Have you been diagnosed with myelofibrosis and taken an approved JAK inhibitor to treat it?

Learn more about participating in the MOMENTUM Clinical Trial for Patients with Myelofibrosis.

What Is Myelofibrosis?

Myelofibrosis (MF) is a chronic blood cancer where scar tissue forms in the bone marrow, ultimately impairing the production of blood cells.

This scar tissue is caused by abnormal blood stem cells in the bone marrow, which divide too quickly, leading to decreased marrow function and inflammation both within the bone marrow and throughout the body. As a result of progressive bone marrow failure, patients often become increasingly anaemic and dependent on frequent blood transfusions over time. In addition, the spleen attempts to compensate for poor blood cell production causing it to become enlarged (known as splenomegaly). The enlarged spleen itself may cause discomfort, pain, fatigue and a decreased appetite adding to the symptoms caused by chronic inflammation, low blood cell production, and disease burden.

Classified as a myeloproliferative neoplasm (MPN), myelofibrosis can arise on its own or as a progression from polycythaemia vera (post-PV-MF) or essential thrombocythaemia (post-ET-MF).

3 Main Ways Myelofibrosis Affects People

From the outside, many people with myelofibrosis look the same as their healthy friends and family. But inside, patients are often experiencing:

Impaired Blood Cell Production:

Reduced red blood cells (anaemia), white blood cells (leukopenia), and platelets (thrombocytopenia)

Constitutional Symptoms:

Fatigue/tiredness, night sweats, itching, bone pain, inactivity, concentration problems, and weight loss

Enlarged Spleen (Splenomegaly):

Abdominal pain, a feeling of early fullness, bloating and high pressure in the liver vasculature

Common signs and symptoms of Myelofibrosis may include:

Anaemia, including a need for blood transfusions

An enlarged spleen and occasionally liver or other organs

Tiredness, weakness or shortness of breath with mild exertion

Fullness, discomfort or pain in the left upper area of the abdomen


Night sweats

Bone pain

Itching (pruritus)

Easy bleeding or bruising

Susceptibility to infection

Haziness or “Brain Fog”

Additional Resources:

Further information on Myelofibrosis is available through the MPN Research Foundation

About the MOMENTUM Clinical Trial for Patients with Myelofibrosis

The MOMENTUM Clinical Trial for Patients with Myelofibrosis will evaluate the effectiveness and safety of the investigational drug, momelotinib, compared to another drug (danazol), in treating myelofibrosis. Patients who participate in the clinical trial will randomly be assigned so that 120 patients receive momelotinib and 60 patients receive danazol, for a total of 180 patients.

Momelotinib is a type of drug known as a Janus kinase (or JAK) inhibitor which is designed to address the three major problems of myelofibrosis including the debilitating symptoms; anaemia (low red blood cell counts), or other low blood cell counts; and an enlarged spleen. Because momelotinib inhibits the JAK enzymes and another enzyme target involved in red blood cell production, called ACVR1, it may be able to treat myelofibrosis symptoms and enlarged spleen while also increasing red blood cell numbers, improving anaemia. This profile makes momelotinib different to other JAK inhibitors currently available which do not treat anaemia and usually make it worse.

Momelotinib treatment will be compared to that of danazol which is a drug listed as a potential treatment option for myelofibrosis patients with anaemia. It works in a completely different way to momelotinib and is not a JAK inhibitor.

What to Expect with Participation?

Momelotinib is a potential new therapy for myelofibrosis which has already been investigated in more than 820 myelofibrosis patients in earlier studies. Patients who wish to participate in the new MOMENTUM Clinical Trial will first be required to pass a period of screening to ensure they are suitable to enter the trial.


The screening period may last for up to 6 weeks prior to the first treatment dose. You will be asked to come in for a visit to speak with your doctor and nursing staff and ensure you meet all of the requirements for the MOMENTUM Clinical Trial.


The trial drug treatment period consists of two phases. In the first phase you will receive either momelotinib or danazol along with an inactive placebo as a part of your trial drug dosing. These drugs can be taken orally at home every day for 24 weeks.

In the second phase, which starts after you have been taking the trial drug for 24 weeks, you will be offered to stay on your treatment from the first phase or switch to momelotinib, depending on what treatment you were originally assigned to. Treatment in the second phase can continue for up to 4 years if you and your doctor believe momelotinib is safe for you and you are receiving benefit from treatment.

During the first year, you will visit the site every 4 weeks and then every 3 months after that.


You will be asked to return to the trial site 30 days after your last treatment dose, and then you will be contacted by trial staff periodically after that.

Am I Eligible? Is my Loved One Eligible?

You or someone you know may be eligible for the MOMENTUM Clinical Trial if you/they:

Are 18 years of age or older

Have received a diagnosis of myelofibrosis

Are currently or were previously treated with an approved JAK inhibitor (including either ruxolitinib or fedratinib) for myelofibrosis for a period of greater than 3 months (or greater than 28 days if blood related side-effects were experienced while on the drug)

Are anaemic AND have a significant symptom burden according to the definition used in the clinical trial protocol

A number of other criteria must be met before you/they may participate in the clinical trial. Your doctor and nursing staff will be familiar with what these requirements are and will be able to discuss these with you.

What possible benefits can I expect from taking part in this clinical trial?

Although more than 820 myelofibrosis patients have received momelotinib in earlier studies, there is no guarantee that you will receive personal benefit from taking part in this trial.

Clinical trials such as this are a way to determine if a drug is useful in treating a disease. By taking part in the trial you may benefit if momelotinib or danazol are effective in treating the symptoms of myelofibrosis, improving your anaemia or decreasing the size of your enlarged spleen. The trial drugs are not expected to cure you completely of your myelofibrosis so that no further treatment is required.

You will also benefit from the close medical monitoring of your health condition through blood tests and other evaluations during clinic visits. Finally, your taking part in the trial may benefit the community, scientists, doctors, the sponsor of the trial, Sierra Oncology, or other companies who are developing treatments for myelofibrosis by providing increased knowledge and information about the treatment of your disease and potentially helping momelotinib be approved for wider use.

If you are interested in learning more about this study, please visit clinicaltrials.gov or contact sierra_momentum_ct.gov@clin-edge.com

Frequently Asked Questions

What is an investigational medicine?

An investigational medicine is tested in the laboratory and clinical trials by scientists and doctors for research purposes, but it is not yet approved for commercial sale. A clinical trial tests the safety and efficacy of an investigational medication, in addition to how well it works to address therapeutic needs of the disease.

How does a clinical research trial evaluate new, investigational medicines?

Research trials are carefully designed to assess investigational medicines. Specific criteria are developed to determine if you are eligible to participate, you must follow a consistent drug dosing regimen and attend scheduled clinic visits, and you will undergo medical/behavioural tests and assessments. A team of trial coordinators, nurses and doctors works closely with you throughout the process to monitor any symptoms or changes, and to collect information on how you are feeling and reacting to the treatment. The information collected during the course of the trial is carefully reviewed, verified and analysed to determine the risks and benefits of the investigational medicine. Generally, favourable results from more than one trial are needed before an investigational medicine can be approved for sale to the public.

How are my rights and safety protected as a participant during a clinical trial?

Your rights, well-being, and safety are of the utmost importance to the clinical trial staff during and beyond the trial. Staff will explain all aspects of the trial to you and will answer any questions you may have. All clinical trials must follow strict guidelines on how participants are treated. The trial has been reviewed and approved by an Ethics Committee and/or Institutional Review Board, which are independent bodies set up to safeguard people taking part in medical research.

Can I leave the clinical trial before it ends?

It is important to remain in the clinical trial for its entire duration, but you have the right to leave at any time and for any reason. If you do decide to leave the trial, ensure you speak with the trial doctor first to determine how it may affect your health and what other treatment options are available.

Will compensation be provided?

You will not be paid to participate in this trial. You may receive reimbursement for reasonable travel expenses to attend your trial visit. A member of the clinical trial team will explain this in detail to you.

How can I learn more about the investigational medication and this clinical trial?

Additional information regarding this investigational medicine and clinical trial can be found on clinicaltrials.gov, on this website or on sierraoncology.com.

Trial Locations