How long does it take for Kesimpta to work?

Kesimpta (ofatumumab) starts to work to lower B cells within a week of starting treatment. In clinical studies, it reduced B cells to below the lower limit of normal in 77-78% of patients one week after the injection. At 2 weeks after starting treatment, this occurred in 95-96% of patients.

Kesimpta is a monoclonal antibody that’s injected under the skin to treat relapsing forms of multiple sclerosis. It’s injected once a week for 3 weeks, then once monthly. It’s thought to work by lowering the number of B cells that contribute to the worsening of MS.

In studies submitted to the FDA for approval (ASCLEPIOS I and ASCLEPIOS II), Kesimpta lowered the annualized relapse rate compared to another MS medication called Aubagio (teriflunomide). In addition, Kesimpta reduced the risk of worsening MS at 3 months of treatment compared to Aubagio.