Siponimod (Mayzent)

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• Who can take siponimod (Mayzent)?
• How does siponimod (Mayzent) work?
• How well does siponimod (Mayzent) work?
• Siponimod (Mayzent) side effects
• Stopping siponimod (Mayzent)
• What tests do you need with siponimod (Mayzent)?
• Siponimod (Mayzent) and pregnancy, breastfeeding and contraception

Who can take siponimod (Mayzent)?

You can have siponimod (Mayzent) if you have active secondary progressive MS (SPMS). 

Across the UK active secondary progressive MS means: 

• you’ve had at least one relapse in the last year (Scotland) or two years (elsewhere)

or

• you have new, active or growing lesions on your MRI scans

In May 2022, in England and Wales another set of people were added to this list. You can now switch to siponimod (Mayzent) if you’re already on a DMT but your symptoms or disability are still getting worse. In these cases you don't need to wait for a relapse. You don’t need new, active or growing lesions on your MRI scans.

In Scotland and Northern Ireland you still need relapses or new,active or growing lesions to get siponimod. 

You’re unlikely to get siponimod if you’ve been using a wheelchair for over six months. Earlier drug trials seemed to show DMTs make no real difference if MS has affected people’s legs this much. New studies are looking again at how DMTs might help people who use wheelchairs.

You can’t take this drug if you have an allergy to soya or peanuts. That’s because of an ingredient in the tablets.

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How does siponimod (Mayzent) work?

Siponimod (Mayzent) works by targetting B and T cells. These are special types of white blood cells that are part of your immune system. They kill viruses and bacteria. But in MS these cells attack and damage myelin. That’s the protective covering around nerves in your brain and spinal cord.

Siponimod (Mayzent) is in the group of drugs called ‘sphingosine-1-phosphate (S1P) receptor modulators’. Any DMT that ends with ‘mod’ is one of these drugs. 

These drugs stick to the surface of B and T cells. This stops many of them leaving your lymph nodes, where they’re made. Fewer of them can get into your bloodstream6, then into your brain and spinal cord. That means they can’t attack myelin around the nerves there and cause lesions and relapses.

You take this drug as a tablet once a day. Siponimod slows down your heart, so everyone starts on a low dose. This lowers the risk of heart-related side effects. You reach the full dose on day six of your treatment.

How well does siponimod (Mayzent) work?

The effectiveness of siponimod (Mayzent) is classed as 'good'.  Each DMT can be rated as ‘moderate’, ‘good’ or ‘high’. This is based on how much it can reduce relapses and slow down disability getting worse. 

Siponimod got the go-ahead in 2020 for use on the NHS based on a trial called EXPAND. In this trial they compared siponimod with a placebo, a dummy treatment with no drug in it. 

Over the three years of the trial siponimod (Mayzent) was a lot better than the placebo at two things. The first was slowing down how fast people’s disability got worse. The second was lowering how many relapses people got.

Disability getting worse was slowed down by: 37% compared to placebo

This means that after the three year long EXPAND trial, on average, people saw a 37% drop in the risk of their disability getting worse. This drop was compared to people who took the placebo. 

This slow down in disability could delay someone’s need for a wheelchair by over four years. 

Relapses dropped by: 46% compared to placebo

This means that in the EXPAND trial, on average, people with active secondary progressive MS saw a 46% drop in the number of relapses they had. This was compared to people who took the placebo.

People who took siponimod also:

• had fewer or smaller lesions on their brain scans
• had less risk of their memory and thinking getting worse. Some people saw their memory and thinking stay the same, for others it got better
• their brains didn’t shrink as fast. All brains shrink as we get older, but this happens faster in people with MS. Brain shrinkage in MS is linked to poorer memory and thinking

How well does siponimod (Mayzent) work over many years?

Siponimod continues to work well over several years. After the original three year EXPAND trial of siponimod (Mayzent) ended, it followed these people for another five years. Siponimod kept working as well as it did during the first three years of the trial. There were no new side effects that doctors hadn’t seen already. People got better results if they started siponimod sooner rather than later. 

Siponimod (Mayzent) side effects

Compared to other DMTs, the risk of side effects with siponimod (Mayzent) doesn’t seem high, especially serious ones. 

Siponimod (Mayzent) causes a fall in your white blood cells (your T and B cells). These cells fight off infections. This might put you at more risk of mild infections like colds. But these could be serious ones like shingles.

Very common side effects (more than 1 in 10 people get them): 

• headache
• high blood pressure
• a blood test shows higher levels of liver enzymes. This means your liver isn’t working like it should 

Common side effects (up to 1 in 10 people get them): 

• shingles (herpes zoster). This is a painful skin rash caused by the chickenpox virus. In the EXPAND trial one in 40 people (2.5%) got this. If you’ve never had chickenpox, you’ll have a vaccination against this virus
• a type of skin cancer called basal cell carcinoma. One in a hundred people got this in the five year extension of the EXPAND trial. This is usually easy to treat. It rarely spreads to other parts of the body. Because of this risk, you should limit how long you’re in the sun. When you’re in the sun, you should cover up and use high factor sunscreen
• a drop in T and B cells (lymphopenia). Symptoms can include fever, sore throat or mouth ulcers
• seizures. Having a fit happened to one in 50 people in the EXPAND trial
• macular oedema. This is build-up of fluid in the eye can cause blurred vision or sight loss if left untreated. In the EXPAND trial around one in 50 people got this. These symptoms go away if you stop taking siponimod
• changes to your heartbeat. This includes a short-lived slowing down of your heart. This is more likely when you first start the drug
• new moles on your skin
• dizziness
• tremor (when you can’t stop a part of your body from shaking)
• diarrhoea
• feeling sick (nausea)
• pain in your hands or feet
• swollen hands, ankles, legs or feet
• weakness
• breathing issues caused by your lungs working less well

Uncommon side effects (up to 1 in 100 people get them): 

• two more serious types of skin cancer. These are melanoma and squamous cell carcinoma. They’re more likely to spread than basal cell carcinoma. Both must be treated early

Find out more about all the possible side effects of siponimod (Mayzent)

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Stopping siponimod (Mayzent)

You should never stop taking a DMT without telling your neurologist. If you suddenly stop siponimod (Mayzent), this could cause a serious but rare complication. It’s called IRIS (immune reconstitution inflammatory syndrome). This can make your MS worse.  

If you can get pregnant, you must keep using contraception for 10 days after your final dose. 

What tests do you need with siponimod (Mayzent)?

Tests before treatment begins

Blood tests will check if:

• you have enough white blood cells
• you have certain infections that mean you can’t take siponimod
• your liver is working like it should
• your body can easily break down this drug. If not, you might need a lower dose. Some people won’t be able to take this drug at all

Before you can take siponimod, as a rule you need an MRI scan to show your MS is active (with new, active or growing lesions). In England and Wales you might not need an MRI in some cases. 

Your neurologist can compare past and future MRI scans to see what difference the drug is making. 

You might need an eye test if you have diabetes or ever had uveitis (a type of eye inflammation). This checks for the side effect of macular oedema. 

At the start of your treatment your neurologist should check your skin. This is because siponimod (Mayzent) can increase skin cancer risk. These are often not the dangerous kinds, but in some cases can be. 

This drug isn’t safe to take during pregnancy. So if pregnancy is possible for you, you need a test that shows you’re not pregnant before you take your first dose. 

If you have certain heart conditions, you’ll have an electrocardiogram (ECG). This will check if it’s safe for you to take siponimod.

Vaccination

Like most DMTs, this drug makes infections more likely. Before you start it, your neurologist will check if you have protection against some of the infections it puts you at risk of. 

Your neurologist will check you’re up to date on your vaccines. This includes childhood ones like chickenpox (that vaccine protects you against shingles) and the MMR vaccine for measles, mumps and rubella. Some ‘live’ vaccines, like these two, aren’t safe to have once you’ve started many DMTs. Your MS team or GP can tell you whether a vaccine is ‘live’ or not. 

You’ll have any vaccines you need a few weeks before you start this drug. 

You can safely have the annual flu jab while taking this DMT. 

Read more about vaccines

Tests during treatment

Blood tests will keep checking your levels of white blood cells (your T and B cells). They’ll check that your liver is working well. You might have regular checks of your blood pressure.

Your neurologist might want you to have an MRI scan once a year to see if the drug is working. But how often you have scans depends on what your neurologist thinks you need. If your MS seems stable, you might have scans less often.

About three to four months into your treatment, it’s recommended that an eye specialist checks you for macular oedema. You might need regular eye checks if your risk of this is higher.

Your doctor should look at your skin from time to time. That way they can spot skin changes early on that might be cancer.

Siponimod (Mayzent) and pregnancy, breastfeeding and contraception

Pregnancy

We don’t have research on whether siponimod (Mayzent) can harm unborn babies. But we know it can cause this kind of damage in animals. If you can get pregnant, you must use contraception to avoid this happening. You need a negative pregnancy test result before you can start this drug. 

If you want to have a child, discuss this with your neurologist or MS nurse. If you think you’ve become pregnant, let your medical team know at once. Never stop your DMT without first getting their advice.

Breastfeeding

Studies in animals show siponimod (Mayzent) can get into breast milk. So you shouldn’t feed your baby this way while on this drug.

Contraception

To avoid getting pregnant, you should use reliable contraception while on siponimod (Mayzent). This means the ‘pill’, condoms, an implant, coil or injection.

If you stop taking this drug, you must keep using contraception for 10 days after your final dose. This is how long the drug takes to leave your body.

Read more about pregnancy, breastfeeding and contraception and DMTs

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