How it is administered

Ofatumumab is given as an intravenous (IV) infusion. The medication comes in single-use vials and is diluted in a saline solution before being administered through a vein. The infusion schedule and dosage depend on the specific blood cancer being treated, but for chronic lymphocytic leukemia (CLL), it is typically given in cycles, with the first dose being 300 mg, followed by 1,000 mg doses on specific days in subsequent cycles. The infusion is administered in a healthcare setting where you can be monitored for any reactions.

How it works

Ofatumumab is a monoclonal antibody that targets the CD20 protein found on the surface of B-cells, which are a type of white blood cell involved in some blood cancers. By binding to CD20, ofatumumab helps the immune system recognize and destroy these B-cells. The medication works through two main mechanisms: complement-dependent cytotoxicity and antibody-dependent cell-mediated cytotoxicity. This means it recruits other parts of your immune system to attack and kill the cancerous B-cells. Ofatumumab is not internalized or shed from the cell surface after binding, allowing for sustained activity against the targeted cells. Over time, this leads to a reduction in the number of abnormal B-cells, helping to control the progression of the disease.

Who Should take it

Ofatumumab is indicated for adults with chronic lymphocytic leukemia (CLL). It can be used in combination with other chemotherapy agents such as chlorambucil for previously untreated patients who are not suitable for fludarabine-based therapy, with fludarabine and cyclophosphamide for relapsed CLL, as extended treatment for patients who have responded to at least two prior therapies, and for those with CLL refractory to fludarabine and alemtuzumab. While not specifically approved for follicular lymphoma, its mechanism of action is similar to other anti-CD20 antibodies used in B-cell blood cancers, and it may be considered in certain clinical scenarios at the discretion of a hematologist.

Who should not take it

Ofatumumab should not be used in patients with known hypersensitivity to the drug or any of its components. It should be avoided in patients with active hepatitis B infection, as it can cause reactivation of the virus, which may lead to serious or fatal liver problems. Caution is also advised in patients with a history of severe infusion reactions or those with severe, uncontrolled infections. Live viral vaccines should not be given during or shortly after treatment with ofatumumab, as the immune response may be weakened.

Commonly used with

Ofatumumab is often used in combination with other chemotherapy agents for CLL, such as:

• Chlorambucil (for previously untreated patients)
• Fludarabine and cyclophosphamide (for relapsed CLL)

It may also be used as a single agent for extended treatment in certain patients who have responded to prior therapies.

Commonly tested with

Ofatumumab has been tested in clinical trials with:

• Chlorambucil
• Fludarabine
• Cyclophosphamide

These combinations have been studied for their effectiveness in treating different stages and types of CLL. Ofatumumab has also been studied as a single agent for patients with refractory or relapsed disease.