Thrombotic MicroangiopathyALX-TMA-502NCT07732361
A Study Using Real-world Data to Examine Outcomes in Children and Adults Who Develop a Blood Clotting Disorder Called Thrombotic Microangiopathy (TMA) After Undergoing a Hematopoietic Stem Cell Transplant (HSCT).
An observational study of Thrombotic Microangiopathy and Hematopoietic Stem Cell Transplant, run by Alexion Pharmaceuticals, Inc. at 43 sites in 10 countries.
Trial summary
The purpose of this study was to assess OS outcomes in pediatric (≥ 28 days of age at the time of HSCT-TMA diagnosis) and adult participants diagnosed with HSCT-TMA(referred to as TMA from hereon) within 52 weeks after HSCT and who were either complement inhibitor treatment naïve or had been treated with eculizumab. Read more about this study
- Who is it for?
- Ages 4 weeks and older
- Conditions the study is for
- Thrombotic Microangiopathy, Hematopoietic Stem Cell Transplant
- How many people
- 307 participants
- Where
- 43 sitesin 10 countries
- Study dates
- 22 Jan 2025to 31 Mar 2026
- Phase
- Observational
- Are there results?
- None posted in the registry
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 4 weeks and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: The study included pediatric and adult participants who were diagnosed with TMA within 52 weeks after an HSCT procedure and who were either complement inhibitor treatment naïve or had been treated with eculizumab. Data was collected from medical records in 41 study centers across 10 countries
Who may be able to join
- Participant must be ≥ 28 days of age at the time of TMA diagnosis.
- Body weight ≥ 5 kg at the time of TMA diagnosis.
- Documented TMA on/after 01 Jan 2010 to 30 Jun 2024 with concurrent renal dysfunction with no documented alternative explanation ≤ 52 weeks from the HSCT.
- Documentation of participant's vital status through 52 weeks after the date of TMA diagnosis.
- Documentation of date and type of HSCT, date of TMA, absence of acute GVHD, and infection status at time of TMA diagnosis.
- Documentation of at least 2 of the following: indication for most recent HSCT, serum creatinine at time of TMA diagnosis, presence of multiorgan dysfunction at time of TMA diagnosis.
- Informed consent obtained if required by local regulations.
Who cannot join
- Medical Conditions (Ongoing at the Time of TMA Diagnosis): TTP, ST-HUS, Immune-mediated hemolysis not due to TMA, DIC, Bone marrow/graft failure of HSCT, VOD (regardless of severity), HIV infection, Sepsis that required vasopressor support.
- Prior/Concomitant Therapy: Received a complement inhibitor other than eculizumab from time of suspicion of HSCT-TMA diagnosis through 52 weeks post-HSCT-TMA diagnosis..
- Other Exclusions: Participation in an investigational drug or device study for the treatment of TMA within 30 days prior to TMA diagnosis or during the 52 weeks following TMA diagnosis.
Trial locations and contacts
43 sites in 10 countries.
43 sites in 10 countries
Brazil11 sites
Research Facility
Brasília, Federal District, 70684-831
Research Facility
Curitiba, Paraná, 80060-900
Research Facility
Fortaleza, Ceará, 60430-372
Research Facility
Jaú, São Paulo, 17210-120
Research Facility
Porto Alegre, Rio Grande do Sul, 90035-903
Research Facility
Recife, Pernambuco, 52010-010
Research Facility
Rio de Janeiro, 20230-130
Research Facility
São Paulo, 04023-064
Research Facility
São Paulo, 05403-000
Research Facility
São Paulo, 05410-030
Research Facility
São Paulo, 15090-000
Italy9 sites
Research Facility
Ancona, 60126
Research Facility
Brescia, 25123
Research Facility
Florence, 50134
Research Facility
Genova, 16147
Research Facility
Naples, 80123
Research Facility
Pavia, 27100
Research Facility
Roma, 00165
Research Facility
Rome, Lazio, 00168
Research Facility
Torino, 10126
France4 sites
Research Facility
Grenoble, Isere, 38043
Research Facility
Paris, 75475
Research Facility
Pessac, Gironde, 33604
Research Facility
Toulouse, Haute Garonne, 31059
Japan4 sites
Research Facility
Fukushima, Fukushima, 960-1295
Research Facility
Saitama-shi, Saitama, 330-8777
Research Facility
Tsukuba, Ibaraki, 305-8576
Research Facility
Wakayama, Wakayama, 641-8510
United States3 sites
Research Facility
Akron, Ohio, 44308
Research Facility
Boston, Massachusetts, 02215
Research Facility
Salt Lake City, Utah, 84108
South Korea3 sites
Research Facility
Seoul, 03080
Research Facility
Seoul, 05505
Research Facility
Seoul, 06351
United Kingdom3 sites
Research Facility
Birmingham, West Midlands, B4 6NH
Research Facility
London, Greater London, W12 0HS
Research Facility
Newcastle, Tyne & Wear, NE1 4LP
Belgium2 sites
Research Facility
Brussels, Brussels Capital, 1020
Research Facility
Liège, 1020
Greece2 sites
Research Facility
Pátrai, West Greece, 26500
Research Facility
Thessaloniki, Central Macedonia, 57010
Spain2 sites
Research Facility
Barcelona, 08041
Research Facility
Barcelona, 08950
About this study
Official title: A Secondary Real-world Data Study of Pediatric and Adult Participants With Thrombotic Microangiopathy (TMA) After Hematopoietic Stem Cell Transplant (HSCT)
The purpose of this study was to assess OS outcomes in pediatric (≥ 28 days of age at the time of HSCT-TMA diagnosis) and adult participants diagnosed with HSCT-TMA(referred to as TMA from hereon) within 52 weeks after HSCT and who were either complement inhibitor treatment naïve or had been treated with eculizumab.
- Keywords
- Thrombotic Microangiopathy, TMA, Hematopoietic Stem Cell Transplant, HSCT, Observational Study, Real-world Data, Retrospective
- Medical subject headings
- Thrombotic Microangiopathies
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| TMA after HSCT pediatric participants, complement inhibitor treatment naïve | The study included pediatric participants who were diagnosed with TMA within 52 weeks after an HSCT procedure and who were complement inhibitor treatment naïve | |
| TMA after HSCT pediatric participants who had been treated with eculizumab | The study included pediatric participants who were diagnosed with TMA within 52 weeks after an HSCT procedure and who had been treated with eculizumab | |
| TMA after HSCT adult participants, complement inhibitor treatment naïve | The study included adult participants who were diagnosed with TMA within 52 weeks after an HSCT procedure and who were complement inhibitor treatment naïve | |
| TMA after HSCT adult participants who had been treated with eculizumab | The study included adult participants who were diagnosed with TMA within 52 weeks after an HSCT procedure and who had been treated with eculizumab |
What is being measured
The primary outcome is the main question the study is designed to answer.
Overall Survival (OS)
To assess OS through 52 weeks after TMA diagnosis.
Measured: 52 weeks after TMA diagnosis
Secondary outcomes (2)
Overall Survival (OS)
OS through 100 days and 26 weeks after TMA diagnosis.
Measured: 100 days and 26 weeks after TMA diagnosis
Non-relapse mortality
Non-relapse mortality, defined as death due to any cause other than primary disease progression (i.e. indication fror transplant) or relapse.
Measured: Through 100 days, 26 weeks, and 52 weeks after TMA diagnosis
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jul 2026
- Study start22 Jan 2025
- Primary completion31 Mar 2026
- Study completion31 Mar 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Thrombotic MicroangiopathyStudies of the same condition, open and under way.
- More trials run by Alexion Pharmaceuticals, Inc.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
- Retrospective
- Enrolment
- 307 participants (actual)
Sponsor and investigators
- Lead sponsor
- Alexion Pharmaceuticals, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07732361
- Sponsor's protocol ID
- D9284C00003
- Other IDs
- ALX-TMA-502, D9284C00003
- Acronym
- ALX-TMA-502
- Status last verified
- Jul 2026
- First submitted
- 23 Jul 2026
- Last updated
- 28 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Alexion has a public commitment to allow requests for access to study data and will be supplying a protocol, CSR, and plain language summaries.
Study at a glance
From the registry record, last updated by the sponsor on 28 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Secondary Real-world Data Study of Pediatric and Adult Participants With Thrombotic Microangiopathy (TMA) After Hematopoietic Stem Cell Transplant (HSCT)
- ClinicalTrials.gov ID
- NCT07732361
- Acronym / sponsor ID
- ALX-TMA-502 / D9284C00003
- Keywords
- Thrombotic Microangiopathy, TMA, Hematopoietic Stem Cell Transplant, HSCT, Observational Study, Real-world Data, Retrospective
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 307 participants (actual)
- Lead sponsor
- Alexion Pharmaceuticals, Inc.Industry (pharma, biotech, devices)
- Study start
- 22 Jan 2025 (actual)
- Primary completion
- 31 Mar 2026 (actual)
- Study completion
- 31 Mar 2026 (actual)
- First posted
- 28 Jul 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.
The purpose of this study was to assess OS outcomes in pediatric (≥ 28 days of age at the time of HSCT-TMA diagnosis) and adult participants diagnosed with HSCT-TMA(referred to as TMA from hereon) within 52 weeks after HSCT and who were either complement inhibitor treatment naïve or had been treated with eculizumab.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| TMA after HSCT pediatric participants, complement inhibitor treatment naïve | – | –The study included pediatric participants who were diagnosed with TMA within 52 weeks after an HSCT procedure and who were complement inhibitor treatment naïve |
| TMA after HSCT pediatric participants who had been treated with eculizumab | – | –The study included pediatric participants who were diagnosed with TMA within 52 weeks after an HSCT procedure and who had been treated with eculizumab |
| TMA after HSCT adult participants, complement inhibitor treatment naïve | – | –The study included adult participants who were diagnosed with TMA within 52 weeks after an HSCT procedure and who were complement inhibitor treatment naïve |
| TMA after HSCT adult participants who had been treated with eculizumab | – | –The study included adult participants who were diagnosed with TMA within 52 weeks after an HSCT procedure and who had been treated with eculizumab |
Who may qualify
- Ages
- 4 weeks and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- The study included pediatric and adult participants who were diagnosed with TMA within 52 weeks after an HSCT procedure and who were either complement inhibitor treatment naïve or had been treated with eculizumab. Data was collected from medical records in 41 study centers across 10 countries
Key inclusion criteria (7 listed)
- Participant must be ≥ 28 days of age at the time of TMA diagnosis.
- Body weight ≥ 5 kg at the time of TMA diagnosis.
- Documented TMA on/after 01 Jan 2010 to 30 Jun 2024 with concurrent renal dysfunction with no documented alternative explanation ≤ 52 weeks from the HSCT.
- Documentation of participant's vital status through 52 weeks after the date of TMA diagnosis.
- Documentation of date and type of HSCT, date of TMA, absence of acute GVHD, and infection status at time of TMA diagnosis.
Key exclusion criteria (3 listed)
- Medical Conditions (Ongoing at the Time of TMA Diagnosis): TTP, ST-HUS, Immune-mediated hemolysis not due to TMA, DIC, Bone marrow/graft failure of HSCT, VOD (regardless of severity), HIV infection, Sepsis that required vasopressor support.
- Prior/Concomitant Therapy: Received a complement inhibitor other than eculizumab from time of suspicion of HSCT-TMA diagnosis through 52 weeks post-HSCT-TMA diagnosis..
- Other Exclusions: Participation in an investigational drug or device study for the treatment of TMA within 30 days prior to TMA diagnosis or during the 52 weeks following TMA diagnosis.
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
Overall Survival (OS)
Time frame: 52 weeks after TMA diagnosis
To assess OS through 52 weeks after TMA diagnosis.
2 secondary outcomes
Overall Survival (OS)
Time frame: 100 days and 26 weeks after TMA diagnosis
Non-relapse mortality
Time frame: Through 100 days, 26 weeks, and 52 weeks after TMA diagnosis
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Jul 2026.
- Individual participant dataSharing planned: Yes. Alexion has a public commitment to allow requests for access to study data and will be supplying a protocol, CSR, and plain language summaries.
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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.
The record lists no contact. Use the official record to reach the sponsor.
43 sites in 10 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Thrombotic Microangiopathy and Hematopoietic Stem Cell Transplant, run by Alexion Pharmaceuticals, Inc. at 43 sites in 10 countries.
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 7 inclusion and 3 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: finished, as of the sponsor's last update on 28 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 43 sites in Brazil, Italy, France, Japan, United States and 5 more countries. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Overall Survival (OS) (time frame: 52 weeks after TMA diagnosis). 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 28 Jul 2026.