Myelofibrosis is defined in the MONDO ontology as partial or complete replacement of the bone marrow stroma by fibrous tissue. The definition describes it as a primary bone marrow lesion within the chronic myeloproliferative disorders (chronic idiopathic myelofibrosis), as a manifestation of acute myeloid leukemia (acute panmyelosis with myelofibrosis), or as a secondary phenomenon of bone marrow involvement by a metastatic tumor such as metastatic breast carcinoma. Prevalence, onset category and inheritance are not supplied in this packet.

The packet contains no curated phenotype annotations, so symptoms, frequencies and age of onset are unknown in this packet.

No genes, inheritance patterns or molecular mechanism are supplied in this packet. The definition describes fibrous replacement of marrow stroma arising in the contexts of a myeloproliferative disorder, acute myeloid leukemia, or metastatic tumor involvement of the marrow.

No diagnostic methods, GeneReviews diagnosis content or newborn-screening information are supplied in this packet, so diagnostic approaches are unknown here.

The packet's FDA records list two active NDA approvals through CDER: Jakafi (ruxolitinib; approved 2011-11-16) and Vonjo (pacritinib; approved 2022-02-28). Orphan-drug records list Jakafi with the indication treatment of myelofibrosis, and also list momelotinib (Ojjaara) with an approved status, although momelotinib is not among the packet's approved-treatment entries. Numerous other agents, including bomedemstat, imetelstat, luspatercept, navitoclax and selinexor, carry orphan designation for myelofibrosis; designation does not constitute FDA approval, and several designation records are marked withdrawn. No foundational-therapy content is supplied.

Prognosis is not certified in this packet; no natural history information is supplied.

ClinicalTrials.gov lists numerous registered studies. Examples in the packet include NCT07357727, a phase 3 study of pelabresib and ruxolitinib (Novartis; recruiting; 2026-05-27 to 2030-12-27); NCT07447817, a phase 2 study of selinexor and pacritinib (John Mascarenhas; recruiting; 2026-10-23 to 2030-05-24); NCT06661915, a phase 2 study of ASTX727 with or without iadademstat in advanced myeloproliferative neoplasms (National Cancer Institute; recruiting; 2025-08-14 to 2027-12-31); and NCT03441113, extended access of momelotinib (GlaxoSmithKline; active, not recruiting; 2018-05-03 to 2028-12-29). Individuals interested in clinical trials can search ClinicalTrials.gov.