Class Name(s):

• 10:00 Antineoplastic Agents

Brand Name(s):

• Grafapex^®

IMPORTANT WARNING:

Treosulfan injection causes a severe decrease in the number of blood cells in your body. This decrease may cause serious or life-threatening infections or bleeding. If you experience any of the following symptoms, call your doctor immediately: pale skin; weakness; unusual bruising or bleeding; black or bloody stools; vomit that is bloody or looks like coffee grounds; diarrhea; or sore throat, fever, chills, cough, or other signs of infection.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain tests, during and after your treatment to check your body's response to treosulfan injection to see how your blood cells are affected by this drug.

WHY is this medicine prescribed?

Treosulfan injection is used to treat acute myelogenous leukemia (AML; cancer of white blood cells) and myelodysplastic syndrome (condition in which the bone marrow does not produce enough healthy blood cells) in patients who will be having a stem cell transplant. Treosulfan is in a class of medications called alkylating agents. It works by killing blood stem cells in your body before a stem cell transplant.

HOW should this medicine be used?

Treosulfan injection comes as a powder to be mixed with liquid to be injected intravenously (into a vein) over a period of 2 hours by a doctor or nurse in a medical facility. It is usually given once a day for 3 days before stem cell transplant.

Treosulfan injection may cause nausea and vomiting. Your doctor will give you another medication to help prevent nausea and vomiting before and during therapy with treosulfan injection.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

Are there OTHER USES for this medication?

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

What SPECIAL PRECAUTIONS should I follow?

Before receiving treosulfan injection,

• tell your doctor or pharmacist if you are allergic to this medication, any part of this medication, or any other medications, foods or substances. Tell your doctor or pharmacist about the allergy and what symptoms you had.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take while receiving treosulfan injection. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had seizures, Fanconi anemia (an inherited condition that causes bone marrow failure), skin problems, or kidney disease.
• Treosulfan injection may decrease fertility in men and women. However, you should not assume that you or your partner cannot become pregnant. Tell your doctor if you are pregnant, plan to become pregnant, or if you plan to father a child. If you can become pregnant, you will need to take a pregnancy test before starting treatment and should not become pregnant while you are receiving treosulfan injection. Use effective birth control during your treatment with treosulfan injection and for 6 months after your final dose. If your partner can become pregnant, use birth control to prevent pregnancy during your treatment and for 3 months after your final dose. Talk to your doctor about birth control methods that will work for you. If you or your partner become pregnant while receiving treosulfan injection, call your doctor immediately. Treoslulfan injection may harm the fetus.
• tell your doctor if you are breastfeeding. Your doctor may tell you not to breastfeed during your treatment and for 1 week after your final dose.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are receving treosulfan injection.
• you should know that treosulfan injection may cause skin reactions, especially on the day the medication is given. Keep your skin clean and dry on the days that you receive treosulfan injection. Use a disposable washcloth and clear water to clean areas of your skin that may sweat such as your armpits, groin, or genital area. Do not apply creams or lotions or wear tight clothing. Call your doctor right away if you have any of the following symptoms: itching or redness of the skin, peeling, dry, or cracked skin; or rash.

What SPECIAL DIETARY instructions should I follow?

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

What SIDE EFFECTS can this medicine cause?

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

• nausea
• vomiting
• diarrhea
• sores in the mouth and throat
• stomach pain
• constipation
• headache
• muscle or bone pain
• swelling of the face, arms, hands, feet, ankles, or lower legs
• tiredness

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING or SPECIAL PRECUATIONS sections, and call your doctor immediately:

• pain, itching, redness, swelling, blisters, or sores in the place where the medication was injected
• fast, irregular, or pounding heartbeat

Treosulfan injection may increase the risk that you will develop other cancers. Talk to your doctor about the risks of receiving this medication.

Treosulfan injection may cause other side effects. Call your doctor if you have any unusual problems while taking 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).

What should I do in case of OVERDOSE?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at http://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:

• vomiting
• diarrhea
• sores in the mouth and throat
• unusual bruising or bleeding; black, tarry, or bloody stools; bloody vomit or vomited material that looks like coffee grounds
• sore throat, cough, fever, or other signs of infection

What OTHER INFORMATION should I know?

Before having any laboratory test, tell your doctor and the laboratory personnel that you are receiving treosulfan injection.

Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines, vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS^® Patient Medication Information™ Copyright, 2025. The American Society of Health-System Pharmacists^®, 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: June 15, 2025.