Safety and Dose-Response of Vidofludimus Calcium in Relapsing Multiple Sclerosis: Extended Results of a Placebo-Controlled Phase 2 Trial

BACKGROUND AND OBJECTIVES

Vidofludimus calcium suppressed MRI disease activity compared with placebo in patients with relapsing-remitting multiple sclerosis (RRMS) in the first cohort of the phase 2 EMPhASIS study. Because 30 mg and 45 mg showed comparable activity on multiple end points, the study enrolled an additional low-dose cohort to further investigate a dose-response relationship.

METHODS

In a randomized, placebo-controlled, phase 2 trial, patients with RRMS, aged 18-55 years, and with ≥2 relapses in the last 2 years or ≥1 relapse in the last year, and ≥1 gadolinium-enhancing brain lesion in the last 6 months. Patients were randomly assigned (1:1:1) vidofludimus calcium (30 or 45 mg) or placebo in cohort 1 and vidofludimus calcium (10 mg) or placebo (4:1) in cohort 2 for 24 weeks. The primary end point was the cumulative number of combined unique active (CUA) lesions at week 24. Secondary end points were clinical outcomes and safety.

RESULTS

Across cohorts 1 and 2, 268 patients were randomized to placebo (n = 81), 10 mg (n = 47) vidofludimus calcium, 30 mg (n = 71) vidofludimus calcium, or 45 mg (n = 69) vidofludimus calcium. The mean cumulative CUA lesions over 24 weeks was 5.8 (95% CI 4.1-8.2) for placebo, 5.9 (95% CI 3.9-9.0) for 10 mg treatment group, 1.4 (95% CI 0.9-2.1) for 30 mg treatment group, and 1.7 (95% CI 1.1-2.5) for 45 mg treatment group. Serum neurofilament light chain decreased in a dose-dependent manner. The number of patients with confirmed disability worsening after 24 weeks was 3 (3.7%) patients receiving placebo and 3 (1.6%) patients receiving any dose of vidofludimus calcium. Treatment-emergent adverse events occurred in 35 (43%) placebo patients compared with 11 (23%) and 71 (37%) patients in the 10 mg or any dose of vidofludimus calcium groups, respectively. The incidence of liver enzyme elevations and infections were similar between placebo and any dose of vidofludimus calcium. No new safety signals were observed.

DISCUSSION

Compared with placebo, vidofludimus calcium suppressed the development of new brain lesions with daily doses of 30 mg and 45 mg, but not 10 mg, establishing the lowest efficacious dose is 30 mg.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that among adults with active RRMS and ≥1 Gd+ brain lesion in the past 6 months, the cumulative number of active lesions decreased with vidofludimus calcium.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov (NCT03846219) and EudraCT (2018-001896-19).

Sensitivity of Individual and Composite Test Scores from the Cogstate Brief Battery to Mild Cognitive Impairment and Dementia Due to Alzheimer's Disease

BACKGROUND

The Cogstate Brief Battery (CBB) is a computerized cognitive test battery used commonly to identify cognitive deficits related to Alzheimer's disease (AD). However, AD and normative samples used to understand the sensitivity of the CBB to AD in the clinic have been limited, as have the outcome measures studied.

OBJECTIVE

This study investigated the sensitivity of CBB outcomes, including potential composite scores, to cognitive impairment in mild cognitive impairment (MCI) and dementia due to AD, in carefully selected samples.

METHODS

Samples consisted of 4,871 cognitively unimpaired adults and 184 adults who met clinical criteria for MCI (Clinical Dementia Rating (CDR) = 0.5) or dementia (CDR > 0.5) due to AD and CBB naive. Speed and accuracy measures from each test were examined, and theoretically- and statistically-derived composites were created. Sensitivity and specificity of classification of cognitive impairment were compared between outcomes.

RESULTS

Individual CBB measures of learning and working memory showed high discriminability for AD-related cognitive impairment for CDR 0.5 (AUCs ∼ 0.79-0.88), and CDR > 0.5 (AUCs ∼ 0.89-0.96) groups. Discrimination ability for theoretically derived CBB composite measures was high, particularly for the Learning and Working Memory (LWM) composite (CDR 0.5 AUC = 0.90, CDR > 0.5 AUC = 0.97). As expected, statistically optimized linear composite measures showed strong discrimination abilities albeit similar to the LWM composite.

CONCLUSIONS

In older adults, the CBB is effective for discriminating cognitive impairment due to MCI or AD-dementia from unimpaired cognition with the LWM composite providing the strongest sensitivity.

ADAMANT: a placebo-controlled randomized phase 2 study of AADvac1, an active immunotherapy against pathological tau in Alzheimer's disease

Alzheimer's disease (AD) pathology is partly characterized by accumulation of aberrant forms of tau protein. Here we report the results of ADAMANT, a 24-month double-blinded, parallel-arm, randomized phase 2 multicenter placebo-controlled trial of AADvac1, an active peptide vaccine designed to target pathological tau in AD (EudraCT 2015-000630-30). Eleven doses of AADvac1 were administered to patients with mild AD dementia at 40 μg per dose over the course of the trial. The primary objective was to evaluate the safety and tolerability of long-term AADvac1 treatment. The secondary objectives were to evaluate immunogenicity and efficacy of AADvac1 treatment in slowing cognitive and functional decline. A total of 196 patients were randomized 3:2 between AADvac1 and placebo. AADvac1 was safe and well tolerated (AADvac1 n = 117, placebo n = 79; serious adverse events observed in 17.1% of AADvac1-treated individuals and 24.1% of placebo-treated individuals; adverse events observed in 84.6% of AADvac1-treated individuals and 81.0% of placebo-treated individuals). The vaccine induced high levels of IgG antibodies. No significant effects were found in cognitive and functional tests on the whole study sample (Clinical Dementia Rating-Sum of the Boxes scale adjusted mean point difference -0.360 (95% CI -1.306, 0.589)), custom cognitive battery adjusted mean z-score difference of 0.0008 (95% CI -0.169, 0.172). We also present results from exploratory and post hoc analyses looking at relevant biomarkers and clinical outcomes in specific subgroups. Our results show that AADvac1 is safe and immunogenic, but larger stratified studies are needed to better evaluate its potential clinical efficacy and impact on disease biomarkers.

AADvac1, an Active Immunotherapy for Alzheimer's Disease and Non Alzheimer Tauopathies: An Overview of Preclinical and Clinical Development

Neurofibrillary tau protein pathology is closely associated with the progression and phenotype of cognitive decline in Alzheimer's disease and other tauopathies, and a high-priority target for disease-modifying therapies. Herein, we provide an overview of the development of AADvac1, an active immunotherapy against tau pathology, and tau epitopes that are potential targets for immunotherapy. The vaccine leads to the production of antibodies that target conformational epitopes in the microtubule-binding region of tau, with the aim to prevent tau aggregation and spreading of pathology, and promote tau clearance. The therapeutic potential of the vaccine was evaluated in transgenic rats and mice expressing truncated, non mutant tau protein, which faithfully replicate of human tau pathology. Treatment with AADvac1 resulted in reduction of neurofibrillary pathology and insoluble tau in their brains, and amelioration of their deleterious phenotype. The vaccine was highly immunogenic in humans, inducing production of IgG antibodies against the tau peptide in 29/30 treated elderly patients with mild-to-moderate Alzheimer's. These antibodies were able to recognise insoluble tau proteins in Alzheimer patients' brains. Treatment with AADvac1 proved to be remarkably safe, with injection site reactions being the only adverse event tied to treatment. AADvac1 is currently being investigated in a phase 2 study in Alzheimer's disease, and a phase 1 study in non-fluent primary progressive aphasia, a neurodegenerative disorder with a high tau pathology component.

Neuroimaging biomarkers for clinical trials in atypical parkinsonian disorders: Proposal for a Neuroimaging Biomarker Utility System

INTRODUCTION

Therapeutic strategies targeting protein aggregations are ready for clinical trials in atypical parkinsonian disorders. Therefore, there is an urgent need for neuroimaging biomarkers to help with the early detection of neurodegenerative processes, the early differentiation of the underlying pathology, and the objective assessment of disease progression. However, there currently is not yet a consensus in the field on how to describe utility of biomarkers for clinical trials in atypical parkinsonian disorders.

METHODS

To promote standardized use of neuroimaging biomarkers for clinical trials, we aimed to develop a conceptual framework to characterize in more detail the kind of neuroimaging biomarkers needed in atypical parkinsonian disorders, identify the current challenges in ascribing utility of these biomarkers, and propose criteria for a system that may guide future studies.

RESULTS

As a consensus outcome, we describe the main challenges in ascribing utility of neuroimaging biomarkers in atypical parkinsonian disorders, and we propose a conceptual framework that includes a graded system for the description of utility of a specific neuroimaging measure. We included separate categories for the ability to accurately identify an intention-to-treat patient population early in the disease (Early), to accurately detect a specific underlying pathology (Specific), and the ability to monitor disease progression (Progression).

DISCUSSION

We suggest that the advancement of standardized neuroimaging in the field of atypical parkinsonian disorders will be furthered by a well-defined reference frame for the utility of biomarkers. The proposed utility system allows a detailed and graded description of the respective strengths of neuroimaging biomarkers in the currently most relevant areas of application in clinical trials.

FUNDAMANT: an interventional 72-week phase 1 follow-up study of AADvac1, an active immunotherapy against tau protein pathology in Alzheimer's disease

Background

Neurofibrillary pathology composed of tau protein is closely correlated with severity and phenotype of cognitive impairment in patients with Alzheimer’s disease and non-Alzheimer’s tauopathies. Targeting pathological tau proteins via immunotherapy is a promising strategy for disease-modifying treatment of Alzheimer’s disease. Previously, we reported a 24-week phase 1 trial on the active vaccine AADvac1 against pathological tau protein; here, we present the results of a further 72 weeks of follow-up on those patients.

Methods

We did a phase 1, 72-week, open-label study of AADvac1 in patients with mild to moderate Alzheimer’s disease who had completed the preceding phase 1 study. Patients who were previously treated with six doses of AADvac1 at monthly intervals received two booster doses at 24-week intervals. Patients who were previously treated with only three doses received another three doses at monthly intervals, and subsequently two boosters at 24-week intervals. The primary objective was the assessment of long-term safety of AADvac1 treatment. Secondary objectives included assessment of antibody titres, antibody isotype profile, capacity of the antibodies to bind to AD tau and AADvac1, development of titres of AADvac1-induced antibodies over time, and effect of booster doses; cognitive assessment via 11-item Alzheimer’s Disease Assessment Scale cognitive assessment (ADAS-Cog), Category Fluency Test and Controlled Oral Word Association Test; assessment of brain atrophy via magnetic resonance imaging (MRI) volumetry; and assessment of lymphocyte populations via flow cytometry.

Results

The study was conducted between 18 March 2014 and 10 August 2016. Twenty-six patients who completed the previous study were enrolled. Five patients withdrew because of adverse events. One patient was withdrawn owing to noncompliance. The most common adverse events were injection site reactions (reported in 13 [50%] of vaccinated patients). No cases of meningoencephalitis or vasogenic oedema were observed. New micro-haemorrhages were observed only in one ApoE4 homozygote. All responders retained an immunoglobulin G (IgG) antibody response against the tau peptide component of AADvac1 over 6 months without administration, with titres regressing to a median 15.8% of titres attained after the initial six-dose vaccination regimen. Booster doses restored previous IgG levels. Hippocampal atrophy rate was lower in patients with high IgG levels; a similar relationship was observed in cognitive assessment.

Conclusions

AADvac1 displayed a benign safety profile. The evolution of IgG titres over vaccination-free periods warrants a more frequent booster dose regimen. The tendency towards slower atrophy in MRI evaluation and less of a decline in cognitive assessment in patients with high titres is encouraging. Further trials are required to expand the safety database and to establish proof of clinical efficacy of AADvac1.

Trial registration

The studies are registered with the EU Clinical Trials Register and ClinicalTrials.gov: the preceding first-in-human study under EudraCT 2012-003916-29 and NCT01850238 (registered on 9 May 2013) and the follow-up study under EudraCT 2013-004499-36 and NCT02031198 (registered 9 Jan 2014), respectively.

Electronic supplementary material

The online version of this article (10.1186/s13195-018-0436-1) contains supplementary material, which is available to authorized users.