Sandeep Soni

Transfusion-dependent -thalassemia (TDT) and sickle cell disease (SCD) are severe monogenic diseases with severe and potentially life-threatening manifestations. BCL11A is a transcription factor that represses -globin expression and fetal hemoglobin in erythroid cells. We performed electroporation of CD34+ hematopoietic stem and progenitor cells obtained from healthy donors, with CRISPR-Cas9 targeting the BCL11A erythroid-specific enhancer. Approximately 80% of the alleles at this locus were modified, with no evidence of off-target editing. After undergoing myeloablation, two patients -one with TDT and the other with SCD -received autologous CD34+ cells edited with CRISPR-Cas9 targeting the same BCL11A enhancer. More than a year later, both patients had high levels of allelic editing in bone marrow and blood, increases in fetal hemoglobin that were distributed pancellularly, transfusion independence, and (in the patient with SCD) elimination of vaso-occlusive episodes. (Funded by CRISPR Therapeutics and Vertex Pharmaceuticals; ClinicalTrials.gov numbers, NCT03655678 for CLIMB THAL-111 and NCT03745287 for CLIMB SCD-121.) 2] Mutations in HBB that cause TDT 4 result in reduced ( + ) or absent ( 0 ) -globin synthesis and an imbalance between the -like and -like globin (e.g., , , and ) chains of hemoglobin, which causes ineffective erythropoiesis. Sickle hemoglobin is the result of a point mutation in HBB that replaces glutamic acid with valine at amino acid position 6. Polymerization of deoxygenated sickle hemoglobin causes erythrocyte deformation, hemolysis, anemia, painful vaso-occlusive episodes, irreversible end-organ damage, and a reduced life expectancy. reatment options primarily consist of transfusion and iron chelation in patients with TDT 7 and pain management, transfusion, and hydroxyurea in those with SCD. 8 Recently approved therapies, including luspatercept 9 and crizanlizumab, 10 have reduced transfusion requirements in patients with TDT and the incidence of vaso-occlusive episodes in those with SCD, respectively, but neither treatment addresses the underlying cause of the disease nor fully ameliorates disease manifestations. Allogeneic bone marrow transplantation can cure both TDT and

Sickle cell disease results from a homozygous missense mutation in the -globin gene that causes polymerization of hemoglobin S. Gene therapy for patients with this disorder is complicated by the complex cellular abnormalities and challenges in achieving effective, persistent inhibition of polymerization of hemoglobin S. We describe our first patient treated with lentiviral vector-mediated addition of an antisickling -globin gene into autologous hematopoietic stem cells. Adverse events were consistent with busulfan conditioning. Fifteen months after treatment, the level of therapeutic antisickling -globin remained high (approximately 50% of -like-globin chains) without recurrence of sickle crises and with correction of the biologic hallmarks of the disease. (Funded by Bluebird Bio and others; HGB-205 ClinicalTrials.gov number, NCT02151526.) S ickle cell disease is among the most prevalent inherited monogenic disorders. Approximately 90,000 people in the United States have sickle cell disease, and worldwide more than 275,000 infants are born with the disease annually. 1,2 Sickle cell disease was the first disease for which the molecular basis was identified: a single amino acid substitution in "adult" A -globin (Glu6Val) stemming from a single base substitution (AT) in the first exon of the human A -globin gene (HBB) was discovered in 1956. Sickle hemoglobin (HbS) polymerizes on deoxygenation, reducing the deformability of red cells. Patients have intensely painful vaso-occlusive crises, leading to irreversible organ damage, poor quality of life, and reduced life expectancy. Hydroxyurea, a cytotoxic agent that is capable of boosting fetal hemoglobin levels in some patients, is the only disease-modifying therapy approved for sickle cell disease. llogeneic hematopoietic stem-cell transplantation currently offers the only curative option for patients with severe sickle cell disease. However, fewer than 18% of patients have access to a matched sibling donor. Therapeutic ex vivo gene transfer into autologous hematopoietic stem cells, referred to here as gene therapy, may provide a long-term and potentially curative treatment for sickle cell disease. e previously reported proof of effective, sustained gene therapy in mouse mod-

Donor availability and transplantation-related risks limit the broad use of allogeneic

In uncontrolled hemorrhage, the main cause of death on the battlefield and in accidents, half of the deaths are caused by severe blood loss. Polymeric biomaterials have great potential in the control of severe hemorrhage from trauma, which is the second leading cause of death in the civilian community following central nervous system injuries. The intent of this article is to provide a review on currently available biopolymers used as wound dressing agents and to describe their best use as it relates to the condition and type of the wound (acute, chronic, superficial, and full thickness) and the phases of the wound healing process. These biopolymers are beneficial in tissue engineering as scaffolds, hydrogels, and films. Different types of wound dressings based on biopolymers are available in the market, with various physical, chemical, and biological properties. The use of biopolymers as a hemostatic agent depends on its biocompatibility, biodegradability, nonimmunogenicity, and optimal mechanical property. This review summarizes different biopolymers, their physiological characters, and their use as wound healing agents along with biomedical applications.

Background: BCL11A is a key transcription factor that suppresses the production of fetal hemoglobin (HbF) in red blood cells (RBCs), leading to the production of adult Hb (HbA). In diseases with hemoglobin production defects such as b-thalassemia, or in sickle cell disease (SCD), HbF upregulation could ameliorate anemia and reduce transfusion requirements, such as in β-thalassemia, or reduce clinical complications, including vaso-occlusive crises (VOCs), in SCD. To induce potentially curative levels of HbF in erythrocytes, we used the ex vivo CRISPR-Cas9-based gene-editing platform to edit the erythroid enhancer region of BCL11A in hematopoietic stem and progenitor cells (HSPCs), producing CTX001. Aims: CLIMB THAL-111 (NCT03655678) and CLIMB SCD-121 (NCT03745287) are multi-center, first-in-human studies of CTX001 for transfusion-dependent b-thalassemia (TDT) and SCD, respectively. Here, we present available safety and efficacy results from all patients with at least 3 months of follow-up from both studies as of July 2020. Methods: Patients (aged 18 to 35 years) with TDT receiving packed red blood cell (pRBC) transfusions of ≥100 mL/kg/year or ≥10 units/year in the previous 2 years, and those with severe SCD, defined as ≥2 VOCs/year requiring medical care in the previous 2 years, were eligible. Peripheral CD34+ HSPCs were collected by apheresis after mobilization with G-CSF (filgrastim) and plerixafor (for TDT) or plerixafor alone (SCD). The erythroid enhancer region of BCL11A was edited in CD34+ cells using a specific CRISPR guide RNA and Cas9 nuclease. Prior to CTX001 infusion on Day +1, patients received myeloablation with 4 days of busulfan. Patients were monitored for stem cell engraftment and hematopoietic recovery, adverse events, total Hb and HbF production, hemolysis, F-cells, pRBC transfusion requirements (TDT), and VOCs (SCD) during follow-up. Results: Data are presented for patients with TDT (N=5; RBC transfusion history range: 23.5 to 61 units/year; CTX001 post-infusion follow-up through Months 15, 6, 4, 4, and 3, respectively) and with SCD (N=2; 7 VOCs/year and 7.5 VOCs/year, respectively, annualized over 2 years prior to consent; CTX001 post-infusion follow-up through Months 12 and 3, respectively). In the patients with TDT, median neutrophil engraftment occurred on Day +32 (range: +27 to +36); median platelet engraftment occurred on Day +37 (range: +34 to +52). In the patients with SCD, neutrophil engraftment occurred on Day +30 and Day +22 and platelet engraftment occurred on Day +30 and Day +33, respectively. All patients demonstrated increases in total Hb and HbF over time (Figure). Patients with TDT ceased receiving pRBC transfusions soon after CTX001 infusion, with the last pRBC transfusion occurring between 0.9 and 1.9 months after CTX001 infusion. The first patient with TDT who received CTX001 has remained transfusion-free for over 15 months. Patients with SCD have had no VOCs since CTX001 infusion. The first SCD patient who received CTX001 has remained free of VOCs for over 1 year. In all 7 patients, the safety profile after CTX001 infusion was generally consistent with busulfan myeloablation. Four serious adverse events (SAEs) related or possibly related to CTX001 were reported in 1 patient with TDT: headache, haemophagocytic lymphohistiocytosis (HLH), acute respiratory distress syndrome, and idiopathic pneumonia syndrome. All 4 of these SAEs occurred in the context of HLH and were either resolved or clinically improving at the time of this analysis. No other CTX001-related SAEs were reported in the other patients with TDT or in any patients with SCD. Conclusions: These data demonstrate that CTX001, a first-in-human, CRISPR-Cas9-modified autologous HSPC product, has resulted in increases in HbF and total Hb in the first 7 patients infused. All patients infused with CTX001 demonstrated hematopoietic engraftment with a post-infusion safety profile generally consistent with myeloablation. All 5 patients with TDT have been transfusion-free since ~2 months after CTX001 infusion and the 2 patients with severe SCD have had no VOCs during follow-up after CTX001 infusion. These early data demonstrate that CTX001 is a potential functional cure for the treatment of TDT and SCD. Data will be updated for the presentation. Data from these ongoing studies were submitted on behalf of the CLIMB THAL-111 and CLIMB SCD-121 Investigators. Figure Disclosures Frangoul: Vertex Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Bobruff:CRISPR Therapeutics: Current Employment, Current equity holder in publicly-traded company. Cappellini:BMS: Honoraria; CRISPR Therapeutics, Novartis, Vifor Pharma: Membership on an entity's Board of Directors or advisory committees; Genzyme/Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees. Fernandez:CRISPR Therapeutics: Current Employment, Current equity holder in publicly-traded company. Grupp:Juno/BMS: Other; Cellectis: Other; TCR2: Other: SAB; Servier: Research Funding; Janssen/JnJ: Consultancy; CBMG: Consultancy; Humanigen: Consultancy; GlaxoSmithKline: Consultancy; Roche: Consultancy; CRISPR Therapeutics/Vertex Pharmaceuticals: Other; Allogene: Other; Kite/Gilead: Research Funding; Novartis: Consultancy, Other: SSC, Research Funding; Adaptimmune: Other: SAB; Jazz: Other: SSC. Handgretinger:Amgen: Honoraria. Ho:CRISPR Therapeutics: Current Employment, Current equity holder in publicly-traded company. Imren:Vertex Pharmaceuticals Incorporated: Current Employment, Current equity holder in publicly-traded company. Kattamis:Agios: Consultancy; Vertex: Membership on an entity's Board of Directors or advisory committees; Ionis: Membership on an entity's Board of Directors or advisory committees; Genesis Pharma SA: Membership on an entity's Board of Directors or advisory committees; Vifor: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene/BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Apopharma/Chiesi: Honoraria, Speakers Bureau. Lekstrom-Himes:Vertex Pharmaceuticals Incorporated: Current Employment, Current equity holder in publicly-traded company. Locatelli:Medac: Speakers Bureau; Miltenyi: Speakers Bureau; Bellicum Pharmaceutical: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceeutical: Speakers Bureau. Lu:Vertex Pharmaceuticals Incorporated: Current Employment, Current equity holder in publicly-traded company. de Montalembert:Bluebird bio: Honoraria, Membership on an entity's Board of Directors or advisory committees; Vertex: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Addmedica: Honoraria, Membership on an entity's Board of Directors or advisory committees. Mulcahey:Vertex Pharmaceuticals Incorporated: Current Employment, Current equity holder in publicly-traded company. Shanbhag:Vertex Pharmaceuticals Incorporated: Current Employment, Current equity holder in publicly-traded company. Sheth:Agios: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; La Jolla: Research Funding; Acceleron: Consultancy; Bluebird Bio: Consultancy; Novartis: Consultancy, Research Funding; DisperSol Technologies: Research Funding; Terumo: Research Funding; Vertex Pharmaceuticals/CRISPR Therapeutics: Membership on an entity's Board of Directors or advisory committees. Soni:CRISPR Therapeutics: Current Employment, Current equity holder in private company. Steinberg:Vertex Pharmaceuticals/CRISPR Therapeutics: Membership on an entity's Board of Directors or advisory committees; Fulcrum Therapeutics: Membership on an entity's Board of Directors or advisory committees; DSMB: Membership on an entity's Board of Directors or advisory committees; Imara: Membership on an entity's Board of Directors or advisory committees. Weinstein:CRISPR Therapeutics: Current Employment, Current equity holder in publicly-traded company. Wu:Bayer: Research Funding; Novo Nordisk: Membership on an entity's Board of Directors or advisory committees; Octapharma: Membership on an entity's Board of Directors or advisory committees; CSL Behring: Membership on an entity's Board of Directors or advisory committees; Bioverativ: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees.