DI-062 Romiplostim and eltrombopag in the treatment of Idiopatic Thrombocytopenic Purpura

Background Romiplostim and eltrombopag have a novel mechanism of action that expands treatment options for idiopathic thrombocytopenic purpura (ITP). Both have proven effective in increasing platelet counts in splenectomised patients. Purpose To describe their use in clinical practice. Materials and methods Descriptive observational study (January 2011-February 2013) of patients with refractory ITP treated with romiplostim or eltrombopag. Data were obtained from computerised medical history. Variables analysed: demographic data; previous treatments; splenectomy status; response to treatment, defined as platelet count ≥50 × 10 9 /L for at least 8 weeks; number of weeks with continuous response, clinically significant bleeding (grade 2–4 as classified by the World Health Organisation); need for rescue medication; adverse effect profile. Results Five patients were included (100% women) with a mean age of 62 ± 12.65 years, only one was splenectomised. All received at least two prior lines that included corticosteroids and intravenous immunoglobulins and four had also received rituximab. Four patients were treated with romiplostim as a first option, with a mean treatment duration of 23.5 ± 20.5 months (3–44 months) and one patient was treated for three months with eltrombopag in advance. The average dose of romiplostim was 4 mcg/kg (1–10 mcg/kg) administered subcutaneously weekly, two eltrombopag patients were initiated with oral 50 mg daily and then increased to 75 mg daily. During the study period, in the romiplostim group three patients achieved a durable response, reaching the target platelet count for an average of 48 ± 39.1 weeks. The other patient in this group received romiplostim for five months and did not reach the target despite receiving the maximum recommended dose (10 mcg/kg/week). She was changed to eltrombopag, with it reaching levels of 22 × 10 9 /L at the last check. The patient began with eltrombopag switched to romiplostim at 3 months of not meeting the target platelet count (maximum: 20 × 10 9 /L); currently receiving romiplostim dose of 3 mcg/kg/week to levels ≥50 × 10 9 /L for four weeks. In none of the cases was there clinically significant bleeding and no rescue treatment or hospitalisation were required. The safety profiles of both drugs were favourable because no adverse events related to its administration were detected. Conclusions Both drugs have proven effective and safe in patients with refractory ITP, can be considered therapeutic equivalents. We should take into account the weight of the patient; the oral administration of eltrombopag should also be considered. No conflict of interest.