Eculizumab
In 2007, the drug eculizumab was approved for the treatment of PNH. Prior to eculizumab, the median life expectancy of an individual with PNH was approximately 10 years. Since that time, short and mid-term studies of patients on eculizumab demonstrate that the drug returns the patient to a normal life expectancy, improves quality of life, and decreases the need for blood transfusions.Eculizumab is controversial due to its high cost, as it is among the most expensive pharmaceuticals in the world, with a price of US$440,000 per person per year. Eculizumab is a humanized monoclonal antibody that acts as a terminal complement inhibitor. The drug interferes with the formation of the membrane attack complex in erythrocytes by binding to C5, compensating for the loss of protective function that results from CD59 deficiency. This alleviates the primary source of intravascular hemolysis, but it does not reduce the opsonization of erythrocytes caused by CD55 deficiency, so patients who receive this medication often still experience mild to moderate hemolysis. The U.S. Food and Drug Administration (FDA) has issued a black-box warning as those who take the medication have a 1,000 to 2,000-fold greater risk of invasive meningococcal disease. People on eculizumab are strongly advised to receive meningococcal vaccination at least two weeks prior to starting therapy and to consider preventative antibiotics for the duration of treatment. Pegcetacoplan
Pegcetacoplan was approved for medical use in the United States in May 2021. Epidemiology
PNH is rare, with an annual rate of 1-2 cases per million. The prognosis without disease-modifying treatment is 10–20 years.
Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired, life-threatening disease of the blood characterized by destruction of red blood cells by the complement system, a part of the bodys innate immune system. This destructive process occurs due to deficiency of the red blood cell surface protein DAF, which normally inhibits such immune reactions. Since the complement cascade attacks the red blood cells within the blood vessels of the circulatory system, the red blood cell destruction (hemolysis) is considered an intravascular hemolytic anemia. Other key features of the disease, such as the high incidence of venous blood clot formation, are incompletely understood.PNH is the only hemolytic anemia caused by an acquired (rather than inherited) intrinsic defect in the cell membrane (deficiency of glycophosphatidylinositol or GPI) leading to the absence of protective exterior surface proteins that normally attach via a GPI anchor. It may develop on its own ("primary PNH") or in the context of other bone marrow disorders such as aplastic anemia ("secondary PNH"). Only a minority of affected people  have the telltale red urine in the morning that originally gave the condition its name.Allogeneic bone marrow transplantation is the only cure, but has significant rates of additional medical problems and death. The monoclonal antibody eculizumab reduces the need for blood transfusions and improves quality of life for those affected by PNH. Eculizumab dramatically alters the natural course of PNH, reducing symptoms and disease complications as well as improving survival to the extent that it may be equivalent to that of the general population.