CRISPR-Cas9 Modified Stem Cells for Sickle Cell Disease
Recruiting in Palo Alto (17 mi)
+6 other locations
Age: < 18
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Phase 3
Recruiting
Sponsor: Vertex Pharmaceuticals Incorporated
Must be taking: Hydroxyurea
Disqualifiers: HLA-matched donor, Prior HSCT, Infections, others
No Placebo Group
Pivotal Trial (Near Approval)
Prior Safety Data
Approved in 2 Jurisdictions
Trial Summary
What is the purpose of this trial?This is a single-dose, open-label study in pediatric participants with severe SCD and hydroxyurea (HU) failure or intolerance. The study will evaluate the safety and efficacy of autologous CRISPR-Cas9 modified CD34+ human hematopoietic stem and progenitor cells (hHSPCs) (CTX001).
Will I have to stop taking my current medications?
The trial information does not specify whether you need to stop taking your current medications. However, since the study involves participants with hydroxyurea failure or intolerance, it might be assumed that hydroxyurea is not required during the trial.
What data supports the effectiveness of the treatment CTX001, exa-cel for sickle cell disease?
Research shows that using CRISPR-Cas9 to edit stem cells can effectively correct the genetic mutation causing sickle cell disease. Studies have demonstrated that this approach can increase healthy hemoglobin levels and reduce sickle hemoglobin, potentially leading to clinical benefits for patients.
12345Is the CRISPR-Cas9 treatment for sickle cell disease safe for humans?
Preclinical studies show that CRISPR-Cas9 gene editing for sickle cell disease appears safe, with no evidence of abnormal blood cell development, cancer risk, or other toxic effects in animal models.
12356How is the treatment CTX001 for sickle cell disease different from other treatments?
CTX001 is unique because it uses CRISPR-Cas9 technology to edit the patient's own stem cells, correcting the genetic mutation that causes sickle cell disease. This approach aims to provide a long-lasting solution by directly addressing the root cause of the disease, unlike traditional treatments that mainly manage symptoms.
12457Eligibility Criteria
This trial is for children with severe Sickle Cell Disease who have had at least two serious pain episodes a year and haven't responded well to or can't tolerate Hydroxyurea treatment. They should be suitable for their own stem cell transplant, not have had one before, and not currently have any major infections.Inclusion Criteria
I have been diagnosed with severe sickle cell disease.
I am considered a candidate for a stem cell transplant using my own cells.
I've had two or more severe pain crises a year for the last two years.
+1 more
Exclusion Criteria
I do not have any active serious infections.
I have a healthy, fully matched donor for my treatment.
I have had a stem cell transplant before.
Trial Timeline
Screening
Participants are screened for eligibility to participate in the trial
2-4 weeks
Treatment
Participants receive a single infusion of CTX001 through a central venous catheter
1 day
Follow-up
Participants are monitored for safety and effectiveness after treatment
24 weeks
Open-label extension (optional)
Participants may opt into continuation of treatment long-term
Long-term
Participant Groups
The study tests CTX001, which involves editing the patient's stem cells using CRISPR-Cas9 technology to treat severe SCD. It's an open-label trial meaning everyone knows they're getting this single-dose experimental therapy.
1Treatment groups
Experimental Treatment
Group I: CTX001Experimental Treatment1 Intervention
CTX001 (autologous CD34+ hHSPCs modified with CRISPR-Cas9 at the erythroid lineage-specific enhancer of the BCL11A gene). Participants will receive single infusion of CTX001 through central venous catheter.
CTX001 is already approved in European Union, United States for the following indications:
🇪🇺 Approved in European Union as CTX001 for:
- Transfusion-dependent β-thalassemia (TDT)
- Severe sickle cell disease (SCD)
🇺🇸 Approved in United States as CTX001 for:
- Transfusion-dependent β-thalassemia (TDT)
- Severe sickle cell disease (SCD)
Find a Clinic Near You
Research Locations NearbySelect from list below to view details:
The Children's Hospital at TriStar Centennial Medical Center/ Sarah Cannon Center for Blood CancersNashville, TN
Atrium Health Levine Children's HospitalCharlotte, NC
Children's Hospital of PhiladelphiaPhiladelphia, PA
St. Jude Children's Research HospitalMemphis, TN
Loading ...
Who Is Running the Clinical Trial?
Vertex Pharmaceuticals IncorporatedLead Sponsor
CRISPR TherapeuticsIndustry Sponsor
References
Combination of lentiviral and genome editing technologies for the treatment of sickle cell disease. [2023]Sickle cell disease (SCD) is caused by a mutation in the β-globin gene leading to polymerization of the sickle hemoglobin (HbS) and deformation of red blood cells. Autologous transplantation of hematopoietic stem/progenitor cells (HSPCs) genetically modified using lentiviral vectors (LVs) to express an anti-sickling β-globin leads to some clinical benefit in SCD patients, but it requires high-level transgene expression (i.e., high vector copy number [VCN]) to counteract HbS polymerization. Here, we developed therapeutic approaches combining LV-based gene addition and CRISPR-Cas9 strategies aimed to either knock down the sickle β-globin and increase the incorporation of an anti-sickling globin (AS3) in hemoglobin tetramers, or to induce the expression of anti-sickling fetal γ-globins. HSPCs from SCD patients were transduced with LVs expressing AS3 and a guide RNA either targeting the endogenous β-globin gene or regions involved in fetal hemoglobin silencing. Transfection of transduced cells with Cas9 protein resulted in high editing efficiency, elevated levels of anti-sickling hemoglobins, and rescue of the SCD phenotype at a significantly lower VCN compared to the conventional LV-based approach. This versatile platform can improve the efficacy of current gene addition approaches by combining different therapeutic strategies, thus reducing the vector amount required to achieve a therapeutic VCN and the associated genotoxicity risk.
Development of β-globin gene correction in human hematopoietic stem cells as a potential durable treatment for sickle cell disease. [2022]Sickle cell disease (SCD) is the most common serious monogenic disease with 300,000 births annually worldwide. SCD is an autosomal recessive disease resulting from a single point mutation in codon six of the β-globin gene (HBB). Ex vivo β-globin gene correction in autologous patient-derived hematopoietic stem and progenitor cells (HSPCs) may potentially provide a curative treatment for SCD. We previously developed a CRISPR-Cas9 gene targeting strategy that uses high-fidelity Cas9 precomplexed with chemically modified guide RNAs to induce recombinant adeno-associated virus serotype 6 (rAAV6)-mediated HBB gene correction of the SCD-causing mutation in HSPCs. Here, we demonstrate the preclinical feasibility, efficacy, and toxicology of HBB gene correction in plerixafor-mobilized CD34+ cells from healthy and SCD patient donors (gcHBB-SCD). We achieved up to 60% HBB allelic correction in clinical-scale gcHBB-SCD manufacturing. After transplant into immunodeficient NSG mice, 20% gene correction was achieved with multilineage engraftment. The long-term safety, tumorigenicity, and toxicology study demonstrated no evidence of abnormal hematopoiesis, genotoxicity, or tumorigenicity from the engrafted gcHBB-SCD drug product. Together, these preclinical data support the safety, efficacy, and reproducibility of this gene correction strategy for initiation of a phase 1/2 clinical trial in patients with SCD.
Cas9 protein delivery non-integrating lentiviral vectors for gene correction in sickle cell disease. [2021]Gene editing with the CRISPR-Cas9 system could revolutionize hematopoietic stem cell (HSC)-targeted gene therapy for hereditary diseases, including sickle cell disease (SCD). Conventional delivery of editing tools by electroporation limits HSC fitness due to its toxicity; therefore, efficient and non-toxic delivery remains crucial. Integrating lentiviral vectors are established for therapeutic gene delivery to engraftable HSCs in gene therapy trials; however, their sustained expression and size limitation preclude their use for CRISPR-Cas9 delivery. Here, we developed a Cas9 protein delivery non-integrating lentiviral system encoding guide RNA and donor DNA, allowing for transient endonuclease function and inclusion of all editing tools in a single vector (all-in-one). We demonstrated efficient one-time correction of the SCD mutation in the endogenous βs-globin gene up to 42% at the protein level (p
Novel HDAd/EBV Reprogramming Vector and Highly Efficient Ad/CRISPR-Cas Sickle Cell Disease Gene Correction. [2018]CRISPR/Cas enhanced correction of the sickle cell disease (SCD) genetic defect in patient-specific induced Pluripotent Stem Cells (iPSCs) provides a potential gene therapy for this debilitating disease. An advantage of this approach is that corrected iPSCs that are free of off-target modifications can be identified before differentiating the cells into hematopoietic progenitors for transplantation. In order for this approach to be practical, iPSC generation must be rapid and efficient. Therefore, we developed a novel helper-dependent adenovirus/Epstein-Barr virus (HDAd/EBV) hybrid reprogramming vector, rCLAE-R6, that delivers six reprogramming factors episomally. HDAd/EBV transduction of keratinocytes from SCD patients resulted in footprint-free iPSCs with high efficiency. Subsequently, the sickle mutation was corrected by delivering CRISPR/Cas9 with adenovirus followed by nucleoporation with a 70 nt single-stranded oligodeoxynucleotide (ssODN) correction template. Correction efficiencies of up to 67.9% (β(A)/[β(S)+β(A)]) were obtained. Whole-genome sequencing (WGS) of corrected iPSC lines demonstrated no CRISPR/Cas modifications in 1467 potential off-target sites and no modifications in tumor suppressor genes or other genes associated with pathologies. These results demonstrate that adenoviral delivery of reprogramming factors and CRISPR/Cas provides a rapid and efficient method of deriving gene-corrected, patient-specific iPSCs for therapeutic applications.
Selection-free genome editing of the sickle mutation in human adult hematopoietic stem/progenitor cells. [2021]Genetic diseases of blood cells are prime candidates for treatment through ex vivo gene editing of CD34+ hematopoietic stem/progenitor cells (HSPCs), and a variety of technologies have been proposed to treat these disorders. Sickle cell disease (SCD) is a recessive genetic disorder caused by a single-nucleotide polymorphism in the β-globin gene (HBB). Sickle hemoglobin damages erythrocytes, causing vasoocclusion, severe pain, progressive organ damage, and premature death. We optimize design and delivery parameters of a ribonucleoprotein (RNP) complex comprising Cas9 protein and unmodified single guide RNA, together with a single-stranded DNA oligonucleotide donor (ssODN), to enable efficient replacement of the SCD mutation in human HSPCs. Corrected HSPCs from SCD patients produced less sickle hemoglobin RNA and protein and correspondingly increased wild-type hemoglobin when differentiated into erythroblasts. When engrafted into immunocompromised mice, ex vivo treated human HSPCs maintain SCD gene edits throughout 16 weeks at a level likely to have clinical benefit. These results demonstrate that an accessible approach combining Cas9 RNP with an ssODN can mediate efficient HSPC genome editing, enables investigator-led exploration of gene editing reagents in primary hematopoietic stem cells, and suggests a path toward the development of new gene editing treatments for SCD and other hematopoietic diseases.
Preclinical evaluation for engraftment of CD34+ cells gene-edited at the sickle cell disease locus in xenograft mouse and non-human primate models. [2022]Sickle cell disease (SCD) is caused by a 20A > T mutation in the β-globin gene. Genome-editing technologies have the potential to correct the SCD mutation in hematopoietic stem cells (HSCs), producing adult hemoglobin while simultaneously eliminating sickle hemoglobin. Here, we developed high-efficiency viral vector-free non-footprint gene correction in SCD CD34+ cells with electroporation to deliver SCD mutation-targeting guide RNA, Cas9 endonuclease, and 100-mer single-strand donor DNA encoding intact β-globin sequence, achieving therapeutic-level gene correction at DNA (∼30%) and protein (∼80%) levels. Gene-edited SCD CD34+ cells contributed corrected cells 6 months post-xenograft mouse transplant without off-target δ-globin editing. We then developed a rhesus β-to-βs-globin gene conversion strategy to model HSC-targeted genome editing for SCD and demonstrate the engraftment of gene-edited CD34+ cells 10-12 months post-transplant in rhesus macaques. In summary, gene-corrected CD34+ HSCs are engraftable in xenograft mice and non-human primates. These findings are helpful in designing HSC-targeted gene correction trials.
Editing a γ-globin repressor binding site restores fetal hemoglobin synthesis and corrects the sickle cell disease phenotype. [2022]Sickle cell disease (SCD) is caused by a single amino acid change in the adult hemoglobin (Hb) β chain that causes Hb polymerization and red blood cell (RBC) sickling. The co-inheritance of mutations causing fetal γ-globin production in adult life hereditary persistence of fetal Hb (HPFH) reduces the clinical severity of SCD. HPFH mutations in the HBG γ-globin promoters disrupt binding sites for the repressors BCL11A and LRF. We used CRISPR-Cas9 to mimic HPFH mutations in the HBG promoters by generating insertions and deletions, leading to disruption of known and putative repressor binding sites. Editing of the LRF-binding site in patient-derived hematopoietic stem/progenitor cells (HSPCs) resulted in γ-globin derepression and correction of the sickling phenotype. Xenotransplantation of HSPCs treated with gRNAs targeting the LRF-binding site showed a high editing efficiency in repopulating HSPCs. This study identifies the LRF-binding site as a potent target for genome-editing treatment of SCD.