Which specific antibodies must be present for Epysqli approval in myasthenia gravis?

Epysqli (eculizumab-sbja) is a complement inhibitor approved for generalized myasthenia gravis (gMG). The FDA approval is specifically limited to adult patients who are anti-acetylcholine receptor (AChR) antibody positive. This means that before starting Epysqli, your doctor must confirm that you have these antibodies through a blood test. Other antibody types, such as anti-LRP4 or anti-MuSK, do not qualify for this treatment under the current approval.

What the research says

The FDA label for Epysqli explicitly states that it is indicated for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) antibody positive ². This requirement is based on the mechanism of action: eculizumab blocks complement protein C5, and anti-AChR antibodies are known to activate the complement pathway, leading to damage at the neuromuscular junction ⁹. While other antibodies like anti-LRP4 and anti-Titin can also activate complement, the approval is restricted to AChR-positive patients ⁹. A meta-analysis of efgartigimod, a different drug, found no significant difference in treatment response between AChR-positive and AChR-negative subtypes, but that does not apply to Epysqli's approval criteria ¹. Case reports have described successful treatment with eculizumab in patients with both anti-AChR and anti-LRP4 antibodies, but these are off-label uses and not covered by the FDA indication ⁹.

What to ask your doctor

• Have I been tested for anti-acetylcholine receptor (AChR) antibodies?
• If I am AChR antibody positive, is Epysqli a treatment option for my generalized myasthenia gravis?
• What are the risks and benefits of Epysqli compared to other treatments for my condition?
• If I have other antibodies (like anti-LRP4 or anti-MuSK), are there any approved treatments for me?