FDA Approves Nplate to Treat ITP

The FDA recently approved Amgen’s Nplate to treat Idiopathic Thrombocytopenic Purpura (ITP), a disorder causing low platelet counts and uncontrollable bleeding. Nplate is a fusion protein containing both peptide and antibody characteristics, which helps to raise and regulate platelet levels in chronic ITP patients. It is the first drug to provide a long-term treatment option for the estimated 60,000 chronic ITP patients in the U.S. The approval of Nplate was based on two clinical studies where chronic ITP patients successfully raised their platelet counts and sustained them for the 6 month study. Despite these positive results, there is evidence that Nplate may have some adverse side effects.

One concern is that Nplate may cause fibrous deposits in the bone marrow. Additionally, patients who discontinue using Nplate may have a lower platelet count after than before they started using it. Blood clots may also form due to excessive platelet count increases.

Nplate works by stimulating the thrombopoietin (TPO) receptor which is involved with the development of bone marrow cells that make platelets. One study showed that Nplate may increase risk of developing acute leukemia (a type of blood cancer) in patients who already have a condition called myelodysplasia. Myelodysplasia is a blood disorder connected to ineffective blood cell production. It puts patients at a higher risk of cell transformation leading to acute leukemia. In the study, 44 patients with myelodysplasia received the drug Nplate. Of them, 4 got leukemia. Further research is needed to determine if Nplate caused the development of this cancer.

Do you have chronic ITP? Do you have experience with Nplate? If so, by what means? Have you found any alternative treatments? Share your experiences!