About 3,000 people in the US are diagnosed with myelofibrosis each year, a rare blood cancer in which scar tissue builds up in the bone marrow, causing anemia, an enlarged spleen, fatigue and night sweats. JAK inhibitor pills (ruxolitinib, fedratinib, pacritinib, momelotinib) control the spleen and symptoms but do not change the disease much. Research now focuses on add-on drugs that may slow the disease itself, and on treating the anemia that limits many people.
- 151studies open or running
- 15phase 3 trials
- 490papers published this year
- 35NIH-funded projects
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Now
Nov 2026
Add-on pills shrink spleens furtherHappened 65.9% major spleen shrinkage
Pelabresib plus ruxolitinib: 65.9% had a major spleen shrinkage vs 35.2% with ruxolitinib alone.
65.9%: had a 35%+ spleen shrinkage, vs 35.2% with ruxolitinib alone.
A second add-on, with a survival signalHappened 49.8% major spleen shrinkage
Selinexor plus ruxolitinib: 49.8% vs 28.0% major spleen shrinkage, and an early survival difference.
49.8%: had a 35%+ spleen shrinkage, vs 28.0% with ruxolitinib alone.
A JAK inhibitor that helps anemiaHappened 27% spleen plus transfusion response
Momelotinib improved spleen and freed people from transfusions together in 27% vs 7% with ruxolitinib.
27%: spleen response plus transfusion independence, vs 7% with ruxolitinib.
Options after ruxolitinibHappened 36% major spleen shrinkage
Fedratinib shrank spleens substantially in 36% of people after ruxolitinib vs 6% with other treatment.
36%: had a 35%+ spleen shrinkage, vs 6% with best available therapy.
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6 months
by May 2027
A survival readout for imetelstatPossible
Geron's IMpactMF (327 people), the first myelofibrosis trial designed to show longer survival, expected an interim survival analysis in late 2026; final results due June 2028.
Pacritinib confirmatory trialLikely
PACIFICA (407 people), for people with very low platelets, finishes October 2026.
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12 months
by Nov 2027
An MDM2 blocker added to ruxolitinibPossible
Kartos' POIESIS (600 people) tests navtemadlin added to ruxolitinib from the start; due December 2026.
Longer follow-up of SENTRYPossible
Whether the early survival difference with selinexor holds up will shape its approval case.
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3 years
by late 2029
Pelabresib's second phase 3Possible
Novartis's MANIFEST-3 (460 people) started in 2026; due May 2028.
Interferon for early myelofibrosisPossible
A PharmaEssentia trial (160 people) tests ropeginterferon in early, lower-risk disease, aiming to slow progression; due November 2027.
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5 years
by late 2031
A new anemia drugLong shot
Takeda's ELRISE MF (324 people) tests elritercept for anemia in people on a JAK inhibitor; due December 2029.
The research paths
Add-on drugs to JAK inhibitors
65.9% major spleen shrinkageDetails and 3 trialsHide
BET, XPO1, MDM2 and PIM1 inhibitors added to ruxolitinib to change the course of the disease.
WatchPOIESIS; MANIFEST-3; SENTRY follow-up.
Treating anemia
27% spleen plus transfusion responseDetails and 1 trialsHide
Momelotinib and new red-cell drugs for the anemia that limits treatment.
WatchELRISE MF.
Disease-modifying drugs
Details and 2 trialsHide
Imetelstat and interferon aim to extend survival or slow progression, not just control symptoms.
WatchIMpactMF survival analysis.
More JAK inhibitor options
36% major spleen shrinkageDetails and 1 trialsHide
Four approved JAK inhibitors, matched to blood counts.
WatchPACIFICA.
Borrowed from other cancers
From Myelodysplastic syndromes
Imetelstat
Phase 3
A telomerase blocker approved for lower-risk MDS, tested for survival in myelofibrosis.
From Multiple myeloma
Selinexor
Phase 3
An XPO1 inhibitor approved for myeloma, now added to ruxolitinib.
From Myelodysplastic syndromes
Elritercept
Phase 3
A red-cell maturation drug developed for MDS anemia.
Open to join now
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No prior JAK inhibitor
Navtemadlin plus ruxolitinib
Locations and eligibility → -
No prior JAK inhibitor
Pelabresib plus ruxolitinib
Locations and eligibility → -
Anemia on a JAK inhibitor
Elritercept
Locations and eligibility → -
Myelofibrosis
Nuvisertib
Locations and eligibility →
See every recruiting Myelofibrosis trial →
When the trials finish
Completion dates the trials registered. Results usually follow 3 to 12 months later.
- Heating up
- Maturing
- Early
- Cooling
- Fully enrolled, waiting on results
- Still enrolling
What just happened
SENTRY: selinexor plus ruxolitinib shrinks spleens
J Clin Oncol.
Momelotinib anemia benefit linked to survival
SIMPLIFY-1 analysis.
MANIFEST-2: pelabresib doubles spleen responses
Nature Medicine.
Standard treatment today
- Lower risk, few symptomsWatch; interferon or a JAK inhibitor if symptoms develop.
- Higher risk or symptomaticJAK inhibitor: ruxolitinib or fedratinib; momelotinib if anemic; pacritinib if platelets are very low.
- After ruxolitinibSwitch JAK inhibitor; clinical trials of add-on drugs.
- Fit, higher riskAllogeneic stem-cell transplant, the only cure.
How to read this page, and sourcesHow to read this page, and sources
- Spleen shrinkage and symptom scores are the usual trial goals; few trials yet show longer survival.
- Forecasts are editorial judgments by Find a Trial, not predictions from sponsors or regulators.
See Myelofibrosis trials recruiting now →