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Drug Safety-related Labeling Changes (SrLC)

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Safety-related Labeling Changes Approved by FDA Center for Drug Evaluation and Research (CDER)

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07/08/2022 (SUPPL-6)

Approved Drug Label (PDF)

5 Warnings and Precautions

5.3 Extramedullary Hematopoietic Masses

Newly added subsection:

In adult patients with transfusion dependent beta thalassemia, EMH masses were observed in 3.2% of REBLOZYL-treated patients, with spinal cord compression symptoms due to EMH masses occurring in 1.9% of patients (BELIEVE and REBLOZYL long-term follow-up study).

In a study of adult patients with non-transfusion dependent beta thalassemia, a higher incidence of EMH masses was observed in 6.3% of REBLOZYL-treated patients vs. 2% of placebo-treated patients in the double-blind phase of the study, with spinal cord compression due to EMH masses occurring in 1 patient with a prior history of EMH. REBLOZYL is not indicated for use in patients with non-transfusion dependent beta-thalassemia.

Possible risk factors for the development of EMH masses in patients with beta thalassemia include history of EMH masses, splenectomy, splenomegaly, hepatomegaly, or low baseline hemoglobin (<8.5 g/dL). Signs and symptoms may vary depending on the anatomical location. Monitor patients with beta thalassemia at initiation and during treatment for symptoms and signs or complications resulting from the EMH masses and treat according to clinical guidelines. Discontinue treatment with REBLOZYL in case of serious complications due to EMH masses. Avoid use of REBLOZYL in patients requiring treatment to control the growth of EMH masses.

6 Adverse Reactions

Addition of the following to the bulleted line listing:

  • Extramedullary Hematopoietic Masses [see Warnings and Precautions (5.3)]


6.1 Clinical Trials Experience

Additions and/or revisions underlined:

Clinically relevant adverse reactions in <5% of patients include vertigo/vertigo positional, syncope/presyncope, injection site reactions, hypersensitivity, extramedullary hematopoietic masses, and spinal cord compression.

17 PCI/PI/MG (Patient Counseling Information/Patient Information/Medication Guide)


Additions and/or revisions underlined:

Extramedullary Hematopoietic Masses

Advise patients with beta thalassemia of the potential risk of extramedullary hematopoietic masses. Review possible risk factors for developing extramedullary hematopoietic masses. Instruct patients to report possible signs and symptoms of EMH masses [see Warnings and Precautions (5.3)].


Additions and/or revisions underlined:

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

  • have a history of extramedullary hematopoietic (EMH) masses

  • have or have had enlarged spleen or liver

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 get any of these symptoms:

  • Extramedullary Hematopoietic (EMH) Masses. EMH masses have happened in people with beta thalassemia during treatment with REBLOZYL. You may have a higher risk for developing EMH masses if you have a history of EMH masses, have had your spleen removed, have or have had enlarged spleen or liver, or have low hemoglobin levels. Your healthcare provider will monitor you before you start and during treatment with REBLOZYL. Call your healthcare provider or get medical help right away if you get any of these symptoms:

    • severe pain in the back

    • numbness, weakness or loss of voluntary movement in feet, legs, hands or arms

    • loss of bowel and bladder control

For more information, go to www.REBLOZYL.com or call 1-888-423-5436.