Reblozyl (luspatercept-aamt) is a prescription drug that’s used to treat anemia from certain blood conditions. Reblozyl is given as an injection under your skin by a doctor or other healthcare professional.

Reblozyl is used in adults to treat anemia from certain blood conditions, such as:

To learn more about Reblozyl’s uses, see the “What is Reblozyl used for?” section below.

Reblozyl basics

Reblozyl contains the active ingredient luspatercept-aamt. Reblozyl is a biologic medication. A biologic is made from parts of living organisms. Reblozyl is available as a brand-name drug only. It isn’t available in a biosimilar form.

Biosimilars are like generic drugs. But unlike generics, which are made for non-biologic drugs, biosimilars are made for biologic drugs.

Biosimilars will have the same active ingredient core name as the brand-name drug. But they’ll have unique suffixes. This is why “-aamt” appears at the end of the name of the active ingredient. This is to show that it’s distinct from biosimilars that may be created in the future.

Like most drugs, Reblozyl may cause mild to serious side effects. The lists below describe some of the more common side effects this drug may cause. These lists don’t include all possible side effects.

Keep in mind that side effects of a drug can depend on:

  • your age
  • other health conditions you have
  • other medications you take

Your doctor or pharmacist can tell you more about the potential side effects of Reblozyl. They can also suggest ways to help reduce side effects.

Mild side effects

Below is a list of some of the mild side effects that Reblozyl can cause. Side effects may differ slightly between people with beta thalassemia and people with certain myelodysplastic syndromes. To learn about other mild side effects, talk with your doctor or pharmacist, or read Reblozyl’s prescribing information.

Mild side effects of Reblozyl that have been reported include:

Mild side effects of many drugs may go away within a few days to a couple of weeks. But if they become bothersome, talk with your doctor or pharmacist.

* To learn more about this side effect, see the “Allergic reaction” section below.

Serious side effects

Serious side effects from Reblozyl can occur. If you have serious side effects from Reblozyl, call your doctor right away. But if you think you’re having a medical emergency, you should call 911 or your local emergency number.

Side effects may differ slightly between people with beta thalassemia and people with certain myelodysplastic syndromes. Serious side effects of Reblozyl that have been reported include:

* You may have a higher risk of this side effect if you’re also taking birth control pills or hormone replacement or if you’ve had your spleen removed.

† Extramedullary hematopoietic masses occur when your bone marrow doesn’t make enough of certain types of blood cells. This may cause masses on certain organs, such as your spleen or liver. You’re at a higher risk of this side effect if you’ve had them before or have had your spleen removed.

Allergic reaction

Some people may have an allergic reaction to Reblozyl.

Symptoms of a mild allergic reaction can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include swelling under your skin, usually in your eyelids, lips, hands, or feet. They can also include swelling of your tongue, mouth, or throat, which can cause trouble breathing.

Call your doctor right away if you have an allergic reaction to Reblozyl. But if you think you’re having a medical emergency, call 911 or your local emergency number.

Your doctor will recommend the dosage of Reblozyl that’s right for you. Below are commonly used dosages, but the dosage you receive will be determined by your doctor.

To learn more about Reblozyl’s dosage, see this article.

Form and strengths

Reblozyl is given as an injection under the skin by your doctor or another healthcare professional. The drug is available in two strengths: 25 milligrams (mg) and 75 mg.

Recommended dosages

Your doctor will prescribe a starting Reblozyl dosage based on your body weight in kilograms (kg).* This starting dosage is usually 1 mg per kg injected once every 3 weeks. You’ll receive your dose in a doctor’s office or a clinic.

Your doctor will likely adjust your Reblozyl dosage based on your hemoglobin level and your need for red blood cell transfusions (RBCTs) between doses. Before giving each dose, your doctor will check your hemoglobin level. Depending on your level, they may adjust your dose or temporarily stop your treatment.

* One kg is approximately equal to 2.2 pounds (lb).

For anemia from beta thalassemia:

  • If your need for RBCTs hasn’t decreased after at least two doses of 1 mg/kg injected every 3 weeks, your doctor may increase your dosage to 1.25 mg/kg given every 3 weeks.
  • If your need for RBCTs hasn’t decreased after three doses of 1.25 mg/kg (9 weeks of treatment), your doctor may choose to stop your Reblozyl treatment completely.
  • If you develop side effects, your doctor may also choose to pause or stop your Reblozyl treatment.

For anemia from myelodysplastic syndromes:

  • If you continue to require RBCTs after two doses of 1 mg/kg injected every 3 weeks, your doctor may increase your dosage to 1.33 mg/kg injected every 3 weeks.
  • If you continue to need RBCTs after two consecutive doses of 1.33 mg/kg, the dosage can be increased to 1.75 mg/kg injected every 3 weeks.
  • If your need for RBCTs still hasn’t decreased after three doses of 1.75 mg/kg (9 weeks), your doctor will likely stop your Reblozyl treatment.
  • If you develop side effects, your doctor may also choose to pause or stop your Reblozyl treatment.

How it’s given

Your doctor will explain how Reblozyl will be given to you. They’ll also explain how much you’ll receive and how often.

Reblozyl is given as an injection under the skin. You’ll receive Reblozyl injections into your thigh, belly, or upper arm.

Questions about receiving Reblozyl

Below are some common questions about receiving Reblozyl.

  • What if I miss a dose of Reblozyl? If you miss an appointment to receive an injection of Reblozyl, call your doctor’s office as soon as possible to reschedule. Once you receive your missed dose, your doctor can adjust your dosage schedule as needed to make sure there are at least 3 weeks between doses.
  • Will I need to use Reblozyl long term? Reblozyl is typically used as a long-term treatment. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely take it long term.

Whether you have health insurance or not, cost may be a factor when you’re considering Reblozyl. What you’ll pay for Reblozyl may depend on several things, such as your treatment plan.

If you have questions about how to pay for your prescription, talk with your doctor or pharmacist. A program called Celegene Patient Support may also be available.

You can also check out this article to learn more about saving money on prescriptions.

Reblozyl is used in adults to treat anemia from certain types of blood conditions, such as:

See below for details.

Beta thalassemia: Reblozyl is used to treat anemia in people who have beta thalassemia and regularly need red blood cell transfusions (RBCTs). Beta thalassemia is a genetic (inherited) condition. Gene imbalances cause your body to make lower amounts of hemoglobin. (Hemoglobin helps your red blood cells carry oxygen through your body.)

Myelodysplastic syndromes: If you have this condition, you may be prescribed Reblozyl if you need regular RBCTs and haven’t taken an erythropoietin-stimulating agent (ESA) before. Your doctor may also prescribe the drug if you have this condition and have tried an ESA before, but it wasn’t effective for your anemia and you still need at least two units of RBCT in 8 weeks.

Myelodysplastic syndromes are types of blood cancer that cause anemia.

Anemia occurs when your body doesn’t make enough red blood cells. It may cause a range of symptoms, including:

  • pale skin, gums, or nails
  • cold hands and feet
  • unusual cravings, such as having the urge to eat ice or dirt

Reblozyl works to treat anemia from these conditions by increasing the amount of red blood cells you have. It also helps these cells circulate through your body properly.

Reblozyl is not used as a substitute for RBCT if you need more urgent treatment for anemia.

Below is important information you should consider before starting Reblozyl treatment.

Interactions

Combining a drug with certain medications, vaccines, foods, and other things can affect how the drug works. These effects are called interactions.

Reblozyl is not known to interact with other medications, herbs, supplements, foods, or alcohol. The manufacturer did not list any interactions in the drug’s prescribing information.

Before starting Reblozyl treatment, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also, tell them about any vitamins, herbs, and supplements you take. 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.

Pregnancy and breastfeeding

Reblozyl is not safe to receive during pregnancy. If you can become pregnant, your doctor will likely have you take a pregnancy test to make sure you’re not pregnant before you start Reblozyl treatment.

Reblozyl also is not safe to receive while breastfeeding. You should not breastfeed during your Reblozyl treatment and for 3 months after your last dose.

If you’re pregnant or breastfeeding, or planning to become pregnant or to breastfeed, talk with your doctor before starting Reblozyl treatment.

Birth control

If you’re able to become pregnant, you should use birth control throughout your Reblozyl treatment and for 3 months after your last dose.

Warnings

Reblozyl can sometimes cause harmful effects in people who have certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Reblozyl is a good treatment option for you.

Talk with your doctor about your health history before you take Reblozyl. Be sure to tell them if any of the following factors apply to you:

If you have beta thalassemia, tell your doctor if any of the following apply to you:

  • you’ve had a blood clot before
  • you have a higher risk of developing a blood clot, such as taking hormone replacement therapy or having had your spleen removed
  • you’ve had extramedullary hematopoietic (EMH) masses before
  • you have a higher risk of EMH, such as having an enlarged spleen or liver or having had your spleen removed

Find answers to some commonly asked questions about Reblozyl.

How long does it take Reblozyl to start working?

Your doctor will monitor your hemoglobin levels and need for red blood cell transfusions (RBCT) while you take Reblozyl to gauge how the drug is working for you. Within a few weeks of starting Reblozyl treatment, you should need fewer RBCTs. But if your need for RBCTs isn’t decreased after 9 weeks of receiving Reblozyl, your doctor will likely stop your treatment.

Will Reblozyl cure my condition?

No, Reblozyl does not cure anemia from beta thalassemia or certain myelodysplastic syndromes. There’s currently no cure for these conditions. However, Reblozyl works to manage the symptoms of anemia from these conditions.

If you have other questions about what to expect from your Reblozyl treatment, talk with your doctor.

If you have questions about Reblozyl treatment, talk with your doctor or pharmacist. Questions you may want to ask include:

  • If I can’t afford Reblozyl, what other treatment options are available?
  • What should I do if I become pregnant during my Reblozyl treatment?
  • If my Reblozyl treatment has to be paused because I develop side effects, how long should I expect this pause to last?

To learn more about Reblozyl, see these articles:

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Disclaimer: Healthline 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.