Tibsovo (ivosidenib) is a brand-name prescription medication. It’s approved by the Food and Drug Administration (FDA) to treat the following types of cancer in adults in certain situations:

Tibsovo is used for forms of these cancers that have a genetic mutation (abnormal change in a gene) called IDH1. This stands for isocitrate dehydrogenase-1. Your doctor will order tests to determine if your cancer cells have this genetic mutation.

Tibsovo is typically used as a long-term treatment.

Here are some fast facts about Tibsovo:

  • Active ingredient: ivosidenib
  • Drug class: IDH1 inhibitor
  • Drug form: oral tablet
  • FDA approval year: 2018

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

Tibsovo can cause certain side effects, some of which are more common than others. Side effects may vary depending on the condition you’re taking the drug for. These side effects may be temporary, lasting a few days to weeks. 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 Tibsovo in clinical trials:

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

Mild side effects can occur with Tibsovo. Side effects may vary depending on the condition you’re taking the drug for. This list doesn’t include all possible mild side effects of Tibsovo. For more details, you can refer to the medication’s prescribing information.

Mild side effects that have been reported with Tibsovo include:

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

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

Tibsovo may cause serious side effects. They may vary depending on the condition you’re taking the drug for. The list below may not include all possible serious side effects of Tibsovo. For more details, you can refer to the medication’s prescribing information.

If you develop serious side effects while taking Tibsovo, 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 include:

* For more information about this side effect, see the “Side effect specifics” section below.
† Tibsovo has a boxed warning for this side effect. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

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

Can Tibsovo cause any long-term side effects?

Yes, Tibsovo can cause some long-term side effects.

Most of Tibsovo’s side effects ease in a few days to weeks as your body gets used to the medication. Others may improve quickly if your doctor prescribes medication to treat the side effect, reduces your Tibsovo dosage, or stops your Tibsovo treatment.

However, some side effects may persist while you take Tibsovo or after you stop treatment. Guillain-Barré and long QT syndrome are two side effects that may last a long time or be lifelong. (To read more about these side effects, see the “Side effect specifics” section below.)

It’s important to note that taking Tibsovo for a long period of time does not seem to increase the risk of side effects. If you’re concerned about your risk of long-term side effects with Tibsovo, talk with your doctor.

Does Tibsovo cause hair loss?

Tibsovo isn’t known to cause hair loss. This was not reported in clinical trials of the drug.

Hair loss is a common side effect of many other cancer treatments, such as chemotherapy and radiation therapy. If you have had treatment for cancer in the past, you may have some hair loss. Tibsovo should not worsen it.

If you’re concerned about hair loss, talk with your doctor.

What can increase my risk of Tibsovo side effects?

Certain foods, medications, and conditions can increase your risk of side effects from Tibsovo. For example, you should not eat high-fat foods when you take Tibsovo. Foods that are high in fat can raise the level of Tibsovo in your body. This may increase the risk of side effects from the drug.

You can take Tibsovo with or without food. If you take the medication with food, your meal or snack should not contain more than 1,000 calories and 58 grams of fat.

You should also avoid drinking grapefruit juice and eating grapefruit during treatment with Tibsovo. Grapefruit contains substances that can affect the way your body breaks down the drug. The substances can cause Tibsovo to build up in your body. This may increase the risk of side effects from the medication.

In addition, taking certain medications with Tibsovo can increase your risk of side effects from this drug. (To learn more, see this article.) Before you start Tibsovo treatment, be sure to tell your doctor about any other medications you take. It’s also important to talk with your doctor or pharmacist before you start taking any new medications with Tibsovo.

To read about health conditions that may increase your risk of side effects with Tibsovo, see the “Precautions for Tibsovo” section below.

If you have additional questions about your risk of side effects with Tibsovo, talk with your doctor.

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

Differentiation syndrome

Tibsovo has a boxed warning about the risk of a serious side effect called differentiation syndrome. A boxed warning is the most serious warning from the Food and Drug administration (FDA). It alerts doctors and patients about side effects that may be dangerous.

Differentiation syndrome is a serious condition that affects your blood cells. It can be life threatening if it isn’t treated. In clinical trials, differentiation syndrome was commonly reported in people with acute myeloid leukemia who took Tibsovo.

Symptoms of differentiation syndrome can include:

In the clinical trials, people who experienced differentiation syndrome had symptoms that began between 1 day and 3 months after starting Tibsovo treatment.

What you can do

If you have symptoms of differentiation syndrome while taking Tibsovo, see your doctor right away. However, if your symptoms feel life threatening, call 911 or your local emergency number.

If your doctor determines that you have differentiation syndrome, you may need to go to a hospital. You may be treated with a corticosteroid drug such as dexamethasone. You may also be given a medication called hydroxyurea (Droxia, Hydrea). In addition, your doctor may stop your Tibsovo treatment until you recover. You’ll likely need to stay in the hospital for at least 3 days and until the differentiation syndrome eases.

Low energy

In clinical trials, low energy was commonly reported with Tibsovo. Low energy is also called fatigue.

Low energy may be described as feeling weak, tired, or exhausted. It’s a common side effect of many cancer treatments. Low energy can also be a symptom of anemia, which is a possible side effect of Tibsovo. Anemia is a low level of a protein called hemoglobin.

What you can do

If you have low energy with Tibsovo, talk with your doctor. They may order a blood test to check your hemoglobin level. Your doctor can also give you advice on how to manage low energy.

Here are some tips for raising your energy level:

  • Try to improve your sleep. Most people sleep better in a cool, dark, and quiet room.
  • Split activities into smaller chunks and take regular breaks in between.
  • Ask for help and accept it when offered.
  • Rest when you can.
  • Get regular light exercise to help increase your strength. This can make activities less demanding, so you have more energy to spare.
  • Drink plenty of water.
  • Eat nutritious foods.

Guillain-Barré syndrome

Some people taking Tibsovo may develop a serious nerve disorder called Guillain-Barré syndrome. However, in clinical trials, this side effect was rare.

Guillain-Barré syndrome occurs when your immune system mistakenly attacks your nerves. Symptoms of this condition can include:

  • tingling, burning, or prickling feelings
  • weakness in your arms, legs, or upper body
  • numbness or pain in one or both sides of your body
  • changes in your eyesight, hearing, taste, or sense of touch
  • trouble breathing

What you can do

If you have symptoms of Guillain-Barré syndrome while taking Tibsovo, see your doctor right away. If your doctor determines that you have this side effect, they’ll likely have you stop taking the drug.

Symptoms of Guillain-Barré syndrome can usually be managed with medication. However, it can take months or years to recover. In some cases, the syndrome can lead to long-term paralysis or life threatening problems. If you have concerns about Guillain-Barré syndrome and Tibsovo, talk with your doctor.

Long QT syndrome

Tibsovo can sometimes cause long QT syndrome, which is a type of abnormal heart rhythm. In clinical trials, long QT syndrome was commonly reported with Tibsovo.

Long QT syndrome is diagnosed with an EKG, which is a test that measures the electrical activity in your heart.

Symptoms of long QT syndrome may include dizziness and fainting. Another possible symptom is feeling like your heart is racing, pounding, or skipping beats.

Long QT syndrome can increase your risk of arrhythmia (irregular heart rate or rhythm). Long QT syndrome may also lead to sudden cardiac arrest (a condition in which your heart stops beating).

You may have a higher risk than usual of long QT syndrome with Tibsovo if you:

What you can do

Before you start Tibsovo treatment, be sure to tell your doctor about any medications you take. And if you have a heart problem, ask your doctor whether Tibsovo is safe for you.

Your doctor may order an EKG to check your heart rhythm before and during your Tibsovo treatment. They may also order blood tests to check your electrolyte levels. Be sure to keep your appointments for any tests.

If you have symptoms of long QT syndrome while taking Tibsovo, see your doctor right away. However, if your symptoms feel life threatening, call 911 or your local emergency number.

If your doctor diagnoses long QT syndrome, they may prescribe medication. They may also reduce your Tibsovo dosage or have you stop taking the drug.

Diarrhea

In clinical trials, diarrhea was one of the most common side effects reported with Tibsovo.

Diarrhea due to Tibsovo is usually mild. However, in some cases, it can be severe. Having diarrhea can cause your body to lose fluids as well as electrolytes such as sodium and potassium. This can lead to dehydration and low electrolyte levels.

Low levels of electrolytes may increase your risk of long QT syndrome, which is a serious side effect of Tibsovo. (See “Long QT syndrome” above to read more about this.)

What you can do

If you have diarrhea with Tibsovo, it’s important to drink plenty of fluids to avoid becoming dehydrated. Oral rehydration solutions such as Pedialyte or sports drinks such as Gatorade can be useful. These beverages also help replace electrolytes that you can lose with diarrhea.

To help prevent diarrhea from worsening, try to avoid foods that are rich, spicy, greasy, sugary, or high in fiber. It may also help to avoid milk products, alcohol, and caffeine. Instead, stick to bland foods that your body can easily digest, such as rice, bananas, and dry toast.

If you have diarrhea that’s severe or lasts longer than a couple of days, talk with your doctor. They may recommend taking medication such as Imodium (loperamide) to help stop the diarrhea.

Allergic reaction

As with most drugs, Tibsovo can cause an allergic reaction in some people. 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 Tibsovo. If your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Before taking Tibsovo, there are certain precautions to consider. This includes a boxed warning from the Food and Drug Administration (FDA).

Boxed warning: Differentiation syndrome

Tibsovo has a boxed warning about the risk of differentiation syndrome. This is a serious warning from the 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 Tibsovo. This drug may not be the right treatment for you if you have certain medical conditions or other factors that affect your health. The conditions and factors to consider include:

Allergic reaction. If you’ve had an allergic reaction to Tibsovo or any of its ingredients, your doctor will likely not prescribe Tibsovo. Ask your doctor about other medications that may be better options for you.

Heart problems. Tibsovo can sometimes cause a type of abnormal heart rhythm called long QT syndrome.* You may have an increased risk of this side effect if you have certain heart problems, such as heart failure, a slow heart rate, or arrhythmia. If you have a heart problem, talk with your doctor about whether Tibsovo is right for you.

Low electrolyte levels. Tibsovo can sometimes cause a type of abnormal heart rhythm called long QT syndrome. You may have an increased risk of this side effect if you have low blood levels of electrolytes such as sodium or potassium. Your doctor will order blood tests to check your electrolyte levels before you take Tibsovo and from time to time during treatment. If you have low electrolyte levels, your doctor will likely prescribe medication to correct the problem.

Kidney or liver problems. Tibsovo has not been studied in people with severe kidney or liver problems. If you have severe kidney or liver problems, talk with your doctor about whether Tibsovo is safe for you.

* To learn more, see “Long QT syndrome” in the “Side effect specifics” section above.

Alcohol and Tibsovo

Alcohol does not interact with Tibsovo. However, drinking alcohol could worsen certain side effects that you may have with Tibsovo. These can include nausea, diarrhea, headache, and low energy.

If you drink alcohol, talk with your doctor about how much, if any, is safe to drink with Tibsovo.

Pregnancy and breastfeeding while taking Tibsovo

Tibsovo is not safe to take during pregnancy. If you’re pregnant or plan to become pregnant, ask your doctor about other medications that may be better options for you.

You should not breastfeed while taking Tibsovo and for at least 1 month after your last dose. If you’re breastfeeding or plan to breastfeed, talk with your doctor. They can advise you on healthy ways to feed your child while you take Tibsovo.

As with many cancer treatments, Tibsovo can commonly cause side effects. Most of the drug’s side effects are mild and easily managed, but some serious side effects are also possible. Be sure to talk with your doctor if you develop any serious side effects.

If you’d like to learn more about Tibsovo, 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:

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.