS

81 HV and 80 SZ were tested at one of four study sites. Subjects were administered two ERP/EEG testing sessions on separate visits. Sessions included a mismatch negativity paradigm, a 40 Hz auditory steady-state response paradigm, an eyes-closed resting state EEG, and an active auditory oddball paradigm. SZ subjects were also tested on the Brief Assessment of Cognition (BAC), Positive and Negative Syndrome Scale (PANSS), and Virtual Reality Functional Capacity Assessment Tool (VRFCAT).

RESULTS

Standardized ERP/EEG instrumentation and methods ensured few test failures. The automated data analysis pipeline allowed for near real-time analysis with no human intervention. Test-retest reliability was fair-to-excellent for most of the outcome measures. SZ subjects showed significant deficits in ERP and QEEG measures consistent with published academic literature. A subset of ERP and QEEG measures correlated with functional assessments administered to the SZ subjects.

CONCLUSIONS

With standardized instrumentation and methods, complex ERP/EEG testing sessions can be reliably performed at clinical and commercial trial sites to produce high-quality data in near real-time.

Experimental Medicine Approaches in Early-Phase CNS Drug Development

Traditionally, Phase 1 clinical trials were largely conducted in healthy normal volunteers and focused on collection of safety, tolerability, and pharmacokinetic data. However, in the CNS therapeutic area, with more drugs failing in later phase development, Phase 1 trials have undergone an evolution that includes incorporation of novel approaches involving novel study designs, inclusion of biomarkers, and early inclusion of patients to improve the pharmacologic understanding of novel CNS-active compounds early in clinical development with the hope of improving success in later phase pivotal trials. In this chapter, the authors will discuss the changing landscape of Phase 1 clinical trials in CNS, including novel trial methodology, inclusion of pharmacodynamic biomarkers, and experimental medicine approaches to inform early decision-making in clinical development.

A Framework for Developing Pharmacotherapy for Agitation in Alzheimer's Disease: Recommendations of the ISCTM* Working Group

Dementia is characterized by a significant decline in one of several cognitive domains such as memory, language and executive function, affecting independence and representing a significant deterioration from a previous level of functioning (1). Alzheimer’s Disease (AD) represents the most common form of dementia and contributes up to 70% of the almost 50 million dementia cases worldwide, a number that is projected to double in 20 years (2).

Diagnostic criteria for apathy in neurocognitive disorders

INTRODUCTION

Apathy is common in neurocognitive disorders (NCD) but NCD-specific diagnostic criteria are needed.

METHODS

The International Society for CNS Clinical Trials Methodology Apathy Work Group convened an expert group and sought input from academia, health-care, industry, and regulatory bodies. A modified Delphi methodology was followed, and included an extensive literature review, two surveys, and two meetings at international conferences, culminating in a consensus meeting in 2019.

RESULTS

The final criteria reached consensus with more than 80% agreement on all parts and included: limited to people with NCD; symptoms persistent or frequently recurrent over at least 4 weeks, a change from the patient's usual behavior, and including one of the following: diminished initiative, diminished interest, or diminished emotional expression/responsiveness; causing significant functional impairment and not exclusively explained by other etiologies.

DISCUSSION

These criteria provide a framework for defining apathy as a unique clinical construct in NCD for diagnosis and further research.

Cost-effectiveness of vortioxetine compared with levomilnacipran and vilazodone in patients with major depressive disorder switching from an initial antidepressant

Introduction: Many patients with major depressive disorder (MDD) do not achieve remission with their first antidepressant (AD), resulting in a high burden due to treatment failure. Vortioxetine is a valid treatment option for patients with MDD only partially responding to their first AD. Characterization of vortioxetine's potential benefits versus other approved treatments is important. Areas covered: The cost-effectiveness of vortioxetine, including cognitive outcomes, was modeled in comparison with levomilnacipran and vilazodone for patients switched to these medications after inadequate responses to a first AD. Expert opinion: Vortioxetine was associated with incremental quality-adjusted life-year (QALY) gains versus levomilnacipran (0.008) or vilazodone (0.009). Vortioxetine was dominant versus levomilnacipran and cost-effective versus vilazodone (incremental cost-effectiveness ratio [ICER],33,829 USD/QALY). In sensitivity analyses using residual cognitive dysfunction rates (vortioxetine, 49%; levomilnacipran, 58%, and vilazodone, 64%), incremental QALY gains for vortioxetine versus levomilnacipran (0.0085) or vilazodone (0.0109) were found. Vortioxetine remained dominant versus levomilnacipran and cost-effective versus vilazodone (ICER, 27,633 USD/QALY). ICER reduction was found with cognition outcomes inclusion. This model provides additional support for considering vortioxetine for patients requiring a switch of MDD treatments, although its conclusions are limited by the data available for inclusion. Additional research and real-world trials are needed to confirm the findings.

Candidate inflammatory biomarkers display unique relationships with alpha-synuclein and correlate with measures of disease severity in subjects with Parkinson's disease

Background

Efforts to identify fluid biomarkers of Parkinson’s disease (PD) have intensified in the last decade. As the role of inflammation in PD pathophysiology becomes increasingly recognized, investigators aim to define inflammatory signatures to help elucidate underlying mechanisms of disease pathogenesis and aid in identification of patients with inflammatory endophenotypes that could benefit from immunomodulatory interventions. However, discordant results in the literature and a lack of information regarding the stability of inflammatory factors over a 24-h period have hampered progress.

Methods

Here, we measured inflammatory proteins in serum and CSF of a small cohort of PD (n = 12) and age-matched healthy control (HC) subjects (n = 6) at 11 time points across 24 h to (1) identify potential diurnal variation, (2) reveal differences in PD vs HC, and (3) to correlate with CSF levels of amyloid β (Aβ) and α-synuclein in an effort to generate data-driven hypotheses regarding candidate biomarkers of PD.

Results

Despite significant variability in other factors, a repeated measures two-way analysis of variance by time and disease state for each analyte revealed that serum IFNγ, TNF, and neutrophil gelatinase-associated lipocalin (NGAL) were stable across 24 h and different between HC and PD. Regression analysis revealed that C-reactive protein (CRP) was the only factor with a strong linear relationship between CSF and serum. PD and HC subjects showed significantly different relationships between CSF Aβ proteins and α-synuclein and specific inflammatory factors, and CSF IFNγ and serum IL-8 positively correlated with clinical measures of PD. Finally, linear discriminant analysis revealed that serum TNF and CSF α-synuclein discriminated between PD and HC with a minimum of 82% sensitivity and 83% specificity.

Conclusions

Our findings identify a panel of inflammatory factors in serum and CSF that can be reliably measured, distinguish between PD and HC, and monitor inflammation as disease progresses or in response to interventional therapies. This panel may aid in generating hypotheses and feasible experimental designs towards identifying biomarkers of neurodegenerative disease by focusing on analytes that remain stable regardless of time of sample collection.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-017-0935-1) contains supplementary material, which is available to authorized users.

A Phase 1B, randomized, double blind, placebo controlled, multiple-dose escalation study of NSI-189 phosphate, a neurogenic compound, in depressed patients

We wanted to examine tolerability and efficacy of NSI-189, a benzylpiperizine-aminiopyridine neurogenic compound for treating major depressive disorder (MDD). This was a Phase 1B, double blind, randomized, placebo controlled, multiple-dose study with three cohorts. The first cohort received 40 mg q.d. (n=6) or placebo (n=2), the second cohort 40 mg b.i.d. (n=6) or placebo (n=2), and the third cohort 40 mg t.i.d. (n=6) or placebo (n=2). Twenty-four patients with MDD were recruited, with the diagnosis and severity confirmed through remote interviews. Eligible patients received NSI-189 or placebo for 28 days in an inpatient setting with assessments for safety, pharmacokinetics (PK) and efficacy. Outpatient follow-up visits were conducted until day 84 (±3). NSI-189 was relatively well tolerated at all doses, with no serious adverse effects. NSI-189 area under the curve increased in a dose-related and nearly proportional manner across the three cohorts, with a half-life of 17.4-20.5 h. The exploratory efficacy measurements, including Symptoms Of Depression Questionnaire (SDQ), Montgomery-Asberg Depression Scale (MADRS), Clinical Global Impressions-Improvement (CGI-I), and The Massachusetts General Hospital (MGH) Cognitive and Physical Functioning Questionnaire (CPFQ) showed a promising reduction in depressive and cognitive symptoms across all measures for NSI-189, with significant improvement in the SDQ and CPFQ, and a medium to large effect size for all measures. These improvements persisted during the follow-up phase. In summary, NSI-189 shows potential as a treatment for MDD in an early phase study. The main limitation of this preliminary study was the small sample size of each cohort.

Lurasidone drug-drug interaction studies: a comprehensive review

BACKGROUND

To evaluate potential drug-drug interactions with the atypical antipsychotic lurasidone.

METHODS

Seven phase I studies were conducted to investigate the effects of repeated dosing of ketoconazole, diltiazem, rifampin, or lithium on the pharmacokinetics (PK) of single oral doses of lurasidone, or the effects of repeated dosing of lurasidone on the PK of digoxin, midazolam, or the oral contraceptive norgestimate/ethinyl estradiol. Two 6-week, phase III studies included evaluation of the potential for interaction between lurasidone and lithium or valproate. Maximum serum or plasma concentration (Cmax) and area under the concentration-time curve (AUC) were calculated.

RESULTS

Concomitant ketoconazole administration resulted in a 6.8-fold increase in lurasidone Cmax and a 9.3-fold increase in lurasidone AUC; concomitant diltiazem administration resulted in 2.1- and 2.2-fold increases, respectively. Rifampin decreased lurasidone Cmax and AUC (one-seventh and one-fifth of lurasidone alone, respectively). Steady-state dosing with lurasidone increased Cmax and AUC0-24 (AUC from time 0 to 24 h postdose) of digoxin by 9% and 13%, respectively, and of midazolam by 21% and 44%, respectively. There were no significant interactions between lurasidone and lithium, valproate, ethinyl estradiol, or norelgestromin (the major active metabolite of norgestimate).

CONCLUSIONS

Lurasidone PK is altered by strong cytochrome P450 (CYP) 3A4 inhibitors or inducers, and coadministration is contraindicated; whereas moderate CYP3A4 inhibitors have less effect, and lurasidone dosage restrictions are recommended. No dose adjustment for lurasidone is needed when administered with lithium or valproate. Dose adjustment is not required for lithium, valproate, digoxin (a P-glycoprotein substrate), or midazolam or oral contraceptives (CYP3A4 substrates) when coadministered with lurasidone.

Relative efficacy and tolerability of vortioxetine versus selected antidepressants by indirect comparisons of similar clinical studies

INTRODUCTION

Vortioxetine is an antidepressant with multimodal activity which has shown efficacy in major depressive disorder (MDD) patients in six of ten short-term, randomized, placebo-controlled trials (completed end 2012).

METHODS

We performed meta-regression analyses to indirectly compare vortioxetine to seven marketed antidepressants with different mechanisms of action. To ensure study comparability, only experimental drug and placebo arms from placebo-controlled registration studies were included in primary analyses. The main outcomes were efficacy (standardized mean difference in change from baseline to 2 months on primary endpoint [MADRS/HAM-D]), and tolerability (withdrawal rate due to adverse events).

RESULTS

For efficacy, estimates of treatment effect (negative estimates favor vortioxetine) for vortioxetine versus comparators were: agomelatine, -0.16 (p = 0.11); desvenlafaxine, 0.03 (p = 0.80); duloxetine, 0.09 (p = 0.42); escitalopram, -0.05 (p = 0.70); sertraline, -0.04 (p = 0.83); venlafaxine IR/XR, 0.12 (p = 0.33); and vilazodone, -0.25 (p = 0.11). For tolerability, all but one combination was numerically in favor of vortioxetine (odds ratio < 1), although not all differences were statistically significant: agomelatine, 1.77 (p = 0.03); desvenlafaxine, 0.58 (p = 0.04); duloxetine, 0.75 (p = 0.26); escitalopram, 0.67 (p = 0.28); sertraline, 0.30 (p = 0.01); venlafaxine, 0.47 (p = 0.01); and vilazodone, 0.64 (p = 0.18). Sensitivity analyses did not significantly alter antidepressant effect estimates or relative ranking.

CONCLUSION

These meta-regression data show that vortioxetine offers a comparable or favorable combination of efficacy (measured by MADRS/HAM-D) and tolerability (measured by withdrawal rate due to adverse events) versus other antidepressants in registration studies in MDD. Alternative methods like mixed-treatment comparison and inclusion of all randomized studies and active reference arms may provide complementary information to this analysis (more evidence but also more heterogeneity). Key messages: Indirect comparisons based on registration studies allow a useful comparison between a recently approved antidepressant and an approved drug. Vortioxetine offers a comparable or favorable combination of efficacy (measured by MADRS/HAM-D assessments) and tolerability (measured by withdrawal rate due to adverse events) versus other antidepressants in registration studies in MDD.

Use of translational pharmacodynamic biomarkers in early-phase clinical studies for schizophrenia

Schizophrenia is a severe mental disorder characterized by cognitive deficits, and positive and negative symptoms. The development of effective pharmacological compounds for the treatment of schizophrenia has proven challenging and costly, with many compounds failing during clinical trials. Many failures occur due to disease heterogeneity and lack of predictive preclinical models and biomarkers that readily translate to humans during early characterization of novel antipsychotic compounds. Traditional early-phase trials consist of single- or multiple-dose designs aimed at determining the safety and tolerability of an investigational compound in healthy volunteers. However, by incorporating a translational approach employing methodologies derived from preclinical studies, such as EEG measures and imaging, into the traditional Phase I program, critical information regarding a compound's dose-response effects on pharmacodynamic biomarkers can be acquired. Furthermore, combined with the use of patients with stable schizophrenia in early-phase clinical trials, significant 'de-risking' and more confident 'go/no-go' decisions are possible.

Effect of food on the pharmacokinetics of lurasidone: results of two randomized, open-label, crossover studies

OBJECTIVE

This study aimed to investigate the effect of prandial status and caloric and fat composition of meals on the pharmacokinetics of lurasidone.

METHODS

Two randomized, open-label, crossover studies were conducted in clinically stable adults with schizophrenia or schizoaffective disorder. Study 1 (n = 16) evaluated the effect of fasting and three meal types (100 kcal/medium fat, 200 kcal/medium fat, and 800-1000 kcal/high fat), and Study 2 (n = 26) evaluated the effect of fasting and five meal types (350 kcal/high fat, 500 kcal/low fat, 500 kcal/high fat, 800-1000 kcal/low fat, and 800-1000 kcal/high fat) on the bioavailability of lurasidone. Subjects received lurasidone 120 mg once daily. Maximum serum concentration (Cmax ) and area under the serum concentration-time curve over the dosing interval (AUC0-tau ) were determined on Day 5 for each meal type.

RESULTS

In Study 1, the geometric mean Cmax in the fasted state was 56.7 ng/mL compared with 123.0 ng/mL for the 800- to 1000-kcal meal; mean AUC0-tau was 360.0 versus 752.4 ng·h/mL (both p < 0.001). Lurasidone exposure following meals containing 100 and 200 kcal was substantially lower than with meals containing 800-1000 kcal. In Study 2, the geometric mean Cmax was 52.9 ng/mL in the fasted state, 161 ng/mL for the 350-kcal/high-fat meal, 135 ng/mL for the 500-kcal/high-fat meal, and 131 ng/mL for the 800- to 1000-kcal/high-fat meal; mean AUC0-tau was 390, 743, 727, and 769 ng·h/mL, respectively. For all comparisons, the 90% confidence interval of the fed to fasted ratios indicated nonequivalence. Lurasidone exposure was similar following meals containing 350-1000 kcal and was independent of fat content.

CONCLUSION

Lurasidone should be administered with food-at least 350 kcal-to ensure maximum exposure.

Multiple-Dose Plasma Pharmacokinetic and Safety Study of LY450108 and LY451395 (AMPA Receptor Potentiators) and Their Concentration in Cerebrospinal Fluid in Healthy Human Subjects

The objective of this study was to measure the steady-state cerebrospinal fluid (CSF) concentration of LY450108 and LY451395 (positive modulators of AMPA receptors) in healthy subjects after the administration of 1 mg and 5 mg. Secondary objectives included the evaluation of safety, pharmacokinetics, and steady-state ratio of plasma:CSF concentrations of LY450108 and LY451395 after multiple dosing. This study was an open-label, multiple oral dose study evaluating 1 mg and 5 mg LY450108 and 1 mg and 5 mg LY451395 in 12 (3 subjects per dosing group) healthy subjects, aged 18 to 49 years. Twelve healthy male subjects completed the study. LY450108 and LY451395 were quantifiable in CSF after 1-mg and 5-mg multiple-dose administrations with plasma:CSF ratio of 82:1 and 44:1, respectively. LY450108 and LY451395 1 mg and 5 mg were measured in the CSF. Single and multiple oral doses of LY450108 and LY451395 were determined to be safe and well tolerated in healthy subjects.

Pharmacokinetic and Pharmacodynamic Interactions of Oral Midazolam with Ketoconazole, Fluoxetine, Fluvoxamine, and Nefazodone

The objective of this study was to investigate pharmacokinetic and pharmacodynamic interactions between midazolam and fluoxetine, fluvoxamine, nefazodone, and ketoconazole. Forty healthy subjects were randomized to receive one of the four study drugs for 12 days in a parallel study design: fluoxetine 60 mg per day for 5 days, followed by 20 mg per day for 7 days; fluvoxamine titrated to a daily dose of 200 mg; nefazodone titrated to a daily dose of 400 mg; or ketoconazole 200 mg per day. All 40 subjects received oral midazolam solution before and after the 12-day study drug regimen. Blood samples for determination of midazolam concentrations were drawn for 24 hours after each midazolam dose and used for the calculation of pharmacokinetic parameters. The effects of the study drugs on midazolam pharmacodynamics were assessed using the symbol digit modalities test (SDMT). The mean area under the curve (AUC) for midazolam was increased 771.9% by ketoconazole and 444.0% by nefazodone administration. However, there was no significant change in midazolam AUC as a result of fluoxetine (13.4% decrease) and a statistical trend for fluvoxamine (66.1% increase) administration. Pharmacodynamic data are consistent with pharmacokinetic data indicating that nefazodone and ketoconazole resulted in significant increases in midazolam-related cognition impairment. The significant impairment in subjects' cognitive function reflects the changes in midazolam clearance after treatment with ketoconazole and nefazodone. These results suggest that caution with the use of midazolam is warranted with potent CYP3A4 inhibitors.

Maximum tolerated dose evaluation of the AMPA modulator Org 26576 in healthy volunteers and depressed patients: a summary and method analysis of bridging research in support of phase II dose selection

BACKGROUND

A key challenge to dose selection in early central nervous system (CNS) clinical drug development is that patient tolerability profiles often differ from those of healthy volunteers (HVs), yet HVs are the modal population for determining doses to be investigated in phase II trials. Without clear tolerability data from the target patient population, first efficacy trials may include doses that are either too high or too low, creating undue risk for study participants and the development program overall. Bridging trials address this challenge by carefully investigating safety and tolerability in the target population prior to full-scale proof-of-concept trials.

OBJECTIVE

Org 26576 is an alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor positive allosteric modulator that acts by modulating ionotropic AMPA-type glutamate receptors to enhance glutamatergic neurotransmission. In preparation for phase II efficacy trials in major depressive disorder (MDD), two separate phase I trials were conducted to evaluate safety, tolerability, and pharmacokinetics in HVs and in the target patient population.

METHODS

Both trials were randomized and placebo controlled, and included multiple rising-dose cohorts (HV range 100-400 mg bid; MDD range 100-600 mg bid). HVs (n = 36) and patients with MDD (n = 54) were dosed under similarly controlled conditions in an inpatient facility, HVs for up to 14 days and MDD patients for up to 28 days. Safety, tolerability, and pharmacokinetics were assessed frequently.

RESULTS

Despite comparable pharmacokinetic profiles, the maximum tolerated dose (MTD) in depressed patients was 450 mg bid, twice the MTD established in HVs. No clinically relevant safety issues associated with Org 26576 were noted.

CONCLUSION

This article presents safety, tolerability, and pharmacokinetic data from two different populations examined under similar dosing conditions. The important implications of such bridging work in phase II dose selection are discussed, as are study design and data interpretation challenges.

Examination of Org 26576, an AMPA receptor positive allosteric modulator, in patients diagnosed with major depressive disorder: an exploratory, randomized, double-blind, placebo-controlled trial

Org 26576 acts by modulating ionotropic AMPA-type glutamate receptors to enhance glutamatergic neurotransmission. The aim of this Phase 1b study (N=54) was to explore safety, tolerability, pharmacokinetics, and pharmacodynamics of Org 26576 in depressed patients. Part I (N=24) evaluated the maximum tolerated dose (MTD) and optimal titration schedule in a multiple rising dose paradigm (range 100 mg BID to 600 mg BID); Part II (N=30) utilized a parallel groups design (100 mg BID, 400 mg BID, placebo) to examine all endpoints over a 28-day dosing period. Based on the number of moderate intensity adverse events reported at the 600 mg BID dose level, the MTD established in Part I was 450 mg BID. Symptomatic improvement as measured by the Montgomery-Asberg Depression Rating Scale was numerically greater in the Org 26576 groups than in the placebo group in both study parts. In Part II, the 400 mg BID dose was associated with improvements in executive functioning and speed of processing cognitive tests. Org 26576 was also associated with growth hormone increases and cortisol decreases at the end of treatment but did not influence prolactin or brain-derived neurotrophic factor. The quantitative electroencephalogram index Antidepressant Treatment Response at Week 1 was able to significantly predict symptomatic response at endpoint in the active treatment group, as was early improvement in social acuity. Overall, Org 26576 demonstrated good tolerability and pharmacokinetic properties in depressed patients, and pharmacodynamic endpoints suggested that it may show promise in future well-controlled, adequately powered proof of concept trials.

Clinically significant psychotropic drug-drug interactions in the primary care setting

In recent years, the growing numbers of patients seeking care for a wide range of psychiatric illnesses in the primary care setting has resulted in an increase in the number of psychotropic medications prescribed. Along with the increased utilization of psychotropic medications, considerable variability is noted in the prescribing patterns of primary care providers and psychiatrists. Because psychiatric patients also suffer from a number of additional medical comorbidities, the increased utilization of psychotropic medications presents an elevated risk of clinically significant drug interactions in these patients. While life-threatening drug interactions are rare, clinically significant drug interactions impacting drug response or appearance of serious adverse drug reactions have been documented and can impact long-term outcomes. Additionally, the impact of genetic variability on the psychotropic drug's pharmacodynamics and/or pharmacokinetics may further complicate drug therapy. Increased awareness of clinically relevant psychotropic drug interactions can aid clinicians to achieve optimal therapeutic outcomes in patients in the primary care setting.

Robust central reduction of amyloid-β in humans with an orally available, non-peptidic β-secretase inhibitor

According to the amyloid cascade hypothesis, cerebral deposition of amyloid-β peptide (Aβ) is critical for Alzheimer's disease (AD) pathogenesis. Aβ generation is initiated when β-secretase (BACE1) cleaves the amyloid precursor protein. For more than a decade, BACE1 has been a prime target for designing drugs to prevent or treat AD. However, development of such agents has turned out to be extremely challenging, with major hurdles in cell penetration, oral bioavailability/metabolic clearance, and brain access. Using a fragment-based chemistry strategy, we have generated LY2811376 [(S)-4-(2,4-difluoro-5-pyrimidin-5-yl-phenyl)-4-methyl-5,6-dihydro-4H-[1,3]thiazin-2-ylamine], the first orally available non-peptidic BACE1 inhibitor that produces profound Aβ-lowering effects in animals. The biomarker changes obtained in preclinical animal models translate into man at doses of LY2811376 that were safe and well tolerated in healthy volunteers. Prominent and long-lasting Aβ reductions in lumbar CSF were measured after oral dosing of 30 or 90 mg of LY2811376. This represents the first translation of BACE1-driven biomarker changes in CNS from preclinical animal models to man. Because of toxicology findings identified in longer-term preclinical studies, this compound is no longer progressing in clinical development. However, BACE1 remains a viable target because the adverse effects reported here were recapitulated in LY2811376-treated BACE1 KO mice and thus are unrelated to BACE1 inhibition. The magnitude and duration of central Aβ reduction obtainable with BACE1 inhibition positions this protease as a tractable small-molecule target through which to test the amyloid hypothesis in man.

Cerebrospinal fluid beta-amyloid and dynabridging in Alzheimer's disease drug development

Cerebrospinal fluid (CSF) has become a matrix for biomarker discovery and development in recent years. A number of biomarkers for pathogenic processes in Alzheimer's disease have been identified. Studies have revealed the diagnostic potential of CSF amyloid-beta, tau and phosphorylated tau levels. California Clinical Trials has conducted a number of studies in collaboration with drug developers that demonstrate the importance of CSF amyloid-beta peptides as biomarkers for drug development. These studies also establish the utility of CSF sampling via continuous indwelling lumbar catheterization (dynabridging) for assessing pharmacokinetic and pharmacodynamic parameters in conjunction with biomarker analysis. Corroborative approaches using multiple biomarker methods including neuroimaging and CSF biomarkers will provide a complete picture of the Alzheimer's disease brain.

What is causing the reduced drug-placebo difference in recent schizophrenia clinical trials and what can be done about it?

On September 18, 2007, a collaborative session between the International Society for CNS Clinical Trials and Methodology and the International Society for CNS Drug Development was held in Brussels, Belgium. Both groups, with membership from industry, academia, and governmental and nongovernmental agencies, have been formed to address scientific, clinical, regulatory, and methodological challenges in the development of central nervous system therapeutic agents. The focus of this joint session was the apparent diminution of drug-placebo differences in recent multicenter trials of antipsychotic medications for schizophrenia. To characterize the nature of the problem, some presenters reported data from several recent trials that indicated higher rates of placebo response and lower rates of drug response (even to previously established, comparator drugs), when compared with earlier trials. As a means to identify the possible causes of the problem, discussions covered a range of methodological factors such as participant characteristics, trial designs, site characteristics, clinical setting (inpatient vs outpatient), inclusion/exclusion criteria, and diagnostic specificity. Finally, possible solutions were discussed, such as improving precision of participant selection criteria, improving assessment instruments and/or assessment methodology to increase reliability of outcome measures, innovative methods to encourage greater subject adherence and investigator involvement, improved rater training and accountability metrics at clinical sites to increase quality assurance, and advanced methods of pharmacokinetic/pharmacodynamic modeling to optimize dosing prior to initiating large phase 3 trials. The session closed with a roundtable discussion and recommendations for data sharing to further explore potential causes and viable solutions to be applied in future trials.

The 6-month persistence on SSRIs and associated economic burden

OBJECTIVES

To assess persistence on SSRIs (most prescribed antidepressants) and associated healthcare costs in a naturalistic setting.

METHODS

For this retrospective cohort study based on a US reimbursement claims database, all adults with a claim for a SSRI (citalopram, escitalopram, fluoxetine, paroxetine or sertraline) related to a diagnosis of depression were included. Patients should have had no previous reimbursement for any antidepressant within the previous 6 months. Non-persistence was defined as failing to renew prescription within 30 days in the 6-month period after the index date.

RESULTS

In the 45,481 patients included, persistence decreased from 95.5% at 1 month, to 52.6% at 2 months, 37.6% at 3 months and 18.9% at 6 months. Among factors associated with higher 6-month persistence were age 18-34 years, physician's specialty, treatment with escitalopram, absence of abuse history and psychotropic prescription history. During the 6-month after index date, healthcare costs tended to be higher in non-persistent than in persistent patients although not significantly (RR=1.05, adjusted p=0.055).

CONCLUSION

Despite some limitations associated with the use of computerized administrative claims data (residual unmeasured confounding), these results highlight a generally low persistence rate at 6 months. Special attention should be given to persistence on treatment, with consideration of potential antidepressant impact.

Drug-drug interactions with the use of psychotropic medications. Interview by Diane M. Sloan

Drug interactions with psychotropics can result in poor tolerability or reduced efficacy, or both, which can negatively impact patient outcomes. Most drug interactions with psychotropics are pharmacokinetic and involve the CYP family of enzymes. Clinicians can improve outcomes for patients by considering the potential for DDIs when selecting a specific psychotropic, and when evaluating patient progress, compliance, and the incidence of AEs throughout the course of treatment. Resources for clinicians include internet databases, software programs, package inserts, and consultation with pharmacists.

Efficacy and safety of doxepin 1 mg, 3 mg, and 6 mg in elderly patients with primary insomnia: a randomized, double-blind, placebo-controlled crossover study

OBJECTIVES

Evaluate efficacy and safety of the histamine-H1 antagonist doxepin at doses of 1 mg, 3 mg, and 6 mg in elderly adults with primary insomnia.

DESIGN

A randomized, double-blind, placebo-controlled, crossover design was used in this population of elderly adults with primary insomnia (DSM-IV). Each treatment period consisted of 2 polysomnographic (PSG) assessment nights with a 5- or 12-day drug-free interval between periods. The study was conducted from September 2004 to January 2005.

SETTING

Sleep laboratories in 11 sleep centers in the United States.

PARTICIPANTS

Elderly adults with primary insomnia.

INTERVENTION

Doxepin 1 mg, 3 mg, and 6 mg.

MEASUREMENTS

Efficacy was assessed using PSG and patient-reported measures.

RESULTS

Seventy-six patients were randomly assigned. All 3 doxepin doses produced dose-related significant improvements in PSG-determined wake time during sleep (p < .0001), wake time after sleep onset (p < .0001), total sleep time (p < .0001), and overall sleep efficiency (p < .0001) versus placebo. At the 3-mg and 6-mg doses, sleep efficiency was significantly improved during all thirds of the night (p < .05). There was a dose-related decrease in patient-reported sleep latency, with the 6-mg dose achieving statistical significance in latency to sleep onset (p = .0181). The pattern of the remaining subjective efficacy results was consistent with PSG. All 3 doxepin doses had side effect profiles comparable to placebo, with no spontaneously reported anticholinergic effects, no memory impairment, and no significant next-day residual effects.

CONCLUSIONS

In this 2-night study of elderly adults with primary insomnia, doxepin doses of 1 mg, 3 mg, and 6 mg were well tolerated and produced significant improvement in objective and subjective sleep maintenance and duration endpoints that persisted into the final hour of the night. Positive effects on patient-reported sleep onset were observed at the highest dose. All 3 doxepin doses had a safety profile comparable to placebo. These data demonstrate that doxepin was efficacious in improving sleep in elderly adults.

The use of individually tailored environmental supports to improve medication adherence and outcomes in schizophrenia

Cognitive adaptation training (CAT) is a psychosocial treatment that uses environmental supports such as signs, checklists, alarms, and the organization of belongings to cue and sequence adaptive behaviors in the home. Ninety-five outpatients with schizophrenia (structured clinical interview for diagnosis, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) were randomly assigned to (1) Full-CAT (CAT focused on many aspects of community adaptation including grooming, care of living quarters, leisure skills, social and role performance, and medication adherence), (2) Pharm-CAT (CAT focused only on medication and appointment adherence), or (3) treatment as usual (TAU). Treatment lasted for 9 months, and patients were followed for 6 months after the withdrawal of home visits. Medication adherence (assessed during unannounced, in-home pill counts) and functional outcomes were assessed at 3-month intervals. Results of mixed-effects regression models indicated that both CAT and Pharm-CAT treatments were superior to TAU for improving adherence to prescribed medication (P < .0001). Effects on medication adherence remained significant when home visits were withdrawn. Full-CAT treatment improved functional outcome relative to Pharm-CAT and TAU (P < .0001). However, differences for functional outcome across groups decreased following the withdrawal of home visits and were no longer statistically significant at the 6-month follow-up. Survival time to relapse or significant exacerbation was significantly longer in both CAT and Pharm-CAT in comparison to TAU (.004). Findings indicate that supports targeting medication adherence can improve and maintain this behavior. Comprehensive supports targeting multiple domains of functioning are necessary to improve functional outcomes. Maintenance of gains in functional outcome may require some form of continued intervention.

Relationships among subjective and objective measures of adherence to oral antipsychotic medications

OBJECTIVE

The most common ways of assessing adherence to oral antipsychotic medications in research and in clinical practice are self-report and physician report. This prospective study examined the agreement among measures of adherence to oral antipsychotic medications among 52 outpatients with schizophrenia.

METHODS

Participants were assessed at baseline during a visit to their outpatient clinic and followed for 12 weeks. Adherence was assessed by using subjective measures (self-report and physician report) and objective measures (pill counts conducted in the home, electronic monitoring, and blood plasma concentrations). Electronic monitoring was used as an imperfect standard against which other methods were judged.

RESULTS

Data from pill counts and from electronic monitoring were strongly correlated (r(k)=.61). Self-report and physicians' ratings of compliance were weakly correlated with pill count and electronic monitoring when compliance scores were examined with rank-order correlations (r(k)=.18-.32). When the sample was dichotomized into adherent and nonadherent groups on the basis of electronic monitoring or pill count (at least 80% adherent), neither physicians nor patients identified adherent behavior (kappa<or=20). Blood plasma concentrations were not correlated with any other measures of adherence (kappa<or=20). Self-report and physician report were best correlated with clinical state (r(k)=-.27, r(k)=-.25), suggesting that patients and treating professionals may use clinical state to estimate adherence.

CONCLUSIONS

Patients and physicians were not able to identify adherence. The inability of physicians to accurately identify adherent individuals is likely to have important consequences for prescribing behavior, health care costs, and patient outcomes.

The effects of supratherapeutic doses of duloxetine on blood pressure and pulse rate

The effects of supratherapeutic dosages of duloxetine, a serotonin and norepinephrine reuptake inhibitor, on blood pressure and pulse rate were assessed in a multicenter, double-blind, randomized, placebo-controlled, crossover study in 117 healthy women aged 19 to 74 years. Dosages were escalated from 60 mg twice daily (BID) to 200 mg BID over 16 days. Vital signs were monitored at baseline, before morning dosing, and sequentially at steady state. Duloxetine produced increases in supine systolic and diastolic blood pressures, which reached maximums of approximately 12 mm Hg and approximately 7 mm Hg above baseline, respectively, during dosing at 120 mg BID and then stabilized. Supine pulse rate increased gradually with dose, reaching 10 to 12 bpm above baseline after 4 days of dosing at 200 mg BID. Duloxetine caused changes in orthostatic blood pressures and pulse rate that reached plateau values after 3 to 4 days of dosing at 160 mg BID and were generally not associated with subjectively reported orthostatic-related adverse events. All vital signs normalized by 1 to 2 days after study drug discontinuation. Prehypertensive subjects may become hypertensive upon initial duloxetine dosing, but this can be predicted from predose blood pressure. Short-term supratherapeutic duloxetine dosages up to 200 mg BID are not well tolerated but are generally not associated with severe, clinically important adverse events. Overall, the types of adverse events reported in this study were similar to those in other studies of duloxetine in healthy subjects.

Pharmacokinetics and pharmacodynamics of the novel daily rivastigmine transdermal patch compared with twice-daily capsules in Alzheimer's disease patients

A transdermal patch has been developed for the cholinesterase inhibitor rivastigmine. This study investigated the pharmacokinetics and pharmacodynamics of rivastigmine and NAP226-90, and compared drug exposure between patch and capsule administrations. This was an open-label, parallel-group study in Alzheimer's disease patients randomized to receive either capsule (1.5-6 mg Q12H, i.e., 3-12 mg/day) or patch (5-20 cm2) in ascending doses through four 14-day periods. The patch showed lower Cmax (ca. 30% lower at 20 cm2, 19.5 versus 29.3 ng/ml), longer tmax (8.0 versus 1.0 h), and greater AUC (ca. 1.8-fold at 20 cm2, 345 versus 191 ng x h/ml) compared with the 6 mg Q12H capsule dose, with markedly less fluctuation between peak and trough plasma levels (80% at 20 cm2 versus 620% at 1.5 mg Q12H). Plasma butyrylcholinesterase inhibition rose slowly after patch administration, whereas two distinct peaks were seen after capsule administration. Average exposure with the 10 cm2 patch was comparable to the highest capsule dose (6 mg Q12H, i.e., 12 mg/day).

QT effects of duloxetine at supratherapeutic doses: a placebo and positive controlled study

BACKGROUND

The electrophysiological effects of duloxetine at supratherapeutic exposures were evaluated to ensure compliance with regulatory criteria and to assess the QT prolongation potential.

METHODS

Electrocardiograms were collected in a multicenter, double-blind, randomized, placebo-controlled, crossover study that enrolled 117 healthy female subjects aged 19 to 74 years. Duloxetine dosages escalated from 60 mg twice daily to 200 mg twice daily; a single moxifloxacin 400 mg dose was used as a positive control. Data were analyzed using 3 QT interval correction methods: mixed-effect analysis of covariance model with RR interval change from baseline as the covariate, the QT Fridericia's correction method, and the individual QT correction method. Concentrations of duloxetine and its 2 major metabolites were measured.

RESULTS

Compared with placebo, the mean change from baseline in QTc decreased with duloxetine 200 mg twice daily. The upper limits of the 2-sided 90% confidence intervals for duloxetine vs. placebo were <0 msec at each time point by any correction method. No subject had absolute QT Fridericia's correction values >445 msec with duloxetine, and the change in QT Fridericia's correction from baseline with duloxetine did not exceed 36 msec. No relationship was detected between QTc change and plasma concentrations of duloxetine or its metabolites even though average duloxetine concentrations ranged to more than 5 times those achieved at therapeutic doses. Moxifloxacin significantly prolonged QTc at all time points, regardless of correction method.

CONCLUSIONS

Duloxetine does not affect ventricular repolarization as assessed by both mean changes and outliers in QT corrected by any method.

Defining and assessing adherence to oral antipsychotics: a review of the literature

The definition and assessment of adherence vary considerably across studies. Increasing consensus regarding these issues is necessary to improve our understanding of adherence and the development of more effective treatments. We review the adherence literature over the past 3 decades to explore the definitions and assessment of adherence to oral antipsychotics in schizophrenia patients. A total of 161 articles were identified through MEDLINE and PsycINFO searches. The most common method used to assess adherence was the report of the patient. Subjective and indirect methods including self-report, provider report, significant other report, and chart review were the only methods used to assess adherence in over 77% (124/161) of studies reviewed. Direct or objective measures including pill count, blood or urine analysis, electronic monitoring, and electronic refill records were used in less than 23% (37/161) of studies. Even in studies utilizing the same methodology to assess adherence, definitions of an adherent subject varied broadly from agreeing to take any medication to taking at least 90% of medication as prescribed. We make suggestions for consensus development, including the use of recommended terminology for different subject samples, the increased use of objective or direct measures, and the inclusion in all studies of an estimate of the percentage of medication taken as prescribed in an effort to increase comparability among studies. The suggestions are designed to advance the field with respect to both understanding predictors of adherence and developing interventions to improve adherence to oral antipsychotic medications.

Pharmacokinetic profile and clinical efficacy of long-acting risperidone: potential benefits of combining an atypical antipsychotic and a new delivery system

Continuous long-term antipsychotic therapy is required for patients with schizophrenia to optimise treatment benefits. The use of long-acting antipsychotic preparations can help to ensure compliance with therapy and has been shown to improve efficacy in relapse prevention when compared with oral agents. How- ever, the use of long-acting agents has been limited, since this approach to patient care has only been available with conventional drugs. The atypical antipsychotic agents have provided a new option for the treatment of schizophrenia. However, entwined with health system limitations, partial or non-compliance remains a problem with oral atypical antipsychotic agents. Combining the attributes of the atypical antipsychotic class with the pharmacokinetic profile and compliance advantages of a long-acting formulation could potentially be an important advance in the management of patients requiring continuous anti- psychotic therapy. This review considers the available clinical data supporting possible advantages for the only long-acting atypical agent currently available, long-acting risperidone, as a microsphere formulation. The drug-delivery technology employed provides a sustained therapeutic plasma level, with administration once every 2 weeks, and this is translated into improved symptom control and improved quality of life, even in patients already deemed clinically stable on an oral agent or on a conventional depot antipsychotic.

Antidepressant Drug-Drug Interaction Profile Update

Drug-drug interactions continue to be underappreciated and misunderstood by most clinicians. Although life-threatening drug interactions are rare, serious clinical consequences, including altered drug response, poor tolerability with reduced medication adherence, and increased costs for care tied to the increased complexity of therapy, are fairly commonplace. Drug interactions may be further complicated by genetic differences in metabolic capacity. Patients who routinely require long-term treatment for depression have an increased likelihood of experiencing a drug-drug interaction since they will take over-the-counter and prescription medications for intercurrent and/or co-morbid illness. Antidepressants can be the object of drug interactions when their metabolic pathways are affected by other substances, or they can precipitate interactions by inhibiting enzyme pathways. Clinicians can improve the short- and long-term outcomes of patients with a depressive disorder by considering the possibility of drug-drug interactions both before prescribing a specific antidepressant and while monitoring for response, adverse effects and patient compliance.

The Texas Medication Algorithm Project antipsychotic algorithm for schizophrenia: 2003 update

BACKGROUND

The Texas Medication Algorithm Project (TMAP) has been a public-academic collaboration in which guidelines for medication treatment of schizophrenia, bipolar disorder, and major depressive disorder were used in selected public outpatient clinics in Texas. Subsequently, these algorithms were implemented throughout Texas and are being used in other states. Guidelines require updating when significant new evidence emerges; the antipsychotic algorithm for schizophrenia was last updated in 1999. This article reports the recommendations developed in 2002 and 2003 by a group of experts, clinicians, and administrators.

METHOD

A conference in January 2002 began the update process. Before the conference, experts in the pharmacologic treatment of schizophrenia, clinicians, and administrators reviewed literature topics and prepared presentations. Topics included ziprasidone's inclusion in the algorithm, the number of antipsychotics tried before clozapine, and the role of first generation antipsychotics. Data were rated according to Agency for Healthcare Research and Quality criteria. After discussing the presentations, conference attendees arrived at consensus recommendations. Consideration of aripiprazole's inclusion was subsequently handled by electronic communications.

RESULTS

The antipsychotic algorithm for schizophrenia was updated to include ziprasidone and aripiprazole among the first-line agents. Relative to the prior algorithm, the number of stages before clozapine was reduced. First generation antipsychotics were included but not as first-line choices. For patients refusing or not responding to clozapine and clozapine augmentation, preference was given to trying monotherapy with another antipsychotic before resorting to antipsychotic combinations.

CONCLUSION

Consensus on algorithm revisions was achieved, but only further well-controlled research will answer many key questions about sequence and type of medication treatments of schizophrenia.