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Disease

Primary myelofibrosis

Late-stage therapeutic development
Also known as AMM, Agnogenic myeloid metaplasia, CIMF, aleukemic myelosis+13 more

AMM, Agnogenic myeloid metaplasia, CIMF, aleukemic myelosis, bone marrow fibrosis, chronic idiopathic myelofibrosis, idiopathic bone marrow fibrosis, idiopathic myelofibrosis, megakaryocytic myelosclerosis, myelofibrosis with myeloid metaplasia, somatic, myelofibrosis, somatic, myelosclerosis, myelosclerosis with myeloid metaplasia, osteomyelofibrosis, myelofibrosis, myeloid metaplasia, myelofibrosis with myeloid metaplasia.

18
Clinical trials
12
Associated genes
4
Related proteins
Current focus
Calreticulin biologyTherapeutic developmentThrombopoietin biology
Latest activity
beta

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

Generic medicine authorisation: Ruxolitinib Viatris (EMA)

Regulatory2026-09-18EMA

A Randomized, Double-Blind, Placebo-Controlled Multicenter Phase III Study to Assess Efficacy and Safety of Ropeginterferon Alfa-2b (P1101) in Adult Patients With Pre-fibrotic/Early Primary Myelofibrosis (PMF) or Overt PMF at Low or Intermediate-1 Risk According to DIPSS Plus (HOPE-PMF): The Core Study and Its Extension Study

Clinical trial2026-07-22Status changed to Active, not recruiting · ClinicalTrials.gov

A Phase 3, Double-blind, Randomized Study to Compare the Efficacy and Safety of Luspatercept (ACE-536) Versus Placebo in Subjects With Myeloproliferative Neoplasm-Associated Myelofibrosis on Concomitant JAK Inhibitor Therapy and Who Require Red Blood Cell Transfusions

Clinical trial2026-07-16Results posted · ClinicalTrials.gov

What's happening now

An analyst briefing on current research, clinical, regulatory and industry activity surrounding this disease.

Executive briefingUpdating summary…Momentum: Moderate
Key developments
  • 3 clinical trials expected to report results, the earliest in Q4 2026.
Upcoming Milestones
Major developments
Upcoming trial readoutHigh impact
A Randomized, Double-Blind, Placebo-Controlled Multicenter Phase III Study to Assess Efficacy and Safety of Ropeginterferon Alfa-2b (P1101) in Adult Patients With Pre-fibrotic/Early Primary Myelofibrosis (PMF) or Overt PMF at Low or Intermediate-1 Risk According to DIPSS Plus (HOPE-PMF): The Core Study and Its Extension Study
Results expected Q4 20272026-08-13
Major trial resultsHigh impact
A Phase II Study of Decitabine in Myelofibrosis
Results posted2026-08-26
CHMP positive opinion (EU decision pending)Important
CHMP positive opinion — Ruxolitinib
Treatment of myelofibrosis (MF) in adults, treatment of polycythaemia vera (PV) in adults and treatment of Graft versus host disease (GvHD) in adults and children2026-09-18
Clinical Milestones6View
Results posted 1
Results expected 3
Recently completed 2
Regulatory Updates2View
Activity timeline8

Therapeutic landscape

Therapies with a regulatory footing for this condition, alongside the wider set of agents co-studied with it in the literature.

Approved & established therapies
Ruxolitinibapproved

Generic approval — Myelofibrosis (MF)  Ruxolitinib Viatris is indicated for the treatment of disease-… (2026)

Momelotinib dihydrochloride monohydrateapproved

Original application approval — Omjjara is indicated for the treatment of disease-related splenomegaly or symptoms in adu… (2024)

Clinical trials

12 sponsors · 0 new · 0 completed in the last 12 months (net +0)

The current development programme across all trial phases.

Clinical programme
18
All trials
6
Active
8
Late-stage
6
Completed
Late-stage studies

A Randomized, Double-Blind, Placebo-Controlled Multicenter Phase III Study to Assess Efficacy and Safety of Ropeginterferon Alfa-2b (P1101) in Adult Patients With Pre-fibrotic/Early Primary Myelofibrosis (PMF) or Overt PMF at Low or Intermediate-1 Risk According to DIPSS Plus (HOPE-PMF): The Core Study and Its Extension Study

Phase 3 · Active, not recruiting · PharmaEssentia

A Randomized, Controlled Phase 3 Study of Pacritinib Versus Physician's Choice in Patients With Primary Myelofibrosis, Post Polycythemia Vera Myelofibrosis, or Post-Essential Thrombocythemia Myelofibrosis With Severe Thrombocytopenia (Platelet Count <50,000/μL)(PACIFICA)

Phase 3 · Active, not recruiting · Swedish Orphan Biovitrum

A Phase 3, Multicenter, Open-label, Randomized Study to Evaluate the Efficacy and Safety of Fedratinib Compared to Best Available Therapy (BAT) in Subjects With DIPSS (Dynamic International Prognostic Scoring System)-Intermediate or High-risk Primary Myelofibrosis (PMF), Post-polycythemia Vera Myelofibrosis (Post-PV MF), or Post-essential Thrombocythemia Myelofibrosis (Post-ET MF) and Previously Treated With Ruxolitinib

Phase 3 · Completed · Celgene

A Randomized, Double-blind, Phase 3 Study to Evaluate the Activity of Momelotinib (MMB) Versus Danazol (DAN) in Symptomatic, Anemic Subjects With Primary Myelofibrosis (PMF), Post-polycythemia Vera (PV) Myelofibrosis, or Post-essential Thrombocythemia (ET) Myelofibrosis Who Were Previously Treated With JAK Inhibitor Therapy

Phase 3 · Completed · Sierra Oncology LLC - a GSK company

A Phase 3, Randomized Study To Evaluate the Efficacy of Momelotinib Versus Best Available Therapy in Anemic or Thrombocytopenic Subjects With Primary Myelofibrosis, Post-polycythemia Vera Myelofibrosis, or Post-essential Thrombocythemia Myelofibrosis Who Were Treated With Ruxolitinib

Phase 3 · Completed · Sierra Oncology LLC - a GSK company

A Phase-3, Multi-Center, Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study to Compare Efficacy and Safety of Pomalidomide in Subjects With Myeloproliferative Neoplasm-Associated Myelofibrosis and Red Blood Cell-Transfusion-Dependence

Phase 3 · Completed · Celgene
Recently completed

A Phase 3, Multicenter, Open-label, Randomized Study to Evaluate the Efficacy and Safety of Fedratinib Compared to Best Available Therapy (BAT) in Subjects With DIPSS (Dynamic International Prognostic Scoring System)-Intermediate or High-risk Primary Myelofibrosis (PMF), Post-polycythemia Vera Myelofibrosis (Post-PV MF), or Post-essential Thrombocythemia Myelofibrosis (Post-ET MF) and Previously Treated With Ruxolitinib

Phase 3 · Completed · Celgene

Open Label Phase 2 Single Agent Study of LCL-161 in Patients With Primary Myelofibrosis (PMF), Post-Polycythemia Vera Myelofibrosis (Post-PV MF), or Post-Essential Thrombocytosis Myelofibrosis (Post-ET MF)

Phase 2 · Completed · M.D. Anderson Cancer Center

A Randomized, Double-blind, Phase 3 Study to Evaluate the Activity of Momelotinib (MMB) Versus Danazol (DAN) in Symptomatic, Anemic Subjects With Primary Myelofibrosis (PMF), Post-polycythemia Vera (PV) Myelofibrosis, or Post-essential Thrombocythemia (ET) Myelofibrosis Who Were Previously Treated With JAK Inhibitor Therapy

Phase 3 · Completed · Sierra Oncology LLC - a GSK company

A Phase 3, Randomized Study To Evaluate the Efficacy of Momelotinib Versus Best Available Therapy in Anemic or Thrombocytopenic Subjects With Primary Myelofibrosis, Post-polycythemia Vera Myelofibrosis, or Post-essential Thrombocythemia Myelofibrosis Who Were Treated With Ruxolitinib

Phase 3 · Completed · Sierra Oncology LLC - a GSK company

A Phase 2 Pilot Trial of Ruxolitinib Combined With Danazol for Patients With Primary Myelofibrosis (MF), Post Essential Thrombocythemia-Myelofibrosis (Post ET) and Post Polycythemia Vera Myelofibrosis (PV MF) Suffering From Anemia

Phase 2 · Completed · Mayo Clinic

A Phase-3, Multi-Center, Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study to Compare Efficacy and Safety of Pomalidomide in Subjects With Myeloproliferative Neoplasm-Associated Myelofibrosis and Red Blood Cell-Transfusion-Dependence

Phase 3 · Completed · Celgene

Regulatory timeline

Drug regulatory events matched to this condition by indication — EMA.

Product approvals and authorisations
2026emaGeneric approval — Ruxolitinib· Myelofibrosis (MF)&nbsp; Ruxolitinib Viatris is indicated for the treatment of disease-related splenomegaly or symptoms in adult patients with primary myelofibrosis (also known as chronic idiopathic myelofibrosis), post polycythaemia vera myelofibrosis or post essential thrombocythaemia myelofibrosis.&nbsp; Polycythaemia vera (PV)&nbsp; Ruxolitinib Viatris is indicated for the treatment of adult patients with polycythaemia vera who are resistant to or intolerant of hydroxyurea.&nbsp; Graft versus host disease (GvHD)&nbsp;&nbsp; Acute GvHD&nbsp;Ruxolitinib Viatris is indicated for the treatment of adults and paediatric patients aged 28 days and older with acute graft versus host disease who have inadequate response to corticosteroids or other systemic therapies (see section 5.1). Chronic GvHD&nbsp;Ruxolitinib Viatris is indicated for the treatment of adults and paediatric patients aged 6 months and older with chronic graft versus host disease who have inadequate response to corticosteroids or other systemic therapies (see section 5.1). source ↗
2024emaOriginal application approval — Momelotinib dihydrochloride monohydrate· Omjjara is indicated for the treatment of disease-related splenomegaly or symptoms in adult patients with moderate to severe anaemia who have primary myelofibrosis, post polycythaemia vera myelofibrosis or post essential thrombocythaemia myelofibrosis and who are Janus Kinase (JAK) inhibitor naïve or have been treated with ruxolitinib. source ↗
2012emaOriginal application approval — Ruxolitinib· Myelofibrosis (MF)Jakavi is indicated for the treatment of disease related splenomegaly or symptoms in adult patients with primary myelofibrosis (also known as chronic idiopathic myelofibrosis), post polycythaemia vera myelofibrosis or post essential thrombocythaemia myelofibrosis.Polycythaemia vera (PV)Jakavi is indicated for the treatment of adult patients with polycythaemia vera who are resistant to or intolerant of hydroxyurea.Graft versus host disease (GvHD)Acute GvHDJakavi is indicated for the treatment of adults and paediatric patients aged 28 days and older with acute graft versus host disease who have inadequate response to corticosteroids or other systemic therapies (see section 5.1).Chronic GvHDJakavi is indicated for the treatment of adults and paediatric patients aged 6 months and older with chronic graft versus host disease who have inadequate response to corticosteroids or other systemic therapies (see section 5.1). Myelofibrosis (MF)Jakavi is indicated for the treatment of disease related splenomegaly or symptoms in adult patients with primary myelofibrosis (also known as chronic idiopathic myelofibrosis), post polycythaemia vera myelofibrosis or post essential thrombocythaemia myelofibrosis.Polycythaemia vera (PV)Jakavi is indicated for the treatment of adult patients with polycythaemia vera who are resistant to or intolerant of hydroxyurea.Graft versus host disease (GvHD)Acute GvHDJakavi is indicated for the treatment of adults and paediatric patients aged 28 days and older with acute graft versus host disease who have inadequate response to corticosteroids or other systemic therapies (see section 5.1).Chronic GvHDJakavi is indicated for the treatment of adults and paediatric patients aged 6 months and older with chronic graft versus host disease who have inadequate response to corticosteroids or other systemic therapies (see section 5.1). source ↗
Other regulatory activity
2026emaCHMP positive opinion — Ruxolitinib· Treatment of myelofibrosis (MF) in adults, treatment of polycythaemia vera (PV) in adults and treatment of Graft versus host disease (GvHD) in adults and children source ↗
2026emaCHMP positive opinion — Ruxolitinib· Treatment of myelofibrosis (MF), polycythaemia vera (PV) and Graft versus host disease (GvHD). source ↗

European Medicines Agency (CC BY 4.0). Events are matched to this condition by drug indication text — approvals/updates for drugs indicated for it, not disease-specific acts.

Associated genes

12 matches

Genes associated with this disease in the canonical knowledge graph (Open Targets evidence). Number shows the association score.

JAK20.75MPL0.71FLT30.57CALR0.56FBXW120.06MID20.05CIAO2B0.05FAM124A0.05AIF1L0.05FAM81A0.05ABTB10.04RPEL10.04

Disease biology

4 matches

Proteins whose encoding gene is associated with this disease, reached through the canonical gene→disease graph. Number shows the gene's association score.

Tyrosine-protein kinase JAK2via JAK20.75Thrombopoietin receptorvia MPL0.71Receptor-type tyrosine-protein kinase FLT3via FLT30.57Calreticulinvia CALR0.56

Reference

Authoritative identity, definition & identifiers.

Defined in MeSH

A de novo myeloproliferation arising from an abnormal stem cell. It is characterized by the replacement of bone marrow by fibrous tissue, a process that is mediated by CYTOKINES arising from the abnormal clone.

Synonyms

AMM, Agnogenic myeloid metaplasia, CIMF, aleukemic myelosis, bone marrow fibrosis, chronic idiopathic myelofibrosis, idiopathic bone marrow fibrosis, idiopathic myelofibrosis, megakaryocytic myelosclerosis, myelofibrosis with myeloid metaplasia, somatic, myelofibrosis, somatic, myelosclerosis, myelosclerosis with myeloid metaplasia, osteomyelofibrosis, myelofibrosis, myeloid metaplasia, myelofibrosis with myeloid metaplasia

References & data sources
  • Disease identity & definition — NLM Medical Subject Headings (MeSH), public domain
  • Clinical trials — ClinicalTrials.gov (U.S. National Library of Medicine)
  • Related entities are derived from literature co-mention (studied together) — associative, not causal.