Myelofibrosis

Treatment Planning 

Progress in understanding and treating myelofibrosis in recent years is offering hope to many people diagnosed with this rare form of blood cancer. Research in clinical trials continues to search for new treatments and ways to manage the side effects of the disease and improve patients’ quality of life.

Finding a blood cancer specialist with expertise in treating myelofibrosis is highly recommended because many oncologists simply do not have experience with it. A general hematologist/oncologist can give you a referral to a specialist. A second opinion from a specialist is important to confirm the diagnosis and treatment plan. Because myelofibrosis can affect many systems in the body, you will likely work with a multidisciplinary team that will co-manage your treatment.

Myelofibrosis is often treated like a chronic condition that will progress. For the majority of patients, the main goal is to minimize symptoms, which includes improving blood counts and reducing the chance of progression to acute myeloid leukemia. Your doctor will base your treatment on several factors – your symptoms, age and general health – that are combined into a risk score, which is assigned at diagnosis. The more aggressive the disease, the more aggressive the treatment is likely to be.

The Dynamic International Prognostic Scoring System (DIPSS) Plus includes four risk groups, ranging from low to high. It divides risk into four tiers: low risk, intermediate-1 risk, intermediate-2 risk and high risk. In general, patients in the low-risk group, who may or may not have symptoms, may be treated with watchful waiting, a clinical trial or targeted therapy. Patients in the high-risk group may receive a stem cell transplant, targeted therapy or a clinical trial. Multiple prognostic scoring systems exist. Some differentiate between whether patients are asymptomatic or symptomatic. If you are unsure which one your doctor used, ask.

Be aware that it is common for the treatment strategy you begin with to change. Your doctor will continually monitor your condition and make adjustments to your treatment plan for a number of reasons. Sometimes a therapy becomes less effective as time goes on; other times, a new mutation may be discovered and a different therapy may offer more promise. Keep in mind that cancer can be ever-changing, which presents many challenges, so flexibility and patience are important.

Following are descriptions of the most common treatment options. They may be used alone or in combination.

Watchful Waiting

This approach delays active treatment while closely monitoring the course of the cancer and its symptoms. It may be recommended for people with slow-growing disease or those who have very mild or no symptoms. This option, typically for people who are in the lower risk groups, offers the possibility of avoiding the side effects of treatment as long as possible. However, treatment should begin as soon as symptoms appear or test results show the disease is progressing.

Stem Cell Transplantation

At this time, the only potential cure for myelofibrosis is a stem cell transplant. Also known as bone marrow transplantation, a stem cell transplant involves an infusion of healthy stem cells into the body, typically after chemotherapy. It is only recommended for intermediate- and high-risk patients.

The most common type used is an allogeneic (pronounced al-oh-jeh-NAY-ik) stem cell transplant, which uses stem cells donated by a family member or an unrelated donor identified through a national or international registry. Other less-matched donor options are under investigation and in clinical trials to provide access for patients who have no available matched donor.

For the donor stem cells to be effective, transplant recipients must first receive a conditioning treatment, consisting of chemotherapy and possibly radiation therapy, to weaken their own stem cells and allow the donor stem cells to replace them and start fighting the cancer. High-dose or myeloablative conditioning treatments are often reserved for transplant candidates in excellent health and with very active and aggressive cancer.

This procedure may be too risky for some older patients who have other health problems, so you are encouraged to discuss this option with a doctor and a transplant center with extensive experience. Some treatment centers offer financial assistance with travel and temporary lodging during treatment. Talk with your health care team at the transplant center and advocacy organizations to learn about the resources available to assist you.

A non-myeloablative stem cell transplant or mini-transplant may be an option for older, sicker patients. A reduced-intensity conditioning treatment uses milder doses of chemotherapy and radiation therapy for conditioning prior to the transplant. The potential success of this approach depends entirely on the anti-cancer effect of the new immune system transplanted into the patient.

Talk with your doctor about the benefits and risks so you know what to expect with this treatment option. This includes potential short-term or long-term side effects, as well as the amount of help you will need from a caregiver. If a family member or friend cannot help, you may need to consider hiring a temporary caregiver because assistance will be necessary during this time.

The allogeneic stem cell transplantation process has four distinct phases:

1. Donor identification and evaluation, which includes tissue typing of related and unrelated donors, selecting the best match and requesting a thorough health evaluation of the donor as well as availability for the transplant time frame.

2. Conditioning, which includes chemotherapy and radiation therapy.

3. Stem cell infusion, during which the harvested donor stem cells are put into the recipient’s body intravenously (through a vein).

4. Recovery and engraftment, in which healthy cells begin to grow. There are typically signs of this in the first 30 days, but an enlarged spleen and scar tissue in the bone marrow, common in patients with myelofibrosis, can delay the engraftment process compared to that for other diseases. The patient will be at risk for bleeding and infection while the weakened immune system recovers. This process may take multiple years and will require ongoing use of prophylactic antiviral and antibacterial medications as well as repeat inoculations with childhood vaccines. The number of red cells, white cells and platelets will continue to be monitored until they are back to safe levels. Long-term monitoring and management of Graft-versus-Host Disease (GvHD) will also occur, if applicable. Transplant recipients may require lifelong treatment for GvHD.

Clinical Trials

Medical research studies may offer access to therapies not yet widely available for myelofibrosis. Ask your doctor whether you should consider a clinical trial at any time during your treatment.

Drug Therapy

Targeted therapy drugs are used to slow or stop the progression of disease. These drugs may be given orally as a pill. They travel throughout the body via the bloodstream and primarily affect cancer cells, leaving healthy cells alone.

The drugs approved are kinase inhibitors that block a type of enzyme called a kinase. Tyrosine kinases are a part of many cell functions, including cell signaling, growth and division. These enzymes may be too active or found at high levels in some cancer cells, and blocking them may help keep cancer cells from growing. In myelofibrosis, drugs are approved that target JAK1, JAK2 and/or FLT3, which are enzymes involved with blood cell production. Current therapies treat primary or secondary myelofibrosis that is intermediate, intermediate-2 or high risk.

This treatment does not alter the natural course of the illness, but it is used to decrease spleen size and improve symptoms. Because the currently approved targeted therapies can worsen low blood counts, they must be used with caution and frequent monitoring, if at all.

Chemotherapy travels through the bloodstream and kills rapidly growing cells in the body. It may be given intravenously (IV) into a vein or taken orally as a pill. It is often used in high doses to prepare for a stem cell transplant. In some cases, it is used to treat symptoms of anemia or to reduce high platelet and white blood cell counts.

Immunotherapy in the form of immunomodulators can be used to slow the growth of cancer by reducing the number of blood cells.

Corticosteroids are drugs used to treat some blood cancers and can help anemia, nausea, vomiting, weight loss, fatigue, night sweats and fevers. They can be used alone or in combination with other types of anti-emetic (anti-nausea) therapy.

Radiation Therapy

High-energy radiation to destroy cancer cells and shrink tumors may be given to prepare for an allogeneic stem cell transplant, reduce the size of the spleen, decrease bone pain or shrink tumors that have developed outside of the marrow.

Surgery

This treatment is primarily used to remove the spleen (a procedure called a splenectomy) if it becomes very large, is causing anemia or is lowering platelet counts. 


Common Drug Therapies
fedratinib (Inrebic)
hydroxyurea
interferon
pacritinib (Vonjo)
ruxolitinib (Jakafi)

As of 10/13/22

Donors Can Save Lives

At any given moment, thousands of people need lifesaving blood stem cell transplants but have no available donor. Organizations such as Be The Match (operated by the National Marrow Donor Program) have created registries of millions of potential donors. Minority donors are especially needed. Learn more at www.bethematch.org