Siponimod is a drug that, since early 2020, has a Europe-wide license to treat secondary progressive MS when it’s ‘active’. Its brand name is Mayzent.
Many people who were first diagnosed with relapsing remitting MS go on to develop secondary progressive MS years later. During this new, progressive stage of MS relapses become less common but a person’s disability carries on getting worse.
Siponimod may be a suitable treatment for some of those people.
Who can take siponimod?
Across the UK you can have siponimod if:
- you've got ‘active secondary progressive MS’. Here ‘active’ means you’re still having relapses or MRI scans of your brain or spinal cord show new or growing lesions
If you’ve been using a wheelchair for over six months, you won’t be offered a disease modifying therapy (DMT) such as siponimod. This is because earlier drug trials seemed to show DMTs make no real difference to your MS if it’s affected your legs this much. New studies are looking at this again.
How does siponimod work?
Your immune system makes special cells that attack and kill viruses and bacteria. In MS these cells attack your nerves by mistake.
Siponimod targets two types of these cells called B and T cells. It traps them in your lymph nodes. This stops them getting into your brain and spinal cord where they would attack the myelin that covers your nerves. This stops inflammation and damage to the nerves.
You take siponimod as a tablet once a day. This is the first drug for secondary progressive MS that comes as a tablet. The only other drug for this type of MS (called beta interferon) must be injected.
How well does siponimod work?
Disability getting worse was slowed down by: 37% compared to placebo
This means that in the trial, on average, people whose secondary progressive MS was ‘active’ saw a 37% drop in the risk of their disability getting worse. This drop was compared to people who took a placebo.
Relapses dropped by: 46% compared to placebo
This means that in a major trial, on average, people whose secondary progressive MS was ‘active’ saw a 46% drop in the number of relapses they had. This was compared to people who took a placebo, a dummy pill with no drug in it.
People who took siponimod also:
- had fewer or smaller lesions on their brain scans
- had less risk of their memory and thinking getting worse. It either stayed the same, or, compared to people who took the placebo, it got worse but did so more slowly
- their brains didn’t shrink as fast. All brains shrink as we get older, but this happens faster in people with MS.
What are the side effects of siponimod?
Compared to other DMTs, the risk of side effects, especially serious ones, doesn’t seem high.
In a major trial siponimod’s most serious side effects were:
- changes to how your heart beats. This includes a short-lived slowing down of your heart, especially when you first start the drug.
- a fall in the number of your white blood cells (lymphocytes). This might put you at more risk of infections. These are usually mild, like colds or urinary tract infections, but could be serious such as shingles.
- macular oedema. This is a swelling in the back of your eye that can affect your sight. One in 50 people in the trial got this
- about one in 50 people had a seizure.
In the trial among the most common side effects (more than one in ten people had them) were:
- high blood pressure
- higher than normal levels of liver enzymes