Long-Term Follow Up of Patients with Mild-to-Moderate Alzheimer's Disease Treated with Bapineuzumab in a Phase III, Open-Label, Extension Study.

BACKGROUND: A 3-year extension of two Phase III parent studies of intravenous (IV) bapineuzumab in patients with mild-to-moderate Alzheimer's disease dementia (apolipoprotein (APOE) ɛ4 carriers and noncarriers) is summarized. OBJECTIVES: The primary and secondary objectives were to evaluate the long-term safety, tolerability, and maintenance of efficacy of bapineuzumab. METHODS: A multicenter study in patients who had participated in double-blind placebo-controlled parent studies. Patients enrolled in the extension study were assigned to receive IV infusions of bapineuzumab (0.5 or 1.0 mg/kg) every 13 weeks until termination but were blinded to whether they had received bapineuzumab or placebo in the parent studies. RESULTS: A total of 1,462 (688 were APOEɛ4 carriers and 774 were noncarriers) patients were enrolled. Extension-onset adverse events occurred in >81% of the patients in each dose group. Fall, urinary tract infection, agitation, and ARIA-E occurred in ≥10% of participants. The incidence proportion of ARIA-E was higher among carriers and noncarriers who received bapineuzumab for the first time in the extension study (11.8% and 5.4%, respectively) versus those who were previously exposed in the parent studies (5.1% and 1.3%, respectively). After 6 to 12 months exposure to bapineuzumab IV in the extension study, similar deterioration of cognition and function occurred with no significant differences between the dose groups. CONCLUSIONS: Infusion of bapineuzumab 0.5 or 1.0 mg/kg every 13 weeks for up to 3 years was generally well tolerated, with a safety and tolerability profile similar to that in previous studies.

Long-term safety and tolerability of bapineuzumab in patients with Alzheimer's disease in two phase 3 extension studies.

BACKGROUND: Immunotherapy with monoclonal antibodies that target amyloid beta has been under investigation as a treatment for patients with Alzheimer's disease (AD). The 3000 and 3001 phase 3 clinical studies of intravenous bapineuzumab assessed safety and efficacy in patients with mild to moderate AD recruited in over 26 countries. This article describes the long-term safety and tolerability of bapineuzumab in the extension studies for these two protocols. METHODS: The long-term safety and tolerability of intravenous-administered bapineuzumab in patients with AD was evaluated in apolipoprotein E ε4 allele noncarriers (Study 3002, extension of Study 3000) and apolipoprotein E ε4 allele carriers (Study 3003, extension of Study 3001). Those receiving bapineuzumab in the parent study were continued at the same dose; if receiving placebo, patients began bapineuzumab. Bapineuzumab doses were 0.5 mg/kg in both studies and also 1.0 mg/kg in the noncarrier study. Clinical efficacy of bapineuzumab was also assessed in exploratory analyses. RESULTS: Because of lack of efficacy in two other phase 3 trials, the parent protocols were stopped early. As a result, Studies 3002 and 3003 were also terminated. In total, 492 and 202 patients were enrolled in Studies 3003 and 3002, respectively. In apolipoprotein E ε4 carriers (Study 3003), treatment-emergent adverse events occurred in 70.7% of the patients who originally received placebo and 66.9% of those who originally received bapineuzumab. In noncarriers, treatment-emergent adverse events occurred in 82.1% and 67.6% of patients who received placebo + bapineuzumab 0.5 mg/kg and placebo + bapineuzumab 1.0 mg/kg, respectively, and in 72.7% and 64.3% of those who received bapineuzumab + bapineuzumab 0.5 mg/kg and 1.0 mg/kg, respectively. Amyloid-related imaging abnormalities with edema or effusions were the main bapineuzumab-associated adverse events in both studies, occurring in approximately 11% of placebo + bapineuzumab and 4% of bapineuzumab + bapineuzumab groups overall. Exploratory analyses of clinical efficacy were not significantly different between groups in either study. CONCLUSIONS: In these phase 3 extension studies, intravenous bapineuzumab administered for up to approximately 3 years showed no unexpected safety signals and a safety profile consistent with previous bapineuzumab trials. TRIAL REGISTRATION: Noncarriers (Study 3002): ClinicalTrials.gov NCT00996918 . Registered 14 October 2009. Carriers (Study 3003): ClinicalTrials.gov NCT00998764 . Registered 16 October 2009.

Bapineuzumab for mild to moderate Alzheimer's disease in two global, randomized, phase 3 trials.

BACKGROUND: Our objective was to evaluate the efficacy (clinical and biomarker) and safety of intravenous bapineuzumab in patients with mild to moderate Alzheimer's disease (AD). METHODS: Two of four phase 3, multicenter, randomized, double-blind, placebo-controlled, 18-month trials were conducted globally: one in apolipoprotein E ε4 carriers and another in noncarriers. Patients received bapineuzumab 0.5 mg/kg (both trials) or 1.0 mg/kg (noncarrier trial) or placebo every 13 weeks. Coprimary endpoints were change from baseline to week 78 on the 11-item Alzheimer's Disease Assessment Scale-Cognitive subscale and the Disability Assessment for Dementia. RESULTS: A total of 683 and 329 patients completed the current carrier and noncarrier trials, respectively, which were terminated prematurely owing to lack of efficacy in the two other phase 3 trials of bapineuzumab in AD. The current trials showed no significant difference between bapineuzumab and placebo for the coprimary endpoints and no effect of bapineuzumab on amyloid load or cerebrospinal fluid phosphorylated tau. (Both measures were stable over time in the placebo group.) Amyloid-related imaging abnormalities with edema or effusion were confirmed as the most notable adverse event. CONCLUSIONS: These phase 3 global trials confirmed lack of efficacy of bapineuzumab at tested doses on clinical endpoints in patients with mild to moderate AD. Some differences in the biomarker results were seen compared with the other phase 3 bapineuzumab trials. No unexpected adverse events were observed. TRIAL REGISTRATION: Noncarriers (3000) ClinicalTrials.gov identifier NCT00667810 ; registered 24 Apr 2008. Carriers (3001) ClinicalTrials.gov identifier NCT00676143 ; registered 2 May 2008.

Cognition in MCI and Alzheimer's disease: baseline data from a longitudinal study of the NTB.

Baseline data are summarized from a study examining the psychometric properties of the Neuropsychological Test Battery (NTB) and its subtests, and correlating the NTB with other cognitive and functional assessments. A multicenter, longitudinal, non-interventional study included mild to moderate Alzheimer's disease (AD, n = 196), mild cognitive impairment (MCI, n = 70), or normal cognition participants (NC, n = 75). The NTB, other cognitive assessment tools, functional/behavioral questionnaires, and health outcome assessments were administered. At baseline composite NTB, NTB memory, and NTB executive function z-scores were significantly lower for participants with AD compared with MCI, and for participants with MCI compared with NC. The composite NTB z-score had high test-retest reliability between screening and baseline. The results of this study suggest that NTB exhibits good reliability in patients with mild to moderate AD and MCI.

Amyloid-related imaging abnormalities in amyloid-modifying therapeutic trials: recommendations from the Alzheimer's Association Research Roundtable Workgroup.

Amyloid imaging related abnormalities (ARIA) have now been reported in clinical trials with multiple therapeutic avenues to lower amyloid-ß burden in Alzheimer's disease (AD). In response to concerns raised by the Food and Drug Administration, the Alzheimer's Association Research Roundtable convened a working group to review the publicly available trial data, attempts at developing animal models, and the literature on the natural history and pathology of related conditions. The spectrum of ARIA includes signal hyperintensities on fluid attenuation inversion recoverysequences thought to represent "vasogenic edema" and/or sulcal effusion (ARIA-E), as well as signal hypointensities on GRE/T2* thought to represent hemosiderin deposits (ARIA-H), including microhemorrhage and superficial siderosis. The etiology of ARIA remains unclear but the prevailing data support vascular amyloid as a common pathophysiological mechanism leading to increased vascular permeability. The workgroup proposes recommendations for the detection and monitoring of ARIA in ongoing AD clinical trials, as well as directions for future research.

A single ascending dose study of bapineuzumab in patients with Alzheimer disease.

The safety, tolerability, and pharmacokinetics (PKs) of bapineuzumab (AAB-001), a humanized monoclonal antibody to amyloid beta, were evaluated in patients with mild-to-moderate Alzheimer disease in a phase 1, randomized, third-party unblinded, placebo-controlled, single ascending dose trial. Thirty patients received bapineuzumab infusion of 0.5, 1.5, or 5 mg/kg or placebo (6 active, 2 placebo for 0.5 and 1.5-mg/kg cohorts; 10 active, 4 placebo for 5.0-mg/kg cohort). Three patients in the highest dose cohort (5.0 mg/kg) developed magnetic resonance imaging abnormalities consistent with vasogenic edema, predominantly high signal abnormalities on fluid-attenuated inversion recovery sequences, all of which resolved over time. Plasma amyloid beta was elevated from baseline, peaking approximately 24 hours after infusion. PK analysis demonstrated a half-life of 21 to 26 days, supporting a 13-week dosing interval for bapineuzumab. This small, single-dose study demonstrated the safety profile and PK characteristics of bapineuzumab and was used to design later safety and efficacy trials.

Progress in the active immunotherapeutic approach to Alzheimer's disease: clinical investigations into AN1792-associated meningoencephalitis.

BACKGROUND: In a phase 2a clinical trial of AN1792 (Study 201), a potential immunotherapeutic agent for use in Alzheimer's disease (AD), approximately 6% of the treated AD patients (18/300) developed meningoencephalitis (ME). OBJECTIVE: To elucidate potential immune mechanisms of treatment-induced ME. METHODS: Peripheral blood mononuclear cells obtained from patients who received AN1792 were stimulated in vitro either with beta-amyloid (Abeta) or various overlapping peptides of Abeta(1-42), followed by quantification of cytokine-secreting cells by enzyme-linked immunosorbent spot assay. RESULTS: A significant difference in the quality of the T-cell responses between patients in Study 201 and those in earlier studies of AN1792 was noted. T-cell responses specific to the carboxy terminus of Abeta elicited from patients' peripheral blood mononuclear cells in an earlier multiple dose study (Study 102) were Th2 biased, while those from Study 201 were biased toward a proinflammatory Th1 response. Antibody responses in both studies were quantitatively and qualitatively similar (as determined by epitope mapping). The addition of polysorbate 80 to the formulation used in Study 201 is the most likely explanation for the difference in the T-cell response. CONCLUSION: ME following injection of AN1792 may be related to immune response differences driven by a formulation change. To address this, a novel peptide-carrier protein conjugate using an amino-terminal fragment of Abeta (ACC-001) has been developed to avoid potentially harmful T-cell responses, while maintaining a similar antibody response to that of AN1792. Immunotherapeutic trials using this treatment approach in AD patients are in progress.

Volumetric MRI and cognitive measures in Alzheimer disease : comparison of markers of progression.

BACKGROUND: Both cognitive tests and MRI-based measures have been suggested as outcomes in trials assessing disease-modifying therapies in Alzheimer's disease (AD). OBJECTIVE: To compare changes in longitudinal MRI measures with changes in performance on cognitive tests routinely used in AD clinical trials. METHOD: Fifty-two subjects from the placebo-arm of a clinical trial in mild-to-moderate AD had volumetric T(1)-weighted scans and cognitive tests including the Mini-Mental State Examination (MMSE), AD Assessment Scale-Cognitive Subscale, Disability Assessment for Dementia, AD Cooperative Study-Clinical Global Impression of Change and Clinical Dementia Rating at baseline and one-year later. Rates of brain atrophy and ventricular enlargement were measured using the boundary shift integral. Hippocampal (Hc) atrophy was calculated from manual volume measurements. The relationships between MRI and cognitive measures were investigated. RESULTS: Rates of brain atrophy and/or ventricular enlargement were correlated with declining performance on cognitive scales. The strongest association was between brain atrophy rate and MMSE decline (r = 0.59, p < 0.0001). Hc atrophy rate was not significantly correlated with any of the cognitive scales. CONCLUSION: The lack of correlation between Hc atrophy and cognitive scales may reflect a combination of: the extensive functional damage to the Hc by the time AD is clinically established, the greater influence of ongoing cortical degeneration, and errors in Hc outlining. The strong correlations between brain atrophy and ventricular enlargement, and cognitive scales probably reflect the correspondence between these measures of overall cerebral loss and global cognitive measures in the moderate stages of AD.

A neuropsychological test battery for use in Alzheimer disease clinical trials.

OBJECTIVE: To report the psychometric properties of an alternative instrument to the cognitive subscale of the Alzheimer's Disease Assessment Scale, a neuropsychological test battery (NTB) for measuring drug efficacy in Alzheimer disease clinical trials. DESIGN: The NTB was evaluated in a randomized, double-blind, placebo-controlled trial of AN1792(QS-21) (synthetic beta-amyloid plus an adjuvant) (300 patients) and isotonic sodium chloride solution (72 patients). The test-retest reliability of the NTB was examined, and the NTB was correlated with other cognitive (cognitive subscale of the Alzheimer's Disease Assessment Scale and Mini-Mental State Examination) and functional (Disability Assessment Scale for Dementia and Clinical Dementia Rating Sum of Boxes) measures. In addition, a factor analysis was performed on NTB components. Finally, the sensitivity of the NTB to change was assessed as a function of Mini-Mental State Examination performance. RESULTS: The NTB had high test-retest reliability at 6 (Pearson product moment correlation [r] = 0.92) and 12 (r = 0.88) months. Internal consistency was high (Cronbach alpha = 0.84). The correlations between the NTB z score and scores on traditional measures of cognition and function were significantly different from 0 (P < .001). A factor analysis yielded "memory" and "executive function" factors. The NTB z score declined linearly over 1 year in patients receiving placebo and, in contrast to the Alzheimer's Disease Assessment Scale cognitive subscale, demonstrated similar declines in patients with high (21-26) and low (15-20) Mini-Mental State Examination scores at baseline. CONCLUSIONS: The NTB exhibits excellent psychometric properties and seems to be a reliable and sensitive measure of cognitive change in patients with mild to moderate Alzheimer disease. The psychometric properties of the NTB suggest that it may have particular utility in evaluating drug efficacy in clinical trials in which patients with mild Alzheimer disease are included.

Absence of beta-amyloid deposits after immunization in Alzheimer disease with Lewy body dementia.

OBJECTIVE: To describe the neuropathological and biochemical findings of the brain examination of a patient enrolled in the AN-1792(QS-21) trial with an initial clinical diagnosis of Alzheimer disease (AD), in whom Lewy body variant was thereafter clinically diagnosed. DESIGN: A case report. SETTING: University memory clinic. Patient A 74-year-old woman with clinical features of probable AD. Intervention The patient received 2 injections of 225 mug of AN-1792 (beta-amyloid [Abeta]) plus 50 mug of the adjuvant QS-21 at an interval of 4 weeks. The patient was an antibody responder with an IgG anti-AN-1792 antibody titer exceeding 10 000 and an IgM titer exceeding 3500. Maximum serum anti-Abeta titers were reached in 4.7 months. During the 3 following years, while the Mini-Mental State Examination score remained globally stable despite several confusional episodes, she developed clinical features of dementia with Lewy bodies. The patient died 34 months postimmunization. An autopsy was performed. MAIN OUTCOME MEASURES: Neuropathological and biochemical examination of the brain using standardized evaluation for tau, beta-amyloid, and synuclein deposits. RESULTS: Neither neuropathological nor biochemical examinations showed amyloid deposit in the brain of this immunized patient. For tau deposition, Braak stage was IV/VI, and the Western blot analysis score was 9c/10. The neuropathological semiquantitative score for alpha-synuclein aggregation was 4. There was no inflammation. These results were compared with those of an age-matched patient with AD and a control devoid of any neurological disease. CONCLUSION: In this Lewy body variant case, with globally stable functional and cognitive features, Abeta immunization resulted in a significant clearance of amyloid deposits, with remaining tau and synuclein pathological features in the brain. Patients with a Lewy body variant of AD should not be excluded from enrollment in Abeta-immunization trials.

Risk factors associated with beta-amyloid(1-42) immunotherapy in preimmunization gene expression patterns of blood cells.

BACKGROUND: A phase 2a, double-blind, placebo-controlled, multicenter study was conducted to evaluate safety, tolerability, and pilot efficacy of immunization with beta-amyloid((1-42)) in patients with Alzheimer disease. Six immunizations were planned but were halted when meningoencephalitis was recognized as an adverse event in 6% of immunized patients. OBJECTIVE: To identify biomarkers associated with both the risk of meningoencephalitis and antibody responsiveness. PARTICIPANTS: One hundred fifty-three patients with mild to moderate Alzheimer disease.Main Outcome Measure Association between response to immunization and preimmunization expression levels of 8239 messenger RNA transcripts expressed in peripheral blood mononuclear cells that had been collected at the screening visit. RESULTS: Expression patterns of genes related to apoptosis and proinflammatory pathways (tumor necrosis factor pathway in particular) were identified as biomarkers of risk for the development of meningoencephalitis. Expression patterns of genes related to protein synthesis, protein trafficking, DNA recombination, DNA repair, and cell cycle were strongly associated with IgG response to immunization. CONCLUSIONS: Candidate biomarkers associated with risk of immunotherapy-related meningoencephalitis were detected in blood collected prior to treatment. In addition, a different set of biomarkers were identified that were associated with the desired outcome of IgG response.

Abeta42 immunization in Alzheimer's disease generates Abeta N-terminal antibodies.

Serum samples from Alzheimer's disease (AD) patients immunized with Abeta42 (AN1792) were analyzed to determine the induced antibody properties including precise amyloid-beta peptide (Abeta) epitopes and amyloid plaque-binding characteristics. The predominant response in these patients is independent of whether or not meningoencephalitis developed and is against the free amino terminus of Abeta. The immunostaining of amyloid plaques in brain tissue by patient sera is adsorbable by a linear Abeta1-8 peptide, demonstrating that the antibodies are directed predominantly to this epitope and not dependent on Abeta conformations or aggregates specific to plaques. Furthermore, the antibodies are not capable of binding amyloid precursor protein and would be predicted to be competent in facilitating clearance of amyloid plaques in AD brains.