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Avatrombopag tablets

Eisai Inc. · Phase 2 active Small molecule ✓ Verified Jun 2026

Avatrombopag tablets is a Thrombopoietin receptor agonist Small molecule drug developed by Eisai Inc.. It is currently in Phase 2 development for Thrombocytopenia. Also known as: AKR-501, E5501, YM477.

Thrombopoietin receptor agonist

Avatrombopag tablets are a small molecule thrombopoietin receptor agonist, classified as an agonist. They are used to treat conditions such as chemotherapy-induced thrombocytopenia, immune thrombocytopenia, and idiopathic thrombocytopenia purpura.

Likelihood of approval
13.3% vs 15.3% industry baseline
If approved by FDA: likely 2031–2034
Steps remaining: Phase 3 → NDA/BLA submission
Confidence: Medium
Why this estimate
  • Baseline phase 2 → approval rate +15.3pp
    Industry-wide phase 2 drugs reach approval ~15.3% of the time (BIO/Informa 2023 industry benchmark across all therapeutic areas).
  • Oncology Phase 2 attrition -2.0pp
    Oncology drugs have higher Phase 2-to-Phase 3 attrition than average — many fail to show OS benefit in larger studies.
Predicted approval windows by jurisdiction (conditional on FDA approval)
Regulator Country Likely year Lag vs FDA
FDA US 2031–2034
EMA EU 2032–2035 +0.7 yr
MHRA GB 2032–2035 +0.7 yr
Health Canada CA 2032–2036 +0.9 yr
TGA AU 2032–2036 +1.2 yr
PMDA JP 2032–2036 +1.5 yr
NMPA CN 2033–2037 +2.3 yr
MFDS KR 2032–2036 +1.4 yr
CDSCO IN 2032–2037 +1.8 yr
ANVISA BR 2033–2037 +2.3 yr

Hover any row for the lag rationale. Lag estimates are reduced when the drug has FDA Breakthrough or EMA PRIME designation (sponsors file globally in parallel).

Estimate based on the BIO/Informa industry phase transition rates plus per-drug modifiers for therapeutic area, sponsor type, FDA designations, mechanism, and trial design. Per-jurisdiction lags from Tufts CSDD international approval studies. Not investment, clinical or regulatory advice. Methodology: /methodology#likelihood.

At a glance

Generic nameAvatrombopag tablets
Also known asAKR-501, E5501, YM477
SponsorEisai Inc.
Drug classThrombopoietin receptor agonist
TargetThrombopoietin receptor
ModalitySmall molecule
Therapeutic areaOncology
PhasePhase 2

Mechanism of action

Avatrombopag works by binding to and activating the thrombopoietin receptor, stimulating platelet production.

Approved indications

Common side effects

Key clinical trials

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

Frequently asked questions about Avatrombopag tablets

What is Avatrombopag tablets?

Avatrombopag tablets is a Thrombopoietin receptor agonist drug developed by Eisai Inc., indicated for Thrombocytopenia.

How does Avatrombopag tablets work?

Thrombopoietin receptor agonist

What is Avatrombopag tablets used for?

Avatrombopag tablets is indicated for Thrombocytopenia.

Who makes Avatrombopag tablets?

Avatrombopag tablets is developed by Eisai Inc. (see full Eisai Inc. pipeline at /company/eisai).

Is Avatrombopag tablets also known as anything else?

Avatrombopag tablets is also known as AKR-501, E5501, YM477.

What drug class is Avatrombopag tablets in?

Avatrombopag tablets belongs to the Thrombopoietin receptor agonist class. See all Thrombopoietin receptor agonist drugs at /class/thrombopoietin-receptor-agonist.

What development phase is Avatrombopag tablets in?

Avatrombopag tablets is in Phase 2.

What are the side effects of Avatrombopag tablets?

Common side effects of Avatrombopag tablets include Nausea, Headache, Fatigue.

What does Avatrombopag tablets target?

Avatrombopag tablets targets Thrombopoietin receptor and is a Thrombopoietin receptor agonist.

Related

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing