From the Guidelines
The FDA-approved drugs used to stimulate megakaryocytes to produce platelets are thrombopoietin receptor agonists (TPO-RAs), primarily eltrombopag and romiplostim, as supported by the most recent and highest quality study 1. These medications are primarily used to treat chronic immune thrombocytopenia (ITP) and thrombocytopenia associated with certain other conditions.
- Eltrombopag (brand name Promacta) is typically taken orally, with a starting dose of 50 mg once daily, which can be adjusted based on platelet response.
- Romiplostim (brand name Nplate) is administered as a weekly subcutaneous injection, with the dose calculated based on the patient's weight and platelet count. They work by binding to and activating the thrombopoietin receptor on megakaryocytes, stimulating the production and maturation of platelets. Key points to consider when using these medications include:
- Treatment duration varies depending on the underlying condition and individual response.
- Regular monitoring of platelet counts is essential to adjust dosing and prevent excessive platelet production.
- These medications should be prescribed and monitored by a hematologist or other specialist familiar with their use, as indicated by studies 1. The use of TPO-RAs has been shown to be highly effective, with initial responses observed already after 1–2 weeks of treatment, while significantly reducing bleeding events and emergency hospitalizations, as reported in the literature 1.
From the FDA Drug Label
Eltrombopag is a TPO-receptor agonist that interacts with the transmembrane domain of the human TPO-receptor (also known as cMpl) and initiates signaling cascades that induce proliferation and differentiation of megakaryocytes leading to increased platelet production. Romiplostim is a thrombopoietin receptor agonist (TPO-RA). Romiplostim, a member of the TPO mimetic class, is an Fc-peptide fusion protein (peptibody). Nplate increases platelet production through binding and activation of the TPO receptor, a mechanism analogous to endogenous TPO.
The FDA-approved drugs used to stimulate megakaryocytes to produce platelets are:
- Romiplostim (Nplate), a thrombopoietin receptor agonist (TPO-RA) 2
- Eltrombopag, a TPO-receptor agonist 3
From the Research
FDA Approved Drugs for Stimulating Megakaryocytes
The following FDA approved drugs are used to stimulate megakaryocytes to produce platelets:
- Romiplostim
- Eltrombopag
- Avatrombopag
- Lusutrombopag
Mechanism of Action
These drugs, known as thrombopoietin receptor agonists (TPO-RAs), work by stimulating the thrombopoietin receptor on megakaryocytes, leading to an increase in platelet production 4, 5, 6, 7, 8.
Conditions Treated
TPO-RAs are used to treat various conditions, including:
- Chronic immune thrombocytopenia (ITP)
- Thrombocytopenia in adult patients with chronic liver disease
- Severe aplastic anemia
- Thrombocytopenia associated with interferon-based therapy for hepatitis C 4, 5, 6, 7.
Key Findings
Studies have shown that these drugs are effective in increasing platelet counts and reducing the incidence of bleeding in patients with treatment-refractory chronic ITP 4, 5, 6.