Taiwan Biotech PharmaEssentia Gets FDA Approval for Rare Blood Disease



The U.S. Food and Drug Administration last Friday granted approval for Besremi (ropeginterferon alfa-2b-njft) injection for treatments of adults with polycythemia vera, a blood infection that brings about the overproduction of red blood cells. The excess cells cause thickening of the blood, slowing blood flow and catalyzing the risk of blood clots.

“Over 7,000 rare diseases affect more than 30 million people in the United States. Polycythemia vera affects approximately 6,200 Americans each year,” noted Ann Farrell, M.D., director of the Division of Non-Malignant Hematology in the FDA’s Center for Drug Evaluation and Research.


Besremi is the first-ever FDA-approved drug for polycythemia vera that patients can take irrespective of their treatment history and the first interferon therapy explicitly approved for polycythemia vera.


Treatment for polycythemia vera includes phlebotomies (a procedure that discharges excess blood cells through a needle in a vein) as well as drugs to lower the number of blood cells; Besremi is one of these medications. The drug is said to work by attaching to specific receptors in the body, bringing about a chain reaction that ensures the bone narrow lower production of red blood cells. Besremi is a long-acting medication that is administered to patients under the skin once every two weeks. If Besremi can lower excess blood cells and maintain normal levels for at least a year, then dosing frequency may be decreased to once every four weeks.


The effectiveness and safety of Besremi were put into test in a multicenter, single-arm trial that spanned 7.5 years. In this trial, 51 adults with polycythemia vera received Besremi for an average of about five years. The effectiveness of the drug was evaluated by assessing the number of patients who achieved a complete hematological response, which implied that patients had a red blood cell volume of less than 45% without a recent phlebotomy, normal white cell counts and platelet counts, a normal spleen size, and zero blood clots. Generally, 61% of patients boasted of a complete hematological response.


Besremi can bring about elevation of liver enzyme, reduced levels of white blood cells, reduced levels of platelets, itching, fatigue, pains in the joints, muscle pain, flu-like illness, and upper airway infection. Side effects may also include depression, urinary tract infection, and transient ischemic attacks (stroke-like attacks).


Interferon alfa products like Besremi may bring about or worsen autoimmune, ischemic (inadequate blood flow to a part of the body), neuropsychiatric autoimmune, ischemic, and infectious diseases, which could lead to adverse or life-threatening effects.


Patients who must not take Besremi include those who are allergic to the medication, those with autoimmune disease or a history of autoimmune disease, patients with liver disease those with a severe psychiatric disorder, or a history of a severe psychiatric disorder, and immunosuppressed transplant recipients. Pregnant women should be subjected to a pregnancy test before using Besremi to prevent fetal harm.

Besremi got orphan drug designation for this indication. Orphan drug designation ensures incentives to assist and boost drug development for rare diseases.

The FDA granted the approval of Besremi to PharmaEssentia Corporation.