Long‐term treatment with romiplostim in patients with chronic immune thrombocytopenia: safety and efficacy

Abstract

SummaryRomiplostim was effective, safe, and well-tolerated over 6-12 months of continuous treatment in Phase 3 trials in patients with immune thrombocytopenia (ITP). This report describes up to 5 years of weekly treatment with romiplostim in 292 adult ITP patients in a long-term, single-arm, open-label study. Outcome measures included adverse events (including bleeding, thrombosis, malignancy, and reticulin/fibrosis), platelet response (platelet count >50 9 10 9 per litre), and the proportion of patients requiring rescue treatments. Treatment-related serious adverse events were infrequent and did not increase with longer treatment. No new classes of adverse events emerged. Thrombotic events occurred in 6Á5% of patients and were not associated with platelet count. Median platelet counts of 50-200 9 10 9 per litre were maintained with stable doses of romiplostim (mean 5-8 lg/kg; generally self-administered at home) throughout the study. A platelet response was achieved at least once by 95% of patients, with a platelet response maintained by all patients on a median 92% of study visits. There was a low rate of bleeding and infrequent need for rescue treatments. In conclusion, this study demonstrated that romiplostim was safe and well-tolerated over 614 patient-years of exposure in ITP patients, and that efficacy was maintained with stable dosing for up to 5 years of continuous treatment.

Is ITP a thrombophilic disorder?

“…From the whole population of patients exposed to romiplostim in all 13 company-sponsored trials, a subanalysis was carried out by Kuter et al on 291 patients who entered a long-term study after the completion of a previous ITP study with romiplostim [34]. Patients were followed for up to 5 years (mean exposure time 2.11 years) to assess safety and efficacy.…”

The biology of thrombopoietin and thrombopoietin receptor agonists

“…Into each arm of the IgG heavy chain are inserted two identical 14-amino acid peptides with the sequence IEGPTLRQWLAARA [66]. Glycine linker regions are also shown [66] romiplostim in most studies was 4-5 lg/kg [45,[71][72][73], this author recommends starting at 3 lg/kg in most settings and increasing by 2 lg/kg weekly until the desired platelet count is attained. In more urgent settings even higher starting doses, including the maximal dose of 10 lg/kg, may be used to determine rapidly if this agent will be effective in the patient.…”

“…This is based upon a large number of clinical trials that have shown that the administration of either TPO receptor agonist increases the platelet count (Fig. 6), decreases the need for rescue medications, decreases the need for other ITP therapies such as corticosteroids, may avoid the need for splenectomy, improves the quality of life, and markedly decreases the rate of bleeding [45,71,[87][88][89].…”

“…Almost all these data come from ITP patients studied in two recent longterm safety studies [71,87]. Observed adverse events…”

Primary antiphospholipid syndrome patient associated with refractory thrombocytopenia and Factor V Leiden mutation treated with eltrombopag

“…Ancak TPO reseptor agonistleri ile ilgili son yapilan çalişmalarda; İTP hastalarinda TPO reseptor agonistleri kullanimi sonucu venöz tromboemboli gelişimi açisindan plasebo grubuna göre anlamli fark saptanmamiştir [19,21,22,23].…”