Kesimpta (ofatumumab) is a medication used to treat relapsing forms of multiple sclerosis (MS) by targeting and depleting B cells, a type of immune cell involved in the disease process. While it has shown effectiveness in managing MS symptoms and slowing disease progression, understanding the long-term risks associated with Kesimpta is important for patients and healthcare providers.
One of the primary long-term concerns with Kesimpta involves its impact on the immune system. Since Kesimpta works by reducing B cells, it can weaken the body’s ability to fight infections. Over extended periods, this immune suppression may increase the risk of infections, including serious ones like respiratory tract infections and herpes virus-related infections. Patients on long-term Kesimpta therapy need careful monitoring for signs of infection, and preventive measures such as vaccinations should be considered before starting treatment.
Another potential long-term risk is related to the rare but serious brain infection called progressive multifocal leukoencephalopathy (PML). PML is caused by the JC virus and can occur in people with weakened immune systems. Although PML cases are more commonly reported with other MS drugs, vigilance is necessary when using any immune-modulating therapy, including Kesimpta.
There is also concern about the possibility of Kesimpta increasing the risk of certain cancers, as some immune therapies can alter immune surveillance mechanisms that normally help detect and destroy cancer cells. While no definitive link has been established specifically for Kesimpta, ongoing monitoring and adherence to standard cancer screening guidelines are recommended.
Long-term use of Kesimpta may also lead to changes in blood cell counts, such as low levels of white blood cells or other blood components, which can further compromise immune function or cause other hematologic issues. Regular blood tests are important to detect these changes early.
In terms of metabolic effects, current data do not show that Kesimpta causes hyperglycemia (high blood sugar), and it appears to be well tolerated over several years of use without new safety risks emerging. However, patients with pre-existing conditions like diabetes should still be closely monitored.
Injection site reactions are common with Kesimpta since it is administered subcutaneously. Over time, repeated injections may cause local skin reactions such as redness, swelling, or pain, which usually improve but can occasionally persist.
Because Kesimpta affects immune response, it can interfere with the effectiveness of live vaccines. Patients should update vaccinations before starting treatment and avoid live vaccines during therapy to reduce risks.
Psychological effects such as depression or mood changes have been reported with some MS treatments, and while not specifically highlighted for Kesimpta, mental health should be monitored during long-term therapy.
Finally, the long-term safety profile of Kesimpta is still being established as more patients use the drug over extended periods. Clinical extension studies up to four years suggest it is generally well tolerated, but ongoing research and post-marketing surveillance are essential to identify any rare or delayed adverse effects.
In summary, the long-term risks of Kesimpta primarily revolve around immune suppression leading to infections, potential rare brain infections, possible cancer risk, blood cell changes, injection site reactions, and vaccine considerations. Regular medical follow-up, laboratory monitoring, and preventive care are key components to safely managing these risks during prolonged Kesimpta treatment.
