The development of romiplostim for patients with immune thrombocytopenia.

Comprised of peptide and carrier components in an overall structure superficially resembling an antibody, romiplostim is the prototype of a new class of protein therapeutics called peptibodies. Romiplostim (AMG 531, Nplate) was designed to evade the immune response to recombinant thrombopoietin and offer a new method of treatment for patients with immune thrombocytopenia (ITP), an "orphan" disease. In contrast with agents designed to suppress immune function or hinder the processes of platelet destruction, romiplostim works by stimulating the production of new platelets. It was proven to increase platelet counts, reduce the need for other ITP therapies and emergency treatments, and demonstrate an acceptable safety profile. In addition, romiplostim improves patient-reported outcomes and quality of life in those suffering from this rare disease.