Crizanlizumab and comparators for adults with sickle cell disease: a systematic review and network meta-analysis

Real-World Data of Crizanlizumab in Sickle Cell Disease: A Single-Center Analysis

Background

Crizanlizumab was approved by the United States Food and Drug Administration agency in 2019 for decreasing vaso-occlusive events (VOEs) in sickle cell disease (SCD). Data regarding the use of crizanlizumab in the real-world setting are limited. Our goal was to identify patterns of crizanlizumab prescriptions in our SCD program and evaluate the benefits and identify barriers to its use in our SCD clinic.

Methods

We conducted a retrospective analysis of patients who received crizanlizumab at our institution between July 2020 and January 2022. We compared acute care usage patterns before and after initiation of crizanlizumab, adherence to treatment, discontinuation and reasons for discontinuation. High utilizers of hospital-based services were defined as those with more than one visit to the emergency department (ED) per month or more than three visits to the day infusion program per month.

Results

Fifteen patients received at least one dose of crizanlizumab 5 mg/kg of actual body weight during the study period. The average number of acute care visits decreased following crizanlizumab initiation but was not statistically significant (20 visits vs. 10 visits, P = 0.07). Among high users of hospital-based services, the average number of acute care visits decreased after initiation of crizanlizumab (40 vs. 16, P = 0.005). Only five patients included in this study remained on crizanlizumab 6 months after initiation.

Conclusion

Our study suggests that crizanlizumab use may be helpful in decreasing acute care visits in SCD, particularly among high utilizers of hospital-based acute care services. However, the discontinuation rate in our cohort was extremely high, and further evaluation of efficacy and causes contributing to discontinuation in larger cohorts is warranted.

Efficacy and safety of pharmacological interventions for managing sickle cell disease complications in children and adolescents: Systematic review with network meta-analysis

This study aimed to synthesize the evidence on the effects of disease-modifying agents for managing sickle cell disease (SCD) in children and adolescents by means of a systematic review with network meta-analyses, surface under the cumulative ranking curve (SUCRA) and stochastic multicriteria acceptability analyses (SMAA) (CRD42022328471). Eightteen randomized controlled trials (hydroxyurea [n = 7], l-arginine [n = 3], antiplatelets [n = 2], immunotherapy/monoclonal antibodies [n = 2], sulfates [n = 2], docosahexaenoic acid [n = 1], niprisan [n = 1]) were analyzed. SUCRA and SMAA demonstrated that hydroxyurea at higher doses (30 mg/kg/day) or at fixed doses (20 mg/kg/day) and immunotherapy/monoclonal antibodies are more effective for preventing vaso-occlusive crisis (i.e., lower probabilities of incidence of this event; 14, 25, and 30%, respectively), acute chest syndrome (probabilities ranging from 8 to 30%), and needing of transfusions (11-31%), while l-arginine (100-200 mg/kg) and placebo were more prone to these events. Therapies were overall considered safe; however, antiplatelets and sulfates may lead to more severe adverse events. Although the evidence was graded as insufficient and weak, hydroxyurea remains the standard of care for this population, especially if a maximum tolerated dose schedule is considered.

Efficacy and safety of pharmacological interventions for managing sickle cell disease in children and adolescents: protocol for a systematic review with network meta-analysis

INTRODUCTION

Sickle cell disease (SCD), an inherited haemoglobinopathy, has important impact on morbidity and mortality, especially in paediatrics. Previous systematic reviews are limited to adult patients or focused only on few therapies. We aim to synthesise the evidence on efficacy and safety of pharmacological interventions for managing SCD in children and adolescents.

METHODS AND ANALYSIS

This systematic review protocol is available at Open Science Framework (doi:10.17605/OSF.IO/CWAE9). We will follow international recommendations on conduction and report of systematic reviews and meta-analyses. Searches will be conducted in PubMed, Scopus and Web of Science (no language nor time restrictions) (first pilot searches performed in May 2022). We will include randomised controlled trials comparing the effects of disease-modifying agents in patients with SCD under 18 years old. Outcomes of interest will include: vaso-occlusive crisis, haemoglobin levels, chest syndrome, stroke, overall survival and adverse events. We will provide a narrative synthesis of the findings, and whenever possible, results will be pooled by means of pairwise or Bayesian network meta-analyses with surface under the cumulative ranking curve analyses. Different statistical methods and models will be tested. Dichotomous outcomes will be reported as OR, risk ratio or HR, while continuous data will be reported as standard mean differences, both with 95% CI/credibility interval. The methodological quality of the trials will be evaluated using the Risk of Bias 2.0 tool, and the certainty of the evidence will be assessed with the Grading of Recommendations Assessment, Development and Evaluation approach.

ETHICS AND DISSEMINATION

This study refers to a systematic review, so no ethics approval is necessary. We intent to publish our findings in international, peer-reviewed journal. Data will also be presented to peers in scientific events. Additionally, the results obtained in this study may contribute towards the update of therapeutic guidelines and for the development of health policies for SCD.

PROSPERO REGISTRATION NUMBER

CRD42022328471.

A critical evaluation of crizanlizumab for the treatment of sickle cell disease

INTRODUCTION

P-selectin is a key adhesion molecule in the pathogenesis of sickle cell disease, including acute painful event(s). Many of the mediators activated in prototypical pain crisis are also involved in other complications seen in this population. Crizanlizumab is a monoclonal antibody approved in the US in 2019 for patients of all genotypes of sickle cell disease. By blocking P-selectin, it effectively prevents acute painful event(s) and has a manageable safety profile.

AREAS COVERED

In this review, we provide an overview of the (i) biology of P-selectin in sickle cell disease, (ii) various agents inhibiting P-selectin, (iii) pharmacology of crizanlizumab, (iv) preclinical and clinical data on crizanlizumab, and (v) its potential for other indications, ongoing studies, regulatory status, and cost issues. Further, we describe its position among other approved agents in sickle cell disease and project future directions as well.

EXPERT OPINION

Crizanlizumab holds great promise in modulating the natural history of sickle cell disease and may have pleotropic effects. Studies are ongoing to define its role in preventing other sickle cell-related complications, non-sickle cell inflammatory states, and thrombotic disorders.

Flow adhesion of whole blood to P-selectin: a prognostic biomarker for vaso-occlusive crisis in sickle cell disease

Blood cell adhesion to P-selectin and vascular cell adhesion molecule-1 (VCAM-1) contributes to the pathophysiology of vaso-occlusion crisis (VOC) events in individuals with sickle cell disease (SCD). We evaluated the use of standardized flow adhesion biomarkers in a six-month, 35-subjects longitudinal study (ELIPSIS). Flow adhesion of whole blood on P-selectin (FA-WB-Psel) and VCAM1 (FA-WB-VCAM), and of isolated white blood cells on P-selectin (FA-WBC-Psel) and VCAM-1 (FA-WBC-VCAM) were elevated on VOC days compared with non-VOC days, but only FA-WB-Psel reached statistical significance (P = 0·015). Optimal cut-off values were established with Cox regression models for FA-WB-Psel [46 cells/mm²; hazard ratio (HR): 2·3; 95% confidence interval (CI):1·4-4·0; P = 0·01] and FA-WB-VCAM (408 cells/mm², HR:1·8; 95% CI: 0·9-3·45; P = 0·01). A combined (FA-WB-Psel and FA-WB-VCAM) multimarker risk score was also significantly (P = 0·0006) correlated with VOC risk that was two-fold higher for intermediate and 5·64-fold higher for high score. The concordance (C)-index for the multimarker score was 0·63 in the six-month period (95% CI: 0·56-0·70), indicating a better ability to distinguish patient risk of VOC, compared to individual biomarkers FA-WB-VCAM (C-index: 0·57; 95% CI: 0·49-0·65) or FA-WB-Psel (C-index: 0·58; 95% CI: 0·53-0·62). The presented multimarker score can be used to risk-stratify individuals with SCD during their steady state into low, intermediate, and high-risk strata for self-reported VOCs. Such risk stratification could help focus healthcare resources more efficiently to maintiain health, personalize treatment selection to each patient's individual needs, and potentially reduce healthcare costs.

Complement in Sickle Cell Disease: Are We Ready for Prime Time?

Sickle cell disease (SCD) is a widely spread inherited hemoglobinopathy that includes a group of congenital hemolytic anemias, all characterized by the predominance of sickle hemoglobin (HbS). Its features are anemia, predisposal to bacterial infections and complications such as vaso-occlusive crisis (VOC) or delayed hemolytic transfusion reaction (DHTR), which lead to increased rate of morbidity and mortality even in the era of hydroxyurea. The interaction between sickle cells, neutrophils, platelets or endothelial cells in small vessels results in hemolysis and has been considered the disease’s main pathophysiological mechanism. Complement activation has been reported in small cohorts of SCD patients, but the governing mechanism has not been fully elucidated. This will be important to predict the patient group that would benefit from complement inhibition. Until now, eculizumab-mediated complement inhibition has shown beneficial effects in DHTR, with limited reports in patients with VOC. In the meantime, several innovative agents are under clinical development Our state-of-the-art review summarizes current data on 1) complement activation in SCD both in steady state and crisis, 2) underlying mechanisms of complement over-activation for the clinician in the context of SCD, 3) actions of hydroxyurea and new therapeutic approaches including indirect involvement in complement activation, and 4) novel paradigms in complement inhibition.