Blennow K, Zetterberg H, Rinne JO, et al. Effect of Immunotherapy With Bapineuzumab on Cerebrospinal Fluid Biomarker Levels in Patients With Mild to Moderate Alzheimer Disease. Arch Neurol:archneurol.2012.90. Arch Neurol -- Effect of Immunotherapy With Bapineuzumab on Cerebrospinal Fluid Biomarker Levels in Patients With Mild to Moderate Alzheimer Disease, April 2, 2012, Blennow et al. 0 (2012): archneurol.2012.90v1
Background Given the slow and variable clinical course of Alzheimer disease, very large and extended clinical trials are needed to identify a beneficial clinical effect of disease-modifying treatments. Therefore, biomarkers are essential to prove that an anti–?-amyloid (A?) drug candidate affects both A? metabolism and plaque load as well as downstream pathogenic mechanisms.
Objective To evaluate the effect of the anti-A? monoclonal antibody bapineuzumab on cerebrospinal fluid (CSF) biomarkers reflecting A? homeostasis, neuronal degeneration, and tau-related pathology in patients with Alzheimer disease.
Design Two phase 2, multicenter, randomized, double-blind, placebo-controlled clinical trials of 12-month duration.
Setting Academic centers in the United States (Study 201) and England and Finland (Study 202).
Patients Forty-six patients with mild to moderate Alzheimer disease.
Interventions Patients received either placebo (n = 19) or bapineuzumab (n = 27) in 3 or 4 ascending dose groups.
Main Outcome Measures Changes between end of study and baseline in the exploratory CSF biomarkers A?1-42, A?X-42, A?X-40; total tau (T-tau); and phosphorylated tau (P-tau).
Results Within the bapineuzumab group, a decrease at end of study compared with baseline was found both for CSF T-tau (–72.3 pg/mL) and P-tau (–9.9 pg/mL). When comparing the treatment and placebo groups, this difference was statistically significant for P-tau (P = .03), while a similar trend for a decrease was found for T-tau (P = .09). No clear-cut differences were observed for CSF A?.
Conclusions To our knowledge, this study is the first to show that passive A? immunotherapy with bapineuzumab results in decreases in CSF T-tau and P-tau, which may indicate downstream effects on the degenerative process. Cerebrospinal fluid biomarkers may be useful to monitor the effects of novel disease-modifying anti-A? drugs in clinical trials.