See also Warning section.
Redness, itching, pain, or swelling at the injection site may occur. Dizziness, diarrhea, or muscle/joint pain may also occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
People using this medication may have serious side effects. However, you have been prescribed this drug because your doctor has judged that the benefit to you is greater than the risk of side effects. Careful monitoring by your doctor may decrease your risk.
Tell your doctor right away if you have any serious side effects, including: easy bruising/bleeding.
This medication can also cause serious (even fatal) nervous system problems. Tell your doctor right away if you have any symptoms such as drowsiness, trouble sleeping, seizures, mental/mood changes (such as confusion, memory loss), numbness/tingling of arms/legs, or trouble with speaking, reading, writing or understanding.
This medication may lower your ability to fight infections. This may make you more likely to get a serious (rarely fatal) infection or make any infection you have worse. Tell your doctor right away if you have any signs of infection (such as sore throat that doesn't go away, fever, chills).
This medication sometimes causes side effects due to the rapid destruction of cancer cells (tumor lysis syndrome). To lower your risk, your doctor may add a medication and tell you to drink plenty of fluids. Tell your doctor right away if you have symptoms such as: low back/side pain (flank pain), signs of kidney problems (such as painful urination, pink/bloody urine, change in the amount of urine), muscle spasms/weakness.
People using this medication may have worsening of their symptoms (tumor flare). Tell your doctor right away if you have symptoms of tumor flare such as: tender or swollen lymph nodes, chest pain, cough, or pain or swelling at the site of the tumor.
Mosunetuzumab can commonly cause a rash that is usually not serious. However, you may not be able to tell it apart from a rare rash that could be a sign of a severe reaction. Get medical help right away if you develop any rash.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/safety/medwatch-fda-safety-information-and-adverse-event-reporting-program.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.