Multiple-dose ponezumab for mild-to-moderate Alzheimer's disease: Safety and efficacy.

INTRODUCTION: Multiple intravenous doses of ponezumab, an anti-amyloid antibody, were evaluated in subjects with mild-to-moderate Alzheimer's disease (AD). METHODS: In part A, 77 subjects were randomized to ponezumab 0.1, 0.5, or 1 mg/kg (75 treated) and 26 to placebo (24 treated). In part B, 63 subjects were randomized and treated with ponezumab 3 or 8.5 mg/kg and 32 with placebo. Subjects received 10 infusions over 18 months and were followed for 6 months thereafter. RESULTS: Ponezumab was generally safe and well tolerated. Most common adverse events were fall (16.7% ponezumab, 21.4% placebo), headache (13.8%, 21.4%), and cerebral microhemorrhage (13.8%, 19.6%). Plasma ponezumab increased dose-dependently with limited accumulation. Cerebrospinal fluid penetration was low. Plasma Aß1-x and Aß1-40 showed robust increases, but cerebrospinal fluid biomarkers showed no dose response. Ponezumab had no effects on cognitive/functional outcomes or brain volume. CONCLUSIONS: Multiple-dose ponezumab was generally safe, but not efficacious, in mild-to-moderate AD.

Ponezumab in mild-to-moderate Alzheimer's disease: Randomized phase II PET-PIB study.

INTRODUCTION: The safety, pharmacokinetics, and effect on peripheral and central amyloid ß (Aß) of multiple doses of ponezumab, an anti-Aß monoclonal antibody, were characterized in subjects with mild-to-moderate Alzheimer's disease treated for 1 year. METHODS: Subjects were aged ≥50 years with Mini-Mental State Examination scores 16 to 26. Cohort Q was randomized to ponezumab 10 mg/kg (n = 12) or placebo (n = 6) quarterly. Cohort M was randomized to a loading dose of ponezumab 10 mg/kg or placebo, followed by monthly ponezumab 7.5 mg/kg (n = 12) or placebo (n = 6), respectively. RESULTS: Ponezumab was generally well tolerated. Plasma concentrations increased dose dependently, but cerebrospinal fluid (CSF) penetration was low. Plasma Aß increased dose dependently with ponezumab, but CSF biomarkers, brain amyloid burden, cognition, and function were not affected. CONCLUSIONS: Both ponezumab dosing schedules were generally safe and well tolerated but did not alter CSF biomarkers, brain amyloid burden, or clinical outcomes.

Burden of illness in fibromyalgia patients with comorbid depression.

OBJECTIVES: To assess the burden of fibromyalgia (FM) in patients with FM taking antidepressant medication for comorbid depression. METHODS: Symptom burden, impact on work and activity, and healthcare resource utilisation (HCRU) was examined at randomisation in patients enrolled in a clinical trial. Symptom burden was estimated based on self-reported health status measures. The Work Productivity and Activity Impairment: Specific Health Problem scale adapted to FM and a separate HCRU questionnaire were completed. The relationship between FM severity and burden was evaluated. RESULTS: The total population analysed comprised 193 patients; 71 (36.8%) had moderate FM and 119 (61.7%) severe FM. Patients had moderate pain, severe impairment in functioning due to FM, sleep disruption, mild anxiety, and mild depression. In the 7 days preceding randomisation, an average of 58.0% overall work impairment was reported, with 15.2% of working hours missed and 54.0% productivity while at work. In the 3 months preceding randomisation, on average, 5.0 visits per patient were made to healthcare professionals. Physical treatments were used by 34.7% and supplements by 31.6% of patients. Prescription and non-prescription medications, as well as professional services providing help with activities of daily living (ADL) that are impacted by FM, were used by >75% of patients. In addition, 50.4 hours of unpaid help was provided for ADL assistance. Total out-of-pocket expenditures were US$307.1, €410.4, or C$211.3, depending on location. FM burden worsened with increasing FM severity. CONCLUSIONS: This study demonstrates the significant burden of FM in patients with comorbid depression treated with an antidepressant.

Safety and pharmacology of ponezumab (PF-04360365) after a single 10-minute intravenous infusion in subjects with mild to moderate Alzheimer disease.

OBJECTIVE: Ponezumab (PF-04360365) is a humanized anti-amyloid beta (Aß) monoclonal antibody designed for treatment of Alzheimer disease (AD). A single 2-hour intravenous infusion of 0.1 to 10 mg/kg was previously shown to be safe and well tolerated in subjects with mild to moderate AD, with measurable effects on plasma and cerebrospinal fluid Aß. This phase I, dose-escalation, open-label study evaluated the safety, pharmacokinetics, and pharmacodynamics of a single 10-minute intravenous infusion. METHODS: Subjects with mild to moderate AD received ponezumab 1 mg/kg (n = 3), 3 mg/kg (n = 3), 5 mg/kg (n = 4), or 10 mg/kg (n = 5). They were followed up as outpatients for 6 months. RESULTS: All subjects completed the trial. Ponezumab was safe and well tolerated with no deaths, withdrawals, or drug-related moderate, severe, or serious adverse events. Mild drug-related adverse events included headache (3 patients) and lethargy and hypoesthesia (both in 1 patient). No infusion reactions, clinically meaningful laboratory abnormalities, vital sign changes, electrocardiographic changes, or antidrug antibodies were detected. There was no evidence of brain microhemorrhage, vasogenic edema, encephalitis, or other imaging abnormality. Cognitive function showed no treatment-related trends. Ponezumab displayed approximately dose-proportional increases in plasma exposure. Steady-state volume of distribution was 113 to 172 mL/kg, clearance was 2.7 to 3.0 mL/d/kg, and terminal half-life was 35 to 52 days. Plasma maximum observed concentration and the area under the plasma concentration-time profile from time 0 extrapolated to infinite time of Aß(1-x) and Aß(1-40) increased dose-dependently. CONCLUSIONS: Administration of ponezumab as a 10-minute infusion was safe and well tolerated and produced effects on plasma Aß species comparable with a 2-hour infusion. Shorter infusions may provide more flexibility, comfort, and convenience for patients and caregivers.

Safety and pharmacology of a single intravenous dose of ponezumab in subjects with mild-to-moderate Alzheimer disease: a phase I, randomized, placebo-controlled, double-blind, dose-escalation study.

OBJECTIVES: Ponezumab is a humanized antiamyloid beta (Aß) monoclonal antibody designed to treat Alzheimer disease (AD). METHODS: This randomized, double-blind, single-dose-escalation study evaluated the safety, pharmacokinetics, and pharmacodynamics of 0.1, 0.3, 1, 3, and 10 mg/kg ponezumab (n = 4, 4, 4, 6, and 8, respectively) versus placebo (n = 11) after a 2-hour intravenous infusion in subjects with mild-to-moderate AD. Cerebrospinal fluid (CSF) samples were obtained from the 1- and 10-mg/kg groups at baseline and at day 29. The subjects were followed for 1 year. RESULTS: All subjects completed the trial. Ponezumab was well tolerated with no drug-attributed serious adverse events. The most common adverse events were upper respiratory tract infection, headache, and back pain, all mild to moderate. One subject (10 mg/kg) experienced a mild hypersensitivity reaction. Another subject (0.1 mg/kg) demonstrated slight enlargement of a preexisting midbrain lesion. Electrocardiography and laboratory values (including CSF) were unremarkable. No evidence of new microhemorrhage, vasogenic edema, or meningoencephalitis was noted. Plasma maximum observed concentration increased approximately dose proportionally, and the area under the plasma concentration-time profile from time zero extrapolated to infinite time (AUC(inf)) increased slightly more than dose proportionally. Mean terminal half-life was approximately 6 weeks. Two subjects (10 mg/kg) had measurable CSF ponezumab concentrations (~0.5% of plasma values) at day 29. Plasma Aß(1-x) and Aß(1-40) increased dose dependently, and mean CSF Aß(1-x) increased 38% from baseline with 10 mg/kg (P = 0.002 vs placebo). CONCLUSIONS: A 2-hour infusion of 0.1 to 10 mg/kg ponezumab was well tolerated in subjects with mild-to-moderate AD. Plasma pharmacokinetic profile was approximately linear. Plasma Aß increased with dose, and CSF Aß increased at the highest dose, suggesting that intravenous ponezumab alters central Aß levels.

Evaluation of structural models to describe the effect of placebo upon the time course of major depressive disorder.

Major depressive disorder (MDD) is the leading cause of disability in many countries. Designing and evaluating clinical trials of antidepressants is difficult due to the pronounced and variable placebo response which is poorly defined and may be affected by trial design. Approximately half of recent clinical trials of commonly used antidepressants failed to show statistical superiority for the drug over placebo, which is partly attributable to a marked placebo response. These failures suggest the need for new tools to evaluate placebo response and drug effect in depression, as well as to help design more informative clinical trials. Disease progression modeling is a tool that has been employed for such evaluations and several models have been proposed to describe MDD. Placebo data from three clinical depression trials were used to evaluate three published models: the inverse Bateman (IBM), indirect response (IDR) and transit (TM) models. Each model was used to describe Hamilton Rating Scale for major depression (HAMD) data and results were evaluated. The IBM model had several deficiencies, making it unsuitable. The IDR and TM models performed well on most evaluations and appear suitable. Comparing the IDR and TM models showed less clear distinctions, although overall the TM was found to be somewhat better than the IDR model. Model based evaluation can provide a useful tool for evaluating the time course of MDD and detecting drug effect. However, the models used should be robust, with well estimated parameters.

An innovative design to establish proof of concept of the antidepressant effects of the NR2B subunit selective N-methyl-D-aspartate antagonist, CP-101,606, in patients with treatment-refractory major depressive disorder.

This randomized, placebo-controlled, double-blind study was the first to evaluate the antidepressant efficacy, safety, and tolerability of an NR2B subunit-selective N-methyl-D-aspartate receptor antagonist, CP-101,606. Subjects had major depression, according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria and a history of treatment refractoriness to least 1 adequate trial of a selective serotonin reuptake inhibitor. The study had 2 treatment periods. In period 1, subjects first received a 6-week open-label trial of paroxetine and a single-blind, intravenous placebo infusion. Period 1 nonresponders (n = 30) then received a randomized double-blind single infusion of CP-101,606 or placebo plus continued treatment with paroxetine for up to an additional 4 weeks (period 2). Depression severity was assessed using the Montgomery-Asberg Depression Rating Scale and 17-item Hamilton Depression Rating Scale. On the prespecified main outcome measure (change from baseline in the Montgomery-Asberg Depression Rating Scale total score at day 5 of period 2), CP-101,606 produced a greater decrease than did placebo (mean difference, 8.6; 80% confidence interval, -12.3 to -4.5) (P < 0.10). Hamilton Depression Rating Scale response rate was 60% for CP-101,606 versus 20% for placebo. Seventy-eight percent of CP-101,606-treated responders maintained response status for at least 1 week after the infusion. CP-101,606 was safe, generally well tolerated, and capable of producing an antidepressant response without also producing a dissociative reaction. Antagonism of the NR2B subtype of the N-methyl-D-aspartate receptor may be a fruitful target for the development of a new antidepressant with more robust effects and a faster onset compared with those currently available and capable of working when existing antidepressants do not.

Effects of a NR2B selective NMDA glutamate antagonist, CP-101,606, on dyskinesia and Parkinsonism.

Glutamate antagonists decrease dyskinesia and augment the antiparkinsonian effects of levodopa in animal models of Parkinson's disease (PD). In a randomized, double-blind, placebo-controlled clinical trial, we investigated the acute effects of placebo and two doses of a NR2B subunit selective NMDA glutamate antagonist, CP-101,606, on the response to 2-hour levodopa infusions in 12 PD subjects with motor fluctuations and dyskinesia. Both doses of CP-101,606 reduced the maximum severity of levodopa-induced dyskinesia approximately 30% but neither dose improved Parkinsonism. CP-101,606 was associated with a dose-related dissociation and amnesia. These results support the hypothesis that glutamate antagonists may be useful antidyskinetic agents. However, future studies will have to determine if the benefits of dyskinesia suppression can be achieved without adverse cognitive effects.

Noscapine crosses the blood-brain barrier and inhibits glioblastoma growth.

The opium alkaloid noscapine is a commonly used antitussive agent available in Europe, Asia, and South America. Although the mechanism by which it suppresses coughing is currently unknown, it is presumed to involve the central nervous system. In addition to its antitussive action, noscapine also binds to tubulin and alters microtubule dynamics in vitro and in vivo. In this study, we show that noscapine inhibits the proliferation of rat C6 glioma cells in vitro (IC(50) = 100 microm) and effectively crosses the blood-brain barrier at rates similar to the ones found for agents such as morphine and [Met]enkephalin that have potent central nervous system activity (P < or = 0.05). Daily oral noscapine treatment (300 mg/kg) administered to immunodeficient mice having stereotactically implanted rat C6 glioblasoma into the striatum revealed a significant reduction of tumor volume (P < or = 0.05). This was achieved with no identifiable toxicity to the duodenum, spleen, liver, or hematopoietic cells as determined by pathological microscopic examination of these tissues and flow cytometry. Furthermore, noscapine treatment resulted in little evidence of toxicity to dorsal root ganglia cultures as measured by inhibition of neurite outgrowth and yielded no evidence of peripheral neuropathy in animals. However, evidence of vasodilation was observed in noscapine-treated brain tissue. These unique properties of noscapine, including its ability to cross the blood-brain barrier, interfere with microtubule dynamics, arrest tumor cell division, reduce tumor growth, and minimally affect other dividing tissues and peripheral nerves, warrant additional investigation of its therapeutic potential.

Noscapine alters microtubule dynamics in living cells and inhibits the progression of melanoma.

Cellular microtubules, polymers of tubulin, alternate relentlessly between phases of growth and shortening. We now show that noscapine, a tubulin-binding agent, increases the time that cellular microtubules spend idle in a paused state. As a result, most mammalian cell types observed arrest in mitosis in the presence of noscapine. We demonstrate that noscapine-treated murine melanoma B16LS9 cells do not arrest in mitosis but rather become polyploid followed by cell death, whereas primary melanocytes reversibly arrest in mitosis and resume a normal cell cycle after noscapine removal. Furthermore, in a syngeneic murine model of established s.c. melanoma, noscapine treatment resulted in an 85% inhibition of tumor volume on day 17 when delivered by gavage compared with untreated animals (P

Minor alteration of microtubule dynamics causes loss of tension across kinetochore pairs and activates the spindle checkpoint.

We have previously identified the opium alkaloid noscapine as a microtubule interacting agent that binds stoichiometrically to tubulin and alters its conformation. Here we show that, unlike many other microtubule inhibitors, noscapine does not significantly promote or inhibit microtubule polymerization. Instead, it alters the steady-state dynamics of microtubule assembly, primarily by increasing the amount of time that the microtubules spend in an attenuated (pause) state. Further studies reveal that even at high concentrations, noscapine does not alter the tubulin polymer/monomer ratio in HeLa cells. Cells treated with noscapine arrest at mitosis with nearly normal bipolar spindles. Strikingly, although most of the chromosomes in these cells are aligned at the metaphase plate, the rest remain near the spindle poles, both of which exhibit loss of tension across kinetochore pairs. Furthermore, levels of the spindle checkpoint proteins Mad2, Bub1, and BubR1 decrease by 138-, 3.7-, and 3.9-fold, respectively, at the kinetochore region upon chromosome alignment. Our results thus suggest that an exquisite control of microtubule dynamics is required for kinetochore tension generation and chromosome alignment during mitosis. Our data also support the idea that Mad2 and Bub1/BubR1 respond to kinetochore-microtubule attachment and/or tension to different degrees.