Today, the U.S. Food and Drug Administration granted approval to Givlaari (givosiran) for the treatment of adult patients with acute hepatic porphyria, a genetic disorder resulting in the buildup of toxic porphyrin molecules which are formed during the production of heme (which helps bind oxygen in the blood). "This buildup can cause acute attacks, known as porphyria attacks, which can lead to severe pain and paralysis, respiratory failure, seizures and mental status changes. These attacks occur suddenly and can produce permanent neurological damage and death," said Richard Pazdur, M.D., director of the FDA’s Oncology Center of Excellence and acting director of the Office of Oncologic Diseases in the FDA's Center for Drug Evaluation and Research. "Prior to today's approval, treatment options have only provided partial relief from the intense unremitting pain that characterizes these attacks. The drug approved today can treat this disease by helping to reduce the number of attacks that disrupt the lives of patients." The approval of Givlaari was based on the results of a clinical trial of 94 patients with acute hepatic porphyria. Patients received a placebo or Givlaari. Givlaari’s performance was measured by the rate of porphyria attacks that required hospitalizations, urgent health care visits or intravenous infusion of hemin at home. Patients who received Givlaari experienced 70% fewer porphyria attacks compared to patients receiving a placebo.