Baxter International reported that it will discontinue clinical trials testing the drug Gammagard, which is an immunoglobulin product, as a treatment for Alzheimer’s after it failed to halt mental decline caused by the disease in a late-stage clinical trial. Gammagard is the third Alzheimer’s drug to fail over the last 12 months. High hopes were held for Gammagard, as the drug is an intravenous immune system treatment made from natural antibodies taken from young, healthy blood donors, instead of man-made antibodies.
Currently, there are no licensed drugs that can slow the progression of Alzheimer’s, and currently approved medications only treat the symptoms of the disease. Alzheimer’s is the most common form of dementia, affecting 5.1 million Americans according to the National Institutes of Health. The disease progresses in three stages—an early, preclinical stage with no symptoms, a middle stage of mild cognitive impairment, and a final stage of Alzheimer’s dementia. The time from diagnosis to death varies—as little as 3 or 4 years if the person is older than 80 when diagnosed to as long as 10 or more years if the person is younger.
In the Baxter trial, patients who received 18 months of infusions with the drug Gammagard fared no better than a group of patients who were given a placebo. Data indicated that the drug did not significantly arrest the decline in either cognition or daily functioning when compared with a placebo.
Just last year, researchers reported that four patients who had received the maximum dose of Gammagard had unusually gone three years without any decline in several measures of cognition and daily functioning. Unfortunately, the small Phase 2 patient pool did not have the same observable results when expanded into the Phase 3 trial.
Baxter noted that it would discontinue other trials testing the drug as a treatment for mild to moderate forms of Alzheimer’s, as well as reassess its program to study the disease once a full analysis of the data derived from the study is completed.