John O Mascarenhas

John O Mascarenhas, MD

  • ASSOCIATE PROFESSOR | Medicine, Hematology and Medical Oncology


Cancer (Oncology), Hematology-Oncology

Dr. John Mascarenhas is a clinical investigator in malignant hematology with a focus in translational research involving the Myeloproliferative Neoplasms. Dr. Mascarenhas is primarily responsible for the clinical trials arm of the Mount Sinai School of Medicine Myeloproliferative Disorders Program headed by Dr. Ronald Hoffman. This program offers phase I/II and III studies for patients with myelofibrosis, polycythemia vera, essential thrombocythemia, chronic myelogenous leukemia, and forms of acute myeloid leukemia. In addition, Dr. Mascarenhas treats patients with myelodysplastic syndrome, hypereosinophilic syndrome, systemic mastocytosis, chronic myelomonocytic leukemia and related issues.

Clinical trials:

  • A Phase I/II Open Label Study of LBH589, a Novel Histone Deacetylase Inhibitor (HDACi), in Patients with Primary Myelofibrosis (PMF) and Post-Polycythemia/Essential Thrombocythemia Myelofibrosis (Post-PV/ET MF)
  • A Multicenter, Open Label Phase I / II Study of JAK2 inhibitor CEP-701 (Lestaurtinib) in Adults with Myelofibrosis
  • A Phase I/II, Open Label Multi-Centre Study to Assess the Safety, Tolerability, Pharmacokinetics and Preliminary Efficacy of the JAK2 inhibitor AZD1480 Administered Orally to Patients with Primary Myelofibrosis (PMF) and Post-Polycythaemia Vera/Essential Thrombocythaemia Myelofibrosis (Post-PV/ET MF)
  • Study of Fludarabine Based Conditioning for Allogeneic Stem Cell Transplantation for Myelofibrosis 
  • Phase I study of GC1008 in patients with primary myelofibrosis (PMF), post-polycythemia vera/essential thrombocythemia related myelofibrosis (post-PV/ET MF) and essential thrombocythemia (ET)

In this episode of "Healthy Body, Healthy Mind" Dr. Mascarenhas discusses myelofibrosis - including why it's an unfamiliar term for many people, the rarity of the disease, and the age at which most people are diagnosed.


Medical Oncology


Clinical Focus

  • Chronic Myelocytic Leukemia
  • Eosinophilia
  • Myelodysplastic Syndromes
  • Primary Polycythemia


MD, New York Medical College

Residency, Internal Medicine, Rhode Island Hospital

Fellowship, Hematology, Mount Sinai Hospital

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