Bertrand Godeau

How I treat immune thrombocytopenia: the choice between splenectomy or a medical therapy as a second-line treatment

The paradigm for managing primary immune thrombocytopenia (ITP) in adults has changed with the advent of rituximab and thrombopoietin receptor agonists (TPO-RAs) as options for second-line therapy. Splenectomy continues to provide the highest cure rate (60%-70% at 5+ years). Nonetheless, splenectomy is invasive, irreversible, associated with postoperative complications, and its outcome is currently unpredictable, leading some physicians and patients toward postponement and use of alternative approaches. An important predicament is the lack of studies comparing second-line options to splenectomy and to each other. Furthermore, some adults will improve spontaneously within 1-2 years. Rituximab has been given to more than 1 million patients worldwide, is generally well tolerated, and its short-term toxicity is acceptable. In adults with ITP, 40% of patients are complete responders at one year and 20% remain responders at 3-5 years. Newer approaches to using rituximab are under study. TPO-RAs induce platelet counts > 50 000/μL in 60%-90% of adults with ITP, are well-tolerated, and show relatively little short-term toxicity. The fraction of TPO-RA-treated patients who will be treatment-free after 12-24 months of therapy is unknown but likely to be low. As each approach has advantages and disadvantages, treatment needs to be individualized, and patient participation in decision-making is paramount.

Agonistes du récepteur de la thrombopoïétine et prise en charge des thrombopénies. Actualités et perspectives

La thrombopoietine (Tpo) est la principale cytokine impliquee dans la proliferation, la differenciation et la maturation de la lignee megacaryocytaire. Des peptides ou de petites molecules non peptidiques n’ayant pas d’homologie de sequence avec la Tpo endogene mais capables de mimer l’effet de la Tpo endogene en se fixant a son recepteur ont ete developpes et ont atteint le stade du developpement clinique leur permettant d’obtenir une autorisation de mise sur le marche dans le purpura thrombopenique immunologique (PTI). Plusieurs essais therapeutiques multicentriques ont en effet prouve leur grande efficacite dans cette indication. Le caractere « suspensif » de ces traitements, leur cout particulierement eleve et l’absence de donnees permettant d’affirmer leur inocuite en cas d’administration tres prolongee ne reglent toutefois pas pour autant tous les problemes poses par le traitement du PTI chronique. La poursuite d’essais therapeutiques et d’analyses pharmaco-economiques est donc necessaire afin de mieux cerner la place de ces traitements.