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.