A study published Online First by Archives of Neurology, a JAMA Network publication, reveals that patients with mild to moderate Alzheimer disease who received immunotherapy with the antibody bapineuzumab showed decreases in a cerebrospinal fluid biomarker. According to the researchers the results may indicate subsequent effects on the degenerative process.

According to background information in the article, Alzheimer disease (AD) is a progressive neurodegenerative disease. Amongst other characteristics, AD patients have deposits of extracellular β-amyloid (Aβ) plaques and intraneuronal neurofibrillary tangles, together with decreases in cerebrospinal fluid (CSF) Aβ and higher levels of CSF tau proteins.

The researchers write that one of the largest disease-modifying methods currently evaluated for AD is bapineuzumab, which is an anti-Aβ monoclonal antibody, as well as immunotherapies with antibodies against Aβ.

In order to assess whether bapineuzumab affected the CSF levels of the downstream biomarkers, total tau (T-tau) and phosphorylated tau (P-tau), as well as the primary biomarker Aβ, Kaj Blennow, M.D., Ph.D., of the University of Gothenburg, Sweden, and colleagues examined two double-blind, placebo-controlled trials. Of the 46 individuals with mild to moderate Alzheimer disease participating in the trials, 27 received bapineuzumab and 19 received placebo.

The researchers explained:

“The reduction in the downstream biomarker CSF P-tau following treatment with bapineuzumab suggests that bapineuzumab reduces brain levels of P-tau, which may also reduce the formation of tangles in the brain.”

The team found a reduction in CSF T-tau, although compared with placebo, the reduction did not reach statistical significance. According to the study results there was no clear differences observed for CSF Aβ. The researchers state that further examinations are required for the observed decrease in P-tau and T-tau.

The researchers conclude:

“An important question remains whether such changes is CSP biomarkers correlate with clinical benefit. This question will be addressed in the ongoing bapineuzumab phase 3 trials.”

Written by Grace Rattue