Sickle Cell DiseasePhase 1/2RestoreNCT04819841
Gene Correction in Autologous CD34+ Hematopoietic Stem Cells (HbS to HbA) to Treat Severe Sickle Cell Disease
A Phase 1/2 study testing nula-cel Drug Product in people with Sickle Cell Disease, run by Kamau Therapeutics at 6 sites in United States.
Trial summary
This study is a first-in-human, single-arm, open-label Phase I/II study of nula-cel in approximately 15 participants, diagnosed with severe Sickle Cell Disease. The primary objective is to evaluate safety of the treatment in this patient population, as well as preliminary efficacy and pharmacodynamic data. Read more about this study
- Who is it for?
- Ages 12 to 50 years
- Conditions the study is for
- Sickle Cell Disease
- What is being tested?
- nula-cel Drug Product
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 6 sitesUnited States
- Study dates
- 15 Nov 2021to 31 Dec 2028
- 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 12 to 50 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- ≥12 to ≤ 40 years
- Severe disease, as defined by having experienced at least one of the following SCD-related events despite appropriate supportive care measures:
- recurrent severe VOC (≥ 4 episodes in the preceding 2 years)
- ACS (≥ 2 episodes in the prior 2 years with at least one episode in the past year)
- Lansky/Karnofsky performance status of ≥ 80
Who cannot join
- Available 10/10 HLA-matched sibling donor
- Prior HSCT or gene therapy
- Prior or current malignancy or myeloproliferative or a significant coagulation or immunodeficiency disorder
- Clinically significant and active bacterial, viral, fungal or parasitic infection
- Pregnancy or breastfeeding in a postpartum female
- Presence of a chromosomal abnormality/mutation that may put the participant at an increased risk for MDS or AML per investigator's judgment
Trial locations and contacts
6 sites in 1 country. Contact the study team or a site near you to ask about taking part.
6 sites in 1 country
United States6 sites, 6 recruiting
- Recruiting
Nationwide Children's Hospital
Columbus, Ohio, 43205
Dalena Sanderson, Dalena.Sanderson@nationwidechildrens.org
Lauren Rayman, lauren.rayman2@nationwidechildrens.org
- Recruiting
Children's Hospital Los Angeles
Los Angeles, California, 90027
Bridget Bailey, 323-361-7382, brbailey@chla.usc.edu
Ashley Gray, MD
- Recruiting
Columbia University Irving Medical Center
New York, New York, 10032
Camila Barros, 212-342-3884, cb4149@cumc.columbia.edu
Elizabeth Shelton, eas2304@cumc.columbia.edu
- Recruiting
Memorial Sloan Kettering
New York, New York, 10065
Maria Paes Pena, paespem@mskcc.org
Jaap Jan Boelens, MD, PhD
- Recruiting
Lucile Packard Children's Hospital
Palo Alto, California, 94304
Stanford Intake Team, scgt_clinical_trials_office@lists.stanford.edu
Kat Joseph, BSN, RN, 650-725-9032, kjoseph3@stanford.edu
- Recruiting
Washington University
St Louis, Missouri, 63110
Maggie Nash, 314-273-5936, nashm@wustl.edu
John F Dipersio, MD, PhD
About this study
Official title: A Phase I/II Study of Nula-cel in Autologous CD34+ Hematopoietic Stem Cells to Convert HbS to HbA for Treating Severe Sickle Cell Disease
This study is a first-in-human, single-arm, open-label Phase I/II study of nula-cel in approximately 15 participants, diagnosed with severe Sickle Cell Disease. The primary objective is to evaluate safety of the treatment in this patient population, as well as preliminary efficacy and pharmacodynamic data.
Read the detailed description
Participants diagnosed with severe SCD will receive nula-cel via IV infusion following myeloablative conditioning in an autologous HSCT setting.
- Conditions
- Sickle Cell Disease
- Being tested
- nula-cel Drug Product
- Keywords
- sickle cell disease, sickle cell anemia, gene correction, gene therapy, CRISPR
- Medical subject headings
- Anemia, Sickle Cell
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
nula-cel Drug ProductGenetic
nula-cel is administered via IV infusion following a myeloablative conditioning regimen
| Study group | Role | What they receive |
|---|---|---|
| nula-cel Drug Product | Experimental | nula-cel Drug Product is a human autologous CRISPR-Cas9 edited and sickle mutation-corrected HSPC product. Receives: Genetic: nula-cel Drug Product |
What is being measured
The primary outcome is the main question the study is designed to answer.
Proportion of patients who reach neutrophil engraftment
Measured: 42 days post-infusion
Incidence rate of treatment-related mortality
Measured: 100 days post-infusion
Incidence rate of treatment-related mortality
Measured: 12 months post-infusion
Overall survival
Measured: 24 months post-infusion
Frequency and severity of AEs/SAEs
Measured: 24 months post-infusion
Secondary outcomes (11)
Time to neutrophil engraftment
Measured: through study completion, up to 24 months post-infusion
Time to platelet engraftment
Measured: through study completion, up to 24 months post-infusion
Evaluation of gene correction levels in peripheral myeloid cells
Measured: through study completion, up to 24 months post-infusion
Evaluation of adult Hgb as a percentage of total Hgb
Measured: through study completion, up to 24 months post-infusion
Evaluation of HbS as a percentage of total Hgb
Measured: through study completion, up to 24 months post-infusion
Total Hgb without disease-indicated transfusion support
Measured: through study completion, up to 24 months post-infusion
Change in annualized packed red blood cell (pRBC) transfusion requirements (volume and frequency) for SCD indications
Measured: through study completion, up to 24 months post-infusion
Proportion of participants with complete resolution of severe vaso-occlusive crises (sVOCs)
Measured: over time, from 6 months to 18 months post-infusion
Incidence rate of any sVOCs
Measured: over time, from 6 months to study completion, up to 24 months post-infusion
Proportion of participants achieving HbS <50% for at least 3 months
Measured: through study completion, up to 24 months post-infusion
Evaluation of globin chain expression compared to baseline
Measured: through study completion, up to 24 months post-infusion
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Mar 2021
- Study start15 Nov 2021
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sickle Cell DiseaseStudies of the same condition, open and under way.
- 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 1/2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 15 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Kamau Therapeutics
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Matthew Porteus, MD, PhD, Study director, Kamau Therapeutics
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04819841
- Sponsor's protocol ID
- KMAU-001-001
- Acronym
- Restore
- Status last verified
- Jun 2026
- First submitted
- 24 Mar 2021
- Last updated
- 2 Jul 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 2 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase I/II Study of Nula-cel in Autologous CD34+ Hematopoietic Stem Cells to Convert HbS to HbA for Treating Severe Sickle Cell Disease
- ClinicalTrials.gov ID
- NCT04819841
- Acronym / sponsor ID
- Restore / KMAU-001-001
- Conditions
- Sickle Cell Disease
- Keywords
- sickle cell disease, sickle cell anemia, gene correction, gene therapy, CRISPR
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 15 participants (estimated)
- Lead sponsor
- Kamau TherapeuticsIndustry (pharma, biotech, devices)
- Study start
- 15 Nov 2021 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2028 (estimated)
- First posted
- 29 Mar 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.
This study is a first-in-human, single-arm, open-label Phase I/II study of nula-cel in approximately 15 participants, diagnosed with severe Sickle Cell Disease. The primary objective is to evaluate safety of the treatment in this patient population, as well as preliminary efficacy and pharmacodynamic data.
Detailed description
Participants diagnosed with severe SCD will receive nula-cel via IV infusion following myeloablative conditioning in an autologous HSCT setting.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| nula-cel Drug Product | Experimental | Genetic: nula-cel Drug Productnula-cel Drug Product is a human autologous CRISPR-Cas9 edited and sickle mutation-corrected HSPC product. |
Who may qualify
- Ages
- 12 to 50 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (5 listed)
- ≥12 to ≤ 40 years
- Severe disease, as defined by having experienced at least one of the following SCD-related events despite appropriate supportive care measures:
- recurrent severe VOC (≥ 4 episodes in the preceding 2 years)
- ACS (≥ 2 episodes in the prior 2 years with at least one episode in the past year)
- Lansky/Karnofsky performance status of ≥ 80
Key exclusion criteria (6 listed)
- Available 10/10 HLA-matched sibling donor
- Prior HSCT or gene therapy
- Prior or current malignancy or myeloproliferative or a significant coagulation or immunodeficiency disorder
- Clinically significant and active bacterial, viral, fungal or parasitic infection
- Pregnancy or breastfeeding in a postpartum female
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 |
|---|---|---|
| nula-cel Drug Productnula-cel is administered via IV infusion following a myeloablative conditioning regimen | Genetic | nula-cel Drug Product |
Primary outcome
Proportion of patients who reach neutrophil engraftment
Time frame: 42 days post-infusion
Incidence rate of treatment-related mortality
Time frame: 100 days post-infusion
Incidence rate of treatment-related mortality
Time frame: 12 months post-infusion
Overall survival
Time frame: 24 months post-infusion
Frequency and severity of AEs/SAEs
Time frame: 24 months post-infusion
11 secondary outcomes
Time to neutrophil engraftment
Time frame: through study completion, up to 24 months post-infusion
Time to platelet engraftment
Time frame: through study completion, up to 24 months post-infusion
Evaluation of gene correction levels in peripheral myeloid cells
Time frame: through study completion, up to 24 months post-infusion
Evaluation of adult Hgb as a percentage of total Hgb
Time frame: through study completion, up to 24 months post-infusion
Evaluation of HbS as a percentage of total Hgb
Time frame: through study completion, up to 24 months post-infusion
Total Hgb without disease-indicated transfusion support
Time frame: through study completion, up to 24 months post-infusion
Change in annualized packed red blood cell (pRBC) transfusion requirements (volume and frequency) for SCD indications
Time frame: through study completion, up to 24 months post-infusion
Proportion of participants with complete resolution of severe vaso-occlusive crises (sVOCs)
Time frame: over time, from 6 months to 18 months post-infusion
Incidence rate of any sVOCs
Time frame: over time, from 6 months to study completion, up to 24 months post-infusion
Proportion of participants achieving HbS <50% for at least 3 months
Time frame: through study completion, up to 24 months post-infusion
Evaluation of globin chain expression compared to baseline
Time frame: through study completion, up to 24 months post-infusion
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 Jul 2026.
- Individual participant dataSharing planned: Undecided
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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.
Matthew Porteus, MD, PhD study director
Kamau Therapeutics
6 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing nula-cel Drug Product in people with Sickle Cell Disease, run by Kamau Therapeutics at 6 sites 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 5 inclusion and 6 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 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 6 sites 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 Restore Clinical Study Support (650-442-2283, RestoreStudySupport@kamautx.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Proportion of patients who reach neutrophil engraftment (time frame: 42 days post-infusion). The study lists 5 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 2 Jul 2026.