SAFETY & SIDE EFFECTS
LET’S TALK KESIMPTA SAFETY
Before you start any treatment, it’s important to understand the safety profile and possible side effects.
PROVEN SAFETY PROFILE
KESIMPTA was studied in 2 head-to-head studies vs teriflunomide.
Few people stopped treatment due to side effects: comparable to teriflunomide: 5.7% for KESIMPTA, 5.2% for teriflunomide
Mild to moderate injection-related reactions: 99.8% of injection-related reactions were mild to moderate. They were most common in the first injection and decreased to less than 3% after the 3rd dose
KESIMPTA has a proven safety profile and has been studied for 8 years and counting.
Because safety is so important, KESIMPTA continues to be studied in an ongoing, open-label* extension study.†
*A type of study where participants are aware of the type of treatment they're being given. Interpreting results from open-label studies can be uncertain. They are not considered representative results, since participants chose whether to stay in the trial.
†After the original KESIMPTA studies, over 1700 people continued to participate for further evaluation, where they all took KESIMPTA. The goal of this extended study was to learn about the safety and tolerability of KESIMPTA in the long term, with a focus on injection–related reactions, malignancies, and serious infections for up to 8 years. No conclusions of clinical outcomes can be drawn. (April 2026 data cut-off date.)
POSSIBLE SIDE EFFECTS
KESIMPTA could increase the risk of serious, including life-threatening or fatal, infections:
Hepatitis B virus (HBV) reactivation: Before starting KESIMPTA, you’ll get a blood test for HBV. If you’ve ever had HBV infection, it may become active again during or after treatment with KESIMPTA.
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, and can result in death or severe disability. While no cases of PML were reported in RMS clinical trials with KESIMPTA, it could happen.
Other serious side effects are:
Local injection-site reactions: Symptoms include redness, pain, itching, and swelling.
Injection-related reactions (systemic): Symptoms include fever, headache, pain in the muscles, chills, tiredness, rash, hives, trouble breathing, swelling of the face, eyelids, lips, mouth, tongue and throat, and feeling faint, or chest tightness.
Low immunoglobulins: KESIMPTA may decrease some types of antibodies.
Liver damage: B-cell therapies including KESIMPTA may cause liver damage. Symptoms may include yellowing of the skin and eyes, nausea, vomiting, unusual darkness of urine, and feeling tired or weak.
Your doctor will do blood tests to check your immunoglobulin levels and liver before you start KESIMPTA and while you take it, if needed.
COMMON SIDE EFFECTS
Common side effects of KESIMPTA include upper respiratory tract infections and headache.
Upper respiratory tract infections
Symptoms include sore throat, runny nose, and headache.
Headache
THINGS TO TELL YOUR DOCTOR
Before you take KESIMPTA, it’s important to tell your doctor if you have any infections, or if you:
Have or think you have HBV or PML
Have taken or plan to take medication that affects your immune system
Have a history of liver problems
Had a recent vaccination or have one scheduled
Are pregnant, think you may be, or are planning to be. There is a registry for women who become pregnant during treatment with KESIMPTA. For more information or to register, visit MotherToBaby, call 1-877-311-8972 or send an email to [email protected]
Are breastfeeding or plan to
WALT D.
Dad, Engineer, and Real Patient
Chose KESIMPTA as 1st treatment: 2021
“I felt comfortable getting started after learning about the safety profile and side effects.”
Up Next:
Learn how to use the auto-injector pen step-by-step.
Want more info to help you decide?
Find out why so many people are choosing KESIMPTA.
Want co-pay help?
96% of all prescriptions filled paid as little as $0 out of pocket cost when used with the Co-Pay Plus offer.‡§
All people featured on this webpage are living with relapsing multiple sclerosis, have taken KESIMPTA, and have been compensated for their time.
RMS, relapsing multiple sclerosis.
‡Limitations apply. Valid only for those with private insurance. The Program includes the Co-Pay Plus offer, Plus Card (if applicable), and Rebate, with a combined annual limit up to $18,000. Patient is responsible for any costs once limit is reached in a calendar year. Program not valid (i) under Medicare, Medicaid, TRICARE, VA, DoD, or any other federal or state health care program, (ii) where patient is not using insurance coverage at all, (iii) where the patient’s insurance plan reimburses for the entire cost of the drug, or (iv) where product is not covered by patient’s insurance. The value of this program is exclusively for the benefit of patients and is intended to be credited towards patient out-of-pocket obligations and maximums, including applicable co-payments, coinsurance, and deductibles. Program is not valid where prohibited by law. Patient may not seek reimbursement for the value received from this program from other parties, including any health insurance program or plan, flexible spending account, or health care savings account. Patient is responsible for complying with any applicable limitations and requirements of their health plan related to the use of the Program. Valid only in the United States and Puerto Rico. This Program is not health insurance. Program may not be combined with any third-party rebate, coupon, or offer. Proof of purchase may be required. Novartis reserves the right to rescind, revoke, or amend the Program and discontinue support at any time without notice. See complete Terms & Conditions at start.kesimpta.com.
§2025 data on file.