Patient Medication Information: uses, side effects, how to take - Darzalex SC
What Darzalex SC is used for:
Darzalex SC is used in adults 18 years or older to treat:
- A type of cancer called multiple myeloma. This is a cancer of your plasma cells which are found in your bone marrow.
- Patients who have a type of blood and bone marrow disorder called smouldering multiple myeloma (SMM) that has a high risk of becoming multiple myeloma.
- Patients newly diagnosed with a blood disorder called light chain (AL) amyloidosis. In AL amyloidosis, abnormal blood cells make excessive amounts of abnormal protein that deposit in various organs, causing these organs to not function properly.
How Darzalex SC works:
Darzalex SC contains the active substance daratumumab. Daratumumab belongs to a group of medicines called monoclonal antibodies. Daratumumab attaches to myeloma cells and works in multiple ways to kill the cancer cells. You may be prescribed Darzalex SC with other multiple myeloma medicines, or you may have used other multiple myeloma drugs previously. Darzalex SC works differently compared to these other medicines. In AL amyloidosis, daratumumab attaches to specific abnormal blood cells in our body so your immune system can destroy them.
The ingredients in Darzalex SC are:
Medicinal ingredients: daratumumab.
Non-medicinal ingredients: L-histidine, L-histidine hydrochloride monohydrate, L-methionine, polysorbate 20, recombinant human hyaluronidase (rHuPH20), sorbitol, water for injection.
Darzalex SC comes in the following dosage form:
Darzalex SC is provided as a solution that is administered by subcutaneous (under the skin) injection. It comes in 15 mL vials. Each vial of solution contains 1800 mg of daratumumab (120 mg/mL).
Do not use Darzalex SC if:
- you are allergic to daratumumab or any of the other ingredients in Darzalex SC. If you are not sure, talk to your doctor or nurse before you are given Darzalex SC.
To help avoid side effects and ensure proper use, talk to your healthcare professional before you take Darzalex SC. Talk about any health conditions or problems you may have, including if you:
are pregnant, think you might be pregnant or are planning to have a baby. If you become pregnant while being treated with Darzalex SC, tell your doctor or nurse immediately. You and your doctor will decide if the benefit of receiving Darzalex SC is greater than the risk to your baby. Women who are being treated with Darzalex SC must use effective contraception during treatment and for at least 3 months after treatment. Darzalex SC may harm your unborn baby.
- are producing breast milk. You and your doctor will discuss if giving your baby breast-milk may harm your baby. This is because the medicine may pass into the mother’s milk and it is not known if it will affect the baby.
- you must not give your baby breast-milk if you are also taking lenalidomide or pomalidomide with Darzalex SC. Talk to your doctor about risks of any other products before deciding to give your baby breast-milk.
have breathing problems, such as asthma or Chronic Obstructive Pulmonary Disease (COPD). You will be given medicines to inhale which will help if you have breathing problems after the injection:
- medicines to help the airways in your lungs stay open (bronchodilators)
- medicines to lower swelling and irritation in your lungs (corticosteroids)
- had shingles (herpes zoster).
- had or might now have a hepatitis B virus infection.
- have a history of heart problems. Darzalex SC should not be used in light chain (AL) amyloidosis patients with highly advanced heart disease outside of clinical trials.
If you need a blood transfusion, you will have a blood test first to match your blood type. Darzalex SC can affect the evaluation of the results of this blood test. Tell the person doing the test that you are taking Darzalex SC.
Other warnings you should know about:
Administration-related reactions (systemic reactions related to administration):
Before and after each injection of Darzalex SC, you will be given medicines that help to lower the chance of administration-related reactions. These reactions can happen when you are given the medication or in the 3 days after the injection. These reactions are most likely to happen at the first injection.
Tell your doctor or nurse immediately if you get any of the symptoms of an administration-related reaction. These symptoms include:
- chills
- sore throat/throat tightness
- fever
- cough
- feeling sick
- itchy, runny or blocked nose
- feeling short of breath or other breathing problems including wheezing
- increased blood pressure
- dizziness or light-headedness
- headache
- rash or hives
- nausea
- vomiting
- itchiness
Although rare, you may have a severe allergic reaction. Tell your doctor or nurse immediately if you get any of the symptoms of a severe allergic reaction, which include:
- swollen face, lips, mouth, tongue or throat
- difficulty swallowing or breathing
- an itchy rash (hives)
- eye pain
- blurred vision
Your doctor may decide not to use Darzalex SC if you have a severe administration-related reaction.
Injection site reactions: Skin reactions at or near the injection site (local), including injection site reactions, can happen with Darzalex SC. Symptoms may include itching, swelling pain, bruising, bleeding, or redness of the skin.
Infections: Darzalex SC may increase the occurrence of infections. These infections could be severe, life-threatening or potentially fatal. Tell your healthcare professional if you develop fever, feel very tired, have a cough or have flu-like symptoms.
Hepatitis B Virus: Tell your doctor if you have ever had or might now have a hepatitis B virus infection. This is because Darzalex SC could cause hepatitis B virus to become active again. Your doctor will check you for signs of this infection before, during and for some time after treatment with Darzalex SC. Tell your doctor right away if you get worsening tiredness or yellowing of your skin or white part of your eyes.
Heart problems in patients with light chain (AL) amyloidosis:
Heart problems, in some cases fatal, have occurred. Your healthcare professional will monitor you closely during treatment with Darzalex SC. Call your healthcare professional right away if any of the following symptoms occur: chest pain, feeling faint, swollen legs, shortness of breath, or abnormal heart rhythm.
Changes in blood tests: Darzalex SC can affect the results of blood tests to match your blood type. This interference can last for up to 6 months after your final dose of Darzalex SC. Your healthcare professional should do blood tests to match your blood type before you start treatment with Darzalex SC. Tell all of your healthcare professionals that you are being treated with Darzalex SC before receiving blood transfusions.
Decreased blood cell counts: Darzalex SC can decrease white blood cell counts which help fight infections, and blood cells called platelets which help to clot blood. Tell your healthcare professional if you develop fever, trouble breathing, cough, burning or pain when you urinate, or any other signs and symptoms of infection, or if you have signs of bruising or bleeding.
Pregnancy: Lenalidomide and pomalidomide are expected to be harmful for an unborn baby. When Darzalex SC is given in combination with either of these medications, you must also read the patient medication information for lenalidomide or pomalidomide. When lenalidomide or pomalidomide is used, you must follow the pregnancy prevention programme for these medications. Other medicines used together with Darzalex SC may also harm an unborn baby. You should also read the patient medication information for these other medications.
Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements or alternative medicines.
Interactions with other drugs, vitamins, minerals, natural supplements or alternative medicines have not been established with Darzalex SC.
How to take Darzalex SC:
- Darzalex SC will be given to you by a doctor or nurse.
- It is given as an injection under your skin (“subcutaneous injection”) over approximately 3 to 5 minutes.
- It is given in the stomach area (abdomen).
Usual dose:
The usual dose of Darzalex SC is 1800 mg of daratumumab (1800 mg/15 mL). Darzalex SC may be given alone or together with other medicines used to treat multiple myeloma.
For AL amyloidosis, Darzalex SC is given with bortezomib, cyclophosphamide and dexamethasone.
When given alone or with some medicines, Darzalex SC is given as follows:
- once a week for the first 6, 8 or 9 weeks
- then once every 2 or 3 weeks for 15, 16 or up to 48 weeks
- then once every 4 weeks after that as long as your condition does not worsen
Depending on which other medicines Darzalex SC is given together with, your doctor may change the time between doses as well as how many treatments you will receive.
Other medicines given during treatment with Darzalex SC:
Before each injection of Darzalex SC you will be given other medicines that help to lower the chance of infections, inflammations or allergic reactions. These may include:
- medicines for an allergic reaction (anti-histamines)
- medicines for inflammation (corticosteroids)
- medicines for fever (such as acetaminophen)
- medicines to prevent or treat an infection (anti-microbials)
After each injection of Darzalex SC you will be given other medicines (such as corticosteroids) to lower the chance of a reaction after your injection.
People with breathing problems:
If you have breathing problems, such as asthma or Chronic Obstructive Pulmonary Disease (COPD), you will be given medicines to inhale which help your breathing problems:
- medicines to help the airways in your lungs stay open (bronchodilators)
- medicines to lower swelling and irritation in your lungs (corticosteroids)
You may be given medicines to lower the chance of getting shingles.
Overdose:
This medicine will be given by your doctor or nurse. In the unlikely event that you are given too much (an overdose) your doctor will check you for side effects.
| If you think you, or a person you are caring for, have taken too much Darzalex SC, contact a healthcare professional, hospital emergency department, regional poison control centre or Health Canada’s toll-free number, 1-844 POISON-X (1-844-764-7669) immediately, even if there are no signs or symptoms. |
|---|
Missed dose:
It is very important to go to all your appointments. If you miss an appointment, tell your doctor and make another one as soon as possible.
Possible side effects from using Darzalex SC:
Darzalex SC is generally well-tolerated, however, like all medicines, this medicine can cause side effects.
These are not all the possible side effects you may have when taking Darzalex SC. If you experience any side effects not listed here, tell your healthcare professional.
Side effects of Darzalex SC (taken alone or in combination with other drugs) that may affect more than 1 in 5 people (≥20%) include:
- feeling tired
- nausea
- diarrhea
- constipation
- abdominal pain
- back pain
- cough
- low number of white blood cells (neutropenia)
- low number of a type of blood cell called platelets (thrombocytopenia)
- fever
- swelling
- infections of the airways – such as nose, sinuses or throat
- peripheral sensory neuropathy (numbness or tingling in feet or hands)
- low level of potassium in the blood (hypokalemia)
- COVID-19
- difficulty falling asleep
Other side effects affecting more than 1 in 20 people (≥5%) include:
- chills
- muscle spasms
- headache
- dizziness
- fainting
- loss of appetite
- feeling very weak
- vomiting
- stomach ache
- pain in the chest, arms, legs, muscles, joints, or bones
- pain in the mouth or throat
- rash or itchy skin
- lung infection (such as pneumonia)
- flu or flu-like illness, stuffy nose
- prickling or burning sensation on the skin (paresthesia)
- trembling or shaking hands (tremor)
- altered taste
- urinary tract infection
- low number of white blood cells (lymphopenia, leukopenia)
- decrease in levels of calcium in your blood
- decrease in levels of potassium in your blood
- increase in blood sugar
- increased (hypertension) or decreased (hypotension) blood pressure
- anxiety or depression
- kidney impairment
- shortness of breath (including due to build-up of fluid in the lungs)
- weight decrease
- blurry vision
Serious side effects and what to do about them
| Frequency/Side Effect/Symptom | Talk to your healthcare professional | Stop taking this drug and get immediate medical help | |
|---|---|---|---|
| Frequency/Side Effect/Symptom | Talk to your healthcare professional | Stop taking this drug and get immediate medical help | |
| Only if severe | In all cases | ||
| Only if severe | In all cases | ||
| Very common | |||
| Anemia (low number of red blood cells): Fatigue, loss of energy, weakness, shortness of breath | ✓ | ||
| Neutropenia (low number of white blood cells): Fatigue, loss of energy, weakness, shortness of breath | ✓ | ||
| Thrombocytopenia (low number of platelets): Fatigue, loss of energy, weakness, shortness of breath | ✓ | ||
| Upper respiratory tract infections: Infected nose, sinuses or throat, cold | ✓ | ||
| Common | |||
| Administration-related reactions: Chills, sore throat, cough, feeling sick, itchy, runny or blocked nose, feeling short of breath or other breathing problems, increased blood pressure. | ✓ | ||
| Atrial fibrillation (Irregular or rapid heartbeat) | ✓ | ||
| Bleeding problems: Blood in your stools, coughing up blood | ✓ | ||
| High fever | ✓ | ||
Lung infections such as:
(symptoms of lung infections may include congestion, cough, sore throat, body ache, tiredness and fever) | ✓ | ||
Infections such as:
| ✓ | ||
| Pancreatitis (inflamed pancreas): Abdominal pain, fever, nausea, vomiting | ✓ | ||
| Severe diarrhea: Increased number of bowel movements, watery or bloody stool, stomach pain and/or cramps | ✓ | ||
| Uncommon | |||
| Cytomegalovirus infection (herpes virus infection): Fever, sore throat, fatigue or swollen glands. This virus can cause infections in other parts of the body, such as the lung (cough or breathing trouble), eyes (change in vision or eye pain), and intestines (diarrhea or stomach pain). | ✓ | ||
| Rare | |||
| Severe allergic reaction: Swollen face, lips, mouth, tongue or throat, difficulty swallowing or breathing, an itchy rash (hives), eye pain, blurred vision. | ✓ | ||
If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, tell your healthcare professional.
Reporting side effects
You can report any suspected side effects associated with the use of health products to Health Canada by:
NOTE: Contact your healthcare professional if you need information about how to manage your side effects. The Canada Vigilance Program does not provide medical advice. |
Storage:
Darzalex SC will be stored in a refrigerator at 2-8˚C.
If you want more information about Darzalex SC:
- Talk to your healthcare professional
- Find the full product monograph that is prepared for healthcare professionals and includes the Patient Medication Information by visiting the Health Canada Drug Product Database website (Drug Product Database: Access the database ); the manufacturer's website (innovativemedicine.jnj.com/canada); or by calling 1-800-567-3331 or 1-800-387-8781.
Janssen Inc., a Johnson & Johnson company
Toronto, Ontario, M3C 1L9
Date of Authorization: 2026-10-02
© Johnson & Johnson and its affiliates 2026
All trademarks used under license.