Kristen Wheeden, Director of Development for the American Porphyria Foundation, discusses current treatment options for Porphyria, including some treatments in clinical trials.
Porphyria is caused by different inherited disorders in the synthesis of heme, the oxygen-binding component of red blood cells. Heme is also necessary for the metabolism of certain drugs and hormones by the liver. When the liver is unable to synthesise heme properly, toxic substances called porphyrin metabolites accumulate in the body, resulting in acute porphyria attacks. A small group of porphyria patients suffer recurrent acute attacks, which cause them chronic debilitating symptoms requiring constant hospital care.
Acute intermittent porphyria (AIP) is the most common form of acute porphyria. Patients suffering from acute attacks are treated using an infusion containing a form of heme called hemin, which suppresses the formation of the toxic metabolites.
Hemin will continue to be important treatment for Porphryia, but it’s only for acute treatment. For patients with recurrent attacks, no other curative treatment is available than liver transplantation.
The new drug candidate givosiran, developed by Alnylam Pharmaceuticals, has shown promising results in clinical trials. The study has been conducted in close, long-standing collaboration with Porphyria Centre Sweden, which has also provided the majority of the patients.
