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Possible side effects with Itovebi and tips that may help

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Serious side effects
Common side effects
Tips that may help

Serious and common side effects

Like all medicines, Itovebi (inavolisib) can cause side effects. Be sure to tell your healthcare provider if you experience any changes in your body or health, as they may be signs of a side effect.

Itovebi may cause serious side effects, including:

Hyperglycemia icon

High blood sugar levels (hyperglycemia)
Higher than normal amount of sugar in the blood

  • Hyperglycemia is common with Itovebi and may be severe or fatal
  • Untreated severe hyperglycemia can lead to a condition called diabetic ketoacidosis that can happen in people treated with Itovebi
  • Diabetic ketoacidosis is a serious condition that requires treatment in a hospital and that can lead to death
  • Your healthcare provider will monitor your blood sugar levels before you start and during treatment with Itovebi
  • Tell your healthcare provider right away if you develop symptoms of high blood sugar, including excessive thirst, urinating more often, blurred vision, confusion, difficulty breathing, or increased appetite with weight loss
Mouth sores icon

Mouth sores (stomatitis)
Inflammation or irritation of the lining of the mouth

  • Mouth sores are common with Itovebi and may be severe. Tell your healthcare provider right away if you develop painful redness, swelling, or sores in your mouth
Diarrhea icon

Diarrhea
Frequent and watery bowel movements

  • Diarrhea is common with Itovebi and may be severe. Tell your healthcare provider right away if you develop diarrhea, stomach-area (abdominal) pain, or see mucus or blood in your stool during treatment with Itovebi

The most common side effects and abnormal blood test results of Itovebi when used in combination with palbociclib and fulvestrant include: decreased white blood cell counts, red blood cell counts, and platelet counts, decreased blood levels of calcium, potassium, sodium, and magnesium, increased creatinine blood levels, tiredness, increased blood levels of the liver enzyme alanine transaminase (ALT), nausea, rash, loss of appetite, COVID-19 infection, and headache.

To manage side effects, your healthcare provider may:

For the duration of the clinical trial, the majority of people taking Itovebi were able to stay on treatment. 6%, or 10 out of 162 people, completely stopped Itovebi treatment because of side effects. 14% (23 out of 162) took a lower dose and 69% (112 out of 162) delayed at least one dose of Itovebi.

Tips that may help

The tips mentioned below may not work for everyone. Be sure to talk to your care team before trying any of these tips or if you experience any side effects that bother or concern you.

  • Stay well-hydrated during treatment with Itovebi
  • If your healthcare provider asks you to self-monitor, talk to them about how and when to test and report your blood sugar levels
  • Your blood sugar levels may be monitored more often if you have a history of Type 2 diabetes
  • If you experience hyperglycemia, your healthcare provider may lower or delay your dose, prescribe medication, or suggest lifestyle modifications (such as dietary changes) to help with the symptoms

Learn more about hyperglycemia

  • Check your mouth daily and report any pain, redness, swelling, or ulcers to your healthcare team as soon as you notice them
  • Practice good mouth care, such as using an extra-soft toothbrush to gently brush your teeth; ask your healthcare team if you should floss
  • To lower the chances of mouth sores, your healthcare provider may recommend a medicated daily mouthwash
  • Be sure to discuss dietary options with your healthcare team if you develop stomatitis
  • Your healthcare provider may tell you to drink more fluids or take medicines to treat your diarrhea
  • Food and drinks you may want to try:
    • Water; drinks containing electrolytes (eg, sugar-free sports drinks); caffeine-free, sugar-free teas; and clear, fat-free broths
    • Gelatin, plain yogurt, and eggs
    • Toast, saltine crackers, and rice (however, if you have hyperglycemia, you may need to limit carbohydrates)
    • Skinless meats that can be broiled or baked (for example: turkey, chicken, and fish)
  • Foods and drinks you may want to avoid:
    • Juices or foods that have a laxative effect, such as prunes or prune juice
    • Drinks that contain alcohol or caffeine
    • Milk and other dairy products (except for yogurt)
    • Spicy, greasy, fried, and high-fiber foods
  • A rash is an area of the skin that has changes in texture or color and may look inflamed or irritated. The skin may be red, warm, scaly, bumpy, dry, itchy, swollen, painful, cracked, or blistered
  • Try to take quick showers or sponge baths instead of long, hot showers. Clean skin gently with warm water and mild, moisturizing soap; rinse and pat dry. Apply a fragrance- and alcohol-free moisturizer while skin is still damp
  • Wear soft, loose-fitting clothing
  • Avoid being in the sun as much as possible. If you need to be outside during the day, wear a hat and long-sleeved clothing and apply broad-spectrum sunscreen of at least SPF 30
  • Get skin care advice from your healthcare team if you develop a rash

Learn more about hyperglycemia, including tips that may help

These are not all of the side effects you may experience with Itovebi-based treatment.

Your care team will help you identify and manage your side effects, so please be sure to inform them of any symptoms and concerns.

NEXT: Hyperglycemia
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Important Safety Information & Use

What is Itovebi?

Itovebi® (inavolisib) is a prescription medicine used in combination with the medicines palbociclib and fulvestrant to treat adults who have hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer that has an abnormal phosphatidylinositol-3-kinase catalytic subunit alpha (PIK3CA) gene, and has spread to nearby tissue or lymph nodes (locally advanced), or to other parts of the body (metastatic), and has come back after hormone (endocrine) therapy.

Your healthcare provider will test your cancer for abnormal PIK3CA genes to make sure that Itovebi is right for you.

It is not known if Itovebi is safe and effective in children.

What are the possible side effects of Itovebi?

Itovebi may cause serious side effects, including:

  • High blood sugar levels (hyperglycemia). High blood sugar is common with Itovebi and may be severe or fatal. Untreated severe hyperglycemia can lead to a condition called diabetic ketoacidosis that can happen in people treated with Itovebi. Diabetic ketoacidosis is a serious condition that requires treatment in a hospital and that can lead to death. Your healthcare provider will monitor your blood sugar levels before you start and during treatment with Itovebi. Your blood sugar levels may be monitored more often if you have a history of Type 2 diabetes. Your healthcare provider may also ask you to self-monitor and report your blood sugar levels at home. This will be required more frequently in the first 4 weeks of treatment. If you are not sure how to test your blood sugar levels, talk to your healthcare provider. You should stay well-hydrated during treatment with Itovebi. Tell your healthcare provider right away if you develop symptoms of high blood sugar, including:

    • difficulty breathing
    • nausea and vomiting (lasting more than 2 hours)
    • stomach pain
    • excessive thirst
    • dry mouth
    • more frequent urination than usual or a higher amount of urine than normal
    • blurred vision
    • unusually increased appetite
    • weight loss
    • fruity-smelling breath
    • flushed face and dry skin
    • feeling unusually sleepy or tired
    • confusion
  • Mouth sores (stomatitis). Mouth sores are common with Itovebi and may be severe. Tell your healthcare provider if you develop any of the following in your mouth:
    • pain
    • redness
    • swelling
    • ulcers
  • Diarrhea. Diarrhea is common with Itovebi and may be severe. Severe diarrhea can lead to the loss of too much body water (dehydration) and kidney injury. Tell your healthcare provider right away if you develop diarrhea, stomach-area (abdominal) pain, or see mucus or blood in your stool during treatment with Itovebi. Your healthcare provider may tell you to drink more fluids or take medicines to treat your diarrhea.

Your healthcare provider may tell you to decrease your dose, temporarily stop your treatment, or completely stop your treatment with Itovebi if you develop certain serious side effects.

The most common side effects and abnormal blood test results of Itovebi when used in combination with palbociclib and fulvestrant include:

  • decreased white blood cell counts, red blood cell counts, and platelet counts
  • decreased blood levels of calcium, potassium, sodium, and magnesium
  • increased creatinine blood levels
  • tiredness
  • increased blood levels of the liver enzyme alanine transaminase (ALT)
  • nausea
  • rash
  • loss of appetite
  • COVID-19 infection
  • headache

Itovebi may affect fertility in males and in females who are able to become pregnant. Talk to your healthcare provider if this is a concern for you.

These are not all of the possible side effects of Itovebi. Call your healthcare provider for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. You may also report side effects to Genentech at (877) 436-3683.

Before you take Itovebi, tell your healthcare provider about all of your medical conditions, including if you:

  • have a history of diabetes or high blood sugar
  • have kidney problems
  • are pregnant or plan to become pregnant. Itovebi can harm your unborn baby.
    Females who are able to become pregnant:
    • Your healthcare provider will check to see if you are pregnant before you start treatment with Itovebi.
    • You should use effective non-hormonal birth control (contraception) during treatment with Itovebi and for 1 week after your last dose. Talk to your healthcare provider about what birth control method is right for you during this time.
    • Tell your healthcare provider right away if you become pregnant or think you may be pregnant during treatment with Itovebi.
    Males with female partners who are able to become pregnant:
    • You should use effective birth control (contraception) during treatment with Itovebi and for 1 week after your last dose.
  • are breastfeeding or plan to breastfeed. It is not known if Itovebi passes into your breastmilk. Do not breastfeed during treatment with Itovebi and for 1 week after your last dose. Talk to your healthcare provider about the best way to feed your baby during treatment with Itovebi.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

Please see the full Prescribing Information, including Patient Information, for additional Important Safety Information.

  • PI3K

    A type of protein that transmits signals in cells and is involved in cell growth

  • Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA)

    A gene that helps make the PI3K protein. Mutations in the PIK3CA gene may cause PI3K to become overactive, which may make cancer cells grow

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