Common brand names

• Lunsumio

How it is administered

Mosunetuzumab is given as an intravenous (IV) infusion. This means it is administered directly into your vein through a drip, usually in a hospital or clinic setting under the supervision of a healthcare professional.

The medication is given in cycles, with the first cycle involving gradually increasing doses (step-up dosing) to help reduce the risk of certain side effects. Each treatment cycle lasts 21 days. The typical dosing schedule is:

• Cycle 1 Day 1: 1 mg IV infusion over at least 4 hours
• Cycle 1 Day 8: 2 mg IV infusion
• Cycle 1 Day 15: 60 mg IV infusion
• Cycle 2 Day 1: 60 mg IV infusion (over 2 hours if previous infusions were well-tolerated)
• Cycles 3 and beyond: 30 mg IV infusion every 21 days

Premedication with corticosteroids, antihistamines, and acetaminophen is recommended before each dose in the first two cycles to reduce the risk of reactions.

How it works

Mosunetuzumab is a type of immunotherapy called a bispecific antibody. It is designed to help your immune system find and destroy cancer cells. Specifically, mosunetuzumab binds to two different proteins: CD20, which is found on the surface of certain lymphoma (B) cells, and CD3, which is found on T-cells (a type of immune cell).

By linking these two cells together, mosunetuzumab brings your T-cells into close contact with the lymphoma cells. This activates the T-cells, causing them to attack and kill the cancerous B-cells. In clinical studies, mosunetuzumab has been shown to reduce the number of B-cells in the blood and can lead to significant responses in patients with follicular lymphoma who have already tried other treatments.

Because it activates the immune system, mosunetuzumab can also cause the release of cytokines (immune signaling molecules), which can lead to side effects such as cytokine release syndrome. The medication is given in a step-up dosing schedule to help minimize these risks.

Who should take it

Mosunetuzumab is indicated for adults with follicular lymphoma that has come back (relapsed) or has not responded (refractory) after at least two previous lines of systemic therapy. This means it is used for patients who have tried other treatments, such as chemotherapy or other antibody therapies, and whose disease has either returned or did not improve with those treatments.

It is specifically approved for use in this setting based on studies showing that it can help shrink tumors or eliminate signs of lymphoma in a significant number of patients. If you have follicular lymphoma and have already received two or more types of treatment without success, your doctor may consider mosunetuzumab as an option.

Who should not take it

There are currently no absolute contraindications listed for mosunetuzumab, meaning there are no specific conditions where it must not be used. However, it should not be given to patients with active infections, as it can increase the risk of serious or fatal infections. Caution is also advised in patients with a history of recurring or chronic 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. Breastfeeding is not recommended during treatment and for 3 months after the last dose. The safety and effectiveness in children have not been established.

Commonly used with

Mosunetuzumab is typically used as a single agent for the treatment of relapsed or refractory follicular lymphoma after two or more prior therapies. It is not commonly combined with other medications for this indication, as its approval and clinical studies have focused on its use alone.

However, patients may receive supportive medications such as corticosteroids, antihistamines, and acetaminophen as premedication to reduce the risk of infusion-related reactions and cytokine release syndrome.

Commonly tested with

In clinical studies, mosunetuzumab has been tested as a single agent in patients with relapsed or refractory follicular lymphoma. Some patients in these studies had previously received other treatments, such as anti-CD20 monoclonal antibodies (like rituximab), alkylating agents, or stem cell transplants, but mosunetuzumab itself was not combined with other anti-cancer drugs during the pivotal trials for follicular lymphoma.

Future studies may explore its use in combination with other therapies, but for now, its main use is as a single agent after other treatments have failed.