Baxter International’s immunodeficiency drug Gammagard has shown promise as a treatment for Alzheimer’s disease, demonstrating, for the first time, an improvement across cognitive, functional and physiological measures.

Results from a Phase II trial of the drug showed that, after 18 months of treatment, patients receiving Gammagard (immune globulin [human]) exhibited less cognitive decline than those in the placebo arm, dropping only six points on the Alzheimer’s Disease Assessment Scale-Cognitive Subscale score compared to 15, respectively.

In addition, patients taking the drug also showed an improvement in function, with those on Gammagard averaging around 1.36 points higher on the Alzheimer’s Disease Cooperative Study-Clinical Global Impression of Change rating than those taking a ghost pill.

Furthermore, MRI analyses showed that patients taking Baxter’s drug experienced lower mean annual ventricular enlargement (6.7%) than those in the control group (12.3%), as well as a 1.58% reduction in whole brain atrophy rates, adding further evidence in support of the drug’s potential to treat the disease.

According to Baxter, the Phase II trial marks the first study in Alzheimer’s disease where all three measures - cognitive, functional and neuroimaging - had positive data and were statistically significant, and the data “support continued evaluation for Alzheimer's disease in a larger number of patients”, said Paul Aisen, director of the Alzheimer’s Disease Cooperative Study.

New Phase III trial
The drug is already being assessed in a late-stage trial in patients with moderate-severe Alzheimer’s, and on the back of these latest findings, Baxter said it is planning on carrying out a second, concurrent Phase III study to confirm the Phase II data in more patients.

“The new study will collect additional evidence to support Gammagard’s use in mild-to-moderate Alzheimer’s disease and, with our ongoing Phase III study, support filing for registration in this indication,” confirmed Hartmut Ehrlich, vice president of research and development for Baxter BioScience.