How Do Complement Inhibitors Work?

Reviewed on 9/5/2023

How do complement inhibitors work?

Complement inhibitors are a type of immunotherapy used in the treatment of many inflammatory conditions, including lung and multiorgan inflammation caused by COVID-19 disease. Complement inhibitors work by inhibiting the activity of the complement system, a part of the body’s innate immune system.

The complement system consists of multiple circulating proteins in the blood that enhance the ability of antibodies and phagocytes to attack and remove pathogens. The complement proteins also play a role in the destruction of the body’s cells in certain blood disorders, inflammatory conditions and autoimmune diseases.

The complement system is activated when the proteins are cleaved into their active fragments, which activate a cascade of inflammatory actions that results in destruction of cells perceived to be harmful to the body. Complement inhibitors bind to the proteins and prevent their cleavage and downstream activation of the complement system.

Most complement inhibitors are lab-produced monoclonal antibodies designed to act against specific complement proteins, and administered as intravenous infusions. A few are small molecule oral drugs, or protein fragments (peptides) infused subcutaneously, which also inhibit the complement system’s activation.

How are complement inhibitors used?

Complement inhibitors may be administered as oral capsules, intravenous infusions, subcutaneous infusions, or intravitreal injections into the eye.

The uses of complement inhibitors include:

  • Adult:
  • FDA-approved:
    • Active antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis
    • Paroxysmal nocturnal hemoglobinuria
    • Hemolytic uremic syndrome
    • Generalized myasthenia gravis in patients who are anti-acetylcholine receptor (AchR) antibody positive
    • Neuromyelitis optica spectrum disorder (NMOSD) in adults who are anti-aquaporin-4 (AQP4) antibody positive
    • Geographic atrophy (intravitreal)
    • CD55-deficient protein-losing enteropathy (PLE), also known as CHAPLE disease
    • Atypical hemolytic uremic syndrome (aHUS)
    • Supplemental doses following plasma exchange (PE), plasmapheresis (PP), and IV immunoglobulin (IVIg)
    • Cold agglutinin disease
    • COVID-19 disease (Emergency Use Authorization)
  • Off-label:
    • Degos disease
  • Orphan designations
    • Dermatomyositis
    • Idiopathic membranous glomerular nephropathy
    • Renal transplantation: prevention of delayed graft function
    • Shiga-Toxin producing Escherichia coli hemolytic uremic syndrome
    • CD55-deficient protein-losing enteropathy (PLE), also known as CHAPLE disease
  • Pediatric:
  • FDA-approved:
    • Hemolytic uremic syndrome
    • Supplemental doses after plasma exchange (PE) or plasma infusion (PI)
    • Atypical hemolytic uremic syndrome (aHUS)
    • Paroxysmal nocturnal hemoglobinuria

What are the side effects of complement inhibitors?

Side effects of complement inhibitors include the following:

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 complement inhibitors?

Generic and brand names of complement inhibitors include:

  • avacopan
  • eculizumab
  • Empaveli
  • Enjaymo
  • Gohibic
  • pegcetacoplan
  • pozelimab
  • pozelimab-bbfg
  • ravulizumab
  • ravulizumab-cwvz
  • Soliris
  • sutimlimab
  • sutimlimab-jome
  • Tavneos
  • Ultomiris
  • Veopoz
  • vilobelimab
  • zilucoplan

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