High/Very High Risk Primary Myelofibrosis (Not Transplant Eligible) After First-Line JAK Inhibitor Failure

This protocol addresses patients with high or very high risk primary myelofibrosis who are not eligible for stem cell transplantation and whose first-line JAK inhibitor therapy has not achieved adequate spleen or symptom response — or who could not tolerate it.

Clinical Scenario

Risk category: High or very high risk primary myelofibrosis

Transplant eligibility: Not transplant eligible

First-Line Treatment Failure

Prior therapy: First-line JAK inhibitor (ruxolitinib), dosed to maximise spleen and symptom response.

Escalation triggered by: Failure to achieve at least a 10% reduction in spleen volume, or failure to achieve at least a 50% reduction in symptom burden by approximately 8 weeks — or intolerance to ruxolitinib.

Next-Step Treatment Approach

After first-line failure, the approach involves a second-line JAK inhibitor strategy or alternative novel agents, alongside supportive measures. The choice between options depends on individual patient factors. The complete evidence-based regimen — including agent selection criteria — is in the full protocol.

Instant Access to Structured Evidence-Based Regimens

References

High/very high risk · Not Transplant Eligible
2nd line JAK inhibitor OR novel agents; Supportive measures
Fedratinib is an oral JAK2 inhibitor recommended in the United Kingdom for the treatment of disease-related symptoms or splenomegaly in adults with MF who are resistant to or intolerant of ruxolitinib.
Momelotinib is effective in the treatment of myelofibrosis-related splenomegaly or symptoms.

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