Trials For Sickle Cell Disease Research Articles

Incidence and Risk Factors for New and Recurrent Infarcts in Adults With Sickle Cell Disease.

Most adults with sickle cell disease will experience a silent cerebral infarction (SCI) or overt stroke. Identifying patient subgroups with increased stroke incidence is important for future clinical trials focused on stroke prevention. Our 3-center prospective cohort study tested the primary hypothesis that adults with sickle cell disease and SCIs have a greater incidence of new stroke or SCI compared with those without SCI. A secondary aim focused on identifying additional risk factors for progressive infarcts, particularly traditional risk factors for stroke in adults. This observational study included adults with sickle cell disease and no history of stroke. Magnetic resonance imaging scans of the brain completed at baseline and >1 year later were reviewed by 3 radiologists for baseline SCIs and new or progressive infarcts on follow-up magnetic resonance imaging. Stroke risk factors were abstracted from the medical chart. Time-to-event analysis was utilized for progressive infarcts. Median age was 24.1 years; 45.3% of 95 participants had SCIs on baseline magnetic resonance imaging. Progressive infarcts were present in 17 participants (17.9%), and the median follow-up was 2.1 years. Incidence of new infarcts was 11.95 per 100 patient-years (6.17-20.88) versus 3.74 per 100 patient-years (1.21-8.73) in those with versus without prior SCI. Multivariable Cox regression showed that baseline SCI predicts progressive infarcts (hazard ratio, 3.46 [95% CI, 1.05-11.39]; P=0.041); baseline hypertension was also associated with progressive infarcts (hazard ratio, 3.23 [95% CI, 1.16-9.51]; P=0.025). Selecting individuals with SCIs and hypertension for stroke prevention trials in sickle cell disease may enrich the study population with those at highest risk for infarct recurrence.

Motivators and Barriers for People with Sickle Cell Disease Participating in Clinical Trials: Global Findings from the LISTEN Survey

Background: The success of clinical trials of new therapies for sickle cell disease (SCD) will depend on the recruitment and retention of a large and diverse group of people with SCD (PwS). Qualitative studies have reported barriers to participation in clinical trials, including the potential impact on health, unmanageable study demands, limited knowledge of trials, and lack of trust in healthcare(Patterson CA et al. J Pediatr Hematol Oncol 2015; Lee LH et al. Blood Adv 2021). The Learning and Insights into Sickle Cell Trial Experiences (LISTEN) Survey was developed to provide a robust and comprehensive understanding of the global barriers and motivators to participation in clinical trials for PwS. Aim: To present interim findings from the LISTEN Survey regarding participation and experiences of PwS in clinical trials, barriers and motivators to participation, and differences in responses from PwS compared with perspectives of healthcare professionals (HCPs) treating PwS. Methods: Between October 6, 2022 and June 22, 2023, a broad range of adults (≥18 years) with SCD and HCPs involved in the treatment and/or clinical research of SCD in 17 countries were asked to complete corresponding quantitative surveys. PwS were asked whether they had participated in a clinical trial and, if so, whether their experience had met their expectations. PwS were asked to rate on a 7-point scale (from not at all to extremely important) and rank (from most to least important) the importance of specified factors (grouped into five categories) when deciding whether to participate in a clinical trial for SCD. HCPs provided their perspectives on the importance of these factors to PwS. The results presented here include the total proportion of respondents who rated factors as extremely or very important and the proportion who ranked factors first or second. Results: Overall, 1028 PwS (57% female) with a median age (interquartile range) of 30 years (24-37) from 16 of the 17 countries and 361 HCPs (67% hematologists and/or SCD specialists) from 17 countries completed the survey. In total, 35% of PwS had been invited to participate in a clinical trial for SCD. In PwS who had taken part in a clinical trial (24%; n=249/1028), compared with their expectations, 36% reported a better experience, 36% the same as expected experience, 9% a worse experience, and 20% did not know what to expect. Extremely or very important factors that motivated PwS to participate in a clinical trial included the potential to better manage their symptoms (52%), the opportunity to try a new treatment that might work better (51%), and to increase their knowledge of SCD (51%; Figure 1). An important barrier to participation was the potential to experience different side effects (51%). In the trial information category, PwS ranked (first or second of five) safety measures (57%) and how the treatment works (49%) as the most important factors; these were considered to be significantly more important than who is leading (27%) or funding (24%) the trial; p<0.001 for all combinations. In the further considerations category, the majority of PwS ranked (first or second of five) speaking to other PwS involved in the trial (51%) and experts running the trial (50%) as the most important factors. HCPs overstated the potential practical barriers for PwS compared with responses from PwS, including missing school/work (50% vs 42%; p=0.009), the effort required to start the trial treatment (45% vs 32%; p<0.001), and travel requirements (52% vs 36%; p<0.001). HCPs understated the importance of wider clinical trial outcomes as motivators for PwS compared with responses from PwS, including supporting new treatment developments that may benefit them (41% vs 51%; p=0.001) or other PwS (38% vs 49%; p<0.001; Figure 2). Conclusions: Improving access and recruitment into clinical trials in SCD will require clear communication of the potential benefits to individuals and the wider SCD community, as well as potential safety and side effects. Findings from the LISTEN Survey highlight that those directly involved in the trial should deliver these messages, including other PwS who are involved in the trial. Given the disconnect between PwS and HCPs, shared decision-making may also improve understanding and increase participation in clinical trials. Further analyses of the survey results will be important to identify the differences in responses between regions, age groups, and other subpopulations.

Looking ahead: ethical and social challenges of somatic gene therapy for sickle cell disease in Africa.

Somatic gene therapy will be one of the most exciting practices of genetic medicine in Africa and is primed to offer a "new life" for persons living with sickle cell disease (SCD). Recently, successful gene therapy trials for SCD in the USA have sparked a ray of hope within the SCD community in Africa. However, the high cost, estimated to exceed 1.5 million USD, continues to be a major concern for many stakeholders. While affordability is a key global health equity consideration, it is equally important to reflect on other ethical, legal and social issues (ELSIs) that may impact the responsible implementation of gene therapy for SCD in Africa. These include informed consent comprehension, risk of therapeutic misestimation and optimistic bias; priorities for SCD therapy trials; dearth of ethical and regulatory oversight for gene therapy in many African countries; identifying a favourable risk-benefit ratio; criteria for the selection of trial participants; decisional conflict in consent; standards of care; bounded justice; and genetic tourism. Given these ELSIs, we suggest that researchers, pharma, funders, global health agencies, ethics committees, science councils and SCD patient support/advocacy groups shouldwork together to co-develop: (1) patient-centric governance for gene therapy in Africa, (2) public engagement and education materials, and (3) decision making toolkits for trial participants. It is also critical to establish harmonised ethicaland regulatory frameworks for gene therapy in Africa, and for global health agencies to accelerate access to basic care for SCD in Africa, while simultaneously strengthening capacity for gene therapy.

The challenge of clinical end points in sickle cell disease

AbstractAs most patients with sickle cell disease (SCD) do not have access to curative therapies, the availability of drug therapies that can modify disease severity remains highly desirable. Despite an increased understanding of the pathophysiology of SCD, only 4 drugs are approved by the US Food and Drugs Administration. Most drug trials in SCD have involved the use of acute pain episodes as the primary clinical end point. These studies have typically been to prevent or shorten the duration of such episodes. To date, no drug has received regulatory approval for shortening the duration of acute vaso-occlusive complications, likely highlighting the complex pathophysiology of acute pain episodes. Trials to prevent acute pain episodes have largely evaluated those episodes requiring health care use as a surrogate end point. However, with differences in culture and health care practices among countries, health care use may not reliably predict clinically important effects on acute pain episodes. This article discusses issues related to the use of health care use as the primary end point for prevention trials of acute pain episodes and highlights the importance of evaluating patient-reported outcomes as well as other SCD-related complications as outcome measures.

Health Equity in Sickle Cell Research and Access to Therapy

Health Equity in Sickle Cell Research and Access to Therapy

Opening a Crack in the Door: An Interview with Haydar Frangoul

Opening a Crack in the Door: An Interview with Haydar Frangoul

Human genetic diversity alters off-target outcomes of therapeutic gene editing.

CRISPR gene editing holds great promise to modify DNA sequences in somatic cells to treat disease. However, standard computational and biochemical methods to predict off-target potential focus on reference genomes. We developed an efficient tool called CRISPRme that considers single-nucleotide polymorphism (SNP) and indel genetic variants to nominate and prioritize off-target sites. We tested the software with a BCL11A enhancer targeting guide RNA (gRNA) showing promise in clinical trials for sickle cell disease and β-thalassemia and found that the top candidate off-target is produced by an allele common in African-ancestry populations (MAF 4.5%) that introduces a protospacer adjacent motif (PAM) sequence. We validated that SpCas9 generates strictly allele-specific indels and pericentric inversions in CD34+ hematopoietic stem and progenitor cells (HSPCs), although high-fidelity Cas9 mitigates this off-target. This report illustrates how genetic variants should be considered as modifiers of gene editing outcomes. We expect that variant-aware off-target assessment will become integral to therapeutic genome editing evaluation and provide a powerful approach for comprehensive off-target nomination.

Clinical trial considerations in sickle cell disease: patient-reported outcomes, data elements, and the stakeholder engagement framework.

Patients with sickle cell disease (SCD) have significant impairment in their quality of life across the life span as a consequence of serious disease burden with several SCD-related complications. A number of disease-modifying therapies are currently available, yet long-term clinical benefits in real-world settings remain unclear. Over the past few years, a number of important initiatives have been launched to optimize clinical trials in SCD in different ways, including: (1) established panels through a partnership between the American Society of Hematology (ASH) and the US Food and Drug Administration; (2) the ASH Research Collaborative SCD Clinical Trials Network; (3) the PhenX Toolkit (consensus measures for Phenotypes and eXposures) in SCD; and (4) the Cure Sickle Cell Initiative, led by the National Heart, Lung, and Blood Institute. Electronic patient-reported outcomes assessment is highly recommended, and patient-reported outcomes (PROs) should be evaluated in all SCD trials and reported using Standard Protocol Items Recommendations for Interventional Trials guidelines. Patient-centered outcomes research (PCOR) approaches and meaningful stakeholder engagement throughout the process have the potential to optimize the execution and success of clinical trials in SCD with considerable financial value. This article reviews several clinical trial considerations in SCD related to study design and outcomes assessment as informed by recent initiatives as well as patient-centered research approaches and stakeholder engagement. A proposed hematology stakeholder-engagement framework for clinical trials is also discussed.

Bridging the implementation gap in medication adherence. If you build it, will they come?

Bridging the implementation gap in medication adherence. If you build it, will they come?

Human Genetic Diversity Alters Therapeutic Gene Editing Off-Target Outcomes

CRISPR gene editing holds great promise to modify somatic genomes to ameliorate disease. In silico prediction of homologous sites coupled with biochemical evaluation of possible genomic off-targets may predict genotoxicity risk of individual gene editing reagents. However, standard computational and biochemical methods focus on reference genomes and do not consider the impact of genetic diversity on off-target potential. Here we developed a web application called CRISPRme that explicitly and efficiently integrates human genetic variant datasets with orthogonal genomic annotations to predict and prioritize off-target sites at scale. The method considers both single-nucleotide variants (SNVs) and indels, accounts for bona fide haplotypes, accepts spacer:protospacer mismatches and bulges, and is suitable for personal genome analyses. We tested the tool with a guide RNA (gRNA) targeting the BCL11A erythroid enhancer that has shown therapeutic promise in clinical trials for sickle cell disease (SCD) and β-thalassemia (Frangoul et al. NEJM 2021). We find that the top predicted off-target site is produced by a non-reference allele common in African-ancestry populations (rs114518452, minor allele frequency (MAF) = 4.5%) that introduces a protospacer adjacent motif (PAM) for SpCas9. We validate that SpCas9 generates indels (~9.6% frequency) and chr2 pericentric inversions in a strictly allele-specific manner in edited CD34+ hematopoietic stem/progenitor cells (HSPCs), although a high-fidelity Cas9 variant mitigates this off-target. This report illustrates how population and private genetic variants should be considered as modifiers of genome editing outcomes. We expect that variant-aware off-target assessment will be required for therapeutic genome editing efforts going forward, including both ongoing and future clinical trials, and we provide a powerful approach for comprehensive off-target prediction. CRISPRme is available at crisprme.di.univr.it. DisclosuresNo relevant conflicts of interest to declare.

Patient and Caregiver Attitudes Towards Gene Therapy for Sickle Cell Disease: A Need for Partnership and Education

Background:Fewer than 20% of patients with sickle cell disease (SCD) have access to curative matched sibling donor bone marrow transplantation (MSD-BMT). Development of novel therapies to ameliorate the serious morbidity and early mortality caused by SCD is a National Institute of Health research priority. Gene therapy for SCD has emerged as a promising approach in early-stage clinical trials approach with the potential to reach greater numbers of patients than MSD-BMT. Knowledge and attitudes of individuals with SCD towards this investigational new therapy and their willingness to participate in early-stage clinical trials have not been systematically described.Methods:Patients with SCD at least 13 years of age (n=66) and caregivers of children with SCD (n=38) were surveyed about knowledge, attitudes, and beliefs regarding gene therapy for SCD. Most questions utilized a 5-item Likert response scale while The Newest Vital Sign was used to assess health literacy. To explore attitudes around gene therapy in further detail, we identified a regionally diverse focus group comprised of 12 patients/caregivers with SCD from across the United States. We audio-recorded, transcribed verbatim, and analyzed five focus group discussions using thematic content analysis to identify salient themes related to attitudes towards gene therapy for SCD. Our goal was to identify the educational needs and preferences of this patient / caregiver stakeholder group.Results:Survey: Of the 104 survey respondents 96% identified as Black and 4% as Hispanic. Respondents were between 13-64 years (mean 29.6, Std Dev 11.9 years). HbSS and HbSC were the most common genotypes (61.5% and 24%, respectively). Only 4.8% of participants (N=5) felt “extremely knowledgeable” about gene therapy for SCD while most (63.4%) reported no/slight knowledge. We found no association between health literacy levels and gene therapy knowledge (p=0.361). Nearly 30% of participants reported that the risk of cancer as a potential side effect would “probably not prevent their enrollment” on a gene therapy trial while 48% said it “definitely/probably would preclude their participation”. Most respondents had a neutral attitude regarding the safety of gene therapy for SCD and how good of a treatment it was (56.7% and 58.6%, respectively). Only a few respondents endorsed the idea that gene therapy was “unsafe” or “not a good treatment for SCD” (5.8% and 4.8% respectively). There was an association between increasing knowledge about gene therapy and agreement that it is safe (p=0.012) and a good treatment for SCD (p=0.031).Focus Groups: Among the focus group participants, there was consensus that communication about gene therapy is suboptimal. Participants noted that clinicians frequently use medical jargon, do not tailor their approach to the individual patient/caregiver, and fail to adequately disclose important details. Focus group members desired more information about side effects and risks associated with conditioning chemotherapy, immunosuppression, risk of infertility, and hair loss. Participants, particularly parents of children with SCD, were worried about future unknown risks and described the enormity of the decision to enroll in an early-phase trial. Focus group members verbalized the need for inclusion of patients with SCD as partners during the informed consent/assent process and ideally, at the outset of the clinical trial design.Conclusion:Very few patients with SCD described feeling knowledgeable about gene therapy for SCD; a majority have neutral feelings about the safety and utility (“good treatment for SCD”) of this new approach. Patient/caregiver-centered education about gene therapy in a manner that meets stakeholder informational needs is urgently needed. Given the temporary hold on lentiviral gene therapy trials for SCD (after some participants developed a myeloid neoplasm on an industry sponsored trial in February 2021) and the risk of cancer as a probable or definite barrier to enrollment in a gene therapy trial for many patients, transparency of information about these risks is essential. For the successful execution of novel trials in SCD, a community-based participatory research approach is vital. DisclosuresSharma: Medexus Inc: Consultancy; Spotlight Therapeutics: Consultancy; Novartis: Other: Salary support paid to institution; Vertex Pharmaceuticals/CRISPR Therapeutics: Other: Salary support paid to institution; Vindico Medical Education: Honoraria; CRISPR Therapeutics: Other, Research Funding. Johnson: CRISPR Therapeutics: Research Funding.

Pharmacodynamic Effects of AG-946, a Highly Potent Next-Generation Activator of Pyruvate Kinase, in Ex Vivo Treatment of Red Blood Cells from Sickle Cell Disease Patients

Background: Sickle cell disease (SCD) is a monogenetic red blood disorder that is characterized by hemolytic anemia and vaso-occlusive crises. Among the many factors that contribute to disease pathophysiology is stiffening and sickling of red blood cells (RBC), which is the direct result of the formation of abnormal hemoglobin S. Sickling is one of the core factors that cause vaso-occlusion and sickling is modulated by glycolytic intermediates such as 2,3-diphosphoglycerate (2,3-DPG) and ATP. Previously we showed that red blood cell pyruvate kinase (PKR), the key regulatory enzyme of glycolysis, is impaired in SCD and that ex vivo treatment with mitapivat, an allosteric activator of PKR, increased enzymatic activity and thermostability, reduced 2,3-DPG levels, decreased p50, and subsequently reduced sickling (Rab et al, Blood 2021). Currently, mitapivat is in phase 1 and phase 2 trials for SCD (#NCT04000165 and EudraCT#2019-003438).Aims: Recently, AG-946, a next-generation activator of PKR has been developed. Here we investigate the pharmacodynamic effects of AG-946 in ex vivo treatment of RBC from SCD patients in comparison with mitapivat.Methods: Buffy coat depleted whole blood obtained from five patients with SCD was incubated for 20-24 hrs in absence or presence of mitapivat (100 mM) or AG-946 (1 mM, 5 mM, 50 mM). After ex vivo treatment, enzymatic activities of PKR and PK-thermostability was measured. Glycolytic intermediates ATP and 2,3-DPG were measured using LC-MS/MS. Hemoglobin oxygen affinity (p50) was measured with the Hemox Analyzer. RBC sickling was analyzed with the oxygenscan, a newly developed method that characterizes individual sickling behavior by oxygen gradient ektacytometry. Individual tendency to sickle is reflected by Point-of-Sickling (PoS) that indicates the specific pO 2 at which RBCs start to sickle during deoxygenation under shear stress.Results: PKR activity was increased compared to vehicle (DMSO) to a similar extent in presence of both mitapivat and AG-946 (Figure 1A). In addition, PKR thermostability was significantly increased compared to vehicle (mean 22%, SD 6%) in samples treated with mitapivat 100 mM (mean 78%, SD 11%), as well as AG-946 5 mM (mean 66%, SD 23%), and AG-946 50 mM (mean 95%, SD 17%, Figure 1B). The glycolytic intermediate 2,3-DPG decreased after incubation with both mitapivat and AG-946 (Figure 1C), which was further illustrated by the improved ATP/2,3-DPG ratio (Figure 1D). In line with these latter results p50 decreased significantly after incubation with mitapivat 100 mM (mean 95%, SD 2%), as well as AG-946 1 mM (mean 96%, SD 2%), AG-946 5 mM (mean 94%, SD 2%), and AG-946 50 mM (mean 95%, SD 3%, Figure 1E). The improved metabolic status and p50 was accompanied by a decreased PoS compared to vehicle in RBCs treated with mitapivat or AG-946, indicating reduced RBC sickling tendency in vitro (Figure 1F).Conclusion: Ex vivo treatment of SCD RBCs with the next-generation PKR activator AG-946 activates and stabilizes PK, decreases 2,3-DPG levels, improves the ATP/2,3-DPG ratio, improves p50 and lowers the PoS. These beneficial effects are similar to ex vivo treatment with mitapivat but, importantly, are obtained at much lower concentrations. Therefore, AG-946 may be a potent activator of PKR in SCD. Taken together, these results are the first in an ex vivo model to demonstrate that the next-generation PK activator AG-946 has a similar favorable pharmacodynamic profile to mitapivat with enhanced PK-stabilizing properties and, hence, represents a potential novel therapeutic option in addition to mitapivat for the treatment of SCD and other hemolytic anemias. [Display omitted] DisclosuresRab: Axcella Health: Research Funding; Agios Pharmaceuticals: Research Funding. Van Dijk: Axcella Health: Research Funding; Agios Pharmaceuticals: Research Funding. Kosinski: Agios Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Kung: Agios Pharmaceuticals, Inc.: Current Employment, Current holder of stock options in a privately-held company. Van Beers: Pfizer: Research Funding; RR Mechatronics: Research Funding; Novartis: Research Funding; Agios Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding. Dang: Agios Pharmaceuticals, Inc.: Current Employment, Current holder of stock options in a privately-held company. Wijk: Agios Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Axcella health: Research Funding; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Clinical Results of the Drepaglobe Trial for Sickle Cell Disease Patients

▪In sickle cell disease (SCD), the β6 Glu→Val substitution leads to sickle hemoglobin (HbS) polymerization and red blood cell (RBC) sickling. Transplantation of autologous, genetically modified hematopoietic stem/progenitor cells (HSPCs) represents a promising therapeutic option for patients lacking a compatible donor.We previously designed a lentiviral vector (βAS3 LV) expressing a potent anti-sickling βAS3 globin and demonstrated its safety and efficacy in SCD patient cells (Weber et al., 2018). In vitro and in vivo preclinical studies demonstrated the safety and efficacy of a gene therapy (GT) protocol based on the efficient transduction of plerixafor-mobilized SCD HSPCs by βAS3 LV.Based on these results a Phase 1/2 clinical trial (NCT03964792) started in January 2020. Three homozygous SCD patients (P1, P2 and P3) were recruited. Before GT, patients suffered from severe SCD symptoms that were not controlled despite of a strict adherence to the treatment. Plerixafor-mobilized HSPCs were transduced achieving a VCN of 0.9±0.2 in liquid culture, 1.6±0.3 in BFU-E and 0.8±0.2 in CFU-GM. The patients were hypertransfused to reach HbS levels <30%. After busulphan-based myeloablative conditioning, they received a drug product 6 to 8.1x 10 6 per kg.Here, for the 3 patients we report the follow-up of 18 (P1), 10 (P2) and 6 (P3) months. No drug-related severe adverse events were observed. Importantly, no sign of clonal hematopoiesis was detected by NGS sequencing performed on the graft before and after transduction. Despite of the similar VCN in the drug product, gene marking in peripheral blood mononuclear cells was variable and ranged between 0.2 and 0.6, as measured at the last follow-up (0.4 in P1, 0.6 in P2 and 0.2 in P3). These results pinpoint the difficulty to estimate the gene marking, self-renewal and engraftment potential of HSCs in the grafts.P1 and P2 clinically benefit from the GT treatment despite they presented non-severe vaso-occlusive crises (VOCs) not requiring hospitalization (two for P1 at month 6 and 14 and one in P2 at month 8 post-GT). Despite the rapid resolution of these episodes, P1 started hydroxyurea at month 10 and stopped it at month 16. P2 initiated a phlebotomy program to treat liver iron overload and decrease viscosity. Intravascular hemolysis improved in P1 and P2, as shown by a decrease in plasma hemoglobin and heme, and an increase in hemopexin (HPX). Interestingly, in P1 a mild worsening occurred at the time of VOC. In P1 and P2, total bilirubin, a marker of extravascular hemolysis, decreased post-GT. Deformability, measured using osmoscan, improved in P1 and to a lesser extent in P2; however, both still exhibited some degree of dehydration compared to normal RBCs (Fig. 1). Adhesion to thrombospondin decreased after GT with an increase during VOC in P1 or prior the VOC in P2 (Fig. 1). In both patients, markers of inflammation (e.g., C reactive protein) and reticulocyte counts decreased upon GT. An in vitro sickling assays was performed for P1 and showed significant improvement, reaching a frequency of sickling cells similar to SCD heterozygous carriers (from 88% before GT to 45% 6 months post-GT).The GT treatment was not effective in P3 due to the modest intake and rapid decline of gene modified cells.In P1 and P2, who were no longer on transfusions, HbAS3 levels correlated with the VCN (2.1 g/dl for P1 and 3.3 g/dl for P2) and the therapeutic Hb accounted for 21.5%, and 28.7% of the total hemoglobins, respectively. For P3, who remained transfusion-dependent, this frequency was <3% due to the low VCN and the presence of the transfusion-derived Hb. Notably, total Hb concentration was only 8.1 g/dl in P2 before the treatment and reached 11.4 g/dl at the last follow-up, suggesting a better survival of RBCs derived from genetically modified HSPCs. Furthermore, in P1 and P2, HbAS3 levels were significantly higher in mature RBCs compared to reticulocytes, indicating a survival advantage of βAS3 globin-expressing cells.Overall, these clinical data indicate a variable efficacy of the DREPAGLOBE GT treatment, which likely depends on the extent of gene marking achieved in HSCs in vivo and on the engraftment capability of genetically modified HSCs in SCD patients' bone marrow. Single-cell RNA-seq analysis of HSPCs and evaluation of the bone marrow niche in SCD patients will aid to define critical parameters for achieving successful outcomes in GT clinical trials for SCD. [Display omitted] DisclosuresJoseph: bluebird bio: Consultancy. El Nemer: Hemanext: Consultancy. Bartolucci: INNOVHEM: Other: Co-founder; AGIOS: Consultancy; GBT: Consultancy; Bluebird: Consultancy, Research Funding; Jazz Pharma: Other: Lecture fees; Fabre Foundation: Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Steering committee, Research Funding; F. Hoffmann-La Roche Ltd: Consultancy; Hemanext: Consultancy; Addmedica: Consultancy, Other: Lecture fees, Research Funding; Emmaus: Consultancy. Cavazzana: Smart Immune: Other: co-founder.

A reanalysis of pain crises data from the pivotal l-glutamine in sickle cell disease trial

The pivotal Endari trial in sickle cell disease showed a reduction in pain crises events. This reanalysis of the l-glutamine phase 3 trial using annual rates of pain crises, consistent with other SCD studies, supported the statistically significant outcomes of the original analysis. The observed 45% difference in the VOC rate is comparable to what was reported in other sickle cell therapeutics used to reduce the incidence of pain. The results presented in this communication are informative for clinicians evaluating treatment effects across available SCD therapeutic options based on studies that utilized VOC as the primary endpoint.

Evaluation of Longitudinal Pain Study in Sickle Cell Disease (ELIPSIS) by patient-reported outcomes, actigraphy, and biomarkers

Clinical trials in sickle cell disease (SCD) often focus on health care utilization for painful vaso-occlusive crises (VOCs). However, no objective, quantifiable pain biomarkers exist, pain is not specific to VOCs, health care utilization varies between patients, unreported at-home VOCs likely contribute to long-term outcomes, and patient-reported outcomes are seldom considered. This noninterventional, longitudinal, 6-month study aimed to develop tools to identify VOCs in SCD patients with or without health care utilization. Participants wore an actigraph device, tracking sleep and activity. Patients with SCD used an electronic patient-reported outcome (ePRO) tool to collect data on pain, medication, fatigue, and daily function. Patients self-reported when they experienced VOC pain (VOC day). Biomarkers were collected every 3 weeks (non-VOC). Self-reported VOCs triggered at-home or in-hospital blood collection. The study enrolled 37 participants with SCD; 35 completed the study. Participants reported 114 VOC events and 346 VOC days, of which 62.3% and 78.3%, respectively, were self-treated at home. The ePRO and actigraphy captured end points of pain, functionality, fatigue, activity, and sleep; each was significantly altered on VOC days compared with non-VOC days. Biomarkers collected at home or in the hospital on VOC days were significantly altered compared with non-VOC baseline values, including leukocyte-platelet aggregates, microfluidic-based blood cell adhesion, interleukin-6, C-reactive protein, interleukin-10, tumor necrosis factor-α, and thrombin–antithrombin. The Evaluation of Longitudinal Pain Study in Sickle Cell Disease (ELIPSIS) trial shows the feasibility of accurately monitoring out-of-hospital pain by using patient-reported VOC days as potential end points for clinical trials in SCD; it describes the changes in biomarkers and activity measured by actigraphy that may enable improved identification and assessment of VOCs.

Gene therapy trials for sickle cell disease halted after two patients develop cancer

Gene therapy trials for sickle cell disease halted after two patients develop cancer

A Patient-Centric Approach to Improve the Understanding of Sickle Cell Disease Using Real-World Data

Background: Sickle cell disease (SCD) comprises a group of inherited blood disorders, and is a complex, multi-system, disease. SCD is associated with a variety of clinical complications that affect multiple organ systems. These complications are driven primarily by vaso-occlusion and hemolytic anemia, and can result in end-organ damage and early death. Painful vaso-occlusive crises (VOCs) are a characteristic feature of SCD and can require healthcare intervention. Despite recent advances in the screening, management and treatment of SCD, gaps remain in our understanding of the disease in the real-world setting. These include how best to transition from pediatric to adult care and how to manage specific complications. Currently, most real-world evidence (RWE) is generated from information captured in payer databases, which is not as comprehensive as the information recorded in electronic medical records (EMRs). Despite being potentially valuable sources of real-world, clinical information, EMRs for individual patients in the USA are not centralized, often being held by multiple healthcare providers using different EMRs. This fragmented system prevents generation of clear, comprehensive RWE, both in general and for SCD specifically. Furthermore, there is a lack of harmonization between EMR companies/systems in the types of information included and how it's recorded. A separate approach that collates all available data from EMRs into a single, comprehensive record prior to RWE analysis would therefore greatly improve the accessibility of the available information and the quality of subsequent data analysis. Aims: In contrast to existing RWE, this study explores the value of collating EMRs for each patient into a single, consistently structured format, with the aim of developing richer RWE to complement existing data on SCD. It is hypothesized that the resulting longitudinal overview of each patient's care will contribute to an improved understanding of SCD in the real-world setting: firstly, by better capturing how many VOCs patients with SCD experience, with an indication of the proportion of VOCs that are being home-managed; secondly, by gaining deeper insights into the prevalence and progression of end-organ damage and any association with VOCs; and finally, by highlighting the type and site of care of SCD in the real world (eg medications, treating healthcare professional [HCP] specialties and the type of clinic visited). Study design: The study population will comprise 400 patients with SCD from the USA. Patient recruitment occurs directly via social media and indirectly through a variety of partnerships including HCPs and patient advocacy groups. To enroll, patients sign an informed consent form allowing their de-identified medical information to be shared with third-party organizations to advance SCD research. Enrolled patients gain access to their medical records via a dashboard. The key inclusion criteria are: a confirmed SCD diagnosis (irrespective of phenotype); aged ≥16 years at enrollment; and ≥1 inpatient admission for a VOC in the 12 months prior to enrollment. The key exclusion criterion is the absence of medical records. Components of EMRs collected include doctors' notes, laboratory and test results, clinical imaging and treatment records. Human-curated natural language processing and machine learning is used to extract, structure and code data from the structured sections and unstructured narrative text of the EMR. All medical records, from all visits, will be collected where possible and are expected to comprise ≥7 years of retrospective data for each patient. Results: Between 1 December 2019 and 24 June 2020, a total of 46 patients with a mean age of 36 years (SD 9.7) were enrolled. For each patient, a median of 6.8 years of data from a median of 32.5 providers were obtained. Conclusions: The evidence derived from this study aims to advance the understanding of real-world practices in the management of SCD. It may also provide further learnings regarding the prevalence of complications and any association between VOCs and end-organ damage. Generating a single, structured overview of all EMRs for each patient allows for richer insight generation and a more comprehensive analysis of RWE, compared with existing approaches. The insights gained from this RWE may inform future studies and clinical trials in SCD, with the ultimate aim of improving the quality of life of patients. Disclosures Clay: Novartis: Consultancy; GBT: Consultancy. Bailey:Novartis Pharmaceuticals Corporation: Current Employment. Drozd:F. Hoffmann-La Roche Ltd: Other: All authors received support for third party writing assistance, furnished by Scott Battle, PhD, provided by F. Hoffmann-La Roche, Basel, Switzerland.; PicnicHealth: Current Employment, Current equity holder in private company. Paulose:Novartis Pharma AG: Current Employment. Ramscar:Novartis Pharma AG: Current Employment. Mace:Roche/Genentech: Ended employment in the past 24 months; PicnicHealth: Current Employment. Wormser:Novartis Pharma AG: Current Employment, Current equity holder in publicly-traded company.

The Meaning of Informed Consent: Genome Editing Clinical Trials for Sickle Cell Disease

Background A first therapeutic target of somatic genome editing (SGE) is sickle cell disease (SCD), the most commonly inherited blood disorders, affecting more than 100,000 individuals in the United States. Advancement of SGE is contingent on patient participation in first in human clinical trials. However, seriously ill patients may be vulnerable to overestimating the benefits of early phase studies while underestimating the risks. Therefore, ensuring potential clinical trial participants are fully informed prior to participating in a SGE clinical trial is critical. Methods: We conducted a mixed-methods study of adults with SCD as well as parents and physicians of individuals with SCD. Participants were asked to complete a genetic literacy survey, watch an educational video about genome editing, complete a two-part survey, and take part in focus group discussions. Focus groups addressed topics on clinical trials, ethics of gene editing, and what is not understood regarding gene editing. All focus groups were audio-recorded, transcribed, and analyzed using conventional content analysis techniques to identify major themes. Results: Our study examined the views of SCD stakeholders regarding what they want and need to know about genome editing to make an informed decision to participate in a SGE clinical trial. Prominent themes included stakeholders’ desire to understand treatment side effects, mechanism of action of SGE, trial qualification criteria, and the impact of SGE on quality of life. In addition, some physicians expressed concerns about the extent to which their patients would understand concepts related to SGE; however, individuals with SCD demonstrated higher levels of genetic literacy than estimated by physicians. Conclusions: Designing ethically robust genome editing clinical trials for the SCD population will require, at a minimum, addressing the expressed information needs of the community through culturally sensitive engagement, so that they can make informed decisions to consider participation in clinical trials.

βT87Q-Globin Gene Therapy Reduces Sickle Hemoglobin Production, Allowing for Ex Vivo Anti-sickling Activity in Human Erythroid Cells

Lentiviral addition of βT87Q-globin, a modified β-globin with an anti-sickling mutation, is currently being used in gene therapy trials for sickle cell disease (SCD) and β-thalassemia patients. βT87Q-globin interferes with sickle hemoglobin (HbS) polymerization. Here, we generated the SCD mutation in an immortalized human erythroid cell line (HUDEP-2) to investigate the anti-sickling activity of βT87Q-globin. Sickle HUDEP-2 (sHUDEP-2) cells produced robust HbS after differentiation and sickled under deoxygenated conditions, comparable with SCD CD34+ progeny. Lentiviral transduction provided 9.5–26.8 pg/cell βT87Q-globin (R2 = 0.83) in a vector copy number (VCN)-dependent manner, resulting in a significant reduction of sickling ratios (R2 = 0.92). Interestingly, βT87Q-globin transduction markedly reduced endogenous βS-globin (R2 = 0.84) to an undetectable level (0.4–16.8 pg/cell) in sHUDEP-2 cells, as well as endogenous β-globin in human CD34+ cell-derived erythroid cells. RNA sequencing (RNA-seq) analysis with βT87Q-transduced sHUDEP-2 and human CD34+-derived cells revealed activation of inflammation- and proliferation-related programs, suggesting minimal changes in background gene expression except for βT87Q-globin expression and endogenous β/βS-globin suppression. In summary, using sHUDEP-2 and CD34+-derived cells, we demonstrated that lentiviral addition of βT87Q-globin strongly reduced endogenous β-/βS-globin expression, resulting in an anti-sickling effect. Our findings should be helpful to understand the anti-sickling effects of therapeutic genes in SCD gene therapy.

Ca2+ signalling in fibroblasts and the therapeutic potential of KCa3.1 channel blockers in fibrotic diseases.

The role of Ca2+ signalling in fibroblasts is of great interest in fibrosis-related diseases. Intracellular free Ca2+ ([Ca2+ ]i ) is a ubiquitous secondary messenger, regulating a number of cellular functions such as secretion, metabolism, differentiation, proliferation and contraction. The intermediate conductance Ca2+ -activated K+ channel KCa 3.1 is pivotal in Ca2+ signalling and plays a central role in fibroblast processes including cell activation, migration and proliferation through the regulation of cell membrane potential. Evidence from a number of approaches demonstrates that KCa 3.1 plays an important role in the development of many fibrotic diseases, including idiopathic pulmonary, renal tubulointerstitial fibrosis and cardiovascular disease. The KCa 3.1 selective blocker senicapoc was well tolerated in clinical trials for sickle cell disease, raising the possibility of rapid translation to the clinic for people suffering from pathological fibrosis. This review after analysing all the data, concludes that targeting KCa 3.1 should be a high priority for human fibrotic disease.