Experts’ review: the emerging roles of romiplostim in immune thrombocytopenia (ITP)

ABSTRACT

Introduction

The management of ITP has in recent years been transformed from reliance on immunosuppressants and splenectomy to targeted therapy with thrombopoietin receptor agonists (TPO-RA) that directly stimulate platelet production in the bone marrow. This has reduced the long-term infective complications and toxicities associated with the use of potent immunosuppressants and splenectomy. The welltolerated romiplostim, itself a novel drug construct called peptibody, has established itself, alongside other TPO-RA as the preferred 2nd line therapy in major international guidelines on treatment of ITP.

Areas covered

This review summarizes the data from early licensing trials of romiplostim and discusses the real-world experience to date, the unexpected emerging data on treatment-free long-term remission achieved using TPO-RA, and the case for its early introduction in the therapeutic pathway. The emerging risk of thrombosis is also discussed.

Expert opinion

The use of romiplostim and other TPO-RA will be increasingly brought forward in the management pathway of ITP with the prospect of modifying the long-term outcome of the disease by increasing sustained treatment-free remission. With the prospect of several new targeted therapies been introduced into clinical practice, TPO-RA will likely be a key component of future combination therapies for difficult cases.

KEYWORDS:

• Immune thrombocytopenia
• ITP
• quality of life
• romiplostim
• thrombopoietin receptor agonists

Article highlights

• Clinical efficacy and patient tolerability of the TPO-RAs have been confirmed by both randomized control trials and real-world data over the last decade.

• International Guidelines have recommended their use earlier in the treatment pathway and this has been approved by the FDA.

• No new long-term treatment toxicities have emerged following prolonged treatment but there remains a potential increase in thrombosis in ‘at-risk’ individuals.

• Long-term treatment-free remission has been recognized in up to a third of responding patients.

• Improvement in Quality of Life is recognized in responding patients with a reduction in fatigue in many (but not all) patients.

Declaration of interest

A Newland has acted as a consultant for Amgen, Angle, Argenx, Grifols, GSK, Novartis and UCB Biosciences; he has also participated in advisory boards and/or as a speaker at medical education events sponsored by Amgen, Argenx, Grifols, GSK, Novartis and Roche; and, finally, he has received research support from Amgen, BMS, GSK, Novartis and Octapharma. V McDonald has received research support from Baxter and advisory fees from Alexion. F Chen has received research support and participated in advisory boards for Novartis. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

One of the reviewers declares research funding from Amgen and consultancy from Dova, Sobi, and Novartis. Another reviewer declares consultancy, speakers and ad board fees from Amgen and Novartis as an ITP expert and investigator of multiple trials. Peer reviewers on this manuscript have no other relevant financial relationships or otherwise to disclose.

Additional information

Funding

This paper is not funded.