Idhifa (enasidenib) is a prescription brand-name medication. It’s approved by the Food and Drug Administration (FDA) to treat a type of relapsed or refractory acute myeloid leukemia (AML)* in adults.

It’s typically recommended to take Idhifa for at least 6 months. However, you’ll likely continue taking the drug for as long as it’s effective or not causing intolerable side effects.

Here are some fast facts about Idhifa:

  • Active ingredient: enasidenib
  • Drug class: isocitrate dehydrogenase-2 (IDH2) inhibitor
  • Drug form: oral tablet
  • FDA approval year: 2017

As with other drugs, Idhifa can cause side effects. Read on to learn about potential common, mild, and serious side effects. For a general overview of Idhifa, including details about its uses, see this article.

* Idhifa is approved to treat AML that has a mutation (abnormal change) in the IDH2 gene. “Relapsed” means the cancer has returned after past treatment. “Refractory” means the cancer is not responding to treatment.

Idhifa 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 Idhifa in clinical trials:

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

Mild side effects that have been reported with Idhifa include:

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

These side effects may be temporary, lasting a few days to weeks. However, if the side effects 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 side effects of the medication. If you develop a side effect while taking Idhifa and want to report it to the FDA, visit MedWatch.

Idhifa 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 Idhifa’s prescribing information.

If you develop serious side effects while taking Idhifa, 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:

* For more information about this side effect, see “Side effect specifics” below.
Idhifa has a boxed warning about the risk of this side effect. This is the most serious warning from the Food and Drug Administration (FDA).
‡ An allergic reaction is possible after taking Idhifa. However, this side effect wasn’t reported in clinical trials.

Idhifa may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Will I have to stop taking Idhifa if I develop differentiation syndrome?

It depends. If you develop differentiation syndrome* (a condition that affects your blood cells and can be life threatening), your doctor will likely prescribe corticosteroids to treat this condition. And you may have to stop taking Idhifa for a period of time if:

  • you need a breathing tube or ventilator to help you breathe
  • you have lung or kidney problems that are severe or continue after 48 hours of corticosteroid treatment

If your symptoms improve, your doctor may have you restart Idhifa treatment.

* Idhifa has a boxed warning for risk of differentiation syndrome. This is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Side effect specifics” section below.

Will I need to get certain lab tests done if I have side effects from Idhifa?

It’s likely. You will need to have certain lab tests done before you start taking Idhifa. Then, your doctor will typically recommend more lab tests to monitor how your body is responding to Idhifa. This may include tests to monitor certain side effects if they develop.

Before you start taking Idhifa, your doctor will likely order:

While you’re taking Idhifa, your doctor may order:

  • a CBC and other blood tests every 2 weeks during the first 3 months of treatment
  • other lab tests to check your levels of:

You might have some blood tests more often during treatment if you develop certain side effects, such as changes in blood cell levels.

* Idhifa is approved to treat AML that has a mutation (abnormal change) in the isocitrate dehydrogenase-2 (IDH2) gene, in certain situations.

Are there medications that can make side effects from Idhifa worse?

Yes, possibly. Idhifa can increase or decrease the levels of other medications in your body. This can make side effects from the other drugs worse. Below are some medications that may be affected by Idhifa:

Be sure to let your doctor know about all the medications you take before starting treatment with Idhifa.

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

Leukocytosis

Idhifa may cause leukocytosis (increased white blood cell levels). In clinical trials, this was a common side effect.

Before you start taking Idhifa, you’ll have blood tests to make sure your blood cell levels are healthy. You’ll continue to have these tests during Idhifa treatment.

Leukocytosis sometimes doesn’t cause noticeable symptoms, but your doctor will monitor your blood test results. If symptoms do occur, they can include fever, fatigue, night sweats, and trouble breathing.

If your white blood cell levels increase, your doctor might prescribe a drug called Hydrea (hydroxyurea) to lower them. If this drug doesn’t decrease your white blood cell counts, you may need to stop taking Idhifa temporarily. Once your blood cell levels return to normal, your doctor may have you restart Idhifa.

What you can do

Be sure to get regular blood tests during Idhifa treatment, as recommended by your doctor. You can also talk with your doctor if you have concerns about leukocytosis.

Increased bilirubin

Increased levels of bilirubin in the blood was a common side effect in Idhifa’s clinical trials.

Bilirubin is a substance that forms when red blood cells break down. Having a high bilirubin level may cause jaundice (yellowing of the skin and the whites of the eyes). Jaundice can also cause dark urine and itchiness.

What you can do

Tell your doctor if you notice any yellowing of your skin or eyes while taking Idhifa. They may recommend lab tests to check your bilirubin level. And they might lower your dosage of Idhifa until your bilirubin level returns to normal.

Digestive side effects

Idhifa commonly causes digestive side effects. These include:

These side effects can be mild or severe. Severe nausea, vomiting, or diarrhea can lead to dehydration.

What you can do

Tell your doctor if you have digestive side effects from Idhifa. And be sure to tell them right away if you have vomiting or diarrhea that is severe. Your doctor may recommend eating a bland diet and drinking beverages that contain electrolytes. They may also recommend certain medications to manage your side effects.

Differentiation syndrome

Idhifa has a boxed warning about the risk of differentiation syndrome. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It alerts patients and doctors about drug effects that may be dangerous.

Differentiation syndrome is a serious side effect that can happen after taking certain cancer drugs, including Idhifa. When cancer treatments break down leukemia cells, there can be a large, rapid release of immune system proteins called cytokines. This can lead to differentiation syndrome, which is a life threatening condition if it’s not treated early.

Symptoms of differentiation syndrome may include:

When differentiation syndrome occurs, it usually develops 1 to 2 weeks after starting Idhifa treatment. However, it can also develop earlier or later in treatment.

What you can do

Tell your doctor right away or go to the nearest emergency room if you start having any of the symptoms listed above. If you have differentiation syndrome, you might need treatment in a hospital until your symptoms improve. Treatment may involve taking corticosteroids to reduce your symptoms.

Allergic reaction

As with most drugs, Idhifa can cause an allergic reaction in some people. But this side effect wasn’t reported in clinical trials.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your lips, eyelids, feet, or hands
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking Idhifa. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

There are some factors for you and your doctor to consider before you start Idhifa treatment. These precautions are described below.

Boxed warning: Differentiation syndrome

This drug has a boxed warning about the risk of differentiation syndrome. This is a serious warning from the Food and Drug Administration (FDA). For details, see the “Side effect specifics” section above.

Other precautions

Be sure to talk with your doctor about your health history before you take Idhifa. This drug may not be the right treatment for you if you have certain medical conditions or other factors that affect your health.

This includes any allergic reactions you’ve had to Idhifa or any of its ingredients. Your doctor will likely not prescribe Idhifa if you’ve had an allergic reaction to the drug before. Ask your doctor what other medications may be better options for you.

Alcohol use with Idhifa

Idhifa isn’t known to interact with alcohol. However, drinking alcohol can make some of the side effects of Idhifa worse. These include nausea, vomiting, and diarrhea. If you drink alcohol, you can talk with your doctor if you have concerns about drinking while taking Idhifa.

Pregnancy and breastfeeding while taking Idhifa

It’s not recommended to take Idhifa during pregnancy, as the drug can harm a fetus.

If you’re able to become pregnant, your doctor will have you take a pregnancy test before prescribing Idhifa. Tell your doctor if you’re pregnant or planning to become pregnant before you start treatment with Idhifa. Also tell them right away if you become pregnant during treatment.

If you or your sexual partner is able to become pregnant, you’ll need to use effective birth control while taking Idhifa. And you should continue using birth control for at least 2 months after your last dose of Idhifa. Talk with your doctor about which forms of birth control are best to use while taking Idhifa. They may recommend nonhormonal methods because Idhifa can affect how well hormonal birth control works.

Treatment with Idhifa can cause mild and serious side effects. Some side effects are rare, and others are more common. See the “Side effect specifics” section above for more information.

If you’d like to learn more about Idhifa, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

  • More information about Idhifa. For details about other aspects of Idhifa, refer to this article.
  • A look at leukemia. For details about your condition, see our cancer hub. You can also find information in our lists of leukemia and cancer and oncology articles.

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.