HSCT for MS

Read our tips for talking about HSCT with your doctor or nurse

Jump to:

• What is HSCT
• What does HSCT stand for?
• Who can HSCT work for?
• How does HSCT treatment work?
• How well does HSCT work?
• HSCT side effects
• HSCT, pregnancy, breastfeeding and contraception
• Getting HSCT and the MS Society

What is HSCT?

In MS the immune system mistakenly attacks the protective layer around nerves, called myelin. HSCT (haematopoietic stem cell transplantation) is a procedure that aims to reset the faulty immune system to stop this happening. It does this by partly or fully wiping out your immune system and then regrowing it using your own stem cells. These new stem cells can’t regrow damaged nerves in your brain or spinal cord. But they do make your immune system work like it should again.

You ‘ll also see HSCT called AHSCT or aHSCT. This stands for Autologous Hematopoietic Stem Cell Transplantation. ‘Autologous’ means the transplant uses the person’s own cells, not cells from a donor. We use ‘HSCT’ in our information because this is what most people with MS call it and search for online.

What does HSCT stand for?

HSCT stands for ‘haematopoietic stem cell transplantation’. Most cells in the body are very specialised and can be just one type of cell. But stem cells can make different kinds. Haematopoietic stem cells can become any kind of blood cell, including immune cells. HSCT is a medical procedure that removes harmful immune cells and rebuilds the immune system with a transplant of stem cells.

Who can HSCT work for?

Research has shown that HSCT is most effective for people with MS who:

• have frequent relapses and MRI scans showing new or active lesions – these are signs of ‘active inflammation’
• are early on in their disease course
• don't have significant disability - measured by the EDSS (Expanded Disability Status Scale). You need a score of 5.5 or under to get HSCT on the NHS. 

European guidelines are based on these research results. Most centres that carry out HSCT use those guidelines to assess who can have HSCT.

You’re most likely to benefit if you have highly active relapsing MS. That’s because HSCT targets the immune system that causes the inflammation we see in MS. Relapses and new or growing lesions are signs of this inflammation. 

Weighing up the risks and benefits, HSCT is best suited to people who still have relapses despite taking disease modifying therapies (DMTs).

HSCT is used when one of the more effective DMTs can’t control the inflammation. They’re not  stopping relapses or preventing new lesions. The drugs in question are alemtuzumab (Lemtrada), ocrelizumab (Ocrevus), ofatumumab (Kesimpta), natalizumab (Tysabri and Tyruko) and cladribine (Mavenclad). 

Some people qualify to have HSCT if they have signs on their MRI scans of inflammation but aren’t getting symptoms of a relapse.

You can also have HSCT if you’ve never had a DMT but your MS is very aggressive. This means your MS is getting worse very quickly, with two or more relapses in the last year. 

HSCT and progressive MS 

HSCT might also be able to help a few people who have progressive MS and whose disability is getting worse very quickly. But they must have high levels of active inflammation. This means they still have relapses or MRI scans show new or growing lesions.

HSCT is unlikely to help progressive MS without relapses or signs of inflammation on MRI scans. Researchers are working hard to find effective treatments for people with progressive MS.

Find out more about who can get HSCT

Read about our plan to stop MS

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How does HSCT treatment work?

HSCT aims to 'reset' your immune system so that it stops attacking nerves in your brain and spinal cord. It does this using a type of stem cell that’s made in your bone marrow. These are your haematopoietic stem cells. 

These stem cells can make all the different cells in your blood, including immune cells. But they can't regenerate damaged nerves or other parts of the brain and spinal cord. 

At the start of HSCT treatment you take drugs that encourage the stem cells to move out of your bone marrow and into your blood. The stem cells are collected from your blood and stored to be used later. Then you take chemotherapy drugs. This wipes out the faulty immune cells that are causing your MS. 

The stem cells collected earlier are then put back into your body where they rebuild your immune system.

Myeloablative and non-myeloablative HSCT

There’s more than one type of HSCT. They wipe out the immune system by different amounts to ‘reset’ it. One type is called ‘myeloablative’, which fully wipes out the immune system. Another is called ‘non-myeloablative’, which partly wipes it out. In the UK, non-myeloablative HSCT is used to treat MS.

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How well does HSCT work?

HSCT is seen as one of the disease modifying therapies (DMTs). All DMTs can be put into three groups based on how well they control MS. HSCT is classed as 'high', the best of the three groups. This is based on how much it reduces relapses and slows down the rate at which people's disability gets worse. 

HSCT can’t undo all the damage MS has already done. But some people do see some improvement in their symptoms and disability. This happens because HSCT has stopped the  inflammation. That gives the body more chance to repair the myelin covering around nerves. But HSCT can’t rebuild nerves that no longer work.

Relapsing MS

Clinical trials have shown that HSCT is able to reduce relapses – mainly for people with relapsing MS. For some people their symptoms stabilise or get better, or their disability improves. But these improvements don’t always last.

A randomised control trial looked at 110 people with ‘very active’ relapsing MS. Half of them were treated with non-myeloablative autologous HSCT and the other half with other DMTs. These other DMTs included some of the less effective drugs. Non-myeloablative autologous HSCT is the kind of HSCT used to treat MS in the UK. The results showed:

• 99% of the people treated with HSCT had no relapses for 1 year. Only 1 person who had HSCT suffered a relapse. There were 39 relapses in people taking drug treatments
• 94% of people treated with HSCT didn’t see their disability get worse for 3 years (compared to 40% of those on drug treatments)
• EDSS scores (which measure disability) improved for the people treated with HSCT. For those on drug treatments, average EDSS scores got worse

Read about more recent HSCT trials

Progressive MS

For progressive MS, we’ve seen some encouraging results for people treated early on in their condition, and where there’s still signs of inflammation (on an MRI scan, or in the shape of relapses).

Unfortunately, HSCT hasn’t worked as well for people with progressive MS who no longer show signs of inflammation and who have high levels of disability.

Read more about HSCT research studies

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HSCT side effects

Compared to other DMTs, HSCT has among the highest risk of side effects, especially serious ones.

HSCT side effects include:

• risk of infections in the early stages of HSCT. Also, increased risk of developing infections in the long term
• an increased risk of developing cancer and autoimmune conditions, such as thyroiditis
• early menopause
• fertility problems
• in rare cases death

Chemotherapy - part of the HSCT procedure - has its own side effects too. These include an increased risk of bleeding and bruising, fatigue, loss of appetite and hair loss.

If someone has a high level of disability before the transplant, chemotherapy can also do more harm than good. Chemotherapy treatments can lead to your mobility getting worse and a worsening in how your nerves work.

The side effects of chemotherapy are more likely to be serious if you have the more intense type of HSCT – myeloablative, where the immune system is completely wiped out.

Some people have died as a result of HSCT. Since 2005, 1 person in about every 330 who had HSCT for MS has died because of it. The death rate has gone down as doctors have gained more experience with HSCT. The risk can be higher for people who are older, have a higher EDSS score, or have certain other conditions. A centre that offers HSCT should be able to explain your own risk, which will depend on lots of things, like your age and overall health. 

Compared to the hardest-hitting MS drugs, HSCT is a much more aggressive treatment. It’s  harder on the body and means significant time in hospital. It comes with a chance of very serious, complications that might be fatal for a very small number of people.

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HSCT and pregnancy, breastfeeding and contraception

Pregnancy

If you’re able to get pregnant, your medical team will give you advice before you have HSCT.

The chemotherapy drugs that you take with HSCT can harm an unborn baby and damage ovaries and testicles. This damage is often permanent, leaving you unable to have children (infertile). It can also cause an early menopause for women. Hormone replacement therapy (HRT) can help with menopause symptoms but it can’t stop the infertility.

Before you have HSCT, it’s possible to collect and freeze your eggs or sperm. You can then use them later to have children using procedures like IVF (in vitro fertilisation).

Your medical team will advise how soon after HSCT it’s safe to try to have a child.

Breastfeeding

High levels of chemotherapy drugs can get into breast milk. So breastfeeding must be avoided during HSCT. Your medical team will advise how soon after HSCT it’s safe to breastfeed.

Contraception

If you have periods, these can stop during chemotherapy, but you might still be producing eggs so you could still get pregnant.

Because chemotherapy drugs could harm an unborn baby, you should keep using reliable contraception. It takes about 6 to 12 months for periods to go back to normal. It’s important that you use contraception during this time. Your doctor should discuss all this with you.

Because chemotherapy damages sperm, men should get advice from their medical team about what type of contraception they should use.

Getting HSCT and the MS Society

We’re working alongside clinicians to help make sure people with MS can get treatments that are right for them at the right time. This includes HSCT for people that are eligible.

Read more about what we're doing for HSCT

Read Miles' HSCT story

StarMS clinical trial

Right now, the StarMS clinical trial is comparing HSCT with four other highly effective DMTs. These are ocrelizumab (Ocrevus), alemtuzumab (Lemtrada), cladribine (Mayzent), and ofatumumab (Kesimpta).

The trial team have completed recruitment, so aren't looking for people to take part. Everyone stays part of the trial for two years, so we should hear the results by 2027.

Find out about taking part in other research studies

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