Reblozyl (luspatercept-aamt) is used to treat anemia (low red blood cells) in specific patients with beta thalassemia or myelodysplastic syndromes. Reblozyl increases the number of red blood cells (RBC) in the bloodstream by helping immature red blood cells become mature, and this reduces the amount of blood transfusions required.  Reblozyl is an erythroid maturation agent.  

Reblozyl should not be used instead of RBC  blood transfusions in patients who need to have their anemia treated immediately.

Beta thalassemia is a rare inherited blood disease which causes a problem with the production of red blood cells (erythropoiesis). This means that fewer and less healthy red blood cells are produced, resulting in anemia.

In Myelodysplastic syndromes (MDS) which is group of blood cancers, the body cannot make healthy healthy red blood cells, white blood cells and platelets properly. Because of the low number of red blood cells patients become anemic and need to have blood transfusions.

Who can use Reblozyl?

Reblozyl is FDA-approved to treat anemia in adult patients with:

• beta thalassemia who need to have regular red blood cell (RBC) transfusions
• very low- to intermediate-risk myelodysplastic syndromes (MDS) who have anemia without having used previous erythropoiesis stimulating agent use (ESA-naïve), who may require regular red blood cell (RBC) transfusions
• very low- to intermediate-risk myelodysplastic syndromes with ring sideroblasts (MDS-RS) or with myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T), who need to have regular RBC transfusions (2 or more RBC units over 8 weeks) and have not responded well to or cannot receive an erythropoiesis stimulating agent (ESA).

Before using Reblozyl tell your doctor about all your medical conditions or allergies, all medicines you use, and if you are pregnant or breastfeeding.

Thrombosis/Thromboembolism: Increased risk for patients with beta thalassemia. Monitor patients for signs and symptoms of thromboembolic events and institute treatment promptly.

Hypertension: Monitor blood pressure (BP) during treatment, start anti-hypertensive treatment if necessary.

Extramedullary Hematopoietic (EMH) Masses: Increased risk in patients with beta thalassemia. Monitor patients for symptoms and signs or complications resulting from the EMH masses. 

Embryo-Fetal Toxicity: May cause fetal harm. Females of reproductive potential should use of effective contraception.

Reblozyl is injected under the skin (subcutaneous injection), in the upper arm, thigh, or stomach (abdomen) by your healthcare provider, usually once every 3 weeks.

Before each injection, your will need a blood test to check your hemoglobin levels. Be sure to tell your healthcare provider when you last had a blood transfusion.

Reblozyl doses are based on weight. Your dose needs may change if you gain or lose weight.

Your blood pressure will need to be checked often.

You may be given other medications to help control your blood pressure. Keep using this medicine for as long as your doctor has prescribed.

Usual Adult Dose for Anemia in beta thalassemia:

Initial dose: 1 mg/kg subcutaneously once every 3 weeks

If no reduction in red blood cell transfusions after 2 doses (6 weeks), increase to 1.25 mg/kg.

Maximum dose: 1.25 mg/kg

Comments:

• This drug is not a substitute for red blood cell transfusions in the immediate correction of anemia.
• Assess and review hemoglobin prior to each administration; if a red blood cell transfusion occurred prior to dosing, use pretransfusion hemoglobin for dosing purposes.
• If pre-dose hemoglobin is 11.5 g/dL or higher (not related to recent transfusion), delay dose until hemoglobin is 11 g/dL or less.
• If treatment response is lost, search for causative factors (e.g. bleeding event); if typical causes are excluded, increase dose to 1.25 mg.
• Discontinue therapy if no decrease in transfusions is seen after 9 weeks (3 doses) at the maximum dose or unacceptable toxicity occurs (at any time).

Recommended Dosage for Myelodysplastic Syndromes Associated Anemia

Initial dose: 1 mg/kg subcutaneously once every 3 weeks

Comments:

Prior to each dose, review the patient’s hemoglobin and transfusion record. Titrate the dose based on responses. Interrupt treatment for adverse reactions. Discontinue Rebozyl if a patient does not experience a decrease in transfusion burden after 9 weeks of treatment (administration of 3 doses) at the maximum dose level or if unacceptable toxicity occurs at any time.

For more detailed information on Rebozyl dosing and information about Dose Titration for Response, Dosing Modifications for Adverse Reactions etc, click on the link below.

Tell your doctor if you have ever had:

• spleen removal surgery, or have or have had enlarged spleen or liver;
• a stroke or blood clot;
• high blood pressure;
• high cholesterol;
• diabetes;
• if you smoke;
• if you use birth control pills or hormone replacement therapy; or
• have a history of extramedullary hematopoietic (EMH) masses.

Pregnancy

Tell your doctor if you are pregnant or could become pregnant. Reblozyl may harm an unborn baby. If you are able to become pregnant, your healthcare provider should ask you to do a pregnancy test before you start treatment. You should use effective birth control to prevent pregnancy while you are using Reblozyl and for at least 3 months after your last dose.

Reblozyl may cause fertility problems in females. This could affect your ability to become pregnant. Talk to your healthcare provider if this is a concern for you.

Breastfeeding

Do not breastfeed while using this medicine, and for at least 3 months after your last dose. Talk to your healthcare provider about the best way to feed your baby during this time.

You should receive an injection as soon as you can, and then go back to your regular schedule. At least 3 weeks should pass between each injection.

Since Reblozyl is given by a healthcare professional in a medical setting, an overdose is unlikely to occur.

Common Reblozyl side effects

The most common Reblozyl side effects include:

• stomach pain, diarrhea; nausea;
• headache, dizziness;
• feeling tired;
• cough; trouble breathing; 
• muscle pain, bone pain, joint pain: or
• allergic reactions.

Serious Reblozyl side effects

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 caregivers right away if you have:

• severe headache, blurred vision, pounding in your neck or ears;
• signs of a stroke--sudden numbness or weakness (especially on one side of the body), severe headache, slurred speech, balance problems;
• signs of a blood clot in the lung - chest pain, sudden cough, wheezing, rapid breathing, coughing up blood; or
• signs of a blood clot deep in the body - swelling, warmth, or redness in an arm or leg.

Your Reblozyl injections may be delayed or permanently discontinued if you have certain side effects.

Reblozyl may cause fertility problems in females. This could affect your ability to become pregnant. Talk to your healthcare provider if this is a concern for you. See more information below about pregnancy and breastfeeding.

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 Reblozyl, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.