ENSPRYNG

What it is

Enspryng contains satralizumab 120 mg in 1 mL solution for injection. It is supplied as a solution for injection. Enspryng is a recombinant humanised immunoglobulin G2 (IgG2) monoclonal antibody against the human interleukin-6 receptor (IL-6R), produced in Chinese hamster ovary cells by recombinant DNA technology. Satralizumab binds to soluble and membrane-bound human IL-6 receptor (IL-6R) and thereby prevents IL-6 downstream signalling through these receptors. IL-6 is a pleiotropic cytokine produced by a variety of cell types and is involved in diverse processes such as B-cell activation, differentiation of B-cells to plasmablasts and production of autoantibodies, Th17-cell activation and differentiation, T-regulatory cell inhibition, and changes in blood-brain barrier permeability.

Approved indications

Enspryng is indicated as monotherapy or in combination with immunosuppressive therapy (IST) for the treatment of adults with neuromyelitis optica spectrum disorders (NMOSD) who have an anti-aquaporin 4 antibody (AQP4)-IgG (also termed NMO-IgG) positive status.

Dosing overview

Enspryng is for subcutaneous use only. The recommended loading dose is 120 mg by subcutaneous injection every 2 weeks (first dose at week 0, second dose at week 2 and third dose at week 4) for the first three administrations. The recommended maintenance dose is 120 mg subcutaneously every 4 weeks. Enspryng is intended for long-term treatment. Enspryng 120 mg is administered by subcutaneous injection using a single-dose pre-filled syringe.

Key safety warnings

Enspryng administration should be delayed in patients with an active infection until the infection is controlled. If a patient develops a serious infection, administration of Enspryng should be interrupted until the infection is controlled. Vigilance for the timely detection of serious infection is recommended for patients receiving immunosuppressive agents, such as Enspryng, as signs and symptoms of acute inflammation may be lessened, due to suppression of the acute phase reaction. Live or live-attenuated vaccines should not be given concurrently with Enspryng as clinical safety has not been established. The interval between live vaccinations and initiation of Enspryng therapy should be in accordance with current vaccination guidelines regarding immunomodulatory/immunosuppressive agents. Decreases in neutrophil counts have occurred following treatment with Enspryng. Neutrophil counts should be monitored 4 to 8 weeks after the start of therapy and thereafter as clinically indicated. If the neutrophil count is below 1.0 × 10⁹/L and confirmed by repeat testing, Enspryng should be interrupted until the neutrophil count is >1.0 × 10⁹/L. Mild and moderate elevations of liver transaminases have been observed with Enspryng treatment. Most elevations were below 5× upper limit of normal and not treatment-limiting and resolved while continuing treatment with Enspryng. ALT and AST levels should be monitored every 4 weeks for the first 3 months of treatment, followed by every 3 months for one year, thereafter as clinically indicated.

Contraindications

Enspryng is contraindicated in patients with known hypersensitivity to satralizumab, Chinese hamster ovary cell proteins or any of the excipients listed in section 6.1.

Regulatory history

Enspryng (satralizumab) was approved by the TGA on 13 November 2020 for the treatment of adults with anti-aquaporin 4 antibody (AQP4)-IgG positive neuromyelitis optica spectrum disorders (NMOSD). ARTG 326047 for Enspryng satralizumab 120 mg/1 mL solution for injection in pre-filled syringe was first listed 2020-11-17. This medicinal product is subject to additional monitoring in Australia. This will allow quick identification of new safety information.