Dostarlimab-gxly injection is used to treat a certain type of endometrial cancer (cancer that begins in the lining of the uterus) in adults that has progressed or has returned after treatment with other chemotherapy medication(s). Dostarlimab-gxly injection is also used to treat a certain type of solid tumor that has spread to other parts of the body in adults who were previously treated unsuccessfully with another chemotherapy medication and do not have other satisfactory treatment options. Dostarlimab-gxly injection is in a class of medications called monoclonal antibodies. It works by blocking the action of a certain protein in cancer cells. This helps the person's immune system to fight against the cancer cells, and helps to slow tumor growth.

Dostarlimab-gxly injection comes as a solution (liquid) to inject intravenously (into a vein) over 30 minutes by a doctor or nurse in a medical facility or infusion center. It is usually given once every 3 weeks for 4 cycles, and then once every 6 weeks for as long as your doctor recommends you receive treatment.

Dostarlimab-gxly injection may cause serious or life-threatening reactions during an infusion. A doctor or nurse will watch you closely while you are receiving the infusion to be sure you are not having a serious reaction to the medication. Tell your doctor or nurse immediately if you experience any of the following symptoms that may occur during the infusion: chills, flushing, shaking, dizziness, shortness of breath, wheezing, fever, itching, rash, back or neck pain, or feeling faint.

Your doctor may slow down your infusion, permanently or temporarily stop your dostarlimab-gxly injection treatment, or treat you with additional medications depending on your response to the medication and any side effects that you experience. Talk to your doctor about how you are feeling during your treatment.

Your doctor or pharmacist will give you the manufacturer's patient information sheet (Medication Guide) when you begin treatment with dostarlimab-gxly injection and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website (http://www.fda.gov/Drugs/DrugSafety/ucm085729.htm) or the manufacturer's website to obtain the Medication Guide.

Before receiving dostarlimab-gxly injection,

• tell your doctor and pharmacist if you are allergic to dostarlimab-gxly, any other medications, or any of the ingredients in dostarlimab-gxly injection. Ask your pharmacist or check the Medication Guide for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have ever had an organ or bone marrow transplant and if you have or have ever had radiation therapy to your chest area; an autoimmune disease such as Crohn's disease (condition in which the immune system attacks the lining of the digestive tract causing pain, diarrhea, weight loss, and fever), ulcerative colitis (condition which causes swelling and sores in the lining of the colon [large intestine] and rectum), or lupus (condition in which the immune system attacks many tissues and organs including the skin, joints, blood, and kidneys); any condition that affects your nervous system such as myasthenia gravis (a disorder of the nervous system that causes muscle weakness) or Guillain-Barré syndrome (weakness, tingling, and possible paralysis due to sudden nerve damage); any type of lung disease or breathing problems; thyroid problems; or liver disease.
• tell your doctor if you are pregnant or plan to become pregnant. You will need to take a pregnancy test before you receive dostarlimab-gxly. You should not become pregnant while you are receiving dostarlimab-gxly injection and for at least 4 months after your final dose. If you become pregnant while receiving dostarlimab-gxly injection, call your doctor immediately. Dostarlimab-gxly injection may harm the fetus.
• tell your doctor if you are breastfeeding or plan to breastfeed. You should not breastfeed while receiving dostarlimab-gxly injection and for 4 months after your final dose.

If you miss an appointment to receive dostarlimab-gxly injection, call your doctor as soon as possible.

Unless your doctor tells you otherwise, continue your normal diet.

Dostarlimab-gxly may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• nausea
• constipation
• fatigue
• muscle or joint pain

Some side effects can be serious. If you experience any of these symptoms or those listed in the HOW section, call your doctor immediately or get emergency medical treatment:

• cough, chest pain, or shortness of breath
• diarrhea; increase in number of bowel movements; black, tarry, sticky stools, or stools that have blood or mucus in them; or stomach-area pain or tenderness
• yellowing of skin or eyes, dark-colored urine, bleeding or bruising more easily than normal, loss of appetite, severe nausea or vomiting, decreased energy, or pain on right side of stomach area
• headaches, including those that are unusual or will not go away
• changes in mood or behavior (decreased sex drive, irritability, or forgetfulness)
• deepening of voice or hoarseness
• changes in weight (gain or loss)
• weakness
• hair loss
• dizziness or fainting
• vision changes
• increased sweating
• increased urination
• increased sensitivity to light
• fast heartbeat
• feeling more hungry or thirsty than usual
• feeling cold
• change in amount or color of urine; ankle swelling; blood in urine; or loss of appetite
• pale skin or shortness of breath
• rash; skin blisters, peeling, or sores; itching; painful sores or ulcers in mouth, nose, throat, or genital area; fever or flu-like symptoms; or swollen lymph nodes
• rash, stomach area pain, or diarrhea
• swollen lymph nodes, rash or tender skin lumps, cough, shortness of breath, vision changes, or eye pain
• confusion, fever, muscle weakness, balance problems, nausea, vomiting, stiff neck, memory problems, or seizures
• hallucinations (seeing things or hearing voices that do not exist)

Dostarlimab-gxly may cause other side effects. Call your doctor if you have any unusual problems while receiving this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to dostarlimab-gxly. Your doctor will order a lab test before you begin your treatment to see whether your cancer can be treated with dostarlimab-gxly.

Ask your pharmacist any questions you have about dostarlimab-gxly.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

• Jemperli®