Looking Deeper Inside Myelofibrosis

A leading expert believes a clearer picture of MF is emerging

By Kristin Bundy

Kristin Bundy, reporting here for Her work regularly appears in publications, such as MedPage Today and Cancer Therapy Advisor.

“I remember when we didn't have a lot to offer patients with myelofibrosis, and the suffering was high,” says John Mascarenhas, MD, associate professor at Icahn School of Medicine, Mount Sinai, New York City. “But even now there are patients with low platelets and transfusion dependence who are not being served optimally.”

These cases—patients with cytopenias who are challenged by the myelosuppressive nature of current management options—are what motivate Dr. Mascarenhas and his research.

“Problem is, right now, we are trying to manage a heterogeneous disease in a homogeneous way.” For decades, Dr. Mascarenhas has interrogated the heterogeneity of MF and the inherent differences in pathophysiology between the two types—primary MF (PMF) and secondary MF (SMF).


Emerging data show two critical variations between the two phenotypes. PMF has a lower JAK2V617F allele burden but more driver mutations; whereas, SMF has a high JAK2V617F allele burden and is associated with just the single mutation.

In the clinic, patients with PMF are more likely to have low blood counts, be transfusion dependent, and have more aggressive disease. Prevalence is different, too. PMF represents 70% of all MF cases compared with SMF at about 30%.

By reclassifying the potential mechanistic differences between PMF and SMF, he believes the implications from his research may translatve to quicker diagnoses in the clinic.

“Collectively, I don't think any of us researchers are happy with where we are. We’re happy with where we've come from, but we're really looking to improve upon that.” He adds,

“I think we are ready for a second renaissance in the management of patients with PMF—one in which hematologists can address the needs of more of their patients.”


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