Tiredness, diarrhea, or nausea may 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, your doctor has prescribed this drug because he or she 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: new/worsening cough, diarrhea with blood/mucus, severe stomach/abdominal pain, mouth/throat sores, symptoms of liver disease (such as nausea/vomiting that doesn’t stop, loss of appetite, yellowing eyes/skin, dark urine), signs of kidney problems (such as change in the amount of urine, pink/bloody urine), easy bruising/bleeding, swelling hands/ankles/feet, unusual weakness, joint stiffness/pain, muscle weakness/tenderness/pain/spasms/cramps, numbness/tingling of arms/legs, loss of coordination, eye redness/pain, sensitivity to light, vision changes, headache that is unusual or doesn’t go away, seizures.

Dostarlimab may cause hormone gland problems (such as thyroid, pituitary, adrenal, pancreas). Your body could make too much or too little hormone. Tell your doctor right away if you have any symptoms such as: cold or heat intolerance, unexplained weight loss/gain, increased thirst/urination, mood or behavior changes (such as decreased sex drive, irritability, forgetfulness), slow/fast/pounding/irregular heartbeat, unusual tiredness, constipation.

Get medical help right away if you have any very serious side effects, including: chest pain, shortness of breath.

Dostarlimab can commonly cause itching or 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 or itching.

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: fever, swollen lymph nodes, 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.

Warnings & Precautions

Before using dostarlimab, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: organ transplant, stem cell transplant with donor cells.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using dostarlimab. Dostarlimab may harm an unborn baby. Your doctor should order a pregnancy test before you start this medication. Ask about reliable forms of birth control while using this medication and for 4 months after stopping treatment. If you become pregnant, talk to your doctor right away about the risks and benefits of this medication.

It is unknown if this drug passes into breast milk. Because of the possible risk to the infant, breast-feeding is not recommended while using this drug and for 4 months after stopping treatment. Consult your doctor before breast-feeding.