Dostarlimab is used to treat adults with certain cancers after other treatments did not work or stopped working, and/or the cancer has returned, or it has spread or cannot be removed by surgery.

Your doctor will make sure you have the correct tumor type to be treated with dostarlimab.

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

Call your doctor at once if you have new or worsening symptoms such as: cough, chest pain, breathing problems, severe stomach pain, diarrhea, bloody or tarry stools, headaches, confusion, severe weakness, vision problems, decreased urination, bruising or bleeding, blood in your urine, dark urine, or yellowing of the skin or eyes.

Dostarlimab is injected into a vein by a healthcare provider. This medicine is injected slowly over 30 minutes.

Dostarlimab is usually given every 3 weeks at first, and then every 6 weeks.

You may need medical tests to help determine how long you should use dostarlimab.

Usual Adult Dose for Endometrial Carcinoma:

Initial dose:
-Dose 1 through Dose 4: 500 mg IV over 30 minutes every 3 weeks
Maintenance dose:
-Subsequent dosing beginning 3 weeks after Dose 4 (Dose 5 onwards): 1000 mg IV over 30 minutes every 6 weeks
Duration of therapy:
-Until disease progression or unacceptable toxicity

Use: For the treatment of adult patients with mismatch repair deficient (dMMR) recurrent or advanced endometrial cancer (EC), as determined by an approved test, that has progressed on or following prior treatment with a platinum-containing regimen and are not candidates for curative surgery or radiation

Usual Adult Dose for Solid Tumors:

Initial dose:
-Dose 1 through Dose 4: 500 mg IV over 30 minutes every 3 weeks
Maintenance dose:
-Subsequent dosing beginning 3 weeks after Dose 4 (Dose 5 onwards): 1000 mg IV over 30 minutes every 6 weeks
Duration of therapy:
-Until disease progression or unacceptable toxicity

Comment:
-This indication is approved under accelerated approval based on tumor response rate and durability of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s).

Use: For the treatment of solid tumors, as determined by an FDA-approved test, that have progressed on or following prior treatment and who have no satisfactory alternative treatment options

Tell your doctor if you have ever had:

• breathing problems; or

• immune system problems.

May harm an unborn baby. You may need a pregnancy test to make sure you are not pregnant. Use birth control while using dostarlimab and for at least 4 months after your last dose. Tell your doctor if you become pregnant.

Do not breastfeed while using dostarlimab, and for at least 4 months after your last dose.

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

Since dostarlimab is given in a medical setting, an overdose is unlikely.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Some side effects may occur during the injection. Tell your caregiver if you feel light-headed, chilled or feverish, itchy, or short of breath.

Dostarlimab strengthens your immune system to help it attack cancer cells, but it may also attack healthy cells and you could develop serious or fatal side effects.

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

• new or worsening cough, shortness of breath;

• chest pain, irregular heartbeats;

• a light-headed feeling, like you might pass out;

• a seizure;

• confusion, hallucinations, eye pain or redness, vision problems;

• severe stomach pain, nausea, vomiting, diarrhea, bloody or tarry stools;

• low red blood cells (anemia)--pale skin, tiredness, cold hands and feet;

• low white blood cell counts--fever, mouth sores, skin sores, sore throat, cough;

• kidney problems--swelling in your ankles, blood in your urine, little or no urination;

• liver problems--right-sided upper stomach pain, loss of appetite, bruising or bleeding, dark urine, jaundice (yellowing of the skin or eyes); or

• signs of a hormonal disorder--frequent or unusual headaches, dizziness, feeling very weak, mood or behavior changes, hoarse or deepened voice, increased hunger or thirst, increased urination, constipation, hair loss, sweating, feeling cold, weight gain or loss.

Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Common side effects of dostarlimab may include:

• abnormal liver function tests;

• nausea, diarrhea, constipation;

• low white blood cell counts, anemia; or

• feeling weak or tired.

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 dostarlimab, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.