AzTrials
AzTrials

Sickle Cells DiseasePhase 1/2RBCNCT04156893

RH Genotype Matched RBC Transfusions

A Phase 1/2 study testing Red cell units that are genotype matched at the RHD and RHCE loci in people with Sickle Cells Disease, run by Children's Hospital of Philadelphia at 1 site in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial summary

To determine the feasibility and efficacy of matching donor red cells by RH genotype for a cohort of chronically transfused patients with SCD. Read more about this study

Who is it for?
Ages 6 months and older
Conditions the study is for
Sickle Cells Disease
What is being tested?
Red cell units that are genotype matched at the RHD and RHCE loci
Could I receive a placebo?
No, everyone receives an active treatment
How many people
35 participants
Where
1 siteUnited States
Study dates
30 Jan 2020to Oct 2029
Phase
Phase 1/2
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 6 months and older
  • All sexes
  • No healthy volunteers
  • Child, Adult, Older adult

Who may be able to join

  • Subjects age >6 months
  • Diagnosis of SCD, all genotypes
  • Require a period of chronic red cell transfusion therapy
  • Subject/parental/guardian permission (informed consent) and if appropriate, child assent

Who cannot join

  • Rare RH genotype that would preclude identification of sufficient RBC units
  • Antigen negative requirements due to alloimmunization that would preclude identification of sufficient RBC units
  • Alloimmunized to D antigen
  • Rh alloimmunized patients for whom providing RH genotype matched blood would expose the patient to an antigen that would not be consistent with standard of care and blood bank protocols
  • Parents/guardians or subjects who, in the opinion of the Investigator, may be non-compliant with study schedules or procedures

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Stella Chou, MD contact

215-590-0947

chous@chop.edu

United States1 site, 1 recruiting

  • Children's Hospital of Philadelphia

    Philadelphia, Pennsylvania, 19104

    Stella Chou, MD, 215-590-0947, chous@chop.edu

    Stella Chou, MD

    Recruiting

Other trials in United States

About this study

Official title: RH Genotype Matched Red Cell Transfusions for Patients With Sickle Cell Disease

To determine the feasibility and efficacy of matching donor red cells by RH genotype for a cohort of chronically transfused patients with SCD.

Read the detailed description

This is a Phase 1/2 trial in patients with Sickle Cell Disease requiring chronic red cell transfusions. RH genotyped donor units will be obtained from the New York Blood Center. Patients will be matched with donor units whose RH genotypes predict no foreign Rh protein exposure to the patient. This will provide red cell matching at a level above the current standard of care (serologic C, E, and K matching). Patients will receive RH matched red cells for the duration of their chronic transfusion therapy or up to three years, whichever is shorter. In the pilot phase, we have determined it is feasible to identify RH matched donor units for the patient's RH genotype for every scheduled transfusion. We will now continue to show feasibility as well as determine efficacy by monitoring Rh alloantibody formation.

For subjects with a history of stroke/recurrent transient ischemic attack or other indication who require tight control of Hb S, and RH genotyped blood is not available, standard of care serologic matched blood would be administered rather than delaying transfusion and risking higher Hb S level.

For all subjects, standard of care serologic matched blood would be administered rather than delaying transfusion beyond 7 days.

Being tested
Red cell units that are genotype matched at the RHD and RHCE loci
Keywords
Chronic Transfusion

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Red cell units that are genotype matched at the RHD and RHCE lociBiological

    Patients will be provided with red cell units that are C, E, and K antigen matched (standard of care for patients with SCD) and genotype matched at the RHD and RHCE loci.

Study groups in NCT04156893
Study groupRoleWhat they receive
RH genotype matched red cell transfusionsExperimentalSubjects will receive RH genotyped matched red cell units for transfusion in addition to standard serologic C, E, and K antigen matching and being hemoglobin S negative, which is our institutional standard of care for patients with Sickle Cell Disease.
Receives: Biological: Red cell units that are genotype matched at the RHD and RHCE loci

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Determine the treatment efficacy by monitoring the rate of Rh alloimmunization

    A primary objective is to determine whether providing RH genotype matched red cell units can reduce or prevent Rh alloimmunization.

    Measured: 3.5 years

  2. Determine the feasibility of identifying sufficient RH genotype matched units

    A primary objective is to determine the feasibility of identifying sufficient RH genotype matched red cells for chronically transfused patients with SCD with varied RH genotypes. Approximately 20 RHD (Rhesus D) and 20 RHCE (Rhesus CE) variants have been observed in patients with SCD and will determine whether sufficient RH genotyped units can be matched to the patient's own RH genotype.

    Measured: 3.5 years

Secondary outcomes (1)

  1. Determine the rate of non-Rh alloimmunization

    A secondary objective is to determine the rate of antibody formation outside the Rh blood group system, such as anti-Kidd or -S/s.

    Measured: 3.5 years

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted8 Nov 2019
  2. Study start30 Jan 2020
  3. Primary completionApr 2029 (estimated)
  4. Study completionOct 2029 (estimated)

Resources

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 1/2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Model description
Subjects will receive RH genotype matched red cell units for transfusion. For subjects with a history of stroke/recurrent transient ischemic attack or other indication who require tight control of Hb S, and RH genotyped blood is not available, standard of care serologic matched blood would be administered rather than delaying transfusion and risking higher Hb S level. For all subjects, standard of care serologic matched blood would be administered rather than delaying transfusion beyond 7 days
Masking
None (open label)
Enrolment
35 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04156893
Sponsor's protocol ID
19-016565
Other IDs
R01HL147879, R01HL169401
Acronym
RBC
Status last verified
Apr 2026
First submitted
6 Nov 2019
Last updated
27 Apr 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: Protected Health Information (PHI) will be shared with the New York Blood Center (NYBC) to order blood for the subjects. This will be done using a secure online blood ordering system. The NYBC uses an FDA-approved HIPAA secure system called Blood Enterprise Computer System (BECS) to store patient data and results, including PHI. 3rd party computers at New York Blood Center will also store study data using study identification (ID) numbers. The purpose of having study data coded at NYBC is for specialized testing for red antigens or antibodies for which we will provide some clinical data to assist in the laboratory evaluation. To assure that the transmission of data and samples maintains confidentiality we will used study ID numbers for these samples. The master list will be maintained at the Children's Hospital of Philadelphia (CHOP). The study databases are password protected and on password protected computers at CHOP and at NYBC, that are backed up on the research servers.

Publications

  • Chou ST, Jackson T, Vege S, Smith-Whitley K, Friedman DF, Westhoff CM. High prevalence of red blood cell alloimmunization in sickle cell disease despite transfusion from Rh-matched minority donors. Blood. 2013 Aug 8;122(6):1062-71. doi: 10.1182/blood-2013-03-490623. Epub 2013 May 30.

    PubMed 23723452

  • Vichinsky EP, Earles A, Johnson RA, Hoag MS, Williams A, Lubin B. Alloimmunization in sickle cell anemia and transfusion of racially unmatched blood. N Engl J Med. 1990 Jun 7;322(23):1617-21. doi: 10.1056/NEJM199006073222301.

    PubMed 2342522

  • Yawn BP, Buchanan GR, Afenyi-Annan AN, Ballas SK, Hassell KL, James AH, Jordan L, Lanzkron SM, Lottenberg R, Savage WJ, Tanabe PJ, Ware RE, Murad MH, Goldsmith JC, Ortiz E, Fulwood R, Horton A, John-Sowah J. Management of sickle cell disease: summary of the 2014 evidence-based report by expert panel members. JAMA. 2014 Sep 10;312(10):1033-48. doi: 10.1001/jama.2014.10517.

    PubMed 25203083

  • Chou ST, Evans P, Vege S, Coleman SL, Friedman DF, Keller M, Westhoff CM. RH genotype matching for transfusion support in sickle cell disease. Blood. 2018 Sep 13;132(11):1198-1207. doi: 10.1182/blood-2018-05-851360. Epub 2018 Jul 19.

    PubMed 30026182

  • Coleman S, Westhoff CM, Friedman DF, Chou ST. Alloimmunization in patients with sickle cell disease and underrecognition of accompanying delayed hemolytic transfusion reactions. Transfusion. 2019 Jul;59(7):2282-2291. doi: 10.1111/trf.15328. Epub 2019 Apr 25.

    PubMed 31021439

  • Mewha J, Vege S, Friedman DF, Makrm S, Ochoa G, Westhoff CM, Chou ST. Red cell antigen exposures in patients with sickle cell disease receiving transfusion from Black and Hispanic donors. Blood Red Cells Iron. 2026 Jun;2(2):100059. doi: 10.1016/j.brci.2026.100059. Epub 2026 Apr 8.

    PubMed 42376265

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing Red cell units that are genotype matched at the RHD and RHCE loci in people with Sickle Cells Disease, run by Children's Hospital of Philadelphia at 1 site in United States.

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 4 inclusion and 5 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 27 Apr 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 United States. 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 combined phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

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 Stella Chou, MD (215-590-0947, chous@chop.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Determine the treatment efficacy by monitoring the rate of Rh alloimmunization (time frame: 3.5 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?

On the ClinicalTrials.gov record for NCT04156893, which also lists 6 linked publications.

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 27 Apr 2026.

AzTrials uses cookies for analytics and advertising. You can accept or reject them; the site works either way. Privacy Policy.

Free account

Keep searching with a free account

You’ve used your 3 free searches for this session. Log in or create a free AzTrials account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in