Eculizumab

Eculizumab, sold under the brand name Soliris among others, is a recombinant humanized monoclonal antibody used to treat paroxysmal nocturnal hemoglobinuria, atypical hemolytic uremic syndrome, generalized myasthenia gravis, and neuromyelitis optica. In people with paroxysmal nocturnal hemoglobinuria, it reduces both the destruction of red blood cells and need for blood transfusion, but does not appear to affect the risk of death. Eculizumab was the first medication approved for each of its uses, and its approval was granted based on small trials. It is given by intravenous infusion. It is a humanized monoclonal antibody functioning as a terminal complement inhibitor. It binds to the complement C5 protein and inhibits activation of the complement system, a part of the body's immune system. This binding prevents the breakdown of red blood cells in the bloodstream (intravascular hemolysis) in people with paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome.

The most frequently reported adverse reactions for people with paroxysmal nocturnal hemoglobinuria include headache, nasopharyngitis (common cold), back pain and nausea The most frequently reported adverse reactions for people with atypical hemolytic uremic syndrome include headache, diarrhea, hypertension, upper respiratory infection, abdominal pain, vomiting, nasopharyngitis, anemia, cough, swelling of lower legs or hands, nausea, urinary tract infections and fever

Eculizumab (Soliris) is developed, manufactured, and marketed by Alexion Pharmaceuticals.

Eculizumab is indicated for the treatment of people with paroxysmal nocturnal hemoglobinuria to reduce hemolysis; and the treatment of people with atypical hemolytic uremic syndrome to inhibit complement-mediated thrombotic microangiopathy.

Eculizumab is used to treat atypical hemolytic uremic syndrome (aHUS) and paroxysmal nocturnal hemoglobinuria (PNH). For people with paroxysmal nocturnal hemoglobinuria, it improves quality of life and decreases the need for blood transfusions but does not appear to affect the risk of death. It does not appear to change the risk of blood clots, myelodysplastic syndrome, acute myelogenous leukemia, or aplastic anemia. Eculizumab is also used to treat neuromyelitis optica spectrum disorder in adults who are anti-aquaporin-4 (AQP4) antibody positive.

Eculizumab carries a boxed warning for the risk of meningococcal infections caused by Neisseria meningitidis.

Eculizumab inhibits terminal complement activation and therefore makes people vulnerable to infection with encapsulated organisms. Life-threatening and fatal meningococcal infections have occurred in people who received eculizumab. People receiving eculizumab have up to 2,000 times greater risk of developing invasive meningococcal disease. Due to the increased risk of meningococcal infections, meningococcal vaccination is recommended at least 2 weeks prior to receiving eculizumab, unless the risks of delaying eculizumab therapy outweigh the risk of developing a meningococcal infection, in which case the meningococcal vaccine should be administered as soon as possible. Both a serogroup A, C, W, Y conjugate meningococcal vaccine and a serogroup B meningococcal vaccine are recommended for people receiving eculizumab. Receiving the recommended vaccinations may not prevent all meningococcal infections, especially from nongroupable N. meningiditis. In 2017, it became clear that eculizumab has caused invasive meningococcal disease despite vaccination, because it interferes with the ability of antimeningococcal antibodies to protect against invasive disease.

The drug's labels also carry warnings of severe anemia arising from the destruction of red blood cells as well as severe cases of blood clots forming in small blood vessels.