CHICAGO — Continuous infusions of immunoglobulin for 9 months stabilized cognition and function for Alzheimer's patients in a small placebo-controlled trial.
The 18-month-long phase II study included 24 patients with mild to moderate Alzheimer's. For the first 6 months, they were randomized either to placebo or to one of four intravenous immunoglobulin (IVIG) doses. For the remaining 12 months, all participants were switched to IVIG, but raters were still blinded to the dosing, said Dr. Norman Relkin, who presented the study's 9-month results at the International Conference on Alzheimer's Disease.
Patients who had received IVIG continuously for 9 months showed significantly better scores on measures of cognition and activities of daily living than did those taking placebo. When the IVIG arms were analyzed by dose, 0.4 g/kg of body weight every 2 weeks provided the best results in global functioning, cognition, and activities of daily living, Dr. Relkin said at the meeting, sponsored by the Alzheimer's Association.
Planning for a larger, phase III trial is underway; it is to be conducted at 35 academic centers in the United States.
Dr. Relkin of Cornell University, New York, coauthored another study that found that improvements in Alzheimer's patients treated with IVIG lasted only as long as the treatment continued. During the first 6 months of an 18-month trial, patients on IVIG gained a mean of nearly three points in the Alzheimer's Disease Assessment Scale for Cognition (ADAS-cog). In a 3-month washout, they lost almost all gain and did not recoup it when IVIG resumed over the next 9 months (doi:10.1016/j.neurobiolaging.2007.12.021).
The trial was cosponsored by Baxter International Inc. Dr. Relkin has financial ties to Baxter.