Overview
11 DESCRIPTION Ofatumumab is a recombinant human monoclonal immunoglobulin G1 (IgG1) antibody that binds to human CD20 expressed on B-cells. Ofatumumab is produced in a murine NS0 cell line and consists of two IgG1 heavy chains and two kappa light chains with a molecular weight of approximately 146 kDa. KESIMPTA (ofatumumab) injection is a sterile, preservative-free solution for subcutaneous use.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action 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. 12.2 Pharmacodynamics B-cell Depletion For B-cell counts, assays for CD19+ B-cells are used because the presence of ofatumumab interferes with the CD20 assay. In Study 1 and Study 2, KESIMPTA administered as recommended, resulted in a reduction of CD19+ B-cells to below the LLN in 77.0% and 78.8% of patients, respectively, one week after treatment initiation, and in 95.0% and 95.
Indications
- 1 INDICATIONS AND USAGE 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. ( 1 )
Common Doses
- 20 mg
Dosage
2 DOSAGE AND ADMINISTRATION Before 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.
Contraindications
- 4 CONTRAINDICATIONS 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. Hypersensitivity reactions have included anaphylaxis and angioedema [see Warnings and Precautions (5.2)] . Active HBV infection. ( 4 ) History of hypersensitivity to ofatumumab or life-threatening injection-related reaction to KESIMPTA. ( 4 )
Side Effects
- 6 ADVERSE REACTIONS The 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.
Interactions
- 7 DRUG INTERACTIONS 7.1 Immunosuppressive or Immune-Modulating Therapies Concomitant usage of KESIMPTA with immunosuppressant drugs, including systemic corticosteroids, may increase the risk of infection. Consider the risk of additive immune system effects when coadministering immunosuppressive therapies with KESIMPTA. When switching from therapies with immune effects, the duration and mechanism of action of these therapies should be taken into account because of potential additive immunosuppressive effects when initiating KESIMPTA.