Polycythemia VeraPhase 2NCT07648030
A Study of Rusfertide in Japanese Adults With Polycythemia Vera
A Phase 2 study testing Rusfertide in people with Polycythemia Vera, run by Takeda at 9 sites in Japan.
Trial summary
Polycythemia vera (PV) is a rare blood cancer in which the body makes too many red blood cells. This can make the blood thicker and may increase the risk of serious health problems such as blood clots. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Polycythemia Vera
- What is being tested?
- Rusfertide
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 9 participants
- Where
- 9 sitesJapan
- Study dates
- 14 Jul 2026to 17 May 2030
- Phase
- Phase 2
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Japanese male and female participants aged 18 years or older at the time of signing informed consent.
- Participant understands the trial procedures, is willing and able to adhere to trial requirements and agrees to participate in the trial by giving written informed consent.
- Meet revised 2016 WHO criteria for the diagnosis of PV.
- Phlebotomy requiring defined as ALL of the following:
- At least 3 phlebotomies due to inadequate hematocrit control in 28 weeks before trial intervention or at least 5 phlebotomies due to inadequate hematocrit control in 1 year before trial intervention, and
- Last phlebotomy due to inadequate hematocrit control within 3 months before trial intervention, and
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- No phlebotomy within 6 days prior to trial intervention (do not include day of phlebotomy and day of trial intervention in the 6-day count).
- Note: Phlebotomies performed within an 8-day period will be counted as a single phlebotomy.
- Hematology test values at screening:
- Hematocrit <45%
- WBC 4,000/µL to 20,000/µL (inclusive), and
- Platelets 100,000/µL to 1,000,000/µL (inclusive).
- ECOG performance status 0, 1 or 2.
- WOCBP agree to use at least 1 form of highly effective contraception during the trial and for 30 days after the last dose of trial intervention.
- A female participant must agree not to donate eggs (ova, oocytes) for the purposes of assisted reproduction during the trial and for a period of 30 days after receiving the last dose of trial medication.
- A fertile man agree to use a condom, preferably combined with at least 1 form of acceptable contraception for any WOCBP partner(s) during the trial and for 90 days after the last dose of trial intervention.
- A male participant must agree not to donate sperm for the purpose of reproduction during the trial and for a minimum of 90 days after receiving the last dose.
- Participants receiving CRT at trial intervention must be on a stable PV therapy regimen as follows:
- Hydroxyurea - at least 8 weeks
- JAK inhibitor - at least 8 weeks
- Interferon - at least 24 weeks. Note: A "stable dose regimen" of CRT does not mean an unchanged dose regimen. Temporary adjustments in dose regimen or temporary suspension of dosing are allowed. However, the total weekly dose of hydroxyurea and JAK inhibitor or total monthly dose of interferon may not be higher at trial intervention than the dose at the beginning of the pre-trial intervention observation period. The pre-trial intervention observation period is 8 weeks for hydroxyurea and JAK inhibitor and 24 weeks for interferon.
- Participants treated with phlebotomy alone at trial intervention must have stopped:
- Hydroxyurea at least 8 weeks before trial intervention
- JAK inhibitor at least 8 weeks before trial intervention
- Interferon at least 24 weeks before trial intervention.
Who cannot join
- Clinically meaningful laboratory abnormalities at Screening including, but not limited to:
- eGFR <15 mL/min/1.73 m^2 as determined by Japanese Society of Nephrology. Calculated by the correction formula for Japanese*
- eGFR=194×(serum creatinine value)-1.094×(age)-0.287×(sex correction factor), Sex correction factor: 0.739 in female (Japanese Society of Nephrology,2023).
- ALT or AST ≥2.5×ULN
- Total bilirubin >1.5×ULN. Note: Screening laboratory tests with abnormal results (if considered by the investigator to be transient and inconsistent with the participant's clinical condition) may be repeated within the screening window to confirm abnormal results. If results return to protocol acceptable limits within the screening period, the participant may enter the trial. Use local labs for all eligibility lab tests.
- Participants who require phlebotomy at hematocrit levels lower than 45%.
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- Pregnant females will be ineligible to participate in this trial if, despite a negative pregnancy test, the investigator determines that based on interview, clinical assessment, or other relevant information that the individual may be in the very early stages of pregnancy.
- Is capable of breastfeeding but does not agree to forego breastfeeding from the first dose of trial intervention through 30 days after the last dose of trial intervention.
- Clinically significant thrombosis (eg, deep vein thrombosis or splenic vein thrombosis) within 2 months prior to trial intervention.
- Active or chronic bleeding within 2 months prior to trial intervention.
- Meets the criteria for post-PV myelofibrosis as defined by the International Working Group-Myeloproliferative Neoplasms Research and Treatment (IWG-MRT).
- Any infection requiring systemic therapy within 1 month of dosing except controlled: HIV, hepatitis B, and hepatitis C. Prophylactic therapies are allowed.
- Any serious or unstable medical condition (eg, poorly controlled HIV infection) or uncontrolled psychiatric condition as judged by the investigator that would impair the participant's ability to participate in the trial.
- Major surgical procedure within 2 months prior to trial intervention unless the participant has fully recovered from surgery or planned major elective surgery during the trial.
- History of invasive malignancies within the last 5 years, except
- localized cured cancer (eg, prostate cancer and cervical cancer)
- localized cured in situ or stage 1 squamous cell carcinoma of the skin, basal cell carcinoma of the skin, or in situ melanoma of the skin.
- Participants with in situ or stage 1 squamous cell carcinoma of the skin, in situ or stage 1 basal cell carcinoma of the skin, or in situ melanoma of the skin identified during the required dermatology examination at screening unless the cancer is adequately treated (ie, treatment that is expected to be curative, such as Mohs surgery) before trial intervention. Note: Suspicious lesions should be biopsied and results available before trial intervention.
- Participants with active alcohol or drug addiction that would interfere with their ability to comply with trial requirements.
- Participants who do not complete at least 4 days of MFSAF v4.0 assessments within 1 week prior to trial intervention.
- Receipt of an investigational agent within 2 months or 5 half-lives, whichever is longer, prior to trial intervention.
- Received busulfan within 7 months prior to screening.
- Participants with hypersensitivity to rusfertide or to any of the excipients.
- Participants with any lesion or mass detected by physical examination or imaging during screening that is suspicious for malignancy unless evaluated and assessed to be not malignant.
Trial locations and contacts
9 sites in 1 country. Contact the study team or a site near you to ask about taking part.
9 sites in 1 country
Japan9 sites, 9 recruiting
- Recruiting
Juntendo University Hospital
Bunkyo-ku, Tokyo
- Recruiting
University of Yamanashi Hospital
Chūō, Yamanashi
- Not yet recruiting
Gunma University Hospital
Maebashi, Gunma
- Recruiting
University of Miyazaki Hospital
Miyazaki
- Recruiting
Nagoya Medical Center
Nagoya, Aichi-ken
- Recruiting
Tokyo Medical University Hospital
Shinjuku-ku, Tokyo
- Recruiting
University of Osaka Hospital
Suita, Osaka
- Recruiting
Tokyo Metropilitan Bokutoh Hospital
Sumida-ku, Tokyo
- Recruiting
Mie University Hospital
Tsu, Mie-ken
About this study
Official title: A Phase 2 Open-label Trial to Evaluate the Efficacy and Safety of Rusfertide in Japanese Patients With Polycythemia Vera
Polycythemia vera (PV) is a rare blood cancer in which the body makes too many red blood cells. This can make the blood thicker and may increase the risk of serious health problems such as blood clots. Many people with PV need regular phlebotomy, which is a procedure to remove blood, to help keep their hematocrit level under control. Hematocrit is the proportion of red blood cells in the blood.
The main aim of this study is to evaluate whether rusfertide helps Japanese participants with PV keep their hematocrit under control and avoid the need for phlebotomy. All participants in this study will receive rusfertide. This study is open-label, which means both the participants and the study team will know what treatment is being given.
Participants will be followed for up to about 244 weeks, including a screening period, a 52-week initial treatment period, a long-term extension period, and a 4-week safety follow-up period.
- Conditions
- Polycythemia Vera
- Being tested
- Rusfertide
- Keywords
- Drug Therapy
- Medical subject headings
- Polycythemia Vera
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
RusfertideDrug
Also called TAK-121
Rusfertide injections administered subcutaneously.
| Study group | Role | What they receive |
|---|---|---|
| Rusfertide | Experimental | Participants will receive rusfertide (TAK-121) injections, subcutaneously once a week for 52 weeks (Part 1) followed by 182 weeks long-term extension (Part 2) Receives: Drug: Rusfertide |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of Participants Achieving a Response Starting at Week 20 through Week 32
Response is defined as absence of phlebotomy eligibility. Phlebotomy eligibility is defined as either: A confirmed hematocrit 45% or more and that is at least 3% (absolute) higher than the baseline hematocrit. Confirmation is defined as 2 consecutive hematocrit assessments that are 45% or more and at least 3% higher than the baseline hematocrit (if it is observed at Week 32, confirmation is not required). OR a hematocrit 48% or more.
Measured: Week 20, up to Week 32
Secondary outcomes (9)
Mean Number of Phlebotomies through Week 32
Measured: Baseline, up to Week 32
Percentage of Participants with All Hematocrit Values Less Than 45%
A single hematocrit value >=45% is allowed.
Measured: Baseline, up to Week 32
Median Time to First Hematocrit Value 45% Or More After Enrollment
Measured: Baseline, up to Week 32
Percentage of Participants with At Least One Hematocrit Value 48% Or More
Measured: Baseline, up to Week 32
Percentage of Participants who Maintain Absence of Phlebotomy Eligibility
Measured: Baseline, up to Week 32
Percentage of Participants Achieving Absence of Phlebotomy Eligibility (Durable Response) for 52 Weeks
Measured: Baseline, up to Week 52
Mean Number of Phlebotomies through Week 52
Measured: Baseline, up to Week 52
Median Time to First Hematocrit Value 45% Or More after Week 32 through Week 52
Measured: After Week 32, up to Week 52
Median Time to First Phlebotomy after Week 32 through Week 52
Measured: After Week 32, up to Week 52
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Jun 2026
- Study start14 Jul 2026
- Primary completion28 Oct 2027 (estimated)
- Study completion17 May 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Polycythemia VeraStudies of the same condition, open and under way.
- More trials run by TakedaThe 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 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 9 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Takeda
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Study Director, Study director, Takeda
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07648030
- Sponsor's protocol ID
- TAK-121-2001
- Other IDs
- jRCT2031260215
- Status last verified
- Oct 2026
- First submitted
- 10 Jun 2026
- Last updated
- 2 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: De-identified individual participant data from this particular study will not be shared as there is a reasonable likelihood that individual patients could be reidentified (due to the limited number of study participants/study sites).
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2 Open-label Trial to Evaluate the Efficacy and Safety of Rusfertide in Japanese Patients With Polycythemia Vera
- ClinicalTrials.gov ID
- NCT07648030
- Acronym / sponsor ID
- TAK-121-2001
- Conditions
- Polycythemia Vera
- Keywords
- Drug Therapy
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 9 participants (estimated)
- Lead sponsor
- TakedaIndustry (pharma, biotech, devices)
- Study start
- 14 Jul 2026 (actual)
- Primary completion
- 28 Oct 2027 (estimated)
- Study completion
- 17 May 2030 (estimated)
- First posted
- 15 Jun 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 blood cancer in which the body makes too many red blood cells. This can make the blood thicker and may increase the risk of serious health problems such as blood clots. Many people with PV need regular phlebotomy, which is a procedure to remove blood, to help keep their hematocrit level under control. Hematocrit is the proportion of red blood cells in the blood.
The main aim of this study is to evaluate whether rusfertide helps Japanese participants with PV keep their hematocrit under control and avoid the need for phlebotomy. All participants in this study will receive rusfertide. This study is open-label, which means both the participants and the study team will know what treatment is being given.
Participants will be followed for up to about 244 weeks, including a screening period, a 52-week initial treatment period, a long-term extension period, and a 4-week safety follow-up period.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Rusfertide | Experimental | Drug: RusfertideParticipants will receive rusfertide (TAK-121) injections, subcutaneously once a week for 52 weeks (Part 1) followed by 182 weeks long-term extension (Part 2) |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (25 listed)
- Japanese male and female participants aged 18 years or older at the time of signing informed consent.
- Participant understands the trial procedures, is willing and able to adhere to trial requirements and agrees to participate in the trial by giving written informed consent.
- Meet revised 2016 WHO criteria for the diagnosis of PV.
- Phlebotomy requiring defined as ALL of the following:
- Note: Phlebotomies performed within an 8-day period will be counted as a single phlebotomy.
Key exclusion criteria (24 listed)
- Clinically meaningful laboratory abnormalities at Screening including, but not limited to:
- eGFR=194×(serum creatinine value)-1.094×(age)-0.287×(sex correction factor), Sex correction factor: 0.739 in female (Japanese Society of Nephrology,2023).
- Participants who require phlebotomy at hematocrit levels lower than 45%.
- Pregnant females will be ineligible to participate in this trial if, despite a negative pregnancy test, the investigator determines that based on interview, clinical assessment, or other relevant information that the individual may be in the very early stages of pregnancy.
- Is capable of breastfeeding but does not agree to forego breastfeeding from the first dose of trial intervention through 30 days after the last dose of trial intervention.
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 |
|---|---|---|
| RusfertideAlso: TAK-121Rusfertide injections administered subcutaneously. | Drug | Rusfertide |
Primary outcome
Percentage of Participants Achieving a Response Starting at Week 20 through Week 32
Time frame: Week 20, up to Week 32
Response is defined as absence of phlebotomy eligibility. Phlebotomy eligibility is defined as either: A confirmed hematocrit 45% or more and that is at least 3% (absolute) higher than the baseline hematocrit. Confirmation is defined as 2 consecutive hematocrit assessments that are 45% or more and at least 3% higher than the baseline hematocrit (if it is observed at Week 32, confirmation is not required). OR a hematocrit 48% or more.
9 secondary outcomes
Mean Number of Phlebotomies through Week 32
Time frame: Baseline, up to Week 32
Percentage of Participants with All Hematocrit Values Less Than 45%
Time frame: Baseline, up to Week 32
Median Time to First Hematocrit Value 45% Or More After Enrollment
Time frame: Baseline, up to Week 32
Percentage of Participants with At Least One Hematocrit Value 48% Or More
Time frame: Baseline, up to Week 32
Percentage of Participants who Maintain Absence of Phlebotomy Eligibility
Time frame: Baseline, up to Week 32
Percentage of Participants Achieving Absence of Phlebotomy Eligibility (Durable Response) for 52 Weeks
Time frame: Baseline, up to Week 52
Mean Number of Phlebotomies through Week 52
Time frame: Baseline, up to Week 52
Median Time to First Hematocrit Value 45% Or More after Week 32 through Week 52
Time frame: After Week 32, up to Week 52
Median Time to First Phlebotomy after Week 32 through Week 52
Time frame: After Week 32, up to Week 52
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 2 Oct 2026.
- Click here to ask Takeda's chatbot for comprehensive and easy-to-understand information about clinical trials - even across products and indications - in your local language.Link provided by the sponsor.
- Click here for more information about this trial in easy-to-understand language, including a Plain Language Summary of the results if the trial has been completed.Link provided by the sponsor.
- Individual participant dataSharing planned: No. De-identified individual participant data from this particular study will not be shared as there is a reasonable likelihood that individual patients could be reidentified (due to the limited number of study participants/study sites).
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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.
Study Director study director
Takeda
9 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Rusfertide in people with Polycythemia Vera, run by Takeda at 9 sites in Japan.
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 25 inclusion and 24 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: looking for participants now, as of the sponsor's last update on 2 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 9 sites in Japan. 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.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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 Takeda Contact (+1-877-825-3327, medinfoUS@takeda.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percentage of Participants Achieving a Response Starting at Week 20 through Week 32 (time frame: Week 20, up to Week 32). 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 2 Oct 2026.