RODEX

A multicentre, randomized, open-label study of romiplostim plus dexamethasone vs dexamethasone in patients with newly diagnosed primary immune thrombocytopenia.

In the RODEX trial, we are investigating Immune Thromobocytopenia (ITP), an autoimmune disease where the immune system attacks important blood cells called platelets, which are essential for normal clotting. Patients with ITP have reduced numbers of platelets and are at risk of bleeding. A course of corticosteroids (steroids – a man-made version of a hormone the body makes naturally) is recommended as the first treatment for adults with newly diagnosed ITP. Most patients with ITP respond to corticosteroids with a rise in platelet count, but improvements are usually temporary and the majority of patients will relapse (their ITP will return).

The objective of RODEX is to find out if a two-drug combination of corticosteroids (dexamethasone) plus a medicine called romiplostim is better than dexamethasone alone for treatment of ITP. Romiplostim is a thrombopoietin-receptor agonist (TPO-RA). Thrombopoietin (TPO) is the natural chemical that the body produces to tell the bone marrow to make more platelets. TPO-RAs are treatments that act like the body’s own TPO to increase the number of platelets that are produced.

RODEX will recruit up to 126 adult (18 years of age or older) patients at up to 30 hospital sites in the European Economic Area (EEA), including Spain and Italy and up to 15 sites in England, Wales and Scotland, UK.

Adult patients will be eligible to take part if they meet the eligibility criteria, including recently diagnosed ITP with a low platelet count and no previous ITP treatment. Participants will be randomly allocated by a computer to receive a course of dexamethasone alone (control arm) or dexamethasone plus romiplostim (investigational arm).  They will be followed up for up to 2 years (screening, day 1, week 8, week 12, month 6, month 12, and end of Study Visit) to find out if dexamethasone plus romiplostim can improve long-term treatment response and avoid bleeding. Study treatments and visits will vary slightly dependent on the study arm.

Study leads

Chief Investigator and Spain National Coordinating Investigator
Dr Eva Mingot, FISEVI, Spain

UK National Coordinating Investigator
Dr Charlotte Bradbury, Bristol University, England, UK

Italy National Coordinating Investigator
Dr Monica Carpenedo, Ospedale Luigi Sacco, Ematologia e Medicina Trasfusionale, Milan, Italy

UK Senior Trial Manager/Study Lead
Ian Thomas, Centre for Trials Research at Cardiff University, Wales, UK
Email: ThomasIF@cardiff.ac.uk

Results

The data from the trial is currently being analysed. Interim results were published at the 67th American Society of Haematology (ASH) Annual Meeting December 6-9, 2025, Florida, USA. We will share the full results, in lay format, here when they are available.