Adult Immune (Idiopathic) Thrombocytopenic Purpura (ITP) is a chronic and potentially serious autoimmune disorder characterized by low platelet counts in the blood. In it, platelets are destroyed by the patient’s own immune system. ITP has historically been considered a disease of platelet destruction; however, recent data also suggest that the most prominent defect is the body’s inability to compensate for platelet destruction by increasing production. Newer approaches to treating ITP fous on increasing platelet production. The U.S. Food and Drug Administration has approved Nplate (romiplostim) in August 2008. This drug is the first product that directly stimulates the bone marrow to produce needed platelets in patients with a rare blood disorder that can lead to serious bleeding. Nplate revealed a number of adverse reactions, from bone-marrow abnormalities to dangerous blood clots. A Risk Evaluation and Mitigation Strategy (REMS) has been developed to address the risks of Nplate therapy. Under the Food and Drug Administration Amendments Act of 2007, FDA has determined that a REMS is necessary for the benefits of Nplate to outweigh the risks of the product. The REMS will include a Medication Guide for patients and requires that all prescribers and patients enroll in a special program to track the long term safety of Nplate therapy.
Where a splenectomy was not performed, a recent study presented at the 14th congress of the European Hematology Association from a study comparing romiplostim (Nplate®) to the medical standard of care (SOC) in non-splenectomised patients with chronic immune thrombocytopenic purpura (ITP).
The study involved 234 adults with chronic ITP, who were treated with either romiplostim (n=157) or medical SOC (n=77); the latter was prescribed by the investigator according to standard institutional practices or therapeutic guidelines; the only treatments not allowed were investigational agents or other thrombopoietic agents. A total of 13 (8%) patients who received romiplostim and 27 (35%) of those in the SOC group underwent splenectomy or discontinued the study prior to reporting a splenectomy. Furthermore, 12% and 27% experienced treatment failure (platelet counts ≤20,000 platelets/microL for four consecutive weeks, a major bleeding event, and/or a change in therapy due to intolerable side effects or bleeding symptoms) or discontinued the study, respectively.
Whether to use splenectomy always before Nplate remains an issue of debate. Perdomo notes and discusses this uncertianty;l however, splenectomy remains a less costly treatment that is as likely to produce equivalent therapeutic or diagnostic results
Perdomo J. Role of romiplostim in splenectomized and nonsplenectomized patients with immune thrombocytopenia. Immunotargets Ther. 2016;5:1-7. Published 2016 Feb 22. doi:10.2147/ITT.S80648
http://www.fda.gov/cder/foi/label/2008/125268lbl.pdf – Prescribing information
J. N. George, Management of Immune Thrombocytopenia — Something Old, Something New. November 11, 2010
N Engl J Med 2010; 363:1959-1961