imlifidase: clinical use

Prescribing considerations

• Hospital-only treatment supervised by clinicians experienced in sensitised kidney transplantation and immunosuppression.
• Reserve for highly sensitised adults with a positive crossmatch against an available deceased donor who are unlikely to receive a transplant through the available allocation system.
• Confirm crossmatch conversion and ensure preparedness to diagnose and treat antibody-mediated rejection.
• Review infection status, chronic infection control, vaccination and antibody-based therapies.
• Evidence in older adults is limited; safety and efficacy are unestablished in children and in moderate or severe hepatic impairment.
• Subject to additional monitoring and conditional approval.

Contraindications and cautions

• Hypersensitivity to imlifidase or an excipient
• Ongoing serious bacterial, viral or fungal infection
• Thrombotic thrombocytopenic purpura

Monitoring

• Observe during and after infusion for allergic or infusion-related reactions.
• Confirm crossmatch conversion using a validated method; some assay configurations can produce misleading results after IgG cleavage.
• Monitor anti-HLA donor-specific antibodies and kidney function closely after transplantation.
• Investigate suspected antibody-mediated rejection promptly, with biopsy readiness where clinically indicated.
• Monitor for infection and ensure locally specified prophylaxis.
• Report suspected adverse reactions through the MHRA Yellow Card scheme.

Clinical pharmacology

Imlifidase cleaves the heavy chains of all human IgG subclasses, removing Fc-mediated complement and cellular effector functions. IgG subsequently returns. Routine total-IgG turbidimetry or nephelometry cannot reliably distinguish intact IgG from generated fragments.

Formulation and product differences

• The UK product is a refrigerated powder for concentrate requiring reconstitution and dilution before intravenous infusion.
• The solution contains polysorbate 80 and is essentially sodium-free.
• Use a low-protein-binding inline filter and discard solutions containing particles or discolouration.

Solution for infusion

Route: Intravenous

Strengths: 11 mg