Eculizumab
Eculizumab, sold under the brand name Soliris among others, is a recombinant humanized monoclonal antibody used to treat paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS), generalized myasthenia gravis, and neuromyelitis optica. In people with PNH, 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 drug approved for each of its uses, and its approval was granted based on small trials. It is given by intravenous infusion. Side effects include a risk for meningococcal infections and it is only prescribed to those who have enrolled in and follow a risk evaluation and mitigation strategy, which involves counseling people and ensuring that they are vaccinated. It is a humanized monoclonal antibody functioning as a terminal complement inhibitor. It is developed, manufactured, and marketed by Alexion Pharmaceuticals. Medical uses Eculizumab is used to treat atypical hemolytic uremic syndrome (aHUS) and paroxysmal nocturnal hemoglobinuria (PNH). For people with PNH, 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 has also been explored as a treatment for CD55 deficiency, also known as CHAPLE syndrome, a rare genetic disorder of the immune system. With approval for compassionate off-label use, Kurolap and colleagues treated patients with the drug and found it to have positive clinical and laboratory outcomes over an 18-month period. Adverse effects Eculizumab carries a black box warning for the risk of meningococcal infections and can only be prescribed by doctors who have enrolled in and follow a risk evaluation and mitigation strategy required by the FDA, which involves doctors counseling people to whom they are prescribing the drug, giving them educational materials, and ensuring that they are vaccinated, all of which must be documented. 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