For questions about BMS medicines during this time please call 1-800-721-8909.

BMS values your privacy. BMS, its affiliates, and its agents will not sell or rent your personal information.
By providing your information, you acknowledge that you have read and agree to the terms of BMS's Privacy Policy.

  • Let us know what kind of content you're looking for

What is REBLOZYL® (luspatercept-aamt)?

REBLOZYL is a prescription medicine used to treat anemia (low red blood cells) in adults with:

  • beta thalassemia who need regular red blood cell (RBC) transfusions.
  • myelodysplastic syndromes with ring sideroblasts (MDS-RS) or myelodysplastic/myeloproliferative neoplasms with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) who need regular RBC transfusions and have not responded well to or cannot receive an erythropoiesis stimulating agent (ESA).

REBLOZYL is not for use as a substitute for RBC transfusions in people who need immediate treatment for anemia.

It is not known if REBLOZYL is safe or effective in children.

Before receiving REBLOZYL, tell your healthcare provider about all of your medical conditions, including if you:

  • have or have had blood clots
  • have or have had high blood pressure (hypertension)
  • take hormone replacement therapy or birth control pills (oral contraceptives)
  • have had your spleen removed (splenectomy)
  • smoke
  • are pregnant or plan to become pregnant. REBLOZYL may harm your unborn baby. Tell your healthcare provider right away if you become pregnant or think you may be pregnant during treatment with REBLOZYL.
  • Females who are able to become pregnant:

    • Your healthcare provider should do a pregnancy test before you start treatment with REBLOZYL.
    • You should use effective birth control (contraception) during treatment with REBLOZYL and for at least 3 months after the last dose.
  • are breastfeeding or plan to breastfeed. It is not known if REBLOZYL passes into your breast milk.
    • Do not breastfeed during treatment with REBLOZYL and for 3 months after the last dose. Talk to your healthcare provider about the best way to feed your baby during this time.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements

What are the possible side effects of REBLOZYL?

REBLOZYL may cause serious side effects, including:

  • Blood clots. Blood clots in the arteries, veins, brain, and lungs have happened in people with beta thalassemia during treatment with REBLOZYL. The risk of blood clots may be higher in people who have had their spleen removed or who take hormone replacement therapy or birth control (oral contraceptives). Call your healthcare provider or get medical help right away if you have any of these symptoms:
    • chest pain
    • trouble breathing or shortness of breath
    • pain in your leg, with or without swelling
    • a cold or pale arm or leg
    • sudden numbness or weakness that are both short-term or continue to happen over a long period of time, especially on one side of the body
    • severe headache or confusion
    • sudden problems with vision, speech, or balance (such as trouble speaking, difficulty walking, or dizziness)
  • High blood pressure. REBLOZYL may cause an increase in your blood pressure. Your healthcare provider will check your blood pressure before you receive your REBLOZYL dose. Your healthcare provider may prescribe you medicine to treat high blood pressure or increase the dose of medicine you already take to treat high blood pressure, if you develop high blood pressure during treatment with REBLOZYL.

The most common side effects of REBLOZYL include:

  • tiredness
  • headache
  • muscle or bone pain
  • joint pain (arthralgia)
  • dizziness
  • nausea
  • diarrhea
  • cough
  • stomach (abdominal) pain
  • trouble breathing
  • allergic reactions

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.

These are not all of the possible side effects of REBLOZYL. Call your doctor for medical advice about side effects. You are encouraged to report side effects to the FDA at 1-800-FDA-1088 or

Please see full Prescribing Information and Patient Information for REBLOZYL.