Eltrombopag

證據等級: L5

預測適應症: 10 個

Eltrombopag: From Immune Thrombocytopenia to HIV Infectious Disease

One-Sentence Summary

Eltrombopag is an oral thrombopoietin receptor (TPO-R) agonist, internationally used to treat thrombocytopenia in immune thrombocytopenic purpura (ITP), hepatitis C-associated thrombocytopenia, and aplastic anaemia. The TxGNN model predicts it may be effective for HIV Infectious Disease — specifically in managing HIV-associated thrombocytopenia — with 5 clinical trials and 10 publications currently supporting this direction.

Quick Overview

Item	Content
Original Indication	Immune thrombocytopenia (ITP) and related thrombocytopaenic conditions (not currently TGA-registered)
Predicted New Indication	HIV Infectious Disease (HIV-associated thrombocytopenia)
TxGNN Prediction Score	99.26%
Evidence Level	L3
Australia Market Status	Not marketed
Number of ARTG Entries	0
Recommended Decision	Proceed with Guardrails

Why is This Prediction Reasonable?

Eltrombopag is a small-molecule, non-peptide TPO-R agonist that binds to the transmembrane domain of the c-Mpl receptor. Unlike endogenous thrombopoietin, it activates the JAK2/STAT signalling pathway to stimulate megakaryocyte proliferation and platelet production without competing with native TPO. Detailed MOA documentation was not available in this evidence pack; however, Eltrombopag’s pharmacology is extensively characterised in international literature, and its clinical efficacy in ITP and aplastic anaemia is well-established.

HIV infection drives thrombocytopenia through two overlapping mechanisms: immune-mediated platelet destruction (autoantibodies and immune complex deposition on platelet surfaces) and direct HIV-associated suppression of megakaryocyte precursors in the bone marrow. These mechanisms are biologically analogous to those seen in primary ITP — Eltrombopag’s established therapeutic setting. By stimulating TPO-R to compensate for reduced platelet production and overcome immune-mediated destruction, Eltrombopag addresses the shared pathophysiological basis of both conditions. Case series and case reports (PMID 25504472, PMID 22992580, PMID 25333665) have confirmed that Eltrombopag successfully raises platelet counts in HIV-positive patients with refractory thrombocytopenia, including one case of severe aplastic anaemia associated with HIV where a trilineage haematological response and immunomodulatory benefit were observed.

A secondary exploratory hypothesis is raised by a 2020 in vitro pharmacological screen (PMID 32977702), which identified Eltrombopag as a potential modulator of HIV-1 proviral transcription. This antiviral mechanism remains entirely unvalidated in clinical settings and should not be considered a primary therapeutic rationale. The clinically meaningful application of Eltrombopag in HIV is therefore best positioned as management of HIV-associated thrombocytopenia, which is mechanistically and clinically analogous to its core ITP indication.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrolment	Key Findings
NCT01636778	Phase 2	Completed	45	SB-497115-GR (Eltrombopag early designation) raised platelet counts in HCV-thrombocytopenic patients with compensated cirrhosis to levels sufficient for antiviral therapy initiation; most directly relevant trial, most likely to have enrolled HIV co-infected subjects
NCT00529568	Phase 3	Completed	759	Largest completed trial — Eltrombopag maintained platelet counts to facilitate Peg-IFN/RBV therapy initiation and minimise dose reductions; SVR measured as primary clinical benefit endpoint (ENABLE series)
NCT00516321	Phase 3	Completed	687	Companion ENABLE trial using Peg-IFN alfa-2a; provides paired indirect evidence for infection-induced immune thrombocytopenia mechanistic analogy
NCT00678587	Phase 3	Terminated	292	Randomised double-blind placebo-controlled trial in chronic liver disease thrombocytopenia undergoing invasive procedures; terminated early — reason not publicly disclosed, requiring investigation before extrapolation
NCT00996216	Phase 3	Completed	27	Open-label rollover safety study assessing long-term tolerability in HCV thrombocytopenia; very small sample size limits efficacy contribution

Literature Evidence

PMID	Year	Type	Journal	Key Findings
25504472	2015	Case Series	J Int Assoc Provid AIDS Care	Eltrombopag and romiplostim effective as salvage therapy for refractory HIV-associated ITP; recommends optimising HAART before initiating TPO-RAs
22185370	2012	Retrospective Series	Platelets	Danish real-world series of 32 patients receiving TPO-RAs; includes off-label secondary ITP use, providing context for HIV-related applications
19932434	2009	Narrative Review	Hematol Oncol Clin N Am	Reviews infectious causes of chronic ITP (HCV, HIV, H. pylori); treating the primary infection often resolves thrombocytopenia; TPO-RAs indicated for refractory cases
19245929	2009	Narrative Review	Semin Hematol	Reviews therapeutic strategies for infection-associated ITP; Eltrombopag discussed as an emerging option for refractory HIV-associated thrombocytopenia
22992580	2012	Case Report	AIDS	Successful eltrombopag use in refractory HIV-related immune reconstitution thrombocytopenia without splenectomy; sustained platelet response achieved
25333665	2014	Case Report	AIDS	First reported eltrombopag treatment for severe aplastic anaemia associated with HIV; trilineage haematological response with immunomodulatory effects (decreased Th1/Th17, increased T-regulatory cell ratio)
24816314	2014	Narrative Review	Intern Med J	Discusses TPO-RA use in ITP of less than 6 months duration across a spectrum of secondary ITP aetiologies including infectious causes
32977702	2020	In Vitro Screen	Viruses	Eltrombopag identified as a potential HIV-1 proviral transcription modulator in an FDA-approved drug library screen; exploratory finding only, no clinical validation to date
28043314	2016	Case Report	J Coll Physicians Surg Pak	HBV-associated peripheral thrombocytopenia and megaloblastic anaemia; contextualises the spectrum of viral infection-induced haematological complications mechanistically relevant to this indication
24128106	2013	Case Report	Farm Hosp	Two cases of eltrombopag in HCV-associated thrombocytopenia; provides bridging evidence from HCV to HIV thrombocytopenic context

Australia Market Information

Eltrombopag is not currently listed on the Australian Register of Therapeutic Goods (ARTG). No ARTG entries were identified for this medicine (data as at 4 April 2026).

Eltrombopag is approved and marketed in several comparable international jurisdictions (e.g., United States as Promacta®, European Union and United Kingdom as Revolade®) for chronic ITP, thrombocytopenia in chronic hepatitis C, and severe aplastic anaemia. Australian prescribers wishing to access this medicine would need to apply through the TGA Special Access Scheme (SAS) or Authorised Prescriber (AP) pathway.

Safety Considerations

Complete TGA-specific safety documentation (approved warnings and contraindications) is not available in this evidence pack.

Please refer to the TGA-approved Product Information (PI) for safety information. In the absence of a current ARTG listing, the international Revolade®/Promacta® Product Information should be reviewed as the primary reference.

For prescriber awareness, the following safety signals are widely documented in international regulatory submissions:

Hepatotoxicity: Serious hepatic adverse events, including cases of hepatic failure, have been reported; liver function tests should be monitored before, during, and following treatment
Thromboembolic events: Platelet count elevation above normal range increases the risk of thromboembolic complications; particular caution is warranted in immunocompromised patients (e.g., advanced AIDS with CD4 count <200/μL) where platelet-mediated thrombosis risk may be compounded
Bone marrow reticulin deposition: Prolonged use may increase reticulin formation; bone marrow examination should be considered in the appropriate clinical context

These points are provided for general awareness only and are not a substitute for formal product information review.

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: The biological rationale is sound — HIV-associated thrombocytopenia shares the same underlying immune dysregulation and bone marrow suppression pathophysiology as ITP and aplastic anaemia, which are Eltrombopag’s internationally approved indications. Supporting case series and case reports confirm clinical benefit in HIV-positive patients, and large-scale Phase 3 RCT data from HCV-related thrombocytopenia provide indirect controlled-trial support for the broader concept of infection-induced immune thrombocytopenia treatment. However, the absence of a dedicated randomised controlled trial in an HIV population, the lack of TGA registration in Australia, and critical gaps in safety documentation prevent a full “Go” decision at this stage.

To proceed, the following is needed:

Retrieve and review the full international Revolade®/Promacta® Product Information to extract complete warnings, contraindications, and monitoring requirements relevant to the Australian clinical context
Obtain detailed mechanism of action documentation from DrugBank API (DG002 data gap) to strengthen the mechanistic justification narrative
Conduct a systematic literature search specifically targeting Phase 2/3 randomised controlled trials in HIV-associated thrombocytopenia populations
Develop a haematological monitoring protocol (full blood count with differential, liver function tests, platelet count target thresholds) tailored to HIV/AIDS patients, accounting for elevated thromboembolic risk at low CD4 counts
Engage the TGA regarding eligibility for the Special Access Scheme Category B (SAS-B) or Authorised Prescriber pathway given the absence of an ARTG listing
Consult with infectious disease and haematology specialists to assess patient selection criteria and determine appropriate monitoring intervals in the Australian HIV-treating context

Disclaimer: This report is for research reference purposes only and does not constitute medical advice. Drug repurposing candidates require clinical validation before therapeutic application. All website content and research outputs should be read in conjunction with appropriate YMYL disclaimers.

Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.