Another drug for the treatment of multiple sclerosis has been approved by the Food and Drug Administration (FDA) this past week, and it has the effect of slowing the progress of the disease. Biogen Iden, INC., whose headquarters are in Cambridge, Masschusettes, now has a longer acting drug called Plegridy, which eventually will replace their current and popular pharmaceutical Avonex. European approval for Plegridy was obtained by Biogen in July of this year.
Both drugs are injected into the body, Avonex, intramuscularly (into a muscle), while Plegridy is injected subcutaneously (under the skin). This type of injection uses a smaller needle. Both of these drugs are called interferons, which is a protein that communicates between cells to trigger defense mechanisms in the immune system. Plegridy only needs to be injected once every two weeks, However Avonex is injected on a weekly basis.
Avonex is a popular method of treatment, and Biogen plans to support this interferon drug into the future, as many patients are familiar with using it and do not want to switch. This particular drug has had tremendous sales for the first portion of this year, $1.5 billion, world-wide. As Plegridy takes hold, those sales will diminish, plus the fact that oral treatments are increasing in popularity, and that includes Biogen’s own Tecifidera, a drug approved for use in 2013.
Drugs like Plegridy are used to reduce the advance of multiple sclerosis and slow its activity, which is the loss of the physical ability to use one’s muscles, visual functions and motor coordination. This disease assaults a person’s central nervous system; the brain, optic nerves and the spinal cord. Plegridy has been developed to combat these problems in patients with a relapsing form of MS. Some of the reactions to Plegridy include joint pain, weakness, chills injection site pain, headache, fever, muscle pain and flu-like illness.
With the introduction of the drug Plegridy, the progression of this inflammatory disease may slow down to a crawl. The main onslaught of MS is against a person’s immune system. The nerve fibers in the body are enclosed by myelin, a protective covering similar to plastic coatings over electrical wiring. It facilitates the flow of electrical signals along the nervous system to the brain. When a person acquires MS, myelin disappears in diverse areas and scars the area, hence the term sclerosis. Because this activity occurs in many different areas, the term multiple comes into play – leading to the name Multiple Sclerosis.
Areas where there is no or very little myelin are called lesions or plaques. Nerve fiber breaks or is seriously damaged as the lesions become more severe. The electrical pulses no longer flow evenly along nerve fibers to their intended destination. If there is no myelin at all the nerve fibers are unable to conduct electrical signals for the brain to actuate instructions and carry out an action; to make leg muscles move for walking, or some other activity. A person with MS can think about an action, but the muscles will not perform the action.
The disease does not discriminate among humans, any one of any age may be impacted by it. Those who most commonly acquire MS are between the ages of 20 and 50. It does affect more women than men though. Persons of European ancestry may be more predisposed to develop it than people of other ethnicity. However anyone may get it.
There is no definite factor that causes MS, though it is believed by experts that a person’s immune system assaults myelin, in a similar way it attacks foreign bodies, like a bacteria or a virus. The most prominent theory is a genetic cause. Someone may be predisposed to developing it due to another person in the family who had it, such as a parent, a grandparent or a sibling. Scientists have a theory that some set of gene alteration people are born with, and exposure to certain environmental cause might affect the immune system in a way that leads to MS.
Environment plays a major role in those who develop multiple sclerosis. For example, in Europe, people from northern countries are more likely to have MS than those from Southern Europe. The same holds true for America.
However, in the U.S. Caucasians are at a higher risk for multiple sclerosis than any other racial groups in the United States; despite geographical location. Slowing the progression of MS using a more powerful drug is a great advance for those suffering with this issue and a muted relief for families with members who have this condition.
By Andy Towle