The pharmacotherapeutic management of patients with myelofibrosis: looking beyond JAK inhibitors

Renal extramedullary hematopoiesis as an epiphenomenon of bone marrow dysfunction in a patient with primary myelofibrosis: A rare case report

Extramedullary hematopoiesis represents a clinical compensatory condition characterized by the growth of hematopoietic tissue outside the bone marrow. It can mainly occur in patient with myeloproliferative disorders where alteration or neoplastic invasion of the bone marrow causes ineffective production of blood cells with the recruitment of progenitrix blood cells in non-hematopoietic organs, including kidneys. Renal extramedullary hematopoiesis is a rare condition manifesting as parenchymal or perirenal soft tissue masses with different patterns mimicking neoplasms, infectious or vascular diseases. We describe a unique case of a patient affected by primary myelofibrosis underwent ultrasound and magnetic resonance examinations showing bilateral perirenal alterations to be related to hemopoietic tissue. We also focused on the pathophysiology of this condition with imaging correlation. The case we present emphasises the importance of recognising the main radiological features of renal extramedullary hematopoiesis. MR examination should become part of the diagnostic pathway of the patient with primary myelofibrosis.

ACVR1: A Novel Therapeutic Target to Treat Anemia in Myelofibrosis

Activin receptor type I (ACVR1) is a transmembrane kinase receptor belonging to bone morphogenic protein receptors (BMPs). ACVR1 plays an important role in hematopoiesis and anemia via the BMP6/ACVR1/SMAD pathway, which regulates expression of hepcidin, the master regulator of iron homeostasis. Elevated hepcidin levels are inversely associated with plasma iron levels, and chronic hepcidin expression leads to iron-restricted anemia. Anemia is one of the hallmarks of myelofibrosis (MF), a bone marrow (BM) malignancy characterized by BM scarring resulting in impaired hematopoiesis, splenomegaly, and systemic symptoms. Anemia and red blood cell transfusions negatively impact MF prognosis. Among the approved JAK inhibitors (ruxolitinib, fedratinib, momelotinib, and pacritinib) for MF, momelotinib and pacritinib are preferably used in cytopenic patients; both agents are potent ACVR1 inhibitors that suppress hepcidin expression via the BMP6/ACVR1/SMAD pathway and restore iron homeostasis/erythropoiesis. In September 2023, momelotinib was approved as a treatment for patients with MF and anemia. Zilurgisertib (ACVR1 inhibitor) and DISC-0974 (anti-hemojuvelin monoclonal antibody) are evaluated in early phase clinical trials in patients with MF and anemia. Luspatercept (ACVR2B ligand trap) is assessed in transfusion-dependent MF patients in a registrational phase 3 trial. Approved ACVR1 inhibitors and novel agents in development are poised to improve the outcomes of anemic MF patients.

Polycythemia Vera: Barriers to and Strategies for Optimal Management

Polycythemia vera (PV) is a subtype of myeloproliferative neoplasms characterized by impaired quality of life and severe complications. Despite the increasingly in-depth knowledge of this condition, it necessitates a multifaceted management approach to mitigate symptoms and prevent thrombotic and hemorrhagic events, ensuring prolonged survival. The therapeutic landscape has been revolutionized in recent years, where venesection and hydroxycarbamide associated with antiplatelet therapy have a central role and are now accompanied by other drugs, such as interferon and Janus kinase inhibitors. Ongoing research and advancements in targeted therapies hold promise for further enhancing the therapeutic choice for PV management.

AIPSS-MF machine learning prognostic score validation in a cohort of myelofibrosis patients treated with ruxolitinib

BACKGROUND

In myelofibrosis (MF), new model scores are continuously proposed to improve the ability to better identify patients with the worst outcomes. In this context, the Artificial Intelligence Prognostic Scoring System for Myelofibrosis (AIPSS-MF), and the Response to Ruxolitinib after 6 months (RR6) during the ruxolitinib (RUX) treatment, could play a pivotal role in stratifying these patients.

AIMS

We aimed to validate AIPSS-MF in patients with MF who started RUX treatment, compared to the standard prognostic scores at the diagnosis and the RR6 scores after 6 months of treatment.

METHODS AND RESULTS

At diagnosis, the AIPSS-MF performs better than the widely used IPSS for primary myelofibrosis (C-index 0.636 vs. 0.596) and MYSEC-PM for secondary (C-index 0.616 vs. 0.593). During RUX treatment, we confirmed the leading role of RR6 in predicting an inadequate response by these patients to JAKi therapy compared to AIPSS-MF (0.682 vs. 0.571).

CONCLUSION

The new AIPSS-MF prognostic score confirms that it can adequately stratify this subgroup of patients already at diagnosis better than standard models, laying the foundations for new prognostic models developed tailored to the patient based on artificial intelligence.