What are 8 key Mavenclad side effects to watch out for?

8 key side effects with Mavenclad use include:

• A risk of cancer
• Birth defects in an unborn baby
• A severe, often fatal brain infection known as PML
• Liver toxicity
• Other infections, like shingles, tuberculosis or hepatitis
• Serious allergic reactions
• Heart failure
• Lymphopenia (low white blood cell counts)

What is Mavenclad used for?

Mavenclad (cladribine) is a purine antimetabolite approved for the treatment of adults with relapsing forms of multiple sclerosis (MS), including relapsing-remitting disease and active secondary progressive disease. Mavenclad is not recommended for MS patients with clinically isolated syndrome or as the first treatment for patients with MS due to its safety profile.

Multiple sclerosis is a chronic, inflammatory, autoimmune disease of the nervous system that interferes with signals between the brain and other parts of the body. Symptoms of MS typically first appear in patients between 20 and 40 years of age.

Mavenclad carries a Boxed Warning for an increased risk of cancer and a risk of birth defects in an unborn baby. A Boxed Warning is the FDA’s most prominent safety warning and describes important or life-threatening side effects that may occur with treatment. It appears at the top of the package insert as well as in the Patient Medication Guide.

Your healthcare provider may need to delay or discontinue your treatment with Mavenclad if you have severe or serious side effects.

More frequent, common side effects with Mavenclad can occur, too. These include upper respiratory tract infections, headache, and lymphopenia (low white blood cell counts).

You should not use Mavenclad if you:

• have cancer
• are pregnant, plan to become pregnant, or are a woman of childbearing age or a man able to father a child and you are not using birth control
• are human immunodeficiency virus (HIV) positive
• have active infections, including tuberculosis (TB), hepatitis B or C
• are allergic to cladribine, the active ingredient in Mavenclad
• are breastfeeding.

8 side effects of Mavenclad and how to manage them

1. Cancer

Mavenclad may increase your risk of developing cancer and carries a Boxed Warning for this increased risk.

Types of cancer seen in Mavenclad studies included pancreatic cancer, metastatic melanoma (a serious type of skin cancer), and ovarian cancer.

In the CLARITY clinical study with 1,326 patients, cancer occurred in 1.4% of patients who received a 3.5 mg/kg cumulative dose and 0.9% of those who received the cumulative 5.25 mg/kg dose over 96 weeks (two 48-week treatment periods), compared to none of the patients in the placebo group that received an inactive pill. https://secure.medicalletter.org/TML-article-1577d#d4

Tips for managing the risk of cancer

• You should not use Mavenclad if you currently have cancer. Tell your healthcare provider if you have cancer or are being treated for any type of cancer.
• Before you start Mavenclad treatment, speak with your healthcare provider about your risk of cancer and if you’ve had cancer in the past.
• Follow your healthcare provider’s instructions about screening for cancer.
• Follow your dosing instructions exactly from your doctor and pharmacist. Mavenclad is an oral tablet taken by mouth and is given as two yearly treatment courses. Taking too much Mavenclad can further increase your risk for cancer.
• This medicine is considered a cytotoxic drug and requires special handling. Your hands should be dry when handling the Mavenclad tablet. Swallow your tablet as soon as you remove it from the blister pack.
• Limit contact of the drug with your skin. Avoid touching your nose, eyes and other parts of the body. Wash and dry your hands well after taking your tablet. If you get Mavenclad on your skin or on any surface, wash the area right away with water.
• Don’t change your dose or stop taking the medicine unless your healthcare provider tells you to.

2. Birth defects in pregnancy

Mavenclad can cause birth defects in an unborn child. Do not start Mavenclad treatment if you are pregnant or think you might be pregnant. In addition, due to risk of fetal harm, do not use this medicine if you are a man or woman of reproductive potential and do not plan to use effective contraception.

In women who can become pregnant, your healthcare provider should order a test to rule out pregnancy before you begin your yearly treatment courses of Mavenclad. Your healthcare provider will decide when you need a pregnancy test.

Do not become pregnant during Mavenclad dosing and within 6 months after the last dose of each yearly treatment course. If you become pregnant, stop taking Mavenclad and call your healthcare provider right away.

Tips for managing the risk of birth defects in pregnancy

For women who are able to become pregnant:

• 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.
• Talk to your healthcare provider about which birth control method is best for you.
• For men taking Mavenclad with female partners who are able to become pregnant: Use effective birth control (contraception) during the days on which you take Mavenclad and for at least 6 months after the last dose of each yearly treatment course.

Mavenclad Pregnancy Safety Study

The purpose of the Mavenclad Pregnancy Safety Study is to evaluate the effect of cladribine exposure on pregnancy and infant outcomes. You and your healthcare provider are encouraged to report to the study, which is available for:

• women who become pregnant while taking Mavenclad or during the 6 months after your last dose.
• the female partner (of a man treated with Mavenclad) who becomes pregnant while the man is taking Mavenclad or during the 6 months after his last dose.
• Either you or your healthcare provider can report your information by calling into the study at 1-800-283-8088 ext. 5563 or by fax at 1-781-681-2961.

Tips if you are breastfeeding

• Tell your healthcare provider if you are breastfeeding or plan to breastfeed. It is not known if Mavenclad will pass into your breast milk.
• Do not breastfeed on the days on which you take Mavenclad, and for 10 days after the last dose.
• There is no information available about how much cladribine might get into human milk, if it might change your milk production or how it might affect your breastfed baby.

3. Progressive multifocal leukoencephalopathy (PML)

Progressive multifocal leukoencephalopathy (PML) is a rare but serious brain infection that usually leads to death or severe disability. It is caused by a virus known as the JC virus. PML may be more common in people with a weakened immune system, which can happen with certain medicines or types of diseases.

Tips for managing risk of PML

PML has not yet been seen in patients with multiple sclerosis taking Mavenclad, but could occur. Because it is so serious, you should learn about its possible symptoms, which include:

• Weakness on one side of your body
• Changes in your vision
• Loss of coordination (clumsiness) in your arms and legs
• Changes in your thinking
• Memory loss
• Decreased strength
• Confusion
• Problems with balance
• Changes in your mood, behavior or personality

PML symptoms can get worse over days to weeks and may resemble symptoms of an MS attack. Call your healthcare provider right away if you have any new or worsening signs or symptoms of your MS, any PML symptoms or other concerns.

Your doctor will order a brain imaging test known as an magnetic resonance imaging (MRI) test before you start treatment with Mavenclad. This is typically done no sooner than 3 months before you start treatment.

Related questions

• How effective is Mavenclad for MS?
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4. Liver problems

Mavenclad can cause liver toxicity and other problems. This risk can be higher if you already have liver problems or take medicines that affect your liver. You should not use this drug if you have moderate to severe liver problems.

Your healthcare provider will check your for liver disease by doing standard laboratory blood tests before you start treatment and before each course and cycle of Mavenclad. Lab tests can help to find changes in your liver enzymes and other measures.

In studies, 0.3% of patients treated with Mavenclad had serious liver injury or had to stop treatment, compared to 0% of placebo patients. Most cases of serious liver injury occurred about 30 days after first starting treatment.

Tips for managing risk for liver toxicity

Call your healthcare provider right away if you have any of the following symptoms of liver injury:

• Nausea
• Vomiting
• Your skin or the whites or your eyes turn yellow
• Stomach pain
• Loss of appetite
• Dark-colored urine or light colored stools
• Tiredness, fatigue

5. Other infections

Treatment with Mavenclad can lower the effectiveness of your immune system to help fight off infections. You may be at greater risk of infections caused by bacteria, viruses or fungi. These infections can be very serious or lead to death.

In studies, infections occurred in close to half of all patients (49%) treated with Mavenclad compared to 44% of patients who received an inactive placebo pill. Serious or severe infections occurred in 2.4% of those receiving Mavenclad and 2% of those receiving a placebo.

Tuberculosis (TB), hepatitis B, hepatitis C, and shingles (also called herpes zoster) have occurred with Mavenclad treatment. Some cases of TB and hepatitis have been deadly.

Rarely, infections called opportunistic infections may occur in people with a severely weakened immune system (for example, in patients with advanced HIV infection). Your doctor will test you for HIV to be sure you are not infected.

The most frequent serious infections that have occurred in patients treated with Mavenclad included herpes zoster (shingles) and pyelonephritis (a urinary tract infection of the kidneys). In studies, 6% of Mavenclad-treated patients developed a herpes viral infection (primarily shingles and oral herpes), with 0.2% being serious, compared to 2% of placebo patients.

Tips for managing risk for infections

Tell your healthcare provider right away if you get any common signs of infection, or if they get worse, such as:

• Fever
• Chills
• Loss of appetite
• Body aches, muscle or joint pain
• Stomach (abdominal) pain
• Headache
• Burning, tingling, numbness or itchiness of the skin in the affected area
• Skin blotches, blistered rash and severe pain
• Generally feeling unwell
• Nausea, vomiting
• Cough
• Painful urination

Your healthcare provider may order certain vaccines for you before you start or during treatment with Mavenclad to help lower your risk for certain types of infections.

In some cases, if you have very low white blood cell counts, you may need to take medicine to help prevent herpes infections like shingles.

If you think you have any serious infections, see your doctor right away. Your treatment may need to be stopped or delayed until the infection is cleared.

6. Serious allergic (hypersensitivity) reactions

Serious allergic reactions can occur with cladribine, the active ingredient in Mavenclad. If you have previously had a serious allergic reaction to cladribine, do not use Mavenclad.

In studies, 11% of Mavenclad-treated patients had hypersensitivity reactions, compared to 7% of placebo patients.

Tips for managing risk for serious allergic reactions

Stop treatment and get emergency medical right away if you have any of these signs or symptoms of a serious allergic reaction, like:

• Skin rash
• Swelling or itching of the face, lips, tongue or throat
• Trouble breathing, shortness of breath

7. Heart failure

Mavenclad may cause heart failure. Heart failure is when your heart does not pump blood as well as it should to help supply oxygen to your organs.

In a study, one patient treated with Mavenclad had life-threatening heart failure with myocarditis (inflammation of the heart muscle), which improved after about one week.

Tips for managing the risk for heart failure

Call your healthcare provider or get emergency medical help right away if you have any signs or symptoms of heart failure such as:

• Shortness of breath
• A fast or irregular heartbeat
• Unusual swelling in your body.

8. Lymphopenia (low white blood cells)

Mavenclad causes a temporary decrease in your white blood cells (also called lymphocytes). A significant decrease in white blood cells is known as lymphopenia, which is a common side effect that occurs in about 20% of patients.

White blood cells are part of your normal immune system and are important in helping to fight off infections. Inactive infections that are still in your body, including latent tuberculosis or hepatitis, may be activated when Mavenclad is used.

Your doctor will be sure you do not have any active infection, like HIV, tuberculosis, or hepatitis B or C before each treatment course of Mevanclad. You may need to delay Mavenclad treatment if you have an active infection.

Tips for managing lymphopenia

• Tell your doctor before Mavenclad treatment if you think you have any type of infection, which may have symptoms like a fever, chills, headache, fatigue, muscle ache and pain, stomach pain or loss of appetite.
• Be sure to follow your doctor’s direction for appointments for any laboratory blood tests to check your red and white blood cell counts.
• Low white blood cell counts with Mavenclad can cause serious infections, but your healthcare provider will closely watch your blood cell counts.
• Let your doctor know if you take any other medicines for MS, or that may suppress your immune system or decrease any red or white blood cell counts.
• If you miss any appointments, contact your healthcare provider right away to have it rescheduled as soon as possible.

Most patients recover to acceptable lymphocyte counts by 7 to 9 months after dosing, but this can be variable, especially if you use other treatments that can affect blood cell counts.

This is not all the information you need to know about Mavenclad (cladribine) for safe and effective use and does not take the place of your doctor’s directions. All possible side effects are not listed here.

Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.