Treatment of Primary Myelofibrosis When Ruxolitinib or Fedratinib Does Not Achieve the Target Response

Patient Scenario

This pathway addresses non-low-risk primary myelofibrosis presenting with symptomatic splenomegaly and/or constitutional symptoms, in patients with a platelet count of ≥50 × 10 &sup9;/L.

When the Previous Line Falls Short

Patients on this pathway previously received ruxolitinib, fedratinib, or were enrolled in a clinical trial as their initial treatment approach.

Escalation to this protocol is indicated when that therapy fails to achieve both a spleen volume reduction of ≥35% and a total symptom score reduction of ≥50% from baseline at week 24.

Next-Line Direction

The next step involves a JAK inhibitor-based strategy, with agent selection determined by which therapy was used in the prior line. Clinical trial enrollment remains an alternative option throughout. The complete selection criteria, sequencing logic, and monitoring framework are available in the full protocol.

Primary goal: Spleen volume reduction of ≥35% at week 24.

Instant Access to Structured Evidence-Based Regimens

References

DOI: 10.1182/blood.2022017423

Symptomatic splenomegaly and/or symptoms. Non-low risk. PLT ≥50 × 10 &sup9;/L.

FEDR, if RUX first, or alternative available JAKis, or clinical trials. FEDR was developed after RUX failure in the JAKARTA-2 study.

A recent update with stringent criteria of RUX failure showed a 30% rate of SVR35 with a median DOR not reached, a TSS50 rate of 27%, and 1-year survival of 84%.

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