Nogo-a Pathway Contributes to Neural Injury and Pain in Sickle Cell Disease

Abstract Sickle cell disease (SCD) is characterized by chronic pain and bouts of extreme acute pain from vasoocclusive crises (VOC). Sickle pain has both neuropathic and inflammatory features (Tran et al., Blood 2017). Mechanisms underlying neural injury remain unknown in SCD. Neurite outgrowth inhibitor (NOGO-A/reticulon-4) and its receptor NGR1 contribute to pain, neuronal damage, and inhibition of neurite outgrowth (Hu et al., FASEB J 2019). We examined if NOGO-A pathway is activated in a sickle microenvironment and if its inhibition will ameliorate hyperalgesia in BERK sickle mice. We used Rho kinase activity (ROCK) downstream of NGR1 as a readout of activation of NOGO-A/NGR1 pathway. We observed increased expression of NOGO-A (~260%, p<0.05) and NGR1 (~180%, p<0.05) in the dorsal root ganglia, and increased NOGO-A and ROCK activity in spinal cords of sickle mice compared to control mice expressing normal human hemoglobin A. Earlier, we found that an endogenous cannabinoid, palmitoylethanolamide (PEA) inhibits spinal NOGO-A expression and ROCK activity in sickle mice (Argueta et al., ASH 2020 #225). We hypothesized that sickle microenvironment with cell-free heme and inflammation activates NOGO-A/NGR1-ROCK pathway leading to nerve injury and pain, and inhibition of this pathway will ameliorate hyperalgesia in sickle mice. Using terminally differentiated rat pheochromocytoma (PC12) cells, we simulated a sickle microenvironment with hemin (40 µM) and TNFα (1 ng/ml) (H+T). H+T elevated ROCK activity compared to vehicle (~40%, p<0.05). PEA (30 uM) and 2 µM NEP (1-40), a competitive antagonist of NGR1, attenuated H+T-induced ROCK activity (both p<0.01); co-treatment had no additive effect, indicating a common pathway. As well, siRNA (10 nM) knockdown of NGR1 reversed H+T-induced ROCK activity (p<0.001), which was equally effective with 30 µM PEA co-treatment. Functionally, treatment with 30 µM PEA or 2 µM NEP (1-40) enhanced neurite outgrowth in H+T-treated PC-12 cells (~120%, p<0.001). NEP (1-40) at 5 mg/kg reduced mechanical and cold (both ~50%, p<0.001) hyperalgesia in sickle mice compared to baseline (BL) and/or vehicle treatment. Together, these data demonstrate that NOGO-A/NGR1 pathway activation may underlie nerve injury, and inhibition of this pathway with a NGR1 antagonist or PEA promotes neurite outgrowth and reduces hyperalgesia in a sickle microenvironment. We next examined the contribution of exogenously administered and endogenously produced PEA in ameliorating hyperalgesia. Mass spectrometry revealed that spinal PEA is reduced in female (p<0.05) and male (p<0.001) sickle mice compared to age/sex-matched control mice. Exogenous PEA (i.p. 20 mg/kg/d) reduced cold avoidance over a 3-day treatment period, showing significantly more time in the cold chamber compared to BL or vehicle at 1 h, 24 h, and 72 h (p<0.05). The analgesic effect of PEA was maintained for 9 days of treatment without developing tolerance. We next increased endogenous PEA by inhibiting its degradative enzyme, N-acylethanolamine acid amidase, with ARN19702 (i.p. 3, 10, & 30 mg/kg/d), which reduced mechanical (~50%, p<0.001) and cold hyperalgesia (~40%, p<0.001) over 72 hours in a dose-dependent manner. Since hypoxia and ischemia reperfusion injury contribute to acute VOC pain, we incited hypoxia-reoxygenation (HR; 3 h @ 8% O 2, 92% N 2, followed by 1 h @ normoxia) to simulate acute VOC pain. We observed that 5-day pretreatment with PEA (i.p. 20 mg/kg/d) before HR prevented mechanical and cold hyperalgesia following HR in sickle mice. Moreover, treatment with PEA after HR incitement significantly reduced hyperalgesia for 24 h after HR compared to BL (~30%, p<0.001) and vehicle treated (~66%, p<0.001) sickle mice. NGR1 antagonism reduces spinal microglial injury/activation. Heme and TNFα have been shown to cause microglial injury in vitro, while spinal microglial activation has been demonstrated in sickle mice (Lei et al., Antioxid Redox Signal 2021). Thus, NGR1/ROCK cascade may contribute to both neuronal injury and inflammation in the central nervous system leading to neuropathic pain. Our data suggest that PEA and targeting NOGO-A pathway may prevent/reduce chronic and acute hyperalgesia in sickle mice. We speculate that interventions targeting NOGO-A pathway may prevent/reduce neuropathic pain and that PEA has the translational potential for the treatment of chronic and acute pain in SCD. Disclosures Gupta: Tautona Group: Consultancy, Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; 1910 Genetics: Other: Grantee; Grifols: Other: Grantee; SCDAA: Membership on an entity's Board of Directors or advisory committees; CSL Behring LLC: Honoraria; NIH: Other: Grantee; University of Minnestoa Foundation: Other: Philanthropic Funding; Southern California Institute for Research and Education Foundation: Other: Philanthropic Funding; Cyclerion: Research Funding; UCI Foundation: Other: Philanthropic Funding.

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A Pilot Study of Eptifibatide for Treatment of Acute Pain Episodes in Sickle Cell Disease.

Blood ◽

10.1182/blood.v120.21.2102.2102 ◽

2012 ◽

Vol 120 (21) ◽

pp. 2102-2102

Author(s):

Payal C Desai ◽

Julia Brittain ◽

Susan Jones ◽

Adam McDonald ◽

Douglas R Wilson ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Sickle Cell ◽

Acute Pain ◽

Research Funding ◽

Point Estimate ◽

Acute Chest Syndrome ◽

Cell Disease ◽

Opioid Use ◽

Advisory Committees

Abstract Abstract 2102 Background: Despite the abundant laboratory evidence of platelet activation and inflammation in sickle cell disease (SCD), the contribution of these changes to the pathogenesis of SCD remains uncertain. Patients with SCD exhibit increased platelet activation in the non-crisis, “steady state,” and further increases with acute pain episodes. In addition, levels of the inflammatory mediator, CD40 ligand (CD40L) are increased in the plasma and significantly reduced in the platelets of SCD patients compared to healthy individuals. CD40L may contribute to the pathogenesis of acute pain episodes. Despite an improved understanding of the pathophysiology of SCD, the treatment of acute pain episodes is supportive. We performed a randomized, placebo-controlled study to evaluate the safety and efficacy of eptifibatide, a synthetic peptide inhibitor of the glycoprotein (GP) IIb/IIIa receptor, in patients with SCD during acute painful episodes. Methods: In this single site placebo-controlled trial, eligible patients admitted for acute painful episodes received eptifibatide (two 180 mg/kg boluses 10 minutes apart, followed by a continuous infusion at 2 mg/kg/min for 6 hours) or placebo at a ratio of 2:1. The Post-Treatment Phase lasted for up to 7 days or until resolution of the crisis, whichever was shorter, but no less than 24 hours after discontinuation of infusion. The Follow-up Phase included safety evaluations obtained 14 to 17 days and 28 to 35 days after discontinuation of infusion. The primary outcomes were major bleeding episodes and the largest observed decrease in platelet count during the study. We also evaluated the effect of eptifibatide on the duration of acute pain episodes, pain intensity, duration of hospitalization, total opioid use and acute chest syndrome. Results: Thirteen patients (SS - 10, Sb0 - 2, SC - 1) were randomized to receive either eptifibatide (N=9; 6 females; median age - 25 years) or placebo (N=4; 3 females; median age - 31 years). One patient in the eptifibatide arm withdrew consent following completion of study drug infusion and 1 patient in the placebo arm was withdrawn early because she did not meet eligibility criteria. In the intent-to-treat analysis, there were no major bleeding episodes in either group (point estimate of difference in eptifibatide vs. placebo proportion: 0.0, 95% CI; −0.60, 0.37).There was one minor bleeding episode in a patient on the eptifibatide arm (point estimate of difference in eptifibatide vs. placebo proportion: 0.11, 95% CI: −0.502, 0.494). There was a trend for the largest decrease in platelet count to be greater in the eptifibatide arm compared to the placebo arm, although the difference was not statistically significant (Hodges-Lehman estimate of location shift for eptifibatide vs. placebo: −82, 95% CI; −281, 54). There was no significant difference in the proportion of patients with thrombocytopenia between the treatment groups (point estimate of difference in eptifibatide vs. placebo proportion: 0.11, 95% CI: −0.587, 0.495). The median time to discharge and the median time to crisis resolution were 3.0 days for both treatment arms. The median total opioid use was 400.2 morphine equivalents (ME) for the eptifibatide group and 1471 ME for the placebo group (Hodges-Lehman estimate of location shift for eptifibatide vs. placebo: −65.8, 95% CI: −2519, 1700). There was one episode of acute chest syndrome in each treatment arm. Conclusions: In this small study of SCD patients hospitalized with acute painful episodes, eptifibatide appeared to be safe, but did not improve the times to crisis resolution or hospital discharge. Eptifibatide was associated with a reduced requirement for opioid analgesics, although the difference was not statistically significant. Clinicaltrials.gov Identifier: NCT00834899. Disclosures: Parise: BD: Consultancy; Biogen-Idec: Consultancy; NIH: Research Funding; AHA: Research Funding; SCDAC-NIH: Membership on an entity's Board of Directors or advisory committees; BRI Milwaukee: Membership on an entity's Board of Directors or advisory committees. Ataga:Pfizer: Consultancy; HemaQuest Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Adventrx Pharmaceuticals: Consultancy. Off Label Use: Eptifibatide, a glycoprotein IIb/IIIa inhibitor, was evaluated as treatment for acute pain episodes in patients with sickle cell disease.

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The Effect of Crizanlizumab on the Number of Days Requiring Opioid Use for Management of Pain Associated with Vaso-Occlusive Crises in Patients with Sickle Cell Disease: Results from the Sustain Trial

Blood ◽

10.1182/blood-2020-140428 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 32-33

Author(s):

Wally R Smith ◽

Kenneth I. Ataga ◽

Santosh L. Saraf ◽

Olufolake A. Adisa ◽

Miranda Bailey ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Sickle Cell ◽

Acute Pain ◽

Research Funding ◽

Relative Reduction ◽

Cell Disease ◽

Opioid Use ◽

Advisory Committees ◽

Absolute Reduction

OBJECTIVES: Vaso-occlusion is a hallmark feature of sickle cell disease (SCD) that promotes ischemia-reperfusion injury and leads to acute pain episodes, known as vaso-occlusive crises (VOCs). VOCs are disabling and frequently impact on the ability of the patient to attend work or school and participate in activities of daily living. VOCs are the primary reason for medical facility visits amongst SCD patients and are associated with increased morbidity and mortality. The acute pain of a VOC often requires parenteral opioid administration in hospital emergency departments and inpatient units. Patients are also frequently prescribed oral opioids to aid in home management of VOCs. The development of new SCD therapies that have been shown to reduce or prevent VOCs has generated interest in their potential as opioid sparing agents. This study evaluated the effect of crizanlizumab-a humanized monoclonal antibody indicated in the US for reduction of VOCs in SCD-on opioid use for managing VOC related pain. METHODS: In this post hoc analysis, subject-level data from the SUSTAIN (NCT01895361) trial were analyzed to determine the number of days of opioid use by patients in both the 5.0 mg/kg crizanlizumab and placebo arms during the 52-week follow-up period. Opioid use captured in case report forms was retrospectively assessed. Due to the common use of "as needed" (PRN) dosing for analgesics, a decision tree was developed in conjunction with clinical advice to guide classification of the opioid as being taken or not taken on a given day based on clinically plausible assumptions. Assumptions considered dose frequency (fixed vs. PRN), route of administration (parenteral vs. oral), and concomitant medications (anti-emetics and anti-histamines). Opioid record start dates, end dates, and dose frequencies were used to determine the number of unique days during the trial that each patient had taken at least one opioid. The annualized days with opioid use was calculated for each patient by dividing their number of unique days on opioids by their duration (days) in the trial. The distribution of annualized days with opioid use was compared between patients from the 5.0 mg/kg crizanlizumab and placebo arms. Mann-Whitney U tests with p-values were used to test differences between arms. A four-step analysis was planned to incorporate an increasing number of assumptions to define whether the opioid had been taken on a given day (see footnote of Table 1). Analyses were performed primarily in the per-protocol (PP) population considering all routes of administration and parenteral use only. Outcomes in the intention-to-treat (ITT) population were also assessed. RESULTS: The PP population included 40 patients in the 5.0 mg/kg crizanlizumab arm and 41 patients in the placebo arm. A comparison of the baseline demographics (age, sex, genotype, hydroxyurea use, crisis frequency, and opioid use) showed no statistically significant differences between the two arms. Results of the final step of each analysis are presented as the primary analysis (see Table 1); results of Step 1 were considered a sensitivity analysis (not shown). The median annualized days with opioid use in the PP population was lower in the crizanlizumab arm compared with the placebo arm (absolute reduction: 4.00 days; relative reduction: 57%; p=0.162). The median annualized days with parenteral opioid use was lower in the crizanlizumab arm compared with the placebo arm (absolute reduction: 2.01; relative reduction: 50%; p=0.047). Results in the ITT population (see Table 1) and for sensitivity analyses (not shown) showed similar trends of reduced annualized days with opioid use for patients in the crizanlizumab group compared to the placebo group. CONCLUSIONS: These findings indicate that crizanlizumab, compared with placebo, may reduce the annual number of days where opioids are used to manage pain from VOCs. Importantly, the benefit was observed for parenteral and oral opioids, demonstrating clinical and patient relevance. These findings are concordant with the tendency for crizanlizumab to reduce the number of VOCs experienced by SCD patients annually; the primary finding of the SUSTAIN trial. The reduction in opioid use with crizanlizumab requires exploration in future studies, but the findings of this study translate into positive clinical and patient-relevant outcomes beyond reducing the frequency of VOCs. Disclosures Smith: Shire: Research Funding; Imara: Research Funding; Novo Nordisk: Consultancy; Ironwood: Consultancy; Pfizer: Consultancy; Incyte: Other: Investigator; Health Resources and Services Administration: Other: Investigator, Research Funding; Patient-Centered Outcomes Research Institute: Other: Investigator, Research Funding; NHLBI: Research Funding; Shire, Inc.: Other: Investigator, Research Funding; Global Blood Therapeutics, Inc.: Consultancy, Research Funding; Novartis, Inc.: Consultancy, Other: Investigator, Research Funding; Emmaeus Pharmaceuticals, Inc.: Consultancy; GlycoMimetics, Inc.: Consultancy. Ataga:Bioverativ: Honoraria, Membership on an entity's Board of Directors or advisory committees; Shire/Takeda: Research Funding; Editas Medicine: Honoraria; Global Blood Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Research Funding; Forma Therapeutics: Consultancy; Modus Therapeutics: Honoraria; Novo Nordisk: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Research Funding. Saraf:Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Advisory Boards, Speakers Bureau; Novartis, Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees; Pfizer, Global Blood Therapeutics, Novartis: Research Funding. Adisa:Novartis Pharmaceuticals Corporation: Current Employment. Bailey:Novartis Pharmaceuticals Corporation: Current Employment. Ramscar:Novartis Pharma AG: Current Employment. Bonner:Eversana: Current Employment. Brown:Eversana: Current Employment. Pastor:Eversana: Current Employment.

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Clinical and Biomarker Predictors for Avascular Necrosis in Sickle Cell Disease

Blood ◽

10.1182/blood-2021-147829 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 3091-3091

Author(s):

Michael Rabaza ◽

Maria Armila Ruiz ◽

Liana Posch ◽

Faiz Ahmed Hussain ◽

Franklin Njoku ◽

...

Keyword(s):

Risk Factors ◽

Sickle Cell Disease ◽

Board Of Directors ◽

Avascular Necrosis ◽

Sickle Cell ◽

Research Funding ◽

Medical Attention ◽

Cell Disease ◽

Advisory Committees ◽

Early Management

Abstract Introduction Sickle cell disease (SCD) affects 1 in 365 African Americans and approximately 25 million people world-wide. A common skeletal system complication is avascular necrosis (AVN), which can cause substantial pain and a reduced quality of life. While early management of AVN is focused on increasing range of motion with physical therapy and pain relief, there are no clear predictors for who is more likely to develop AVN and earlier institution of these preventive measure could help decrease disease progression. Vascular endothelial growth factor (VEGF) is a biomarker of endothelial injury and may indicate reduced vascular supply to the femoral or humeral head. Here we describe potential risk factors and biologic pathways for AVN in SCD, as understanding these may lead to improvements in future monitoring, early detection, and early intervention practices. Methods We investigated clinical and laboratory risk factors associated with AVN in a cohort of 435 SCD patients from our center. Blood samples, clinical, and laboratory data were collected at the time of enrollment during a clinic visit. Genotyping for alpha thalassemia was performed by PCR and the serum concentration of VEGF was measured by ELISA. AVN status was confirmed by review of the medical record and available imaging. We conducted a cross-sectional analysis comparing categorical and linear variables by AVN status using the chi-square and Kruskal-Wallis test, respectively. The independent association of the clinical and laboratory variables with AVN status was determined by logistic regression analysis. The initial model included variables with a P-value < 0.1 on univariate analysis and the final model was ascertained by stepwise forward and backward selection. Median values and interquartile range (IQR) are provided. Results The median age of the cohort was 32 (IQR, 24 - 43) years, 57% (250/435) were female, and 46% (198/435) were on hydroxyurea. AVN was observed in 34% (149/435) of SCD patients. SCD patients with AVN were older, had more frequent vaso-occlusive crises requiring medical attention, and had a higher body mass index (Table I) (P ≤ 0.002). We measured VEGF in 241 of the SCD patients with serum samples available at the time of enrolment. Serum VEGF concentrations trended higher in SCD patients with versus without AVN (420 vs. 359 pg/mL, respectively; P = 0.078). In the multivariate analysis model, AVN was independently associated with increased number of vaso-occlusive crises (OR 1.1, 95% CI: 1.0 - 1.14; P = 0.02), AST concentration (natural log OR 0.5, 95% CI: 0.2 - 0.9; P = 0.03), VEGF concentration (natural log OR 1.4, 95% CI: 1.0 - 1.9; P = 0.047), and tobacco use (OR 1.9, 95% CI: 0.9 - 3.7; P = 0.078). Discussion In conclusion, we demonstrate a high prevalence of AVN in an adult cohort of SCD patients. The presence of AVN was independently associated with a greater frequency of vaso-occlusive pain episodes, which may demonstrate a shared pathophysiology between AVN and vaso-occlusion that merits further investigation. We demonstrate that serum VEGF concentrations are higher in SCD patients with AVN and may be a clinical tool to identify those at high-risk and for earlier intervention for this complication. Figure 1 Figure 1. Disclosures Gordeuk: Modus Therapeutics: Consultancy; Novartis: Research Funding; Incyte: Research Funding; Emmaus: Consultancy, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; CSL Behring: Consultancy. Saraf: Pfizer: Research Funding; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding.

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Sex Based Differences in Sickle Cell Disease

Blood ◽

10.1182/blood-2020-140896 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 37-37

Author(s):

Rita V Masese ◽

Dominique Bulgin ◽

Mitchell Knisely ◽

Liliana Preiss ◽

Eleanor Stevenson ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Sickle Cell ◽

Research Funding ◽

Categorical Variables ◽

Continuous Variables ◽

Cell Disease ◽

Advisory Committees ◽

Blood Institute ◽

National Heart Lung

Introduction Sickle cell disease (SCD) is the most common inherited blood disorders in the United States. The disease predominantly affects African Americans with 1 out of every 365 individuals born with SCD. The disease is characterized by vascular inflammation and vaso-occlusion leading to numerous complications and multi-organ dysfunction. Previous studies have shown women with SCD tend to outlive their male counterparts. Other than the increased life expectancy, sex-based clinical outcome differences in SCD remain largely unknown. To better characterize sex-based differences in SCD, we assessed sociodemographic characteristics, pain, treatment characteristics, laboratory measures and complications among males and females currently enrolled in the Sickle Cell Disease Implementation Consortium (SCDIC) registry. Methods The SCDIC consists of eight academic and comprehensive SCD centers, and one data-coordinating center that received funding from the National Heart Lung and Blood Institute to improve outcomes for individuals with SCD. Participants were eligible for the enrollment in the SCDIC registry if they were 15 to 45 years of age and had a confirmed diagnosis of SCD. Participants were excluded if they had sickle cell trait or had a successful bone marrow transplant. Enrolled participants completed surveys. Data were also abstracted from the participants' medical records. Data were entered into a REDCap database and analyzed using SAS version 9.4 (SAS Institute; Cary, NC). Categorical variables were presented as frequencies and percentages, continuous variables were presented as medians and interquartile ranges (IQR) or means and standard deviations. Categorical variables were analyzed using Chi-Square or Fisher exact tests when appropriate. Continuous variables were compared using the Mann-Whitney U test or independent sample t-tests depending on the distribution. A two-sided p-value less than 0.05 was deemed significant. Results A total of 2,124 participants were included in the study. The mean (SD) age of our participants was 27.8 (7.9) years. Almost all (95.6%) were Africa American, female (56%) and had hemoglobin SS (68.2%) SCD genotype. More males (55.4 % vs. 44.6%, p <0.0001) were taking hydroxyurea. Females had significantly worse reports of pain frequency and severity (p=0.0002 and <0.0001 respectively), more vaso-occlusive episodes (p=0.01) and a higher occurrence of 3 or more hospital admissions in the past year (30.9 % vs. 25.5, p= 0.03). Males had significantly more skin ulcers and respiratory, musculoskeletal, genitourinary and cardiovascular complications while females had more anxiety, depression and autoimmune conditions. Males also had significantly higher creatinine, blood urea nitrogen, albumin and liver enzymes (alkaline phosphatase, aspartate and alanine aminotransferases). Females had higher fetal hemoglobin levels with and without hydroxyurea use. There were no statistical differences in ethnicity, marital and employment status. Conclusion Key differences in SCD presentation and occurrence of complications exist among males and females. Females had higher rates of depression and anxiety while males had more chronic end-organ complications that are life threatening. Our findings emphasize the need for stratification of data analysis by sex in future SCD studies. Disclosures Hankins: Global Blood Therapeutics: Consultancy, Research Funding; National Heart, Lung, and Blood Institute: Honoraria, Research Funding; LINKS Incorporate Foundation: Research Funding; American Society of Pediatric Hematology/Oncology: Honoraria; MJH Life Sciences: Consultancy, Patents & Royalties; UptoDate: Consultancy; Novartis: Research Funding. Treadwell:UpToDate: Honoraria; Global Blood Therapeutics: Consultancy. King:Tioma Therapuetics: Consultancy; WUGEN: Current equity holder in private company; RiverVest: Consultancy; Celgene: Consultancy; Cell Works: Consultancy; Incyte: Consultancy; Magenta Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bioline: Consultancy; Novimmune: Research Funding; Amphivena Therapeutics: Research Funding. Gordeuk:CSL Behring: Consultancy, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; Imara: Research Funding; Ironwood: Research Funding; Novartis: Consultancy. Kanter:bluebird bio, inc: Consultancy, Honoraria; SCDAA Medical and Research Advisory Board: Membership on an entity's Board of Directors or advisory committees; AGIOS: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy; Sanofi: Consultancy; Medscape: Honoraria; Guidepoint Global: Honoraria; GLG: Honoraria; Jeffries: Honoraria; Cowen: Honoraria; Wells Fargo: Honoraria; NHLBI Sickle Cell Advisory Board: Membership on an entity's Board of Directors or advisory committees; BEAM: Membership on an entity's Board of Directors or advisory committees. Glassberg:Eli Lilly and Company: Research Funding; Pfizer: Research Funding; Global Blood Therapeutics: Consultancy. Shah:Bluebird Bio: Consultancy; Novartis: Consultancy, Research Funding, Speakers Bureau; Global Blood Therapeutics: Consultancy, Research Funding, Speakers Bureau; CSL Behring: Consultancy; Alexion: Speakers Bureau.

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Improvement in the Clinical Global Impression of Change with Voxelotor in Patients with Sickle Cell Disease in the Phase 3 HOPE Trial

Blood ◽

10.1182/blood-2020-137121 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 5-6

Author(s):

Wally R Smith ◽

Jane S. Hankins ◽

Miguel R Abboud ◽

Ze Cong ◽

Jonathan Sorof ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Clinical Global Impression ◽

Research Funding ◽

Cell Disease ◽

Publicly Traded ◽

Advisory Committees ◽

Global Impression Of Change ◽

Study Participants ◽

The Impact

Background: Patients with sickle cell disease (SCD) experience varied salient symptoms that impact their health-related quality of life, which incorporates illness severity, their level of distress and other aspects of impairment, and the impact of the illness on functional status. SCD symptoms may begin at an early age, and their severity varies over time and between patients. Although detection of changes in patients' self-assessed symptoms may be obfuscated by their lifelong symptoms, treating physicians with SCD expertise may be able to detect changes in a patient's status given their experience in treating the diverse symptoms across multiple patients. We evaluated the longitudinal impact of voxelotor (Oxbryta®) in the HOPE study using the single-item Clinical Global Impression of Change (CGI-C), a validated clinician-reported outcome analogous to the commonly used Patient Global Impression of Change (PGI-C), which provides expert clinical impressions that transcend symptom checklists. Methods: In the randomized, placebo-controlled, double-blinded HOPE study, participants with SCD aged 12 to 65 years were randomized to receive voxelotor (1500 mg or 900 mg dose administered orally, once daily) or placebo. Study participants had a hemoglobin (Hb) level 5.5 to 10.5 g/dL at enrollment and 1 to 10 vaso-occlusive crises in the past 12 months at screening. Clinicians were blinded to treatment assignment and to all central laboratory measures (eg, hematological parameters) throughout the 72-week study period. Clinicians rated the CGI-C at 24 and 72 weeks from baseline. CGI-C ratings used a 7-point scale ("very much improved," "moderately improved," "minimally improved," "no change," "minimally worse," "moderately worse," and "very much worse"). CGI-C outcomes were stratified by baseline Hb levels and baseline markers of hemolysis to identify measures predictive of assessment outcomes. Results: Trends of improvement from baseline in overall clinical status with voxelotor 1500 mg, as assessed by CGI-C scores, were observed as early as week 24. At week 72, patients receiving voxelotor 1500 mg were more often rated by the clinician as "very much improved" or "moderately improved" (74%; 39 of 53) compared with those who received placebo (47%; 24 of 51) (P<0.01, Figure 1). CGI-C score improvement was consistently greater in participants treated with voxelotor compared with placebo regardless of baseline Hb. Greater proportions of participants were rated "very much improved" or "moderately improved" with voxelotor 1500 mg than placebo regardless of baseline hemolysis markers (indirect bilirubin, percentage reticulocytes, absolute reticulocyte count). Conclusions: Treatment with voxelotor 1500 mg resulted in improved clinician-reported patient outcomes, as assessed using the CGI-C. Greater proportions of participants were rated "very much improved" or "moderately improved" regardless of baseline Hb levels and baseline markers of hemolysis. The CGI provides an overall clinician-determined summary measure that takes all available information into account, including the patient's history, psychosocial circumstances, symptoms, and behavior, as well as the impact of symptoms on the patient's ability to function. Therefore, a tool that provides a holistic assessment of a patient's well-being may be complementary in capturing changes in a patient's status, considering the substantial interpatient and intrapatient variability in SCD symptomatology. CGI-C assessments are being included in ongoing studies of voxelotor. Disclosures Smith: Emmaeus Pharmaceuticals, Inc.: Consultancy; Novartis, Inc.: Consultancy, Other: Investigator, Research Funding; Global Blood Therapeutics, Inc.: Consultancy, Research Funding; Shire, Inc.: Other: Investigator, Research Funding; NHLBI: Research Funding; Patient-Centered Outcomes Research Institute: Other: Investigator, Research Funding; Health Resources and Services Administration: Other: Investigator, Research Funding; Incyte: Other: Investigator; Pfizer: Consultancy; Ironwood: Consultancy; Novo Nordisk: Consultancy; Imara: Research Funding; Shire: Research Funding; GlycoMimetics, Inc.: Consultancy. Hankins:American Society of Pediatric Hematology/Oncology: Honoraria; UptoDate: Consultancy; Novartis: Research Funding; MJH Life Sciences: Consultancy, Patents & Royalties; LINKS Incorporate Foundation: Research Funding; National Heart, Lung, and Blood Institute: Honoraria, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding. Abboud:Novartis: Consultancy, Honoraria, Research Funding; Global Blood Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Crispr Therapeutics: Membership on an entity's Board of Directors or advisory committees; Novo Nordisk: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Other: Travel support; Eli Lilly: Research Funding; Modus Pharmaceuticals: Research Funding. Cong:Global Blood Therapeutics: Current Employment, Current equity holder in publicly-traded company. Sorof:Global Blood Therapeutics: Current Employment, Current equity holder in publicly-traded company. Gray:Global Blood Therapeutics: Current Employment, Current equity holder in publicly-traded company. Hoppe:Global Blood Therapeutics: Current Employment, Current equity holder in publicly-traded company. Telfer:Global Blood Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Terumo: Honoraria; Pfizer: Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Honoraria, Research Funding; ApoPharma: Membership on an entity's Board of Directors or advisory committees.

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Sickle-Cell Disease Patients' Attitudes Towards Their Treatment with Hydroxycarbamide

Blood ◽

10.1182/blood-2019-125673 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 1013-1013

Author(s):

Frédéric Galactéros ◽

Ersi Voskaridou ◽

Anoosha Habibi ◽

Giovanna Cannas ◽

Laure Joseph ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Sickle Cell ◽

Research Funding ◽

Fetal Hemoglobin ◽

Treatment Discontinuation ◽

Cell Disease ◽

Advisory Committees

Hydroxyurea (HU) is approved in the EU and USA for prevention of vaso-occlusive crises (VOC) including acute chest syndromes (ACS) in patients over 2 years with sickle-cell disease (SCD). The major benefits of HU in SCD are directly related to its abilities to increase HbF, decrease sickling of red blood cells and hemolysis, leading to reduction of vaso-occlusive episodes, need for blood transfusions and consequently reduction of morbidity and mortality. Adherence to the treatment is paramount for effectiveness, but in spite of proven benefits, barriers to adherence persist.[1] ESCORT-HU study (European Sickle Cell Disease COhoRT - HydroxyUrea), is a multicentric, prospective, non-interventional European study designed to evaluate the safety profile of HU in real life. Patients were enrolled from January 2009 to June 2017 with a follow-up of up to 10 years. All interruptions and resumptions of HU treatment exceeding 15 days were recorded in this study. We hereby present the analysis of the group of patients who self-discontinued HU at least once during the study before informing their caregiver, with a view to identify potential barriers to long-term adherence. In total, 1906 patients were enrolled in ESCORT-HU from 63 centers in France, Germany, Greece and Italy. Of these, 619 patients (32%) stopped HU for over 15 days at least once, and around a third (11% of all patients) were due to patient's will. The mean duration of HU treatment before the first discontinuation was 4.8 ± 5.1 years. Data are summarized in table 1. Compared to the rest of the cohort, the 'treatment discontinuation' group had similar distribution by gender and indication for HU prescription, but a higher proportion of adults stopped HU more than 15 days. It is notable that the proportion of patients with SC genotype was higher in the 'treatment discontinuation' group (4.5% vs 1.7%). The patients in the 'treatment discontinuation' group had more frequent SCD symptoms before enrolment in the study (table 2). Hematological and clinical improvement compared to the baseline was observed in both groups. However, average mean Corpuscular Volume (MCV) and Fetal Hemoglobin percentage (HbF%) were lower and mean percentages of patients with SCD symptoms were higher over the three years of follow-up in the 'treatment discontinuation' group, suggesting that HU daily dose was insufficient (table 2). Sixty patients have no treatment resumption date reported which suggest a permanent interruption of their treatment. Among them 32% preferred to switch to another HU medicinal product and 13% have safety issue (table 3). Understanding and managing self-discontinuation of HU before taking medical advice is challenging for the physician. It is tempting to speculate that it may be due, at least in part, to lack of effectiveness potentially due to an underdosage of the treatment. Resistance to the treatment may also be suggested based on past literature data revealing a great variability in the response (determined by HbF%) to HU therapy. There is evidence that genetic modifiers affect individual response to HU.[2],[3] Finally, weariness from long-term use may also explain the patient's wish to discontinue HU. But treatment at optimal effective should be the primary goal of caregivers. [1]Smaldone A., Manwani D., Green NS, Greater number of perceived barriers to hydroxyurea associated with poorer health-related quality of life in youth with sickle cell disease, Pediatr Blood Cancer. 2019 [2] Steinberg MH, Voskaridou E, Kutlar A, Loukopoulos D, Koshy M, et al. (2003). Concordant fetal hemoglobin response to hydroxyurea in siblings with sickle cell disease. Am J Hematol 72: 121-126 [3] Ware RE, Despotovic JM, Mortier NA, Flanagan JM, He J, et al. (2011) Pharmacokinetics, pharmacodynamics, and pharmacogenetics of hydroxyurea treatment for children with sickle cell anemia. Blood 118: 4985-4991 Disclosures Galactéros: Addmedica: Membership on an entity's Board of Directors or advisory committees. Voskaridou:Celgene Corporation: Consultancy, Research Funding; Protagonist: Research Funding; Genesis: Consultancy, Research Funding; Acceleron: Consultancy, Research Funding; Addmedica: Membership on an entity's Board of Directors or advisory committees. Cannas:Addmedica: Membership on an entity's Board of Directors or advisory committees.

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Effects of BCL11A Shmir-Induced Post-Transcriptional Silencing on Distributions of HbF in Single-RBCs and Reticulocytes

Blood ◽

10.1182/blood-2021-150186 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 967-967

Author(s):

Nicolas Hebert ◽

Erica B. Esrick ◽

Myriam Armant ◽

Christian Brendel ◽

Marioara Felicia Ciuculescu ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Sickle Cell ◽

Research Funding ◽

Insertion Site ◽

Fetal Hemoglobin ◽

Fold Increase ◽

Advisory Board ◽

Cell Disease ◽

Advisory Committees

Abstract NH and EE equally contributed. ADW and PB co-signed. The expression of fetal hemoglobin (HbF) is one of the main targets of sickle cell disease treatment, as it inhibits the polymerization of hemoglobin S. The hypothesis of an inhibitory threshold of HbF per red blood cell (RBC) has been suggested, 1 although not well defined, as the overall percentage of HbF does not reflect the heterogeneous distribution of HbF per cell. Likewise, the qualitative analysis of RBCs containing HbF, called F cells, is neither reproducible nor clinically interpretable, due to low expression. 2 We have developed a technique for measuring the amount of HbF per cell, to determine thresholds of HbF expression per RBC correlated with clinical and biological effects. 2 Among genes controlling its expression, BCL11A has a major repressive effect on the expression of gamma globin/HbF during the fetal to adult hemoglobin switch. Post-transcriptional silencing of BCL11A, using lentivirus expression of a shRNA embedded in a microRNA architecture (shmiR) to re-activate γ-globin expression, is safe and demonstrates high levels of %HbF in a pilot clinical study (NCT 03282656). 3 Here, we show the quantitative measurement of HbF per RBC and reticulocyte. Methods: During patient follow-up, HbF quantification per single cell RBC was performed using a fluorescent HbF antibody. 2 Addition of an anti-CD71 fluorescent antibody allowed selection of reticulocyte sub-populations for determining their HbF content. Fold-increase in percentage of RBC versus percentage of reticulocyte were calculated. Kinetics of HbF/RBC and HbF/Reticulocyte were modeled using mixed effects polynomial linear regression to account for the correlation between repeated data over time. Results: With a median follow-up of 15 months [12-20] after gene transfer, figure 1 shows the mathematical modeling of single-RBC HbF measurement representing RBC percentage containing at least 2, 4, 6, 8 and 10 pg of HbF. Percentage of RBC above each threshold was higher compared to 14 hydroxyurea treated patients for 6 months. Figure 2 shows fold increase between reticulocytes and RBCs with same thresholds of HbF/cell. For low thresholds, RBCs were found in same percentage as reticulocytes whereas RBCs containing increasing levels of HbF were found in higher percentage than reticulocytes, until 6pg/cell showing a clear selective advantage for red cells with a threshold ≥ 6pg/cell of HbF. Figure 3 shows different kinetics of HbF increase according to two different transduction strategies with 2 enhancers in patients 2-4 compared to one enhancer in patients 6-8. Conclusion: BCL11A down-regulation in six clinical trial subjects was associated with an in vivo selection process RBCs with ≥ 6pg HbF per cell attained with different engraftment kinetics, depending on transduction processes, and ultimately stable high level and broadly distributed HbF. 1 Steinberg MH, Chui DH, Dover GJ, Sebastiani P, Alsultan A. Fetal hemoglobin in sickle cell anemia: a glass half full? Blood. 2014 Jan 23;123(4):481-5. 2 Hebert N, Rakotoson MG, Bodivit G, et al. Individual red blood cell fetal hemoglobin quantification allows to determine protective thresholds in sickle cell disease. Am. J. Hematol. 3 Esrick EB, Lehmann LE, Biffi A, et al. Post-Transcriptional Genetic Silencing of BCL11A to Treat Sickle Cell Disease. N. Engl. J. Med. 2021;384(3):205-215. Figure 1 Figure 1. Disclosures Esrick: bluebird bio: Consultancy. Audureau: GBT: Honoraria. Higgins: Sebia, Inc.: Honoraria; Danaher Diagnostics: Consultancy. Williams: BioMarin: Membership on an entity's Board of Directors or advisory committees, Other: Insertion Site Advisory Board; Geneception: Membership on an entity's Board of Directors or advisory committees, Other: Scientific Advisory Board; Emerging Therapy Solutions: Membership on an entity's Board of Directors or advisory committees, Other: Chief Scientific Chair; Beam Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Scientific Advisory Board; Alerion Biosciences: Other: Co-founder (now licensed to Avro Bio, potential for future milestones/royalties); Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Steering Committee, Novartis ETB115E2201 (eltrombopag in aplastic anemia). Advisory fees donated to NAPAAC.; Orchard Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Membership on a safety advisory board (SAB): SAB position ended 05/20/2021. Co-founder , Patents & Royalties: Potential for future royalty/milestone income, X-SCID. Provided GMP vector for clinical trial, Research Funding; bluebird bio: Membership on an entity's Board of Directors or advisory committees, Other: Insertion Site Analysis Advisory Board, Patents & Royalties: BCH licensed certain IP relevant to hemoglobinopathies to bluebird bio. The current license includes the potential for future royalty/milestone income. Bluebird has indicated they will not pursue this as a clinical program and BCH is negotiating return of, Research Funding. Bartolucci: AGIOS: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Steering committee, Research Funding; Jazz Pharma: Other: Lecture fees; Emmaus: Consultancy; Addmedica: Consultancy, Other: Lecture fees, Research Funding; INNOVHEM: Other: Co-founder; Hemanext: Consultancy; GBT: Consultancy; Bluebird: Consultancy, Research Funding; F. Hoffmann-La Roche Ltd: Consultancy; Fabre Foundation: Research Funding.

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Risk of Hospitalization for Vaso-Occlusive Episode in Patients with Sickle Cell Disease after out-Patient Exposure to Systemic Corticosteroids

Blood ◽

10.1182/blood-2021-151307 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 2048-2048

Author(s):

Ondine Walter ◽

Pierre Cougoul ◽

Julien Maquet ◽

Pablo Bartolucci ◽

Maryse Lapeyre-Mestre ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Sickle Cell ◽

Research Funding ◽

Cell Disease ◽

National Health Insurance System ◽

Advisory Committees ◽

Systemic Corticosteroids ◽

Increased Risk ◽

Case Period

Abstract Introduction : Sickle cell disease (SCD) is an inherited disorder which affects 300,000 newborns per year. Vaso-occlusive episodes (VOEs) cause an important morbi-mortality and a decreased quality of life in patients with SCD. Some risk factors of VOE are well known, like infection, cold exposure, stress, pulmonary diseases and dehydration. Exposure to systemic corticosteroids has been suspected to increase the occurrence of VOEs in few case reports or series. However, no comparative study has been conducted to demonstrate this risk which is still debated, resulting in discrepancies among guidelines on SCD management. This study aimed to assess the risk of hospitalization for VOE associated with out-hospital exposure to systemic corticosteroids in patients with SCD in France. Methods : Data source was the French national health insurance system database, named SNDS (Système National des Données de Santé) between 2010 and 2018. The SNDS links sociodemographic, out- and in-hospital data for the entire French population (>66 million inhabitants). The study population consisted in all patients with SCD with at least one hospitalization for VOE during the study period, identified with a primary discharge diagnosis of VOE (D57.0 code of the international classification of disease, 10 th version; positive predictive value: 98.6%). All genotypes (homozygous SS-SCD and double-heterozygous SCD) were included. Because we assessed out-hospital exposure to corticosteroids, patients hospitalized during the three months before the first VOE were excluded. We performed a case-case-time-control study (Figure 1). This self-controlled design results in self-adjustment for time-independent confounders, including genotype. The outcome was the first hospitalization for VOE. The exposure to oral and injectable corticosteroids, identified using out-hospital reimbursement data, was assessed during a case period (28 days before the outcome) compared to the exposure during a control period (28 days, starting 84 days before the outcome). The same comparison was made among future cases (matched patients hospitalized for VOE the year after the given case), in order to adjust for the trend of exposure to corticosteroids (calendar variations of corticosteroid exposure). Results : Overall, 5,151 cases of VOEs were included in the main analysis. Median age at first VOE was 16.9 years; 317 (6.2%) patients were exposed to corticosteroids during the case period. In the main analysis, corticosteroid exposure was significantly associated with the occurrence of hospitalizations for VOEs: adjusted Odds Ratio (aOR): 3.81, 95% confidence interval (95% CI): 2.44 to 5.61. In patients exposed to hydroxyurea, the aOR was 2.61, 95% CI: 1.07 to 6.39, compared with an aOR of 4.00, 95% CI: 2.53 to 6.30 in unexposed patients. In the subgroup analysis by age, the aOR was 2.81, 95% CI: 1.49 to 5.30 in children, and 4.45, 95% CI: 2.37 to 8.37 in adults. The results were consistent in all sensitivity analyses. Conclusion : This study showed an association between outpatient exposure to systemic corticosteroids with an increased risk of hospitalization for VOE, in both adults and children. Hydroxyurea may reduce this risk in adults. Figure 1 Figure 1. Disclosures Bartolucci: GBT: Consultancy; Emmaus: Consultancy; Fabre Foundation: Research Funding; AGIOS: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Steering committee, Research Funding; Jazz Pharma: Other: Lecture fees; INNOVHEM: Other: Co-founder; Bluebird: Consultancy, Research Funding; F. Hoffmann-La Roche Ltd: Consultancy; Hemanext: Consultancy; Addmedica: Consultancy, Other: Lecture fees, Research Funding. Moulis: Argenx: Membership on an entity's Board of Directors or advisory committees; Sobi: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Grifols: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding.

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Validation of BCL11A As Therapeutic Target in Sickle Cell Disease: Results from the Adult Cohort of a Pilot/Feasibility Gene Therapy Trial Inducing Sustained Expression of Fetal Hemoglobin Using Post-Transcriptional Gene Silencing

Blood ◽

10.1182/blood-2019-132745 ◽

2019 ◽

Vol 134 (Supplement_2) ◽

pp. LBA-5-LBA-5 ◽

Cited By ~ 8

Author(s):

Erica B. Esrick ◽

Maureen Achebe ◽

Myriam Armant ◽

Pablo Bartolucci ◽

Marioara Felicia Ciuculescu ◽

...

Keyword(s):

Gene Therapy ◽

Sickle Cell Disease ◽

Board Of Directors ◽

Research Funding ◽

Lentiviral Vector ◽

Cell Disease ◽

Advisory Committees ◽

Cd34 Cells ◽

F Cells ◽

Post Infusion

BCL11A regulates the fetal-adult hemoglobin switch by repressing expression at the gamma (γ)-globin locus (Sankaran et al., Science, 2008), and thus it represents an appealing therapeutic target for sickle cell disease (SCD). BCH-BB694 is a lentiviral vector (LVV) encoding a shRNA targeting BCL11A embedded in a microRNA scaffold (shmiR) allowing erythroid-specific knockdown to induce γ-globin expression and concomitantly and coordinately repress β-sickle globin expression (Brendel et al. JCI, 2016). In a pilot and feasibility gene therapy study we are evaluating the safety of infusion of BCH-BB694-transduced autologous CD34+ cells in patients with severe SCD. The study is an IND enabled and IRB approved open label, non-randomized, single center trial (NCT 03282656). We report here data from the full adult cohort which has completed enrollment with > 6 months of follow up in all patients. The adult cohort included three patients >/= 18 years old. Autologous CD34+ cells were collected by plerixafor mobilization and then transduced ex vivo with the BCH-BB694 shmiR lentiviral vector. Cell doses and vector copy number (VCN) are shown in the Table. After testing and release, gene modified cells were infused into subjects who had received busulfan conditioning. There were no Grade 3 or 4 AEs associated with mobilization, collection or infusion. All three adults (age 21-26 years old) demonstrated neutrophil engraftment on day +22 with adverse events consistent with busulfan conditioning. These patients are now 7, 9, and 17 months post infusion. One subject resumed red cell transfusions at 3 months due to pre-existing moyamoya using a pre-defined conservative trigger value of 40% sickle Hb in whole blood and will be detailed separately. There have been no adverse events related to the gene therapy product. VCN has been stable in bone marrow (BM) and peripheral blood (PB) in all cell lineages during the length of the study, with the latest time point studied at 15 months (BCL002) and ranged from 0.45-2.85 copies per cell in erythroid progenitor cells. BCL11A protein levels evaluated by immunoblot in subject BCL002 at 30 days (PB) and 6 months (BM) post-infusion showed highly effective and selective knockdown of BCL11A in erythroid progenitors with no reduction in BCL11A expression in B lymphoid cells. The number of HbF-containing cells (F cells) was assessed by flow cytometry and the kinetics of F cell production was remarkably similar in all subjects. The two untransfused subjects (BCL002 and BCL004) produced 70% F-cells in PB at 3 and 5 months, which has remained stable until the last point assayed (15 months and 7.5 months, respectively) (table). Calculated average HbF per F cell was >10pg in all subjects (table) and quantitative single cell HbF flow analysis showed the majority of F cells had >4pg F/cell, a level that is believed to prevent sickling under physiological oxygen saturation (Rakotoson et al., ASH 2017). In both untransfused subjects, total Hb remained stable with evidence of reduced hemolysis by reticulocyte count (slightly elevated) and LDH (normal in one subject, slightly elevated in the other). At the 3-month timepoint before re-starting transfusions, the subject with moyamoya (BCL003) had a pre-transfusion Hb of 11 g/dL with 76% of non-transfused cells containing on average 17pg F/F cell. For all subjects, we estimated the fraction of RBCs containing significant Hb sickle polymers and the amount of polymer in each sickled RBC at physiologic oxygen tension (where 50% of monomeric hemoglobin was oxygen saturated, or the P50) (Di Caprio et al. PNAS 2019, in press). The results for all 3 subjects in this adult cohort showed fewer RBCs with significant Hb polymer than two hydroxyurea-responsive treated comparators and significantly less Hb polymer per sickled RBC than a third highly responsive hydroxyurea-treated comparator. In conclusion, these data demonstrate successful and sustained engraftment in three adult patients treated with LVV-delivered shmiR technology targeting BCL11A. Early results suggest an acceptable safety profile, validation of BCL11A as effective target for HbF induction in humans with high numbers of F cells in circulation containing high levels of HbF per F cell, and mitigation of cellular pathology of SCD. Disclosures Achebe: Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees; Pharmacosmos: Membership on an entity's Board of Directors or advisory committees; Fulcrum Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Membership on an entity's Board of Directors or advisory committees. Bartolucci:Novartis: Membership on an entity's Board of Directors or advisory committees; AddMedica: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; HEMANEXT: Membership on an entity's Board of Directors or advisory committees; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees. Heeney:AstraZeneca: Research Funding; Micelle Biopharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Research Funding; Novartis: Consultancy, Research Funding; Ironwood / Cyclerion: Research Funding; Vertex / Crisper Therapeutics: Other: Data Safety Monitoring Board. Higgins:Sanofi: Consultancy, Research Funding. Nikiforow:Kite/Gilead: Honoraria; Novartis: Honoraria; NKarta: Honoraria. Wood:Sanofi: Consultancy, Research Funding. Williams:Alerion Biosciences: Other: Co-founder; Novartis: Membership on an entity's Board of Directors or advisory committees; Orchard Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Co-founder, Patents & Royalties: Potential for future royalty/milestone income, X-SCID., Research Funding; bluebird bio: Patents & Royalties: Licensed certain IP relevant to hemoglobinopathies to bluebird bio. Received payment in the past bluebird bio through a BCH institutional licensing agreement and there is a potential for future royalty/milestone income from this agreement., Research Funding.

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Predictive Factors for Survival in Sickle Cell Disease: A Cohort Study Using Etendard Data

Blood ◽

10.1182/blood-2018-99-113767 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 7-7

Author(s):

Laurent Savale ◽

Gylna Loko ◽

François Lionnet ◽

Bernard Maitre ◽

Anoosha Habibi ◽

...

Keyword(s):

Overall Survival ◽

Cohort Study ◽

Sickle Cell Disease ◽

Board Of Directors ◽

Transthoracic Echocardiography ◽

Research Funding ◽

Cell Disease ◽

Advisory Committees ◽

Group A ◽

Group B

Abstract Introduction The prospective ETENDARD study (NCT00434902) evaluated 398 outpatients with sickle cell disease (SCD) enrolled between February 2007 and March 2009 at referral centers in France. All patients were homozygous for hemoglobin S or had Sβ0 thalassemia. This study estimated the prevalence of pulmonary hypertension (PH) related to SCD to be 6%, based on the presence of a tricuspid regurgitation velocity (TRV) ≥2.5 m/s and a mean pulmonary arterial pressure (mPAP) measured by right-sided heart catheterization (RHC) ≥25 mmHg (Parent et al, New Engl J Med 2011). The long-term prognostic value of TRV≥2.5 m/s according to the level of mPAP measured by RHC has not been clearly established. Methods Using updated 10-year follow up data from the ETENDARD cohort study, we analyzed the overall survival of patients according to their TRV/mPAP status, as follows: patients with a TRV<2.5 m/s (group A), patients with a TRV≥2.5 m/s and a mPAP<25 mmHg (group B), and patients with a TRV≥2.5 m/s and a mPAP≥25 mmHg (group C). Survival curves were constructed using the Kaplan-Meier method and compared using the log-rank test. Cox proportional hazards modeling was used to compute hazard ratios (HR) along with their 95% confidence intervals (CI95). Results The 398 enrolled patients were followed-up for a mean time of 106±26 months (median 112 months, interquartile range 106-119). TRV was≥2.5 m/s in 109 patients (27.4%). RHC was performed in 98 of them and confirmed PH diagnosis (mPAP≥25 mmHg) in 24 (6%). Overall survival was significantly decreased in patients with a TRV≥2.5 m/s (groups B/C vs. A; HR=2.5 [CI95 1.3-4.7], p=0.006, Figure 1A). However, after accounting for mPAP level, no statistically significant difference was found between patients with a TRV<2.5 m/s and those with TRV≥2.5 m/s and mPAP<25 mmHg (group A vs. B, log-rank p=0.54), while patients with a TRV≥2.5 m/s and a confirmed diagnosis of PH by RHC (mPAP≥25 mmHg) had a significantly decreased survival in comparison with the two other groups (groups A/B vs. C, p<0.0001, Figure 1B), yielding the following HRs in Cox analysis: HR=1.0 (group A), HR=1.3 (group B, CI95 0.5-3.0, p=0.59] and HR=6.0 (group C, CI95 2.7-13.3, p<0.0001). At time of inclusion, patients with confirmed diagnosis of PH by RHC (group C) were older and characterized by lower 6-min walk distance, higher rate of leg ulcers, lower PaO2 and forced vital capacity, and higher levels of alkaline phosphatase, lactate deshydrogenase and γ-glutamyl transferase (all p<0.05). Clearance of creatinine was significantly lower in both groups with TRV≥2.5 m/s. All these parameters and systemic arterial pressures at time of inclusion were associated with a higher risk of mortality in univariate analysis. Conclusion While an isolated VRT≥2.5 m/s on transthoracic echocardiography was found to be a moderate prognostic factor for overall survival, our findings reveal highly contrasted outcomes depending on the mPAP values measured by RHC. Only the combination of a VRT≥2.5 m/s and a mPAP≥25 mmHg is associated with a worse prognosis, confirming that a RHC is mandatory in case of PH suspicion on transthoracic echocardiography in SCD patients. Disclosures Bartolucci: Addmedica: Research Funding; GBT: Membership on an entity's Board of Directors or advisory committees; Fondation Fabre: Research Funding; Novartis US: Membership on an entity's Board of Directors or advisory committees.

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