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Lab researcher

How relevant is available research evidence to my MS?

DMDs are still fairly new treatments. Although their use in the USA dates back to the early 1990s, the first beta interferon drug was licensed in the UK as recently as 1995. Glatiramer acetate, was licensed in the UK in 2000.

Because the drugs are relatively new, there is still a great deal to be learned about their benefits and risks. Research is still in its early stages and our understanding of treatments is mainly based upon studies of people who have received treatment for 2-4 years only. We do not know about the benefits to patients who may take these drugs for long periods of time such as 10 years or more.

Any benefits of DMDs reported by research can also not be guaranteed for individual patients: Drugs do not benefit everyone who is eligible for treatment and even if there is a positive effect the amount of this can vary. Some people have a better experience than others and there is no way to predict who will find the treatment very helpful and who may find that it has little or no effect on them. The results of studies show the average effect that the drug has had on all the people taking part - it does not mean that this effect occurs in every patient.

 

What research evidence is reported on this website?

Many research studies have been conducted to look at the benefits of the different licensed DMDs. However, comparing the findings of these studies with each other can be extremely difficult. This is because of differences in the way these studies were designed and conducted. For example, they have not all studied similar patients, and different measures of the benefits of treatment have been used. For more information about Research studies, use the link at the bottom of the page to go the supplementary section.

The information below is therefore based on the conclusions of important groups who have brought together experts to review the evidence. These have taken into account the major published studies. These groups are:

For more information, use the link at the bottom of the page to go to the 'Further Reading' pages.

 

How have the studies assessed the benefit of treatment?

There are two major benefits that studies consider when assessing the effectiveness of treatments:

a) The number of relapses experienced - whether receiving therapy reduces how often relapses occur

b) The rate of disease progression - whether receiving DMDs slows how quickly people become disabled by MS



What are the reported short term benefits of DMDs?


a) The number of relapses experienced.
Beta interferons (Avonex®, Rebif® and Betaferon®) and Glatiramer acetate (Copaxone®)

All four licensed drugs have been shown to reduce the rate of relapse in patients with relapsing remitting MS by about 30% (just under one-third); in an average patient, if you've had just one relapse, you have about a 50 percent chance of having another one over the next two to three years. But if take beta interferon, you have only a 35 percent chance of another relapse. This reduction has been demonstrated for the first 2 years of therapy.

The beta interferon products have also been shown to reduce relapse frequency and severity in secondary progressive MS.

Benefit 1: Avonex®, Rebif® Betaferon® and Copaxone® each reduce the number of relapses by approximately one-third in the short term.


b) The rate of development of disability
Beta interferons (Avonex®, Rebif® and Betaferon®)

The major trials of beta interferons have found that using them slows the development of disability in MS, although there is still debate about how much this happens. Looking at all the major trials together, the Cochrane review (Cochrane Rice 2004) found that beta interferons slow the development of disability by about 31% in people who stayed on treatment for 2 years. However, some doubt exists over how accurate this result is because some people dropped out of the studies before the end of two years, and we don't know how their disability changed.
 

The National Institute for Clinical Excellence found that open label studies (i.e. studies where the patient and the medical team knew which drug the patient was taking) suggested that beta interferons continue to have a positive effect beyond 2 years. For people who have taken the drug in studies for approximately 4 years, disease activity appears to be lower than might otherwise be expected.

Glatiramer acetate (Copaxone ®)

Whether Glatiramer acetate has an effect on the development of disability is still unclear. As a result of this, the product licence for the drug in the UK does not cover this outcome.

The Cochrane review (Cochrane Munari 2004) concluded from its review of the research that glatiramer acetate did not show any significant effect on disability increase, measured as a sustained worsening on the EDSS.


Benefit 2: Avonex®, Rebif® and Betaferon® each slow the rate of development of disability in the short term (2 years), although it is not yet clear how large this effect is.



What are the long term benefits (beyond 2 years) of DMDs?

The long-term impact of both the interferon treatments and glatiramer acetate is still unknown.

As more patients in the UK and in other countries remain on treatment over a number of years, it will be possible for researchers to make an assessment of this, although it will take some time to find out for sure because the course of MS is so variable.

What other issues should I be aware of?


a) Benefits of DMDs shown by magnetic resonance imaging (MRI scanning)
Frequent MRI scanning is a technique that is used to visualise and measure the activity of MS in the brain more accurately. Most studies use MRI to provide additional information about the effects of DMDs on MS - it has been helpful because it is very sensitive in detecting new MS lesions when they occur. A beneficial effect of a treatment on disease activity as measured by MRI is not sufficient for a DMD to be licensed. Although changes as measured on MRI correlate partly with clinical attacks, they do not correlate well with the development of disability. Therefore, many experts recommend that MRI scanning should not be used on its own to assess the effectiveness of a particular drug and MRI scanning should not be used as a measure of MS disease activity in routine clinical practice. It is recommended that treatment decisions should be instead be based on clinical factors (NICE 2002, Cochrane Munari 2004, Cochrane Rice 2004)

 
b) Neutralising antibodies
Over time, the human immune system may react to treatment with interferons. This can lead to the production by your body of antibodies. There is evidence that these antibodies reduce the effectiveness of the DMDs in preventing relapses. These antibodies develop in about 30% of people on Betaferon, 25% on Rebif and 5% on Avonex. At present there is debate amongst experts around how important neutralising antibodies are. This is due to several factors:
Further research is needed to find out how best to carry out and use the results of antibody testing with people on DMDs. At present antibody measurements are not used routinely to monitor treatment.

c) The treatments won't reverse symptoms that have become permanent before starting treatment.

The DMDs are intended to reduce the chances of having new problems from MS in the future, especially to reduce the relapse rate by about 30%. They do not reverse the effects and symptoms of MS that have developed and become permanent before the treatment is started.

Other web sites to visit are listed in the 'Further Reading' section.

To get back to this page, use the 'Return' link that will appear under the left hand menu.

Also, see the supplementary page on Research Studies for more detailed information.