Reblozyl is a brand-name injection prescribed for anemia in adults with certain blood disorders. Reblozyl contains the active ingredient luspatercept-aamt.

The Food and Drug Administration (FDA) has approved Reblozyl to treat anemia (low red blood cell count) in adults with certain blood disorders. Specifically, it’s used for adults with:

For these uses, people with these conditions need or may need regular red blood cell transfusions. For more details about the approved uses of Reblozyl, see the “Reblozyl uses” section.

Note: Reblozyl is not used to in place of red blood cell transfusions in people who need their anemia corrected right away.

Drug details

Here is key information about Reblozyl.

  • Drug class: erythroid maturation agent
  • Drug form: subcutaneous injection
  • Generic or biosimilar available? no
  • Prescription required? yes
  • Controlled substance? no
  • Year of FDA approval:
    • anemia caused by beta thalassemia: 2019
    • anemia caused by certain types of MDS: 2020

Reblozyl is a biologic drug that’s available only as a brand-name medication. A biologic is a drug that’s made using living cells. Reblozyl is not currently available in generic or biosimilar form.

A generic drug is an exact copy of the active drug in a brand-name medication. A biosimilar drug is a drug that’s similar to the active drug in a brand-name biologic medication. (It’s not possible to produce exact copies of biologic medications.)

Generics and biosimilars are considered to be just as safe and effective as the brand-name drug they’re based on. They usually cost less than brand-name drugs.

The Food and Drug Administration (FDA) approves prescription drugs such as Reblozyl to treat certain conditions. Reblozyl may also be used off-label for other conditions. Off-label drug use means using a drug for a purpose other than what the FDA has approved it for.

Reblozyl for anemia caused by beta thalassemia

Reblozyl is FDA approved to treat anemia (low red blood cell count) in adults with beta thalassemia who need regular red blood cell transfusions.

About beta thalassemia and anemia

Beta thalassemia is an inherited blood disorder (passed down through genes). With beta thalassemia, red blood cells don’t make hemoglobin correctly due to certain gene changes called mutations. (Hemoglobin is the molecule in red blood cells that moves oxygen around the body.)

As a result, the body produces less hemoglobin. This triggers certain signals that stop immature red blood cells from becoming mature red blood cells.

The immature red blood cells build up in the bone marrow, leaving less space for healthy red blood cells to develop and mature. Because of this, people with beta thalassemia have low levels of red blood cells and hemoglobin in their blood.

Anemia can cause symptoms such as:

  • tiredness
  • weakness
  • dizziness
  • shortness of breath
  • fast heartbeat
  • difficulty concentrating
  • skin, gums, or nail beds that are paler than usual
  • leg cramps
  • headache

People with beta thalassemia may have mild or severe anemia. This depends on whether they inherit certain gene mutations from one or both parents.

Having regular red blood cell transfusions adds more red blood cells to the blood. It increases the levels of red blood cells and treats anemia. However, because red blood cells are rich in iron, it can also lead to a buildup of iron in organs such as the liver, heart, or spleen. Treatments called chelating agents are then needed to remove the excess iron.

About Reblozyl for anemia caused by beta thalassemia

Reblozyl increases levels of red blood cells. This enables healthy red blood cells to mature in the bone marrow. This treats anemia without increasing iron levels.

Note: Reblozyl is not used in place of red blood cell transfusions in people who need their anemia corrected right away.

Effectiveness for anemia caused by beta thalassemia

Clinical trials have found Reblozyl to be an effective treatment for anemia in adults with beta thalassemia who need regular red blood cell transfusions. The drug has been shown to reduce the number of red blood cell transfusions needed by people with this condition.

To find out how Reblozyl performed in clinical trials, see the drug’s prescribing information.

Reblozyl for anemia caused by myelodysplastic syndrome

Reblozyl is also FDA approved to treat anemia (low red blood cell count) in adults with certain types of myelodysplastic syndrome (MDS).

About MDS and anemia

MDS is a group of cancers that affect bone marrow and blood cells. Blood cells usually develop from stem cells in bone marrow (the spongy tissue inside your bones). However, with MDS, stem cells become abnormal and don’t develop into mature blood cells. Instead, they develop into immature blood cells called blasts.

This results in decreased levels of one or more types of blood cells, particularly red blood cells. This causes anemia. (For a list of anemia symptoms, see “Reblozyl for anemia caused by beta thalassemia” in the previous section.)

About Reblozyl for anemia caused by MDS

Reblozyl is FDA approved to treat anemia in people with MDS who have not used a drug called an erythropoiesis stimulating agent (ESA) to treat anemia. (This is referred to as being ESA naive.) People with this MDS may need regular red blood cell transfusions.

Reblozyl is also approved to treat anemia caused by MDS in people who have used an ESA that didn’t work for their anemia, and they required two or more red blood cell units over 8 weeks. They also need regular red blood cell transfusions. In this case, Reblozyl is approved to treat:

  • MDS with ring sideroblasts (MDS-RS). Ring sideroblasts are immature red blood cells that contain excess iron.
  • Myelodysplastic/myeloproliferative neoplasms with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T). With thrombocytosis, your body has too many platelets.

In addition to the preceding criteria, the MDS must have a very low to intermediate risk of developing into leukemia. Most people with MDS have a low risk of the condition progressing in this way. Your doctor will determine the risk level of your MDS.

Reblozyl increases levels of red blood cells. Then, more healthy red blood cells are able to mature in the bone marrow. This treats anemia without increasing iron levels, which can happen from having red blood cell transfusions.

Note: Reblozyl is not used in place of red blood cell transfusions in people who need their anemia corrected right away.

Effectiveness for anemia caused by MDS

Reblozyl is an effective treatment for anemia in adults with the types of MDS just described. The drug has been shown to help reduce the need for red blood cell transfusions in people with MDS. To find out how Reblozyl performed in clinical trials, see the drug’s prescribing information.

Guidelines from the National Comprehensive Cancer Network include Reblozyl as a treatment option for anemia caused by certain types of MDS.

Reblozyl and children

Reblozyl is not approved for use in children. It is unknown whether Reblozyl is safe or effective in children.

If you have a child with MDS or beta thalassemia, talk with their doctor about their treatment options.

As with all medications, the price of Reblozyl can vary. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

It’s important to note that only your doctor or a healthcare professional can order Reblozyl. It’s only given at places like your doctor’s office, an infusion clinic, or a similar healthcare setting. You won’t be able to pick up Reblozyl at the pharmacy.

Before approving coverage for Reblozyl, your insurance company may require you to get prior authorization. This means that your doctor and insurance company will need to communicate about your prescription before the insurance company will cover the drug. The insurance company will review the prior authorization request and decide whether it will cover the drug.

If you’re not sure whether you’ll need to get prior authorization for Reblozyl, contact your insurance company.

Financial and insurance assistance

If you need financial support to pay for Reblozyl, or if you need help understanding your insurance coverage, help is available.

The manufacturer of Reblozyl offers a program called BMS Access Support that may help lower your cost for Reblozyl. For more information and to find out if you’re eligible for support, call 800-861-0048 or visit the manufacturer website.

Learn more about saving money on prescription medications.

Generic or biosimilar version

Reblozyl is not available in generic or biosimilar form.

A generic drug is an exact copy of the active drug in a brand-name medication. A biosimilar drug is a drug that’s similar to the active drug in a brand-name biologic medication. Biologic drugs are made using living cells. It’s not possible to produce exact copies of biologic medications.

Generics and biosimilars are considered to be just as safe and effective as the brand-name drug they’re based on. They tend to cost less than brand-name drugs.

The Reblozyl dosage your doctor prescribes will depend on several factors. These include:

  • your body weight in kilograms (kg)
  • the level of hemoglobin in your blood
  • the number of red blood cell transfusions you need

Your doctor may adjust your dosage over time to reach the amount that’s right for you. They’ll ultimately prescribe the smallest dosage that provides the desired effect.

The following information describes dosages that are commonly used or recommended. However, your doctor will determine the best dosage to fit your needs.

Drug forms and strengths

Reblozyl is administered by subcutaneous injection. A healthcare professional will give you the injection in their office or clinic.

Reblozyl comes as a powder in a single-dose vial. It’s available in two strengths: 25 milligrams (mg) and 75 mg. Your healthcare professional will mix the powder with sterile water, measure the correct dose, and give the injection.

Dosage for anemia caused by beta thalassemia or myelodysplastic syndrome

The usual starting dose for adults with anemia caused by beta thalassemia or myelodysplastic syndrome (MDS) is 1 mg per kg (mg/kg) of body weight. This is usually given once every 3 weeks.

Your doctor will check your hemoglobin level before each dose and adjust your dose if needed. Reblozyl is meant to reduce the number of red blood cell transfusions you need. If the number of red blood cell transfusions you need doesn’t decrease after two injections of Reblozyl at the starting dose, your doctor may increase your dose. They’ll decide the dosage that’s right for you at each appointment.

The maximum dosage for anemia caused by beta thalassemia is 1.25 mg/kg, given once every 3 weeks.

The maximum dosage for anemia caused by MDS is 1.75 mg/kg, given once every 3 weeks.

If the number of red blood cell transfusions you need doesn’t decrease after receiving three injections of Reblozyl at the maximum dose, it’s likely that this drug doesn’t work for you. In this case, you’ll need to stop using Reblozyl. Your doctor can recommend alternative treatments to help manage your anemia.

What if I miss a dose?

If you miss an appointment to have a dose of Reblozyl, call your doctor’s office right away to reschedule. You should get the missed dose as soon as possible. You’ll then receive your next dose after 3 weeks, with subsequent doses at least 3 weeks apart.

To help make sure that you don’t miss an appointment for your Reblozyl dose, try setting a reminder on your phone.

Will I need to use this drug long term?

Reblozyl is meant to be used as a long-term treatment. If you and your doctor determine that Reblozyl is safe and effective for you, you’ll likely receive it long term.

Reblozyl can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while receiving Reblozyl. These lists do not include all possible side effects.

For more information about the possible side effects of Reblozyl, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may concern or bother you.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs it has approved. If you would like to notify the FDA about a side effect you’ve had with Reblozyl, you can do so through MedWatch.

Mild side effects

Mild side effects of Reblozyl can include:

This is a partial list of mild side effects from Reblozyl. To learn about other mild side effects, talk with your doctor or pharmacist or view Reblozyl’s prescribing information.

Most of these side effects may go away within a few days or a couple of weeks. However, if they become more severe or don’t go away, talk with your doctor or pharmacist.

Serious side effects

Serious side effects from Reblozyl aren’t common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 or your local emergency number if your symptoms feel life threatening or you think you’re having a medical emergency.

Serious side effects and their symptoms can include:

For more information about some of these serious side effects, see the “Side effect details” section next.

Side effect details

Here’s some detail on certain side effects this drug may cause.

Blood clots

There may be a small risk of blood clots forming in the veins or arteries with Reblozyl treatment. This side effect wasn’t common in clinical trials of the drug, but it can be serious.

In trials, blood clots were reported in some people who took Reblozyl to treat anemia caused by beta thalassemia. The types of blood clots reported include:

Also, there were reports of ischemic stroke (stroke caused by a clot in the brain) occurring in clinical trials of Reblozyl.

To find out how often these side effects occurred in clinical trials, see Reblozyl’s prescribing information.

Symptoms of a blood clot may include:

  • pain or swelling in your leg
  • cold or pale arm or leg
  • chest pain
  • difficulty breathing
  • pain or swelling in your abdomen
  • sudden weakness or numbness on one side of your body
  • sudden headache or confusion
  • sudden difficulty talking, seeing, or walking

You may have a higher risk of blood clots with Reblozyl if you’ve had your spleen removed or had a blood clot in the past. You may also have a higher risk if you smoke or take certain medications. These include birth control pills and hormone replacement therapy.

If your doctor thinks you have a high risk of blood clots with Reblozyl, they may prescribe medication to help prevent this side effect.

If you have symptoms of a blood clot during your Reblozyl treatment, talk with your doctor right away. However, if your symptoms feel life threatening or you think you’re having a medical emergency, call 911 or your local emergency number.

If you have a blood clot, you’ll typically need to stop receiving Reblozyl until it’s been treated.

Hypertension

You may develop hypertension (high blood pressure) during Reblozyl treatment. This side effect was commonly reported in clinical trials of the drug. To find out how often this side effect occurred in trials, see Reblozyl’s prescribing information.

High blood pressure doesn’t usually cause symptoms. However, it can increase your risk of heart attack or stroke.

Your doctor will check your blood pressure before you receive each dose of Reblozyl. If your blood pressure is too high, your doctor may delay treatment until your blood pressure is managed. Your doctor may also prescribe medication to help lower your blood pressure. If you already take blood pressure medication, your doctor may increase your dose.

Allergic reaction

As with most drugs, some people can have an allergic reaction after receiving Reblozyl.

Symptoms of a mild allergic reaction can include:

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include:

  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your tongue, mouth, or throat
  • difficulty breathing

Call your doctor right away if you have an allergic reaction to Reblozyl, as the reaction could become severe. Call 911 or your local emergency number if your symptoms feel life threatening or you think you’re having a medical emergency.

Reblozyl is used to treat anemia (low red blood cell count) in adults with certain blood disorders. Specifically, it’s used for adults with:

Reblozyl helps increase red blood cell count in adults with these conditions.

What happens with beta thalassemia

With beta thalassemia, inherited gene mutations (changes) stop immature red blood cells from making hemoglobin correctly. (Hemoglobin is the molecule in red blood cells that moves oxygen around the body.)

As a result, the body produces less hemoglobin. This triggers certain signals that stop immature red blood cells from maturing.

The immature red blood cells build up in the bone marrow, leaving less space for healthy red blood cells to develop and mature. Because of this, people with beta thalassemia have low levels of red blood cells and hemoglobin in their blood.

What happens with myelodysplastic syndrome

With MDS, your stem cells develop an abnormality that stops them from developing into mature blood cells. Instead, they develop into immature blood cells called blasts.

The blasts build up in the bone marrow, leaving less space for healthy blood cells to develop and mature. Because of this, people with MDS have low levels of one or more types of blood cells, particularly red blood cells.

What Reblozyl does

Reblozyl’s mechanism of action (the way it works) for treating anemia is to increase your levels of red blood cells. It does so by helping more healthy red blood cells mature in your bone marrow. This reduces the number of red blood cell transfusions you may need to treat anemia.

How long does it take to work?

Reblozyl typically starts to work about a week after your first injection. However, it may take a few weeks before you need fewer red blood cell transfusions. Your doctor will monitor how well the treatment is working for you by checking your hemoglobin and red blood cell levels.

If you have questions about when you should see results from Reblozyl, talk with your doctor.

Reblozyl is administered by subcutaneous injection. A healthcare professional will give you the injection in their office or clinic.

They may give the injection in your upper arm, thigh, or abdomen.

When it’s given

Reblozyl is usually given once every 3 weeks.

To help make sure that you don’t miss an appointment for your Reblozyl dose, try setting an alarm or timer on your phone or downloading a reminder app.

Reblozyl is not known to interact with alcohol. However, if you have certain side effects with Reblozyl, such as headache, dizziness, diarrhea, or nausea, drinking alcohol could make this worse.

If you drink alcohol, talk with your doctor about how much is safe for you to drink during Reblozyl treatment.

Reblozyl can interact with several other medications.

Different interactions can cause different effects. For instance, some interactions can interfere with how well a drug works. Other interactions can increase side effects or make them more severe.

Reblozyl and other medications

Here is a list of medications that can interact with Reblozyl. This list does not contain all drugs that may interact with Reblozyl.

Before starting Reblozyl treatment, talk with your doctor or pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also, tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

If you have questions about drug interactions that may affect you, talk with your doctor or pharmacist.

Types of drugs that can interact with Reblozyl include:

  • Birth control pills: Reblozyl can sometimes cause blood clots. You may have a higher risk of this side effect if you take birth control pills with Reblozyl. Examples include:
    • ethinyl estradiol/desogestrel (Apri, Azurette, Kariva, Reclipsen)
    • ethinyl estradiol/drospirenone (Loryna, Ocella, Syeda, Yasmin, Yaz, Zarah)
    • ethinyl estradiol/levonorgestrel (Aviane, Lessina, Levora, Lutera, Portia, Sronyx)
    • ethinyl estradiol/norethindrone (Balziva, Junel, Loestrin, Nortrel, Ortho-Novum)
    • ethinyl estradiol/norgestimate (Ortho-Cyclen, Previfem, Sprintec)
  • Hormone replacement therapy (HRT): Reblozyl can sometimes cause blood clots. You may have a higher risk of this side effect if you take HRT with Reblozyl. Examples of HRT medications include:
    • estradiol/drospirenone (Angeliq)
    • estradiol/levonorgestrel (Climara Pro)
    • estradiol/norethindrone (Activella, Amabelz)
    • estradiol/norgestimate (Prefest)
    • estradiol/progesterone (Bijuva)
    • ethinyl estradiol/norethindrone (Jinteli)
    • estradiol patch (Climara, Minivelle, Vivelle-Dot)
    • oral estrogen (Premarin)
    • estrogen/methyltestosterone (Covaryx)
    • estrogen/bazedoxifene (Duavee)
    • estrogen/medroxyprogesterone (Prempro, Premphase)

Reblozyl and herbs and supplements

There aren’t any herbs or supplements that have been specifically reported to interact with Reblozyl. However, you should still check with your doctor or pharmacist before using any of these products while receiving Reblozyl.

Reblozyl and foods

No foods have been specifically reported to interact with Reblozyl. If you have any questions about eating certain foods with Reblozyl, talk with your doctor.

Reblozyl is not safe to receive during pregnancy. The drug hasn’t been studied in pregnant people. However, it’s expected to cause fetal harm if used during pregnancy. This is based on the way the drug works and findings from animal studies.

If you can become pregnant, you’ll need to have a pregnancy test before you start Reblozyl. This is so your doctor can be sure you’re not pregnant before giving you the drug.

If you’re pregnant or planning to become pregnant, talk with your doctor about other treatment options. And if you think you could be pregnant while receiving Reblozyl, tell your doctor right away.

Reblozyl and fertility

Reblozyl may affect your ability to become pregnant. Animal studies found the drug temporarily reduced female fertility. In these studies, male fertility was not affected by the drug. However, animal studies do not always predict what will happen in humans.

If you’re concerned about the possible effect of Reblozyl on your fertility, talk with your doctor.

Note: Sex and gender exist on spectrums. Use of the terms “male” and “female” in this article refers to sex assigned at birth.

Reblozyl is not safe to receive during pregnancy. If you’re sexually active and you or your partner can become pregnant, talk with your doctor about your birth control needs during Reblozyl treatment.

For more information about receiving Reblozyl during pregnancy, see the “Reblozyl and pregnancy” section.

For females using Reblozyl

Females should use effective birth control during treatment with Reblozyl and for 3 months after the last dose.

For males using Reblozyl

The manufacturer of Reblozyl hasn’t given birth control recommendations for males using the drug. If you’re a male using Reblozyl and you have a partner who can become pregnant, talk with your doctor about your birth control needs during treatment.

Note: Sex and gender exist on spectrums. Use of the terms “male” and “female” in this article refers to sex assigned at birth.

You shouldn’t breastfeed during treatment with Reblozyl and for 3 months after your last dose.

It is unknown whether Reblozyl passes into human breast milk. However, if it does get into breast milk, it has the potential to cause serious side effects in a child who is breastfed.

If you’re breastfeeding or planning to breastfeed, talk with your doctor before using Reblozyl.

Here are answers to some frequently asked questions about Reblozyl.

Will Reblozyl cure my condition?

No, Reblozyl won’t cure the cause of your anemia.

Reblozyl helps increase your red blood cell count. It can lessen anemia that’s caused by beta thalassemia or myelodysplastic syndrome (MDS). However, it can’t cure the conditions that cause anemia. And anemia that’s caused by beta thalassemia or MDS can come back after you stop Reblozyl.

How will I know if Reblozyl is working for me?

There are a few things that can show whether Reblozyl is working for you:

  • You may notice that your anemia symptoms start to decrease. For example, you may feel less tired or breathless.
  • You may need fewer red blood cell transfusions.
  • Blood tests may show that your hemoglobin level has increased.

If the number of red blood cell transfusions you need does not decrease after getting three maximum doses of Reblozyl, it’s likely that this drug doesn’t work for you. If that’s the case, you’ll need to stop using Reblozyl. Your doctor will recommend other treatment options to help manage your anemia.

What can I do to help prevent a blood clot during my Reblozyl treatment?

There are a few ways to help prevent blood clots during your Reblozyl treatment. These include not smoking, keeping active, and reaching or maintaining a moderate body weight.

Certain medications, such as birth control pills and hormone replacement therapy, can also increase your risk of blood clots. If you take one of these medications, talk with your doctor about possible alternatives.

If you have certain factors that raise your risk of blood clots with Reblozyl, your doctor may talk with you about taking blood thinners. These are medications that can help prevent blood clots.

In clinical trials, blood clots were reported in a few people with beta thalassemia who took Reblozyl. To read more about this side effect, see the “Reblozyl side effects” section.

Before starting Reblozyl treatment, talk with your doctor about your health history. 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:

  • risk of blood clots, such as smoking or a history of blood clots
  • hypertension (high blood pressure)
  • previous allergic reaction to this or a similar drug
  • spleen removal
  • enlarged spleen or liver
  • history of extramedullary hematopoietic masses
  • low hemoglobin level
  • pregnancy
  • breastfeeding

Note: For more information about the potential negative effects of Reblozyl, see the “Reblozyl side effects” section.

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.

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