Prophylactic Efficacy of Riluzole against Anxiety- and Depressive-Like Behaviors in Two Rodent Stress Models.

Introduction: Chronic stress-related illnesses such as major depressive disorder and post-traumatic stress disorder share symptomatology, including anxiety, anhedonia, and helplessness. Across disorders, neurotoxic dysregulated glutamate (Glu) signaling may underlie symptom emergence. Current first-line antidepressant drugs, which do not directly target Glu signaling, fail to provide adequate benefit for many patients and are associated with high relapse rates. Riluzole modulates glutamatergic neurotransmission by increasing metabolic cycling and modulating signal transduction. Clinical studies exploring riluzole's efficacy in stress-related disorders have provided varied results. However, the utility of riluzole for treating specific symptom dimensions or as a prophylactic treatment has not been comprehensively assessed. Methods: We investigated whether chronic prophylactic riluzole (∼12-15 mg/kg/day p.o.) could prevent the emergence of behavioral deficits induced by unpredictable chronic mild stress (UCMS) in mice. We assessed (i) anxiety-like behavior using the elevated-plus maze, open-field test, and novelty-suppressed feeding, (ii) mixed anxiety/anhedonia-like behavior in the novelty-induced hypophagia test, and (iii) anhedonia-like behavior using the sucrose consumption test. Z-scoring summarized changes across tests measuring similar dimensions. In a separate learned helplessness (LH) cohort, we investigated whether chronic prophylactic riluzole treatment could block the development of helplessness-like behavior. Results: UCMS induced an elevation in anhedonia-like behavior and overall behavioral emotionality that was blocked by prophylactic riluzole. In the LH cohort, prophylactic riluzole blocked the development of helplessness-like behavior. Discussion/Conclusion: This study supports the utility of riluzole as a prophylactic medication for preventing anhedonia and helplessness symptoms associated with stress-related disorders.

A phase Ib dose-escalation study of troriluzole (BHV-4157), an oral glutamatergic signaling modulator, in combination with nivolumab in patients with advanced solid tumors.

BACKGROUND: Glutamate signaling activates MAPK and PI3K/AKT pathways in tumor cells. Treatment with riluzole, a glutamate release inhibitor, has been previously shown to be safe in melanoma patients and produced biologic effects, but did not lead to radiographic responses, possibly due to poor pharmacokinetic properties. Therefore, we conducted a phase Ib trial to determine the safety and tolerability of the combination of the riluzole prodrug troriluzole (BHV-4157, trigriluzole) and the PD-1 antibody nivolumab in patients with advanced solid tumors. METHODS: Patients with advanced or refractory solid tumors and measurable disease per RECIST 1.1 were treated with increasing doses of troriluzole using a semi-Bayesian modified toxicity probability interval dose escalation procedure. Troriluzole monotherapy was orally self-administered for a 14-day lead-in period followed by continuation of troriluzole in combination with nivolumab 240 mg IV every 2 weeks. Endpoints included safety, pharmacokinetics (PK) and efficacy. RESULTS: We enrolled 14 patients with advanced solid tumors (melanoma = 3, NSCLC = 3, renal cell carcinoma = 2, bladder/urothelial = 2, ovarian cancer = 1, adenoid cystic carcinoma = 1, pleural mesothelial = 1, head and neck cancer = 1). Eleven patients had cancer progression on prior therapy with PD-1 or PD-L1 agent. Patients received troriluzole total daily doses from 140 to 560 mg (divided). The most common treatment-related adverse events (TRAE) occurring in ≥ 5 patients (> 35%) were transaminitis and increased lipase. DLT (dose-limiting toxicity) occurred in 3 patients: (1) grade 3 anorexia, (2) grade 3 fatigue and, (3) grade 3 atrial fibrillation. Six patients were treated at the MTD (maximum tolerated dose). No subjects discontinued treatment due to AEs. One response occurred (7%), which was a partial response in a subject who had PD-1 refractory disease. The 6-month PFS rate was 21%. PK data showed that the prodrug troriluzole was efficiently cleaved into riluzole by 2-h post-dosing in all dose cohorts tested. CONCLUSION: The combination of troriluzole and nivolumab was safe and well-tolerated. The MTD of troriluzole was determined to be 420 mg total daily dose. The observed antitumor activity, primarily disease stabilization, is of interest in patients with PD-1 resistant tumors. Trial Registration ClinicalTrials.gov Identifier NCT03229278.

Assessing Effects of BHV-0223 40 mg Zydis Sublingual Formulation and Riluzole 50 mg Oral Tablet on Liver Function Test Parameters Utilizing DILIsym.

For patients with amyotrophic lateral sclerosis who take oral riluzole tablets, approximately 50% experience alanine transaminase (ALT) levels above upper limit of normal (ULN), 8% above 3× ULN, and 2% above 5× ULN. BHV-0223 is a novel 40 mg rapidly sublingually disintegrating (Zydis) formulation of riluzole, bioequivalent to conventional riluzole 50 mg oral tablets, that averts the need for swallowing tablets and mitigates first-pass hepatic metabolism, thereby potentially reducing risk of liver toxicity. DILIsym is a validated multiscale computational model that supports evaluation of liver toxicity risks. DILIsym was used to compare the hepatotoxicity potential of oral riluzole tablets (50 mg BID) versus BHV-0223 (40 mg BID) by integrating clinical data and in vitro toxicity data. In a simulated population (SimPops), ALT levels > 3× ULN were predicted in 3.9% (11/285) versus 1.4% (4/285) of individuals with oral riluzole tablets and sublingual BHV-0223, respectively. This represents a relative risk reduction of 64% associated with BHV-0223 versus conventional riluzole tablets. Mechanistic investigations revealed that oxidative stress was responsible for the predicted ALT elevations. The validity of the DILIsym representation of riluzole and assumptions is supported by its ability to predict rates of ALT elevations for riluzole oral tablets comparable with that observed in clinical data. Combining a mechanistic, quantitative representation of hepatotoxicity with interindividual variability in both susceptibility and liver exposure suggests that sublingual BHV-0223 confers diminished rates of liver toxicity compared with oral tablets of riluzole, consistent with having a lower overall dose of riluzole and bypassing first-pass liver metabolism.

A Pharmacokinetic Bioequivalence Study Comparing Sublingual Riluzole (BHV-0223) and Oral Tablet Formulation of Riluzole in Healthy Volunteers.

Orally administered riluzole extends survival in patients with amyotrophic lateral sclerosis, although it has significant shortcomings (eg, adverse events, dysphagic patients) that limit its utility. BHV-0223 is a Zydis-based orally disintegrating formulation of riluzole designed for sublingual administration that addresses the limitations of conventional tablets. This study assessed the bioequivalence between 40-mg BHV-0223 and standard 50-mg oral riluzole tablets, and the food effect on BHV-0223 pharmacokinetics in healthy volunteers. Overall, 133 healthy subjects received BHV-0223 and riluzole tablets under fasted conditions. Geometric mean ratios for the area under the plasma concentration-time curve (AUC) from time zero to time of last nonzero concentration (AUC0-t ) (89.9%; confidence interval [CI], 87.3%-92.5%), AUC from time zero to infinity (AUC0-∞ ) (89.8%; CI, 87.3%-92.4%), and maximum observed concentration (112.7%; CI, 105.5%-120.4%) all met bioequivalence criteria (80%-125%). Subsequently, 67 subjects received BHV-0223 under fed conditions. The geometric mean ratios of AUC0-t (91.2%; CI, 88.1-94.3%), and AUC0-∞ (92.0%; CI, 89.0-95.1%) were similar, but maximum observed concentration ratios were not within bioequivalence criteria. BHV-0223 was well tolerated. This study demonstrated that 40-mg sublingual BHV-0223 is bioequivalent to 50-mg oral riluzole tablets.

The γ-Secretase Modulator, BMS-932481, Modulates Aß Peptides in the Plasma and Cerebrospinal Fluid of Healthy Volunteers.

The pharmacokinetics, pharmacodynamics, safety, and tolerability of BMS-932481, a γ-secretase modulator (GSM), were tested in healthy young and elderly volunteers after single and multiple doses. BMS-932481 was orally absorbed, showed dose proportionality after a single dose administration, and had approximately 3-fold accumulation after multiple dosing. High-fat/caloric meals doubled the Cmax and area under the curve and prolonged Tmax by 1.5 hours. Consistent with the preclinical pharmacology of GSMs, BMS-932481 decreased cerebrospinal fluid (CSF) Aß39, Aß40, and Aß42 while increasing Aß37 and Aß38, thereby providing evidence of γ-secretase enzyme modulation rather than inhibition. In plasma, reductions in Aß40 and Aß42 were observed with no change in total Aß; in CSF, modest decreases in total Aß were observed at higher dose levels. Increases in liver enzymes were observed at exposures associated with greater than 70% CSF Aß42 lowering after multiple dosing. Although further development was halted due to an insufficient safety margin to test the hypothesis for efficacy of Aß lowering in Alzheimer's disease, this study demonstrates that γ-secretase modulation is achievable in healthy human volunteers and supports further efforts to discover well tolerated GSMs for testing in Alzheimer's disease and other indications.

Targeting Prodromal Alzheimer Disease With Avagacestat: A Randomized Clinical Trial.

IMPORTANCE: Early identification of Alzheimer disease (AD) is important for clinical management and affords the opportunity to assess potential disease-modifying agents in clinical trials. To our knowledge, this is the first report of a randomized trial to prospectively enrich a study population with prodromal AD (PDAD) defined by cerebrospinal fluid (CSF) biomarker criteria and mild cognitive impairment (MCI) symptoms. OBJECTIVES: To assess the safety of the γ-secretase inhibitor avagacestat in PDAD and to determine whether CSF biomarkers can identify this patient population prior to clinical diagnosis of dementia. DESIGN, SETTING, AND PARTICIPANTS: A randomized, placebo-controlled phase 2 clinical trial with a parallel, untreated, nonrandomized observational cohort of CSF biomarker-negative participants was conducted May 26, 2009, to July 9, 2013, in a multicenter global population. Of 1358 outpatients screened, 263 met MCI and CSF biomarker criteria for randomization into the treatment phase. One hundred two observational cohort participants who met MCI criteria but were CSF biomarker-negative were observed during the same study period to evaluate biomarker assay sensitivity. INTERVENTIONS: Oral avagacestat or placebo daily. MAIN OUTCOMES AND MEASURE: Safety and tolerability of avagacestat. RESULTS: Of the 263 participants in the treatment phase, 132 were randomized to avagacestat and 131 to placebo; an additional 102 participants were observed in an untreated observational cohort. Avagacestat was relatively well tolerated with low discontinuation rates (19.6%) at a dose of 50 mg/d, whereas the dose of 125 mg/d had higher discontinuation rates (43%), primarily attributable to gastrointestinal tract adverse events. Increases in nonmelanoma skin cancer and nonprogressive, reversible renal tubule effects were observed with avagacestat. Serious adverse event rates were higher with avagacestat (49 participants [37.1%]) vs placebo (31 [23.7%]), attributable to the higher incidence of nonmelanoma skin cancer. At 2 years, progression to dementia was more frequent in the PDAD cohort (30.7%) vs the observational cohort (6.5%). Brain atrophy rate in PDAD participants was approximately double that of the observational cohort. Concordance between abnormal amyloid burden on positron emission tomography and pathologic CSF was approximately 87% (κ = 0.68; 95% CI, 0.48-0.87). No significant treatment differences were observed in the avagacestat vs placebo arm in key clinical outcome measures. CONCLUSIONS AND RELEVANCE: Avagacestat did not demonstrate efficacy and was associated with adverse dose-limiting effects. This PDAD population receiving avagacestat or placebo had higher rates of clinical progression to dementia and greater brain atrophy compared with CSF biomarker-negative participants. The CSF biomarkers and amyloid positron emission tomography imaging were correlated, suggesting that either modality could be used to confirm the presence of cerebral amyloidopathy and identify PDAD. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00890890.

Comparison of "Word" vs. "Picture" Version of the Free and Cued Selective Reminding Test (FCSRT) in Older Adults.

BACKGROUND: This study examined the psychometric relationship between the Word and Picture versions of the Free and Cued Selective Reminding Test (FCSRT) and developed an equation for score conversion. METHODS: 187 participants were administered the FCSRT-Picture and FCSRT-Word on two visits using a randomized counterbalanced design. RESULTS: Participants had a mean age of 82.1 (sd=5.4) and mean education of 14.5 (sd=3.3) years. Mean FCSRT-Picture Free Recall score (mean 33.0, range: 17-44) was 7.9 points higher than the Word score (mean 25.1, range: 3-43). The Picture and Word FCSRT correlations for Free Recall and Total Recall were r=0.56, p<0.01 and r=0.46, p<0.01, respectively. DISCUSSION: The Picture and Word versions of the FCSRT were moderately associated in a sample of cognitively normal older adults. The score mean differences and variability between FCSRT-Picture and FCSRT-Word indicate that their scores should not be considered equivalent.

Comparison of adjunctive use of aripiprazole with bupropion or selective serotonin reuptake inhibitors/serotonin-norepinephrine reuptake inhibitors: analysis of patients beginning adjunctive treatment in a 52-week, open-label study.

BACKGROUND: This post hoc analysis assessed the safety, tolerability and effectiveness of long-term treatment with aripiprazole adjunctive to either bupropion or selective serotonin reuptake inhibitors (SSRIs)/serotonin-norepinephrine reuptake inhibitors (SNRIs) in patients with major depressive disorder (MDD). METHODS: Data from de novo patients (did not participate in 2 previous studies) in a 52-week, open-label safety study of adjunctive aripiprazole after documented inadequate response to 1-4 antidepressant treatments (ADTs; SSRI, SNRI, or bupropion) were analyzed post hoc. Assessments included safety and tolerability, sexual functioning (Massachusetts General Hospital Sexual Functioning Inventory [MGH-SFI]) and Clinical Global Impressions-Severity (CGI-S). RESULTS: Forty-seven patients received bupropion plus aripiprazole and 245 received an SSRI/SNRI plus aripiprazole; 19 (40.4%) and 78 (31.8%), respectively, completed 52 weeks of treatment, and 46 and 242, respectively, received ≥1 dose of study medication (safety sample). Median time to discontinuation (any reason) was 184.0 days. Overall, 97.8% of patients in the bupropion group and 93.8% in the SSRI/SNRI group experienced ≥1 adverse event. The most common treatment-emergent adverse events were fatigue (26.1%) and somnolence (21.7%) with bupropion and fatigue (23.6%) and akathisia (23.6%) with an SSRI/SNRI. Mean change in body weight at week 52 (observed cases) was +3.1 kg for bupropion and +2.4 kg for an SSRI/SNRI. Treatment-emergent, potentially clinically relevant abnormalities in fasting glucose occurred in 8.3% of patients with bupropion and 17.4% with an SSRI/SNRI; for abnormalities in fasting total cholesterol, the incidence was 25.0% and 34.7%, respectively. Mean (SE) change from baseline in fasting glucose was 1.4 (1.9) mg/dL with bupropion and 2.7 (1.5) mg/dL with an SSRI/SNRI. Baseline MGH-SFI item scores indicated less severe impairment with bupropion versus an SSRI/SNRI; in both groups most MGH-SFI items exhibited improvement at week 52. Mean CGI-S improvement at week 52 (last observation carried forward) was -1.4 with bupropion and -1.5 with an SSRI/SNRI (efficacy sample). CONCLUSIONS: There were no unexpected AEs with long-term adjunctive aripiprazole therapy when added to either bupropion or SSRIs/SNRIs, and symptom improvement was similar between ADT groups. Sexual functioning in patients with MDD on antidepressants was also modestly improved after adding aripiprazole. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00095745 (November 9, 2004).

Effect of symptom severity on efficacy and safety of aripiprazole adjunctive to antidepressant monotherapy in major depressive disorder: a pooled analysis.

BACKGROUND: There is a paucity of evidence for outcome predictors in patients with major depressive disorder (MDD) not responding to initial antidepressant therapy (ADT). This post-hoc analysis evaluated whether MDD severity affects response to adjunctive aripiprazole. METHODS: Data from 3 randomized, double-blind, placebo-controlled trials of adjunctive aripiprazole in adults with MDD and inadequate response to 1 to 3 ADT trials were pooled and stratified based on Montgomery-Åsberg Depression Rating Scale (MADRS) total score (mild, ≤24; moderate, 25-30; severe, ≥31). Treatment differences in change in MADRS total score and rates of response (≥50% MADRS improvement) and remission (response with MADRS total score ≤10) were analyzed at endpoint. Adverse events were assessed within each subgroup. RESULTS: Aripiprazole produced greater improvement than placebo in the MADRS total score regardless of MDD severity at baseline (between-treatment difference [95% CI]: mild, -2.5 [-4.0 to -1.1]; moderate, -3.2 [-4.9 to -1.6]; severe, -4.5 [-6.8 to -2.2]). Compared with placebo, adjunctive aripiprazole increased the likelihood of response in all subgroups (risk ratio [95% CI]: mild, 1.50 [1.15, 1.95]; moderate, 1.51 [1.09, 2.11]; severe, 1.95 [1.23, 3.10]). Common treatment-emergent adverse events included akathisia and restlessness. LIMITATIONS: The original studies were not designed to assess the efficacy of adjunctive aripiprazole by baseline severity, and this post-hoc analysis was not powered to evaluate differences in severity subgroups. CONCLUSIONS: In patients who failed to respond to initial ADT, adjunctive aripiprazole was more effective than placebo in mild, moderate, and severe MDD strata. CLINICAL TRIAL REGISTRATION: ClinicalTrial.gov: NCT00095823, NCT00105196, and NCT00095758.

Efficacy of adjunctive aripiprazole in patients with major depressive disorder whose symptoms worsened with antidepressant monotherapy.

INTRODUCTION: Efficacy of depression treatments, including adjunctive antipsychotic treatment, has not been explored for patients with worsening symptoms after antidepressant therapy (ADT). METHODS: This post-hoc analysis utilized pooled data from 3 similarly designed, randomized, double-blind, placebo-controlled trials that assessed the efficacy, safety, and tolerability of adjunctive aripiprazole in patients with major depressive disorder with inadequate response to ADT. The studies had 2 phases: an 8-week prospective ADT phase and 6-week adjunctive (aripiprazole or placebo) treatment phase. This analysis focused on patients whose symptoms worsened during the prospective 8-week ADT phase (worsening defined as >0% increase in Montgomery-Åsberg Depressive Rating Scale [MADRS] Total score). During the 6-week, double-blind, adjunctive phase, response was defined as ≥50% reduction in MADRS Total score and remission as ≥50% reduction in MADRS Total score and MADRS score ≤10. RESULTS: Of 1065 patients who failed to achieve a response during the prospective phase, 160 exhibited worsening of symptoms (ADT-Worseners), and 905 exhibited no change/reduction in MADRS scores (ADT-Non-worseners). Response rates for ADT-Worseners at endpoint were 36.6% (adjunctive aripiprazole) and 22.5% (placebo). Similarly, response rates at endpoint for ADT-Non-worseners were 37.5% (adjunctive aripiprazole) and 22.5% (placebo). Remission rates at endpoint for ADT-Worseners were 25.4% (adjunctive aripiprazole) and 12.4% (placebo). For ADT-Non-worseners, remission rates were 29.9% (adjunctive aripiprazole) and 17.4% (placebo). CONCLUSION: These results suggest that adjunctive aripiprazole is an effective intervention for patients whose symptoms worsen during antidepressant monotherapy. The results challenge the view that benefits of adjunctive therapy with aripiprazole are limited to partial responders to ADT.

Screening for predementia AD: time-dependent operating characteristics of episodic memory tests.

OBJECTIVE: Data from the Einstein Aging Study (EAS) were used to prospectively evaluate the free recall score from the free and cued selective reminding test (FCSRT-FR) and logical memory I immediate recall (LM-IR) subtest of the Wechsler memory scale-revised for prediction of incident Alzheimer disease (AD) dementia among individuals from a community-based cohort with memory complaints. METHODS: Analyses included 854 participants, age ≥70 years, who initially had no dementia, and had memory complaints. Clinic evaluations were completed annually and AD dementia was diagnosed using standard criteria (n = 86 cases; average follow-up 4.1 years). Time-dependent receiver operating characteristic analysis was used to evaluate the prognostic ability of FCSRT-FR and LM-IR for incident AD over various durations of follow-up. RESULTS: For identifying those with memory complaints who will develop incident AD dementia over 2-4 years, the FCSRT-FR had better operating characteristics than LM-IR. APOE ε4 status, age, and education did not affect cut points; however, positive predictive values were higher among APOE ε4-positive individuals. CONCLUSIONS: For follow-up intervals of 2-4 years, the FCSRT-FR is more predictive than the LM-IR for identifying individuals with memory complaints who will develop incident AD. APOE ε4 status improves positive predictive value, but does not affect the choice of optimal cuts.

Pharmacodynamics of selective inhibition of γ-secretase by avagacestat.

A hallmark of Alzheimer's disease (AD) pathology is the accumulation of brain amyloid ß-peptide (Aß), generated by γ-secretase-mediated cleavage of the amyloid precursor protein (APP). Therefore, γ-secretase inhibitors (GSIs) may lower brain Aß and offer a potential new approach to treat AD. As γ-secretase also cleaves Notch proteins, GSIs can have undesirable effects due to interference with Notch signaling. Avagacestat (BMS-708163) is a GSI developed for selective inhibition of APP over Notch cleavage. Avagacestat inhibition of APP and Notch cleavage was evaluated in cell culture by measuring levels of Aß and human Notch proteins. In rats, dogs, and humans, selectivity was evaluated by measuring plasma blood concentrations in relation to effects on cerebrospinal fluid (CSF) Aß levels and Notch-related toxicities. Measurements of Notch-related toxicity included goblet cell metaplasia in the gut, marginal-zone depletion in the spleen, reductions in B cells, and changes in expression of the Notch-regulated hairy and enhancer of split homolog-1 from blood cells. In rats and dogs, acute administration of avagacestat robustly reduced CSF Aß40 and Aß42 levels similarly. Chronic administration in rats and dogs, and 28-day, single- and multiple-ascending-dose administration in healthy human subjects caused similar exposure-dependent reductions in CSF Aß40. Consistent with the 137-fold selectivity measured in cell culture, we identified doses of avagacestat that reduce CSF Aß levels without causing Notch-related toxicities. Our results demonstrate the selectivity of avagacestat for APP over Notch cleavage, supporting further evaluation of avagacestat for AD therapy.

Improving Alzheimer's disease phase II clinical trials.

Over the past 30 years, many drugs have been studied as possible treatments for Alzheimer's disease, but only four have demonstrated sufficient efficacy to be approved as treatments, of which three are in the same class. This lack of success has raised questions both in the pharmaceutical industry and academia about the future of Alzheimer's disease therapy. The high cost and low success rate of drug development across many disease areas can be attributed, in large part, to late-stage clinical failures (Schachter and Ramoni, Nat Rev Drug Discov 2007;6:107-8). Thus, identifying in phase II, or preferably phase I, drugs that are likely to fail would have a dramatic impact on the costs associated with developing new drugs. With this in mind, the Alzheimer's Association convened a Research Roundtable on June 23 and 24, 2011, in Washington, DC, bringing together scientists from academia, industry, and government regulatory agencies to discuss strategies for improving the probability of phase II trial results predicting success when considering the go/no-go decision-making process leading to the initiation of phase III.

A contrast in safety, pharmacokinetics and pharmacodynamics across age groups after a single 50 mg oral dose of the γ-secretase inhibitor avagacestat.

AIM: To evaluate the single dose pharmacokinetics, pharmacodynamics, and preliminary tolerability of the γ-secretase inhibitor BMS-708163 (avagacestat) in young and elderly men and women. METHODS: All subjects received double-blinded administration of a single 50 mg dose of avagacestat in capsule form or matching placebo. Main evaluations included pharmacokinetics, safety, plasma amyloid-ß (Aß)(1-40) concentratios and exploration of Notch biomarkers. RESULTS: Avagacestat 50 mg capsule was well tolerated and rapidly absorbed among young and elderly subjects, with a median t(max) between 1 and 2 h post dose and an average half-life between 41 and 71 h. In general, subjects aged 75 years or more had higher AUC(0,∞) values than those aged less than 75 years. An exploratory analysis of Aß(1-40) serum concentrations showed a pattern of decreasing concentrations over the first 4-6 h followed by a rise above baseline that was maintained until the end of the assessment period. Adverse events were generally mild, occurring more frequently in elderly subjects, with no observed difference between subjects receiving avagacestat and placebo. No dose limiting gastrointestinal effects of avagacestat were observed and exploratory biomarkers of Notch inhibition did not change significantly. CONCLUSIONS: The favourable safety profile and pharmacokinetic effects of avagacestat in this study support its continued development, especially in the target population of elderly subjects with mild cognitive impairment or Alzheimer's disease.

Effects of single doses of avagacestat (BMS-708163) on cerebrospinal fluid Aß levels in healthy young men.

BACKGROUND: The concentration of amyloid ß (Aß) peptides in cerebrospinal fluid (CSF) is a biomarker for Alzheimer's disease (AD) pathology, and has been used to evaluate the effectiveness of γ-secretase inhibition. Avagacestat is a selective γ-secretase inhibitor in development for the treatment of AD. The primary objective of this study was to assess the effects of single oral doses of avagacestat on the CSF Aß concentrations in healthy male subjects. Secondary objectives included single-dose pharmacokinetics in CSF and plasma, safety and tolerability. METHODS: This was a double-blind, placebo-controlled, randomized, single-dose study. Healthy male subjects were assigned to one of three sequential avagacestat dose panels (50, 200 and 400 mg) or placebo as single oral doses. RESULTS: 34 subjects were enrolled. Administration of a single dose of 200 or 400 mg of avagacestat resulted in a marked decrease in CSF Aß(1-38), Aß(1-40) and Aß(1-42) concentrations vs placebo; with smaller decreases observed in the 50 mg dose group. Avagacestat was quickly absorbed into the systemic circulation, with a mean time to reach maximum plasma concentration (t(max)) of approximately 1-2 h, and a CSF t(max) of approximately 3 h. Adverse events were uncommon and occurred with similar frequency in the placebo and avagacestat groups. CONCLUSION: Avagacestat was safe, well tolerated, and resulted in a notable decrease in CSF Aß concentrations, suggestive of γ-secretase inhibition. The results warrant further clinical study in patients with AD.

A placebo-controlled, multiple ascending dose study to evaluate the safety, pharmacokinetics and pharmacodynamics of avagacestat (BMS-708163) in healthy young and elderly subjects.

BACKGROUND AND OBJECTIVES: Avagacestat is an orally active γ-secretase inhibitor that selectively inhibits amyloid ß (Aß) synthesis in cell culture and animal models. The objective of the current study was to assess the pharmacokinetics, pharmacodynamics, safety and tolerability of multiple doses of avagacestat over 28 days in healthy young men and elderly men and women in a placebo-controlled, sequential-panel, ascending multiple-dose study. METHODS: Thirty-three young men were assigned to four serial dose groups of avagacestat 15, 50, 100 or 150 mg (n = 6-7 per dose), or placebo (n = 2 per dose panel; 8 subjects total) once daily for 28 days. Elderly men and women were assigned to serial dose groups of avagacestat 50 mg and then 100 mg (n = 7 men, 6 women) or placebo (n = 2 men, 2 women) once daily for 14 days per dose level. RESULTS: Avagacestat was rapidly absorbed, had a terminal elimination half-life of 38-65 h, and reached a steady-state concentration by day 10 of daily dosing. Exposure in young subjects increased in proportion to dose. There were no apparent differences in steady-state area under the plasma concentration-time curve between young and elderly subjects; however, elderly subjects demonstrated a higher maximum plasma concentration for avagacestat. Doses of avagacestat >50 mg/day reduced steady-state trough concentrations of CSF Aß(1-38), Aß(1-40) and Aß(1-42) in a dose-dependent fashion over 28 days of daily dosing. There were no signs of potential Notch-related dose-limiting toxicities. CONCLUSION: The results support continued evaluation of avagacestat in an elderly target population with predementia and mild to moderate Alzheimer's disease.

Safety and tolerability of the γ-secretase inhibitor avagacestat in a phase 2 study of mild to moderate Alzheimer disease.

OBJECTIVE: To assess the safety, tolerability, and pharmacokinetic and pharmacodynamic effects of the -secretase inhibitor avagacestat in patients with mild to moderate Alzheimer disease (AD). DESIGN: Randomized, double-blind, placebo-controlled,24-week phase 2 study. SETTING: Global, multicenter trial. PATIENTS: A total of 209 outpatients with mild to moderate AD were randomized into the double-blind treatment phase. The median age of the patients was 75 years,58.9% were APOE ε4 carriers, and baseline measures of disease severity were similar among groups. INTERVENTION: Avagacestat, 25, 50, 100, or 125 mg daily,or placebo administered orally daily. MAIN OUTCOME MEASURES: Safety and tolerability of avagacestat. RESULTS: Discontinuation rates for the 25-mg and 50-mg doses of avagacestat were comparable with placebo but were higher in the 100-mg and 125-mg dose groups.Trends for worsening cognition, as measured by change from baseline Alzheimer Disease Assessment Scale cognitive subscale score, were observed in the 100-mg and125-mg dose groups. Treatment-emergent serious adverse events were similar across placebo and treatment groups. The most common reason for discontinuation was adverse events, predominantly gastrointestinal anddermatologic. Other adverse events occurring more frequentlyin patients undergoing treatment included reversibleglycosuria (without associated serum glucose changes), nonmelanoma skin cancer, and asymptomaticmagnetic resonance imaging findings. Exploratory cerebrospinal fluid amyloid isoforms and tau biomarker analysis demonstrated dose-dependent but not statistically significant reductions in a small subset of patients. CONCLUSIONS: Avagacestat dosed at 25 and 50 mg daily was relatively well tolerated and had low discontinuation rates. The 100-mg and 125-mg dose arms were poorly tolerated with trends for cognitive worsening. Exploratory cerebrospinal fluid biomarker substudies provide preliminary support for -secretase target engagement,but additional studies are warranted to better characterize pharmacodynamic effects at the 25- and 50-mg doses.This study establishes an acceptable safety and tolerability dose range for future avagacestat studies in AD. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00810147

Efficacy of adjunctive aripiprazole in patients with major depressive disorder who showed minimal response to initial antidepressant therapy.

To evaluate the efficacy of adjunctive aripiprazole in patients with minimal response to prior antidepressant therapy (ADT). Pooled data from three randomized, double-blind, placebo-controlled studies assessing the efficacy of adjunctive aripiprazole to ADT in patients with major depressive disorder who had a minimal response [< 25% reduction on the Montgomery-Åsberg Depression Rating Scale (MADRS)] to an 8-week prospective ADT. During the 6-week, double-blind adjunctive phase, response was defined as at least 50% reduction in the MADRS score and remission as at least 50% reduction in MADRS score and a MADRS score ≤ 10. Rates were examined using analysis of covariance and Cochran-Mantel-Haenszel tests. Kaplan-Meier curves were used to calculate time to response and remission. Of 1038 patients, 72% (n=746) exhibited a minimal response to ADT (ADT minimal responder). Time to response and remission were significantly shorter for ADT minimal responders receiving aripiprazole+ADT versus adjunctive placebo+ADT. ADT minimal responders on aripiprazole+ADT showed significantly greater improvements in MADRS score at endpoint compared with minimal responders on placebo+ADT (-10.3 vs. -6.5, P<0.0001). In addition, ADT minimal responders exhibited significantly higher response rates with aripiprazole+ADT than placebo+ADT (36 vs. 19%, respectively, P<0.0001) and higher remission rates (24 vs. 12%, respectively, P<0.0001). The numbers needed to treat with aripiprazole+ADT were six for response and eight for remission. Aripiprazole augmentation had a rapid and clinically meaningful effect in ADT minimal responders.

Multicenter, randomized, double-blind, placebo-controlled, single-ascending dose study of the oral γ-secretase inhibitor BMS-708163 (Avagacestat): tolerability profile, pharmacokinetic parameters, and pharmacodynamic markers.

BACKGROUND: γ-Secretase inhibitors (GSIs) are being investigated for their potential to modify the progression of Alzheimer disease based on their ability to regulate amyloid-ß (Aß) accumulation. BMS-708163 (avagacestat) is an oral GSI designed for selective inhibition of Aß synthesis currently in development for the treatment of mild to moderate and predementia AD. In addition to the desired effect on Aß synthesis, GSIs affect Notch processing, which is thought to mediate some toxic adverse effects reported with this drug class. Avagacestat produced up to 190-fold greater selectivity for Aß synthesis than Notch processing in preclinical studies and may therefore produce less toxic adverse events than other less selective compounds. Presented here are the results of the first in-human study for this new GSI compound. OBJECTIVE: The goal of this study was to assess the tolerability profile, pharmacokinetic properties, and effects on pharmacodynamic markers (Aß, trefoil factor family 3 protein, dual specificity phosphatase 6, and hairy and enhancer of split-1) of single, oral doses of avagacestat in healthy, young, male volunteers. METHODS: This was a multicenter, randomized, double-blind, placebo-controlled, single-ascending dose study in 8 healthy young men (age, 18-45 years) per dosing panel. Each study participant was randomized to receive a single dose of placebo (n = 2) or avagacestat (n = 6 for each dose) as an oral solution in 1 of 9 sequential dose panels (0.3, 1.5, 5, 15, 50, 100, 200, 400, and 800 mg). For determination of avagacestat, blood samples were obtained before dosing and for up to 144 hours after dosing. For participants in the 800-mg avagacestat dose panel, additional samples were obtained at 216, 312, and 648 hours. For 40-amino acid isoform of Aß (Aß(1-40)) assessment, plasma samples were collected before avagacestat administration and up to 72 hours after dosing. RESULTS: Avagacestat concentrations peaked quickly after oral administration and then had a biphasic decrease in concentrations with a prolonged terminal phase. Exposures were proportional with doses up to 200 mg. Avagacestat was well tolerated at single oral doses up to 800 mg, with a biphasic effect on plasma Aß(1-40). Adverse events were predominately mild to moderate in severity with no evidence of dose dependence up to 200 mg. CONCLUSIONS: Results from this single-ascending dose study suggest that avagacestat was tolerated at a single-dose range of 0.3 to 800 mg and suitable for further clinical development.

Beneficial effects of adjunctive aripiprazole in major depressive disorder are not dependent on antidepressant therapy history: a post hoc analysis of 3 randomized, double-blind, placebo-controlled trials.

OBJECTIVE: To determine whether switching within or between antidepressant therapy (ADT) classes prior to the use of adjunctive antipsychotic treatment is associated with different outcomes in major depressive disorder (MDD). METHOD: This was a post hoc analysis of pooled data from 3 similar, multicenter, randomized, double-blind, placebo-controlled registrational studies of aripiprazole adjunctive to ADT conducted between September 2004 and April 2008. The trials comprised the following 3 phases: a 7- to 28-day screening phase, an 8-week single-blind prospective treatment phase, and a 6-week double-blind, randomized phase. Patients were aged 18-65 years and met DSM-IV-TR criteria for MDD. Patients with an inadequate response to ADT during the screening phase entered the prospective treatment phase, during which they were switched to another ADT medication of either the same or a different class. Those patients with an inadequate response were then randomized to double-blind adjunctive aripiprazole or adjunctive placebo and followed for 6 weeks. RESULTS: Mean improvement in Montgomery-Asberg Depression Rating Scale total score was significantly greater with adjunctive aripiprazole versus adjunctive placebo for both between-class (-9.2 vs -6.2, P < .001) and within-class (-9.8 vs -6.6, P < .001) switch groups. Relative risks for response were 1.6 (95% CI = 1.3-2.1) for those who switched between classes and 1.7 (95% CI = 1.2-2.2) for those who switched within class. CONCLUSIONS: Augmentation with aripiprazole, after either a between-class or within-class switch following initial ADT failure, is an effective option for patients with nonresponsive MDD. In contrast to current strategies employed in clinical practice, these results suggest that adjunctive aripiprazole is a logical strategy in patients unresponsive to ADT. TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT00105196, NCT00095758, NCT00095823.