Reblozyl (luspatercept-aamt) is a brand-name injection that’s prescribed for certain types of anemia in adults. As with other drugs, Reblozyl can cause side effects, such as fatigue and headache.

Reblozyl can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Reblozyl in clinical trials:

  • fatigue
  • headache
  • dizziness
  • nausea
  • muscle, bone, or joint pain

Mild side effects can occur with Reblozyl use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Reblozyl’s prescribing information.

Mild side effects that have been reported with Reblozyl include:

  • fatigue
  • headache
  • dizziness
  • abdominal pain
  • nausea
  • diarrhea
  • cough
  • difficulty breathing
  • muscle, bone, or joint pain

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews the side effects of the medication. If you develop a side effect while taking Reblozyl and want to tell the FDA about it, visit MedWatch.

Reblozyl may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Reblozyl’s prescribing information.

If you develop serious side effects while taking Reblozyl, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

  • high blood pressure, which typically doesn’t cause symptoms, but in severe cases, symptoms may include:
    • vision changes
    • chest pain
    • severe headache
    • dizziness
  • blood clots*
  • extramedullary hematopoietic (EMH) masses*

* For more information about this side effect, see “Side effect specifics.”

ALLERGIC REACTION

For some people, Reblozyl can cause an allergic reaction. This was a serious side effect reported in the drug’s clinical trials.

In general, symptoms of an allergic reaction can be mild or serious.

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to Reblozyl, your doctor may recommend taking a different medication instead.

Learn more about some of the side effects that Reblozyl may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Reblozyl.

Blood clots

Blood clots were a serious side effect reported by a small number of people in clinical trials of Reblozyl. Typically, this occurred in people who were given Reblozyl to treat anemia caused by beta-thalassemia (a type of blood disorder).

Blood clots can occur in different areas of the body and may cause the following conditions:

Blood clots may cause the following symptoms:

  • chest pain
  • trouble breathing
  • leg swelling or pain
  • cold or pale arm or leg
  • sudden changes in vision, speech, or balance
  • sudden numbness or weakness happening on one side of the body
  • severe headache or confusion

Certain factors may raise your risk of having a blood clot. These include having your spleen removed or taking hormone medications. Examples include hormone replacement therapy (HRT) and birth control. Smoking and having a history of blood clots can also raise your risk of developing future blood clots.

What you can do

Talk with your doctor about your medical conditions and any medications you take. These include any prescriptions, over-the-counter medications, and supplements. Your doctor may prescribe you medications to help prevent blood clots based on your risk.

Blood clots can be life threatening if left untreated. Talk with your doctor right away if you experience symptoms of a blood clot. If it’s life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

EMH masses

EMH masses were a serious side effect rarely reported in clinical trials of Reblozyl. Typically, they were reported by people who were given Rebolyzl to treat anemia caused by beta-thalassemia. EMH masses are blood cell lumps that develop on the outside of the bone marrow, including organs such as the liver and spleen.

Symptoms of EMH masses include:

Below are certain factors that may increase your risk of developing EMH masses:

People receiving Reblozyl for anemia due to beta-thalassemia and not needing blood transfusions also had a higher risk of developing EMH masses. For this reason, Reblozyl is not approved for use in this group of people.

What you can do

Talk with your doctor about all your medical conditions. They’ll help you decide whether Reblozyl is right for you.

Your doctor will also monitor for symptoms of EMH masses before and during your Reblozyl treatment. If you develop symptoms of possibly having EMH masses, talk with your doctor right away.

Below is important information you should consider before receiving Reblozyl.

Precautions

Before taking Reblozyl, discuss your health history with your doctor. Reblozyl may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

  • blood clots
  • taking hormone medications
  • high blood pressure
  • EMH masses
  • spleen removal
  • enlarged spleen or liver
  • smoking
  • previous allergic reaction to this or a similar drug
  • pregnancy
  • breastfeeding
  • alcohol consumption

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.