A group of physician-scientists conducted a study on the safety and efficacy of a new drug for patients with pyruvate kinase deficiency. This disorder is a rare type of anemia caused by a lack of pyruvate kinase, a key enzyme in red blood cell production and survival. According to the Dana-Farber Cancer Institute, there have been no disease-modifying treatments for the deficiency since the discovery of the disorder in the 1960s. Patients with pyruvate kinase
deficiency could only be treated for the symptoms of the disorder, most often with a splenectomy, cholecystectomy, and/or blood transfusions.
A study published in the New England Journal of Medicine has shown that the new oral drug, mitapivat, can raise hemoglobin levels in about half of study participants with pyruvate kinase deficiency. In a typical patient with this disorder, red blood cells break down in just a few weeks due to a lack of pyruvate kinase. Mitapivat works by activating this enzyme in red blood cells,
which helps prevent premature breakdown of the hemoglobin-carrying cells.
The breakdown of red blood cells and subsequent hemolytic anemia causes some patients to face severe complications, including gallstones, pulmonary hypertension, and cirrhosis. In addition, the medical procedures completed to relieve symptoms, such as splenectomies, have their own list of potential complications. Mitapivat provides an alternative by modifying the disease directly, rather than the symptoms of the anemia.
While mitapivat represents an important step forward in the treatment methodology for this rare genetic disease, further research needs to be conducted to determine the safety of the drug long-term and for children. Mitapivat also saw improvement in only half of participants, so continuing research is needed for a drug for those who do not respond to mitapivat.