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Protein / target

Thrombopoietin receptor

Encoded byMPLP40238Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
7
Approved medicines
Open Targets target-level
View by indication →
6
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

Thrombopoietin receptor

Strongest disease association

Primary myelofibrosis

Via encoding gene MPL · Genetic evidence · score 0.87

Therapeutic position

Established drug target

Small molecules

Derived from structured UniProt, Open Targets and literature data on this page.

Protein profile

UniProt 2026_02

Canonical identity and biological annotation from UniProt.

Function overview

Receptor for thrombopoietin that regulates hematopoietic stem cell renewal, megakaryocyte differentiation, and platelet formation.

View complete UniProt function annotation

Receptor for thrombopoietin that regulates hematopoietic stem cell renewal, megakaryocyte differentiation, and platelet formation. Upon activation by THPO, induces rapid tyrosine phosphorylation and activation of JAK2, providing docking sites for many signaling proteins such as STAT5, SHIP/INPP5D, GRB2, SOS1 and PI3K (PubMed:15899890, PubMed:37633268). In turn, These signaling cascades lead to the proliferation, survival, and differentiation of megakaryocytes, ultimately leading to increased platelet production

Subcellular location

Cell membraneGolgi apparatusCell surface
Domains and Gene Ontology detail (18)

Domains & features

Fibronectin type-III 1Fibronectin type-III 2

Gene Ontology

  • Ccell surface
  • Cexternal side of plasma membrane
  • CGolgi apparatus
  • Cneuronal cell body
  • Cplasma membrane
  • Fthrombopoietin receptor activity
  • Pbasophil homeostasis
  • Pcellular response to hypoxia
  • Peosinophil homeostasis
  • Pmonocyte homeostasis
  • Pneutrophil homeostasis
  • Pplatelet formation

635 aa · 71 kDa · 2 isoforms

Biological roles

What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.

HaemostasisUniProt · GO
View supporting evidence

Haemostasis

  • ·Receptor for thrombopoietin that regulates hematopoietic stem cell renewal, megakaryocyt…
  • ·platelet formation
  • ·positive regulation of platelet formation

Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.

Approved medicines with mapped indications

1 medicine · 2 areas

Approved therapies targeting this protein, grouped by what they are approved to treat — the disease-first view of the medicines below. Relationships come from the canonical approved-indication graph (ChEMBL phase-4), the same source as the drug cards.

Hemorrhage1 medicine
Thrombocytopenia1 medicine

7 medicines meet Open Targets' target-level approved-medicine definition; the 1 shown here are those on this page with a canonical approved disease indication in the graph. Approved indications from ChEMBL (phase-4), via the canonical drug→disease graph.

Drugs targeting this protein

1

How approved and investigational drugs engage this protein — mechanism and action type, direct vs complex targeting, and how broadly each acts across other targets. A drug-first view (the section above groups the approved ones disease-first); direct binders with few recorded targets are listed first.

lusutrombopag
Narrow target profileApprovedAgonist

Thrombopoietin receptor agonist

Indicated for Hemorrhage, Thrombocytopenia

Direct interaction with this protein · Only this protein recorded as a target

ChEMBL mechanism, action type, target identity and approved indications. Open Targets clinical status.

Translational evidence

Open Targets 26

Why this target matters therapeutically, strongest evidence first. Disease associations are gene-level (via the gene that encodes this protein) and open into the full confidence synthesis; the development universe, tractability and safety annotations are target-level, from Open Targets.

Strongest disease associations · via encoding gene MPL

Gene-level evidence surfaced through the gene MPLthat encodes this protein — not a direct protein–disease relationship. Ranked by Forefront's causal-directness weighting, so genetically- and clinically-evidenced diseases lead over ones that merely share the literature.

Primary myelofibrosis
0.91Well supported

Genetic evidence dominant · Open Targets 0.71

Purpura, Thrombocytopenic, Idiopathic
0.84Well supported

Clinical evidence dominant · Open Targets 0.63

Anemia, Aplastic
0.74Moderately supported

Clinical evidence dominant · Open Targets 0.54

Hepatitis C, Chronic
0.62Moderately supported

Clinical evidence dominant · Open Targets 0.50

View evidence synthesis (4)
Primary myelofibrosisWell supported
0.91
agreement 0.791.00
Genetic74%Animal model17%Literature9%Genetic literaturedup

Open Targets aggregate 0.71 · 3 independent evidence families · 1 not counted as duplicate

Purpura, Thrombocytopenic, IdiopathicWell supported
0.84
agreement 0.710.97
Clinical63%Animal model27%Literature10%

Open Targets aggregate 0.63 · 3 independent evidence families

Anemia, AplasticModerately supported
0.74
agreement 0.620.87
Clinical68%Animal model30%Literature2%

Open Targets aggregate 0.54 · 3 independent evidence families

Hepatitis C, ChronicModerately supported
0.62
agreement 0.470.78
Clinical99%Literature1%

Open Targets aggregate 0.50 · 2 independent evidence families

The evidence agreement range shows how closely the independent evidence families agree — it is not a statistical confidence interval, and nothing here is fitted to outcome data. Derived from Open Targets evidence types under Forefront weighting; the per-type scores above show the calculation.

Show all associations
Primary myelofibrosis0.71
Purpura, Thrombocytopenic, Idiopathic0.63
Anemia, Aplastic0.54
Hepatitis C, Chronic0.50

Drug development

9 compounds recorded · 7 approved · 2 in clinical development

Open Targets' development universe — every compound recorded against the target at any stage, not all approved medicines. Distinct from the 1 drug that targets this protein in Forefront's canonical graph (1 with a mapped approved indication, shown above): these count different sets and are not a subset relation.

View all recorded compounds (9)
RAFUTROMBOPAGPhase 3
ELTROMBOPAGApproval
ELTROMBOPAG CHOLINEApproval
AVATROMBOPAGApproval
AVATROMBOPAG MALEATEApproval
ROMIPLOSTIMApproval
ELTROMBOPAG OLAMINEApproval
HETROMBOPAG OLAMINEPhase 3
LUSUTROMBOPAGApproval

Open Targets known-drugs universe. Drug name and highest clinical stage only — the disease relationship is NOT read from this slice (it carries trial-context noise); approved indications come from the canonical graph above.

Tractability

Small moleculesStrong

Approved Drug and High-Quality Ligand support this modality.

AntibodiesEmerging

Feasibility evidence (uniprot loc high conf and go cc high conf) — no clinical-stage drug of this modality recorded.

Protein degradersEmerging

Feasibility evidence (uniprot ubiquitination and database ubiquitination) — no clinical-stage drug of this modality recorded.

Other modalitiesStrong

Approved Drug support this modality.

View underlying tractability evidence (11)
SM · Approved DrugSM · High-Quality LigandSM · Druggable FamilyAB · UniProt loc high confAB · GO CC high confAB · UniProt SigP or TMHMMAB · Human Protein Atlas locPR · UniProt UbiquitinationPR · Database UbiquitinationPR · Small Molecule BinderOC · Approved Drug

Raw Open Targets tractability assessment buckets, by modality.

Clinical trials

6

Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein. Ranked by active status, then clinical phase and recency, and spread across the targeting drugs.

ClinicalTrials.gov via the drug-target graph.

What's happening now

1

Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for a drug that targets this protein, plus publications where such a drug is a genuine subject. Every item is reached indirectly through the drug, not the protein itself; incidental mentions (a paper that merely measures a drug) and press items are excluded.

  1. Withdrawn from market2026-04-14

    Market withdrawal: Mulpleo (previously Lusutrombopag Shionogi) (EMA)

    ema · market · ema · via lusutrombopag

Objective event titles are shown unmodified; the event kind and significance line are derived from structured fields. Forefront AttentionEvent stream aggregating Europe PMC Regulatory filings ClinicalTrials.gov.