Saturday, September 16, 2006

Studies probe new MS treatments

By Rocky Wilson


Research is under way to come up with new drugs to treat multiple sclerosis, of which the Inland Northwest has one of the highest incidence rates in the world, say medical professionals here who specialize in the disease.

Already, inroads have been made in combating symptoms and in slowing the frequency of relapses of the disease, which flares up and subsides without warning, says Dr. Roy Kanter, medical director at the Holy Family Multiple Sclerosis Center, at the North Side medical center.

�Thirteen years ago we had no treatments at all for MS,� says Kanter.

Since then, five drugs for treatment of MS victims have been approved by the U.S. Food and Drug Administration. Last month, the FDA allowed one of the five drugs to be put back on the market. The controversial medication, Tysabri, is believed by Kanter and others to have great potential to increase the time between MS relapses.

Also, the New York City-based National Multiple Sclerosis Society (NMSS) says another about 140 drugs to treat MS are in various stages of clinical testing around the world and studies also are being done on nondrug compounds to address symptoms of the disease.

Sara Bernstein, a science writer for the organization who takes calls from the press for NMSS, says those studies involve drugs to treat both relapsing-remitting MS and the more severe progressive MS, for which no FDA-approved medications currently are available.

Dr. Steven Pugh, director of the Center for Multiple Sclerosis at Rockwood Clinic, says about 60 percent of MS victims have relapsing-remitting MS, in which symptoms arise and then abate, with the cycle repeating itself periodically as the disease slowly takes its toll over a number of years. The other 40 percent is split evenly between those with the more serious progressive form, in which the disease commonly attacks the spinal cord and progresses quickly, and the benign form of the disease, in which fatigue is the main symptom, says Pugh.

Between 1993 and 2001, the FDA approved four MS drugs, BetaSeron, Copaxone, Avonex, and Rebif, all designed to combat immune cells that somehow invade the central nervous system in MS patients and attack nerve cells there, says Dr. Timothy Coetzee, director of research initiatives for the NMSS. He says those drugs have helped cut back on the immune system�s attacks on the brain or spinal cord of MS patients, allowing the time between MS relapses to be extended.

�These drugs either stop or slow the progression of the disease,� says Robert Hansen, director of the Spokane-based Inland Northwest chapter of the National Multiple Sclerosis Society. �They give the patient hope and can hopefully stabilize that person until the cure comes along.�

The number of people diagnosed with MS, especially in the U.S., where access to an individual�s health records is protected by law, is at best a guess. Hansen says about 1,100 MS victims in Spokane County have registered with that nonprofit group, and in the 35-county region his office serves, about 2,300 MS victims have registered.

�We believe the actual number is higher than that,� Hansen says. He says NMSS urges everyone with MS to use at lease one of the five disease-modifying drugs on the market now.

Between them, the Holy Family and Rockwood MS centers provide service to a total of about 1,200 patients.

MS has no cure and its cause is unknown, says Kanter. It occurs when a person�s immune system attacks the myelin sheath surrounding nerve cells, often leading to a loss of motor control or even paralysis. The disease, which can attack any part of the central nervous system, commonly begins with episodes of fatigue, intolerance to heat, double vision, and other symptoms that last weeks or months. It can debilitate sufferers, but rarely kills them. In most cases, sufferers improve slowly until they�re largely free of symptoms, but there�s usually some residual damage to the body, and within weeks, months, or even years the symptoms return, he says.

Pugh believes that when MS is diagnosed, it�s common for more than one disease mechanism to be at work, meaning that there�s more going on at the cellular level that can�t be seen with magnetic resonance imaging scans and isolated with blood tests. He says symptoms are quite different from patient to patient and that the study of genetic defects and genetic codes might explain some of those differences.

�There are currently very few, if any, patient trials under way to look at treatments to repair a damaged brain and spinal cord that is the result of years of damage from MS,� he says. �Most experts believe that the treatment for the chronic damage in MS lies in stem cell research. The inability to progress rapidly with stem cell research is the major roadblock to this type of research.�

MS studies

Three of the more promising clinical studies involve drugs that already have been approved for other uses. Those drugs either attack or regulate one or both of a pair of prominent types of white blood cells, B cells and T cells, that enter the central nervous system of MS victims and do damage. Those B and T cells are common in the human body, says Coetzee.

�In the average person, B cells and T cells are never in the brain or the spinal cord,� says Coetzee. �But in MS patients those cells break through protective barriers in the central nervous system and attack the myelin covers of nerve cells there.� Why that happens is unknown, he says.

Coetzee says B cells in MS patients act differently than B cells in other humans by creating an antibody that attacks myelin cells in the brain and spinal cord. He says Rituxan, which the FDA has approved for treatment of lymphoma as well as some types of arthritis, is a known killer of B cells. He says the MS Rituxan study is aimed at wiping out B cells in hopes of reducing the frequency of MS attacks and reducing the number of MS-caused lesions on the brain.

He says the body will replace B cells destroyed by Rituxan, and there�s hope that those new B cells will no longer produce the damaging antibody. Separate Rituxan studies are testing treatments for people with primary progressive MS and those with relapsing-remitting MS, Coetzee says.

In another trial, Lipitor, a widely used cholesterol-lowering drug, is being studied for its effect on T cells. Coetzee explains there are a family of T cells, one of which, called a T-cell helper, slows other T cells� attack on the myelin sheath of nerve cells. Coetzee says Lipitor is being studied as an agent that �stimulates production of regulatory T-helper cells.�

The Lipitor study primarily directed at individuals who�re experiencing the earliest stages of the disease, is �very promising,� Coetzee says.

Cladribine, a chemotherapy treatment for some forms of leukemia, also is being studied for possible use in MS patients. That drug destroys both T cells and B cells, thus reducing the number of immune cells that can damage nerve cells in the central nervous system, Coetzee says. It�s hoped the trial will show that the drug will give relapsing-remitting patients �a longer window between attacks,� he says. The long-range effects of clabridine treatment for MS patients are still under study.

The NMSS says non-drug clinical studies geared toward treating MS symptoms include the use of ginseng to help improve cognitive functions and lessen fatigue, stress management to control MS inflammatory activity, and consumption of fish oil to address depression associated with MS.

Tysabri

Tysabri was yanked from the market early last year, just four months after it was introduced, because of potential lethal side effects.

�Tysabri attaches itself to the white blood cells that are primed to attack the myelin covering of the nerve cells. It blocks this attack by never letting them get into the brain,� Kanter says.

Yet, there are risks with Tysabri. Pugh says that during the four months it was on the market, at least one person taking the new drug died after contracting a rare infection that can occur when the immune system is compromised.

He says that Biogen Idec Inc., the Cambridge, Mass.-based company that manufactures Tysabri, had spent more than $1 billion researching the safety of the drug, but pulled it off the market before the FDA ordered it to do so. More tests and studies were conducted, and in July the FDA again approved Tysabri for patient use.

�The benefits of having it available as a drug exceed the risk,� Kanter asserts.

Pugh says, �It�s a very effective medication for the right patients,� adding that patients who experience frequent relapses when they�re first diagnosed with MS are ideal candidates for the drug. He says tests haven�t been done with the drug yet on patients who are in the advanced stages of MS, which can include paralysis, loss of vision, diminished mental capacities, and incontinence, because there�s little hope that Tysabri can undo that damage.

Hansen says, �Tysabri offers neurologists another tool to work with to slow the progression of the disease. We�re excited that there�s another tool, but we�ll leave it up to the doctors to decide who needs to get treated.�

Prolonged buildup

Kanter says, �With the usual progression of the disease, the vast majority of people diagnosed with MS will have problems that build up over years, and many require canes and walkers within 15 to 20 years after their diagnosis.�

He says MS strikes three times more women than men, often first appears when its victims are between the ages of 25 and 40, and people living in Spokane are three times more likely to contract the disease than residents of warm climates.

The disease most commonly strikes individuals of Northern-European ancestry who live north of the 40th parallel, says Kanter. According to Hansen, 95 percent of the Inland Northwest�s population is of Northern European descent. Spokane, of course, is well north of the 40th parallel, which, in the western U.S., stretches roughly from Denver to San Francisco.

Kanter feels an added factor behind the high MS rate here is that Spokane has a �highly informed population� that knows about MS, and people here recognize the disease and report it sooner than residents of other areas.

Eighty percent of MS patients suffer from clinical depression at some point when they have the disease. Kanter says depression is more prevalent among sufferers of MS than among people who are diagnosed with terminal diseases. Hansen attributes the frequency of depression among MS victims to the ongoing uncertainty and grieving associated with the disease. Also, he says, MS patients often experience some loss of brain tissue.

In addition to the possibility of no longer being able to work, MS patients must contend with the high cost of drugs to treat the disease. The four most common MS drugs�BetaSeron, Copaxone, Avonex, and Rebif�cost between $1,500 and $1,800 a month, while Tysabri can cost up to $4,000 a month, says Kanter.

The good news is that pharmaceutical companies usually have programs to help defray such expenses, typically based on patients� taxable income for the previous year, says Pugh. He�s never heard of a case in which a drug company didn�t help a patient who needed assistance to meet the cost.

Contact Rocky Wilson at (509) 344-1264 or via e-mail at rockyw@spokanejournal.com.
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