Mavenclad (cladribine)

Mavenclad (cladribine) is a disease modifying drug (DMD) for very active relapsing remitting MS.

You take Mavenclad as a pill in two treatment courses, twelve months apart to reduce the number and severity of relapses. It reduces the number of relapses by about half (50%).

Side effects can include a reduced white blood cell count (lymphopenia) and herpes (oral herpes and shingles).

What is Mavenclad used for in MS?

Mavenclad is a disease modifying drug (DMD) for very active relapsing remitting MS. You have fewer relapses than you might have had with no treatment. Any relapses you do have should be less severe.

Mavenclad is a more effective (category 1.2) DMD; in clinical trials, people taking Mavenclad had about 58% fewer relapses than people taking placebo. In clinical trials, MRI scans showed that people taking Mavenclad had fewer, smaller or no new areas of active MS (lesions). Mavenclad may also slow down the build-up of disability due to MS.

Who can take Mavenclad?

Mavenclad has been available across the UK since 2017. In England, Wales and Northern Ireland, Mavenclad can be prescribed if your MS remains active while taking another DMD or if you have very active MS. This means that you have had two or more disabling relapses in one year and MRI evidence of new areas of MS activity.

In Scotland, the Scottish Medicines Consortium (SMC) has recommended that Mavenclad can be prescribed if you have rapidly evolving severe relapsing remitting MS (at least two relapses in the previous year and MRI evidence of MS activity); or you have relapsing remitting MS that has responded inadequately to treatment with another disease modifying drug (at least one relapse in the previous year and MRI evidence of MS activity).

Mavenclad can only be prescribed by a neurologist with expertise in treating MS. During the pandemic, the requirement for a recent MRI to confirm evidence of MS activity has been lifted.


It's important that you tell your MS team if you have any health problems or are taking other medicines. Mavenclad may not be appropriate if you have existing medical conditions including liver or kidney problems, active cancer, serious infections such as HIV, hepatitis or tuberculosis or are taking other medicines which suppress the immune system (including methotrexate, ciclosporin, cyclophosphamide and azathioprine).

Conception and pregnancy

You must not become pregnant while taking Mavenclad. In men, Mavenclad could affect the development and quality of your sperm for up to six months after treatment, and in women it could seriously harm your developing baby.

Both men and women should use effective contraception for six months after taking Mavenclad to prevent pregnancy. If you or your partner become pregnant within six months of your taking Mavenclad contact your neurologist or MS nurse as soon as possible.

If you become pregnant after six months of your first course of Mavenclad but before your second course of Mavenclad you will need to discuss delaying your second treatment course.

How do I take Mavenclad?

You take Mavenclad as a pill in two treatment courses, twelve months apart:  

  • in the first course you take Mavenclad pills for up to five consecutive days in the first month and for up to five consecutive days in the second month
  • the second course is taken 12 months later; again you take Mavenclad pills for up to five consecutive days in the first month and for up to five consecutive days in the second month.

The actual number of tablets you have to take will depend on your weight.

People who took part in the clinical trials did not need further treatment with Mavenclad in years three and four. Ongoing studies are monitoring whether there is a need for further treatment in later years.

I’ve found Mavenclad to be quite a convenient treatment to be on. It's nice to do a course of tablets and then not have to worry and not have to remember to take anything else.


Read Jenna's treatment story: Mavenclad

What side effects could I get with Mavenclad?


Common side effects include a reduced white blood cell count (lymphopenia) and herpes (oral herpes and shingles).

Common side effects (affecting more than 1 person in 100):

  • decrease in white blood cells (lymphopenia)
  • herpes virus infection (shingles or cold sores)
  • rash
  • hair thinning

Very rare side effects (affecting less than 1 person in 10,000)

  • tuberculosis

A full list of side effects is included in the manufacturer's Patient Information Leaflet.

Assessment before treatment

Before starting a Mavenclad treatment course you will have tests to check for tuberculosis, HIV and hepatitis. Your white blood cell levels will also be checked.

Assessment during treatment

Once you've started treatment you'll have tests to monitor white blood cell levels at three and seven months after treatment in year one, before you start treatment in year two and again at three and seven months in year two. No additional monitoring is required in year three and four. 

During the coronavirus outbreak, you may find that your regular blood tests happen less frequently, may take place in a different location or may temporarily stop. The Association of British Neurologists has assessed the risks and benefits of blood monitoring for people taking DMDs, and has recommended a safe minimum schedule during this period. The recommendation for Mavenclad is that you should still have the first blood test after each course of treatment, but the second blood test can be delayed if necessary, so long as your white blood cell count is over 0.5. If you notice any new or worsening MS symptoms, you should contact your MS team.

Additional Information

If you have previously had cancer talk to your doctor before starting treatment with Mavenclad. This is because single events of cancer have been seen in those taking Mavenclad. Initial research showed more cases of cancer in those taking Mavenclad compared to those taking placebo. However, further analysis of the data and comparison with data from clinical trials of other disease modifying drugs found no evidence of an increased risk of cancer from taking Mavenclad.

For more information see the manufacturer's Patient Information Leaflet.

How does Mavenclad work?

Mavenclad works by gradually reducing the numbers of certain types of white blood cell (T and B lymphocytes). These are thought to be involved in the abnormal immune response which attacks the myelin coating of nerve cells that causes the damage associated with MS. The components of the immune system involved with fighting infections are largely spared, reducing the risk of infections after treatment compared to some other DMDs. 

Mavenclad research

Evidence for the effectiveness of Mavenclad has come from one large study published in 2010.

  • CLARITY - Mavenclad compared to placebo

CLARITY was a two year, phase III study in more than 1,300 people comparing two doses of Mavenclad against placebo. Compared to placebo, there was a reduction in the relapse rate of 58%. Later analyses of the study results also found that brain volume loss was reduced and numbers of participants with no evidence of disease progression (NEDA) were increased in those taking Mavenclad.​

When researchers focused on the smaller subset of patients in the trial who had highly active RRMS, they found that these patients had a 67% reduction in relapse rate compared to placebo.

​Further research on Mavenclad

  • ChariotMS - Mavenclad compared to placebo in advanced MS

People with more advanced MS are usually excluded from clinical trials and have limited treatment options. Preliminary studies have suggested that Mavenclad may be an effective treatment for people with progressive MS. Researchers want to find out if Mavenclad can help maintain hand and arm function when people with progressive MS have largely lost the ability to walk.

The aim of this study is to test whether Mavenclad can slow down the worsening of hand and arm function in people with more advanced progressive MS. This study is recruiting 200 participants with secondary or primary progressive MS and an EDSS of 6.5-8.5 (unable to walk further than 20 metres with two crutches or unable to walk at all). There is no upper age limit. Participants should be able to complete the nine hole peg test within 3 minutes and, in the judgement of the investigator, have lost some use of their arms or hands in the last 2 years. Half of the participants will take Mavenclad, half will take placebo. The main measure used in the study will be the time it takes to complete the nine hole peg test at the end of the two year trial.

There are 20 trial sites across the UK including locations in London, Belfast, Cardiff and Edinburgh. To find out more about taking part, email the trial team at or visit the trial website CHARIOTMS.

Estimated completion date December 2024.

Further details of this study.

Find out more

National Institute for Health and Care Excellence (NICE)
Cladribine tablets for treating relapsing–remitting multiple sclerosis
NICE technology appraisal guidance 616
Full guideline (link is external)
Scottish Medicines Consortium (SMC)
Cladribine (Mavenclad)
SMC 1300/18
Full guideline (link is external)
Giovannoni G, et al.
A placebo-controlled trial of oral cladribine for relapsing multiple sclerosis.
New England Journal of Medicine 2010;362(5):416-426.
Summary (link is external)
Pakpoor J, et al.
No evidence for higher risk of cancer in patients with multiple sclerosis taking cladribine.
Neurology Neuroimmunology and Neuroinflammation 2015;2:e158.
Full article (link is external)
Mao Z, Álvarez-González C, Allen-Philbey K, et al.
Treating the ineligible: Disease modification in people with multiple sclerosis beyond NHS England commissioning policies.
Mult Scler Relat Disord. 2019;27:247-253.
Summary (link is external)
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