It’s too soon to say if the monoclonal antibody bapineuzumab can cure or even prevent Alzheimer’s disease, but new information about its ability to affect Alzheimer’s biomarkers makes it a promising candidate.
As reported in the online April 2 Archives of Neurology, research teams based at the University of Gothenburg in Mölndal, Sweden, and at Brown University in Providence, R.I., have completed two 12-month trials—one in the United States and one in England and Finland—to evaluate the effects of bapineuzumab on 46 patients with mild to moderate Alzheimer’s disease.
Their intention was to determine whether immunotherapy with bapineuzumab would result in decreases in cerebrospinal fluid (CSF) biomarkers, which might in turn indicate downstream effects on the degenerative processes associated with Alzheimer’s.
“We evaluated whether bapineuzumab impacted the CSF levels of the downstream biomarkers total tau (T-tau) and phosphorylated tau (P-tau), and the primary biomarker beta-amyloid in these trials,” wrote lead author Kaj Blennow, M.D., Ph.D., who is associated with the Clinical Neurochemistry Laboratory of the Sahlgrenska Academy at the University of Gothenburg, and colleagues.
Blennow’s work has focused on the development of laboratory measures for clinical diagnosis and therapy monitoring in Alzheimer’s disease, with significant implications for both drug development and patient care. The European College of Neuropsychopharmacology (ECNP) awarded Blennow the 2010 ECNP Neuropsychopharmacology Award in recognition of his original and influential contributions to Alzheimer’s disease research.
Blennow’s previous work includes a 2009 JAMA publication that reported the results of a multicenter study that verified that CSF levels of beta-amyloid, T-tau, and P-tau can identify incipient Alzheimer’s with good accuracy.
In this latest report, Blennow and colleagues make the case for the use of these same biomarkers for assessing the efficacy of disease-modifying therapies, particularly those aimed at the treatment of Alzheimer’s. Historically, the identification of a beneficial clinical effect of Alzheimer’s treatments required very large and extended clinical trials.
Their results? In a pooled analysis of CSF data from the two trials of passive immunotherapy with bapineuzumab in patients with mild to moderate Alzheimer’s, a decrease in both P-tau and T-tau at the end of the study compared with baseline within the bapineuzumab group was observed. For CSF P-tau, a statistically significant treatment difference was observed between the bapineuzumab and placebo groups.
“These findings may indicate downstream effects of bapineuzumab treatment on the degenerative process,” explained Blennow and colleagues, who acknowledged that the important question is whether such changes in CSF biomarkers correlate with clinical benefit. They intend to address that question in the ongoing bapineuzumab phase 3 trials.
The study was funded by Elan (acquired by Janssen Alzheimer Immunotherapy in 2009) and Wyeth Pharmaceuticals (acquired by Pfizer in 2009). Employees of both sponsor companies were involved in the study design, collection, analysis, and interpretation of data, as well as in the development and submission of the scientific report.