ASH Issues New Recommendations to Improve Myelofibrosis Care

(WASHINGTON – Oct. 14, 2026) – The American Society of Hematology (ASH) released guidelines on the management of myelofibrosis, a rare and life-threatening blood cancer. ASH’s new guidelines recommend expanded molecular testing, early transplant referral, appropriate use of JAK inhibitors, and aspirin therapy in select patients.

What is Myelofibrosis?

Myelofibrosis is a type of myeloproliferative neoplasm, a group of chronic blood cancers in which the bone marrow overproduces different types of blood cells. In myelofibrosis, the bone marrow – or spongy inside of the bone that produces blood cells – develops scar tissue, impacting its ability to make enough healthy blood cells. Myelofibrosis affects only a small number of people, with estimates that up to six per 100,000 people are living with the disease.

Individuals with myelofibrosis are at risk of developing acute myeloid leukemia and other serious, disease-related complications, including enlargement of the spleen (an organ that helps fight infection and filter blood) and development of blood clots.

Myelofibrosis can often be managed over time with medications, including JAK inhibitors, which can help reduce spleen enlargement and ease other symptoms of the disease. Currently, the only potentially curative treatment is allogeneic stem cell transplant, in which a patient’s faulty cells are replaced with healthy, blood-forming stem cells from a donor.

New ASH Guidelines Aim to Improve Outcomes for Rare Disease

ASH’s evidence-based guidelines help address decision-making gaps in the care of myelofibrosis. Because myelofibrosis is rare and progresses, approaches to treatment can vary substantially among clinicians.

The guidelines consist of ten recommendations aimed at improving outcomes for individuals living with myelofibrosis, from testing to transplant management. The guidelines were published in the Society’s peer-reviewed journal, Blood Advances, and developed through a rigorous review process by a multidisciplinary expert panel that included myelofibrosis and transplant specialists, methodology experts, and a patient and caregiver with lived experience.

The recommendations include guidance on:

• Extended molecular testing at diagnosis to help identify high-risk mutations and guide care
• Early transplant consultation for higher-risk individuals receiving and responding to JAK inhibitors
• Strategies for managing anemia related to myelofibrosis or JAK inhibitor therapy
• Use of JAK inhibitors for lower-risk individuals with disease-related symptoms and avoidance of JAK inhibitors in higher-risk individuals without disease-related symptoms
• Low-dose aspirin for patients with the JAK2 V617F mutation

“These recommendations address questions that routinely come up for clinicians and patients managing myelofibrosis, and our hope is that they will enable hematologists to more confidently deliver better care to their patients,” said guideline panel chair Brady Stein, MD, professor of medicine at Northwestern University’s Feinberg School of Medicine. “That said, important gaps in evidence remain, and we hope the questions we asked can help set a future research agenda to further improve care for patients with this disease.”

The guidance identifies several areas in which more research is needed to continue improving outcomes for patients, including enhancing prediction of which patients will benefit from specific treatments, establishment of better approaches to myelofibrosis-related anemia, and clarification of timing for transplant.

Additional guideline resources, including snapshots, visual summaries, and teaching slides, can be accessed at hematology.org/myelofibrosis-guidelines.

What Patients Should Know

The guidance clinicians use for treating myelofibrosis has changed. The new ASH guidelines emphasize individualized care for myelofibrosis based on a patient’s symptoms, spleen enlargement, anemia, genetic testing results, transplant eligibility, and personal preferences.

Patients may want to ask their care team whether extended molecular testing is appropriate for them, whether a JAK inhibitor may help with symptoms or spleen enlargement, how anemia should be managed, and whether they should be referred for a stem cell transplant consultation. For patients with a specific genetic mutation called JAK2 V617F, the guidelines also address the use of low-dose aspirin to help prevent blood clots.