Lunsumio Velo

Lunsumio Velo is used to treat follicular lymphoma (FL) in adults whose cancer has come back or did not respond to previous treatment, and who have already received two or more treatments.

Lunsumio Velo is a subcutaneous formulation of mosunetuzumab that is administered subcutaneously by a healthcare provider over approximately 30 seconds to 1 minute. This may be more convenient to patients and healthcare providers than intravenous Lunsumio, which is administered over 4 hours.

Lunsumio Velo (mosunetuzumab) gained FDA approval on December 19, 2025, under the accelerated approval designation. Continued approval may be contingent on a continued benefit being shown in clinical trials.

Lunsumio Velo will be given to you by your healthcare provider as an injection under your skin (subcutaneous) in your stomach area (abdomen) or thigh.

• After completing the weekly “step-up dosing schedule” in Cycle 1, Lunsumio Velo is administered every 21 days.
• After Cycle 1, your healthcare provider will decide if you need to continue to take other medicines to help reduce side effects from Lunsumio Velo during future cycles.
• Your healthcare provider will decide how many treatment cycles you will receive of this medicine.

Do not drive, operate heavy machinery, or do other dangerous activities if you develop dizziness, confusion, tremors, sleepiness, or any other symptoms that impair consciousness until your signs and symptoms go away. These may be signs and symptoms of CRS or neurologic problems.

Before receiving Lunsumio Velo, tell your healthcare provider about all of your medical conditions, including if you:

• Have an infection or have had an infection in the past that lasted a long time or keeps coming back.
• Have or had Epstein-Barr Virus.
• Are pregnant or plan to become pregnant
• Are breastfeeding or plan to breastfeed.

It is not known if Lunsumio Velo is safe and effective in children.

Pregnancy

Lunsumio Velo may harm your unborn baby. Tell your healthcare provider right away if you become pregnant or think you may be pregnant during treatment with this medicine.

Females who can become pregnant:

• Your healthcare provider should do a pregnancy test before you start treatment with this medicine
• Use an effective method of birth control (contraception) during your treatment and for 3 months after the last dose of Lunsumio Velo.

Breastfeeding

It is not known if Lunsumio Velo passes into your breast milk. Do not breastfeed during treatment and for 3 months after the last dose of Lunsumio Velo.

Warnings

Cytokine Release Syndrome (Boxed Warning)

Lunsumio Velo carries a Boxed Warning for Cytokine Release Syndrome (CRS), a serious side effect that is common during treatment with this medicine, and can also be severe or life-threatening. Get medical help right away if you develop any signs or symptoms of CRS at any time, including:

• Fever of 100.4°F (38°C) or higher
• Chills
• Low blood pressure
• Fast or irregular heartbeat
• Tiredness or weakness
• Difficulty breathing
• Headache
• Confusion
• Feeling anxious
• Dizziness or light-headedness
• Nausea
• Vomiting

Due to the risk of CRS, you will receive Lunsumio Velo on a step-up dosing schedule.

• This is when you receive smaller “step-up” doses before receiving higher doses of Lunsumio Velo during your first cycle of treatment.
• If your dose of Lunsumio Velo is delayed for any reason, you may need to repeat the “step-up dosing schedule.”
• You may receive medicines to help reduce your risk of CRS before your dose.

Your healthcare provider will check you for CRS during treatment with Lunsumio Velo and may treat you in a hospital if you develop signs and symptoms of CRS. Your healthcare provider may temporarily stop or completely stop your treatment with Lunsumio Velo if you have severe side effects.

Common side effects

The most common side effects of Lunsumio Velo are:

• Injection site reactions
• Tiredness
• Rash
• Cytokine release syndrome (CRS)
• COVID-19
• Muscle and joint pain
• Diarrhea

The most common severe abnormal blood test results with Lunsumio Velo include:

• Decreased white blood cell counts
• Increased uric acid levels.

Serious Side Effects

Lunsumio Velo can cause the following serious side effects.

Neurologic problems

Lunsumio Velo can cause serious and life-threatening neurologic problems. Your healthcare provider will check you for neurologic problems during treatment and may also refer you to a healthcare provider who specializes in neurologic problems. Tell your healthcare provider right away if you develop any signs or symptoms of neurologic problems during or after treatment, including:

• Headache
• Numbness and tingling of the arms, legs, hands, or feet
• Dizziness
• Confusion and disorientation
• Difficulty paying attention or understanding things
• Forgetting things or forgetting who or where you are
• Trouble speaking, reading, or writing
• Sleepiness or trouble sleeping
• Tremors
• Loss of consciousness
• Seizures
• Muscle problems or muscle weakness
• Loss of balance or trouble walking
• Tiredness

Serious infections

Lunsumio Velo can cause serious infections that may lead to death. Your healthcare provider will check you for signs and symptoms of infection before and during treatment. Tell your healthcare provider right away if you develop any signs or symptoms of infection during treatment with this medicine, including:

• Fever of 100.4°F (38°C) or higher
• Cough
• Chest pain
• Tiredness
• Shortness of breath
• Painful rash
• Sore throat
• Pain during urination
• Feeling weak or generally unwell.

Hemophagocytic lymphohistiocytosis (HLH)

Lunsumio Velo can cause overactivity of the immune system, a condition called hemophagocytic lymphohistiocytosis (HLH). HLH can be life-threatening and has led to death in people treated with this medicine. Your healthcare provider will check you for HLH, especially if your CRS lasts longer than expected. Signs and symptoms of HLH include:

• Fever
• Enlarged spleen
• Easy bruising
• Low blood cell counts
• Liver problems.

Low blood cell counts

Low blood cell counts are common during treatment with Lunsumio Velo and can also be serious or severe. Your healthcare provider will check your blood cell counts during treatment with this medicine. Lunsumio Velo can cause the following low blood cell counts:

• Low white blood cell counts (lymphopenia and neutropenia). Low white blood cells can increase your risk for infection.
• Low red blood cell counts (anemia). Low red blood cells can cause tiredness and shortness of breath.
• Low platelet counts (thrombocytopenia). Low platelet counts can cause bruising or bleeding problems.

Growth in your tumor or worsening of tumor-related problems (tumor flare)

Lunsumio Velo can cause a serious or severe worsening of your tumor. Tell your healthcare provider if you develop any of these signs or symptoms of tumor flare during your treatment with Lunsumio Velo:

• Chest pain
• Cough
• Trouble breathing
• Tender or swollen lymph nodes
• Pain or swelling at the site of the tumor

Your healthcare provider may temporarily stop or permanently stop treatment with Lunsumio Velo if you develop severe side effects.

These are not all of the possible side effects of Lunsumio Velo. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Lunsumio Velo (mosunetuzumab-axgb) acts like a bridge and works by attaching to two different targets:

• On one side, it binds to CD3 receptors found on T-cells (a type of immune cell)
• On the other side, it binds to CD20 proteins found on lymphoma cells and some normal B-cells

By connecting these cells, the drug brings T-cells into direct contact with lymphoma cells, allowing the immune system to attack the cancer and causing B-cells to break down and die (a process called lysis).

Lunsumio Velo belongs to the drug class called bispecific CD20-directed CD3 T-cell engagers.

Adult Dose of Lunsumio Velo for Follicular Lymphoma

Each cycle = 21 days.

Cycle 1:

• Day 1: 5 mg subcutaneously
• Day 8: 45 mg subcutaneously
• Day 15: 45 mg subcutaneously

Cycle 2 and beyond:

• Day 1: 45 mg subcutaneously.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

Lunsumio Velo releases cytokines that suppress CYP450 enzymes, increasing exposure to CYP450 substrate drugs. This risk is highest after initial doses and during cytokine release syndrome. Your healthcare provider will monitor you for drug toxicity and adjust dosages accordingly. See the Lunsumio Velo Prescribing Information for further information.

Active ingredient: mosunetuzumab-axgb

Inactive ingredients: acetic acid, histidine, methionine, polysorbate 20, sucrose, and Water for Injection.

Available as a 5 mg/0.5 mL solution in a single-dose vial for subcutaneous injection.

Manufactured by Genentech, Inc., A Member of the Roche Group, 1 DNA Way, South San Francisco, CA 94080-4990.