Weight gain has not been reported as a side effect with Mavenclad (generic name: cladribine), an oral treatment used for multiple sclerosis (MS). The most common side effects reported with Mavenclad include upper respiratory tract infections, headache and decreased white blood cell counts.

In addition, weight gain is not typically a common symptom of MS. However, rapid weight gain can be a signal for other more serious conditions or may be due to other medications you take. If you experience weight gain that is sudden or concerning to you, you should contact your health care provider for medical advice.

What type of MS is Mavenclad used for?

In 2019 the FDA approved Mavenclad (cladribine), a purine antimetabolite that is used for the treatment of relapsing forms of multiple sclerosis (MS). Mavenclad is approved to treat relapsing-remitting disease (RRMS) and active secondary progressive disease (SPMS). Mavenclad is not recommended for MS patients with clinically isolated syndrome or as a first-line agent due to its side effects.

Effectiveness of Mavenclad was demonstrated in a clinical trial with 1,326 patients. Mavenclad significantly decreased the number of relapses and the progression of disability in these patients compared to a placebo.

Are there serious warnings with Mavenclad?

Yes, Boxed safety warnings are present on the product labeling for Mavenclad. A Boxed Warning is the most stringent drug safety warning from the FDA.

• Boxed warnings for Mavenclad detail the increased risk of developing cancer with treatment and the possibility of birth defects in an unborn baby.
• Do not take Mavenclad if you have cancer or if you are pregnant or trying to become pregnant. Women and men of reproductive potential who do not plan to use effective contraception should not use Mavenclad because of the risk of fetal harm.

Increased risk of cancer

Mavenclad should not be used in patients with active cancer. Treatment with Mavenclad may increase your risk of developing cancer. Talk to your health care provider about your risk of developing cancer if you receive Mavenclad. Follow your health care provider instructions about screening for cancer.

Pregnancy and birth defects

Mavenclad may cause birth defects in your unborn child if you take this medicine during pregnancy. You should not be pregnant when you start this medication, or become pregnant during treatment and within 6 months after the last dose of each yearly treatment course. Stop taking this medicine and call your doctor right away if you become pregnant while taking this drug.

This risk also exists for female partners of male patients using Mavenclad. Men of reproductive potential who do not plan to use effective contraception should not take Mavenclad because of the risk of fetal harm.

You should have a pregnancy test before you begin your first and second yearly treatment course of Mavenclad to make sure that you are not pregnant. Your doctor will order this test for you at the right time.

Use effective birth control (contraception) on the days on which you take Mavenclad and for at least 6 months after the last dose of each yearly treatment course. If you use the "pill" (oral contraceptives) for birth control talk to your doctor. You should use a second method of birth control on the days on which you take Mavenclad and for at least 4 weeks after your last dose of each yearly treatment course.

Males who take Mavenclad: if your female partner is able to become pregnant, you should use an effective birth control (contraception) during the days that Mavenclad is taken and for at least 6 months after the last dose of each yearly treatment course.

Review all of the warnings and side effects with Mavenclad here.

Bottom Line

• Weight gain has not been reported by the manufacturer as a side effect with Mavenclad (Cladribine).
• The more commonly reported side effects reported with Mavenclad include upper respiratory tract infections, headache and decreased white blood cell counts. Boxed warnings for Mavenclad include increased risk of cancer and birth defects in pregnancy.
• If you experience any sudden, unexpected weight gain, contact your doctor for an evaluation.

This is not all the information you need to know about Mavenclad (cladribine) for safe and effective use. Review the full Mavenclad information here, and discuss this information with your doctor or other health care provider.