Tibsovo (Ivosidenib)

Tibsovo is an anti-cancer prescription medication also known by the generic name ivosidenib. It is indicated for the treatment of acute myeloid leukemia (AML) and cholangiocarcinoma, which is bile duct cancer. 

Acute myeloid leukemia is the most common type of leukemia (blood and bone marrow cancer) in adults. Tibsovo can be used for the treatment of newly diagnosed AML in adults 75 years or older and for the treatment of relapsed/refractory AML.

Before starting this medication, make sure to tell your healthcare provider if you have any of the following conditions:

• Any known medication or food allergy 
• A history of seizures
• An HIV diagnosis 
• Pregnant or breastfeeding or planning to become pregnant
• A history of heart problems
• Kidney disease
• Cirrhosis or liver disease
• Nerve problems
• An electrolyte imbalance (low levels of sodium, potassium, or magnesium in the blood).

What Is Tibsovo Used For?

Components of blood such as red blood cells, white blood cells, and platelets are produced in the bone marrow. Acute myeloid leukemia (AML) occurs when the bone marrow produces large numbers of abnormal immature white blood cells called myeloblasts. These abnormal cells do not function properly and crowd out healthy blood cells, which can lead to infections, anemia, and bleeding problems.

Some cases of acute myeloid leukemia are linked to genetic mutations such as IDH1 mutations. This mutation prevents myeloblasts from maturing into normal functioning blood cells. Approximately 10% of people with AML have an IDH1 mutation. Tibsovo is a targeted therapy that works by blocking the mutant IDH1 enzyme, which helps restore normal cell development.

How Long Does It Take for Tibsovo To Work?

Therapy management and treatment duration depend on patient factors and adherence. 

Side Effects

Some patients might experience one or more of the following side effects while on treatment with Tibsovo: 

• Stomach upset 
• Fatigue 
• Muscle or joint pain
• Mouth irritation or mouth sores
• Loss of appetite
• Weight loss
• Headache
• Acne
• Constipation
• Diarrhea
• Nausea and vomiting 

Tibsovo Strength

Tibsovo is available as 250 mg oral tablets.

Dosing

• The recommended dose is 500 mg (two 250-mg tablets) taken by mouth once daily for a minimum of 6 months if tolerated.
• It is best to take this medication at the same time each day
• Tablets should be swallowed whole
• Do not split, crush, or chew the tablets
• If a dose is missed, it should be taken as soon as it is remembered unless it is within 12 hours of the next scheduled dose. Do not take two doses on the same day.

How Long Can You Take Tibsovo?

Tibsovo is continued for a minimum of 6 months if therapy is tolerated and there is no disease progression. 

When To Discontinue Tibsovo?

• Tibsovo may cause differentiation syndrome, a serious and potentially life-threatening condition. Symptoms may include fever, difficulty breathing (dyspnea), low oxygen levels (hypoxia), rapid weight gain, swelling (edema), and low blood pressure. If these symptoms occur, patients should seek immediate medical attention. Treatment may include corticosteroids and temporary interruption of therapy as directed by a healthcare provider.
• If a patient develops signs of an allergic reaction, such as hives, swelling of the face or throat, chest pain, dizziness, or abnormal heartbeat, seek immediate medical care or call 911.
• Therapy is also discontinued if the patient experiences toxicity or disease progression. 

Tibsovo Interactions – Food And Drugs To Avoid

Tibsovo may be taken with or without food, but it should not be taken with a high-fat meal because this can increase medication levels in the body, which can raise the risk for side effects.

Tibsovo can increase the risk of QT interval prolongation, which can lead to a serious heart rhythm disorder.  Let your prescriber know if you have any heart issues or are taking an antiarrhythmic medication, such as amiodarone or flecainide.

Tibsovo may also interact with certain antibiotics and other medications that affect liver enzymes responsible for drug metabolism. Inform your prescriber and pharmacist about any antibiotic medications you are taking.

Tibsovo can reduce the efficacy of hormonal contraceptives. Patients should discuss their concerns with their provider at the initial visit. 

There are many other drug interactions with Tibsovo. Please make sure to have your provider and pharmacist check for these interactions before starting Tibsovo.  

Pregnancy or Planning Pregnancy

Tibsovo may affect fertility in both males and females. Please inform your provider if you are pregnant or planning on becoming pregnant. Breastfeeding is NOT recommended while on this medication.

Is Tibsovo Chemotherapy?

Tibsovo is not a chemotherapy drug. It is a targeted therapy anti-cancer prescription medication.

The difference between targeted therapy and chemotherapy is that targeted therapy works on specific molecular targets associated with cancer while chemotherapy works on all rapidly dividing cancerous and normal cells.

Tibsovo is an oral targeted therapy drug that inhibits the IDH1 enzyme.

Is Tibsovo FDA-Approved?

Ivosidenib is the first IDH1 inhibitor approved by the U.S. Food and Drug Administration (FDA). It was initially approved in 2018 for the treatment of acute myeloid leukemia (AML) with an IDH1 mutation, with additional approvals and expanded indications granted in later years, including treatment for advanced or metastatic cholangiocarcinoma.

Conclusion

Ivosidenib, sold under the brand name Tibsovo, is a targeted anti-cancer prescription medicine that inhibits the mutant IDH1 enzyme. Inhibition of the enzyme promotes the production of healthy myeloid cells (blood cells). It is used to treat advanced bile duct cancer and acute myeloid leukemia (AML). 

Like many cancer treatments, Tibsovo can cause side effects, such as stomach upset, fatigue, muscle or joint pain, mouth irritation or mouth sores, loss of appetite, headache, acne, constipation, or diarrhea.

Some side effects may improve as the body adjusts to treatment.

If side effects persist or you encounter severe adverse effects like heart problems, irregular heart palpitations, symptoms of QT interval prolongation, fainting, or uncontrollable breathing problems, please seek medical attention immediately and inform your provider.

Do not stop this medication without your doctor’s recommendation. Inform your pharmacist and doctor about your medical conditions and drug history before starting Tibsovo.