A new treatment reduced much more than any other the symptoms of myelofibrosis

Myelofibrosis is a rare spontaneous disease that affects bone marrow progenitor cells. In 2005 researchers discovered that 60% of patients carry an acquired mutation of JAK2 gene in blood cells. The disease is characterized by a progressive replacement of bone marrow with fibrosis, which prevents the proper production of blood cells. Symptoms are heterogeneous and affect deeply the quality of life of people who suffer it. The most common are anemia, weight loss, excessive sweating accentuated at night and abdominal discomfort due to spleen enlargement. Moreover, in some cases myelofibrosis may evolve to an acute leukemia. An article in New England Journal of Medicine (NEJM) compares the best treatment available so far for myelofibrosis with ruxolitinib, a new therapy that has proven far more effective. Dr. Francisco Cervantes, from the Hematology Service of Hospital Clínic of Barcelona and team leader of the Institut Biomedical Research August Pi i Sunyer (IDIBAPS) Hematological oncology group, is one of the authors of the work that will change the treatment of this disease.

The article in NEJM reports the results of an international study in which 219 patients with high-risk or intermediate-2 risk myelofibrosis randomly received ruxolitinib or the conventional treatment considered more appropriate for the patient's symptoms. Ruxolitinib is an oral administration JAK2 inhibitor. Alternative treatment was, in most cases, hydroxyurea, an oral chemotherapy. Dr. Francisco Cervantes included patients in the study and participated actively in its design and writing of the article. He is also the author of the international classification of the disease, which determines the stratification of patients and is currently used worldwide.

The spleen is involved in hematopoiesis during fetal development. In patients with myelofibrosis the production of blood cells disappears from the bone marrow due to fibrosis and, secondarily, the spleen is gradually enlarged up to several pounds of weight (which is known by the medical term splenomegaly), causing significant discomfort in the abdomen. In addition, anemia, weight loss and profuse sweating also significantly affect the lives of patients with myelofibrosis. The cure of this disease can only be achieved through a bone marrow transplant. However, this option means significant risks, including a mortality around 35%, so it is considered only in very rare young patients with high-risk disease and a short life expectancy. It is therefore important to have a palliative treatment that erases or at least improves the symptoms of the disease.

The study results show that ruxolitinib was significantly more effective in reducing splenomegaly and constitutional symptoms due to myelofibrosis (basically, profuse sweating and weight loss) than conventional treatment. Importantly, its beneficial effect was durable. However, it rarely improved anemia. While ruxolitinib has no curative potential against bone marrow fibrosis, its intense palliative effect and durability have led to the approval of the drug by the American Food and Drug Administration (FDA) for the treatment of high-risk or intermediate risk-2 myelofibrosis with splenomegaly, a situation for which treatments were largely ineffective. The drug is now awaiting approval by the European Medicines Agency (EMA).