Kesimpta can cause serious side effects, including:
Infections. Serious infections can happen during treatment with Kesimpta. If you have an active infection, your healthcare provider should delay your treatment until your infection is gone. Kesimpta taken before or after other medicines that weaken the immune system may increase your risk of getting infections.
Tell your healthcare provider right away if you have any infections or get any symptoms, including painful and frequent urination, nasal congestion, runny nose, sore throat, fever, chills, cough, or body aches.
Hepatitis B virus (HBV) reactivation. Before starting treatment, your healthcare provider will do blood tests to check for HBV. If you have ever had HBV infection, the HBV may become active again during or after treatment. Hepatitis B virus becoming active again (called reactivation) may cause serious liver problems, including liver failure or death. You should not receive Kesimpta if you have active hepatitis B liver disease. Your healthcare provider will monitor you for HBV infection during and after you stop using this medicine.
Tell your healthcare provider right away if you get worsening tiredness or yellowing of your skin or white part of your eyes during treatment.
Progressive Multifocal Leukoencephalopathy (PML). PML may happen with Kesimpta. PML is a rare, serious brain infection caused by a virus that may get worse over days or weeks. PML can result in death or severe disability. Tell your healthcare provider right away if you have any new or worsening neurologic signs or symptoms. These may include weakness on one side of your body, loss of coordination in arms and legs, vision problems, changes in thinking and memory which may lead to confusion and personality changes.
Weakened immune system. Kesimpta taken before or after other medicines that weaken the immune system could increase your risk of getting infections.
Who should not take Kesimpta?
Do not use Kesimpta if you:
have active hepatitis B virus infection.
