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Drug

Imetelstat

Approved · EMA
ClassTelomerase reverse transcriptase inhibitorEmerging researchLate-stage development

Also known as Rytelo.

RxNorm2685236ChEMBLCHEMBL2107856ATCL01XX80UNIIF60NE4XB53
1
Research papers
4
Active clinical trials
Telomerase reverse transcriptase
Primary target
1
Regulatory events
Latest activity
beta

Recent clinical, regulatory, research and industry developments relating to this drug.

A Randomized Open-Label, Phase 3 Study to Evaluate Imetelstat (GRN163L) Versus Best Available Therapy (BAT) in Patients With Intermediate-2 or High-risk Myelofibrosis (MF) Relapsed / Refractory (R/R) to Janus Kinase (JAK) Inhibitor

Clinical trial2026-07-08Results expected Q2 2028 · ClinicalTrials.gov

Phase 2 Study Of Imetelstat for Patient With Myelodysplastic/Myeloproliferative Neoplasms

Clinical trial2026-04-24Results expected Q2 2027 · ClinicalTrials.gov

IMetelstat and Azacitidine With or Without Venetoclax GIveN in rElapsed Acute Myeloid Leukemia (IMAGINE Trial)

Clinical trial2026-04-22Results expected Q2 2030 · ClinicalTrials.gov

A Phase 1 Study of GRN163L (Imetelstat) in Combination With Fludarabine and Cytarabine for Patients With Acute Myeloid Leukemia That is in Second or Greater Relapse or That is Refractory to Relapse Therapy; Myelodysplastic Syndrome or Juvenile Myelomonocytic Leukemia in First or Greater Relapse or is Refractory to Relapse Therapy

Clinical trial2026-04-20Results expected Q1 2028 · ClinicalTrials.gov

Approval: Rytelo (EMA)

Regulatory2025-03-07EMA

Imetelstat-mediated alterations in fatty acid metabolism to induce ferroptosis as a therapeutic strategy for acute myeloid leukemia.

Research2023-10-30Nature cancer

A Pilot Open-Label Study of the Efficacy and Safety of Imetelstat (GRN163L) in Myelofibrosis and Other Myeloid Malignancies

Clinical trial2021-09-21Results posted · ClinicalTrials.gov

A Phase II Trial to Evaluate the Activity of Imetelstat (GRN163L) in Patients With Essential Thrombocythemia or Polycythemia Vera Who Require Cytoreduction and Have Failed or Are Intolerant to Previous Therapy, or Who Refuse Standard Therapy

Clinical trial2015-04-01Completed · ClinicalTrials.gov

A Pilot Study of Imetelstat Given Intravenously on Day 1 and 8 of a 21 Day Schedule Alone and With Standard 13-Cis-Retinoic Acid in Children With Recurrent and/or Refractory Neuroblastoma

Clinical trial2014-01-16Withdrawn · ClinicalTrials.gov

A Randomized Phase II Study of Imetelstat as Maintenance Therapy After Initial Induction Chemotherapy for Advance Non-small Cell Lung Cancer(NSCLC)

Clinical trial2013-09-01Completed · ClinicalTrials.gov

A Phase 1 Study of Imetelstat, a Telomerase Inhibitor, in Children With Refractory or Recurrent Solid Tumors and Lymphomas

Clinical trial2012-10-01Withdrawn · ClinicalTrials.gov

Profile

Identifiers & mechanism

Canonical identifiers, marketed brand names and mechanism, resolved across RxNorm, ChEMBL and ATC.

Canonical name
Imetelstat
Aliases & brands
Rytelo
RxNorm CUI
2685236
ChEMBL ID
CHEMBL2107856
ATC codes
L01XX80
UNII
F60NE4XB53
Primary mechanism
Telomerase reverse transcriptase inhibitor
Regulatory jurisdictions
ema

Pharmacology & targets

1 target

Known molecular targets and mechanisms supported by curated pharmacology databases.

Telomerase reverse transcriptase
TERT · O14746
INHIBITORTelomerase reverse transcriptase inhibitor

Regulatory timeline

1 event

The complete regulatory record, grouped by authority — approvals, safety advisories and label changes. Each authority shows its most recent events; expand one to read its full history.

Earliest approval
2025-03-07
Latest approval
2025-03-07
Authorities
EMA
Total events
1
emaEuropean Medicines Agency· 1 event
2025-03-07Approval
Approval: Rytelo (EMA)
Indication: Treatment of transfusion-dependent anaemia in adults with low- to intermediate-1 risk myelodysplastic syndromes (MDS) who have failed to respond or have lost response to or are… Show full indication

Treatment of transfusion-dependent anaemia in adults with low- to intermediate-1 risk myelodysplastic syndromes (MDS) who have failed to respond or have lost response to or are ineligible for erythropoiesis-stimulating agents (ESA).

Evidence ↗

Contains information from the European Medicines Agency (European Medicines Agency), © EMA, reused under CC BY 4.0.

Clinical trials

9 trials

The current development programme across all trial phases — status mix, phase distribution and the late-stage studies shaping the evidence base.

Development programme
CLINICALTRIALS.GOV · LIVE REGISTRY
9
registered trials across all phases
LATEST COMPLETION 2018
4
Active studies
3
Recruiting
1
Late-stage (III+)
3
Completed
2
Discontinued
PHASE DISTRIBUTIONn = 9
Phase 14Phase 24Phase 31

Late-stage studies

Phase III+ trials still open or recently active — where late-stage evidence is being generated.

A Randomized Open-Label, Phase 3 Study to Evaluate Imetelstat (GRN163L) Versus Best Available Therapy (BAT) in Patients With Intermediate-2 or High-risk Myelofibrosis (MF) Relapsed / Refractory (R/R) to Janus Kinase (JAK) Inhibitor

Active, not recruitingPH IIIGeron Corporationn=3272028

Research activity

1 papers

Key research shaping understanding of this drug, combining the latest publications with the most influential evidence.

Major research themes4
Ferroptosis1Leukemia, Myeloid, Acute1Oligonucleotides1Telomerase1
Journals, researchers & institutions
Top journals
  • Nature cancer1
Leading researchers
  • Abdel-Wahab O1
  • Bray LJ1
  • Bruedigam C1
  • Bullinger L1
  • Cheng G1
  • Cooper L1
  • Haldar R1
  • Hartel G1
Leading institutions
free-text, unnormalised
  • Charité University Medicine Berlin1
  • Children's Medical Research Institute1
  • Leibniz Institute on Aging1
  • Memorial Sloan Kettering Cancer Center1
  • QIMR Berghofer Medical Research Institute1
  • Royal Brisbane and Women's Hospital1
References & data sources
  • RxNorm (U.S. National Library of Medicine) — drug identity
  • ChEMBL (EMBL-EBI) & UniProt — pharmacology and targets
  • Europe PMC — research literature
  • ClinicalTrials.gov — clinical trials
  • Regulatory event sources are credited in the Regulatory Timeline above.