Warnings for Margenza
Included as part of the "PRECAUTIONS" Section
Precautions for Margenza
Left Ventricular Dysfunction
Left ventricular cardiac dysfunction can occur with MARGENZA. In SOPHIA, left ventricular dysfunction occurred in 1.9% of patients treated with MARGENZA. MARGENZA has not been studied in patients with a pretreatment LVEF value of < 50%, a prior history of myocardial infarction or unstable angina within 6 months, or congestive heart failure NYHA class II-IV.
Withhold MARGENZA for ≥ 16% absolute decrease in LVEF from pretreatment values or LVEF value below institutional limits of normal (or 50% if no limits are available) and ≥ 10% absolute decrease in LVEF from pretreatment values. Permanently discontinue MARGENZA if LVEF decline persists for greater than 8 weeks, or if dosing is interrupted on greater than 3 occasions due to LVEF decline [see DOSAGE AND ADMINISTRATION].
Cardiac Monitoring
Conduct thorough cardiac assessment, including history, physical examination, and determination of LVEF by echocardiogram or MUGA scan. The following schedule is recommended:
- Baseline LVEF measurement within 4 weeks prior to initiation of MARGENZA
- LVEF measurements (MUGA/echocardiogram) every 3 months during and upon completion of MARGENZA
- Repeat LVEF measurement at 4-week intervals if MARGENZA is withheld for significant left ventricular cardiac dysfunction [see DOSAGE AND ADMINISTRATION].
Embryo-Fetal Toxicity
Based on findings in animals and mechanism of action, MARGENZA can cause fetal harm when administered to a pregnant woman. There are no available data on the use of MARGENZA in pregnant women to inform the drug-associated risk. In postmarketing reports, use of a HER2-directed antibody during pregnancy resulted in cases of oligohydramnios and oligohydramnios sequence manifesting as pulmonary hypoplasia, skeletal abnormalities and neonatal death. In an animal reproduction study, intravenous administration of margetuximab-cmkb to pregnant cynomolgus monkeys once every 3 weeks starting at gestational day (GD) 20 until delivery resulted in oligohydramnios and delayed infant kidney development. Animal exposures were ≥ 3 times the human exposures at the recommended dose, based on Cmax .
Verify pregnancy status of females of reproductive potential prior to initiation of MARGENZA. Advise pregnant women and females of reproductive potential that exposure to MARGENZA during pregnancy or within 4 months prior to conception can result in fetal harm. Advise females of reproductive potential to use effective contraception during treatment and for 4 months following the last dose of MARGENZA [see Use In Specific Populations].
Infusion-Related Reactions
MARGENZA can cause infusion-related reactions (IRRs) [see ADVERSE REACTIONS]. Symptoms may include fever, chills, arthralgia, cough, dizziness, fatigue, nausea, vomiting, headache, diaphoresis, tachycardia, hypotension, pruritus, rash, urticaria, and dyspnea.
In SOPHIA, IRRs were reported by 13% of patients on MARGENZA plus chemotherapy. Most of the IRRs occur during Cycle 1. Grade 3 IRRs were reported in 1.5% of MARGENZA-treated patients. All IRRs resolved within 24 hours, irrespective of severity. In SOPHIA, IRRs leading to interruption of treatment occurred in 9% of patients treated with MARGENZA and chemotherapy. One patient (0.4%) on MARGENZA discontinued treatment due to IRR.
An infusion substudy in 88 patients in SOPHIA evaluated MARGENZA administered over 120 minutes for the initial dose, then 30 minutes from Cycle 2 forward. IRRs were ≤ Grade 2 and most occurred during the first (120 minutes) administration of MARGENZA. From Cycle 2 onward, one patient (1.1%) had an IRR (Grade 1).
Monitor patients for IRRs during MARGENZA administration and as clinically indicated after completion of infusion. Have medications and emergency equipment to treat IRRs available for immediate use. Monitor patients carefully until resolution of signs and symptoms.
In patients who experience mild or moderate IRRs, consider premedications, including antihistamines, corticosteroids, and antipyretics. Decrease the rate of infusion for mild or moderate IRRs. Interrupt MARGENZA infusion in patients experiencing dyspnea or clinically significant hypotension and intervene with medical therapy which may include epinephrine, corticosteroids, diphenhydramine, bronchodilators and oxygen. Patients should be evaluated and carefully monitored until complete resolution of signs and symptoms. Permanently discontinue MARGENZA in all patients with severe or lifethreatening IRRs.
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, And Impairment Of Fertility
Studies have not been performed to evaluate carcinogenic or mutagenic potential of margetuximab-cmkb.
Animal fertility studies have not been conducted with margetuximab-cmkb. In repeatdose toxicity studies of up to 13-week duration, margetuximab-cmkb had no effect on male and female reproductive organs in sexually mature cynomolgus monkeys.
Use In Specific Populations
Pregnancy
Risk Summary
Based on findings in animals and mechanism of action, MARGENZA can cause fetal harm when administered to a pregnant woman. There are no available data on use of MARGENZA in pregnant women to inform the drug-associated risk. In postmarketing reports, use of a HER2-directed antibody during pregnancy resulted in cases of oligohydramnios and oligohydramnios sequence manifesting as pulmonary hypoplasia, skeletal abnormalities, and neonatal death. In an animal reproduction study, intravenous administration of margetuximab-cmkb to pregnant cynomolgus monkeys once every 3 weeks, starting at gestational day (GD) 20 until delivery, resulted in oligohydramnios and delayed infant kidney development. Animal exposures were ≥ 3 times the human exposures at the recommended dose, based on Cmax (see CLINICAL PHARMACOLOGY). Advise patients of potential risks to a fetus. There are clinical considerations if MARGENZA is used during pregnancy or within 4 months prior to conception (see Clinical Considerations).
Estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, background risks of major birth defects and miscarriage in clinically recognized pregnancies are 2 - 4% and 15 - 20%, respectively. The denominator used to calculate the rate varied from 229 to 253 based on the number of patients with a baseline value and at least one post-treatment value.
Clinical Considerations
Fetal/Neonatal Adverse Reactions
Monitor women who received MARGENZA during pregnancy or within 4 months prior to conception for oligohydramnios. If oligohydramnios occurs, perform fetal testing that is appropriate for gestational age and consistent with community standards of care.
Data
Animal Data
In an enhanced pre- and post-natal development study, pregnant cynomolgus monkeys received intravenous doses of 50 or 100 mg/kg margetuximab-cmkb once every 3 weeks starting on GD 20 and until delivery. Animal exposures at doses of 50 and 100 mg/kg were 3 and 6 times, respectively, the human exposures at the recommended dose, based on Cmax . Treatment with 50 and 100 mg/kg margetuximab-cmkb resulted in oligohydramnios beginning on GD 75.
An infant mortality occurred on post-natal day 63 following maternal exposure to 100 mg/kg margetuximab-cmkb. Clinical findings included tubular degeneration/necrosis and tubular dilatation in the kidney. Maternal doses of 50 and 100 mg/kg resulted in decreased infant kidney weights and histologic immature nephrons. Measurable serum concentrations of margetuximab-cmkb were observed in infant animals, which is consistent with margetuximab-cmkb crossing the placenta.
Lactation
Risk Summary
There is no information regarding presence of MARGENZA in human milk, effects on the breastfed child, or effects on milk production. Published data suggest human IgG is present in human milk but does not enter neonatal or infant circulation in substantial amounts. Consider developmental and health benefits of breastfeeding along with the mother's clinical need for MARGENZA treatment and any potential adverse effects on the breastfed child from MARGENZA or from the underlying maternal condition. This consideration should also take into account the MARGENZA washout period of 4 months [see CLINICAL PHARMACOLOGY].
Females And Males Of Reproductive Potential
MARGENZA can cause fetal harm when administered to a pregnant woman.
Pregnancy Testing
Verify pregnancy status of females of reproductive potential prior to initiation of MARGENZA.
Contraception
Females
Advise females of reproductive potential to use effective contraception during treatment and for 4 months following the last dose of MARGENZA [see Pregnancy and CLINICAL PHARMACOLOGY].
Pediatric Use
Safety and effectiveness of MARGENZA have not been established in pediatric patients.
Geriatric Use
Of the 266 patients treated with MARGENZA 20% were 65 years of age or older and 4% were 75 years or older. No overall differences in efficacy were observed between patients ≥ 65 years of age compared to younger patients. There was a higher incidence of Grade ≥ 3 adverse reactions observed in patients age 65 years or older (56%) compared to younger patients (47%), as well as adverse reactions associated with potential cardiotoxicity (35% vs 18%).