Inavolisib Dosage

Medically reviewed by Drugs.com. Last updated on Jan 28, 2025.

Usual Adult Dose for Breast Cancer

9 mg orally once a day, in combination with palbociclib and fulvestrant
Duration of therapy: Until disease progression or unacceptable toxicity

Comments:

• Ensure patients meet criteria for treatment based on PIK3CA cancer mutations.
• For pre- or perimenopausal women, administer a luteinizing hormone-releasing hormone (LHRH) agonist.
• Consider administering a LHRH agonist in men.
• Refer to the manufacturer product information for palbociclib and fulvestrant for complete dosing and administration recommendations.

Use: In combination with palbociclib and fulvestrant, for the treatment of endocrine-resistant, PIK3CA-mutated, hormone receptor-positive, human epidermal growth factor receptor 2-negative, locally advanced or metastatic breast cancer following recurrence on or after completing adjuvant endocrine therapy

Renal Dose Adjustments

Mild renal dysfunction (estimated GFR 60 to less than 90 mL/min): No adjustment recommended.
Moderate renal dysfunction (estimated GFR 30 to less than 60 mL/min): Recommended initial dose is 6 mg orally once a day.
Severe renal dysfunction (estimated GFR less than 30 mL/min): Data not available; population not studied.

Liver Dose Adjustments

Liver dysfunction: Data not available

Comments:

• There were no clinically significant pharmacokinetic differences in patients with mild liver dysfunction as compared to normal function.
• This drug was not studied in patients with moderate or severe liver dysfunction.

Dose Adjustments

General Dose Reduction Recommendations:

• First dose reduction: 6 mg orally once a day
• Second dose reduction: 3 mg orally once a day
• Permanently discontinue therapy if patient unable to tolerate second dose reduction.

Dosage Modifications for Adverse Reactions:
HYPERGLYCEMIA:
Fasting plasma or blood glucose levels greater than the upper limit of normal to 160 mg/dL (8.9 mmol/L):

• No adjustment recommended.
• Consider dietary modifications and ensure adequate hydration.
• Initiate or intensify oral antihyperglycemic medications in patients with risk factors for hyperglycemia.

Fasting plasma or blood glucose levels greater than 160 to 250 mg/dL (8.9 to 13.9 mmol/L):

• Withhold therapy until fasting glucose is 160 mg/dL (8.9 mmol/L) or less; then, resume at same dose level.
• Initiate or intensify antihyperglycemic medications.
• If fasting glucose levels persist above 200 to 250 mg/dL (11.1 to 13.9 mmol/L) for 7 days while taking appropriate anti-hyperglycemic treatment, consider consultation with a specialist.

Fasting plasma or blood glucose levels greater than 250 to 500 mg/dL (13.9 to 27.8 mmol/L):

• Withhold treatment, and initiate/intensify use of antihyperglycemic agents; administer hydration if required.
• If fasting glucose levels decrease to 160 mg/dL (8.9 mmol/L) or less within 7 days, resume therapy at the same dose level.
• If fasting glucose levels decrease to 160 mg/dL (8.9 mmol/L) or less in 8 days or greater, resume therapy at 1 lower dose level.
• If fasting glucose levels above 250 to 500 mg/dL (13.9 to 27.8 mmol/L) reoccur within 30 days, withhold therapy until fasting glucose levels decrease to 160 mg/dL (8.9 mmol/L) or less; then, resume therapy at 1 lower dose level.

Fasting plasma or blood glucose levels greater than 500 mg/dL (27.8 mmol/L):

• Withhold treatment, and initiate or intensify antihyperglycemic medications.
• Assess for volume depletion and ketosis, and administer hydration as appropriate.
• If fasting glucose levels decrease to 160 mg/dL (8.9 mmol/L) or less, resume therapy at 1 lower dose level.
• If fasting glucose levels above 250 to 500 mg/dL (13.9 to 27.8 mmol/L) reoccur within 30 days, permanently discontinue treatment.

STOMATITIS:

• Grade 1: No adjustment required. Initiate or intensify appropriate medical therapy (e.g., corticosteroid-containing mouthwash) as indicated.
• Grade 2: Withhold therapy until recovery to grade 1 or less, then resume at same dose level. Initiate or intensify appropriate medical management. For recurrent grade 2 stomatitis, withhold therapy until recovery to grade 1 or less, then resume at 1 lower dose level.
• Grade 3: Withhold therapy until recovery to grade 1 or less, then resume at 1 lower dose level. Initiate or intensify appropriate medical management.
• Grade 4: Permanently discontinue therapy.

DIARRHEA:

• Grade 1: No adjustment required. Initiate appropriate medical management and monitor as indicated.
• Grade 2: Withhold therapy until recovery to grade 1 or less, then resume at same dose level. Initiate or intensify appropriate medical management and monitor as indicated. For recurrent grade 2 diarrhea, withhold therapy until recovery to grade 1 or less, then resume at 1 lower dose level.
• Grade 3: Withhold therapy until recovery to grade 1 or less, then resume at 1 lower dose level. Initiate or intensify appropriate medical management and monitor as indicated.
• Grade 4: Permanently discontinue therapy.

HEMATOLOGIC TOXICITIES:

• Grade 1, 2, or 3: No adjustment required. Monitor complete blood count and for signs/symptoms of hematologic toxicities.
• Grade 4: Withhold therapy until recover to grade 2 or less. Resume therapy at the same dose level or reduce to 1 lower dose level, as clinically indicated.

OTHER ADVERSE REACTIONS:

• Grade 1: No adjustment required.
• Grade 2: Consider withholding therapy (if clinically indicated) until recovery to grade 1 or less. Resume at the same dose level.
• Grade 3: Withhold therapy until recovery to grade 1 or less. May resume at same dose level or 1 lower dose level based on clinical evaluation.
• Grade 4: Permanently discontinue therapy.

Precautions

CONTRAINDICATIONS: None

Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:

• Before starting therapy: Select patients for the treatment based on the presence of 1 or more PIK3CA mutations in plasma specimens using an FDA-approved test.
• Prior to initiation: Evaluate fasting plasma/blood glucose and hemoglobin A1c (HbA1c); optimize blood glucose levels as indicated.
• Administer this drug in combination with palbociclib and fulvestrant. The recommended dosage of palbociclib is 125 mg orally once a day for 21 days followed by 7 days off to comprise a cycle of 28 days.
• It is recommended to administer a LHRH in pre- or perimenopausal women in accordance with accepted practice; consider administration of a LHRH in men as well.
• Swallow tablets whole; do not crush, chew, or split.
• Doses should be taken at approximately the same time each day, with or without food.
• If a dose is missed, administer as soon as possible within 9 hours; if greater than 9 hours, dose should be skipped and taken at the next scheduled time.
• If vomiting of dose occurs, no additional doses should be taken that day; resume at next scheduled dosing time.

Storage requirements:

• Store at 20C to 25C (68F to 77F); excursions permitted between 15C and 30C (59F and 86F).

General:

• Information on FDA-approved tests for the detection of PIK3CA mutations in breast cancer is available at: http://www.fda.gov/companiondiagnostics.
• Consult the manufacturer product information for palbociclib, fulvestrant, or any LHRH used in combination with this drug.
• Report suspected adverse reactions to Genentech at 1-888-835-2555 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Monitoring:

• Endocrine: Fasting glucose levels, HbA1c (at baseline and at recommended intervals during therapy)
• Gastrointestinal: For signs/symptoms of stomatitis and diarrhea (during therapy)

Patient advice:

• Read the US FDA-approved patient labeling (Patient Information).
• Contact your health care provider immediately for signs and symptoms of hyperglycemia.
• Notify your health care provider if symptoms of stomatitis occur.
• Start antidiarrheal treatment, increase oral fluids, and notify your health care provider if diarrhea occurs.
• Patients of childbearing potential:
• Inform your health care provider of a known/suspected pregnancy; this drug may cause fetal harm.
• Females of reproductive potential or males with partners of reproductive potential should use non-hormonal contraceptives during therapy and for 1 week after the last dose.
• Breastfeeding is not recommended during treatment and for 1 week after the last dose.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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