Recovery and survival of stem cell originated red cells

ISRCTN ISRCTN42886452
DOI https://doi.org/10.1186/ISRCTN42886452
EudraCT/CTIS number 2017-002178-38
IRAS number 229563
Secondary identifying numbers CPMS: 39643; IRAS: 229563
Submission date
03/09/2018
Registration date
04/07/2019
Last edited
01/04/2025
Recruitment status
No longer recruiting
Overall study status
Ongoing
Condition category
Other
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English Summary

Background and study aims
About 1.5 million red blood cell (RBC) donations are collected by NHS Blood and Transplant and transfused each year, but there are a small number of patients with rare blood group types for whom NHS Blood and Transplant cannot meet the transfusion requirements. New RBCs can be grown from human blood stem cells in the laboratory (manufactured red blood cells, mRBCs). It is hoped that this will provide a novel transfusion product for these patients in the future, some of whom require regular transfusions throughout life (e.g. for thalassemia or sickle cell disease). Researchers want to find out whether mRBCs are safe and last longer in the circulation in the body than standard donated RBCs (sRBCs). The mRBCs are all young whereas in standard donated blood the RBCs will be of varying ages, from young cells to those that are reaching the end of their life span. Studies have shown that younger RBCs stay in the circulation for longer once they have been transfused. If the mRBCs last longer than the sRBCs this could mean that such cells could eventually reduce how often transfusions are needed in patients who are dependent on transfusions.

Who can participate?
This study is a Phase 1 Trial in healthy volunteers with a unique recruitment process that requires pre-study matching for several blood groups and therefore is not open to the public domain.

What does the study involve?
The participants that are recruited will be given the information at the time of recruitment.

What are the possible benefits and risks of participating?
The participants that are recruited will be given the information at the time of recruitment.

Where is the study run from?
This trial is being managed by NHS Blood and Transplant Clinical Trials Unit in Cambridge (UK)

When is the study starting and how long is it expected to run for?
August 2018 to October 2025

Who is funding the study?
NHS Blood and Transplant and the National Institute of Health Research (NIHR) (UK)

Who is the main contact?
Restore.trial@nhsbt.nhs.uk
Viona Rundell (viona.rundell@nhsbt.nhs.uk)
Claire Rourke (claire.rourke2@nhsbt.nhs.uk).

Study website

Contact information

Ms Viona Rundell
Public

NHSBT Clinical Trials Unit
Cambridge Blood Donor Centre
Long Road
Cambridge
CB2 0PT
United Kingdom

Phone +44 (0)7385 530070
Email viona.rundell@nhsbt.nhs.uk
Ms Claire Rourke
Scientific

NHSBT Clinical Trials Unit
Cambridge Blood Donor Centre
Long Road
Cambridge
CB2 0PT
United Kingdom

ORCiD logoORCID ID 0000-0002-7631-9275
Phone +44 (0)7385 964361
Email claire.rourke2@nhsbt.nhs.uk

Study information

Study designRandomized; Interventional; Design type: Treatment, Drug, Other
Primary study designInterventional
Secondary study designRandomised cross over trial
Study setting(s)Hospital
Study typeTreatment
Participant information sheet Not available in web format, please use the contact details to request a patient information sheet
Scientific titleA single centre, randomised, controlled, single-blind Phase I cross-over trial in healthy volunteers to assess the safety and survival of a mini-dose of red blood cells derived from CD34+ cells isolated from adult blood vs standard donated red blood cells
Study acronymRESTORE
Study hypothesisManufactured red blood cells (RBC) will have a longer survival in the circulation of the volunteers than the standard donated RBC.
Ethics approval(s)Approved 06/11/2018, London-West London and GTAC Research Ethics Committee (Hammersmith Hospital, London, W12 0NN, UK; Tel: +44 (0)207 104 8007; Email: NRESCommittee.London-WestLondon@nhs.net), ref: 18/LO/1494
ConditionBlood transfusion
InterventionSetting:
1. Units of whole blood will be donated in the East Anglian region static or mobile donor clinics/sessions
2. Red cells will be produced from whole blood donations in licensed facilities at NHSBT Bristol (Filton)
3. Red cells will be radiolabelled with 51Cr in the Radiopharmacy Unit, Guy's Hospital, London
4. Recipients will receive infusions of radiolabelled RBCs in the Wellcome Trust/NIHR Clinical Research Facility at Addenbrooke’s Hospital, and follow up blood samples will be taken at their home or place of work, according to their preference

Interventions to be compared:
Red blood cells manufactured from adult haematopoietic stem cells (mRBC)
Comparator: standard donated red blood cells (sRBC)

Selection of participants:
Potential donor participants born after 1st January 1996 with an extended blood group phenotype available were identified anonymously.
Potential recipients were sought from the Cambridge Bioresource (CBR) as part of the RESTORE-i feasibility trial. Potentially eligible members of the CBR were approached by the CBR team for their permission for the RESTORE study team to contact them to discuss their participation in this clinical trial.
To be potentially eligible for the trial, donors and recipients must be willing to participate, and also be blood group compatible with potential recipients or donors.
Once the panel of blood compatible Donors and Recipients has been identified as part of the RESTORE-i feasibility, groups of blood phenotype matched donors and recipients will be selected, with donors with the highest CD34+ (haematopoietic stem cell) counts selected as a preference. Each group will consist of a minimum of 1 donor and 2 recipients to ensure availability of recipients for the mRBC and avoid wastage.

Screening & consent
1) Donor Consent Visit (day -35 prior to the study intervention):
Donors will be sent a detailed information sheet and be given a minimum of 48 hours to decide if they are interested in participating, and if so a consent visit will be arranged with the study nurse. At the consent visit, the CI or delegated physician will explain in detail the exact nature, purpose, risks, requirements, implications and constraints of the study supported by written information. Donors will be given the opportunity to ask any questions they may have about the trial. If they agree, they will be asked to provide full written informed consent.

A whole blood sample is taken for standard screening for: sickle cell trait, pseudohyperkalaemia, G6PD deficiency, confirmation of blood group phenotype, virology (Hepatitis B, Hepatitis C, HIV), FBC/ferritin. A flag will also be placed on the NHSBT systems to prevent the Donor from being called for routine blood donations.

2) Recipient consent & screening visit:
At the consent visit, if potential recipients agree to participate in the trial and the study nurse has re-confirmed their eligibility, they will be asked to provide written informed consent. Blood samples will also be taken to carry out cross-matches with the sRBC and mRBC prior to the infusions.
In the month prior to the study the potential recipient will undergo baseline medical investigations which will comprise:
I) Medical history (allergies, previous/planned surgery, ongoing investigations, heart disease, diabetes, gastrointestinal disease, respiratory disease, neurological problems, systemic illness, chronic infection, skin disorders, musculoskeletal disease, other illness, radioisotope exposure in the last 12 months)
II) Physical examination (BP, pulse, temperature, cardiovascular, respiratory, abdomen, CNS/PNS)
III) Clinical laboratory tests including full blood count, biochemistry and virology

The CI or delegate will review pre-study data to ascertain the potential recipient’s continued eligibility for the trial which will be documented accordingly.
Once the study team is satisfied that the potential recipient is eligible following the additional screening tests, he or she will be allocated to a donor-recipient group Randomisation will be at the level of the donor-recipient group to which the individual is assigned.

Randomisation
It is envisaged that in total ten groups will be assigned to the intervention, n=5 will receive the standard red cells first, n=5 will receive the mRBC first. The randomisation will determine whether the recipients in a given group receive standard red cells or manufactured red cells first, to be followed by the alternate type of red cell, except that the recipients from the first 2 groups that go through the study will receive standard red cells first. The total number of recipients receiving standard red cells will be at least 15 of which only 10 recipients will go on to receive the mRBC.

Groups will be randomised by the independent statistician, determining which type of red cells will be received first for that group. The randomisation will also allocate each recipient an order within their group, to indicate which of the recipients should preferentially be transfused. In particular, this order will indicate which of the two recipients who received standard cells first should go on to receive manufactured red cells. In groups with more than one donor, donors will be ordered by descending CD34 count.

Study procedures:
1) Donors
Following screening, the blood donor will be called for a whole blood donation visit at a mutually agreed time. The donor will be required to meet all criteria for donation of blood for transfusion according to NHS Blood & Transplant Guidelines whereby they will donate one unit of whole blood. This unit of whole blood will be processed as follows:
- under GMP conditions in a licensed Blood Establishment into standard red cells (control arm) or
- by the Advanced Therapies Unit (ATU) within the Cellular & Molecular Therapies (CMT) facility at NHSBT Bristol, under its MHRA IMP Manufacturers’ Authorisation to produce manufactured red cells (mRBC – intervention arm).

Routine tests on the samples accompanying the whole blood unit for HIV, HBV, HCV, HEV, Syphilis, ABO and Rh blood group will be performed. It is imperative for recipient safety, that recipients receive the correct unit of red cells that have been donated specifically for them and a full tracking system from donor to the recipient will be used.

Study Donors will attend at least two (and possibly additional) whole blood donation visits during the trial, each approximately 4 months apart.

2) Radiolabelling:
Prior to infusion, the cross-matching results will be checked. Bacteriology results will also be checked (sRBC and mRBC). On day 8-10 of red cell storage, the cells will be transferred to the Radiopharmacy Unit, Guy's Hospital where the cells will be radiolabelled with Cr51 according to the trial-specific Standard Operating Procedure. Haemolysis levels in the supernatant from the labelled cells will be checked prior to their release from the Radiopharmacy Unit for infusion into the volunteers.

3) Recipients (participants):
A medical history and assessment will be undertaken at the consent visit and reassessed on the day of infusion. Participants will attend the Addenbrooke’s Clinical Research Facility for infusion of standard red cells and mRBCs at visits at least 4 months apart. Following each infusion, on the day of infusion blood samples will be taken at 5, 7.5, 10, 12.5, 15, 30 and 60 minutes. Further single blood samples will be taken at 1, 2, 3, 7, 14, 21, 28, 35, 42, 49, 75, 100 and 120 days post infusion in order to assess post-infusion survival of the red cells and to screen for red cell alloantibody formation.

Procedures post infusion:
1) EDTA blood samples (10 ml) will be taken for assessment of red cell survival at 5, 7.5, 10, 12.5, 15, 30 and 60 minutes post transfusion of the radiolabelled red cells. An additional sample will be taken at 24 hours and then on day 2, 3, 7, 14, 21, 28, 35, 42, 49 75, 100 and 120. Samples will be transferred to the Nuclear Medicine department where they will be subsequently analysed.
2) Basic observations for safety (pulse, temperature and blood pressure) will be recorded during the whole 6 hours spent by the recipients on the CRF and at each sampling done thereafter at the recipient's place of choice.
Additionally, participants will be counselled on the need to telephone for advice if they become unwell or experience any adverse reactions. Pharmacovigilance reporting will be undertaken as part of the trial.
Intervention typeBiological/Vaccine
Pharmaceutical study type(s)
PhasePhase I
Drug / device / biological / vaccine name(s)Radiolabelled red blood cells, standard red blood cells (sRBC) and manufactured red blood cells (mRBC)
Primary outcome measureCo-primary outcome measures:
1. Safety as assessed by:
1.1. Serological detection of new red cell alloantibodies against standard and/or manufactured red blood cells at 120 days after the first infusion of red blood cells and at up to 180 days after the second infusion of red blood cells.
1.2. Description of all serious adverse reactions that occur from day of infusion of RBCs until up to 180 days after the second infusion of red blood cells.
2. Survival of Red Blood Cells is measured as the time it takes for 50% of the radiolabelled RBCs to be cleared from the circulation (T50). Blood samples are taken at 5, 7.5, 10, 12.5, 15, 30 and 60 minutes post transfusion of the radiolabelled RBCs and then at 24 hours and then on days 2, 3, 7, 14, 21, 28, 35, 42, 49 75, 100 and 120.
Secondary outcome measuresPost-transfusion recovery of Red Blood Cells at 24 hours (PTR24) is measured by calculating the proportion of red blood cells infused that remain in the circulation at 24 hours following infusion
Overall study start date01/08/2018
Overall study end date31/10/2025

Eligibility

Participant type(s)Mixed
Age groupAdult
Lower age limit18 Years
Upper age limit110 Years
SexBoth
Target number of participantsPlanned Sample Size: 15; UK Sample Size: 15
Participant inclusion criteriaParticipant Inclusion Criteria (blood donors)
Blood donors must satisfy all the following criteria to be eligible for the study:
1. Born after 1st January 1996
2. Able to donate whole blood
3. Fulfil all requirements to donate whole blood for transfusion according to UK Blood Services definition at the time of donation
4. Previous successful whole blood donation
5. Willing to consent to their blood donations being used for the trial, including scheduling donation appointments to suit the needs of the trial

Participant Inclusion Criteria (recipients)
The participants (recipients) must satisfy all the following criteria to be eligible for the study:
1. Over 18 years of age
2. In good general health
3. Female and of no child-bearing potential (sterilised, post-hysterectomy or post-menopausal) or male
4. Has a blood group profile that is compatible with one of the donors who will donate units of blood for the study
5. Willing to accept that participation in the trial will prevent them from becoming a blood donor or donating blood in the future, as is the case for individuals who have received a blood transfusion. Willing to accept that participation in the trial may affect their ability to donate organs or tissues in the future.
6. Able and willing to keep to the trial schedule
7. Able and willing to provide informed consent to participate
8. Female participants will need to have a negative pregnancy test on the day of infusion, even though they will have confirmed they have no child-bearing potential. Based on the dose of radiation received, there is no requirement for male participants to use contraception or for any recipients to avoid proximity with pregnant women
Participant exclusion criteriaCurrent exclusion criteria as of 13/02/2024:
Participant Exclusion Criteria (blood donors)
Blood donors may not donate for the study if ANY of the following apply:
1. Confirmed positive for any microbiological tests performed on blood donors on a sample tested at the time of donation (Hepatitis B (HBV), Hepatitis C (HCV), Hepatitis E (HEV), Human Immunodeficiency Virus (HIV), Human T-cell Lymphotropic Virus (HTLV), syphilis)
2. A positive direct antiglobulin test (DAT)
3. The presence of Sickle Cell Trait (HbAS), glucose-6-phosphate dehydrogenase (G6PD) deficiency, pseudohyperkalaemia
4. Have plans to travel in regions that would justify their deferral as a blood donor at the time of donation
5. Within 30 days of participating in another clinical trial, at the CI’s discretion
6. Unable to use videoconferencing for study visits, at the CI's discretion

Participant Exclusion Criteria (recipients)
Potential participants (recipients) may not enter the study if ANY of the following apply:
screening tests.
2. Previous splenectomy.
3. Participation in another clinical trial within the last 30 days or currently participating in another clinical trial.
4. Receipt of radio-isotopes within the last 12 months, unless given as part of the RESTORE trial.
5. Past or present occupational exposure to radiation that necessitates or necessitated the wearing of a monitoring badge
6. Known allergy to Cr-51
7. Known allergies warranting the use of adrenaline (EpiPen)
8. Positive for clinically significant red cell alloantibodies, as detected by routine serological methods, including 3 cell screen.
9. Positive for any other cross-match reactivity on screening.
10. Positive pregnancy test
11. Females that are breastfeeding
12. Surgery planned for the period of study participation unless the CI/screening physician deems the risk of the participant experiencing substantial blood loss during that surgery as very low and unlikely to require a blood transfusion.
13. Subject to enhanced COVID-19 restrictions at the time of recruitment, due to clinical status, at the physician’s discretion (e.g. “shielding” or “clinically vulnerable”).
14. Unable to use videoconferencing for study visits, at the CI/trial physician’s discretion.


Previous exclusion criteria:
Participant Exclusion Criteria (blood donors)
Blood donors may not donate for the study if ANY of the following apply:
1. Confirmed positive for any microbiological tests performed on blood donors on a sample tested at the time of donation (Hepatitis B (HBV), Hepatitis C (HCV), Hepatitis E (HEV), Human Immunodeficiency Virus (HIV), Human T-cell Lymphotropic Virus (HTLV), syphilis)
2. A positive direct antiglobulin test (DAT)
3. The presence of Sickle Cell Trait (HbAS), glucose-6-phosphate dehydrogenase (G6PD) deficiency, pseudohyperkalaemia
4. Have plans to travel in regions that would justify their deferral as a blood donor at the time of donation
5. Within 30 days of participating in another clinical trial, at the CI’s discretion

Participant Exclusion Criteria (recipients)
Potential participants (recipients) may not enter the study if ANY of the following apply:
1. Any clinically relevant abnormality on history, physical examination or laboratory screening tests
2. Previous splenectomy
3. Participation in another clinical trial within the last 30 days or currently participating in another clinical trial
4. Receipt of radio-isotopes within the last 12 months
5. Past or present occupational exposure to radiation that necessitates or necessitated wearing of a monitoring badge
6. Known allergy to Cr-51
7. Known allergies warranting the use of adrenaline (EpiPen)
8. Positive for red cell antibodies on screening.
9. Positive for any other cross-match reactivity on screening.
10. Positive pregnancy test
11. Females that are breastfeeding
12. Surgery planned for the period of study participation
Recruitment start date13/05/2021
Recruitment end date30/11/2024

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

NHS Blood and Transplant, Cambridge Donor Centre (lead centre)
Cambridge Clinical Research Facility
Addenbrooke’s Hospital
Hills Road
Cambridge
CB2 0QQ
United Kingdom

Sponsor information

NHS Blood and Transplant R&D Office
Hospital/treatment centre

NHS Blood and Transplant
500 North Bristol Park
Filton
Bristol
BS34 7QH
England
United Kingdom

Phone +44 (0)1179217451
Email research.office@nhsbt.nhs.uk
Website https://www.nhsbt.nhs.uk/
ROR logo "ROR" https://ror.org/0227qpa16

Funders

Funder type

Government

NHS Blood and Transplant
Government organisation / Local government
Alternative name(s)
National Health Service Blood and Transplant, UK National Health Service Blood and Transplant, NHSBT
Location
United Kingdom
NIHR Central Commissioning Facility (CCF); Grant Codes: BTRU-2015-10032

No information available

Results and Publications

Intention to publish date31/10/2026
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryAvailable on request
Publication and dissemination planPlanned publication in a high-impact peer-reviewed journal
IPD sharing planThe datasets generated during and/or analysed during the current study will be available upon request from the NHSBT Clinical Trials Unit after de-identification (text, tables, figures and appendices) 9 months after publication and ending 5 years following article publication. Data will be shared with investigators whose use of the data has been assessed and approved by an NHSBT review committee as a methodologically sound proposal.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
HRA research summary 28/06/2023 No No

Editorial Notes

01/04/2025: Contact details updated.
11/11/2024: The following changes were made to the study record:
1. The overall study end date was changed from 31/05/2025 to 31/10/2025.
2. The intention to publish date was changed from 30/05/2026 to 31/10/2026.
13/02/2024: The following changes were made to the study record:
1. The overall study end date was changed from 30/11/2024 to 31/05/2025.
2. The intention to publish date was changed from 30/03/2025 to 30/05/2026.
3. The exclusion criteria were updated.
11/09/2023: The recruitment end date was changed from 30/09/2023 to 30/11/2024.
21/04/2023: The overall end date was changed from 30/05/2024 to 30/11/2024.
07/03/2023: The participant level data sharing statement was added.
12/12/2022: A contact was updated.
07/12/2022: The following changes were made to the trial record:
1. The overall trial end date was changed from 30/03/2024 to 30/05/2024 and the plain English summary was updated accordingly.
2. Drug names were added.
3. Trial website was added.
11/11/2021: The following changes were made to the trial record:
1. The recruitment start date was changed from 01/09/2019 to 13/05/2021.
2. The recruitment end date was changed from 30/11/2021 to 30/09/2023.
3. The overall trial end date was changed from 30/05/2022 to 30/03/2024.
4. The intention to publish date was added.
5. The IPD sharing statement was added.
02/07/2019: Trial's existence confirmed by the NIHR.