Myeloproliferative neoplasms (MPNs): 7 questions, answered
May 21, 2021
Medically Reviewed | Last reviewed by an MD Anderson Cancer Center medical professional on May 21, 2021
Myeloproliferative neoplasms (MPNs) are a group of rare chronic blood cancers that are often challenging to treat,with few approved treatments currently available. Researchers at MD Anderson's Hanns A. Pielenz Clinical Research Center for Myeloproliferative Neoplasms are working to better understand the diseases and find new, more effective medications to treat patients with MPNs.
To learn more about this group of diseases and new research and treatment options, we spoke with the center’s founder and director, Srdan Verstovsek, M.D., Ph.D.
What are myeloproliferative neoplasms (MPNs)?
Myeloproliferative neoplasms are a type of chronic cancer of the bone marrow that can worsen over time, especially if left untreated. They occur when stem cells in the bone marrow grow out of control, leading to an increase of one or more of the three blood cell types that circulate around our body — red blood cells, white blood cells, and platelets. MPNs can produce specific features, like scarring of the bone marrow, excess cells in the bone marrow and certain genetic mutations.
What are the major subtypes of myeloproliferative neoplasm?
There are three major myeloproliferative neoplasm subtypes: myelofibrosis (MF), polycythemia vera (PV) and essential thrombocythemia (ET). Each subtype has different clinical characteristics and a range of abnormalities:
- Myelofibrosis occurs when bone marrow is progressively replaced with fibers, reducing its ability to produce blood cells. Symptoms include headaches, night sweats, bone pain, itching, fatigue, unintentional weight loss, and spleen enlargement. It is the most aggressive type of MPN, while polycythemia vera and essential thrombocythemia typically progress more slowly and have better prognoses.
- Polycythemia vera is characterized by an increased number of red blood cells and a mutation called JAK2. Patients with this subtype have a high risk of blood clotting and hemorrhage. Patients can experience similar symptoms as patients with myelofibrosis.
- Essential thrombocythemia is characterized by a high number of platelets, the cells that control bleeding. Patients with this subtype commonly experience fatigue, headaches and increased risk of hemorrhage.
In about one-fourth of cases, MPNs progress to acute myeloid leukemia (AML), which is a disease where immature (“baby”) bone marrow cells called blasts start to grow out of control and do not mature. In acute myeloid leukemia patients, the bone marrow is not able to produce normal blood cells, the patient’s immune system is weakened and life expectancy is shortened.
How are myeloproliferative neoplasms diagnosed?
MPNs are diagnosed using physical exams, blood tests and bone marrow biopsies. When possible, physicians also order molecular tests to identify specific mutations in the bone marrow and blood cells. Physicians may also have the patient complete a standardized 10-question survey called the Myeloproliferative Neoplasm 10 (MPN10) Questionnaire. The Total Symptom Score (TSS) is calculated from the patient’s responses; it helps the doctor evaluate disease severity and quality of life. The physician takes into consideration the TSS as a guide to manage the patient’s personal treatment plan.
Why is it important to receive MPN treatment at a center where the physicians have experience with this disease?
MPNs are a challenging group of rare bone marrow and blood cancers, so it’s very important to seek diagnosis and treatment at a comprehensive cancer center like MD Anderson that has experts who specialize in treating MPNs. It’s important that specialized pathologists and physicians work together to accurately diagnose and effectively treat and manage patients with MPNs.
As the largest center in the world dedicated to this disease, MD Anderson’s Clinical Research Center for MPN treats more patients with this disease than any place else. That also means we have a large support network and many educational opportunities for patients.
How are MPNs treated?
The way we treat MPNs depends, in part, on the subtype, how advanced it is and other clinical factors. MPN treatments include JAK inhibitors (ruxolitinib, fedratinib), cytoreductive agents (hydroxyurea, interferons), aspirin, phlebotomy, medications and red blood cell transfusions for anemia, and, in some cases, stem cell transplants.
Why do JAK inhibitors like ruxolinitib play such an important role in treatment of myeloproliferative neoplasms?
The JAK2 mutation is present in 95% of patients with polycythemia vera, and it has been found in 50% to 60% of patients with myelofibrosis and essential thrombocythemia. Ruxolitinib inhibits the activity of the kinases (proteins) JAK1 and JAK2.
MD Anderson clinical trials led to the Food and Drug Administration’s approval of ruxolitinib as the frontline medication for myelofibrosis in 2011; this drug is now the standard of care for patients with this disease. It was approved as the second-line treatment for polycythemia vera in 2014.
Ruxolitinib was the first and only medication that was approved for myelofibrosis until 2019 when the JAK2 inhibitor called fedratinib was approved. Prior to the clinical development of ruxolitinib, there were few treatments for myelofibrosis, and the quality of life for patients with this subtype was very poor. Treatment with ruxolitinib has dramatically improved the patients’ quality of life and prolonged survival.
What are the next steps to improve treatment for MPNs?
This is a very exciting time because many new medications are being developed to treat MPNs. At MD Anderson, our team of experts is leading advanced-phase clinical trials to test several new MPN medications. They’re being investigated either as monotherapies, where patients are treated with just one drug, or in combination with other drugs such as ruxolitinib. These newer medications might improve issues, like anemia and low platelet counts, that haven’t been addressed by the existing therapies, and they might provide treatment options for patients who develop resistance or intolerance to JAK inhibitors. Clinicians and researchers are also developing new therapies that may prevent MPNs from progressing to AML and prolong patients’ survival.
Request an appointment at MD Anderson online or by calling 1-877-632-6789.
Myeloproliferative neoplasms (MPNs) [NR1] are a group of rare chronic blood cancers that are often challenging to treat,with few approved treatments currently available. Researchers at MD Anderson's Hanns A. Pielenz Clinical Research Center for MPN are working to better understand the diseases and find new, more effective medications to treat patients with MPNs.
To learn more about this group of diseases and new research and treatment options, we spoke with the center’s founder and director, Srdan Verstovsek, M.D., Ph.D.
What are myeloproliferative neoplasms?
Myeloproliferative neoplasms are a type of chronic cancer of the bone marrow that can worsen over time, especially if left untreated. They occur when stem cells in the bone marrow grow out of control, leading to an increase of one or more of the three blood cell types that circulate around our body — red blood cells, white blood cells, and platelets. MPNs can produce specific features, like scarring of the bone marrow, excess cells in the bone marrow and certain genetic mutations.
What are the major subtypes of myeloproliferative neoplasm?
There are three major myeloproliferative neoplasm subtypes: myelofibrosis (MF), polycythemia vera (PV) and essential thrombocythemia (ET). Each subtype has different clinical characteristics and a range of abnormalities:
Myelofibrosis occurs when bone marrow is progressively replaced with fibers, reducing its ability to produce blood cells. Symptoms include headaches, night sweats, bone pain, itching, fatigue, unintentional weight loss, and spleen enlargement. It is the most aggressive type of MPN, while polycythemia vera and essential thrombocythemia typically progress more slowly and have better prognoses.
Polycythemia vera is characterized by an increased number of red blood cells and a mutation called JAK2. Patients with this subtype have a high risk of blood clotting and hemorrhage. Patients can experience similar symptoms as patients with myelofibrosis.
Essential thrombocythemia is characterized by a high number of platelets, the cells that control bleeding. Patients with this subtype commonly experience fatigue, headaches and increased risk of hemorrhage.
In about one-fourth of cases, MPNs progress to acute myeloid leukemia (AML), which is a disease where immature (“baby”) bone marrow cells called blasts start to grow out of control and do not mature. In acute myeloid leukemia patients, the bone marrow is not able to produce normal blood cells, the patient’s immune system is weakened and life expectancy is shortened
How are myeloproliferative neoplasms diagnosed?
MPNs are diagnosed using physical exams, blood tests and bone marrow biopsies. When possible, physicians also order molecular tests to identify specific mutations in the bone marrow and blood cells. Physicians may also have the patient complete a standardized 10-question survey called the Myeloproliferative Neoplasm 10 (MPN10) Questionnaire. The Total Symptom Score (TSS) is calculated from the patient’s responses; it helps the doctor evaluate disease severity and quality of life. The physician takes into consideration the TSS as a guide to manage the patient’s personal treatment plan.
Why is it important to receive MPN treatment at a center where the physicians have experience with this disease?
MPNs are a challenging group of rare bone marrow and blood cancers, so it’s very important to seek diagnosis and treatment at a comprehensive cancer center like MD Anderson that has experts who specialize in treating MPNs. It’s important that specialized pathologists and physicians work together to accurately diagnose and effectively treat and manage patients with MPNs.
As the largest center in the world dedicated to this disease, MD Anderson’s Clinical Research Center for MPN treats more patients with this disease than any place else. That also means we have a large support network and many educational opportunities for patients.
How are MPNs treated?
The way we treat MPNs depends, in part, on the subtype, how advanced it is and other clinical considerations. Treatment can include combinations of drugs that inhibit particular genes and aim to reduce the number of cancer cells in the bone marrow, aspirin, steroids and stem cell transplants.
The JAK1/2 inhibitor drug ruxolinitib is especially promising for treatment of MPNs.
Why do JAK inhibitors like ruxolinitib play such an important role in treatment of myeloproliferative neoplasms?
The JAK2 mutation is present in 95% of patients with polycythemia vera, and it has been found in 50% to 60% of patients with myelofibrosis and essential thrombocythemia. Ruxolitinib inhibits both the JAK1 and JAK2 genes.
MD Anderson clinical trials led to the Food and Drug Administration’s approval of ruxolitinib as the frontline medication for myelofibrosis in 2011; this drug is now the standard of care for patients with this disease. It was approved as the second-line treatment for polycythemia vera in 2014.
Ruxolitinib was the first and only medication that was approved for myelofibrosis until 2019 when the JAK2 inhibitor called fedratinib was approved. Prior to the clinical development of ruxolitinib, there were few treatments for myelofibrosis, and the quality of life for patients with this subtype was very poor. Treatment with ruxolitinib has dramatically improved the patients’ quality of life and prolonged survival.
What are the next steps to improve treatment for MPNs?
This is a very exciting time because many new medications are being developed to treat MPNs. At MD Anderson, our team of experts is leading advanced-phase clinical trials to test several new MPN medications. They’re being investigated either as monotherapies, where patients are treated with just one drug, or in combination with other drugs such as ruxolitinib. These newer medications might improve issues, like anemia and low platelet counts, that haven’t been addressed by the existing therapies, and they might provide treatment options for patients who develop resistance or intolerance to JAK inhibitors. Clinicians and researchers are also developing new therapies that may prevent MPNs from progressing to AML and prolong patients’ survival.
Request an appointment at MD Anderson online or by calling 1-877-632-6789.
Link to: https://www.mdanderson.org/cancer-types/myeloproliferative-neoplasm.html [NR1]
Topics
Myeloproliferative NeoplasmThis is a very exciting time because many new medications are being developed to treat MPNs.
Srdan Verstovsek M.D., Ph.D.
Physician & Researcher