See the DrugPatentWatch profile for kesimpta
Does Kesimpta Deplete B Cells?
Yes, Kesimpta (ofatumumab) is a B-cell depleting therapy. It binds to CD20 on B cells, triggering antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, and phagocytosis, which reduces circulating B cells.[1][2]
How Does Kesimpta Target B Cells?
Kesimpta is a fully human anti-CD20 monoclonal antibody administered subcutaneously. It selectively depletes CD20-positive B cells, including naive, memory, and plasmablast-like B cells, while sparing plasma cells (which lack CD20). B-cell counts drop rapidly after the first dose, reaching nadir within weeks, with repopulation over 6-12 months.[1][3]
How Does It Compare to Other B-Cell Depleters?
Kesimpta differs from intravenous anti-CD20 therapies like Rituxan (rituximab) in its subcutaneous delivery and higher potency due to concentration-dependent killing. Unlike Ocrevus (ocrelizumab), which targets both B and T cells indirectly via broader effects, Kesimpta focuses solely on B cells. All share CD20 targeting but vary in dosing and relapse rates in multiple sclerosis trials.[2][4]
Is It Used Only for MS?
Primarily approved for relapsing multiple sclerosis (RMS) in adults, Kesimpta reduces relapses and MRI lesions by depleting pathogenic B cells. It's also approved for chronic lymphocytic leukemia (CLL) in some regions, confirming its B-cell depleting mechanism across autoimmune and oncology uses.[1][5]
What Do Patients Experience with B-Cell Depletion?
B-cell levels recover gradually post-treatment, but monitoring is required due to infection risks from low counts. Common concerns include infusion-like reactions (less with subcutaneous dosing), upper respiratory infections, and rare progressive multifocal leukoencephalopathy (PML).[1][3]
[1]: Kesimpta Prescribing Information (Novartis)
[2]: FDA Approval Summary for Ofatumumab
[3]: Clinical Pharmacology Review - Ofatumumab
[4]: NEJM: Ofatumumab vs Teriflunomide in MS
[5]: EMA Summary for Kesimpta