Amgen has announced the launch of romiplostim (Nplate®) in the UK for the treatment of chronic immune (idiopathic) thrombocytopenic purpura (ITP) in splenectomised adult patients who are refractory to other treatments (e.g. corticosteroids, immunoglobulins). Romiplostim may also be considered as second line treatment for adult non-splenectomised patients where surgery is contra-indicated.

This drug is the first treatment specifically developed for adults with this condition, which is estimated to affect approximately 3600 adults each year in the UK. The approval was based on evidence from two placebo-controlled phase III studies which demonstrated that platelet counts were raised and sustained in 83% of both splenectomised and non-splenectomised patients treated with romiplostim.

The initial dose of romiplostim is 1 mcg/kg based on actual body weight given subceutaneously, once per week. The dose should then be increased by increments of 1 mcg/kg/week until the patient achieves a platelet count >/= 50 x 109/L. Please see attached SPC for further dosing details. The cost of each 250mcg vial is £482.