What we're doing about progressive MS
More and more research is being done into understanding and treating progressive MS – and now there’s real momentum and hope of finding new treatments.
Finding effective treatments for progressive MS is our top research priority and that of the global research community. With new knowledge being gained about how to repair myelin and protect nerves, new projects funded and clinical trials underway, there’s hope on the horizon.
What is progressive MS?
If your MS is progressing, it means some of your nerves are dying. You might experience this as disability getting worse or another symptom that doesn't get better. This damage is permanent.
The speed at which this progression happens varies a lot, and it's not yet possible to predict exactly how it will affect each person.
If you experience visible progression, you probably have a diagnosis of progressive MS. But sometimes progression is hidden and can only be seen on an MRI scan.
Some people who experience progression may also have an active form of MS. This means the protective myelin coating around your nerve cells is being attacked by your immune system. Active MS can be experienced as relapses (where symptoms get temporarily worse) or the activity may only be seen on an MRI scan.
There are two types of progressive MS:
Primary progressive MS affects around 10 to 15% of people with MS. In this type of MS, clear periods when your disability stops or gets a bit better are extremely rare. Instead, your condition begins with mild symptoms that slowly get worse.
Secondary progressive MS follows relapsing MS. You no longer have clear periods when your disability stops or gets better (remissions) and your disability gets steadily worse. In the past, it usually took around 20 years for relapsing MS to change into secondary progressive MS. But thanks to disease modifying therapies (DMTs) this is changing.
- Fewer people are likely to go on to secondary progressive MS
- For those that do, this could take longer to happen.
What causes MS progression?
It's thought the build-up of disability in MS is caused by damage directly to the nerves themselves.
In the early stages of MS, immune cells attack the protective myelin coating around the nerves. Our brains have a system for repairing myelin damage. But as MS progresses, this repair system stops working as well.
We think it’s a combination of factors that causes MS progression, including:
- Myelin-making cells no longer effectively repair damaged myelin
- When myelin is damaged, debris and toxins build up around the nerves, causing an increase in inflammation
- The nerves don't get the energy they need to work properly, because mitochondria - the energy powerhouse of the cells - are also damaged
Over time, this environment causes nerve fibres to die, in a process called neurodegeneration. With the nerve fibres lost, the messages can no longer get though, and can lead to any disability becoming permanent. This gradual, steady accumulation of disability is what we call MS progression.
We’re learning more and more about how damage is caused in progressive MS. And we can use this knowledge to design new treatments.
Latest research into MS progression
Scientists are working on three key areas of research that together they believe can stop MS:
- Preventing the immune damage
- Promoting myelin repair
- Protecting nerves from damage.
1. Preventing immune damage
Current treatments modify the behaviour of immune cells to prevent them from attacking myelin. These are mainly effective for relapsing MS, where immune attacks are more common. But recent clinical trials have found that in early progressive MS, where immune attacks are still causing damage, this type of treatment may be able to slow MS progression.
Ocrelizumab targets a type of immune cell called a B cell, stopping them from attacking myelin. Ocrelizumab is licensed to treat early primary progressive MS. In May 2019, after originally rejecting it, NICE approved the use of ocrelizumab for people with early primary progressive MS on the NHS.
Another drug called siponimod traps immune cells in the lymph nodes, preventing them from crossing into the brain and attacking myelin. In October 2020, siponimod was approved for use on the NHS as the first oral treatment for people with active secondary progressive MS.
For more advanced progressive MS, we don’t expect immunomodulatory drugs to have much effect. This is because the treatments stop immune attacks, and so can only help people experiencing active inflammation. They can’t repair myelin damage or protect nerves. This means they can’t reverse symptoms that are due to progressive nerve loss.
A few trials are now exploring whether drugs that target the immune system are able to slow down the worsening of hand and arm function for people with advanced progressive MS. We're co-funding ChariotMS which is testing whether cladribine, a drug originally developed for cancer, can help people with advanced MS maintain the use of their hands and arms.
2. Myelin repair
In progressive MS, the cells in the brain that can repair and replace damaged myelin stop working as well as they used to. This leads to a build-up of damage in the nerves, which eventually may die.
Finding ways to kick-start the natural process of myelin repair is an important focus of our biomedical research programme. Our researchers are working to understand myelin repair in more detail, why it fails in progressive MS, and to identify targets for drug development.
Every discovery brings new opportunities for us to develop myelin repair treatments. And these could be effective for everyone with MS.
3. Protecting nerves from damage
The progression of disability in MS is not all down to myelin damage. We now know that the nerves themselves stop working properly. If we’re going to stop MS progression, we need to protect the nerves and make them as strong as possible.
Our researchers are looking at a number of different processes in the nerve cells to find out what goes wrong and ways to fix it. If we can find drugs that can protect nerves from damage then we have a real opportunity to stop MS getting worse, and even reverse disability for some people.
What are we doing about MS progression?
Our top priority, as agreed by people affected by MS and health care professionals, is to find effective treatments to slow, stop or reverse the accumulation of disability associated with MS.
We’re supporting research projects across the UK that are tackling all aspects of progressive MS, from myelin repair to finding effective symptom management programmes.
An international effort
We're a member of the Progressive MS Alliance. It’s a network of MS organisations from around the world who have come together to speed up the development of treatments for progressive MS.
By working together, we can achieve more.