WARNINGS
Included as part of the "PRECAUTIONS" Section
PRECAUTIONS
Concurrent Active Severe Infections
Do not administer SYLVANT to patients with severe infections until the infection resolves. SYLVANT may mask signs and symptoms of acute inflammation including suppression of fever and of acute Phase reactants such as C-reactive protein (CRP). Monitor patients receiving SYLVANT closely for infections. Institute prompt anti-infective therapy and do not administer further SYLVANT until the infection resolves.
Vaccinations
Do not administer live vaccines to patients or infants born to patients receiving SYLVANT because IL-6 inhibition may interfere with the normal immune response to new antigens [see Use In Specific Populations].
Infusion Related Reactions And Hypersensitivity
SYLVANT may cause infusion related reactions and anaphylaxis. Approximately 945 patients have been treated with SYLVANT in clinical trials. Of these, one patient experienced an anaphylactic reaction. Data from 254 patients treated with SYLVANT monotherapy forms the basis of the safety evaluation of infusion related reactions. Infusion related reactions were reported in 5.1% of these patients. Two (0.8%) were Grade 3 or higher, and 1 (0.4%) was serious; none were fatal. Symptoms of infusion reactions consisted of back pain, chest pain or discomfort, nausea and vomiting, flushing, erythema, and palpitations.
In long-term treatment of MCD patients with siltuximab at the recommended dosage of 11 mg/kg every 3 weeks, infusion related reactions or hypersensitivity reactions occurred at a frequency of 6.3% (1.3% for severe reactions).
Stop the infusion of SYLVANT if the patient develops signs of anaphylaxis. Discontinue further therapy with SYLVANT.
Stop the infusion if the patient develops a mild to moderate infusion reaction. If the reaction resolves, the SYLVANT infusion may be restarted at a lower infusion rate. Consider medication with antihistamines, acetaminophen, and corticosteroids. Discontinue SYLVANT if the patient does not tolerate the infusion following these interventions [see ADVERSE REACTIONS].
Administer SYLVANT in a setting that provides resuscitation equipment, medication, and personnel trained to provide resuscitation.
Gastrointestinal Perforation
Gastrointestinal (GI) perforation has been reported in clinical trials although not in MCD trials. Use with caution in patients who may be at increased risk for GI perforation. Promptly evaluate patients presenting with symptoms that may be associated or suggestive of GI perforation.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION).
Instruct the patient of the risks of SYLVANT treatment.
Infections
Inform patients that SYLVANT may lower their resistance to infections. Instruct the patient of the importance of contacting their doctor immediately when symptoms suggesting infection appear in order to assure rapid evaluation and appropriate treatment.
Vaccination
Inform the patient that they should discuss the recommended vaccinations prior to treatment with SYLVANT. Advise females with infants exposed to SYLVANT in utero to inform the pediatrician of the exposure [see Use In Specific Populations].
Allergic Reactions
Advise patients to seek immediate medical attention if they experience any symptoms of serious allergic reactions during the infusion. Signs include: difficulty breathing, chest tightness, wheezing, severe dizziness or light-headedness, swelling of the lips or skin rash.
Pregnancy
Advise patients of childbearing potential to avoid pregnancy and to use contraception during treatment and for 3 months after the last dose of SYLVANT.
Lactation
Advise females not to breastfeed during treatment with SYLVANT and for 3 months after the final dose [see Use In Specific Populations].
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
No carcinogenicity or genotoxicity studies have been conducted with siltuximab.
Two fertility studies were conducted. In one study, drug-treated male mice were mated with untreated females and in the second study drug-treated female mice were mated with untreated males. A murine analog of siltuximab was administered subcutaneously at doses up to 100 mg/kg/week for a total of 7 doses in both studies. There was no effect on male or female fertility parameters. In addition, siltuximab did not produce any toxicity in the reproductive organs in cynomolgus monkeys in the 6-month repeat-dose toxicology study at doses up to 46 mg/kg (approximately 7 times) the systemic exposure in patients at the recommended dose.
Use In Specific Populations
Pregnancy
Risk-Summary
In an animal reproduction study, intravenous administration of a human antibody to IL-6 to pregnant monkeys from the onset of organogenesis through delivery caused functional impairment in pregnant animals and in the offspring. Siltuximab and the human antibody to IL-6 crossed the placenta in monkeys (see Data). The limited available information on SYLVANT use during pregnancy is not sufficient to inform a drug-associated risk of major birth defects or miscarriage. Infants born to pregnant women treated with SYLVANT may be at increased risk of infection (see Clinical Considerations). Advise pregnant women of the potential risk to a fetus.
The estimated background risk for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects is 2% to 4% and of miscarriage is 15% to 20% of clinically recognized pregnancies.
Clinical Considerations
Fetal/Neonatal adverse reactions
Monoclonal antibodies are transported across the placenta as pregnancy progresses, with the largest amount transferred during the third trimester. Infants born to pregnant women treated with SYLVANT may be at increased risk of infection. Consider the risks and benefits of administering live or live-attenuated vaccines to infants exposed to SYLVANT in utero [see WARNINGS AND PRECAUTIONS].
Data
Animal Data
In an embryo-fetal development study in cynomolgus monkeys, pregnant animals received intravenous doses of siltuximab of 9.2 or 46 mg/kg/week during gestation days (GD) 20 to 118, which includes the period of organogenesis. Fetuses were evaluated on GD 140, approximately 25 days prior to the natural birth. Exposures at the low and high dose after the 25th administration were approximately 3 and 7 times, respectively, the human exposure based on AUC in patients with MCD at the recommended dose of 11 mg/kg every three weeks. No maternal or fetal structural abnormalities were observed. However, siltuximab crossed the placenta at both doses and when measured on GD 140, fetal serum concentrations of siltuximab were similar to maternal concentrations. In a combined embryofetal and pre- and post-natal development study in cynomolgus monkeys, pregnant animals received intravenous doses of 10 or 50 mg/kg/week of a human antibody to IL-6 from GD 20 to natural delivery (GD 167). The offspring were evaluated up to 7 months after birth for developmental effects. No maternal or infant structural abnormalities were observed; however, globulin levels were decreased in pregnant animals (GD 34 through lactation day 30) and in the offspring (lactation days 30-120) at both doses.
Lactation
Risk Summary
There are no data on the presence of siltuximab in human milk, the effects on the breastfed child, or the effects on milk production. However, low levels of the human antibody to IL-6 was present in the milk of lactating cynomolgus monkeys. When a drug is present in animal milk, it is likely that the drug will be present in human milk. Because of the potential for serious adverse reactions in the breastfed child including gastrointestinal perforations, advise patients that breastfeeding is not recommended during treatment with SYLVANT, and for 3 months after the last dose.
Females And Males Of Reproductive Potential
Contraception
Females
SYLVANT may cause embryo-fetal harm when administered to pregnant women [see Pregnancy]. Advise female patients of reproductive potential to use effective contraception during treatment with SYLVANT and for 3 months after the last dose.
Pediatric Use
The safety and efficacy of SYLVANT have not been established in pediatric patients.
Geriatric Use
Of the patients treated with SYLVANT monotherapy in clinical studies 127 (35%) were 65 years and older. No overall differences in safety profile were observed between these patients and younger patients, and other reported clinical experience has not identified differences in the safety profile between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. Clinical studies did not include sufficient numbers of patients aged 65 years and older to determine the effect of age on efficacy in MCD population.
Patients With Renal Impairment
Based on a population pharmacokinetic analysis using data from clinical trials in patients, no significant difference in siltuximab clearance was observed in patients with pre-existing renal impairment (creatinine clearance (CLCr) ≥ 15 mL/min) compared to patients with baseline normal renal function (CLCr ≥ 90 mL/min). No initial dosage adjustment is necessary for patients with CLCr ≥ 15 mL/min. The potential effect of end stage renal disease on siltuximab pharmacokinetics cannot be determined [see CLINICAL PHARMACOLOGY].
Patients With Hepatic Impairment
Based on a population pharmacokinetic analysis using data from clinical trials in patients, no significant difference in siltuximab clearance was observed in patients with pre-existing mild to moderate hepatic impairment (Child-Pugh Class A and B, respectively) compared to patients with baseline normal hepatic function. No initial dosage adjustment is necessary for patients with mild to moderate hepatic impairment. Patients with baseline severe hepatic impairment (Child-Pugh Class C) were not included in clinical trials [see CLINICAL PHARMACOLOGY].