Managing multiple sclerosis (MS) by therapy may essentially be divided into three areas of focus: treating the acute relapse, managing symptoms and targeting disease pathology. The gold standard for treating a MS exacerbation has remained unchanged over recent years. Generally, most clinicians recommend three to five days of intravenous methyhlprednisolone which may or may not be followed by a course of oral prednisone. The decision to use the addition of oral prednisone is usually dependent on the clinician's preference along with the response of the individual person receiving treatment.
Therapeutic options for managing symptoms of MS have expanded greatly over decades. There is continual research into developing medications aimed at alleviating certain symptoms, obviously not only specific for MS but for which can be used for numerous neurological conditions Theses therapies have allowed people with multiple sclerosis to improve their quality of life. Commonly used medications are oxybutynin for the bladder, gabapentin for neuropathic pain, and modafinil for fatigue to name a few. However, it is important to make sure that one clinician is aware of all of the prescribed medications to assure no contraindications and to manage potential side effects.
The most important breakthrough in MS research in recent years has been the discovery and approval of therapies aimed at targeting disease pathology. Today there are six FDA approved medications for treating MS. There are four medications generally used for first line treatment in relapsing remitting MS. These are the immunomodulatory drugs which aim at altering the immune system in order to reduce lesion formation and ultimately decrease frequency of relapses. Three of the four immunomodulatory drugs are called interferons. Interferons inhibit the synthesis of gamma interferon (which is thought to worsen disease) and alter the autoimmune cascade of events in the central nervous system. The first interferon, interferon beta 1b, was approved in 1993, followed by the approval of interferon beta 1a in 1996 (given by intramuscular injection) and 2002 (given by subcutaneous injection). Glatiramer acetate, which was approved in 1996, works differently than the interferons, by inducing regulatory/suppressor cells that may cross-react with myelin proteins. However each of the four immunomodulatory treatments had similar results in the FDA pivotal trials leading to about a 30% reduction in clinical relapses. These medications are not cures for disease, but may have an impact by reducing disease burden and slowing down progression of disease.
Two other medications have been approved for treating MS, mitoxantrone and natalizumab. Mitoxantrone is an immunosuppressive drug approved for secondary progressive, relapsing progressive and worsening relapsing remitting MS. It is often used in those people with more aggressive disease who may not respond to one of the immunomodulatory treatments. Natalizumab is the newest drug to enter the market for treating MS. It was initially approved by the FDA in 2004 but then suspended due to the development of a neurological disease, progressive multi-focal leukoencephalopathy (PML) in two patients who had participating in the pivotal trials. However, after safety analysis and investigation, natalizumab was reintroduced by the FDA. The pivotal trials indicate that natalizumab significantly reduces relapse rate and disease progression. Natalizumab may be an appropriate and beneficial choice of treatment for some individuals but this should be carefully discussed by the clinician and patient so that an educated decision may be made.
In an online edition of the journal Neurology (published online September 12, 2007), Vellinga and colleagues reported results from one site of the pivotal studies suggesting that natalizumab may have a rebound effect on size and development of lesions on MRI scan after withdrawal of natalizumab. This cohort consists of 21 patients and the data was more pronounced in those patients who had initially received placebo and therefore had only short exposure to natalizumab. This data varies from previously reported data that indicates no rebound effect of stopping natalizumab. Future research should be explored to better understand the clinical significance and possible MRI changes following the withdrawal of natalizumab.
Post marketing data regarding the approved therapies for MS continues to be explored and researched to better understand the efficacy and effects of the current medications. This data allows for clinicians and patients to make educated decisions regarding treatments so that optimal responses may occur.
Published On: October 11, 2007