Chokri Ben Lamine: Matching Anemia Treatment to the Myelofibrosis Patient

Chokri Ben Lamine, Hematologist at King Faisal Specialist Hospital and Research Center, shared a post on X:

“Managing anemia in myelofibrosis: match treatment to anemia, spleen burden and symptoms!

1. Start by identifying the cause before attributing anemia entirely to MF, assess:

• Bleeding or hemolysis
• Iron, vitamin B12 or folate deficiency
• Renal dysfunction
• Treatment-related marrow suppression
• Disease progression

RBC transfusions provide supportive care when clinically indicated.

2.The treatment framework shown.

The slide cites NCCN v2.2025, so its categories should be read in that context:

• Anemia and ongoing symptomatic splenomegaly/constitutional symptoms: momelotinib or a clinical trial; other listed approaches include pacritinib or ruxolitinib with anemia-directed therapy.
• Spleen/symptoms controlled on the current JAK inhibitor: consider adding an ESA, danazol or luspatercept, or switching JAK inhibitor when appropriate.
• Anemia without symptomatic spleen disease: prioritize anemia-directed treatment and clinical trials.

The slide uses serum EPO less than 500 mU/mL to identify patients for ESA consideration. Guideline inclusion and regulatory approval are separate considerations.

3.JAK inhibitors differ in their effects on anemia.

The slide reports all-grade anemia across selected trials:

• Ruxolitinib: approximately 31–60%
• Fedratinib: approximately 40–61%

These figures come from different populations and reporting methods—they cannot establish which drug causes more anemia.

A falling Hb during treatment requires assessment of timing, severity, transfusion burden and concurrent disease control.

4.Why momelotinib can help anemia

• Momelotinib inhibits JAK1/JAK2 and ACVR1/ALK2.

JAK inhibition addresses inflammatory signaling, spleen enlargement and symptoms.

ACVR1 inhibition lowers hepcidin – increases iron availability – supports erythropoiesis.

Connection to the preceding PV slides:

• Rusfertide mimics hepcidin to restrict erythropoiesis; momelotinib suppresses hepcidin to improve iron availability in MF.

Usual adult dose: 200 mg orally once daily. Its US indication covers intermediate/high-risk MF in adults with anemia.

Prescribing information

5.MOMENTUM : who was studied?

• Randomized, double-blind phase III trial; N equals 195, randomized 2:1.

Patients had:

• Prior JAK-inhibitor exposure
• Symptoms: total symptom score greater than or equal to 10
• Anemia: Hb less than 10 g/dL
• Platelets greater than or equal to 25 ×10⁹/L

Treatment:

• Momelotinib 200 mg/day versus danazol 600 mg/day
• Primary assessment: week 24.

MOMENTUM publication

6.MOMENTUM results at week 24

Momelotinib versus danazol:

• Greater than or equal to 50% symptom-score reduction: 25% vs 9%

Primary endpoint; superiority demonstrated.

• Transfusion independence: 30% vs 20%

The prespecified test demonstrated noninferiority, not superiority.

• Greater than or equal to 35% spleen-volume reduction: 22% vs 3%

Superiority demonstrated.

• No transfusions through week 24: 35% vs 17%

Superiority demonstrated.

Transfusion independence required no transfusions and no Hb less than 8 g/dL during weeks 12–24. It is different from receiving zero transfusions throughout the entire study period.

Trial results

7.Does achieving Hb Greater than or equal to 10 g/dL improve survival?

The exploratory analysis displayed reports:

• Hb greater than or equal to 10 at week 24: n equals 24
• Hb less than 10/nonachievement: n equals 102
• OS hazard ratio: 0.59; 95% CI 0.28–1.28

The confidence interval crosses 1: the survival difference was not statistically significant.

Patients were grouped by a response occurring after treatment began; early discontinuations counted as nonachievement. This creates potential selection and guarantee-time bias.

Appropriate conclusion: Hb improvement was associated with numerically longer survival; this analysis does not prove that correcting Hb prolongs life.”

Other posts featuring Chokri Ben Lamine on Hemostasis Today.