Common brand names

• Lunsumio

How it is administered

Mosunetuzumab is given as an intravenous (IV) infusion, meaning it is administered directly into your vein by a healthcare professional. The medication is supplied as a sterile solution in single-dose vials and is diluted before use. The dosing schedule involves a step-up approach to help reduce the risk of side effects, especially during the first cycle of treatment. Treatment cycles are typically 21 days long, and the infusion duration and dose amount may vary depending on the cycle and how well you tolerate the medication.

How it works

Mosunetuzumab is a type of immunotherapy called a bispecific antibody. It is designed to help your immune system target and destroy cancer cells. Specifically, mosunetuzumab binds to two different proteins: CD20, which is found on the surface of certain lymphoma (cancer) cells and some healthy B-cells, and CD3, which is found on T-cells, a type of immune cell. By binding to both, mosunetuzumab brings T-cells into close contact with the lymphoma cells, activating the T-cells to attack and kill the cancerous B-cells.

After administration, mosunetuzumab leads to a rapid and sustained reduction in B-cell counts, which is how it helps control the lymphoma. It also causes the release of cytokines, which are signaling proteins that help regulate the immune response. This immune activation is key to its effectiveness but can also lead to some of the side effects seen with this medication.

Who should take it

Mosunetuzumab is indicated for adults with relapsed or refractory follicular lymphoma who have already received at least two previous lines of systemic therapy. This means it is used when the lymphoma has come back or has not responded to other treatments, such as other antibody therapies or chemotherapy.

It is generally considered for patients who have limited options due to their disease not responding to standard treatments. Your healthcare team will determine if mosunetuzumab is appropriate for you based on your treatment history and overall health.

Who should not take it

There are no absolute contraindications listed for mosunetuzumab, but it should not be given to patients with active infections. Caution is advised in patients with a history of recurring or chronic infections, underlying conditions that may predispose to infections, or those who have had significant prior immunosuppressive treatment.

Mosunetuzumab may cause harm to an unborn baby, so it should not be used during pregnancy. Women of childbearing potential should use effective contraception during treatment and for at least 3 months after the last dose. Women should also avoid breastfeeding during treatment and for 3 months after the last dose.

Commonly used with

Mosunetuzumab is typically used as a single agent (on its own) for relapsed or refractory follicular lymphoma after other treatments have failed. It is not usually combined with other cancer therapies, but your healthcare provider may recommend supportive medications such as corticosteroids, antihistamines, and acetaminophen to help prevent or manage side effects like cytokine release syndrome during treatment.

Commonly tested with

In clinical studies, mosunetuzumab has been tested as a single agent in patients with blood cancers, particularly follicular lymphoma. Some patients in studies may have previously received other treatments such as anti-CD20 monoclonal antibodies, alkylating agents, or even CAR T-cell therapy, but mosunetuzumab itself is not typically tested in combination with other cancer drugs in the current approved setting.