Vaso-occlusive Crises In Patients Research Articles

Coexistence of Sickle Cell Thalassaemia with Overlapping Syndrome: A Case Report of Systemic Lupus Erythematosus and Autoimmune Hepatitis

This case report highlights a rare and unique occurrence: the simultaneous presence of sickle cell thalassaemia and overlapping syndrome, which involves systemic lupus erythematosus and autoimmune hepatitis. The coexistence of sickle cell disease with overlapping syndrome is exceptionally rare, with only a few documented cases in the literature, one of which involves sickle cell β-thalassaemia. Significantly, this case enhances understanding of the intricate relationship among these conditions, and offers valuable perspectives on how to clinically manage them. The authors present the case of a young male in his early 20s, who presented with haemolytic anaemia, jaundice, joint pain, and hepatomegaly. Extensive laboratory investigations, including serological markers, haemoglobin electrophoresis, and liver function tests, confirmed the coexistence of sickle cell thalassaemia, systemic lupus erythematosus, and autoimmune hepatitis. The treatment included O2 therapy, hydration, hydroxyurea, and antibiotics. After 4–5 days, the patient showed improvement, and at discharge, hydroxyurea and folic acid were continued. Significantly, considering the complex medical history of the patient, a decision was made to include a carefully considered, low-dose steroid regimen. The choice of a maintenance dose over an induction therapy was specifically made to mitigate potential complications, particularly the risk of vaso-occlusive crises in patients with sickle cell disease. This case report contributes to the understanding of concurrent manifestation of these complex conditions, and emphasises the importance of a comprehensive approach, early diagnosis, and timely management, to optimise patient outcomes in such intricate overlapping syndromes.

Spontaneous Extradural Hematoma in a Sickle Cell Anemia Patient with Hyperinflammation and Thrombotic Microangiopathy successfully treated with Eculizumab: A case report and review of the literature.

Background The event of extradural hematoma in the absence of head trauma is a rare central nervous system complication of sickle cell disease. We report here a case of spontaneous extradural hematoma in a patient being treated for sickle cell vaso-occlusive crisis complicated by hyperinflammation and thrombotic microangiopathy. The significance of inflammation as an integral component of the pathomechanism of vaso-occlusive crisis in patients with sickle cell disease and the role of heme in activating the complement system's alternative pathway are highlighted in this case report. Case Presentation A teenage patient with sickle cell disease developed a spontaneous right parietal extradural hematoma while receiving treatment for sickle cell vaso-occlusive crisis. The concurrent events of hyperinflammation, disseminated intravascular coagulation, hyperhemolysis syndrome, thrombotic microangiopathy and refractory post-operative bleeding complicated this patient's clinical course after surgical evacuation of extradural hematoma. This patient was subsequently treated with eculizumab and improved in the days following. Conclusion Treatment with the anti-C5 monoclonal antibody eculizumab which targets and inhibits terminal complement system activation reversed the deleterious cascade of events in this patient with sickle cell disease.

Abstract TMP7: Disruption of Blood Brain Barrier is Associated With Silent Cerebral Infarcts in Patients With Sickle Cell Disease

Background: Microvascular thromboinflammation is a major pathomechanism underlying vaso-occlusive crisis in patients with sickle cell disease (SCD), yet its role underlying the elevated stroke risk in SCD is unclear. Tissue-based blood brain barrier (BBB) imaging, as a metric of cerebral thromboinflammation, has not been well studied in SCD. We hypothesized that BBB permeability would be increased in patients with SCD and associated with ischemic burden. Methods: Ten young adults with SCD and 17 controls underwent dynamic contrast-enhanced and multimodal MRI to quantify BBB gadolinium leakage rates (Ktrans), white matter microstructural disruption (increased mean diffusivity, MD), and volume of silent cerebral infarcts (SCI). Infarct voxels were removed to avoid the confounding effects of measuring Ktrans in previously infarcted tissue. Whole brain mean Ktrans measures were compared between SCD vs. controls. Bivariate Spearman’s rank correlations measured relationships between Ktrans and SCI volume / MD. Results: BBB permeability, measured by whole brain Ktrans, was elevated in SCD vs. controls (Fig A). Compared to controls, Ktrans was elevated in SCD with infarcts (B), while SCD without infarcts did not differ from controls. In participants with infarcts, Ktrans, measured within non-infarcted tissue, positively correlated with SCI volume (Rho=0.6, p =0.015, C). Furthermore, whole brain Ktrans, positively correlated with MD in normal appearing white matter (Rho=0.5, p =0.01). Conclusion: Our preliminary data suggest BBB permeability is elevated and associated with stroke and microstructural injury in young adults with SCD. We are enrolling more participants. Children with SCD may also have BBB injury but will require a novel non-contrasted MR approach to assess. BBB permeability may provide new insight into the increased stroke risk in SCD. Targeting thromboinflammation and preserving BBB integrity may lead to novel neuroprotective pathways.

Real-world experience of patients with sickle cell disease treated with crizanlizumab.

In 2019, crizanlizumab was approved by the Food and Drug Administration (FDA) to reduce the rate of vaso-occlusive crisis in patients with sickle cell disease (SCD). We aimed to study the real-world effectiveness of crizanlizumab in our comprehensive sickle cell center. This was a retrospective cohort analysis of patients with SCD who received at least two consecutive doses of crizanlizumab. Clinically significant improvement was captured using the patient global impression of change scale (PGI-C). As of December 2022, there were 18 patients eligible for analysis with a median age of 30.5 years. Eight patients had the HbSS genotype, 7 HbSC, and 3 HbSB null genotype. Median duration of exposure to crizanlizumab was 53.6 weeks, and 16 (88.9%) patients received crizanlizumab for ≥26 weeks. Crizanlizumab was very well tolerated with no serious adverse events (grade ≥3) related to treatment. There was no significant difference in laboratory parameters. There was a remarkable improvement in patients' subjective response to crizanlizumab infusion. The median PGI-C score of our patients was 5, signifying moderately better with slight but noticeable changes. The morphine equivalent daily doses (MEDD) were lower after crizanlizumab infusion. MEDD prior to crizanlizumab was 90; after ≥2 consecutive crizanlizumab doses, it was 60. There was also a reduction in the hospital admissions, emergency, and urgent care visit for acute pain crisis in 6 (28%) patients. This study shows that crizanlizumab was associated with improvement in patients' response, both directly and indirectly related to the reduction of opioids used, which is consistent with results from the SUSTAIN trial.

Fucosyltransferase VII (FUT7) Activity in Patients with Sickle Cell Disease and Healthy Controls

Background:Sickle cell disease (SCD) is a severe monogenic disorder with a majority of the affected individuals living in Africa. Vaso-occlusion is a significant cause of morbidity and mortality in SCD, and selectin mediated intercellular adhesion is recognized as an important target for therapy. As such Anti-P-selectin agents are in clinical use to reduce the frequency of vaso-occlusive crises (VOCs) in SCD patients. Sialyl lewis x is a crucial ligand common to all members of the selectin family and the final step in the biosynthesis of sialyl lewis X antigen (fucosylation), is catalysed by Fucosyltransferase VII (FUT7). This enzyme is most expressed in leukocytes and endothelial cells. We hypothesized that FUT7 enzyme activity is abnormal in SCD patients and differs by VOC severity. We sought to measure plasma levels of FUT7 in SCD patients and healthy controls, and investigate their association with clinical and laboratory features, such as the frequency of VOCs. Methods:This wasa single centre cross-sectional analytical study at the University of Nigeria Teaching Hospital, Enugu. 38 steady state adult SCD patients and 40 HbAA age- and sex-matched healthy control subjects were enrolled. SCD patients were stratified by clinical severity into: Group A- 19 subjects with mild disease (0-1 crises and no disease complication such as stroke, chronic leg ulcers, nephropathy, or avascular necrosis in the previous year), and Group B- 19 patients with moderate to severe disease (2 or more crises in the previous year, with or without complications). We excluded patients with red cell transfusion within 4 months, on hydroxyurea, or other agents that may affect vaso-occlusive crisis frequency, and co-existing chronic disorders unrelated to SCD, such as asthma and diabetes mellitus. We performed a CBC and plasma FUT7 enzyme concentration measurements (ELISA kit, MyBiosource Inc, USA). Statistical analysis was performed with SPSS version 22.0 for Windows. A 2-tailed P value of <0.05 was used. Results:Our subjects were predominantly female (SCD 52.5%, HbAA 55%), with median age 28 years (range 19-46 and 19-45 for SCD and HbAA, respectively). Median frequency of VOCs in patients was 1 (range 0-5). Avascular necrosis (32.5%) was the most common complication, while stroke, acute chest syndrome, and eye disease were the least common. As expected, SCD patients had lower haemoglobin levels than HbAA (7.9±1.3g/dL vs. 12.6±1.4g/dL, P<0.001). Significantly higher WBC, ANC, and platelet counts were observed in SCD patients compared with HbAA controls (P<0.001). No significant correlations were found between FUT7 and haematocrit (r =0.06), WBC count (r = -0.08), neutrophil count (r = -0.12), and platelet count (r =0.1), with P values of 0.7, 0.6, 0.5, and 0.6, respectively. We found no difference between the median and IQR values of plasma FUT7 of SCD (2.1; 1.8-2.5) and controls (2.2; 1.8-2.8), P = 0.7. FUT7 activity was higher in SCD subjects in Group A (2.2; 1.9-2.9) than in Group B (2.0; 1.2- 2.4), with a trend towards significance P = 0.1. Discussion:In this study, FUT7 activity did not differ between SCD patients and controls. We also did not find correlations between FUT7 and blood cell counts, suggesting that plasma FUT7 activity is not increased at baseline in SCD and that the degrees of anemia or leukocytosis are not associated with changes in FUT7. Nonetheless, a mild decrease in FUT7 levels was found in more severe SCD patients and should be confirmed in a larger study. Our study did not evaluate patients in crises or who received hydroxyurea and/or other SCD-modifying therapies. Since FUT7 catalyses selectin expression, variation in its activity may be more relevant in subgroups of SCD patients on anti-selectin therapies. Future studies should be carried out in such patients to explore FUT7 activity as a marker of acute vaso-occlusion and as a modifier of response to therapy.

Inclacumab Reduce Preexisting Red Blood Cell Adhesion to Activated Endothelial Cells: In-Vitro Assessment of the Microfluidic Platform Endothelium-on-a-Chip

Background: In 2019 FDA approved the use of an antibody anti P-selectin (Crizanlizumab) for the treatment of sickle cell disease (SCD) to reduce the vaso occlusive crisis (VOCs). New anti-adhesive treatments are being developed recently. Global Blood Therapeutics, Inc., acquired by Pfizer Inc. in October 2022, acquired Inclacumab from Roche and started two clinical trials now in phase 3 to evaluate the capacity of this humanized IgG4 monoclonal antibody anti P-selectin to reduce the VOCs in patients with SCD. In our recent work presented at EHA 23 in Frankfurt Germany, we showed that Inclacumab prevents the adhesion of RBCs to chronically and acutely heme activated human umbilical vein endothelial cells (HUVECs) with a statistically significant higher effect in comparison to Crizanlizumab. In this work we used a similar approach to test the capacity of Inclacumab in the reduction of preexisting adhesion events on acutely heme activated HUVECs. Methods:Whole blood EDTA samples from six SCD subjects all with HbSS genotypes were collected at University Hospital Cleveland Medical Center, Cleveland, OH, USA. To standardize the samples, we isolated RBCs by centrifugation and subsequential washes in Phospahte buffer s of the whole blood and resuspended in basal cell culture medium (EBM; Lonza, Morristown, NJ, USA) at a hematocrit of 20% with 10 mM of HEPES. HUVECs (Lonza, Morristown, NJ, USA) were introduced and maintained within the endothelialized microfluidic channels at physiological flow for at least 48-72 hours prior to experiments. We performed an acute short-term activation, where the blood samples were supplemented with 40 µM heme +/- 100 µg/ml injected through the microfluidic channels for 15 minutes, after the adhesion took place we washed the non-adherent cells with Inclacumab and Crizanlizumab and we compared with untreated washing buffer (both compounds were provided by Global Blood Therapeutics, Inc., a wholly owned subsidiary of Pfizer Inc. South San Francisco, CA, USA) A phase-contrast images of the remaining RBCs were acquired with an inverted microscope (DMi8 Leica Microsystems Inc. Deerfield, IL, USA) and quantified based on previous published methods (Figure 1A). Paired t-test was used to calculate statistical significance. Results: Acute short-term heme activation induces high level of RBCs adhesion. Both compounds Inclacumab and Crizanlizumab showed a reduction of the number of adherent RBCs to the activated heme, but only Inclacumab results statistically a significant higher reduction compared to untreated RBCs (Figure 1B). Conclusions: Inclacumab is able not only to prevent the adhesion of RBCs to acutely and chronically activated HUVECs but is able to remove the preexisting adhesion and results in significant higher reduction compared to untreated. RBCs adhesion assay on Endothelium-on-a-chip is a novel and efficient way to study the efficacy of the new antiadhesive drug and could be used to monitor patient response to new therapies in SCD. Figure1 : Effect of Inclacumab vs Crizanlizumab on removal of SCD RBC adhesion to heme activated HUVECs. A) Schematic of adhesion experiment and inverted microscope contrast of phase images 10X of adherent RBCs at acutely heme activated HUVECs. B) Inclacumab has statistically significant effect on remove adherent RBCs to acutely heme activated HUVECs (p=0.009, N=7) For all experiments, the heme concentrations were 40 µM and Inclacumab and Crizanlizumab were 100 µg/ml. Scale bare 20 µm. P-values were based on paired t-test. Error bars represent the standard error of the mean (SEM)

Alterations of Cerebral Metabolites Are Associated with Frequency of Vasoocclusive Crises and Pain Sensitivity in Patients with Sickle Cell Disease

Purpose Sickle cell disease (SCD) is an inherited hemolytic disorder complicated by acute and chronic pain. Acute vasoocclusive crises (VOCs) associated with SCD are extremely painful episodes that are recurrent, unpredictable, and frequently require hospitalization and opioids for pain control. Changes in brain metabolites were identified in other chronic pain populations but haven't been well studied in SCD. Our ongoing trial (ClinicalTrials.gov Identifier: NCT05045820) aims to evaluate the characteristics of brain metabolites in SCD and understand the relationship between the altered cerebral metabolite(s) and clinical pain in patients with SCD. Materials and Methods Metabolite measurements from a single voxel (size: 2×3×3 cm 3) located within the posterior insula cortex (PIC) were acquired from 26 patients with SCD (31.9 ± 13.9 years, 14-73; 14 females) and 19 healthy controls (HCs) (37.9 ± 16.4 years, 17-62; 10 females) with PRESS (TR/TE = 3000/25 ms, Averages =128) and MEGA-PRESS (TR/TE = 3000/68 ms, Averages =256) sequences using a Siemens Prisma 3T scanner. Written consent was obtained from each participant before scanning. LCModel was used for PRESS analysis to obtain concentration values of glutamine + glutamate (Glx), total creatine (tCr), N-acetylaspartate (NAA), total choline (tCho), and myoinositol (MI). Gannet was used for processing MEGA-PRESS data to estimate GABA+. Ratios of each metabolite to tCr were also quantified. Tissue correction for cerebrospinal fluid was performed for each voxel using the tissue composition estimated from SPM12. The Cramer-Rao Lower Bounds of each metabolite analyzed with LCModel was less than 20%. The frequency of VOCs in the preceding 12 months was recorded for each participant. A moderate pressure pain stimuli (using a 0-100 scale with “0” representing “no pain” and “100” representing “most intense pain imaginable”, pain rating at 40-60 abbreviated as P40 is considered as moderate pain) was delivered via a pressure cuff to the gastrocnemius area of the non-dominant leg using a validated MR-compatible air compressor to induce a tonic pressure pain for 8 min right before MRS scan. Higher pressure intensity (mmHg) of P40 indicated higher pain tolerance and lower pain sensitivity. Correlation between the brain metabolites and pain-related outcomes was studied. Results Due to the large range of age in the SCD group, the brain metabolite profile was compared between 17 SCD patients and 17 ethnicity-, age- and gender-matched HCs. The concentration of Glx (p =0.012) and ratio of Glx to tCr (p =0.034) in PIC were significantly higher in patients with SCD compared to HCs (Figure 1). Within the SCD patient group, there was a significant positive correlation between frequency of VOCs in the preceding 12 months and Glx/tCr (r= 0.39, p=0.047, Spearman's), a significant negative correlation between P40 and Glx (r= -0.46, p=0.019, Spearman's). There were no group differences in any other metabolites. Conclusion We find increased Glx in the PIC in patients with SCD. Previous studies have also found increased Glx and/ or Glx/tCr in the PIC as well as other brain regions including the amygdala, the posterior cingulate, the ventral lateral prefrontal cortex and the anterior insula in fibromyolgia. The PIC is thought to be involved in discriminative activities of sensory pain, which suggests that Glx in PIC is related to pain processing in patients with SCD. Glx/tCr was correlated with frequency of VOCs in patients with SCD, indicating that the SCD patients with higher level of Glx/tCr had more VOCs in the preceding 12 months. In addition, the SCD patients with higher level of Glx had lower pressure intensity of P40, suggesting that elevated Glx in the PIC was related to higher pain sensitivity. Our preliminary data provide the first evidence of a link between alterations in excitatory neurotransmitter levels in the PIC in patients with SCD and indicates new information of potential brain markers for pain in SCD, which may guide treatment. Clinical Relevance Statement: Treatment of pain in SCD remains very challenging in part due to a lack of understanding of the underlying mechanisms and pathophysiology of pain. Brain excitatory neurotransmitters and their relationship with pain have been largely unexplored in SCD. These findings indicate that the relationship between clinical outcomes and excitatory brain neurotransmitters may be a potential objective outcome measure in SCD.

Identifying Inflammatory and Immune Markers Associated with Vasoocclusive Crisis in Patients with Sickle Cell Disease

Background: Sickle cell disease (SCD) is an inherited disorder that can cause a range of clinical complications, featured by unpredictable and recurrent acute painful episodes associated with vasoocclusive crises (VOCs). Individuals with SCD experience frequent VOCs and require high doses of opioids for pain control. Thus far, studies on biomarkers associated with VOCs in SCD are very limited and the known markers are hardly considered as critical end points in studying VOCs in SCD. This study aimed to comprehensively analyze immune and inflammatory characteristics of patients with SCD to understand the disease-specific pathogenesis and develop targeted diagnostic and therapeutic strategies related to VOCs. Methods: The study cohort consisted of 40 patients with SCD aged 14-73 years (23 female, 58%), recruited for an ongoing clinical trial (ClinicalTrials.gov Identifier: NCT05045820). Twenty-three ethnicity-, age- and gender-matched pain-free participants were also enrolled as healthy controls (HCs) (Table 1). Multiplex immunoassays were used to profile 80 inflammatory cytokines/chemokines/growth factors and 18 autoantibodies in plasma samples from patients with SCD and the matched HCs. Peripheral blood mononuclear cells were used to profile immune cells. Statistical analysis was performed using GraphPad Prism with Mann-Whitney test, χ 2 test, and Spearman's correlation. P < 0.05 was considered statistically significant. Results: Patients with SCD exhibited significantly higher plasma levels of 34 analytes, including 12 pro-inflammatory/anti-inflammatory cytokines (IFN-γ, IL-1α, IL-2, IL-8, IL-9, IL-18, TNF-α, TNF-β, IL-4, IL-5, IL-6, and TSLP), 10 chemokines (CCL21, CCL23, Eotaxin-2, Gal-3, GRO-α, IP-10, MCP-2, MIP-1α, MIP-1β, and MIP-3α), 8 growth factors (bNGF, G-CSF, GM-CSF, HGF, IL-7, IL-20, IL-34, and LIF), 2 effectors (granzymes A and B), and 2 soluble receptors (PTX3, TREM-1). Higher activation levels of B cells, CD4 T cells, CD8 T cells, and MAIT cells were seen in patients with SCD. Autoantibody profiles were also altered in patients with SCD, with elevated levels of antibodies against SSA/Ro60, Ribosomal P, Myeloperoxidase, and PM/Scl-100. Levels of cytokines/chemokines/growth factors were correlated with time interval between blood draw and occurrence of VOCs. Four soluble factors (Eotaxin-2, GRO-α, IL-6, and LIF) were positively associated with time interval after VOCs, while two factors (IL-18 and granzyme A) showed negative associations with time interval, suggesting that the altered inflammatory mediators were associated with the occurrence of VOC events. Conclusion: Our results provide novel and comprehensive understanding of the immune and inflammatory dysregulation in patients with SCD and their relationship with occurrence of VOCs, offering insights into potential SCD-specific biomarkers for further investigation.

Omega-3 Fatty Acid Supplements in Reducing Vaso-Occlusive Crisis Hospitalizations in Patients with Sickle Cell Disease: A Systemic Review and Meta-Analysis

Introduction Omega-3 fatty acids (O3FA) have been evaluated in various clinical settings for sickle cell disease (SCD) patients with promising results. This study aims to assess the efficacy and safety of O3FA supplements in preventing SCD complications. Methods We systematically searched Embase, PubMed, and Cochrane Register of Controlled Trials from inception to May 26 th, 2023. Studies that met the following criteria were included: (1) randomized controlled trials (RCTs) or nonrandomized studies of interventions; (2) comparing O3FA supplements to the standard of care (with or without hydroxyurea treatment); (3) patients with sickle cell disease; (4) and reporting at least one clinical outcomes of interest. We excluded studies (1) with unstable treatment history 3-6 months before the beginning of the studies; or (2) with patients on regular blood transfusion. Our outcomes of interest included (1) the frequency of painful vaso-occlusive crisis or acute chest syndrome requiring hospitalization; and (2) hemoglobin level after intervention. We used Review manager software to perform statistical analyses. The random effect model was applied to all analyses due to anticipated heterogeneity. Pooled mean differences and 95% confidence intervals (CI) were used to assess outcomes. Results We screened 188 studies and included four RCTs and one self-controlled cohort in the meta-analysis. Our population included 349 patients aged between 2 years to adults; 54.7% received O3FA supplements. The docosahexaenoic acid (DHA) dose ranged from 10 to 60 mg per kilogram daily. Follow-up varied from 3 to 12 months. More than two-thirds were hemoglobin SS disease, as presented in Table 1. Other SCD syndromes included hemoglobin S-beta 0 thalassemia and hemoglobin SC disease. Severe baseline disease (³ 3 episodes of painful vaso-occlusive crisis per year requiring hospital admission) ranged between 23.5% and all patients among studies. The vaso-occlusive crisis episodes were significantly reduced in the O3FA group compared with standard treatment: mean difference (MD)-1.63 times (95% CI: -2.35 to -0.91; p = 0.00001; I 2 = 54%), as seen in Figure 1a. There was no difference in hemoglobin levels after intervention with O3FA versus standard treatment (MD: 0.03; 95% CI: -0.25 to 0.32; p = 0.82). In the subgroup of patients without hydroxyurea treatment, the mean frequency of vaso-occlusive crisis was significantly lower with O3FA supplements compared with standard treatment (MD: -1.60; 95% CI: -2.47 to -0.72; p = 0.0004; I 2 = 67%), as shown in Figure 1b. There were no significant adverse events (AE) in the O3FA group. The most common AE were increased appetite, dyspepsia, and occasional “fishy” smell. One patient discontinued O3FA supplements because of drug-related abdominal pain. Conclusion Our systematic review and meta-analysis support O3FA supplementation as a safe and effective complementary strategy to reduce painful vaso-occlusive crises in patients with SCD.

Primary Analysis of Spartan: A Phase 2 Trial to Assess the Efficacy and Safety of Crizanlizumab in Patients with Sickle Cell Disease Related Priapism

Introduction: Priapism is a painful, sustained penile erection that occurs in 35% of adult men with sickle cell disease (SCD) and may result from the underlying mechanism of vaso-occlusion. To date, there is no effective disease-modifying drug proven to treat priapism. Crizanlizumab is a monoclonal antibody that binds and blocks P-selectin, a key mechanistic component of vascular endothelial adhesion. Based on the results of the SUSTAIN trial, crizanlizumab was approved by the FDA to reduce the frequency of vaso-occlusive crises in patients with SCD aged ≥16 years. In this primary analysis of the Phase 2 SPARTAN trial (NCT03938454), we evaluated the efficacy and safety of crizanlizumab after 26 weeks of treatment in patients with SCD-related priapism. Methods: The SPARTAN trial included male patients aged ≥12 years with all SCD genotypes who experienced ≥4 priapic episodes lasting ≥60 min over the 14-week period preceding screening. Eligible patients also experienced ≥3 priapic episodes during the subsequent 12-week screening period with ≥1 event occurring within 4 weeks prior to the first treatment. After enrollment priapic events were documented through electronic self-reporting tools and validated patient-reported outcomes surveys for 26 weeks and included start/end date, sleep status, duration, non-pharmacological treatment, triggers, emergency department visit, and pain intensity during the screening period. Baseline priapic events were collected for each patient during the 12-week screening period. Patients received crizanlizumab 5.0 mg/kg IV infusion on week 1, week 3, and every 4 weeks thereafter. The primary endpoint was percent reduction from adjusted baseline period in priapic events by 26 weeks. Percent reduction from baseline in priapic events was tested using a one-sided Wilcoxon's Sign Rank test. Hodges-Lehmann estimate of median percent reduction in priapic events (with 95% CIs) was also reported. Results: Data cutoff was March 28, 2023. Of the 36 patients enrolled, 26 (72.2%) were between 18 and 40 years, and the median (range) age was 29 (14-58) years. Most patients were HbSS genotype (n=29, [80.6%]) and more than half were on hydroxyurea (n=21, [58.3%]). Patient-reported history prior to crizanlizumab treatment revealed that more than half of patients experienced priapism daily or every other day (n=21, [58.3%]) and most reported a duration of 1 to 5 h (n=33, [91.7%]). The most common patient-reported emotions at the start of the study were frustration and exhaustion, reported by ≈50% of patients. The median (IQR) baseline number of priapic events adjusted for 26 weeks per patient was 42 (13-73) events ( Table). All patients experienced events lasting 1 to ≤4 h, although some also experienced severe events lasting >4 to 6 h (n=19, [52.8%]) and >6 to ≤12 h (n=11, [30.6%]). In one case, 38 days of screening period baseline data was not reported, resulting in a strong outlier that affected the results ( Patient 1, Figure). Thirty-six patients received ≥1 dose of crizanlizumab, with a median cumulative dose of 35.0 mg/kg over 26 weeks; 5 patients each missed 1 infusion and 1 patient missed 2 infusions. The Hodges-Lehmann estimate of median percent reduction from baseline in priapic events per patient was 46.0% (95% CI: 23.5%-65.4%; P=.068). Twenty-eight patients (77.8%) reported a reduction from baseline in priapic events ( Figure). A subgroup analysis revealed a trend towards a larger percent reduction in events for patients with ≥22 baseline events, possibly indicating that patients with severe disease benefitted more from treatment. The most frequent treatment-emergent adverse event (TEAE) was headache (16.7%). No patients discontinued crizanlizumab prematurely and only one patient withdrew consent by week 26. Conclusions: Primary analyses from the SPARTAN trial showed that patients with SCD-related priapism treated with crizanlizumab over 26 weeks experienced approximately half as many priapic events compared with baseline. There was a trend towards a more significant reduction in frequency of episodes in patients with severe disease. Crizanlizumab was safe and well tolerated, with observed TEAEs consistent with the safety profile seen in other clinical trials. Final analyses of the SPARTAN trial will provide data over 52 weeks and may provide further support for the role of crizanlizumab in reducing frequency of priapic events.

A multimodal pain protocol for treatment of vaso-occlusive crisis in patients with sickle cell disease: Implementation and evaluation.

Pain management during a vaso-occlusive crisis (VOC) for patients with sickle cell disease (SCD) remains a major challenge and strongly depends on opioids. We developed a multimodality pain protocol for rapid, opioid-sparing pain treatment of VOC and evaluated its feasibility. Patients were included for evaluation if they were ≥18 years, diagnosed with SCD and visited the emergency department (ED) because of VOC between July 2018 and December 2020. Primary evaluation outcome was the feasibility of multimodal pain analgesia (i.e., the use of at least two analgesics with different underlying mechanisms of action). A total of 131 SCD patients visited the ED because of VOC with a total of 550 ED presentations, of which 377 were eventually hospitalised. A total of 508 (92.4%) ED presentations and 374 (99.2%) hospital admissions received multimodal pain treatment. Time to first administration of an opioid was median [IQR] 34.0 [21.0-62.0] minutes. The implementation of a pain protocol using multimodal analgesia for VOC in patients with SCD appeared to be feasible and facilitated rapid administration of opioids. Controlled trials are needed to investigate the effectiveness of multimodal analgesia on pain and should focus on patient reported outcome measures.

Non-traumatic Cerebral Fat Emboli Syndrome in a patient with Sickle Cell Crisis (P2-5.006)

<h3>Objective:</h3> To report a patient with Sickle Cell Disease who developed Cerebral Fat Embolism Syndrome. <h3>Background:</h3> A review of literature showed that cerebral fat embolism syndrome (CFES) can occur as a symptom of bone necrosis and vaso-occlusive crisis in patients with sickle cell disease (SCD), especially in those with heterozygous variants. <h3>Design/Methods:</h3> Case report and literature review <h3>Results:</h3> We present a 67-year-old female with a PMH of Sickle cell (HbSC) disease with retinopathy, splenectomy, cholecystectomy, atrial fibrillation on Eliquis, and hypertension who was initially admitted for management of vaso-occlusive crisis and presumed avascular necrosis of the right hip. Stroke code called for deteriorating mental status. CT Head and CTA of the Head &amp; Neck were unremarkable but hyper-acute MRI of the brain was performed which showed multiple scattered embolic infarcts in both cerebral and cerebellar hemispheres. Patient was later intubated and monitored on LTM which did not show any signs of seizures or ictal-interictal abnormalities. Patient underwent erythocytopheresis with exchange of 8 Units. Pre and Post-HbS were 54% and 7% respectively. Given lack of improvement in exam, MRI Brain was repeated which showed additional foci of diffusion restriction as well as dispersed micro-hemorrhages concerning for CFES. Patient additionally underwent two sessions of plasmapheresis. <h3>Conclusions:</h3> This case illustrates that CFES should be suspected in patients with SCD when there is a change in mental status or neurologic deficit which is likely from bone marrow necrosis leading to fat globules being released into the systemic circulation. Early MRI is useful in establishing a diagnosis for prompt, timely treatment. <b>Disclosure:</b> Dr. Ebrahimi has nothing to disclose. Dr. Balabhadra has nothing to disclose. Dr. Mittal has nothing to disclose.

Emerging Therapies for the Management of Pain and Vaso-Occlusive Crises in Patients With Sickle Cell Disease: A Systematic Review of Randomized Controlled Trials.

Sickle cell disease (SCD) is an inherited disorder that impairs red blood cells (RBCs) and disrupts the delivery of oxygen to tissues. There is currently no cure. Symptoms can appear as early as six months of age and include anemia, acute episodes of pain, swelling, infections, delayed growth, and vision problems. A growing number of therapies are being investigated for reducing these episodes of pain, also known as vaso-occlusive crises (VOCs). The research literature evidence, however, currently includes far more approaches that have not shown superiority versus placebo than ones that have been proven effective. The purpose of this systematic review is to evaluate the body of randomized controlled trials (RCTs) to determine the quality of support for and against the use of a variety of current and emerging therapies for treading SCD VOCs. Several important new papers have emerged since previous systematic reviews with similar objectives were published. This review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and focused on PubMed exclusively. Only RCTs were sought, and no other filters, except for a five-year historical timeline cut-off, were used. Of the 46 publications that were returned in response to the query, 18 were ultimately accepted as meeting the pre-established inclusion criteria. The Cochrane risk-of-bias tool was utilized as a quality assessment measure, and the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) framework was used to assess the certainty of the evidence. Among the included publications, five out of 18 featured positive results with superiority and statistical significance versus placebo for either reduction in pain score or number/duration of VOCs. The approaches featured therapies ranging from de novo molecules to currently available drugs approved for other indications to naturally occurring metabolites such as amino acids and vitamins. A single therapy, arginine, was supported for both clinical endpoints: pain score reduction and shortened VOC duration. Currently, two therapies are approved by the United States Food and Drug Administration (FDA) and are commercially available (crizanlizumab, ADAKVEO and L-glutamine, Endari). All other therapies are investigational only in nature. Several studies included measurement of biomarker endpoints as well as clinical outcomes. Generally, beneficial outcomes related to improving biomarker levels did not also translate into statistically significant reduction of pain scores or number/duration of VOCs. While measuring biomarkers may contribute to the understanding of pathophysiology, it does not appear to directly offer predictive value toward treatment success clinically. It can be concluded that there exists a specific opportunity to design, fund, and execute investigations that both compare emerging and existing therapies versus one another and compare combinational therapies versus placebo.

Successful Treatment of SCD-Related Priapism With Crizanlizumab: A Case Series.

Priapism, an unwanted, painful, prolonged erection that is unrelated to sexual stimulation, is a common complication of sickle cell disease (SCD). Priapic events in SCD are stuttering, meaning they occur repeatedly with intervening periods of detumescence. Without health care intervention, repeated episodes can lead to erectile dysfunction. There are limited treatment options for SCD-related priapism and no approved targeted therapies. Crizanlizumab is a monoclonal antibody that binds to P-selectin and is used to reduce the frequency of vaso-occlusive crises in patients with SCD. Here, we report the cases of 3 patients with SCD-related priapism who were treated with crizanlizumab. All patients were African American men who experienced numerous priapic episodes that interfered with their daily lives. Upon treatment with crizanlizumab, priapic events were reduced in all 3 patients. These successful cases suggest a potential role for crizanlizumab in the prevention of SCD-related priapism.

Insights into Vaso-Occlusive Crises-Related Readmissions in Patients with SCD across Geographic Regions

Background: Sickle cell disease (SCD) is an inherited red blood cell disorder characterized by chronic anemia and hemolysis, inflammation, and vaso-occlusion that manifests clinically as recurrent, painful vaso-occlusive crises (VOCs) and widespread organ damage. VOCs are the main reason for admission to a healthcare facility (eg, hospital, emergency department [ED], observation unit, or day care). Frequent admission for VOCs is an indicator of severe disease and is associated with early mortality. In the United States, 33% of patients admitted to a healthcare facility for VOCs are readmitted within 30 days, and approximately 50% of patients are readmitted within 90 days. These high readmission rates place an enormous burden on patients, caregivers, and the healthcare system. US readmission rates may not represent 90-day readmission rates among individuals with SCD outside of the United States due to variability in healthcare settings, practices, access, and other potentially confounding factors. Objective: To explore regional differences in 90-day readmission rates for VOCs, this retrospective chart review was conducted in a sample of patients with SCD at selected sites across geographic regions. Methods: Medical records from patients with SCD (all genotypes), aged ≥12 years, who were admitted to the ED or hospital for management of a VOC during a 2-year period were evaluated for this retrospective chart review. The evaluation took place at 8 sites on 5 continents (North America, Africa, Asia, Europe, and South America). Eligible patients had a history of painful VOC episodes, including complicated VOCs of acute chest syndrome, hepatic sequestration, splenic sequestration, and priapism, requiring admission to a medical facility (hospital, ED, observation unit, or day care) for treatment. For each patient, dates of admission for a VOC requiring treatment with parenteral (intravenous or intramuscular) pain medications (eg, nonsteroidal anti-inflammatory drugs, narcotics) in the selected time were collected. Patients with SCD who had 2 to 10 VOCs within year 1 were eligible for inclusion in the chart analysis. The first admission for VOC during the second year of the study was designated as the index VOC. A subsequent VOC occurring within 90 days of the index VOC was used to determine the 90-day readmission rate. Results: The study included a review of 500 patient charts across 8 geographic regions in 6 countries: Brazil, Egypt, Italy, Lebanon, Nigeria, and the United States (Figure 1). Out of the 500 patient charts reviewed, 290 (58%) were eligible for this study. Of the eligible patients with SCD who were admitted for a VOC, those who were readmitted within 90 days were included for analysis. The proportion of patients readmitted for a VOC within 90 days ranged from 30% to 51% (Figure 2). Conclusions: Recurrent and prolonged VOC-related hospitalizations substantially disrupt the daily lives and emotional well-being of patients with SCD and are associated with increased risk of mortality. VOCs also remain the main cause for inpatient admissions, and there is an urgent need to reduce the burden of VOC-related hospitalizations. This study provides insights into 90-day readmission rates for VOCs in patients with SCD across different geographic regions. Rates of readmission due to VOCs were generally similar across the sites and consistent with rates observed in the United States. The 90-day readmission rates observed in this study suggest that similar factors may influence VOC hospitalization rates. Identification of these factors is critical for formulating interventions to reduce readmissions and the associated social and economic burden, and for facilitating efficient allocation of resources. Future analyses will include the assessment of site and practice-specific factors contributing to these results to inform physicians treating patients with SCD on potential ways to alleviate this burden on patients, caregivers, and the medical community. Funding: Global Blood Therapeutics. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Effects of Pyruvate Kinase Activators on Red Blood Cell Rheology, Sickling and Senescence in Sickle Cell Disease

Introduction: Pyruvate Kinase Activators (PKA) are a new class of pharmacological agents that enhance pyruvate kinase (PKR) activity and glycolytic flux in red blood cells (RBC), resulting in increased intracellular adenosine triphosphate (ATP) and decreased 2,3-diphosphoglycerate (2,3-DPG) contents. In patients with sickle cell disease (SCD), decreased PKR activity and thermostability result in decreased ATP/2,3-DPG ratio, which promotes HbS polymerization and sickling. Previous ex-vivo studies have shown that AG-348 (mitapivat) could represent a therapeutic option for those patients by restoring PK activity and thermostability and by increasing RBC deformability and the ATP/2,3-DPG ratio, thus reducing the propensity of RBC to sickle under deoxygenation (1). Recently, a new PKA molecule has been developed (AG-946) but its effects on RBC deformability and sickling have not been fully studied (2). Moreover, the effects of the two molecules in a context of enhanced oxidative stress - a situation frequently encountered in SCD - have not been investigated. Materials and Methods: Blood samples from non-transfused adults and children with SCD (3 to 53 years-old) were collected in EDTA tubes. HbF levels ranged from 1.3 to 47.1%. Washed RBC were resuspended in phosphate buffer saline after buffy-coat removal and incubated for 4 hours at 37°C, with or without 0.4 mM of cumene hydroperoxide (CH), a molecule that causes a considerable oxidative stress to the cells. Three different incubation conditions (AG-348 at 50 µM, AG-946 at 5 µM and a vehicle control) were systematically compared for the following ex-vivo experiments on RBC: (i) determination of the partial pressure of oxygen at which the hemoglobin is 50% saturated with oxygen (p50) with the Hemox® device; (ii) RBC deformability at normoxia (EImax and SS1/2 parameters), in hypoxia (EImin) and the partial pressure of oxygen at which sickling starts during deoxygenation (PoS; Point of Sickling) by ektacytometry; (iii) analyses of RBC senescence markers (i.e. Phosphatidylserine externalization, reactive oxygen species, intra-cellular calcium (Ca2+) and membrane CD47) by flow cytometry. One-way ANOVA with the Newman-Keuls method was performed for multiple comparisons and the significant level was set at 0.05. Results: A significant decrease of the p50 and PoS values was observed for both AG-molecules, with and without CH, compared to the control condition (Fig. 1-A). Without CH, both AG-molecules decreased SS1/2 (i.e., the shear stress for half-maximal deformation of RBCs) and AG-946 increased EImin and EImax. With CH, the two molecules still decreased the PoS compared to the control condition and a trend through an increase of EImin was observed with the AG-946 molecule. A slight increase of intra-cellular Ca2+ with the two AG-molecules (trend for AG-946) was observed in absence of oxidative stress (Fig. 2). The other RBC senescence markers were not modified, regardless of the incubation condition. Conclusion: Our results show that both PKAs increase the oxygen affinity and reduce the sickling propensity of RBCs from patients with SCD in vitro, in the presence or absence of enhanced oxidative stress. The observed small increase of intracellular Ca2+ upon drug treatment may be a result of increased overall cellular metabolic activity, as a consequence of PKR activation. Interestingly, the increased intracellular Ca2+ is not accompanied by enhanced RBC senescence. Overall, these data support testing PKA in prospective clinical trials for the reduction of vaso-occlusive crisis in patients with SCD. Bibliography: (1): Decreased activity and stability of pyruvate kinase in sickle cell disease: a novel target for mitapivat therapy. Rab MAE, Bos J, van Oirschot BA, van Straaten S, Kosinski PA, Chubukov V, Kim H, Mangus H, Schutgens REG, Pasterkamp G, Dang L, Kung C, van Beers EJ, van Wijk R.Blood. 2021 PMID: 33690814. (2): 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. Rab, MAE, Van Dijk MJ, Van Oirschot BA, Gerrits J Kosinski PA, Kung C, Jans JJM, Van Beers EJ, Dang L and Van Wijk R. 2021 American Society of Hematology Congress, Abstract 113. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

A Phase 2a, Randomized, Open-Label Study to Evaluate Multiple Dosing Regimens of Subcutaneous ALXN1820 in Adult Patients with Sickle Cell Disease

Background:Sickle cell disease (SCD) is a group of inherited disorders that result in chronic hemolysis/anemia and vaso-occlusive crises (VOC). Current management options for SCD do not adequately address both anemia and VOC. Hematopoietic stem cell transplant is the only curative treatment but is associated with life-threatening complications. Complement activation may play an important role in the pathophysiology of SCD since intravascular hemolysis of sickle red blood cells (RBCs) leads to release of free hemoglobin triggering activation of the complement alternative pathway (CAP). Intravascular hemolysis and CAP activation promotes anemia and VOC in patients with SCD. Properdin is an endogenous activator of the CAP (Roumenina LT, et al. Am J Hematol. 2020;95(5):456-464; Vercellotti GM, et al. Am J Hematol. 2019;94(3):327-33). ALXN1820 is a novel, humanized, bispecific, VHH antibody that simultaneously binds human albumin and properdin. The antibody effectively and selectively inhibits CAP activation while binding to albumin, which confers an extended circulatory half-life to the molecule. Pretreatment with a mouse anti-properdin antibody significantly ameliorated signs of hemolysis and VOC in a mouse model of SCD. The safety, pharmacokinetics and pharmacodynamics of ALXN1820 are being evaluated in an ongoing study in healthy volunteers (NCT04631562). Study design, methods, and study population: This open-label Phase 2a study will evaluate the safety, tolerability, efficacy, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of multiple doses and dosing regimens of ALXN1820 administered subcutaneously to patients with SCD (see Figure for study schema). Key inclusion criteria are confirmed diagnosis of SCD (HbSS and HbSß0-thalassemia), hemoglobin levels 5.5-10g/dL at screening, 1-10 VOC episodes in the past 12 months, and vaccination requirements (meningococcal, Haemophilus influenzae type B (Hib) and Streptococcus pneumoniae). Concomitant treatment with stable dose of hydroxyurea is permitted during the study as applicable. Key exclusion criteria are receiving voxelotor or crizanlizumab within 60 days of providing informed consent and, prior treatment with complement inhibitors within 6 months of first study dose. Key endpoints of the study are shown in the Table. Safety analyses will be performed on the Safety Population and will be reported by each cohort and treatment arm. Efficacy analyses will include absolute and percentage change from baseline to the end of the Treatment Period (12 weeks) in complement biomarkers, hemoglobin, hemolysis markers, and hemopexin for Cohort 1 and Cohort 2. Conclusion: Complement activation may play an important role in the pathophysiology of SCD. Treatment with an anti-properdin antibody significantly ameliorated signs of hemolysis and VOC in a mouse model of SCD supporting the potential of ALXN1820 to treat SCD. Data from this Phase 2 study are anticipated to confirm the potential of ALXN1820 to treat SCD and guide the design of future studies in patients with SCD and other complement-mediated diseases. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Real-World Experience of Patients with Sickle Cell Disease Treated with Crizanlizumab: A Single Comprehensive Sickle Cell Center Retrospective Cohort Analysis

Background:Sickle cell disease (SCD) is an inheritable hemoglobinopathy with great impact on patients’ quality of life and healthcare costs. In 2019, crizanlizumab, the first-in-class monoclonal antibody that target the cell adhesion molecule P-selectin, was approved by the FDA to reduce the rate of vaso-occlusive crisis in patients with SCD ≥16 years old, based on the results of the SUSTAIN trial [1]. Aim: To study the real-world effectiveness of crizanlizumab in patients with SCD ≥16 years old treated with crizanlizumab 5.0 mg/kg, with or without hydroxyurea, from 2019 to 2022 in our comprehensive sickle cell center. Methods: This is a retrospective cohort analysis of patients with SCD (all genotyped, ≥16 years old) who received at least 2 consecutive doses of crizanlizumab. Demographics and laboratory findings before and after crizanlizumab were collected and analyzed. Only data available from patients’ electronic medical records (and other secondary data sources) 1 year before (pre-index data) and after (post-index data) the ≥2 consecutive crizanlizumab doses were analyzed. Objective clinical improvement was captured using the Patients’ Global Impression of Change (PGIC) score. Descriptive statistics are presented in percentages, medians, and interquartile ranges. An independent group unpaired Student's t-test was used to determine, where appropriate, the level of significant differences among normal distribution continuous variable with p value <0.05 considered statistically significant. Data was analyzed using GraphPad Prism version 9.0.2. Results:As of July 2022, there were 18 patients eligible for analysis. The median age of patients was 30.5 (range, 19-47) years, 7 (38%) males and 11 (61%) females (Table 1). Eight patients had the HbSS genotype, 7 HbSC, and 3 HbSB null. The median duration of exposure to crizanlizumab was 53.6 weeks, and 16 (89%) patients received crizanlizumab for ≥26 weeks. Crizanlizumab is very well tolerated with no serious adverse events (grade ≥3) related to treatment reported. The most commonly reported adverse events were fatigue (n=3), followed by headache (n=2) and nausea (n=2). There was no significant difference in laboratory parameters (hemoglobin, hematocrit, total bilirubin, creatinine, or protein/creatinine ratio) between pre-index and post-index values (Table 2). Although there was improvement in reticulocytes (6.5% vs. 5.1%) and LDH (336.5 vs. 279 U/L) compared with baseline, this was not statistically significant, likely due to the small sample size (p=0.71 and p=0.98, respectively). There was a remarkable improvement in patients’ subjective response with crizanlizumab infusion. The median PGIC score of our patients was 5, signifying moderately better with noticeable changes, although slight. Twelve (67%) patients provided a score of ≥4, which signifies feeling better with changes. Conclusions: This is one of the first retrospective studies to use PGIC to capture the effectiveness of crizanlizumab in patients with SCD. This study shows that crizanlizumab was associated with an improvement in patient response that was directly and indirectly related to the reduction of vaso-occlusive crisis, consistent with findings from the SUSTAIN trial. Further large-scale studies are needed to corroborate these findings.

Monocyte HLA-DR Expression to Monitor Immune Response and Potential Infection Risks Following Vaso-Occlusive Crises in Patients with Sickle Cell Anemia.

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HSD63 Real-World Crizanlizumab Treatment Patterns of Patients with Sickle Cell Disease

Sickle cell disease (SCD) is an inherited blood disorder characterized by vaso-occlusive crises (VOCs). Crizanlizumab infusion was FDA approved in 2019 to reduce VOCs in patients with SCD ≥16 years old. There is little real-world evidence (RWE) regarding crizanlizumab use.