Ontruzant

Dosage and Administration, Evaluation and Testing Before Initiating Ontruzant ( 2.1 ) 02/2025

1 INDICATIONS AND USAGE Ontruzant is a HER2/neu receptor antagonist indicated in adults for: The treatment of HER2-overexpressing breast cancer. ( 1.1 , 1.2 ) The treatment of HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma. ( 1.3 ) Select patients for therapy based on an FDA-approved companion diagnostic for a trastuzumab product ( 1 , 2.2 ). 1.1 Adjuvant Breast Cancer Ontruzant is indicated in adults for adjuvant treatment of HER2 overexpressing node positive or node negative (ER/PR negative or with one high risk feature [see Clinical Studies (14.1) ] ) breast cancer as part of a treatment regimen consisting of doxorubicin, cyclophosphamide, and either paclitaxel or docetaxel as part of a treatment regimen with docetaxel and carboplatin as a single agent following multi-modality anthracycline based therapy. Select patients for therapy based on an FDA-approved companion diagnostic for a trastuzumab product [see Dosage and Administration (2.2) ] . 1.2 Metastatic Breast Cancer Ontruzant is indicated in adults: In combination with paclitaxel for first-line treatment of HER2-overexpressing metastatic breast cancer As a single agent for treatment of HER2-overexpressing breast cancer in patients who have received one or more chemotherapy regimens for metastatic disease. Select patients for therapy based on an FDA-approved companion diagnostic for a trastuzumab product [see Dosage and Administration (2.2) ] . 1.3 Metastatic Gastric Cancer Ontruzant is indicated in adults, in combination with cisplatin and capecitabine or 5-fluorouracil, for the treatment of patients with HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma who have not received prior treatment for metastatic disease. Select patients for therapy based on an FDA-approved companion diagnostic for a trastuzumab product [see Dosage and Administration (2.2) ] .

2 DOSAGE AND ADMINISTRATION For intravenous (IV) infusion only. Do not administer as an IV push or bolus. Ontruzant has different dosage and administration instructions than subcutaneous trastuzumab products. ( 2.3 ) Do not substitute Ontruzant (trastuzumab-dttb) for or with ado-trastuzumab emtansine or fam-trastuzumab deruxtecan. ( 2.3 ) Perform HER2 testing using FDA-approved tests by laboratories with demonstrated proficiency. ( 1 , 2.2 ) Adjuvant Treatment of HER2-Overexpressing Breast Cancer ( 2.2 ) Administer at either: Initial dose of 4 mg/kg over 90 minute IV infusion, then 2 mg/kg over 30 minute IV infusion weekly for 12 weeks (with paclitaxel or docetaxel) or 18 weeks (with docetaxel and carboplatin). One week after the last weekly dose of Ontruzant, administer 6 mg/kg as an IV infusion over 30 to 90 minutes every three weeks to complete a total of 52 weeks of therapy, or Initial dose of 8 mg/kg over 90 minutes IV infusion, then 6 mg/kg over 30 to 90 minutes IV infusion every three weeks for 52 weeks. Metastatic HER2-Overexpressing Breast Cancer ( 2.3 ) Initial dose of 4 mg/kg as a 90 minute IV infusion followed by subsequent weekly doses of 2 mg/kg as 30 minute IV infusions. Metastatic HER2-Overexpressing Gastric Cancer ( 2.3 ) Initial dose of 8 mg/kg over 90 minutes IV infusion, followed by 6 mg/kg over 30 to 90 minutes IV infusion every 3 weeks. 2.1 Evaluation and Testing Before Initiating Ontruzant Assess left ventricular ejection fraction (LVEF) prior to initiation of Ontruzant and at regular intervals during treatment. [see Boxed Warning , Dosage and Administration (2.5) , Warnings and Precautions (5.1) ]. Verify the pregnancy status of females of reproductive potential prior to the initiation of Ontruzant [see Warnings and Precautions (5.3) , Use in Specific Populations (8.1 , 8.3) ] . 2.2 Patient Selection Select patients based on HER2 protein overexpression or HER2 gene amplification in tumor specimens [see Indications and Usage (1) and Clinical Studies (14) ] . Assessment of HER2 protein overexpression and HER2 gene amplification should be performed using FDA-approved tests specific for breast or gastric cancers by laboratories with demonstrated proficiency. Information on the FDA-approved tests for the detection of HER2 protein overexpression and HER2 gene amplification is available at: http://www.fda.gov/CompanionDiagnostics. Assessment of HER2 protein overexpression and HER2 gene amplification in metastatic gastric cancer should be performed using FDA-approved tests specifically for gastric cancers due to differences in gastric vs. breast histopathology, including incomplete membrane staining and more frequent heterogeneous expression of HER2 seen in gastric cancers. Improper assay performance, including use of suboptimally fixed tissue, failure to utilize specified reagents, deviation from specific assay instructions, and failure to include appropriate controls for assay validation, can lead to unreliable results. 2.3 Recommended Dosage Ontruzant is for intravenous infusion only. Do not administer as an intravenous push or bolus. Ontruzant has different dosage and administration instructions than subcutaneous trastuzumab products. Do not mix Ontruzant with other drugs. Do not substitute Ontruzant (trastuzumab-dttb) for or with ado-trastuzumab emtansine or fam-trastuzumab deruxtecan. Adjuvant Treatment of Breast Cancer: Administer according to one of the following doses and schedules for a total of 52 weeks of Ontruzant therapy: During and following paclitaxel, docetaxel, or docetaxel and carboplatin: Initial dose of 4 mg/kg as an intravenous infusion over 90 minutes then at 2 mg/kg as an intravenous infusion over 30 minutes weekly during chemotherapy for the first 12 weeks (paclitaxel or docetaxel) or 18 weeks (docetaxel and carboplatin). One week following the last weekly dose of Ontruzant, administer Ontruzant at 6 mg/kg as an intravenous infusion over 30 to 90 minutes every three weeks. As a single a …

3 DOSAGE FORMS AND STRENGTHS For injection: 150 mg of Ontruzant as a white to pale yellow, preservative-free lyophilized powder in a single-dose vial. For injection: 420 mg of Ontruzant as a white to pale yellow, preservative-free lyophilized powder in a multiple-dose vial. For Injection: 150 mg lyophilized powder in a single-dose vial for reconstitution. ( 3 ) For Injection: 420 mg lyophilized powder in a multiple-dose vial for reconstitution. ( 3 )

4 CONTRAINDICATIONS None. None. ( 4 )

6 ADVERSE REACTIONS The following adverse reactions are discussed in greater detail in other sections of the label: Cardiomyopathy [see Warnings and Precautions (5.1) ] Infusion Reactions [see Warnings and Precautions (5.2) ] Embryo-Fetal Toxicity [see Warnings and Precautions (5.3) ] Pulmonary Toxicity [see Warnings and Precautions (5.4) ] Exacerbation of Chemotherapy-induced Neutropenia [see Warnings and Precautions (5.5) ] Adjuvant Breast Cancer Most common adverse reactions (≥ 5%) are headache, diarrhea, nausea, and chills. ( 6.1 ) Metastatic Breast Cancer Most common adverse reactions (≥ 10%) are fever, chills, headache, infection, congestive heart failure, insomnia, cough, and rash. ( 6.1 ) Metastatic Gastric Cancer Most common adverse reactions (≥ 10%) are neutropenia, diarrhea, fatigue, anemia, stomatitis, weight loss, upper respiratory tract infections, fever, thrombocytopenia, mucosal inflammation, nasopharyngitis, and dysgeusia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Organon LLC, a subsidiary of Organon & Co., at 1-844-674-3200 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials 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. The most common adverse reactions in patients receiving trastuzumab products in the adjuvant and metastatic breast cancer setting are fever, nausea, vomiting, infusion reactions, diarrhea, infections, increased cough, headache, fatigue, dyspnea, rash, neutropenia, anemia, and myalgia. Adverse reactions requiring interruption or discontinuation of trastuzumab product treatment include CHF, significant decline in left ventricular cardiac function, severe infusion reactions, and pulmonary toxicity [see Dosage and Administration (2.5) ] . In the metastatic gastric cancer setting, the most common adverse reactions (≥ 10%) that were increased (≥ 5% difference) in the trastuzumab arm as compared to the chemotherapy alone arm were neutropenia, diarrhea, fatigue, anemia, stomatitis, weight loss, upper respiratory tract infections, fever, thrombocytopenia, mucosal inflammation, nasopharyngitis, and dysgeusia. The most common adverse reactions which resulted in discontinuation of treatment on the trastuzumab-containing arm in the absence of disease progression were infection, diarrhea, and febrile neutropenia. Adjuvant Breast Cancer The information below reflects exposure to one-year trastuzumab therapy across three randomized, open-label studies, NSABP B31, NCCTG N9831, and HERA, with (n = 3678) or without (n = 3363) trastuzumab in the adjuvant treatment of breast cancer. HERA Table 3 reflects exposure to trastuzumab in 1678 patients in HERA; the median treatment duration was 51 weeks and median number of infusions was 18 [see Clinical Studies (14.1) ] . Table 3 Adverse Reactions (≥1%) in HERA (All Grades) The incidence of Grade 3 or higher adverse reactions was <1% in both arms for each listed term. Adverse Reactions Trastuzumab (n = 1678) % Observation (n = 1708) % Nervous System Headache 10 3 Paresthesia 2 0.6 Musculoskeletal Arthralgia 8 6 Back pain 5 3 Myalgia 4 1 Bone pain 3 2 Muscle spasm 3 0.2 Infections Nasopharyngitis 8 3 Urinary tract infection 3 0.8 Gastrointestinal Diarrhea 7 1 Nausea 6 1 Vomiting 3.5 0.6 Constipation 2 1 Dyspepsia 2 0.5 Upper abdominal pain 2 1 General Pyrexia 6 0.4 Peripheral edema 5 2 Chills 5 0 Asthenia 4.5 2 Influenza-like illness 2 0.2 Respiratory Thoracic Mediastinal Cough 5 2 Influenza 4 0.5 Dyspnea 3 2 URI 3 1 Rhinitis 2 0.4 Pharyngolaryngeal pain 2 0.5 Sinusitis 2 0.3 Epistaxis 2 0.06 Cardiac Hypertension 4 2 Dizziness 4 2 Ejection fraction decreased 3.5 0.6 Palpitations 3 0.7 Cardiac arrhythmias Higher level grouping term. 3 1 Cardiac failure (congestive) 2 0.3 Skin & Subcutaneous Tissue Rash 4 0.6 Nail dis …

7 DRUG INTERACTIONS Anthracyclines Patients who receive anthracycline after stopping trastuzumab products may be at increased risk of cardiac dysfunction because of trastuzumab products' estimated long washout period [see Clinical Pharmacology (12.3) ] . If possible, avoid anthracycline-based therapy for up to 7 months after stopping trastuzumab products. If anthracyclines are used, closely monitor the patient's cardiac function.

8 USE IN SPECIFIC POPULATIONS Females and Males of Reproductive Potential: Verify the pregnancy status of females prior to initiation of Ontruzant ( 8.3 ). 8.1 Pregnancy Risk Summary Trastuzumab products can cause fetal harm when administered to a pregnant woman. In post-marketing reports and published literature, use of trastuzumab products during pregnancy resulted in cases of oligohydramnios and of oligohydramnios sequence, manifesting as pulmonary hypoplasia, skeletal abnormalities, and neonatal death (see Data ). Apprise the patient of the potential risks to a fetus. There are clinical considerations if a trastuzumab product is used in a pregnant woman or if a patient becomes pregnant within 7 months following the last dose of a trastuzumab product (see Clinical Considerations ). The background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Fetal/Neonatal Adverse Reactions Monitor women who received Ontruzant during pregnancy or within 7 months prior to conception for oligohydramnios. If oligohydramnios occurs, perform fetal/neonatal testing that is appropriate for gestational age and consistent with community standards of care. Data Human Data In post-marketing reports and published literature, use of trastuzumab products during pregnancy resulted in cases of oligohydramnios and of oligohydramnios sequence. Fetal manifestations included pulmonary hypoplasia, skeletal abnormalities, and neonatal death. These case reports described oligohydramnios in pregnant women who received trastuzumab either alone or in combination with chemotherapy. In most reported cases, amniotic fluid index increased after trastuzumab was stopped. In reported cases where trastuzumab therapy was resumed after amniotic index improved, oligohydramnios recurred. Animal Data In studies where trastuzumab was administered to pregnant Cynomolgus monkeys during the period of organogenesis at doses up to 25 mg/kg given twice weekly (up to 25 times the recommended weekly human dose of 2 mg/kg), trastuzumab crossed the placental barrier during the early (Gestation Days 20 to 50) and late (Gestation Days 120 to 150) phases of gestation. The resulting concentrations of trastuzumab in fetal serum and amniotic fluid were approximately 33% and 25%, respectively, of those present in the maternal serum but were not associated with adverse developmental effects. 8.2 Lactation Risk Summary There is no information regarding the presence of trastuzumab products in human milk, the effects on the breastfed infant, or the effects on milk production. Published data suggest human IgG is present in human milk but does not enter the neonatal and infant circulation in substantial amounts. Trastuzumab was present in the milk of lactating Cynomolgus monkeys but not associated with neonatal toxicity (see Data ). Consider the developmental and health benefits of breastfeeding along with the mother's clinical need for Ontruzant treatment and any potential adverse effects on the breastfed child from Ontruzant or from the underlying maternal condition. This consideration should also take into account the trastuzumab product wash out period of 7 months [see Clinical Pharmacology (12.3) ]. Data In lactating cynomolgus monkeys, trastuzumab was present in breast milk at about 0.3% of maternal serum concentrations after pre-(beginning Gestation Day 120) and post-partum (through Post-partum Day 28) doses of 25 mg/kg administered twice weekly (25 times the recommended weekly human dose of 2 mg/kg of trastuzumab products). Infant monkeys with detectable serum levels of trastuzumab did not exhibit any adverse effects on growth or development from birth to 1 month of age. 8.3 Females and Males of Reproductive Potential Pregnancy Testing Verify the pregnancy …

12.1 Mechanism of Action The HER2 (or c-erbB2) proto-oncogene encodes a transmembrane receptor protein of 185 kDa, which is structurally related to the epidermal growth factor receptor. Trastuzumab products have been shown, in both in vitro assays and in animals, to inhibit the proliferation of human tumor cells that overexpress HER2. Trastuzumab products are mediators of antibody-dependent cellular cytotoxicity (ADCC). In vitro , trastuzumab product-mediated ADCC has been shown to be preferentially exerted on HER2 overexpressing cancer cells compared with cancer cells that do not overexpress HER2.

11 DESCRIPTION Trastuzumab-dttb is a humanized IgG1 kappa monoclonal antibody that selectively binds with high affinity to the extracellular domain of the human epidermal growth factor receptor 2 protein, HER2. Trastuzumab-dttb is produced by recombinant DNA technology in a mammalian cell (Chinese Hamster Ovary) culture. Ontruzant (trastuzumab-dttb) for injection is a sterile, white to pale yellow, preservative-free lyophilized powder with a cake-like appearance, for intravenous administration. Each multiple-dose vial of Ontruzant delivers 420 mg trastuzumab-dttb, 381.4 mg α,α-trehalose dihydrate, 9.4 mg L-histidine HCl monohydrate, 6.1 mg L-histidine, and 1.7 mg polysorbate 20. Reconstitution with 20 mL of the appropriate diluent (BWFI or SWFI) yields a solution containing 21 mg/mL trastuzumab-dttb at a pH of approximately 6. If Ontruzant is reconstituted with SWFI without preservative, the reconstituted solution is considered single-dose. Each single-dose vial of Ontruzant delivers 150 mg trastuzumab-dttb, 136.2 mg α,α-trehalose dihydrate, 3.4 mg L-histidine HCl monohydrate, 2.2 mg L-histidine, and 0.6 mg polysorbate 20. Reconstitution with 7.4 mL of sterile water for injection (SWFI) yields a solution containing 21 mg/mL trastuzumab-dttb that delivers 7.15 mL (150 mg trastuzumab-dttb), at a pH of approximately 6.

16 HOW SUPPLIED/STORAGE AND HANDLING 420 mg Multiple-dose vial Ontruzant (trastuzumab-dttb) for injection 420 mg/vial is supplied in a multiple-dose vial as a white to pale yellow lyophilized sterile powder, under vacuum. Each carton contains one multiple-dose vial of Ontruzant and one vial (20 mL) of Bacteriostatic Water for Injection (BWFI), USP, containing 1.1% benzyl alcohol as a preservative. NDC 78206-148-01. 150 mg Single-dose vial Ontruzant (trastuzumab-dttb) for injection 150 mg/vial is supplied in a single-dose vial as a white to pale yellow lyophilized sterile powder, under vacuum. Each carton contains one single-dose vial of Ontruzant. NDC 78206-147-01. Store Ontruzant vials in the refrigerator at 2° to 8°C (36° to 46°F) until time of reconstitution.