Amgen Inc. said it will discuss the proposed Biologic License Application (BLA) for romiplostim, an investigational thrombopoietin mimetic peptibody, for the treatment of thrombocytopenia in adult patients with chronic immune (idiopathic) thrombocytopenic purpura (ITP) at the Oncologic Drugs Advisory Committee (ODAC).
Patients with chronic ITP, a serious autoimmune disorder characterized by low platelet counts in the blood (thrombocytopenia) face the risk of bleeding events. Treatment of thrombocytopenia in adult patients with chronic ITP is considered an unmet medical need by the US Food and Drug Administration (FDA) and has received orphan drug designation.
The proposed indication for romiplostim submitted to the FDA is for the treatment of thrombocytopenia in adults with chronic ITP who have not undergone splenectomy (removal of the spleen) and have had an inadequate response or are intolerant to corticosteroids and/or immunoglobulins; or patients who have had their spleen removed and have an inadequate response to the procedure.
"By stimulating platelet production, romiplostim represents a potentially new approach to the management of chronic ITP," said David J. Kuter, M.D., D. Phil., Chief of Hematology, Massachusetts General Hospital, Boston. "Romiplostim would be an important treatment option for adult patients affected by this disease."
Amgen filed for regulatory approval of romiplostim with the FDA in October 2007 and was granted priority review. Regulatory filings in the European Union (EU), Canada and Australia were also filed in 2007 and are currently under review. Orphan designation was granted for romiplostim in 2003 by the FDA. An orphan disease is defined as a condition that affects fewer than 200,000 people nationwide. Romiplostim also has received orphan designation for the proposed indication in the EU (2005), Switzerland (2005) and Japan (2006).
Romiplostim is an investigational protein (peptibody), containing two components--a "binding" peptide linked to a larger protein. Developed by Amgen, peptibodies are engineered therapeutic molecules that can bind to human drug targets and contain peptides linked to the constant domains of antibodies. Romiplostim works similarly to thrombopoietin (TPO), a natural protein in the body. The binding peptide component of romiplostim stimulates the TPO receptor, which is necessary for growth and maturation of bone marrow cells that produce platelets.