Talquetamab is used to treat adults with multiple myeloma who have received at least 4 treatment regimens and their cancer has returned or did not respond to a previous treatment.

Talquetamab is available only under a special program. You must be registered in the program and understand the risks and benefits of talquetamab.

Talquetamab may also be used for purposes not listed in this medication guide.

Tell your medical caregivers if you have symptoms of a serious side effect such as fever, chills, trouble breathing, vomiting, or severe tiredness.

Call your doctor if you have symptoms of neurological problems such as headache, seizures, confusion, problems with thinking or memory, muscle weakness, numbness and tingling, tremor, problems with speech or walking.

Follow all directions on your prescription label and read all medication guides or instruction sheets.

Read the Patient Wallet Card about serious side effects and learn what symptoms to watch for. Keep the card with you at all times.

Talquetamab is given by a healthcare provider as an injection under the skin in the stomach-area, thigh, or another area.

You will need to stay in the hospital for 48 hours after some doses of talquetamab. Talk with your doctor if you have any questions.

You may be given other medications to help prevent serious side effects or allergic reaction. Keep taking these medicines for as long as your doctor has prescribed.

Your treatment with talquetamab may be temporarily or permanently discontinued if you have certain side effects.

You will need medical tests before and during treatment with talquetamab.

Tell your doctor if you have:

• an infection.

May harm an unborn baby. You may need a pregnancy test to make sure you are not pregnant. Use effective birth control while using talquetamab and for at least 3 months after your last dose. Tell your doctor if you become pregnant.

Do not breastfeed while using talquetamab, and for at least 3 months after your last dose.

Call your doctor for instructions if you miss an appointment for your talquetamab injection.

In a medical setting an overdose would be treated quickly.

Avoid driving or hazardous activity for 48 hours after receiving certain doses of talquetamab or until neurological symptoms go away. Your reactions could be impaired.

Get emergency medical help if you have signs of an allergic reaction: hives, difficult breathing, swelling of your face, lips, tongue, or throat.

Tell your medical caregivers if you have signs of cytokine release syndrome (CRS), a serious side effect: fever, chills, trouble breathing, confusion, severe vomiting or diarrhea, fast or irregular heartbeats, feeling light-headed or very tired.

You may get infections more easily, even serious or fatal infections. Call your doctor right away if you have signs of infection such as:

• fever, chills, sore throat;

• mouth sores, red or swollen gums;

• pain or burning when you urinate;

• pale skin, easy bruising, unusual bleeding; or

• chest discomfort, wheezing, dry cough or hack, rapid weight loss.

Talquetamab may cause serious side effects. Call your doctor at once if you have:

• mouth problems or weight loss;

• rash, skin redness or red bumps;

• low blood cell counts--fever, chills, tiredness, mouth sores, skin sores, pale skin, cold hands and feet, feeling light-headed or short of breath;

• neurological problems--headache, jerking muscle movements, rigid muscles, feeling restless, numbness and tingling, confusion, problems speaking, muscle spasms, tremors, double vision, changes in handwriting, problems walking, muscle weakness in body or face, hearing loss, burning, throbbing, or stabbing pain; or

• liver problems--loss of appetite, stomach pain (upper right side), tiredness, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects of talquetamab may include:

• changes in your sense of taste;

• trouble swallowing, dry mouth;

• diarrhea, weight loss;

• muscle or joint pain;

• feeling very tired;

• problems with your fingernails or toenails;

• dry skin and mucous membranes; or

• fever, nose, sinuses or throat infection.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Other drugs may affect talquetamab, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.