ClinicalTrials.gg
RecruitingNCT04644211Updated Jan 8, 2026

Ruxolitinib in Thrombocythemia and Polycythemia Vera

A Phase 2 interventional study of Ruxolitinib in Essential Thrombocythemia and Polycythemia Vera, sponsored by Massachusetts General Hospital. Recruiting at 4 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-01-08.

Sponsored by Massachusetts General Hospital · Phase 2, Interventional, and Treatment

From the registry’s dates

  • Started Mar 2022; still recruiting 4 years 7 months later.
Phase
Phase 2
Study type
Interventional
Enrollment
60
Allocation
Non-randomized
Ages
18 Years and older
Sex
All
01

Study summary

This research is being done to see if the drug ruxolitinib is effective in reducing the symptoms caused by low-risk essential thrombocythemia (ET) and polycythemia vera (PV).

- This research study involves the study drug Ruxolitinib.

Read the detailed description

This is a multi-center, non-randomized, two-stage phase II clinical trial evaluating ruxolitinib in low-risk but symptomatic essential thrombocythemia (ET) and polycythemia vera (PV) patients. This research is being done to see if Ruxolitinib is effective in reducing the symptoms people with essential thrombocythemia (ET) and polycythemia vera (PV) are experiencing. Ruxolitinib is a type of drug that blocks the specific proteins that may be causing the symptoms people with essential thrombocythemia (ET) and polycythemia vera (PV are experiencing.

The research study procedures include screening for eligibility and study treatment, including evaluations and follow up visits.

- Participants will receive Ruxolitinib for approximately 6 months and if benefitting from it may continue to receive Ruxolitinib for as long as there is no unacceptable side effects or disease progression.

It is expected that about 60 people will take part in this research study.

The U.S. Food and Drug Administration (FDA) has approved Ruxolitinib for polycythemia vera (PV) but not for people with essential thrombocythemia (ET) and polycythemia vera (PV).

Incyte, a biopharmaceutical company, is supporting this research study by providing funding for the study, including the study drug.

02

Conditions studied

  • Essential Thrombocythemia
  • Polycythemia Vera

Keywords

  • Essential Thrombocythemia
  • Polycythemia Vera
  • Sympton Burden
03

In context

Thrombocythemia, Essential

229 studies on the registry are indexed under Thrombocythemia, Essential; 38 are open to participants now.

This study's planned enrollment of 60 is above the median of 52 across 168 interventional studies indexed under Thrombocythemia, Essential.

Browse Thrombocythemia, Essential studies →

Lead sponsor

Massachusetts General Hospital is the lead sponsor of 2,586 studies on the registry; 447 are open to participants now.

Of its 222 completed or terminated interventional studies of FDA-regulated products, 168 (76%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Patients who have been diagnosed with essential thrombocythemia or polycythemia vera by World Health Organization 2016 diagnostic criteria.
  • Patients with essential thrombocythemia must be very low (no history of thrombosis, age \<60, and no JAK2 mutation), low (no history of thrombosis, age \<60, presence of JAK2 mutation), or intermediate risk (no history of thrombosis, age >60, no JAK2 mutation) by IPSET criteria. Patients with polycythemia vera must be low risk (no history of thrombosis and age \<60) by NCCN guidelines.
  • Patients with an MPN-SAF TSS (MPN-10) score >10 AND at least one individual feature >5 documented on a separate visit within 3 months prior to study registration, as documented in the clinical record or obtained by clinician. If not previously documented in the electronic medical record, participants must be blinded to purpose of MPN SAF TSS scoring for eligibility determination. Average daily MPN-SAF TSS (MPN-10) score must remain >10 with any individual feature >5 for the week-long baseline assessment prior to ruxolitinib initiation.
  • Patients who have previously received or are receiving cytoreductive therapy (i.e. hydroxyurea, anagrelide, interferon) are eligible for the study if therapy was used for the indication of symptom control, or if therapy was used for pre-operative control of blood counts. If a subject is still receiving cytoreductive therapy at the time of screening and enrollment, there will be a from prior cytoreductive therapy at least 7 days prior to ruxolitinib initiation.
  • Age ≥18 years.
  • performance status ≤2 ( ≥60%)
  • Participants must have adequate organ and marrow function as defined below:

    • leukocytes ≥3,000/mcL
    • ≥1,500/mcL
    • ≥100,000/mcL
    • total ≤ institutional (ULN)
    • (SGOT)/ALT(SGPT) ≤3 × institutional ULN
    • creatinine ≤ institutional ULN OR (GFR) ≥60 mL/min/1.73 m2 unless data exists supporting safe use at lower kidney function values, no lower than 30 mL/min/1.73 m2
  • Participants with a prior or concurrent not receiving treatment for concurrent cancer diagnosis and/or prior concurrent malignancy within 5 years except for basal cell carcinoma or squamous cell carcinoma of the skin.
  • For participants with evidence of chronic virus (HBV) infection, the HBV viral load must be undetectable on suppressive therapy, if indicated.
  • For participants with evidence of chronic (HIV) infection, they must be negative for HBV DNA, , or hepatitis B surface antigen (BsAg) on suppressive therapy, if indicated.
  • Participants must be previously vaccinated with the Herpes Zoster (Shingles) vaccine or must be willing to start prophylactic Acyclovir 400 mg twice daily (BID) or suitable alternative for duration of treatment with ruxolitinib.
  • Participants with known history or current symptoms of cardiac disease, or history of treatment with cardiotoxic agents, should have a clinical risk assessment of cardiac function using the Functional Classification. To be eligible for this trial, participants should be class 2B or better.
  • Ability to understand and the willingness to sign a written document.

Exclusion criteria

Exclusion Criteria:

  • Essential thrombocythemia patients who are high risk by IPSET-R criteria (age > 60 with JAK2 V617F mutation and/or history of thrombosis).1 Polycythemia vera patients who are high risk by NCCN guidelines (age > 60 and/or history of thrombosis).
  • Patients with >5% blasts on baseline marrow exam or at any other time in peripheral blood
  • Participants who are receiving any other agents.
  • Participants with a history of splenectomy. Participants may still be eligible after discussion with and approval by the Overall PI, however.
  • History of allergic reactions attributed to compounds of similar chemical or biologic composition to ruxolitinib or of ruxolitinib.
  • Participants requiring any medications or substances that are strong inhibitors or 3A4 isozyme are ineligible. Because the lists of these agents are constantly changing, it is important to regularly consult a frequently-updated medical reference. As part of the enrollment/ procedures, the participant will be counseled on the risk of interactions with other agents, and what to do if new medications need to be prescribed or if the participant is considering a new over-the-counter medicine or herbal product.
  • Participants with uncontrolled intercurrent illness.
  • Participants with inadequate liver or renal function at screening as evidenced by lab values not meeting criteria
  • Participants with psychiatric illness/social situations that would limit compliance with study requirements.
  • Pregnant women are excluded from this study because ruxolitinib is a Class C agent with the potential for teratogenic or abortifacient effects. Because there is an unknown but potential risk for adverse events in nursing infants secondary to treatment of the mother with ruxolitinib, breastfeeding should be discontinued if the mother is treated with ruxolitinib.
  • The effects of ruxolitinib on the developing human fetus are unknown. Pregnant women and subjects of who are unwilling to take appropriate precautions to avoid becoming pregnant or fathering a child are ineligible. Women of child-bearing potential and men must agree to use adequate (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately. Men treated or enrolled on this protocol must also agree to use adequate contraception prior to the study, for the duration of study participation, and 4 months after completion of ruxolitinib administration.
Terms in these criteria, in plain language(19)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Washout period

A planned gap after a treatment, so that its effects can lessen before the study treatment or a study assessment. Ask the study team and the doctor who prescribed it before changing any medicine.

ECOG performance status

A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.

0
Fully active, no restrictions.
1
Limited in strenuous activity, but walking and able to do light work, such as housework or office work.
2
Walking and able to look after yourself, but unable to work; up and about more than half of waking hours.
3
Able to look after yourself only in part; in bed or a chair more than half of waking hours.
4
Unable to look after yourself at all; in bed or a chair all day.

Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.

Karnofsky performance status (KPS)

A 0–100 scale of how well someone can carry out everyday activities. 100 is no complaints and no signs of illness; 70 is able to look after yourself but not to work or keep up normal activity; 50 is needing considerable help and frequent medical care.

Studies often ask for 60 or 70 and above. Your doctor gives the score.

Absolute neutrophil count (ANC)

The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.

It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.

Platelets

Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.

Bilirubin

A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.

Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.

ULN (upper limit of normal)

The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.

“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.

ALT and AST (liver enzymes)

Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.

Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.

GFR and eGFR (kidney filtering)

GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².

Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

NYHA class (heart failure)

The New York Heart Association’s four classes of how much heart failure limits physical activity.

I
No limits: ordinary activity causes no undue tiredness or breathlessness.
II
Slight limits: comfortable at rest, ordinary activity causes symptoms.
III
Marked limits: comfortable at rest, less than ordinary activity causes symptoms.
IV
Symptoms even at rest; any activity makes them worse.

Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Excipients

The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Non-randomized
Intervention model
Sequential assignment
Masking
None (open label)
Enrollment
60 participants (estimated)

Study arms

  • Experimental
    Ruxolitinib Stage 1

    In stage 1, participants will be divided into two cohorts: * Very low, Low, and Intermediate-risk ETpatients with significant symptom burden and Low-risk PV patients with significant symptom burden * Study cycles are 28 days long, participants in both cohorts will receive: * Ruxolitinib 2x daily for 6 study cycles.

    Drug: Ruxolitinib

  • Experimental
    Ruxolitinib Stage 2

    Stage 2 will commence based on 3 or more participants in Stage 1 showing a predetermined positive response to Ruxolitinib. In stage 2, participants will be divided into two cohorts: * Very low, Low, and Intermediate-risk ET patients with significant symptom burden and Low-risk PV patients with significant symptom burden * Study cycles are 28 days long, participants in both cohorts will receive: * Ruxolitinib 2x daily for 6 study cycles.

    Drug: Ruxolitinib

Interventions

  • Pill taken by mouth.

    Also known as: Jakafi

06

What researchers measure

Primary outcomes

  1. Percentage of patients who achieve >50% reduction from baseline to Myeloproliferative Neoplasm Symptom Assessment Total Symptom Score

    Percentage of patients with \>50% change in Myeloproliferative Neoplasm Symptom Assessment Total Symptom Score (MPN-SAF TSS), which has use in major clinical trials and as symptom assessment in all patients in clinical practice. Modeling has established baseline MPN-SAF TSS cut-off scores (total MPN-SAF TSS \>20 or an individual component score \>5) at which symptomatic treatment would be significantly beneficial

    Time frame: baseline to 12 weeks

Secondary outcomes

  1. Proportion of patients achieving complete hematologic rate at week 12

    Evaluate the efficacy of ruxolitinib in improving hematologic remission rates, as measured by International Working Group (IWG) working criteria ET: Platelet count ≤ 400 x 109/L, WBC count \<10 x 109/L, and absence of leukoerythroblastosis PV: hematocrit \<45% and WBC count \<10 x 109/L

    Time frame: Week 12

  2. Proportion of patients achieving complete hematologic rate at 24 Weeks

    Evaluate the efficacy of ruxolitinib in improving hematologic remission rates, as measured by International Working Group (IWG) working criteria ET: Platelet count ≤ 400 x 109/L, WBC count \<10 x 109/L, and absence of leukoerythroblastosis PV: hematocrit \<45% and WBC count \<10 x 109/L

    Time frame: Week 24

  3. Best MPN-SAF TSS score

    Myeloproliferative Neoplasm Symptom Assessment Total Symptom Score (MPN-SAF TSS) for use in major clinical trials and as symptom assessment in all patients in clinical practice. Modeling has established baseline MPN-SAF TSS cut-off scores (total MPN-SAF TSS \>20 or an individual component score \>5) at which symptomatic treatment would be significantly beneficial. Scale title includes absence of symptom (0) and worst imaginable symptoms (10) per question, with minimum score 0 and maximum score 100. Higher scores indicate worse outcomes.

    Time frame: 12 Weeks

  4. Best MPN-SAF TSS score

    Myeloproliferative Neoplasm Symptom Assessment Total Symptom Score (MPN-SAF TSS) for use in major clinical trials and as symptom assessment in all patients in clinical practice. Modeling has established baseline MPN-SAF TSS cut-off scores (total MPN-SAF TSS \>20 or an individual component score \>5) at which symptomatic treatment would be significantly beneficial. . Scale title includes absence of symptom (0) and worst imaginable symptoms (10) per question, with minimum score 0 and maximum score 100. Higher scores indicate worse outcomes.

    Time frame: 24 Weeks

  5. Percentage of change in Spleen Volume

    Spleen volume reduction will be measured as the change in percentage spleen volume from baseline at 12 weeks as measured by CT, or MRI in patients with medical contraindication to CT. Summary statistics will be used to describe changes in spleen volume. Volume will be calculated by a computer-assisted perimeter method based on Sorenson et al. Spleen and liver volume will be obtained by outlining the circumference of the organ and determining the volume using the validated technique of least squares

    Time frame: baseline to 12 weeks

  6. Number of Participants with Treatment Related Adverse Events as Assessed by CTCAE v 5.0

    descriptions and grading scales found in the revised NCI Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 will be utilized for AE reporting

    Time frame: All patients who initiate treatment with study drug up to 60 months

07

Study locations

3 of 4 sites recruiting
08

References and documents

Individual participant data

Plan to share: Yes — The Dana-Farber / Harvard Cancer Center encourages and supports the responsible and ethical sharing of data from clinical trials. De-identified participant data from the final research dataset used in the published manuscript may only be shared under the terms of a Data Use Agreement. Requests may be directed to Sponsor Investigator or designee. The protocol and statistical analysis plan will be made available on Clinicaltrials.gov only as required by federal regulation or as a condition of awards and agreements supporting the research.

Supporting information: Study protocol, Statistical analysis plan, Informed consent form

Time frame: Data can be shared no earlier than 1 year following the date of publication

Access criteria: Contact the Partners Innovations team at http://www.partners.org/innovation

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Mar 2022 (actual). Primary completion is estimated for Jul 2027, 64 months after the start.

Of 27 phase 2 interventional studies under Thrombocythemia, Essential, half reached primary completion within 64 months of starting (the median), counting those still running; a quarter within 32 and three quarters within 141. This study's planned 64 months is close to that.

How these figures are worked out, and which studies are left out of them.

Registered
Nov 10, 2020
First posted
Nov 25, 2020
StartActual
Mar 21, 2022
Primary completionEst.
Jul 2027
CompletionEst.
Jul 2034
Last update
Jan 8, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Jan 8, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04644211
Collaborators
Incyte Corporation
Responsible party
Gabriela Hobbs (Principal Investigator, Massachusetts General Hospital) — Principal investigator
First posted
Nov 25, 2020
Start date
Mar 21, 2022
Primary completion
Jul 2027 (estimated)
Completion
Jul 2034 (estimated)
Last update
Jan 8, 2026

Study contacts

Gabriela Hobbs, MD
Contact
ghobbs@partners.org
(617) 726-8748
Gabriela Hobbs, MD
principal investigator · Massachusetts General Hospital

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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Studies of the drug tested here: Ruxolitinib

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