Results from a Phase II Study to Assess the Clinical and Immunological Activity of AFFITOPE® AD02 in Patients with Early Alzheimer's Disease.

ABSTRACT

OBJECTIVES: The primary objective of this clinical trial was to assess the clinical activity of various doses and formulations of AFFITOPE® AD02 following its repeated s.c. administration to patients with early Alzheimer´s disease (AD), based on the evaluation of cognitive and functional domains. DESIGN: It was designed as a randomized, placebo-controlled, parallel group, double blind, multicenter phase II trial with 10 regular outpatient visits and 6 telephone interviews. SETTING: The trial was performed at 32 sites in six countries. PARTICIPANTS: A total of 332 patients were enrolled and 265 patients completed the trial in 3 treatment groups with AD02 and 2 control groups with aluminum oxihydroxide, here named IMM-AD04. Patients were randomly assigned to 5 groups two doses of IMM-AD04, 25µg AD02 (in two different formulations) and 75µg AD02. INTERVENTION At months 0, 1, 2, 3, 9 and 15, each patient received a single s.c. injection of the corresponding preparations of AFFITOPE® AD02 or the control, IMM-AD04. MEASUREMENTS Co-primary efficacy outcomes included a measure of cognition (adapted AD Assessment Scale cognitive [aADAS cog]), and a measure of function (adapted AD Cooperative Trial Activities of Daily Living [aADCS-ADL]). A primary composite score was the sum of these two scores. RESULTS: Treatments were generally well tolerated and adverse events (AEs) were seen at similar rates across all treatment groups, with the exception that more injection site reactions were seen in the groups with a higher level of adjuvant. None of the AD02 groups showed a benefit over the IMM-AD04 controls for primary or exploratory efficacy outcomes. The control groups differed on aADCS-ADL and therefore couldn't be pooled (p=0.039). Unexpectedly, the 2mg IMM-AD04 showed statistically significant effects over the other groups on several clinical outcomes including aADAS-cog, aADL, Composite, ADAS-cog, CDR-sb, and QOL-AD Caregiver as well as two biomarker outcomes: right and total hippocampal volume (all p<0.05). 48% of patients in the IMM-AD04 2mg group had no decline in the composite outcome over 18 months compared to 17%-31% in the other groups, which is consistent with historical placebo groups. CONCLUSION: No significant treatment effects were seen for the investigational compound AD02. However, the IMM-AD04 2mg group showed statistically significant effects over all other groups on several clinical outcomes as well as a slowing of decline on right hippocampal volume. The data support further development of IMM-AD04 as a disease modifying agent in line with EMA/FDA definitions.