# Case report: Effectiveness of low-dose methotrexate monotherapy in post-essential thrombocythemia myelofibrosis

## TL;DR

A 73-year-old woman with two chronic conditions improved significantly with low-dose methotrexate, possibly due to its effect on a shared signaling pathway.

## Contribution

This case report suggests methotrexate may be a cost-effective treatment for myeloproliferative neoplasms.

## Key findings

- Low-dose methotrexate improved both psoriasis and myelofibrosis symptoms in a patient.
- The drug was well tolerated and significantly enhanced the patient's quality of life.
- Methotrexate's potential as a JAK inhibitor may explain its effectiveness in these conditions.

## Abstract

JAK/STAT pathway signalling is associated with both chronic inflammatory conditions such as psoriasis and haematological malignancies such as the myeloproliferative neoplasms (MPNs). Here we describe a 73yo female patient with a history of chronic plaque psoriasis, post-essential thrombocythemia myelofibrosis (MF) and a quality of life substantially impacted by both conditions. We report that 15 mg oral Methotrexate (MTX) weekly as a monotherapy is well tolerated, provides a substantial clinical improvement for both conditions and significantly improves quality of life. We suggest that the recently identified mechanism of action of MTX as a JAK inhibitor is likely to explain this efficacy and suggest that repurposing MTX for MPNs may represent a clinical- and cost-effective therapeutic option.