inclisiran

Brand: Leqvio

Prototype Drug
Drug Class: small interfering RNA (siRNA) — PCSK9 inhibitor
Drug Family: antilipemic
Subclass: RNA interference lipid-lowering agent
Organ Systems: cardiovascular

Mechanism of Action

Double-stranded siRNA conjugated to N-acetylgalactosamine (GalNAc) for hepatocyte-targeted delivery; silences PCSK9 mRNA via RNA interference, reducing intracellular PCSK9 synthesis and thereby upregulating LDL receptors on hepatocyte surfaces to enhance LDL-C clearance.

PCSK9 mRNA (hepatic)

Indications

  • heterozygous familial hypercholesterolemia
  • atherosclerotic cardiovascular disease with elevated LDL-C inadequately controlled by maximally tolerated statin therapy

Contraindications

  • hypersensitivity to inclisiran or excipients

Adverse Effects

Common

  • injection site reactions (erythema, pain, swelling)
  • nasopharyngitis
  • urinary tract infection

Serious

  • serious hypersensitivity reactions (rare)

Pharmacokinetics (ADME)

Absorption subcutaneous administration; Cmax within 4 hours of injection
Distribution primarily distributed to the liver via GalNAc targeting; Vd approximately 500 L
Metabolism metabolized by nucleases to shorter oligonucleotides; not a CYP450 substrate
Excretion renal (minor — metabolite fragments); not dialyzable
Half-life approximately 9 hours (plasma); intracellular RISC complex confers durable effect lasting approximately 6 months
Onset LDL-C reduction begins within weeks; maximal effect at approximately 3 months
Peak 4 hours (plasma Cmax)
Duration approximately 6 months per dose
Protein Binding approximately 87%
Vd approximately 500 L

Drug Interactions

Drug / Agent Mechanism Severity
no clinically significant CYP450-mediated interactions identified not a CYP substrate or inhibitor; interaction potential low minor

Nursing Considerations

  1. Administer as a subcutaneous injection (284 mg in 1.5 mL) in the abdomen, upper arm, or thigh; rotate injection sites and avoid areas of skin inflammation or active skin conditions.
  2. The dosing schedule is distinctive — initial dose, repeat at 3 months, then every 6 months; confirm the patient understands this schedule to prevent missed doses or unintended re-dosing.
  3. Monitor LDL-C at 3 months after initiation and periodically thereafter to confirm therapeutic response; expect approximately 50% LDL-C reduction.
  4. Inclisiran is not self-administered — it must be given by a healthcare professional in a clinical setting; document administration dates meticulously in the medical record.

Clinical Pearls

  • Inclisiran achieves durable LDL-C lowering with only two doses per year after the initial loading doses, addressing adherence challenges associated with daily or monthly dosing regimens.
  • Unlike PCSK9 monoclonal antibodies (evolocumab, alirocumab) which inhibit circulating PCSK9 protein, inclisiran prevents PCSK9 synthesis at the mRNA level — effectively reducing PCSK9 for months per injection.

Safety Profile

Pregnancy avoid
Lactation insufficient-data
Renal Adjustment Required
Hepatic Adjustment Not required
TDM Not required
Guideline Update pending