Ofatumumab

• Ofatumumab is a monoclonal antibody that targets CD20-positive B-cells.
• Its primary mechanism of action involves depleting these B-cells, reducing inflammation and nerve damage.
• It is primarily used for treating relapsing forms of multiple sclerosis (RMS).
• Common side effects include injection-related reactions and infections.
• Regular monitoring is essential during Ofatumumab multiple sclerosis treatment.

What is Ofatumumab and How It Works?

Ofatumumab is a human anti-CD20 monoclonal antibody. It is designed to selectively bind to the CD20 protein found on the surface of B-lymphocytes, which are a type of white blood cell. By binding to CD20, Ofatumumab triggers the destruction of these B-cells.

The ofatumumab mechanism of action involves several immune processes that lead to B-cell depletion. Once Ofatumumab binds to CD20, it initiates cell lysis through antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). This targeted depletion of B-cells is crucial because, in certain autoimmune diseases like multiple sclerosis, B-cells are believed to contribute to inflammation and nerve damage by producing antibodies and acting as antigen-presenting cells. By reducing the number of these B-cells, Ofatumumab aims to lessen disease activity and progression.

Ofatumumab: Uses and Multiple Sclerosis Treatment

Ofatumumab is used for the treatment of relapsing forms of multiple sclerosis (RMS) in adults. This includes clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease. Multiple sclerosis (MS) is a chronic, autoimmune disease that affects the brain and spinal cord, leading to a range of neurological symptoms. According to the World Health Organization (WHO), MS affects millions of people worldwide, with relapsing forms being the most common type.

As an ofatumumab multiple sclerosis treatment, it is administered as a subcutaneous injection, typically once a month, after an initial loading dose schedule. Its effectiveness in MS stems from its ability to reduce the frequency of relapses and slow the progression of disability by targeting the B-cells that drive the autoimmune attack on myelin. Clinical trials have demonstrated its efficacy in significantly reducing annualized relapse rates and the number of new or enlarging brain lesions in patients with RMS.

Potential Side Effects of Ofatumumab

Like all medications, Ofatumumab can cause side effects, although not everyone experiences them. Understanding these potential reactions is important for patients undergoing treatment. The most common ofatumumab side effects often include reactions at the injection site and infections.

Common side effects may include:

• Injection-related reactions (e.g., redness, swelling, pain, itching at the injection site)
• Headache
• Upper respiratory tract infections (e.g., common cold, sore throat)
• Urinary tract infections

More serious, though less common, side effects can include more severe infections, a decrease in immunoglobulin levels (which can increase infection risk), and progressive multifocal leukoencephalopathy (PML), a rare but serious brain infection. Patients are advised to discuss all potential risks and benefits with their healthcare provider and report any unusual symptoms promptly. Regular monitoring by a physician is essential to manage and mitigate these potential side effects effectively.