• Keep this leaflet. You may need to read it again.
• If you have any further questions, ask your doctor, pharmacist or nurse.
• If you get any side effects talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. See section 4.

1. What Lunsumio is and what it is used for
2. What you need to know before you use Lunsumio
3. How to take Lunsumio
4. Possible side effects
5. How to store Lunsumio
6. Contents of the pack and other information

The active substance in Lunsumio, mosunetuzumab, is a monoclonal antibody, a type of protein that attaches to specific targets in the body. In this case, mosunetuzumab attaches to a target substance found on B cells, including the cancerous B cells, and another target found on ‘T cells’, a different type of white blood cell. T cells are another part of the body’s defences that can destroy invading cells. By attaching the two cells together like a bridge, Lunsumio encourages the T cells to destroy the cancerous B cells. This helps control the FL and prevent its spread.

• if you are allergic to mosunetuzumab or any of the other ingredients of this medicine (listed in section 6).

If you are not sure, talk to your doctor or nurse before you are given Lunsumio.

Talk to your doctor or nurse before you are given Lunsumio if any of the following apply to you (or you are not sure):

• you have ever had heart, lung or kidney problems
• you have an infection, or have had an infection in the past which lasted a long time or keeps coming back
• you are due to have a vaccine or you know you may need to have one in the near future.

If any of the above apply to you (or you are not sure), talk to your doctor or nurse before having this medicine.

Tell your doctor straight away if you get symptoms of any of the side effects listed below during or after treatment with Lunsumio. You may need additional medical treatment. The symptoms of each side effect are listed in section 4.

• Cytokine release syndrome (CRS) – a condition associated with medicines that stimulate T cells.
  • Before each infusion, you may be given medicines, which help reduce possible side effects of cytokine release syndrome.
  • Haemophagocytic lymphohistiocytosis is a condition where the immune system makes too many infection-fighting cells called histiocytes and lymphocytes. Signs and symptoms may overlap with CRS, your doctor will check for this condition if your CRS does not respond to treatment or lasts longer than expected.
• Immune effector cell-associated neurotoxicity syndrome (ICANS) – a condition associated with effects on the nervous system. Symptoms include feeling confused, problems with memory, language or judgement, disorientation and confusion often accompanied by hallucination (seeing, hearing or feeling things that are not there), and not being able to concentrate.
• Tumour lysis syndrome – some people may get unusual levels of some salts in the blood – caused by the fast breakdown of cancer cells during treatment.
  • Your doctor or nurse will do blood tests to check for this condition. Before each infusion, you should be well-hydrated and may be given medicines that can help reduce high levels of uric acid. These may help reduce possible side effects of tumour lysis syndrome.
• Tumour flare – as your cancer is destroyed, it may react and appear to get worse – this is called ‘tumour flare reaction’.
• Infections – you may get signs of infection, which can vary depending on where in the body the infection is.

This medicine should not be used in children or adolescents under the age of 18. This is because there is no information about use in this age group.

Tell your doctor if you are taking, have recently taken or might take any other medicines. This includes medicines obtained without a prescription and herbal medicines.

It is important to tell your doctor before and during treatment if you are pregnant, think you may be pregnant, or are planning to get pregnant. This is because Lunsumio may affect your unborn baby.

• Do not use Lunsumio during pregnancy, unless after discussion with your doctor, it is agreed that the benefits of treatment outweigh any risk to the unborn baby.

Contraception

Women who could become pregnant must use effective contraception during treatment – and for 3 months after the last dose of Lunsumio.

• Talk to your doctor or nurse about suitable methods of contraception.

Breast-feeding

You must not breast-feed during and for at least 3 months after your last treatment. This is because it is not known whether any Lunsumio passes into breast milk and could therefore affect the baby.

Lunsumio has major influence on your ability to drive, cycle or use any tools or machines Due to the possible symptoms of ICANS, you should be careful while driving, cycling or using heavy or potentially dangerous machines. If you currently have such symptoms, avoid these activities and contact your doctor, nurse, or pharmacist. See section 4 for more information about side effects.

It is given into a vein, as a drip (infusion).

• It is given over 4 hours during the first cycle. Each cycle is 21 days and in the first cycle, you will be given the 4 hour infusion on day 1, day 8 and day 15.
• If side effects are not too severe, the dose may be given over 2 hours during the following cycles.

You may be given other medicines 30 to 60 minutes before you are given Lunsumio. This is to help prevent infusion reactions and fever. These other medicines may include:

• Corticosteroids – such as dexamethasone or methylprednisolone
• Paracetamol
• An antihistamine - such as diphenhydramine

Lunsumio is normally given in cycles of 21 days. The recommended treatment duration is at least 8 treatment cycles. However, depending on side effects and how the disease responds to treatment, you may be given up to 17 cycles.

In cycle 1, you will be given 3 doses of Lunsumio in the 21 days:

• Day 1: 1 mg
• Day 8: 2 mg
• Day 15: 60 mg

In cycle 2, you will be given just one dose:

• Day 1: 60 mg

In cycles 3 to 17, you will be given just one dose:

• Day 1: 30 mg

If you miss an appointment, make another one straight away. For the treatment to be fully effective, it is very important not to miss a dose.

Do not stop treatment with Lunsumio unless you have discussed this with your doctor. This is because stopping treatment may make your condition worse.

Tell your doctor straight away if you notice any of the symptoms of the following serious side effects. You may only get one or some of these symptoms.

Cytokine release syndrome

Symptoms can include:

• fever (38°C or higher)
• chills or shaking chills
• cold or pale clammy skin
• difficulty breathing
• feeling dizzy or lightheaded
• fast or uneven heartbeat
• confusion
• feeling very tired or weak
• fainting
• blurred vision
• headache.

Haemophagocytic lymphohistiocytosis

Symptoms can include:

• fever
• enlarged liver and/or spleen
• skin rash
• lymph node enlargement
• easy bruising
• kidney abnormalities
• breathing problems
• heart problems

Tumour lysis syndrome

Symptoms can include:

• fever
• chills
• feeling or being sick (nausea and vomiting)
• confusion
• being short of breath
• fits (seizures)
• uneven heartbeat
• dark or cloudy urine
• unusual tiredness
• muscle or joint pain.

Shown in blood tests

• increase in potassium, phosphate or uric acid – which can cause kidney problems (part of tumour lysis syndrome)

Tumour flare

Symptoms can include:

• tender swollen lymph nodes
• chest pain
• cough or difficulty breathing easily
• pain at the site of the tumour.

Infections

Symptoms can include:

• fever
• cough
• chest pain
• tiredness
• shortness of breath
• painful rash
• sore throat
• burning pain when passing urine
• feeling weak or generally unwell.

Immune effector cell-associated neurotoxicity syndrome (ICANS)

The symptoms can occur days or weeks after you receive the injection and may initially besubtle.

Symptoms can include:

• confusion/disorientation
• tiredness
• altered mental state
• lowered mental state
• impaired memory

If you have any of these symptoms after treatment with Lunsumio, tell your doctor straight away. You may need medical treatment.

Very common: may affect more than 1 in 10 people

• Rash
• Itchy skin
• Dry skin
• Diarrhoea
• Headache
• Fever
• Chills
• Cytokine release syndrome

Shown in blood tests

• Low levels of some white blood cells (neutropenia)
• Low number of red blood cells, which can cause tiredness and shortness of breath
• Low platelet count, which may make you more likely to bruise or bleed (thrombocytopenia)
• Low level of phosphate, potassium or magnesium
• High level of alanine aminotransferase in the blood

Common: may affect up to 1 in 10 people

• Lung infection
• Infection of upper airways (infection of nose, throat, sinuses)
• Urinary tract infection
• Fever due to low levels of neutrophils (a type of white blood cell)
• Tumour flare
• A serious immune reaction affecting the nervous system (immune effector cell-associated neurotoxicity syndrome)

Shown in blood tests

• Increased levels of liver enzymes, which may be a sign of liver problems

Uncommon: may affect up to 1 in 100 people

• A rapid breakdown of tumour cells resulting in chemical changes in the blood and damage to organs, including the kidneys, heart, and liver (tumour lysis syndrome)
• A condition where the immune system makes too many infection-fighting cells called histiocytes and lymphocytes (haemophagocytic lymphohistiocytosis).

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme Website: http://www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine.

• The active substance is mosunetuzumab.
• Lunsumio 1 mg: Each vial contains 1 milligram (mg) mosunetuzumab in 1 mL at a concentration of 1 mg/mL.
• Lunsumio 30 mg: Each vial contains 30 milligrams (mg) mosunetuzumab in 30 mL at a concentration of 1 mg/mL.
• The other ingredients are: L-histidine, L-methionine, acetic acid, sucrose, polysorbate 20 (E432), water for injections.

Lunsumio is a concentrate for solution for infusion (sterile concentrate). It is a clear, colourless liquid provided in a glass vial.

Each pack of Lunsumio contains one vial.