Inavolisib

1 INDICATIONS AND USAGE 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 [see Clinical Studies (14.1) ] . 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 )

2 DOSAGE AND ADMINISTRATION 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. ( 2.1 ) Recommended dosage: 9 mg orally once daily with or without food. ( 2.3 ) See Full Prescribing Information for dosage modifications of ITOVEBI due to adverse reactions. ( 2.4 ) Reduce the starting dose in patients with moderate renal impairment. ( 2.5 ) 2.1 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 [see Clinical Studies (14.1) ] . Information on FDA-approved tests for the detection of PIK3CA mutations in breast cancer is available at: http://www.fda.gov/companiondiagnostics. 2.2 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 [see Warnings and Precautions (5.1) ]. 2.3 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. 2.4 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 [see Warnings and Precautions (5.1) ]. [see Warnings and Precautions (5.1) ] 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 [see Warnings and Precautions (5.2) ] 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 [see Warnings and Precautions (5.3) ] 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 [see Adverse Reactions (6.1) ] 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 [see Adverse Reactions (6.1) ] 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. 2.5 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 [see Use in Specific Populations (8.6) and Clinical Pharmacology (12.3) ] .

6 ADVERSE REACTIONS The following adverse reactions are discussed in greater detail in other sections of the label: Hyperglycemia [see Warnings and Precautions (5.1) ] Stomatitis [see Warnings and Precautions (5.2) ] Diarrhea [see Warnings and Precautions (5.3) ] The most common (≥ 20%) adverse reactions, including laboratory abnormalities, were decreased neutrophils, decreased hemoglobin, increased fasting glucose, decreased platelets, decreased lymphocytes, stomatitis, diarrhea, decreased calcium, fatigue, decreased potassium, increased creatinine, increased ALT, nausea, decreased sodium, decreased magnesium, rash, decreased appetite, COVID-19 infection, and headache. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Genentech at 1-888-835-2555 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trial Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Locally Advanced or Metastatic Breast Cancer INAVO120 The safety of ITOVEBI was evaluated in a randomized, double-blind, placebo-controlled study (INAVO120) in 324 patients with PIK3CA -mutated, HR-positive, HER2-negative, locally advanced or metastatic breast cancer [see Clinical Studies (14.1) ] . Patients received either ITOVEBI 9 mg (n=162) or placebo (n=162) with palbociclib and fulvestrant. The median duration of treatment with ITOVEBI was 9 months (range: 0 to 39 months) in the ITOVEBI with palbociclib and fulvestrant arm. Serious adverse reactions occurred in 24% of patients who received ITOVEBI with palbociclib and fulvestrant. Serious adverse reactions in ≥ 1% of patients included anemia (1.9%), diarrhea (1.2%), and urinary tract infection (1.2%). Fatal adverse reactions occurred in 3.7% of patients who received ITOVEBI with palbociclib and fulvestrant, including (0.6% each) acute coronary syndrome, cerebral hemorrhage, cerebrovascular accident, COVID-19 infection, and gastrointestinal hemorrhage. Permanent discontinuation of ITOVEBI due to an adverse reaction occurred in 6% of patients. Adverse reactions which resulted in permanent discontinuation of ITOVEBI included hyperglycemia (1.2%), and (0.6% each) stomatitis, gastric ulcer, intestinal perforation, anal abscess, increased ALT, decreased weight, bone pain, musculoskeletal pain, transitional cell carcinoma, and acute kidney injury. Dosage interruptions of ITOVEBI due to an adverse reaction occurred in 69% of patients. Adverse reactions which required dosage interruption in ≥ 2% of patients included hyperglycemia (28%), neutropenia (23%), COVID-19 infection (16%), stomatitis (10%), diarrhea (7%), thrombocytopenia (4.9%), anemia (4.3%), upper respiratory tract infection (4.3%), decreased white blood cell count (3.7%), pyrexia (3.1%), nausea (2.5%), and fatigue (2.5%). Dose reductions of ITOVEBI due to adverse reactions occurred in 14% of patients. Adverse reactions which required dose reduction of ITOVEBI in ≥ 2% of patients were stomatitis (3.7%) and hyperglycemia (2.5%). The most common (≥ 20%) adverse reactions, including laboratory abnormalities, were decreased neutrophils, decreased hemoglobin, increased fasting glucose, decreased platelets, decreased lymphocytes, stomatitis, diarrhea, decreased calcium, fatigue, decreased potassium, increased creatinine, increased ALT, nausea, decreased sodium, decreased magnesium, rash, decreased appetite, COVID-19 infection, and headache. Adverse reactions and laboratory abnormalities in INAVO120 are summarized in Table 3 and Table 4 , respectively. Patient-reported symptoms are summarized in Table 5 . Table 3: Adverse Reactions (≥ 10% with ≥ 5% [All Grades] or ≥ 2% [Grade 3-4] Higher Incidence in the ITOVEBI Arm) in INAVO120 Adverse Reaction ITOVEBI + Palbociclib + Fulvestrant N=162 Placebo + Palbociclib + Fulvestrant N=162 All Grades (%) Grade 3-4 (%) All Grades (%) Grade 3-4 (%) Gastrointestinal Disorders Stomatitis Includes aphthous ulcer, glossitis, glossodynia, lip ulceration, mouth ulceration, mucosal inflammation, and stomatitis. 51 6 No Grade 4 adverse reactions were observed. 27 0 Diarrhea 48 3.7 16 0 Nausea 28 0.6 17 0 Vomiting 15 0.6 5 1.2 General Disorders and Administration Site Conditions Fatigue 38 1.9 25 1.2 Skin and Subcutaneous Tissue Disorders Rash Includes other related terms. 26 0 19 0 Alopecia 19 0 6 0 Dry skin Includes dry skin, skin fissures, xerosis, and xeroderma. 13 0 4.3 0 Metabolism and Nutrition Disorders Decreased appetite 24 0 9 0 Infections and Infestations COVID-19 infection 23 1.9 11 0.6 Urinary tract infection 15 1.2 9 0 Nervous System Disorders Headache 22 0 14 0 Investigations Decreased weight 17 3.7 0.6 0 Clinically relevant adverse reactions occurring in < 10% of patients who received ITOVEBI in combination with palbociclib and fulvestrant included abdominal pain, dry eye, dysgeusia, and dyspepsia. Table 4: Select Laboratory Abnormalities (≥ 10% with a ≥ 2% [All Grades or Grade 3-4] Higher Incidence in the ITOVEBI Arm) in INAVO120 Laboratory Abnormality ITOVEBI + Palbociclib + Fulvestrant The denominator used to calculate the rate varied from 122 to 160 based on the number of patients with a baseline value and at least one post-treatment value. Placebo + Palbociclib + Fulvestrant The denominator used to calculate the rate varied from 131 to 161 based on the number of patients with a baseline value and at least one post-treatment value. All Grades (%) Grade 3-4 (%) All Grades (%) Grade 3-4 (%) ALT = alanine aminotransferase Hematology Neutrophils (total, absolute) decreased 95 82 97 79 Hemoglobin decreased 88 8 No Grade 4 laboratory abnormalities were observed. 85 2.5 Platelets decreased 84 16 71 3.7 Lymphocytes (absolute) decreased 72 9 68 14 Chemistry Glucose (fasting) increased Grading according to CTCAE version 4.03. 85 12 43 0 Calcium decreased 42 3.1 32 3.7 Potassium decreased 38 6 21 0.6 Creatinine increased 38 1.9 30 1.2 ALT increased 34 3.1 29 1.2 Sodium decreased 28 2.5 19 2.5 Magnesium decreased 27 0.6 21 0 Lipase (fasting) increased 16 1.4 7 0 In INAVO120, patient-reported symptomatic toxicities (i.e., diarrhea, nausea, vomiting, fatigue, mouth sores, decreased appetite, and rash) were assessed via the Patient-Reported Outcomes – Common Terminology Criteria for Adverse Events (PRO-CTCAE) at baseline, every two weeks through Cycle 3 Day 15, and then Day 1 of every other 28-day cycle until treatment discontinuation. Completion rates in both arms were > 90% at baseline and > 80% at subsequent time points where > 50% of randomized patients were on treatment. Table 5: Patient-Reported Symptoms Assessed by PRO-CTCAE in INAVO120 ITOVEBI+P+F = ITOVEBI with palbociclib and fulvestrant arm; Placebo+P+F = placebo with palbociclib and fulvestrant arm. Symptom (Attribute) The symptom attribute scoring is defined by amount/frequency/severity with a score of 0 = 'not at all'/'never'/'none'; 1 = 'a little bit'/'rarely'/'mild'; 2 = 'somewhat'/'occasionally'/'moderate'; 3 = 'quite a bit'/'frequently'/'severe'; 4 = 'very much'/'almost constantly'/'very severe'. Any Symptom Before Treatment (%) The percentage of patients whose symptom score before treatment was 1-4. Any Worsening on Treatment (%) The percentage of patients whose symptom score increased during treatment, with respect to their score before treatment. Worsening to Score 3 or 4 (%) The percentage of patients whose symptom score increased to 3 or 4 during treatment, with respect to their score before treatment. ITOVEBI + P + F (N=148) The number of patients who provided a score before treatment and at least one on-treatment score. Placebo + P + F (N=152) ITOVEBI + P + F (N=148) Placebo + P + F (N=152) ITOVEBI + P + F (N=148) Placebo + P + F (N=152) Diarrhea (frequency), % 23 15 78 49 32 8 Nausea (frequency), % 21 21 59 50 20 11 Vomiting (frequency), % 9 6 35 26 6 3.3 Fatigue (severity), % 72 69 72 58 32 22 Mouth sores (severity), % 11 14 74 52 30 9 Decreased appetite (severity), % 38 28 78 55 26 12 Symptom (Attribute) Baseline Presence Post-baseline Presence ITOVEBI + P + F (N=148) Placebo + P + F (N=152) ITOVEBI + P + F (N=148) Placebo + P + F (N=152) Rash (yes), % 5 5 50 38 Patient-reported overall side-effect impact was assessed using the Modified Bother Item (MBI). Patients provided a response to "I am bothered by side effects of treatment," and at baseline the proportion of patients with MBI responses of "not at all" were 70% in the ITOVEBI with palbociclib and fulvestrant arm and 76% in the placebo with palbociclib and fulvestrant arm. At Cycle 2 Day 15, the proportion of patients with MBI responses of "not at all" were 25% in the ITOVEBI with palbociclib and fulvestrant arm and 53% in the placebo with palbociclib and fulvestrant arm. Through 31 cycles of treatment, patients in the ITOVEBI with palbociclib and fulvestrant arm reported more side effect bother compared to the placebo with palbociclib and fulvestrant arm. 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of ITOVEBI. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Metabolism and Nutrition Disorders : Ketoacidosis

12.3 Pharmacokinetics Inavolisib pharmacokinetics are presented as geometric mean (geometric coefficient of variation [geo CV]%) following administration of the approved recommended dosage unless otherwise specified. The inavolisib steady-state AUC is 1,010 h*ng/mL (25%) and C max is 69 ng/mL (27%). Steady-state concentrations are predicted to be attained by day 5. Inavolisib accumulation is approximately 2-fold. Inavolisib steady-state AUC is proportional with dose from 6 to 12 mg (0.7 to 1.3 times the approved recommended dosage). Absorption Inavolisib absolute oral bioavailability is 76%. Inavolisib steady-state median (min, max) time to maximum plasma concentration (T max ) is 3 hours (0.5, 4 hours). Effect of Food No clinically significant differences in inavolisib pharmacokinetics were observed following administration of inavolisib with a high-fat meal (approximately 1,000 calories, 50% fat). Distribution Inavolisib apparent (oral) volume of distribution is 155 L (26%). Inavolisib plasma protein binding is 37% and is not concentration-dependent in vitro. Inavolisib blood-to-plasma ratio is 0.8. Elimination Inavolisib elimination half-life is 15 hours (24%) with a total clearance of 8.8 L/hr (29%). Metabolism Inavolisib is primarily metabolized by hydrolysis. In vitro, inavolisib was minimally metabolized by CYP3A. Excretion Following oral administration of a single radiolabeled dose, 49% of the administered dose was recovered in urine (40% unchanged) and 48% in feces (11% unchanged). Specific Populations No clinically significant differences in the pharmacokinetics of inavolisib were observed based on age (27 to 85 years), sex, race (Asian or White), body weight (39 to 159 kg), or mild hepatic impairment (total bilirubin > ULN to ≤ 1.5 × ULN or AST > ULN and total bilirubin ≤ ULN). The effect of moderate to severe hepatic impairment on inavolisib pharmacokinetics is unknown. Patients with Renal Impairment Inavolisib AUC was 73% higher in patients with moderate renal impairment compared to patients with normal renal function (eGFR ≥ 90 mL/min). No clinically significant differences in the pharmacokinetics of inavolisib were observed in patients with mild renal impairment compared to patients with normal renal function. The effect of severe renal impairment (eGFR < 30 mL/min) on the pharmacokinetics of inavolisib is unknown. Drug Interaction Studies Clinical Studies and Model-Informed Approaches Proton Pump Inhibitors: No clinically significant difference in steady-state inavolisib pharmacokinetics were observed based upon concomitant use of a proton pump inhibitor (lansoprazole, omeprazole, esomeprazole, pantoprazole, or rabeprazole). In Vitro Studies CYP450 Enzymes: Inavolisib induces CYP3A and CYP2B6. Inavolisib is a time-dependent inhibitor of CYP3A. Inavolisib does not inhibit CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, or CYP2D6. Transporter Systems: Inavolisib is a substrate of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), but is not a substrate of OATP1B1, OATP1B3, OCT1, OCT2, MATE1, MATE2K, OAT1, OAT2. Inavolisib does not inhibit P-gp, BCRP, OATP1B1, OATP1B3, OCT1, OCT2, OAT1, OAT3, MATE1, or MATE2K.