Is Eltrombopag/Eltrombopag effective in treating thrombocytopenia?

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by a low platelet count and an increased risk of bleeding. Eltrombopag/Eltrombopag is a small molecule, oral, non-peptide thrombopoietin receptor agonist (TPO-RA) widely approved for the treatment of patients with chronic immune thrombocytopenia aged >1 year, chronic hepatitis C and thrombocytopenia (interferon therapy is allowed), and patients with severe aplastic anemia who have an inadequate response to immunosuppressive therapy.

Eltrombopag increases platelet production by binding to the transmembrane region ofTPO-R and activating megakaryocytic proliferation of myeloid progenitor cells. Eltrombopag increased platelet counts to 50 × 109/L or higher and reduced bleeding in approximately 60% to 80% of patients in 6-week and 6-month placebo-controlled studies. Although headache and nasopharyngitis are the most commonly reported adverse events (AEs) with eltrombopag in ITP, more serious AEs (SAEs) such as elevated liver enzymes, cataracts, thrombosis, and myelofibrosis have also occurred. All of these events sometimes lead to treatment interruption.

Due to their unique mechanism of action (with limited expectation of efficacy), TPO-RAs are typically considered bridging and maintenance therapies, administered daily or weekly. Because immune thrombocytopenia persists in most chronically ill patients, eltrombopag treatment may be prolonged, not just for months but also for years. Interim results from astudy show that treatment witheltrombopag is safe, well-tolerated and effective in maintaining platelet counts within the ideal range for the majority of 299 patients treated for up to three years.