Baxter's immunoglobulin therapy fails to meet goals of Alzheimer’s disease Phase III study

Baxter announced Tuesday that a late-stage trial of immunoglobulin failed to reduce cognitive decline and preserve functional abilities in patients with mild-to-moderate Alzheimer’s disease compared to placebo. The company noted that based on the results, current studies of immunoglobulin in mild-to-moderate Alzheimer’s disease will be discontinued and the drugmaker "will reconsider its current approach" in this area.

The GAP trial, which was initiated in 2008, enrolled 390 patients with mild-to-moderate Alzheimer’s disease who were randomised to receive one of two doses of immunoglobulin every two weeks or placebo. Top-line results showed that after 18 months there were no significant differences between either dose of immunoglobulin and placebo in the rate of cognitive decline or in functional ability. However, Baxter noted that in patients with moderate Alzheimer’s disease who carry the ApoE4 genetic marker, those given the higher dose of immunoglobulin demonstrated "a positive, numerical difference" in change from baseline versus placebo in measures of cognition. The company said the differences ranged between 16 percent and 29 percent.

''The study missed its primary endpoints, however we remain interested by the pre-specified sub-group analyses, particularly among patients with moderate disease and those who carry a genetic risk factor for Alzheimer’s disease," remarked Ludwig Hantson, president of Baxter’s BioScience unit. "A detailed analysis of the results from the GAP study continues," Hantson added. The company indicated that further data, including imaging, will be presented at the Alzheimer’s Association International Conference in July.

Baxter noted that in the GAP trial, immunoglobulin was well tolerated and that no new safety signals were identified. The company said that 17 serious adverse reactions were identified considered to be treatment related, with 12 in patients receiving immunoglobulin and five in those given placebo (for further analysis, read ViewPoints: Gammagard setback fuels notion that Alzheimer’s disease patients need to be treated earlier).

Baxter's immunoglobulin is marketed as Gammagard for the treatment of primary immunodeficiency disorders. The therapy is sold as Kiovig in the EU.

For more information on the Alzheimer's disease market landscape, see Therapy Trends: Alzheimer's Disease.

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