Background Romiplostim was approved in 2009 to treat adult splenectomised patients with chronic Idiopathic Thrombocytopenic Purpura (ITP) when refractory to other treatment. It is also considered second-line treatment in non-splenectomised patients in which surgery is not advised.

Purpose To determine the effectiveness and safety of romiplostim in patients with ITP who did not respond to 1st line or later treatments.

Material and methods Observational and retrospective study. All patients treated with the drug from January 2009 to February 2014 were included. Data collected included demographic, clinical and analytical information, as well as dates of administration of the drug and dose administered.

Results 7 patients diagnosed with ITP and not responding to previous treatment lines were included, three splenectomised and four non-splenectomised. Previous lines of therapy varied among patients and included: nonspecific immunoglobulins, corticosteroids, danazol, rituximab and eltrombopag. Platelet count (PC) at the start of treatment was less than 50 × 10⁹/l in 6 patients and higher in 1 patient. Three patients received fewer than six doses, so it was not possible to assess platelet response. The remaining four patients started treatment at a dose of 1 mcg/kg, maximum doses received ranged from 5 to 10 mcg/kg. In the four patients who received more than six doses of the drug response was variable. The percentage of time with sustained PC in one patient was only 19% of the treatment time (99 weeks follow-up) while in the other three it was 73%, 85% and 97%. One patient had PC of 150 × 10⁹/l for four weeks with no dose reduction.

Conclusion Romiplostim was prescribed according to approved use in all cases except for treatment discontinuation in the case of no response. No serious adverse effects were reported. Effectiveness was very variable. A protocol for use including conditions for discontinuation in case of no response could improve use of the drug in our institution.

References and/or acknowledgements No conflict of interest.