Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Not recruitingRare disease

Study of Pacritinib for Patients with Severe Thrombocytopenia in Myelofibrosis Conditions

Verified siteRegistered drugNo placebo
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a group of diseases known as myelofibrosis, which includes Primary Myelofibrosis, Post-Polycythemia Vera Myelofibrosis, and Post-Essential Thrombocythemia Myelofibrosis. These conditions are characterized by the scarring of bone marrow, which can lead to severe thrombocytopenia, a condition where there are low levels of platelets in the blood. The study is testing a treatment called Pacritinib, which is a potent and selective inhibitor of certain enzymes involved in the disease process. The trial will compare the effectiveness of Pacritinib against other treatments chosen by doctors, referred to as "physician's choice" therapies. These other treatments may include medications like Hydroxycarbamide, Ruxolitinib, Methylprednisolone, Danazol, Prednisolone, and Dexamethasone.

The purpose of the study is to evaluate how well Pacritinib works in reducing the size of the spleen and improving symptoms in patients with myelofibrosis. The study will last for a period of 24 weeks, during which patients will receive either Pacritinib or one of the physician's choice therapies. Throughout the study, patients will undergo regular assessments, including imaging tests like MRI or CT scans, to measure changes in spleen size and symptom severity. The study aims to determine if Pacritinib can achieve a significant reduction in spleen volume and improve the overall symptom score compared to the other treatments.

Participants in the study will be monitored for any side effects or adverse events, and their overall health will be assessed through various tests and evaluations. The study will also track the time it takes for any significant health changes to occur, such as improvements in symptoms or any serious health issues. The trial is expected to provide valuable information on the effectiveness and safety of Pacritinib for patients with severe thrombocytopenia due to myelofibrosis.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, you will be randomly assigned to receive either pacritinib or a treatment chosen by your doctor. This is to compare the effectiveness of the treatments.

    You will be informed about the specific treatment you will receive and any necessary instructions.

  2. Step 2

    Treatment administration

    If you are assigned to pacritinib, you will take it orally as a capsule. The dosage and frequency will be provided by your healthcare provider.

    If you are assigned to the treatment chosen by your doctor, it may include medications such as hydroxycarbamide, ruxolitinib, methylprednisolone, danazol, prednisolone, or dexamethasone. These are also taken orally, and your doctor will provide specific instructions.

  3. Step 3

    Regular assessments

    Throughout the study, you will undergo regular assessments to monitor your health and the effectiveness of the treatment.

    These assessments may include imaging tests like MRI or CT scans to measure changes in spleen size and symptom evaluations using a questionnaire.

  4. Step 4

    Symptom tracking

    You will be asked to complete symptom assessments using a patient-reported outcome instrument. This helps track any changes in your symptoms over time.

    It is important to provide accurate information to help evaluate the treatment's impact on your condition.

  5. Step 5

    End of treatment evaluation

    At the end of the treatment period, which is approximately 24 weeks, your progress will be evaluated.

    The evaluation will focus on the reduction in spleen size and symptom improvement, as well as any side effects experienced during the study.

  6. Step 6

    Follow-up

    After completing the treatment, there will be a follow-up period to monitor your health and any long-term effects of the treatment.

    This may include additional assessments and communication with your healthcare provider.

Who can join the trial?

16 criteria

  • Must have one of the following conditions: Primary Myelofibrosis, Post-Essential Thrombocythaemia Myelofibrosis, or Post-Polycythaemia Vera Myelofibrosis.
  • Must have a platelet count (a type of blood cell) of less than 50,000 per microliter at the time of screening.
  • Must be classified as Intermediate-1, Intermediate-2, or High-Risk according to the Dynamic International Prognostic Scoring System.
  • Must have a palpable spleen enlargement of at least 5 cm below the rib cage as determined by a physical exam.
  • Must have a Total Symptom Score (TSS) of 10 or more, or a single symptom score of 5 or more, or two symptoms scoring 3 or more, including symptoms like left upper quadrant pain, bone pain, itching, or night sweats.
  • Must be at least 18 years old.
  • Must have an Eastern Cooperative Oncology Group performance status of 0 to 2, which measures daily living abilities.
  • Must have a peripheral blast count (immature blood cells) of less than 10% during the screening period.
  • Must have an absolute neutrophil count (a type of white blood cell) of at least 500 per microliter.
  • Must have a left ventricular cardiac ejection fraction of 50% or more, which measures heart function, as determined by an echocardiogram or similar test.
  • Must have adequate liver and kidney function, with specific blood test results within certain limits.
  • Must have adequate blood clotting ability, as shown by specific blood tests.
  • If capable of having children, must agree to use highly effective birth control methods during the study.
  • Must be willing to have and able to tolerate frequent MRI or CT scans during the study.
  • Must be able to understand and willing to complete symptom assessments using a patient-reported outcome tool.
  • Must provide signed informed consent to participate in the study.

Who cannot join the trial?

10 criteria

  • Patients with any other serious medical condition that might affect their participation in the study.
  • Patients who have had a recent heart attack or stroke.
  • Patients with uncontrolled high blood pressure.
  • Patients with severe liver disease.
  • Patients with severe kidney disease.
  • Patients who are pregnant or breastfeeding.
  • Patients who are currently participating in another clinical trial.
  • Patients who have had an allergic reaction to the study medication or similar medications in the past.
  • Patients with a history of certain types of cancer.
  • Patients with active infections that require treatment.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Not recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

  • Pacritinib

    is a medication being studied for its potential to help people with a type of blood cancer called myelofibrosis, especially those who have very low platelet counts. Myelofibrosis is a condition where the bone marrow, which is responsible for producing blood cells, becomes scarred and doesn't work properly. This can lead to an enlarged spleen and other symptoms. Pacritinib is designed to target specific pathways in the body that contribute to the disease, with the goal of reducing the size of the spleen and improving symptoms.

  • Physician's Choice Therapy

    refers to a treatment option where the doctor selects the best available therapy for the patient based on their individual needs and medical history. This could include a variety of medications or therapies that are already approved and commonly used for treating myelofibrosis. The idea is to compare the effectiveness of pacritinib against these standard treatments to see which works better for patients with severe thrombocytopenia, a condition where there are fewer platelets in the blood than normal.

What is already known about the treatment

Pacritinib – Pacritinib is administered orally in the form of a capsule. It is currently being studied in clinical trials for its effectiveness in treating certain types of myelofibrosis, a condition where scar tissue forms in the bone marrow. The main therapeutic indications for pacritinib include primary myelofibrosis, post-essential thrombocythemia myelofibrosis, and post-polycythemia vera myelofibrosis, especially in patients with severe thrombocytopenia, which means they have very low platelet counts. At the molecular level, pacritinib works by inhibiting specific enzymes called Janus kinases (JAK2 and FLT3), which are involved in the signaling pathways that control blood cell production and immune function. It is classified pharmacologically as a kinase inhibitor.

Investigated diseases

  • Primary Myelofibrosis

    Primary Myelofibrosis is a chronic disorder where the bone marrow is replaced by fibrous tissue, leading to a decrease in blood cell production. This condition often begins with an enlarged spleen and progresses with symptoms such as fatigue, weakness, and anemia. Over time, the fibrous tissue in the bone marrow increases, further reducing the production of blood cells. Patients may experience weight loss, night sweats, and bone pain as the disease advances. The condition can lead to significant changes in blood cell counts, including low red blood cells, white blood cells, and platelets. As the disease progresses, it can cause complications related to blood cell deficiencies.

  • Post-Essential Thrombocythaemia Myelofibrosis

    Post-Essential Thrombocythaemia Myelofibrosis is a condition that develops in some patients who have had essential thrombocythaemia, a disorder characterized by an overproduction of platelets. Over time, the bone marrow becomes fibrotic, leading to a reduction in blood cell production. This progression results in symptoms such as fatigue, anemia, and an enlarged spleen. Patients may also experience weight loss, night sweats, and bone pain. The disease causes significant changes in blood cell counts, including low levels of red blood cells and platelets. As the condition advances, it can lead to complications associated with blood cell deficiencies.

  • Post-Polycythaemia Vera Myelofibrosis

    Post-Polycythaemia Vera Myelofibrosis occurs in some individuals who have had polycythaemia vera, a condition where there is an overproduction of red blood cells. Over time, the bone marrow becomes fibrotic, reducing its ability to produce blood cells. This leads to symptoms such as fatigue, anemia, and an enlarged spleen. Patients may also experience weight loss, night sweats, and bone pain. The disease results in significant changes in blood cell counts, including low levels of red blood cells and platelets. As the condition progresses, it can cause complications related to blood cell deficiencies.

Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-515953-52-00Protocol codePAC303Estimated enrolment399 patientsSponsorSobi Inc.

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.