Novel generalised myasthenia gravis treatment approved

The European Commission (EC) has authorised ZILBRYSQ^® (zilucoplan)▼ as the first once-daily subcutaneous (SC), targeted peptide inhibitor of complement component 5 (C5) inhibitor for generalised myasthenia gravis (gMG).

It is also the only C5 inhibitor approved for self-administration by adult patients who are AChR antibody-positive with this disease.

Approval of the generalised myasthenia gravis treatment

Zilucoplan is approved as an add-on to standard therapy for adults who are anti-acetylcholine receptor (AChR) antibody-positive with this rare autoimmune disease, according to the European Medicines Agency (EMA).

The approved treatment administration method is based on data from the RAISE Phase III study, which demonstrated that zilucoplan delivered rapid, consistent, clinically meaningful and statistically significant improvements in outcomes at week 12, the final week of the study.

Patients were randomised in a 1:1 to receive daily subcutaneous injections of 0.3mg/kg zilucoplan or placebo for 12 weeks. Generalised myasthenia gravis patients who completed the RAISE trial had the option to take part in the open-label RAISE-XT extension study, UCB stated.

Unlike monoclonal antibody C5 inhibitors, as a peptide, the small molecule treatment zilucoplan can be used along with intravenous immunoglobulin and plasma exchange. Based on data from the Phase III trial, this means supplemental dosing is not required.

In addition to the EC’s approval of zilucoplan, other regulatory decisions regarding treatments for adults with generalised myasthenia gravis include: “a positive European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) opinion from European Medicines Agency for [UCB’s] FcRn blocker rozanolixizumab, and approvals for both zilucoplan and rozanolixizumab in the US and Japan,” explained Jean-Christophe Tellier, CEO of UCB.

The mechanism of action for the humanised IgG4 monoclonal antibody rozanolixizumab is that it reduces circulating IgG by blocking the interaction of FcRn and Immunoglobulin G (IgG). Therefore, this lowers the concentration of pathogenic IgG autoantibodies in the body, according to details shared in a paper published in the Lancet.

▼ This medicinal product is subject to additional monitoring.