When in the circulation, about 99% of both substances are bound to plasma proteins, namely to albumin and alpha-1-acid glycoprotein to equal amounts.The liver enzymes CYP2C8 and, to a lesser extent, CYP3A4, hydroxylate and dealkylate the active substance, thereby inactivating it. Besides, ACT-333679 is glucuronidized by the enzymes UGT1A3 and UGT2B7. The terminal half-life of selexipag is 0.8 to 2.5 hours, that of the active metabolite is 6.2 to 13.5 hours. History
The U.S. Food and Drug Administration (FDA) granted selexipag orphan drug status for PAH. It was approved by the FDA on 22 December 2015.In Europe, the drug was approved in May 2016. Society and culture
Economics
The expected price for the drug in the US is $160,000 to $170,000 per patient before rebates. References
External links
"Selexipag". Drug Information Portal. U.S. National Library of Medicine. Clinical trial number NCT03187678 for "Safety Study of the Switch From Oral Selexipag to Intravenous Selexipag in Subjects With Stable Pulmonary Arterial Hypertension" at ClinicalTrials.gov
Treatment
Although research is ongoing, currently there is no genetic-level cure for the myriad of mutations that cause the various presentations of hereditary spherocytosis. Common current management focuses on interventions prevent the body from inappropriately destroying the functional spherocytes produced by erythrocyte progenitor cells within the bone marrow. Typical treatment options include:

Splenectomy (operative): This is the operative removal of the entire spleen by a surgeon, thus stopping the extravascular hemolysis, but also removing the immune functions the spleen naturally provide to the body. Partial splenectomy (operative): This is when only a section of the spleen is removed, instead of the entire organ. The goal is to lower the extravascular hemolysis to a level compatible with homeostasis of the patient, while preserving the immune function of the spleens presence. Research on outcomes is currently ongoing, and is routine at childrens hospitals within the United States of America. Splenic ablation (interventional radiology): This option is non-operative, and is when an interventional radiologist (instead of a surgeon) uses radiologic techniques to coil or cauterize vasculature within the splenic circulation. There are various points in the circulatory pathway where the treatment can be applied to produces varying amounts of retained viability of the spleen, thus giving the option to attempt to preserve splenic immune function.All operative and interventional treaments require the immunization of HS patients against the influenza virus, SARS-CoV-2, and encapsulated bacteria such as Streptococcus pneumoniae and meningococcus. Antibiotics are no longer recommended for maintenance use, even in post-splenectomy HS patients.