ITOVEBI contains inavolisib, a kinase inhibitor. The chemical name of inavolisib is (2S)-2-[[2-[(4S)-4-(difluoromethyl)-2-oxo-oxazolidin-3-yl]-5,6-dihydroimidazo[1,2-d][1,4]benzoxazepin-9-yl]amino]propanamide. Inavolisib is a white to off-white, greyish pink, greyish orange, or greyish yellow powder or powder with lumps. Inavolisib demonstrates pH-dependent aqueous solubility; the greatest solubility is at low pH, and solubility decreases with increasing pH. The molecular formula for inavolisib is C 18 H 19 F 2 N 5 O 4 and the molecular weight is 407.37 g/mol. The chemical structure of inavolisib is shown below: ITOVEBI film-coated tablets are supplied for oral administration with two strengths that contain 3 mg and 9 mg of inavolisib. The tablets also contain lactose, magnesium stearate, microcrystalline cellulose, and sodium starch glycolate. The film-coating contains the following inactive ingredients: polyvinyl alcohol (partially hydrolyzed), titanium dioxide, macrogol/polyethylene glycol, talc, iron oxide red, and iron oxide yellow (in the 9 mg tablet only). Chemical Structure

ITOVEBI, in combination with palbociclib and fulvestrant, is indicated for the treatment of adults with endocrine-resistant, PIK3CA -mutated, hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced or metastatic breast cancer, as detected by an FDA-approved test, following recurrence on or after completing adjuvant endocrine therapy . ITOVEBI is a kinase inhibitor indicated in combination with palbociclib and fulvestrant for the treatment of adults with endocrine-resistant, PIK3CA -mutated, hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced or metastatic breast cancer, as detected by an FDA-approved test, following recurrence on or after completing adjuvant endocrine therapy. ( 1 , 14.1 )

Tablets: 3 mg: red and round convex-shaped with an "INA 3" debossing on one side. 9 mg: pink and oval-shaped with an "INA 9" debossing on one side. Tablets: 3 mg and 9 mg

Select patients for the treatment of HR-positive, HER2-negative, locally advanced or metastatic breast cancer with ITOVEBI based on the presence of one or more PIK3CA mutations in plasma specimen. Recommended dosage: 9 mg orally once daily with or without food. See Full Prescribing Information for dosage modifications of ITOVEBI due to adverse reactions. Reduce the starting dose in patients with moderate renal impairment

Patient Selection Select patients for the treatment of HR-positive, HER2-negative, locally advanced or metastatic breast cancer with ITOVEBI based on the presence of one or more PIK3CA mutations in plasma specimens . Information on FDA-approved tests for the detection of PIK3CA mutations in breast cancer is available at: http://www.fda.gov/companiondiagnostics

Recommended Evaluation Before Initiating ITOVEBI Evaluate fasting plasma glucose (FPG)/blood glucose (FBG) and hemoglobin A 1C (HbA 1C ) and optimize blood glucose prior to starting ITOVEBI and at regular intervals during treatment

Recommended Dosage The recommended dosage of ITOVEBI is 9 mg taken orally once daily, with or without food, until disease progression or unacceptable toxicity. Advise patients to take ITOVEBI at approximately the same time each day. Swallow ITOVEBI tablet(s) whole. Do not chew, crush, or split prior to swallowing. If a patient misses a dose, instruct the patient to take the missed dose as soon as possible within 9 hours. After more than 9 hours, instruct the patient to skip the dose and take the next dose at the scheduled time. If a patient vomits a dose, instruct patients not to take an additional dose on that day and resume the usual dosing schedule the next day. Administer ITOVEBI in combination with palbociclib and fulvestrant. The recommended dosage of palbociclib is 125 mg taken orally once daily for 21 consecutive days followed by 7 days off treatment to comprise a cycle of 28 days. Refer to the Full Prescribing Information for palbociclib and fulvestrant for dosing information. For premenopausal and perimenopausal women, administer a luteinizing hormone-releasing hormone (LHRH) agonist in accordance with local clinical practice. For men, consider administering an LHRH agonist in accordance with local clinical practice

Dosage Modifications for Adverse Reactions The recommended dose reduction levels of ITOVEBI for adverse reactions are listed in Table 1 . Permanently discontinue ITOVEBI if patients are unable to tolerate the second dose reduction. Table 1: Dose Reduction for Adverse Reactions Dose Level Dose and Schedule Recommended starting dose 9 mg daily First dose reduction 6 mg daily Second dose reduction 3 mg daily The recommended dosage modifications of ITOVEBI for adverse reactions are summarized in Table 2 . Table 2: Recommended Dosage Modifications for Adverse Reactions Adverse Reaction Severity Dosage Modification Hyperglycemia Before initiating treatment with ITOVEBI, test FPG or FBG, and HbA 1C levels, and optimize plasma/blood glucose levels in all patients. After initiating treatment with ITOVEBI, monitor FPG or FBG levels based on the recommended schedule, and as clinically indicated . Fasting glucose levels (FPG or FBG) > ULN to 160 mg/dL (> ULN – 8.9 mmol/L) No adjustment of ITOVEBI required. Consider dietary modifications and ensure adequate hydration. Initiate or intensify oral anti-hyperglycemic medications for patients with risk factors for hyperglycemia. Fasting glucose levels > 160 to 250 mg/dL (> 8.9 – 13.9 mmol/L) Withhold ITOVEBI until FPG or FBG ≤ 160 mg/dL (≤ 8.9 mmol/L). Initiate or intensify anti-hyperglycemic medications. Resume ITOVEBI at the same dose level. If FPG or FBG persists > 200 – 250 mg/dL (> 11.1 – 13.9 mmol/L) for 7 days under appropriate anti-hyperglycemic treatment, consider consultation with a healthcare professional experienced in the treatment of hyperglycemia. Fasting glucose levels > 250 to 500 mg/dL (> 13.9 – 27.8 mmol/L) Withhold ITOVEBI. Initiate or intensify anti-hyperglycemic medications. Administer appropriate hydration if required. If FPG or FBG decreases to ≤ 160 mg/dL (≤ 8.9 mmol/L) within 7 days, resume ITOVEBI at the same dose level. If FPG or FBG decreases to ≤ 160 mg/dL (≤ 8.9 mmol/L) in ≥ 8 days, resume ITOVEBI at one lower dose level. If FPG or FBG > 250 to 500 mg/dL (> 13.9 – 27.8 mmol/L) recurs within 30 days, withhold ITOVEBI until FPG or FBG decreases to ≤ 160 mg/dL (≤ 8.9 mmol/L). Resume ITOVEBI at one lower dose level. Fasting glucose levels > 500 mg/dL (> 27.8 mmol/L) Withhold ITOVEBI. Initiate or intensify anti-hyperglycemic medications. Assess for volume depletion and ketosis and administer appropriate hydration. If FPG or FBG decreases to ≤ 160 mg/dL (≤ 8.9 mmol/L), resume ITOVEBI at one lower dose level. If FPG or FBG > 500 mg/dL (> 27.8 mmol/L) recurs within 30 days, permanently discontinue ITOVEBI. Stomatitis Grade 1 Based on CTCAE version 5.0. No adjustment of ITOVEBI required. Initiate or intensify appropriate medical therapy (e.g., corticosteroid-containing mouthwash) as clinically indicated. Grade 2 Withhold ITOVEBI until recovery to Grade ≤ 1. Initiate or intensify appropriate medical therapy. Resume ITOVEBI at the same dose level. For recurrent Grade 2 stomatitis, withhold ITOVEBI until recovery to Grade ≤ 1, then resume ITOVEBI at one lower dose level. Grade 3 Withhold ITOVEBI until recovery to Grade ≤ 1. Initiate or intensify appropriate medical therapy. Resume ITOVEBI at one lower dose level. Grade 4 Permanently discontinue ITOVEBI. Diarrhea Grade 1 No adjustment of ITOVEBI required. Initiate appropriate medical therapy and monitor as clinically indicated. Grade 2 Withhold ITOVEBI until recovery to Grade ≤ 1, then resume ITOVEBI at the same dose level. Initiate or intensify appropriate medical therapy and monitor as clinically indicated. For recurrent Grade 2 diarrhea, withhold ITOVEBI until recovery to Grade ≤ 1, then resume ITOVEBI at one lower dose level. Grade 3 Withhold ITOVEBI until recovery to Grade ≤ 1, then resume ITOVEBI at one lower dose level. Initiate or intensify appropriate medical therapy and monitor as clinically indicated. Grade 4 Permanently discontinue ITOVEBI. Hematologic Toxicities Grade 1, 2, or 3 No adjustment of ITOVEBI required. Monitor complete blood count and for signs or symptoms of hematologic toxicities as clinically indicated. Grade 4 Withhold ITOVEBI until recovery to Grade ≤ 2. Resume ITOVEBI at the same dose level or reduce to one lower dose level as clinically indicated. Other Adverse Reactions Grade 1 No adjustment of ITOVEBI required. Grade 2 Consider withholding ITOVEBI, if clinically indicated, until recovery to Grade ≤ 1. Resume ITOVEBI at the same dose level. Grade 3 (first event) Withhold ITOVEBI until recovery to Grade ≤ 1. Resume ITOVEBI at the same dose level or one lower dose level based on clinical evaluation. Grade 3 (recurrent) Withhold ITOVEBI until recovery to Grade ≤ 1. Resume ITOVEBI at one lower dose level. Grade 4 Permanently discontinue ITOVEBI

Dosage Modification for Moderate Renal Impairment The recommended starting dosage of ITOVEBI for patients with moderate renal impairment (eGFR 30 to < 60 mL/min based on CKD-EPI) is 6 mg orally once daily .

Hyperglycemia : ITOVEBI can cause severe or fatal hyperglycemia including ketoacidosis. Before initiating treatment with ITOVEBI, test fasting plasma glucose (FPG), HbA1c, and optimize blood glucose. Initiate or optimize anti-hyperglycemic medications as clinically indicated. Interrupt, reduce dose, or discontinue ITOVEBI if severe hyperglycemia occurs. Stomatitis : ITOVEBI can cause severe stomatitis. Consider treating with a corticosteroid-containing mouthwash if stomatitis occurs. Monitor patients for signs and symptoms of stomatitis. Withhold, reduce dose, or permanently discontinue ITOVEBI based on severity. Diarrhea : ITOVEBI can cause diarrhea, which may be severe, and result in dehydration and acute kidney injury. Advise patients to start anti-diarrheal treatment, increase oral fluids, and notify their healthcare provider if severe diarrhea occurs. Interrupt, reduce dose, or discontinue ITOVEBI if severe diarrhea occurs. Embryo-Fetal Toxicity : ITOVEBI can cause fetal harm. Advise patients of potential risk to a fetus and to use effective non-hormonal contraception. ( 5.4 , 8.1 , 8.3 ) Refer to the Full Prescribing Information of palbociclib and fulvestrant for pregnancy and contraception information

Hyperglycemia Severe or fatal hyperglycemia, including ketoacidosis, can occur in patients treated with ITOVEBI. Ketoacidosis with a fatal outcome has occurred in the postmarketing setting. Increased fasting glucose occurred in 85% of patients treated with ITOVEBI, including 22% of patients with Grade 2 (FPG > 160 to 250 mg/dL), 12% with Grade 3 (FPG > 250 to 500 mg/dL), and 0.6% with Grade 4 (FPG > 500 mg/dL) events. In INAVO120, 46% (74/162) of patients who received ITOVEBI were treated with oral anti-hyperglycemic medications and 7% (11/162) were treated with insulin to manage increased fasting glucose. In patients who experienced increased fasting glucose of > 160 mg/dL, 96% (52/54) had an improvement in fasting glucose of at least one grade level with a median time to improvement of 8 days (range: 2 to 43 days). Among patients with hyperglycemia, the median time to first onset was 7 days (range: 2 to 955 days). Hyperglycemia led to dose interruption in 28%, to dose reduction in 2.5%, and to discontinuation of ITOVEBI in 1.2% of patients. The safety of ITOVEBI in patients with Type 1 diabetes mellitus, or Type 2 diabetes mellitus requiring ongoing anti-hyperglycemic treatment have not been studied. Before initiating treatment with ITOVEBI, test fasting glucose levels (FPG or FBG), HbA 1C levels, and optimize fasting glucose. After initiating treatment with ITOVEBI, or in patients who experience hyperglycemia after initiating treatment with ITOVEBI, monitor or self-monitor fasting glucose levels once every 3 days for the first week (Day 1 to 7), then once every week for the next 3 weeks (Day 8 to 28), then once every 2 weeks for the next 8 weeks, then once every 4 weeks thereafter, and as clinically indicated. Monitor HbA 1C every 3 months and as clinically indicated. Manage hyperglycemia with anti-hyperglycemic medications as clinically indicated. During treatment with anti-hyperglycemic medication, continue monitoring fasting glucose levels. Patients with a history of well-controlled Type 2 diabetes mellitus may require intensified anti-hyperglycemic treatment and close monitoring of fasting glucose levels. Consider consultation with a healthcare professional experienced in the treatment of hyperglycemia, and initiation of fasting glucose monitoring at home for patients who have risk factors for hyperglycemia or who experience hyperglycemia. Advise patients of the signs and symptoms of hyperglycemia and counsel patients on lifestyle changes. Based on the severity of the hyperglycemia, ITOVEBI may require dose interruption, reduction, or discontinuation

Stomatitis Severe stomatitis can occur in patients treated with ITOVEBI. Stomatitis occurred in 51% of patients treated with ITOVEBI in combination with palbociclib and fulvestrant, including Grade 3 events in 6% of patients. The median time to first onset was 13 days (range: 1 to 610 days). Stomatitis led to dose interruption in 10%, to dose reduction in 3.7%, and to discontinuation of ITOVEBI in 0.6% of patients. In patients who received ITOVEBI in combination with palbociclib and fulvestrant, 38% used a mouthwash containing corticosteroid for management or prophylaxis of stomatitis. Monitor patients for signs and symptoms of stomatitis. Withhold, reduce dose, or permanently discontinue ITOVEBI based on severity

Diarrhea Severe diarrhea, including dehydration and acute kidney injury, can occur in patients treated with ITOVEBI. Diarrhea occurred in 48% of patients treated with ITOVEBI in combination with palbociclib and fulvestrant, including Grade 3 events in 3.7% of patients. The median time to first onset was 15 days (range: 2 to 602 days). Diarrhea led to dose interruptions in 7% of patients, and dose reductions in 1.2% of patients. Anti-diarrheal medicines were used in 28% (46/162) of patients who received ITOVEBI in combination with palbociclib and fulvestrant to manage symptoms. Monitor patients for signs and symptoms of diarrhea. Advise patients to increase oral fluids and start anti-diarrheal treatment at the first sign of diarrhea while taking ITOVEBI. Withhold, reduce dose, or permanently discontinue ITOVEBI based on severity

Embryo-Fetal Toxicity Based on findings in animals and its mechanism of action, ITOVEBI can cause fetal harm when administered to a pregnant woman . In an animal reproduction study, oral administration of inavolisib to pregnant rats during the period of organogenesis caused adverse developmental outcomes, including embryo-fetal mortality, structural abnormalities, and alterations to growth at maternal exposures approximately equivalent to the human exposure at the recommended dose of 9 mg/day based on area under the curve (AUC). Advise pregnant women and females of reproductive potential of the potential risk to a fetus. Advise females of reproductive potential to use effective non-hormonal contraception during treatment with ITOVEBI and for 1 week after the last dose. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with ITOVEBI and for 1 week after the last dose . ITOVEBI is used in combination with palbociclib and fulvestrant. Refer to the Full Prescribing Information of palbociclib and fulvestrant for pregnancy and contraception information.