Siltuximab

SYLVANT

Open Siltuximab in the interactive console ↗

Pronunciation: sil-TUX-i-mab (SIL-vant)

Siltuximab ballicule: receptor binding, kinetics and half-life diagram — Mechanism of action: Siltuximab ballicule

What it isIL-6 monoclonal antibody; idiopathic multicentric Castleman disease.

Why this oneIt is the only approved therapy for idiopathic multicentric Castleman disease.

What limits itIt suppresses CRP, so infection is masked. GI perforation; infusion reactions.

Siltuximab molecular structure (skeletal formula) — Molecular structure: Siltuximab

FDA-approved for

multicentric Castleman disease (2014)

FDA label

Read the full label on DailyMed ↗

FDA dosing	Population	Start	Target	Max
Multicentric Castleman disease (HIV-negative, HHV-8-negative)	Adults	11 mg/kg IV over 1 h q3wk	11 mg/kg q3wk	11 mg/kg q3wk

Renal No adjustment needed (CLcr ≥15 mL/min)

Hepatic No adjustment needed (mild-moderate; severe/Child-Pugh C not studied)

Every 3 weeks; delay (do not reduce) dose if ANC/platelet/hemoglobin criteria not met

Instructions

Intravenous infusion only, over 1 hour
Do not reduce dose — delay treatment if hematology criteria not met
Perform hematology tests before each dose for first 12 months, then every 3 cycles
Do not administer to patients with severe infection until it resolves
Permanently discontinue for severe infusion reaction, anaphylaxis, or cytokine release syndrome

Available strengths

inj 100, 400 mg

Cautions

Concurrent active severe infections — do not administer until resolved
No live vaccines
Infusion-related reactions and anaphylaxis
Gastrointestinal perforation

Adverse reactions

Rash
Pruritus
Upper respiratory tract infection
Increased weight
Hyperuricemia
Edema

Pregnancy May cause fetal harm; infants may be at increased risk of infection; animal placental transfer

Lactation Breastfeeding not recommended during and for 3 months after the last dose

Cost

Siltuximab (SYLVANT)

Strength		#/mo	generic $/unit	CostPlus
100 mg	inj	per unit		not offered
400 mg	inj	per unit		not offered

NADAC is a voluntary CMS survey of what retail community pharmacies pay for the drugs they stock. Siltuximab is administered under clinical supervision and dispensed outside retail pharmacies, so it rarely appears on surveyed invoices.

NO BOXED WARNINGS

Principal riskIt suppresses CRP, so infection is masked

Classes and tags

Clinical profile

Therapeutic safety burden2 / 4

Overdose danger2 / 4

Weight-gain liability2 / 4

Sedation liability0 / 4

QT / Torsades0 / 4

Direct muscarinic antagonism0 / 4

Embryofetal risk2 / 4

Defining liabilitySerious infection, infusion reactions and GI perforation

Open Siltuximab in the interactive console ↗

Memory aids: interaction avatars

no kinetic interactions

Open Siltuximab in the interactive console ↗