How do Fc receptor antagonists work?
Fc receptor antagonists are medications used to treat generalized myasthenia gravis, a neuromuscular disease that causes skeletal muscle fatigue and weakness. Fc receptor antagonists are used to treat adults with myasthenia gravis, who have anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibodies.
Nerve cells (neurons) in neuromuscular junctions produce acetylcholine, a chemical messenger (neurotransmitter) that makes muscles contract. Acetylcholine works by activating protein molecules in neuromuscular junctions including acetylcholine receptor and muscle-specific tyrosine kinase.
Myasthenia gravis is an autoimmune disorder in which the immune system produces immunoglobulin G (IgG) auto antibodies to AChR and/or MuSK, which destroy these molecules, preventing normal neurotransmission, which results in muscle weakness and fatigue. Neonatal Fc receptor is a molecule that binds to, transports and recycles IgG, including the auto antibodies, prolonging their life.
Fc receptor antagonists are lab-produced human antibodies that bind to neonatal Fc receptors blocking their activity. This restores normal degradation of IgG antibodies, brings down circulating IgG levels and reduces their autoimmune activity, while avoiding widespread immunosuppression.
How are Fc receptor antagonists used?
Fc receptor antagonists are administered as an intravenous or subcutaneous infusion to treat myasthenia gravis in adults who are positive for anti-acetylcholine receptor or anti-muscle-specific tyrosine kinase antibodies.
What are the side effects of Fc receptor antagonists?
Side effects of Fc receptor antagonists may include the following:
- Respiratory tract infections
- Headache
- Administration site reactions
- Any infection
- Diarrhea
- Nausea
- Abdominal pain
- Fever (pyrexia)
- Hypersensitivity reactions
- Urinary tract infection
- Abnormal skin sensations (paresthesia)
- Muscle pain (myalgia)
- Joint pain (arthralgia)
- Herpes simplex infection
- Serious infections
Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.
What are names of some Fc receptor antagonists?
Generic and brand names of Fc receptor antagonists include:
- efgartigimod alfa-fcab
- efgartigimod alfa/hyaluronidase-qvfc
- efgartigimod/hyaluronidase SC
- rozanolixizumab
- Rystiggo
- Vyvgart
- Vyvgart Hytrulo
