Ofatumumab
/api/v1/drug/ofatumumabMechanism of action
Sourced from openFDAThe precise mechanism by which ofatumumab exerts its therapeutic effects in multiple sclerosis is unknown, but is presumed to involve binding to CD20, a cell surface antigen present on pre-B and mature B lymphocytes. Following cell surface binding to B lymphocytes, ofatumumab results in antibody-dependent cellular cytolysis and complement-mediated lysis.
Indications
Sourced from openFDA- KESIMPTA is indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults. KESIMPTA is a CD20-directed cytolytic antibody indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults.ICD-10: G35
Contraindications
Sourced from openFDA- KESIMPTA is contraindicated in patients with: Active HBV infection [see Warnings and Precautions (5.1)] . History of hypersensitivity to ofatumumab or life-threatening injection-related reaction to KESIMPTA.contraindicated
Dosage & administration
Sourced from openFDABefore initiating KESIMPTA, screen for Hepatitis B virus (HBV) and obtain serum quantitative immunoglobulins, aminotransferases, alkaline phosphatase, and bilirubin. ( 2.1 ) Administer KESIMPTA by subcutaneous injection only. ( 2.2 , 2.3 ) Initial Dosing: 20 mg administered at Weeks 0, 1, and 2. ( 2.2 ) Subsequent Dosing: 20 mg administered monthly starting at Week 4. ( 2.2 ) 2.1 Assessments Prior to First Dose of KESIMPTA Hepatitis B Virus Screening Prior to initiating KESIMPTA, perform Hepatitis B virus (HBV) screening. KESIMPTA is contraindicated in patients with active HBV confirmed by positive results for Hepatitis B surface antigen [HBsAg] and anti-HBV tests. For patients who are negative for HBsAg and positive for Hepatitis B core antibody [HBcAb+] or are carriers of HBV [HBsAg+], consult liver disease experts before starting and during treatment with KESIMPTA [see Warnings and Precautions (5.1)] . Serum Immunoglobulins Prior to initiating KESIMPTA, perform testing for quantitative serum immunoglobulins [see Warnings and Precautions (5.3)] . For patients with low serum immunoglobulins, consult immunology experts before initiating treatment with KESIMPTA.
Warnings & precautions
Sourced from openFDAInfections: Serious, including life-threatening and fatal infections, have occurred in patients treated with anti-CD20 therapies. Delay KESIMPTA administration in patients with an active infection until the infection is resolved. Vaccination with live-attenuated or live vaccines is not recommended during treatment with KESIMPTA and after discontinuation, until B-cell repletion. ( 5.1 ) Injection-Related Reactions and Hypersensitivity Reactions: Management for injection-related reactions and hypersensitivity reactions depends on the type and severity of the reaction. ( 4 , 5.2 ) Reduction in Immunoglobulins: Monitor the level of immunoglobulins at the beginning, during, and after discontinuation of treatment with KESIMPTA until B-cell repletion. Consider discontinuing KESIMPTA if a patient develops a serious opportunistic infection or recurrent infections if immunoglobulin levels indicate immune compromise. ( 5.3 ) Liver Injury: Clinically significant liver injury has occurred. Obtain serum aminotransferases, alkaline phosphatase, and bilirubin levels before initiating KESIMPTA, and during treatment as clinically indicated. Discontinue KESIMPTA in patients with evidence of liver injury in the absence of an alternative etiology. ( 5.4 ) Fetal Risk: May cause fetal harm based on animal data. Advise females of reproductive potential of the potential risk to a fetus and to use an effective method of contraception during treatment and for 6 months after stopping KESIMPTA.
Adverse reactions
Sourced from openFDAThe following clinically significant adverse reactions are discussed in greater detail elsewhere in the labeling: Infections [see Warnings and Precautions (5.1)] Injection-Related Reactions and Hypersensitivity Reactions [see Warnings and Precautions (5.2)] Reduction in Immunoglobulins [see Warnings and Precautions (5.3)] Liver Injury [see Warnings and Precautions (5.4)] Most common adverse reactions (incidence greater than 10%) are upper respiratory tract infection, headache, injection-related reactions, and local injection site reactions. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Novartis Pharmaceuticals Corporation at 1-888-669-6682 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Approximately 1500 patients with RMS received KESIMPTA in clinical studies. In Study 1 and Study 2, 1882 patients with RMS were randomized, 946 of whom were treated with KESIMPTA for a median duration of 85 weeks; 33% of patients receiving KESIMPTA were treated for up to 120 weeks [see Clinical Studies (14.1)] .
Use in specific populations
Sourced from openFDA8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to KESIMPTA during pregnancy. Healthcare providers are encouraged to enroll pregnant patients, or pregnant women may register themselves in the MotherToBaby Pregnancy Study in Multiple Sclerosis by calling 1-877-311-8972, by sending an email to MotherToBaby@health.ucsd.edu, or by going to www.mothertobaby.org/join-study. Risk Summary There are no adequate data on the developmental risk associated with the use of KESIMPTA in pregnant women. Ofatumumab may cross the placenta and cause fetal B-cell depletion based on findings from animal studies. No teratogenicity was observed after intravenous administration of ofatumumab to pregnant monkeys during organogenesis. However, increased mortality, depletion of B-cell populations, and impaired immune function were observed in the offspring, in the absence of maternal toxicity, at plasma levels higher than that in humans ( see Data ). Although there are no data on ofatumumab, monoclonal antibodies can be actively transported across the placenta, and ofatumumab may cause immunosuppression in the in utero -exposed infant (see Clinical Considerations ). In the U.S.
Pharmacokinetics
Sourced from openFDA- Metabolism
- Absorption A subcutaneous dose of 20 mg every 4 weeks leads to a mean AUC tau of 483 mcg h/mL and a mean C max of 1.43 mcg/mL at steady state. After subcutaneous administration, ofatumumab is believed to be predominantly absorbed via the lymphatic system similarly to other therapeutic monoclonal antibodies.
Approval history
Sourced from openFDA- Oct 26, 2009BLABLA125326Novartis
FAERS reports
- 1Fatigue5,47817%
- 2Headache4,59314%
- 3Pyrexia3,53411%
- 4Pain3,52411%
- 5Chills3,45911%
- 6Influenza Like Illness2,8508.8%
- 7Nausea1,7915.5%
- 8Multiple Sclerosis Relapse1,6615.1%
- 9Covid-191,5154.7%
- 10Asthenia1,4774.6%
- 11Multiple Sclerosis1,4394.4%
- 12Gait Disturbance1,4144.4%
- 13Hypoaesthesia1,3794.3%
- 14Feeling Abnormal1,3454.1%
- 15Malaise1,3404.1%
Clinical trials
The 10 most recently updated of 191 ClinicalTrials.gov registrations naming Ofatumumab as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.
- Kesimpta (Ofatumumab) in Greek Multiple Sclerosis Patients - an Observational StudyRecruiting · Observational · 160 enrolled · Novartis PharmaceuticalsNCT06486779updated 2026-06-11
- Retinal Atrophy and Neurofilament Light Chain in People With Multiple Sclerosis Taking OfatumumabEnrolling by invitation · Observational · 75 enrolled · Johns Hopkins UniversityNCT06167642updated 2026-06-10
- Safety and Efficacy of Combined B Cell Depleting theRapy And Daratumumab In Autoimmune EncephalitisRecruiting · Phase 3 · Interventional · 200 enrolled · The First People's Hospital of ChangzhouNCT06867991updated 2026-06-09
- A Study to Learn More About The Safety of Diroximel Fumarate (VUMERITY®) in Participants Who Took it During Pregnancy And About the Health of Their BabiesActive not recruiting · Observational · 1,178 enrolled · BiogenNCT05688436updated 2026-06-04
- Switch to Ofatumumab and Level of ImmunoglobulinsNot yet recruiting · Observational · 115 enrolled · University Hospital, LilleNCT07625800updated 2026-06-04
- A NIS Evaluating Various Injectable and Oral Treatments in Patients With Relapsing Multiple SclerosisRecruiting · Observational · 800 enrolled · Novartis PharmaceuticalsNCT05344469updated 2026-06-01
- Study Evaluating Kesimpta® Treatment Effects in Patients With Relapsing Multiple Sclerosis Transitioning From Other TherapiesCompleted · Observational · 307 enrolled · Novartis PharmaceuticalsNCT05566756updated 2026-05-29
- A Multicenter Study of Continued Current Therapy vs Transition to Ofatumumab After Neurofilament (NfL) ElevationActive not recruiting · Phase 4 · Interventional · 136 enrolled · Novartis PharmaceuticalsNCT05090371updated 2026-05-29
- Long-term Safety, Tolerability and Effectiveness Study of Ofatumumab in Patients With Relapsing MSActive not recruiting · Phase 3 · Interventional · 1,882 enrolled · Novartis PharmaceuticalsNCT03650114updated 2026-05-27
- A Non-interventional Study Evaluating Clinical Utility and Implications on Improved Patient Management of Serum Neurofilament as a Prognostic Marker for Disease Activity in Patients With Relapsing Multiple SclerosisRecruiting · Observational · 700 enrolled · Novartis PharmaceuticalsNCT06551519updated 2026-05-22
Frequently asked questions
- How does Ofatumumab work?
- The precise mechanism by which ofatumumab exerts its therapeutic effects in multiple sclerosis is unknown, but is presumed to involve binding to CD20, a cell surface antigen present on pre-B and mature B lymphocytes. Following cell surface binding to B lymphocytes, ofatumumab results in antibody-dependent cellular cytolysis and complement-mediated lysis.
- What is Ofatumumab used for?
- According to FDA labeling, Ofatumumab carries indications including: KESIMPTA is indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults. KESIMPTA is a CD20-directed cytolytic antibody indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
- What class of drug is Ofatumumab?
- Ofatumumab is classified as CD20 (Clusters of Differentiation 20) inhibitors, Monoclonal antibodies, CD20-directed Cytolytic Antibody, CD20-directed Antibody Interactions.
- What are the brand names for Ofatumumab?
- Ofatumumab is marketed under brand names including Arzerra, Kesimpta.
- What are the contraindications for Ofatumumab?
- Ofatumumab labeling lists contraindications including: KESIMPTA is contraindicated in patients with: Active HBV infection [see Warnings and Precautions (5.1)] . History of hypersensitivity to ofatumumab or life-threatening injection-related reaction to KESIMPTA.. Always consult the full prescribing information and a clinician.
ofatumumab is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.