PolycythemiaACTIVAQNCT07341048
Potential Biological and Physiological Determinants for Exercice in Patients With Polycythemia Vera
A study testing Research samples blood viscosity and viscoelasticity: in people with Polycythemia and Polycythemia Vera (PV), run by Hospices Civils de Lyon at 1 site in France.
Trial summary
Polycythemia vera (PV) is a rare haematological disorder characterized by an excessive production of red blood cells, associated with the somatic JAK2 V617F mutation. Clinical manifestations are varied and often include exercise intolerance but the underlying mechanisms remain poorly understood. Read more about this study
- Who is it for?
- Ages 18 to 70 years
- Conditions the study is for
- Polycythemia, Polycythemia Vera (PV)
- What is being tested?
- Research samples blood viscosity and viscoelasticity:
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 54 participants
- Where
- 1 siteFrance
- Study dates
- Jan 2026to May 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patient aged at least 18 years and under 70.
- Patient followed for a diagnosis of Polycytemia vera (confirmed JAK2 V617F mutation) and who were prescribed a CPET because of their wish to resume regular physical activity.
- Patient affiliated with or benefiting from a social security scheme.
Who cannot join
- Any known history of heart disease or chronic respiratory illness likely to affect VO₂max independently of Polycytemia vera (e.g., asthma), according to the investigator's judgment.
- Any known history of major thromboembolic complication, according to the investigator's judgment.
- Body mass index (BMI) greater than 35, according to the investigator's judgment.
- Participation in another interventional research protocol that may interfere with the present study, according to the investigator's judgment.
- Adult subject under legal protection measures (guardianship, curatorship).
- Subject currently receiving psychiatric care.
- Subject deprived of liberty by judicial or administrative decision.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site
Department of Sports Medicine and Physical Activity. Pulmonary Function Testing. Croix Rousse Hospital.
Lyon, 69001
Emeric Stauffer, Dr, +33 (0)4 72 07 18 62, emeric.stauffer@chu-lyon.fr
Marie Ducray, Phd, marie.ducray@univ-lyon1.fr
About this study
Official title: Characterization of Exercise Intolerance in Patients With Polycythemia Vera: Study of Potential Biological and Physiological Determinants.
Polycythemia vera (PV) is a rare haematological disorder characterized by an excessive production of red blood cells, associated with the somatic JAK2 V617F mutation. Clinical manifestations are varied and often include exercise intolerance but the underlying mechanisms remain poorly understood.
Physical activity is recommended in the management of chronic diseases, but it must be tailored to the physiological profile of the patient. A cardiopulmonary exercise test (CPET) is essential to ensure safety, detect possible contraindications, and assess maximal oxygen uptake (VO₂max), a key indicator of aerobic performance.
Read more
This prospective, experimental, non-randomized study will include patients with PV followed at Lyon Sud University Hospital and for which a CPET is scheduled in their routine clinical follow-up. The primary objective is to compare VO₂max between two groups of patients: moderate (<10%) versus marked (≥10%) extent of blood viscosity increase after the completion of the CPET. The main hypothesis is that a significant increase in blood viscosity during exercise (≥10%) is a major limiting factor in oxygen transport and leads to a reduced VO₂max, reflecting impaired exercise tolerance.
Secondary analyses will focus on hemorheological parameters, tissue oxygenation, and cardiorespiratory and metabolic responses. The study aims to better understand the biological and physiological determinants of exercise intolerance in this population.
- Conditions
- Polycythemia, Polycythemia Vera (PV)
- Being tested
- Research samples blood viscosity and viscoelasticity:
- Keywords
- Blood viscosity, polycythemia
- Medical subject headings
- Polycythemia, Polycythemia Vera
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Research samples blood viscosity and viscoelasticity:Biological
Also called the level of tissue oxygenation and hemoglobin oxygenation that will be measured by near-infrared spectroscopy (NIRS).
Research samples: Blood rheology: hematocrit, blood viscosity, deformability and erythrocyte aggregation, viscoelasticity
| Study group | Role | What they receive |
|---|---|---|
| Polycythemia vera | Experimental | Patients diagnosed with polycythemia vera, with confirmed presence of the JAK2 V617F mutation, who wish to resume regular daily physical activity and have been prescribed an exercise test for this purpose as part of their follow-up at Lyon Sud Hospital Receives: Biological: Research samples blood viscosity and viscoelasticity: |
What is being measured
The primary outcome is the main question the study is designed to answer.
Blood viscosity (Centipoise) at 6 shear rates.
Blood viscosity will be measured using a cone-plate viscometer (Brookfield, model LVDVII+ PRO, cone CPE 40) on native hematocrit blood, at 7 different shear rates: 2.25, 4.5, 11.5, 22.5, 45, 90, and 225 s-¹, using an ascending ramp shear protocol.
Measured: Measurements will be performed at baseline (pre-test), at 3 minutes post-CPET, and at 60 minutes post-CPET
Secondary outcomes (3)
Rheological properties of blood: deformability and aggregation of erythrocytes
Analyses will be performed on EDTA tubes. Erythrocyte deformability will be measured by ektacytometry at 9 shear stresses (0.3-30 Pa) under isotonic conditions. Maximal elongation index (EImax) and shear stress for 50% deformation (SS₁/₂) will be recorded. Aggregation/disaggregation will be assessed by syllectometry at 40% hematocrit. Parameters include aggregation index (AI) and minimal shear rate (γmin) for full disaggregation
Measured: Measurements will be performed at baseline (pre-test), at 3 minutes post-CPET, and at 60 minutes post-CPET.
Viscoelasticity of blood
Viscoelastic properties of blood will be assessed using rotational thromboelastometry (ROTEM delta) on citrated blood tubes. The following tests will be performed: NATEM, TEMACT, FIBTEM, and EXTEM. For each test, the following parameters will be measured: clotting time (CT, in seconds), clot amplitude at 5, 10, 20, and 30 minutes (A5, A10, A20, A30, in mm), alpha angle (indicating clot formation velocity, in degrees), maximum clot firmness (in mm), percentage of clot lysis at 30 minutes (LI30), as well as lysis onset time (LOT) and total lysis time (LT), both expressed in seconds
Measured: Measurements will be performed at baseline (pre-test), at 3 minutes post-CPET, and at 60 minutes post-CPET
Tissue and haemoglobin oxygenation with near-infrared spectroscopy (NIRS)
Near-infrared spectroscopy (NIRS) will be performed using the Portamon MKIII system (Artinis) with a sampling rate of 100 Hz. This non-invasive technique involves placing surface electrodes on the skin over the vastus lateralis muscle, halfway between the anterior superior iliac spine and the patella. NIRS enables continuous monitoring of changes in oxyhemoglobin (HbO₂) and deoxyhemoglobin (HHb) concentrations, allowing for the calculation of the tissue oxygenation index (TOI)
Measured: Measurement will be performed during the CPET.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Jan 2026
- Study startJan 2026 (estimated)
- Primary completionMay 2027 (estimated)
- Study completionMay 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PolycythemiaStudies of the same condition, open and under way.
- More trials run by Hospices Civils de LyonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Prospective, experimental, single-center, non-randomized study.
- Masking
- None (open label)
- Enrolment
- 54 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hospices Civils de Lyon
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07341048
- Sponsor's protocol ID
- 69HCL25_0364
- Other IDs
- 2025-A01032-47
- Acronym
- ACTIVAQ
- Status last verified
- Jan 2026
- First submitted
- 5 Jan 2026
- Last updated
- 15 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Characterization of Exercise Intolerance in Patients With Polycythemia Vera: Study of Potential Biological and Physiological Determinants.
- ClinicalTrials.gov ID
- NCT07341048
- Acronym / sponsor ID
- ACTIVAQ / 69HCL25_0364
- Conditions
- Polycythemia, Polycythemia Vera (PV)
- Keywords
- Blood viscosity, polycythemia
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 54 participants (estimated)
- Lead sponsor
- Hospices Civils de LyonUniversity, hospital or other
- Study start
- Jan 2026 (estimated)
- Primary completion
- May 2027 (estimated)
- Study completion
- May 2027 (estimated)
- First posted
- 14 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Polycythemia vera (PV) is a rare haematological disorder characterized by an excessive production of red blood cells, associated with the somatic JAK2 V617F mutation. Clinical manifestations are varied and often include exercise intolerance but the underlying mechanisms remain poorly understood.
Physical activity is recommended in the management of chronic diseases, but it must be tailored to the physiological profile of the patient. A cardiopulmonary exercise test (CPET) is essential to ensure safety, detect possible contraindications, and assess maximal oxygen uptake (VO₂max), a key indicator of aerobic performance.
This prospective, experimental, non-randomized study will include patients with PV followed at Lyon Sud University Hospital and for which a CPET is scheduled in their routine clinical follow-up. The primary objective is to compare VO₂max between two groups of patients: moderate (<10%) versus marked (≥10%) extent of blood viscosity increase after the completion of the CPET. The main hypothesis is that a significant increase in blood viscosity during exercise (≥10%) is a major limiting factor in oxygen transport and leads to a reduced VO₂max, reflecting impaired exercise tolerance.
Secondary analyses will focus on hemorheological parameters, tissue oxygenation, and cardiorespiratory and metabolic responses. The study aims to better understand the biological and physiological determinants of exercise intolerance in this population.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Prospective, experimental, single-center, non-randomized study.
| Arm | Type | Receives |
|---|---|---|
| Polycythemia vera | Experimental | Biological: Research samples blood viscosity and viscoelasticity:Patients diagnosed with polycythemia vera, with confirmed presence of the JAK2 V617F mutation, who wish to resume regular daily physical activity and have been prescribed an exercise test for this purpose as part of their follow-up at Lyon Sud Hospital |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Patient aged at least 18 years and under 70.
- Patient followed for a diagnosis of Polycytemia vera (confirmed JAK2 V617F mutation) and who were prescribed a CPET because of their wish to resume regular physical activity.
- Patient affiliated with or benefiting from a social security scheme.
Key exclusion criteria (7 listed)
- Any known history of heart disease or chronic respiratory illness likely to affect VO₂max independently of Polycytemia vera (e.g., asthma), according to the investigator's judgment.
- Any known history of major thromboembolic complication, according to the investigator's judgment.
- Body mass index (BMI) greater than 35, according to the investigator's judgment.
- Participation in another interventional research protocol that may interfere with the present study, according to the investigator's judgment.
- Adult subject under legal protection measures (guardianship, curatorship).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Research samples blood viscosity and viscoelasticity:Also: the level of tissue oxygenation and hemoglobin oxygenation that will be measured by near-infrared spectroscopy (NIRS).Research samples: Blood rheology: hematocrit, blood viscosity, deformability and erythrocyte aggregation, viscoelasticity | Biological | Polycythemia vera |
Primary outcome
Blood viscosity (Centipoise) at 6 shear rates.
Time frame: Measurements will be performed at baseline (pre-test), at 3 minutes post-CPET, and at 60 minutes post-CPET
Blood viscosity will be measured using a cone-plate viscometer (Brookfield, model LVDVII+ PRO, cone CPE 40) on native hematocrit blood, at 7 different shear rates: 2.25, 4.5, 11.5, 22.5, 45, 90, and 225 s-¹, using an ascending ramp shear protocol.
3 secondary outcomes
Rheological properties of blood: deformability and aggregation of erythrocytes
Time frame: Measurements will be performed at baseline (pre-test), at 3 minutes post-CPET, and at 60 minutes post-CPET.
Viscoelasticity of blood
Time frame: Measurements will be performed at baseline (pre-test), at 3 minutes post-CPET, and at 60 minutes post-CPET
Tissue and haemoglobin oxygenation with near-infrared spectroscopy (NIRS)
Time frame: Measurement will be performed during the CPET.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Jan 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Research samples blood viscosity and viscoelasticity: in people with Polycythemia and Polycythemia Vera (PV), run by Hospices Civils de Lyon at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 15 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Emeric Stauffer, Dr (+33 (0)4 72 07 18 62, emeric.stauffer@chu-lyon.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Blood viscosity (Centipoise) at 6 shear rates. (time frame: Measurements will be performed at baseline (pre-test), at 3 minutes post-CPET, and at 60 minutes post-CPET). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Jan 2026.