A new DNA vaccine may be helpful for those who suffer from multiple sclerosis (MS), according to an article in this week’s online issue of Archives of Neurology (JAMA/Archives). The article explains that the vaccine works on the brain and immune system.
Myelin sheaths protect the nerve cells in the brain and spinal cord – the immune system of MS patients attacks this sheath, eventually destroying the nerve cell’s axon and stopping the transmission of messages to other neurons. It is believed that the immune cells and antibodies of MS sufferers identify and attack specific substances in the myelin, such as the myelin basic protein. Perhaps certain cytokines also play a role. Cytokines are small proteins produced by cells that trigger information.
Amit Bar-Or, M.D., of the Montreal Neurological Institute and team tested the vaccine. It is currently known as BHT-3009 and encodes a full-length human myelin basic protein. 30 patients received the vaccine between 2005 and 2006 – they all had relapsing-remitting MS or secondary progressive MS. Replapsing-remitting MS is when the patient experiences symptomatic periods, and periods of remission. Secondary progressive MS is when the patient’s symptoms gradually get worse and worse, with perhaps some periods of remission.
A placebo or BHT-3009 injection was administered to the randomly selected patients after one, three, five and nine weeks, in doses of 0.5, 1.5 or 3 milligrams. Some were given 80-milligram pills of atorvastatin calcium. At week 13 those who had been on the placebo received four BHT-3009 injections.
The patients also underwent MRI (magnetic resonance imaging) scans at the beginning of the week, and then again after 5, 9, 13, 26, 38 and 50 weeks.
The authors wrote that “BHT-3009 was safe and well tolerated, provided favorable trends on brain MRI and produced beneficial antigen-specific immune changes.” These included a reduction in the number of cytokine-producing CD4+ T cells – a kind of white blood cell. This fall was detected in the cerebrospinal fluid as well as in the blood of three patients who volunteered for a lumbar puncture after completing the course of injections. The scientists say that the atorvastatin does not seem to offer any additional benefit.
The authors wrote “There were no increases in clinical relapses, disability, drug-associated laboratory abnormalities, adverse events or the number and volume of contrast-enhancing [visible on MRI] lesions on brain MRI with BHT-3009 treatment compared with placebo. In fact, there was a trend toward a decrease in the number and volume of contrast-enhancing lesions in the brain in patients treated with BHT-3009 compared with placebo.”
A Phase 2b Trial with 290 patients is underway, using BHT-3009.
If the treatment is successful in MS “antigen-specific DNA vaccines can be developed for prevention or treatment of related diseases, such as type 1 diabetes mellitus, systemic lupus erythematosus, rheumatoid arthritis and myasthenia gravis,” the scientists conclude.
“Induction of Antigen-Specific Tolerance in Multiple Sclerosis After Immunization With DNA Encoding Myelin Basic Protein in a Randomized, Placebo-Controlled Phase 1/2 Trial”
Amit Bar-Or, MD; Timothy Vollmer, MD; Jack Antel, MD; Douglas L. Arnold, MD; Caroline Anita Bodner, MSc; Denise Campagnolo, MD; Jill Gianettoni, BS; Farzaneh Jalili, BSc; Norman Kachuck, MD; Yves Lapierre, MD; Masaaki Niino, MD, PhD; Joel Oger, MD; Mary Price, BS; Susan Rhodes, MS; William H. Robinson, MD, PhD; Fu-Dong Shi, MD, PhD; Paul J. Utz, MD; Frank Valone, MD; Leslie Weiner, MD; Lawrence Steinman, MD; Hideki Garren, MD, PhD
Arch Neurol. 2007;64:(doi:10.1001/archneur.64.10.nct70002).
Written by: Christian Nordqvist