Washington, DC — An investigational treatment, Immune Globulin Intravenous (IGIV) has preserved the thinking abilities of a small group of mild-to-moderate Alzheimer’s patients and significantly reduced the rate of brain atrophy. Those are the findings of a small phase II study presented at the American Academy of Neurology (AAN) annual meeting in Toronto in mid-April. The next phase in clinical testing of this treatment (phase III) is underway at Georgetown’s Memory Disorders Program, a part of Georgetown University Medical Center, and other institutions nationwide.
“No doubt, these early findings are exciting, but we should be careful not to conclude that we’ve found a new treatment for Alzheimer’s,” says Scott Turner, MD, director of the Memory Disorders Program. “At the very least, the findings of the phase II study support continued evaluation of IGIV in the phase III study now underway.”
More about the phase II study results
The phase II data showed that patients who received IGIV once or twice a month for 18 months had significantly lower rates of ventricular enlargement (6.7% vs 12.7% per year) and less whole brain atrophy (1.6% vs 2.2% per year) than control subjects who initially received the placebo. The findings were based on two independent analyses of brain-imaging data from 20 patients who underwent serial MRI scans during the Phase 2 study of IGIV for Alzheimer’s disease (AD).
The brain of a typical AD patient shrinks three to four times faster than a healthy equivalent older adult due to the accelerated brain cell death. Shrinkage of brain tissue causes the fluid-filled ventricles at the brain’s center to enlarge at a faster rate than normal. Changes in the size of the brain and ventricles can be measured accurately by analyzing results from two or more MRI scans at intervals of several months apart. The unprecedented reductions in these measures after IGIV was administered in the Phase 2 study may indicate that IGIV exerts a disease-modifying effect that the current generation of AD treatments do not. The rates of brain shrinkage were independent of the subject’s age, gender and brain volume at the beginning of the study but strongly correlated with IGIV dose and the clinical outcomes after 18 months of intervention. The research team also found that patients who responded best to IGIV did not measurably decline over 18 months, plus had an average rate of brain shrinkage and average rate of ventricular enlargement comparable to the rate of normal elderly adults.
In addition, the study suggests that AD patients who received uninterrupted IGIV for 18 months showed significantly less decline in their overall function and thinking abilities than AD patients who were initially given the placebo.
The Phase 2 study was conducted at the New York Presbyterian Hospital/Weill Cornell Medical Center and was supported by Baxter Healthcare, the Citigroup Foundation and The Clinical Translational Science Center of Weill Cornell Medical College.
More about the phase III study of IGIV at GUMC
A phase III study of IGIV is underway at Georgetown and other institutions nationwide. IGIV is delivered intravenously. Participants will be treated intravenously every two weeks for 18 months. The first three infusions will occur at the General Clinical Research Center, located at Georgetown University Hospital. If the infusions are well-tolerated, the rest of the infusions may be done by a healthcare professional at the participant’s home (or other appropriate location). Visits to Georgetown are still necessary during the course of the clinical study to conduct testing and examinations.
This study is a phase III, double-blind, placebo-controlled study. Phase III means the investigational agent and its delivery has been studied in at least two earlier stages to assess safety and tolerability. Placebo–controlled means patients will be selected randomly to either receive the IGIV or an inactive substance so the agent can be assessed objectively. Adding to the study’s objectivity is that neither the doctor nor the patient will know if the study participant is receiving the active agent (double-blinded) until the end of the trial. About 360 people nationwide will participate.
The GUMC Memory Disorders Program is conducting several clinical studies for people with Alzheimer’s disease. Depending on the person’s medical status, he or she may qualify for this or other studies.
To learn how to participate in the study, contact Georgetown’s Memory Disorders Program at 202-784-6671 or visit the website at http://memory.georgetown.edu.
This study is funded by Baxter and National Institutes of Health (NIH) through the Alzheimer’s Disease Cooperative Study (ADCS). Georgetown University is being paid by the ADCS and Baxter to conduct this study. Turner, the study’s lead investigator at Georgetown, reports no related financial interests.
About Georgetown University Medical Center
Georgetown University Medical Center is an internationally recognized academic medical center with a three-part mission of research, teaching and patient care (through MedStar Health). GUMC’s mission is carried out with a strong emphasis on public service and a dedication to the Catholic, Jesuit principle of cura personalis — or “care of the whole person.” The Medical Center includes the School of Medicine and the School of Nursing and Health Studies, both nationally ranked, the world-renowned Lombardi Comprehensive Cancer Center and the Biomedical Graduate Research Organization (BGRO), home to 60 percent of the university’s sponsored research funding.