Canterbury DHB

Management

In early-stage PMF, no treatment may be required, although low dose aspirin should be considered – especially in patients aged over 60, or those with other vascular risk factors.

For active and progressive disease, the following are likely to be required:

• supportive care in the form of transfusion
• gout treatment and prophylaxis
• nutritional support
• management of splenomegaly

Hydroxyurea (1-2 g daily) may reduce spleen size, but may also worsen cytopenias. Occasionally, splenectomy or splenic irradiation may produce benefit.

Other cytotoxic drugs have not been helpful.

Interferon

The role of interferon in managing PMF remains somewhat controversial. It can help relieve symptoms such as splenomegaly in some patients, and data recently published by the FIM suggests treatment with pegylated interferon can reduce JAK2 allele burden in many patients (achieving molecular remission in a small percentage), possibly improving survival in intermediate or high-risk DIPSS score patients. Results of larger studies are awaited to confirm any survival benefit.

As of July 2018, pegylated interferon is not funded for this indication in New Zealand.

JAK2 inhibitors (ruxolitinib)

The COMFORT 1 and COMFORT 2 trials³ showed that, in patients with PMF, ruxolitinib helped improve:

• constitutional symptoms, such as:
  • pruritus
  • fatigue
  • night sweats
  • bone pain
• symptomatic splenomegaly
• anaemia

This symptomatic response was seen even in patients without a JAK2 mutation.

Improving symptoms can improve survival; however, JAK2 inhibitors do not alter disease progression so are best for patients who are not eligible for allogeneic hematopoietic cell transplantation (HCT).

As of July 2018, ruxolitinib and other JAK2 inhibitors are not funded in New Zealand.

Lenalidomide

Lenalidomide (with steroid) may improve anaemia in a minority of patients.

Erythropoietin

Erythropoietin, androgens, or danzol are helpful in combating anaemia in some patients. Erythropoietin is not funded for PMF in New Zealand.

Splenectomy and splenic irradiation

Splenectomy may be considered to help manage pain and refractory cytopenias; however, it is especially risky in patients with PMF with increased peri-operative and long-term post-operative complications. Splenic irradiation may be considered for symptomatic relief as a palliative measure, but benefit may only last 3–6 months.

Topic Code: 6244