Aplastic AnemiaNCT04870346
Long Term Follow-up Observational Study After Clinical Trials of AMG531 (Romiplostim) in Patients With Untreated Aplastic Anemia
An observational study of Aplastic Anemia, run by Kyowa Kirin Co., Ltd. at 1 site in Japan.
Trial summary
To evaluate the long-term efficacy and safety after the end of romiplostim treatment by observation [up to 5 years] of patients who were registered for Study 531-003/531-004 in immunosuppressive therapy-naïve patients with aplastic anemia. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Aplastic Anemia
- How many people
- 36 participants
- Where
- 1 siteJapan
- Study dates
- 10 May 2021to 30 Jun 2027
- Phase
- Observational
- 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 Any age
- All sexes
- Child, Adult, Older adult
Study population: Patients enrolled in Study 531-003/531-004
Who may be able to join
- Patients whose written consent to participate in this research was obtained among patients registered for Study 531-003/531-004
- Of the patients who died before their consent to participate in this research was obtained among those registered for Study 531-003/531-004, patients whose legally authorized representatives such as their family had given the consent or patients whose legally authorized representatives had not refused in the disclosure of information by opt-out
- Of the patients who died before their consent to participate in this research was obtained among those registered for Study 531-003/531-004, patients, patients for whom the consent process exemption was approved by the Ethics Review Committee, etc. of the participating medical institutions at the participating medical institutions in the countries without the opt-out system
Who cannot join
- Patients who are judged by the investigator or sub-investigator to be unfavorable for participation in this research
Trial locations and contacts
1 site in 1 country.
Japan1 site
Kanazawa University, College of Medical Pharmaceutical and Health Sciences, School of Medicine, Department of Hematology
Kanazawa, Ishikawa-ken, 920-0934
About this study
To evaluate the long-term efficacy and safety after the end of romiplostim treatment by observation [up to 5 years] of patients who were registered for Study 531-003/531-004 in immunosuppressive therapy-naïve patients with aplastic anemia.
- Conditions
- Aplastic Anemia
- Keywords
- aplastic anemia
- Medical subject headings
- Anemia, Aplastic
What is being measured
The primary outcome is the main question the study is designed to answer.
Hematological response at 2 years after the start of romiplostim treatment in Study 531-003/531-004
Measured: 2 years
Hematological response at up to 5 years after the start of romiplostim treatment in Study 531-003/531-004
Measured: 5 years
Secondary outcomes (1)
The duration of hematological response, and the presence or absence of occurrence of new chromosomal abnormality or transformation to AML/MDS.
- Duration of hematological response in patients who achieved hematologic response at the completion of Study 531-003/531-004
- Time courses of Hb level (g/dL)
- Time courses of platelet count (/μL)
- Time courses of neutrophil count (/μL)
- Presence or absence of platelet blood cell transfusion
- Presence or absence of red blood cell transfusion
- Presence or absence of G-CSF product administration
- Dose level and administration period of cyclosporine A
- Presence or absence of transformation to MDS/AML
- Presence or absence of occurrence of new chromosome abnormality
- Time to the start of subsequent treatment or to death
- Overall survival
Measured: 52, 78, 104, 130, 156, 182, 208, 234, 260 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 May 2021
- Study start10 May 2021
- Primary completion31 Aug 2024
- Study completion30 Jun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Aplastic AnemiaStudies of the same condition, open and under way.
- More trials run by Kyowa Kirin Co., Ltd.The 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 36 participants (actual)
Sponsor and investigators
- Lead sponsor
- Kyowa Kirin Co., Ltd.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Hirohito Yamazaki, Principal investigator, Kanazawa University Hospital, Blood Transfusion Department
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04870346
- Sponsor's protocol ID
- 531-005
- Status last verified
- Oct 2026
- First submitted
- 22 Apr 2021
- Last updated
- 30 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 30 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Long Term Follow-up Observational Study After Clinical Trials of AMG531 (Romiplostim) in Patients With Untreated Aplastic Anemia
- ClinicalTrials.gov ID
- NCT04870346
- Acronym / sponsor ID
- 531-005
- Conditions
- Aplastic Anemia
- Keywords
- aplastic anemia
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 36 participants (actual)
- Lead sponsor
- Kyowa Kirin Co., Ltd.Industry (pharma, biotech, devices)
- Study start
- 10 May 2021 (actual)
- Primary completion
- 31 Aug 2024 (actual)
- Study completion
- 30 Jun 2027 (estimated)
- First posted
- 3 May 2021 (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.
To evaluate the long-term efficacy and safety after the end of romiplostim treatment by observation [up to 5 years] of patients who were registered for Study 531-003/531-004 in immunosuppressive therapy-naïve patients with aplastic anemia.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Sex
- All
- Age groups
- Child, Adult, Older adult
- Study population
- Patients enrolled in Study 531-003/531-004
Key inclusion criteria (3 listed)
- Patients whose written consent to participate in this research was obtained among patients registered for Study 531-003/531-004
- Of the patients who died before their consent to participate in this research was obtained among those registered for Study 531-003/531-004, patients whose legally authorized representatives such as their family had given the consent or patients whose legally authorized representatives had not refused in the disclosure of information by opt-out
- Of the patients who died before their consent to participate in this research was obtained among those registered for Study 531-003/531-004, patients, patients for whom the consent process exemption was approved by the Ethics Review Committee, etc. of the participating medical institutions at the participating medical institutions in the countries without the opt-out system
Key exclusion criteria (1 listed)
- Patients who are judged by the investigator or sub-investigator to be unfavorable for participation in this research
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Hematological response at 2 years after the start of romiplostim treatment in Study 531-003/531-004
Time frame: 2 years
Hematological response at up to 5 years after the start of romiplostim treatment in Study 531-003/531-004
Time frame: 5 years
1 secondary outcome
The duration of hematological response, and the presence or absence of occurrence of new chromosomal abnormality or transformation to AML/MDS.
Time frame: 52, 78, 104, 130, 156, 182, 208, 234, 260 weeks
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 30 Oct 2026.
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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. This study is not recruiting at the moment.
Hirohito Yamazaki principal investigator
Kanazawa University Hospital, Blood Transfusion Department
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Aplastic Anemia, run by Kyowa Kirin Co., Ltd. at 1 site 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 3 inclusion and 1 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: under way, not looking for participants, as of the sponsor's last update on 30 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 1 site 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.
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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Hematological response at 2 years after the start of romiplostim treatment in Study 531-003/531-004 (time frame: 2 years). The study lists 2 primary outcomes in all. 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 30 Oct 2026.