Natural history of paroxysmal nocturnal hemoglobinuria

Phase 3 randomized COMMODORE 2 trial: Crovalimab versus eculizumab in patients with paroxysmal nocturnal hemoglobinuria naive to complement inhibition

Crovalimab is a novel C5 complement inhibitor that enables rapid and sustained C5 inhibition with subcutaneous, low-volume self-administration every 4 weeks. COMMODORE 2 (NCT04434092) is a global, randomized, open-label, multicenter, phase 3 trial evaluating the non-inferiority of crovalimab versus eculizumab in patients with paroxysmal nocturnal hemoglobinuria not previously treated with C5 inhibition. C5 inhibitor-naive patients with lactate dehydrogenase (LDH) ≥2 × upper limit of normal (ULN) were randomized 2:1 to crovalimab or eculizumab. Co-primary efficacy endpoints were proportion of patients with hemolysis control (centrally assessed LDH ≤1.5 × ULN) and proportion with transfusion avoidance. Secondary efficacy endpoints were proportions of patients with breakthrough hemolysis, stabilized hemoglobin, and change in FACIT-Fatigue score. The primary treatment period was 24 weeks. Two hundred and four patients were randomized (135 crovalimab; 69 eculizumab). Crovalimab was non-inferior to eculizumab in the co-primary endpoints of hemolysis control (79.3% vs. 79.0%; odds ratio, 1.0 [95% CI, 0.6, 1.8]) and transfusion avoidance (65.7% vs. 68.1%; weighted difference, -2.8 [-15.7, 11.1]), and in the secondary efficacy endpoints of breakthrough hemolysis (10.4% vs. 14.5%; weighted difference, -3.9 [-14.8, 5.3]) and hemoglobin stabilization (63.4% vs. 60.9%; weighted difference, 2.2 [-11.4, 16.3]). A clinically meaningful improvement in FACIT-Fatigue score occurred in both arms. Complete terminal complement activity inhibition was generally maintained with crovalimab. The safety profiles of crovalimab and eculizumab were similar with no meningococcal infections. Most patients who switched from eculizumab to crovalimab after the primary treatment period preferred crovalimab. These data demonstrate the positive benefit-risk profile of crovalimab.

Health-related quality of life and influencing factors of patients with paroxysmal nocturnal hemoglobinuria in China

BACKGROUND

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare blood disorder, leading to various complications and impairments in patients' health-related quality of life (HRQOL). Limited research has been conducted to evaluate the HRQOL of Chinese patients with PNH. Understanding the HRQOL in this specific population is crucial for providing effective healthcare interventions and improving patient' health outcomes. This study aimed to assess HRQOL of Chinese patients with PNH, and identify key determinants.

METHODS

A cross-sectional study was conducted during 2022 to recruit patients with PNH in China. The study population was recruited from PNH China, one of the largest public welfare PNH patient mutual aid organization in China. Data were collected via an online questionnaire including the EQ-5D-5L (5L), and social-demographic and clinical characteristics. Descriptive statistics were employed to summarize the characteristics of the participants and their HRQOL. Multiple linear and logistic regression analyses were adopted to explore key factors affecting HRQOL.

RESULTS

A total of 329 valid questionnaires were collected. The mean (SD) age of the patients was 35.3 (10.0) years, with 52.3% of them being male. The patients reported more problems in Anxiety/Depression (81.5%) and Pain/Discomfort (69.9%) dimensions compared to the other three 5L dimensions. The mean (SD) of 5L health utility score (HUS) and EQ-VAS score were 0.76 (0.21) and 62.61 (19.20), respectively. According to multiple linear regression, initial symptoms (i.e., Anemia [fatigue, tachycardia, shortness of breath, headache] and back pain) and complication of thrombosis were significant influencing factors affecting 5L HUS. Total personal income of the past year, initial symptom of hemoglobinuria and complication of thrombosis were significantly influencing factors of VAS score. Social-demographic and clinical characteristics, such as gender, income, and thrombosis, were also found to be significantly related to certain 5L health problems as well.

CONCLUSION

Our study manifested the HRQOL of PNH patients in China was markedly compromised, especially in two mental-health related dimensions, and revealed several socio-demographic and clinical factors of their HRQOL. These findings could be used as empirical evidence for enhancing the HRQOL of PNH patients in China.

Real-world experience of pegcetacoplan in paroxysmal nocturnal hemoglobinuria

Pegcetacoplan significantly improves outcomes for patients with paroxysmal nocturnal hemoglobinuria (PNH) experiencing extravascular hemolysis (EVH) on eculizumab, leading to approval in 2021/2022 (USA/Europe). We report the first collaborative real-world evidence on pegcetacoplan use in UK and France. A total of 48 patients were either currently receiving or previously received pegcetacoplan (2019-2023). A total of 12 patients had participated in the PEGASUS clinical trial, continuing treatment after trial completion. Five patients were on combination treatment of C5 inhibition and pegcetacoplan. Mean pegcetacoplan duration was 20.2 months. Indication for pegcetacoplan was EVH on C5 inhibitors (Eculizumab, n = 29, Ravulizumab n = 16, others n = 3) with 35/48 patients requiring blood transfusion within the previous 12 months. Mean hemoglobin and reticulocyte count at pegcetacoplan commencement and after 3 months: 91 g/L and 205 × 109/L and 115.8 g/L and 107 × 109/L, respectively, resulting in mean Hb change of 22.3 g/L. Mean LDH pre- and post-pegcetacoplan was unchanged. Six patients have stopped pegcetacoplan. A total of 32 breakthrough hemolysis (BTH) events occurred in 13/48 patients. A total of 14 events were within clinical trials (reported separately). Six patients experienced 18 acute BTH events outside clinical trials, 7/18 associated with complement activating conditions. Successful clinical management included daily pegcetacoplan subcutaneously for 3 days or single eculizumab doses; these events are manageable with prompt intervention. Pegcetacoplan is effective for patients with PNH experiencing EVH. In this large patient cohort, treatment was well tolerated with improved hemoglobin and reticulocytes and maintained LDH control. Although BTH occurs, this is manageable by acute dose modification, with the majority of patients being maintained on pegcetacoplan.

Thrombosis and meningococcal infection rates in pegcetacoplan-treated patients with paroxysmal nocturnal hemoglobinuria in the clinical trial and postmarketing settings

Background

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired hematologic disease characterized by complement-mediated hemolysis and thrombosis. Complement component 5 (C5) inhibitors have decreased PNH-related thrombosis rates and reduced mortality compared with those of age-matched controls. A small but significantly increased risk of life-threatening Neisseria infections, especially N meningitidis, represents a long-term safety risk of complement inhibition.

Objectives

To evaluate the rates of thrombosis and meningococcal infections in patients with PNH treated with the complement component 3-targeted therapy pegcetacoplan.

Methods

Cumulative patient-year exposure to pegcetacoplan was calculated, and thrombotic events and meningococcal infections were reviewed in 7 clinical trials and in the postmarketing setting. The clinical trial protocols and pegcetacoplan labeling required vaccination against Streptococcus pneumoniae, N meningitidis, and Haemophilus influenzae before pegcetacoplan use; the label allowed for prophylactic antibiotic use if pegcetacoplan must be administered before vaccination.

Results

As of November 13, 2022, 464 patients with PNH had 619.4 patient-years of pegcetacoplan exposure in completed/ongoing clinical trials and the postmarketing setting. Seven thrombotic events were reported: 5 in clinical trials (2 in the same patient) and 2 in the postmarketing setting. The overall thrombosis rate was 1.13 events per 100 patient-years (clinical trials: 1.22 events/100 patient-years in 409.4 years; postmarketing: 0.95 events/100 patient-years in 210.0 years). No infections with meningococcal bacteria were reported.

Conclusion

Event rates for thrombosis were comparable between pegcetacoplan and previously reported rates of C5 inhibitors in patients with PNH, and no cases of meningococcal infection were reported with pegcetacoplan. Continued follow-up is required.

How We Interpret Thrombosis with Thrombocytopenia Syndrome?

Platelets play an important role in hemostasis, and a low platelet count usually increases the risk of bleeding. Conditions in which thrombosis occurs despite low platelet counts are referred to as thrombosis with thrombocytopenia syndrome, including heparin-induced thrombocytopenia, vaccine-induced immune thrombotic thrombocytopenia, paroxysmal nocturnal hemoglobinuria, antiphospholipid syndrome, thrombotic microangiopathy (TMA), and disseminated intravascular coagulation. TMA includes thrombotic thrombocytopenic purpura, Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (HUS), and atypical HUS. Patients with these pathologies present with thrombosis and consumptive thrombocytopenia associated with the activation of platelets and the coagulation system. Treatment varies from disease to disease, and many diseases have direct impacts on mortality and organ prognosis if therapeutic interventions are not promptly implemented. Underlying diseases and the results of physical examinations and general laboratory tests as part of a thorough workup for patients should promptly lead to therapeutic intervention before definitive diagnosis. For some diseases, the diagnosis and initial treatment must proceed in parallel. Utilization of not only laboratory tests but also various scoring systems is important for validating therapeutic interventions based on clinical information.

Abnormal expression of CUX1 influences autophagy activation in paroxysmal nocturnal hemoglobinuria

The mechanism underlying autophagy in paroxysmal nocturnal hemoglobinuria (PNH) remains largely unknown. We previously sequenced the entire genome exon of the CD59- cells from 13 patients with PNH and found genes such as CUX1 encoding Cut-like homeobox 1. Peripheral blood samples from 9 patients with PNH and 7 healthy control subjects were obtained to measure CUX1 expression. The correlation between CUX1 messenger RNA expression and PNH clinical indicators was analyzed. To simulate CUX1 expression in patients with PNH, we generated a panel of PNH cell lines by knocking out PIGA in K562 cell lines and transfected lentivirus with CUX1. CCK-8 and EDU assay assessed cell proliferation. Western blotting was used to detect Beclin-1, LC3A, LC3B, ULK1, PI3K, AKT, p-AKT, mTOR, and p-mTOR protein levels. Autophagosomes were observed with transmission electron microscopy. Chloroquine was used to observe CUX1 expression in PNH after autophagy inhibition. Leukocytes from patients with PNH had lower levels of CUX1 messenger RNA expression and protein content than healthy control subjects. The lactose dehydrogenase level and the percentage of PNH clones were negatively correlated with CUX1 relative expression. We reduced CUX1 expression in a PIGA knockout K562 cell line, leading to increased cell proliferation. Levels of autophagy markers Beclin-1, LC3B, LC3A, and ULK1 increased, and autophagosomes increased. Furthermore, PI3K/AKT/mTOR protein phosphorylation levels were lower. CUX1 expression did not change and cell proliferation decreased in CUX1 knocked down PNH cells after inhibition of autophagy by chloroquine. In brief, CUX1 loss-of-function mutation resulted in stronger autophagy in PNH.

Acute Necrotizing Pancreatitis Complicated with Paroxysmal Nocturnal Haemoglobinuria: A Case Report

This report presents a unique case of acute necrotizing pancreatitis(ANP) concomitant with paroxysmal nocturnal hemoglobinuria(PNH), a combination that has not been documented in existing literature. The impact of PNH on ANP and its treatment remains uncertain due to the lack of consensus. The case described herein involves a patient who exhibited both ANP and PNH, subsequently experiencing splanchnic vein thrombosis (SVT), resulting in substantial intra-abdominal and gastrointestinal hemorrhaging. We attempted to analyze the role of PNH in the formation of SVT in ANP and propose some new insights and hypotheses for the treatment of such patients.

FLAER as a standalone reagent for paroxysmal nocturnal hemoglobinuria: Do we need to reconsider the guidelines for testing?

INTRODUCTION

Flow cytometry-based paroxysmal nocturnal hemoglobinuria (PNH) testing involves utilization of monoclonal antibodies against GPI-linked proteins and FLAER. The ability of FLAER to bind to a wide variety of GPI-linked structures and to be utilized across different leukocyte subsets is remarkable. We hypothesize that FLAER as a standalone reagent may be equally effective for detecting PNH clones. The present study intends to compare the results of a FLAER alone-based strategy to the recommended FLAER+GPI-linked protein-based approach for applicability in clinical settings.

METHODS

EDTA-anticoagulated blood samples from patients for PNH workup were tested for PNH by multiparametric flow cytometry. A conventional panel comprising gating markers (CD45 for WBC, CD15 for granulocytes, and CD64 for monocytes) and a combination of FLAER and GPI-linked markers, such as CD24 and CD14, henceforth referred to as the "routine panel," was employed. Second, a "FLAER-only panel" comprising the gating markers and FLAER alone (excluding the GPI-linked markers CD24 and CD14) was set up. The samples were processed using the lyse-wash-stain-wash technique, and events were acquired on BC Navios Ex flow cytometer (Beckman Coulter, Inc., USA) and analyzed on Kaluza Software 2.1. The presence of a PNH clone was reported at a value of ≥0.01%.

RESULTS

A total of 209 patients were tested. Both panels found a PNH clone in 20.1% of patients (n = 42/209) with a 100% concordance rate. The PNH clone range for granulocytes was 0.01%-89.68%, and for monocyte was 0.04%-96.09% in the routine panel. The range in the FLAER-only panel for granulocytes was 0.01%-89.61%, and for monocytes, it was 0.01%-96.05%. Pearson correlation statistics revealed a significant correlation between the size of the PNH clone of granulocytes and monocytes among the two panels tested (granulocytes r = 0.9999, p < 0.0001, 95% CI = 0.9999 to 1.000; monocytes r = 0.9974, p < 0.0001, 95% CI = 0.9966-0.9980).

CONCLUSION

Based on our results, FLAER as a standalone marker is specific and sensitive for identifying PNH clones in granulocytes and monocytes, even for high-sensitivity PNH assay. The proposed "FLAER-only panel" panel is efficient and cost-effective for highly sensitive PNH testing in two different cell lineages, especially in resource-limited clinical settings.

Treatment outcomes of complement protein C5 inhibition in 509 UK patients with paroxysmal nocturnal hemoglobinuria

ABSTRACT

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematopoietic disorder that occurs on a background of bone marrow failure (BMF). In PNH, chronic intravascular hemolysis causes an increase in morbidity and mortality, mainly because of thromboses. Over the last 20 years, treatment of PNH has focused on the complement protein C5 to prevent intravascular hemolysis using the monoclonal antibody eculizumab and more recently ravulizumab. In the United Kingdom, all patients are under review at 1 of 2 reference centers. We report on all 509 UK patients with PNH treated with eculizumab and/or ravulizumab between May 2002 and July 2022. The survival of patients with eculizumab and ravulizumab was significantly lower than that of age- and sex-matched controls (P = .001). Only 4 patients died of thromboses. The survival of patients with PNH (n = 389), when those requiring treatment for BMF (clonal evolution to myelodysplastic syndrome or acute leukemia or had progressive unresponsive aplastic anemia) were excluded, was not significantly different from that of age- and sex-matched controls (P = .12). There were 11 cases of meningococcal sepsis (0.35 events per 100 patient-years). Extravascular hemolysis was evident in patients who received treatment, with 26.7% of patients requiring transfusions in the most recent 12 months on therapy. Eculizumab and ravulizumab are safe and effective therapies that reduce mortality and morbidity in PNH, but further work is needed to reduce mortality in those with concomitant BMF.

Impact of Lactate Dehydrogenase and Hemoglobin Levels on Clinical Outcomes in Patients With Paroxysmal Nocturnal Hemoglobinuria: Results From the National Korean PNH Registry

BACKGROUND

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematologic disorder caused by uncontrolled terminal complement activation, which leads to intravascular hemolysis (IVH), thromboembolism (TE), renal failure, and premature mortality.

METHODS

We performed a secondary analysis of data collected from patients enrolled in the Korean National PNH Registry to assess the relative importance of risk factors, specifically lactate dehydrogenase (LDH) and hemoglobin (Hb), in predicting the incidence of TE, impaired renal function, and death in complement inhibitor-naïve patients with PNH.

RESULTS

Multivariate regression modeling indicated that LDH ≥ 1.5 × upper limit of normal (ULN), male sex, and pain were associated with increased risk of TE (P = 0.016, 0.045, and 0.033, respectively), hemoglobinuria and pain were associated with an increased risk of impaired renal function (P = 0.034 and 0.022, respectively), and TE was associated with an increased incidence of death (P < 0.001). Hb < 8 g/dL was not a predictor of TE, impaired renal function, or death in multivariate regression analyses. Standardized mortality ratio analysis indicated that LDH ≥ 1.5 × ULN (P < 0.001), Hb < 8 g/dL (P < 0.001), and Hb ≥ 8 g/dL (P = 0.004) were all risk factors for death; in contrast, patients with LDH < 1.5 × ULN had similar mortality to the general population.

CONCLUSION

In complement inhibitor-naïve patients with PNH, LDH ≥ 1.5 × ULN was a significant predictor of TE, and TE was a significant predictor of death. Hb was not a significant predictor of TE, impaired renal function, or death. Therefore, controlling IVH will improve clinical outcomes for patients with PNH.

The disease burden of paroxysmal nocturnal hemoglobinuria in Denmark: Epidemiology, survival, healthcare resource utilization, costs, treatment gaps, and labor market attachment

OBJECTIVES

To establish epidemiology, healthcare costs, and labor market attachment in patients with paroxysmal nocturnal hemoglobinuria (Pt-PNH) in Denmark.

METHODS

Data were from Statistics Denmark and the Danish Health Data Authority national population registers (2005-2021). Descriptive baseline statistics characterized the Pt-PNH analytic population; ordinary least squares and adjusted Cox proportional hazards regressions measured outcomes in the Pt-PNH versus Danish general population matched comparators.

RESULTS

Overall PNH incidence in Denmark was n = 11 during 2007-2009, n = 25 during 2016-2018 and n = 7 during 2019-2020; prevalence increased from n = 13 in 2006 to n = 62 in 2021. Of the overall n = 85 Pt-PNH; n = 24 were treated with complement-5 inhibitors (Pt-C5i) and n = 61 not treated with C5i (Pt-nC5i). Versus respective comparators, all patients had significantly greater annual per-patient costs (from inpatient hospital admissions, outpatient contacts, PNH treatments; indirect costs from lost earnings + transfer payments; post-diagnosis for Pt-PNH and Pt-nC5i, post-treatment initiation for Pt-C5i). The Pt-C5i incurred the greatest healthcare and indirect cost differences (€709 119; €152 832, respectively) followed by the Pt-PNH (€189 323; €29 159, respectively) and Pt-nC5i (€95 548; €4713, respectively). The Pt-PNH versus comparators also had an increased hazard of death (2.71 [95% CI, 1.63 - 4.51]).

CONCLUSION

Although a rare disease, PNH is associated with significant patient, healthcare system, and societal burdens in Denmark.

Paroxysmal nocturnal hemoglobinuria: Review of the patient experience and treatment landscape

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disorder caused by complement-mediated hemolysis and thrombosis through the alternative pathway. The most common symptom of PNH is fatigue due to chronic anemia, which can negatively impact quality of life (QoL) and affect overall well-being. The currently approved therapies for PNH significantly limit intravascular hemolysis (IVH) and reduce the risk of thrombosis; however, they are associated with an infusion schedule that can become burdensome, and not all patients experience complete disease control. Several new complement inhibitors are in development that address the need for convenient routes of administration and aim to provide better disease control. With the variety of new treatment options on the horizon, hematologic markers as well as QoL concerns, patient opinion, and lifestyle factors should be considered to choose the optimal PNH treatment for each specific patient.

A Comprehensive Review of Risk Factors and Thrombophilia Evaluation in Venous Thromboembolism

Venous thromboembolism (VTE), which encompasses deep vein thrombosis (DVT) and pulmonary embolism (PE), is a significant cause of morbidity and mortality worldwide. There are many factors, both acquired and inherited, known to increase the risk of VTE. Most of these result in increased risk via several common mechanisms including circulatory stasis, endothelial damage, or increased hypercoagulability. Overall, a risk factor can be identified in the majority of patients with VTE; however, not all risk factors carry the same predictive value. It is important for clinicians to understand the potency of each individual risk factor when managing patients who have a VTE or are at risk of developing VTE. With this, many providers consider performing a thrombophilia evaluation to further define a patient's risk. However, guidance on who to test and when to test is controversial and not always clear. This comprehensive review attempts to address these aspects/concerns by providing an overview of the multifaceted risk factors associated with VTE as well as examining the role of performing a thrombophilia evaluation, including the indications and timing of performing such an evaluation.

Predictors for improvement in patient-reported outcomes: post hoc analysis of a phase 3 randomized, open-label study of eculizumab and ravulizumab in complement inhibitor-naive patients with paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by uncontrolled terminal complement activation leading to intravascular hemolysis (IVH), thrombosis, and impairments in quality of life (QoL). The aim of this study was to identify the clinical drivers of improvement in patient-reported outcomes (PROs) in patients with PNH receiving the complement component 5 (C5) inhibitors eculizumab and ravulizumab.This post hoc analysis assessed clinical outcomes and PROs from 246 complement inhibitor-naive patients with PNH enrolled in a phase 3 randomized non-inferiority study that compared the C5 inhibitors ravulizumab and eculizumab (study 301; NCT02946463). The variables of interest were lactate dehydrogenase (LDH) levels, a surrogate measure of IVH, and hemoglobin (Hb) levels. PROs were collected using Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) and European Organisation for Research and Treatment of Cancer, Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) to assess fatigue and QoL, respectively.Improvements in absolute mean LDH levels were significantly associated with improvements in mean FACIT-F score (p = 0.0024) and EORTC QLQ-C30 global health (GH) score (p < 0.0001) from baseline to day 183. Improvements in scores were achieved despite a non-significant increase in Hb levels. To understand the interaction between LDH and Hb, a regression analysis was performed: LDH response with Hb improvements was a significant predictor of improvement in fatigue. The independent effect of improved Hb did not significantly affect FACIT-F or EORTC QLQ-C30 GH scores.These findings suggest that LDH levels are an important determinant of fatigue and QoL outcomes in patients with PNH. CTR: NCT02946463, October 27, 2016.

Addition of danicopan to ravulizumab or eculizumab in patients with paroxysmal nocturnal haemoglobinuria and clinically significant extravascular haemolysis (ALPHA): a double-blind, randomised, phase 3 trial

BACKGROUND

Symptoms of anaemia due to clinically significant extravascular haemolysis can affect patients with paroxysmal nocturnal haemoglobinuria (PNH) treated with C5 inhibitors (ravulizumab or eculizumab). The aim of this study was to assess the efficacy and safety of danicopan (ALXN2040), an investigational, first-in-class, oral complement factor D inhibitor, as add-on therapy to ravulizumab or eculizumab in patients with PNH and clinically significant extravascular haemolysis.

METHODS

ALPHA is an ongoing, international, phase 3, randomised, double-blind, placebo-controlled trial evaluating danicopan as add-on therapy to ravulizumab or eculizumab. Eligible patients were adults (age ≥18 years) with PNH and clinically significant extravascular haemolysis (haemoglobin ≤9·5 g/dL; absolute reticulocyte count ≥120 × 109/L) on ravulizumab or eculizumab for at least 6 months. Patients were randomly assigned (2:1) to danicopan or placebo added to ravulizumab or eculizumab for 12 weeks using an interactive response technology system. Randomisation was stratified based on transfusion history, haemoglobin, and patients enrolled from Japan. The initial oral danicopan dose was 150 mg three times a day; escalation to 200 mg three times a day was permitted based on clinical response. The infusion dose level of eculizumab (every 2 weeks) ranged from 900 mg to 1500 mg, and for ravulizumab (monthly or every 8 weeks) ranged from 3000 mg to 3600 mg. The primary endpoint was change in haemoglobin concentration from baseline to week 12. Here we present the protocol-prespecified interim analysis, planned when approximately 75% of participants were randomly assigned to treatment and completed or discontinued at 12 weeks. This trial is registered with ClinicalTrials.gov (NCT04469465).

FINDINGS

Individuals were randomly assigned between Dec 16, 2020, and Aug 29, 2022. At data cutoff (June 28, 2022), 73 individuals were randomly assigned, received treatment, and were analysed for safety (danicopan, n=49; placebo, n=24). The protocol-prespecified interim efficacy analysis set included the first 63 participants (danicopan, n=42; placebo, n=21). At week 12, danicopan plus ravulizumab or eculizumab increased haemoglobin versus placebo plus ravulizumab or eculizumab (least squares mean [LSM] change from baseline: danicopan, 2·94 g/dL [95% CI 2·52 to 3·36]; placebo, 0·50 g/dL [-0·13 to 1·12]; LSM difference, 2·44 g/dL [1·69 to 3·20]; p<0·0001). Grade 3 adverse events in the danicopan group were increased alanine aminotransferase (two [4%] of 49 patients), leukopenia (one [2%]), neutropenia (two [4%]), cholecystitis (one [2%]), COVID-19 (one [2%]), increased aspartate aminotransferase (one [2%]), and increased blood pressure (one [2%]), and in the placebo group were anaemia (one [4%] of 24 patients), thrombocytopenia (one [4%]), and asthenia (one [4%]). The serious adverse events reported in the danicopan group were cholecystitis (one [2%] patient) and COVID-19 (one [2%]) and in the placebo group were anaemia and abdominal pain, both in one (4%) patient. There were no serious adverse events related to study drug or deaths reported in the study.

INTERPRETATION

These primary efficacy and safety results show that danicopan as add-on treatment to ravulizumab or eculizumab significantly improved haemoglobin concentrations at week 12 with no new safety concerns, suggesting an improved benefit-risk profile in patients with PNH and clinically significant extravascular haemolysis.

FUNDING

Alexion, AstraZeneca Rare Disease.

Cost-effectiveness of ravulizumab compared with eculizumab for the treatment of paroxysmal nocturnal hemoglobinuria in the Netherlands

OBJECTIVES

The aim of this study was to evaluate the cost-effectiveness of ravulizumab compared with eculizumab for the treatment of adult patients with paroxysmal nocturnal hemoglobinuria (PNH) in the Netherlands.

METHODS

A cost-effectiveness analysis was conducted based on a Markov cohort model simulating the course of patients with PNH with clinical symptom(s) indicative of high disease activity, or who are clinically stable after having been treated with eculizumab for at least the past six months. Costs, quality of life, and the incremental cost-effectiveness ratio (ICER) were estimated over a lifetime horizon from a Dutch societal perspective. Several additional analyses were performed, including a one-way sensitivity analysis, a probabilistic sensitivity analysis, and scenario analysis.

RESULTS

When compared with eculizumab, ravulizumab saves €266,833 and 1.57 quality adjusted life years (QALYs) are gained, resulting in a dominant ICER. Drug costs account for the majority of the total costs in both intervention groups. Cost savings were driven by the difference in total treatment costs of ravulizumab compared with eculizumab caused by the reduced administration frequency, accounting for 98% of the total cost savings. The QALY gain with ravulizumab is largely attributable to the improved quality of life associated with less frequent infusions and BTH events. At a willingness-to-pay threshold of €20,000/QALY, there is a 76.6% probability that ravulizumab would be cost-effective.

CONCLUSIONS

The cost reduction and QALY gain associated with the lower rates of BTH and less frequent administration make ravulizumab a cost-saving and clinically beneficial substitute for eculizumab for adults with PNH in the Netherlands.

Long-term effectiveness of eculizumab: Data from the International PNH Registry

OBJECTIVES

Data from the International PNH Registry (NCT01374360) were used to estimate the overall survival and first occurrence of thromboembolic events/major adverse vascular events (TEs/MAVEs) for eculizumab-treated patients with paroxysmal nocturnal hemoglobinuria (PNH) compared with a contemporaneous untreated cohort.

METHODS

Patients enrolled in the Registry from March 16, 2007, to February 14, 2022, were included. Treated patients received eculizumab for >35 days; untreated patients did not receive eculizumab at any time. Univariable and multivariable analyses were performed using a Cox proportional hazards regression model comparing eculizumab treatment periods to untreated periods and were adjusted for baseline covariates (e.g., high disease activity [HDA], transfusion dependency, and eculizumab treatment status).

RESULTS

The analysis included 4118 patients. The univariable hazard ratio (HR) (95% CI) for mortality in eculizumab-treated time versus untreated time was 0.51 (0.41-0.64; p < 0.0001). Significant baseline covariates included age, sex, history of bone marrow failure, ≥4 erythrocyte transfusions within 12 months before baseline, and an estimated glomerular filtration rate ≤ 60 mL/min/1.73 m2 (all p < 0.0001). In the adjusted analysis, patients with baseline HDA had the greatest reduction in mortality risk (HR [95% CI], 0.51 [0.36-0.72]). Treated patients had approximately 60% reduction in TE/MAVE risk during treated versus untreated time (HR [95% CI]: TE: 0.40 [0.26-0.62], MAVE: 0.37 [0.26-0.54]; p < 0.0001).

CONCLUSION

Using data from the largest Registry of patients with PNH, with ≥14 years of overall follow-up, we demonstrate that treatment with eculizumab conferred a 49% relative benefit in survival and an approximately 60% reduction in TE/MAVE risk.

Leukemic transformation during anti-tuberculosis treatment in aplastic anemia-paroxysmal nocturnal hemoglobinuria syndrome: A case report and review of literature

BACKGROUND

Accumulating evidence demonstrates that autoimmune hematopoietic failure and myeloid neoplasms have an intrinsic relationship with regard to clonal hematopoiesis and disease evolution. In approximately 10%-15% of patients with severe aplastic anemia (SAA), the disease phenotype is transformed into myeloid neoplasms following antithymocyte globulin plus cyclosporine-based immunosuppressive therapy. In some of these patients, myeloid neoplasms appear during or shortly after immunosuppressive therapy. Leukemic transformation in SAA patients during anti-tuberculosis treatment has not been reported.

CASE SUMMARY

A middle-aged Chinese female had a 6-year history of non-SAA and a 2-year history of paroxysmal nocturnal hemoglobinuria (PNH). With aggravation of systemic inflammatory symptoms, severe pancytopenia developed, and her hemoglobinuria disappeared. Laboratory findings in cytological, immunological and cytogenetic analyses of bone marrow samples met the diagnostic criteria for "SAA." Definitive diagnosis of disseminated tuberculosis was made in the search for infectious niches. Remarkable improvement in hematological parameters was achieved within 1 mo of anti-tuberculosis treatment, and complete hematological remission was achieved within 4 mo of treatment. Frustratingly, the hematological response lasted for only 3 mo, and pancytopenia reemerged. At this time, cytological findings (increased bone marrow cellularity and an increased percentage of myeloblasts that accounted for 16.0% of all nucleated hematopoietic cells), immunological findings (increased percentage of cluster of differentiation 34+ cells that accounted for 12.28% of all nucleated hematopoietic cells) and molecular biological findings (identification of somatic mutations in nucleophosmin-1 and casitas B-lineage lymphoma genes) revealed that "SAA" had transformed into acute myeloid leukemia with mutated nucleophosmin-1. The transformation process suggested that the leukemic clones were preexistent but were suppressed in the PNH and SAA stages, as development of symptomatic myeloid neoplasm through acquisition and accumulation of novel oncogenic mutations is unlikely in an interval of only 7 mo. Aggravation of inflammatory stressors due to disseminated tuberculosis likely contributed to the repression of normal and leukemic hematopoiesis, and the relief of inflammatory stressors due to anti-tuberculosis treatment contributed to penetration of neoplastic hematopoiesis. The concealed leukemic clones in the SAA and PNH stages raise the possibility of an inflammatory stress-fueled antileukemic mechanism.

CONCLUSION

Aggravated inflammatory stressors can repress normal and leukemic hematopoiesis, and relieved inflammatory stressors can facilitate penetration of neoplastic hematopoiesis.

Cerebral venous thrombosis in patients with autoimmune disease, hematonosis or coronavirus disease 2019: Many familiar faces and some strangers

BACKGROUND

Cerebral venous thrombosis, a rare stroke, is characterized by neurological dysfunction caused by bleeding and/or infarction resulting from venous sinus thrombosis, the so-called venous stroke. Current guidelines recommend anticoagulants as first-line therapy in the treatment of venous stroke. With complicated causes of cerebral venous thrombosis, treatment is difficult, especially when combined with autoimmune diseases, blood diseases, and even COVID-19.

AIMS

This review summarizes the pathophysiological mechanisms, epidemiology, diagnosis, treatment, and clinical prognosis of cerebral venous thrombosis combined with autoimmune diseases, blood diseases, or infectious diseases such as COVID-19.

CONCLUSION

A systematic understanding of particular risk factors that should not be neglected when unconventional cerebral venous thrombosis occurs and for a scientific understanding of pathophysiological mechanisms, clinical diagnosis, and treatment, thus contributing to knowledge on special types of venous stroke.

Early Mortality in Paroxysmal Nocturnal Hemoglobinuria

OBJECTIVES

 The elevated mortality risk among patients with paroxysmal nocturnal hemoglobinuria (PNH) has been suggested to derive from a high risk of thromboembolism (TE); however, the risks of coexisting cardiovascular risk factors are not well described. We studied mortality associated with PNH taking comorbidity and treatment into account.

METHODS

Patients with PNH (n=115) were identified in the 1977-2016 Danish National Patient Register (DNPR). For each patient with PNH, we identified 50 age- and sex-matched general population comparators. Using the Kaplan-Meier estimator and Cox regression, we compared the overall survival of patients with comparators. Cumulative incidences were used to analyze the effects of comorbidity and the causes of death.

RESULTS

One-year survival among patients and comparators was 92.2% and 99.4%, and after 10 years, it was 68.4% and 85.8%, respectively. Early mortality was associated with older age, higher levels of comorbidity, and solid malignancies prior to PNH diagnosis. The leading causes of death were infections and associated hematological diseases. Patients with early mortality were less likely to have received treatment with eculizumab and/or warfarin. Cardiovascular risk factors were evenly distributed between patients and comparators at diagnosis.

CONCLUSION

We conclude that early mortality in PNH is associated with older age, cardiovascular comorbidity, and hematological malignancies.

The cost-effectiveness of pegcetacoplan in complement treatment-naïve adults with paroxysmal nocturnal hemoglobinuria in the USA

Aim: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare blood disorder characterized by hemolytic anemia, bone marrow failure and thrombosis, and is associated with high healthcare burden. We evaluated the cost-effectiveness of pegcetacoplan, a proximal complement-3 inhibitor (C3i), compared with the C5i, eculizumab and ravulizumab, in complement treatment-naive adults with PNH, from the US healthcare payer perspective. Materials & methods: A de novo cost-effectiveness model based on a Markov cohort structure evaluated lifetime (55-year) PNH costs and outcomes. The 6-month cycles of the model reflected the follow-up period of PRINCE (NCT04085601), an open-label trial of pegcetacoplan compared with eculizumab in C5i-naive patients. Data from PRINCE informed the clinical, safety and health-related quality of life outcomes in the model. Results: Pegcetacoplan was associated with lifetime cost savings of USD1,176,808 and USD213,062 relative to eculizumab and ravulizumab, respectively (largely attributed to reduced drug costs and blood transfusions), and additional quality-adjusted life years (QALYs) of 0.25 and 0.24. Conclusion: In patients with PNH who are treatment-naive, the base-case cost-effectiveness analysis, scenario analysis and sensitivity analysis showed both lifetime cost savings and increased QALYs associated with pegcetacoplan compared with eculizumab or ravulizumab in the USA.

Paroxysmal Nocturnal Hemoglobinuria: Biology and Treatment

Paroxysmal nocturnal hemoglobinuria (PNH) is a nonmalignant clonal hematopoietic disorder characterized by the lack of glycosylphosphatidylinositol-anchored proteins (GPI-APs) as a consequence of somatic mutations in the phosphatidylinositol glycan anchor biosynthesis class A (PIGA) gene. Clinical manifestations of PNH are intravascular hemolysis, thrombophilia, and bone marrow failure. Treatment of PNH mainly relies on the use of complement-targeted therapy (C5 inhibitors), with the newest agents being explored against other factors involved in the complement cascade to alleviate unresolved intravascular hemolysis and extravascular hemolysis. This review summarizes the biology and current treatment strategies for PNH with the aim of reaching a general audience with an interest in hematologic disorders.

Efficacy and safety of the C5 inhibitor crovalimab in complement inhibitor-naive patients with PNH (COMMODORE 3): A multicenter, Phase 3, single-arm study

The Phase 3 single-arm COMMODORE 3 study (ClinicalTrials.gov, NCT04654468) evaluated efficacy and safety of crovalimab (novel C5 inhibitor) in complement inhibitor-naive patients with paroxysmal nocturnal hemoglobinuria (PNH). COMMODORE 3 enrolled patients from five China centers. Eligible complement inhibitor-naive patients with PNH were ≥12 years old, had lactate dehydrogenase (LDH) ≥2 × upper limit of normal (ULN), and had ≥4 transfusions of packed red blood cells within the prior 12 months. Patients received crovalimab loading doses (one intravenous, four subcutaneous) and subsequent every-4-weeks subcutaneous maintenance doses per weight-based tiered-dosing schedule. Co-primary efficacy endpoints were mean proportion of patients with hemolysis control (LDH ≤1.5 × ULN) from Week (W)5 through W25 and difference in proportion of patients with transfusion avoidance from baseline through W25 versus within 24 weeks of prescreening in patients who had ≥1 crovalimab dose and ≥1 central LDH assessment after first dose. Between March 17 and August 24, 2021, 51 patients (15-58 years old) were enrolled; all received treatment. At primary analysis, both co-primary efficacy endpoints were met. Estimated mean proportion of patients with hemolysis control was 78.7% (95% CI: 67.8-86.6). Difference between proportion of patients with transfusion avoidance from baseline through W25 (51.0%; n = 26) versus within 24 weeks of prescreening (0%) was statistically significant (p < .0001). No adverse events led to treatment discontinuation. One treatment-unrelated death (subdural hematoma following a fall) occurred. In conclusion, crovalimab, with every-4-weeks subcutaneous dosing is efficacious and well tolerated in complement inhibitor-naive patients with PNH.

Characteristics of paroxysmal nocturnal hemoglobinuria patients in Brazil: A retrospective administrative claims database analysis of PNH patients in Brazilian public healthcare system

INTRODUCTION

Few studies have reported the profile of patients with paroxysmal nocturnal hemoglobinuria (PNH) and their care in the Brazilian health system.

OBJECTIVE

To describe clinical and epidemiological characteristics of patients with PNH in the Brazilian public health system including procedures performed, associated comorbidities and visits to health care professionals.

METHODS

In a real-world observational, retrospective, population-based cohort study, anonymized secondary data provided by the Department of Informatics of the Brazilian Unified Health System (DATASUS) were analyzed. Patients were considered eligible if they had at least one procedure coded with the ICD-10 code D59.5 from January 1, 2008 to December 30, 2018.

RESULTS

In total, 675 individual PNH patients were identified (52.4% female; prevalence of 1:237,000 people). Around 15.8% of the patients included had myelodysplastic syndrome and about half of the sample had other aplastic anemias and/or other bone marrow failure syndromes. Portal vein thrombosis (I82 ICD code) was reported in 4.3% of patients. Regarding hospitalizations, 263 individual PNH patients had 416 inpatient admissions with the ICD code for PNH (D59.5) on admission. Twelve deaths occurred during the study period, of which two had the PNH ICD code related with the cause of death, while another three deaths were associated with acquired hemolytic anemia (D59.9), unspecified aplastic anemia (D61.9) and acute respiratory failure (J96.0), respectively.

CONCLUSION

Despite its limitations, this statistical analysis of data extracted from DATASUS reasonably describes PNH patients in Brazil and its variations across different regions of the country. Comorbidities frequently associated with PNH such as portal vein thrombosis were not as common in our study, but it is assumed that several thrombotic events at specific sites were coded under the broader I82 ICD code. The frequency of visits to different health professionals, including hematologists, increased after the diagnosis of PNH. Among hospitalized PNH patients, the mortality rate was 4.5%.

Swiss Survey on current practices and opinions on clinical constellations triggering the search for PNH clones

This national survey investigated the current practice in Switzerland by collecting participants' opinions on paroxysmal nocturnal hemoglobinuria (PNH) clone assessment and clinical practice.

Aim

This study aimed to investigate clinical indications prompting PNH clones' assessment and physician's accessibility of a flow cytometry facility, and also to understand clinical attitudes on the follow-up (FU) of patients with PNH clones.

Methods

The survey includes 16 multiple-choice questions related to PNH and targets physicians with a definite level of experience in the topic using two screener questions. Opinion on clinical management was collected using hypothetical clinical situations. Each participant had the option of being contacted to further discuss the survey results. This was an online survey, and 264 physicians were contacted through email once a week for 5 weeks from September 2020.

Results

In total, 64 physicians (24.2%) from 23 institutions participated (81.3% hematologists and 67.2% from university hospitals). All had access to flow cytometry for PNH clone testing, with 76.6% having access within their own institution. The main reasons to assess for PNH clones were unexplained thrombosis and/or hemolysis, and/or aplastic anemia (AA). Patients in FU for PNH clones were more likely to be aplastic anemia (AA) and symptomatic PNH. In total, 61% of the participants investigated PNH clones repetitively during FU in AA/myelodysplastic syndromes patients, even when there was no PNH clone found at diagnosis, and 75% of the participants tested at least once a year during FU. Opinions related to clinical management were scattered.

Conclusion

The need to adhere to guidelines for the assessment, interpretation, and reporting of PNH clones emerges as the most important finding, as well as consensus for the management of less well-defined clinical situations. Even though there are several international guidelines, clear information addressing specific topics such as the type of anticoagulant to use and its duration, as well as the indication for treatment with complement inhibitors in some borderline situations are needed. The analysis and the discussion of this survey provide the basis for understanding the unmet needs of PNH clone assessment and clinical practice in Switzerland.

Clinically important change for the FACIT-Fatigue scale in paroxysmal nocturnal hemoglobinuria: a derivation from international PNH registry patient data

BACKGROUND

Fatigue is the most common symptom associated with paroxysmal nocturnal hemoglobinuria (PNH). The objective of this analysis was to estimate values that would suggest a clinically important change (CIC) for the functional assessment of chronic illness therapy-fatigue scale (FACIT-Fatigue) in patients with PNH.

METHODS

Adults with PNH who initiated eculizumab within 28 days of enrollment in the International PNH Registry as of January 2021 with baseline FACIT-Fatigue scores were included in the analysis. Distribution-based estimates of likely difference were calculated using 0.5 × SD and SEM. Anchor-based estimates of CIC considered the European Organization for Research and Treatment of Cancer (EORTC) global health status/quality of life summary score and the EORTC Fatigue Scale score. Changes in anchors and high disease activity (HDA) shift from start of eculizumab treatment to each follow-up visit were then assessed by FACIT-Fatigue score change (≤ 1 CIC, no change, or ≥ 1 CIC).

RESULTS

At baseline, 93% of 423 patients had fatigue documented in their medical history. The distribution-based estimates for FACIT-Fatigue were 6.5 using 0.5 × SD and 4.6 using SEM; internal consistency was high (α = 0.87). For anchor-based estimates, the FACIT-Fatigue CIC ranged from 2.5 to 15.5, and generally supported 5 points as a reasonable lower end of the value for meaningful individual change. The percentage of patients who changed from having HDA at baseline to no HDA at eculizumab-treated follow-up visits increased over time.

CONCLUSION

These results support the use of 5 points as the CIC for FACIT-Fatigue in patients with PNH, which is within range of the CICs reported in other diseases (3-5 points).

Relationship of paroxysmal nocturnal hemoglobinuria (PNH) granulocyte clone size to disease burden and risk of major vascular events in untreated patients: results from the International PNH Registry

Paroxysmal nocturnal hemoglobinuria (PNH) is caused by acquired gene mutations resulting in deficiency of glycosylphosphatidylinositol (GPI)-anchored complement regulatory proteins on the surface of blood cells, leading to terminal complement-mediated intravascular hemolysis and increased risk of major adverse vascular events (MAVEs). Using data from the International PNH Registry, this study investigated the relationship between the proportion of GPI-deficient granulocytes at PNH onset and (1) the risk for MAVEs (including thrombotic events [TEs]) and (2) the following parameters at last follow-up: high disease activity (HDA); lactate dehydrogenase (LDH) ratio; fatigue; abdominal pain; and rates of overall MAVEs and TEs. A total of 2813 patients untreated at enrollment were included and stratified by clone size at PNH disease onset (baseline). At last follow-up, higher proportion of GPI-deficient granulocytes (≤ 5% vs. > 30% clone size) at baseline was associated with significantly increased HDA incidence (14% vs. 77%), mean LDH ratio (1.3 vs. 4.7 × upper limit of normal), and rates of MAVEs 1.5 vs. 2.9 per 100 person-years) and TEs (0.9 vs. 2.0 per 100 person-years). Fatigue was evident in 71 to 76% of patients regardless of clone size. Abdominal pain was more frequently reported with clone size > 30%. A larger clone size at baseline appears to indicate a greater disease burden and risk of TEs and MAVEs and may inform decision making among physicians managing PNH patients at risk of experiencing TEs or other MAVEs. ClinicalTrials.gov ID: NCT01374360.

The Effect of Respiratory Viral Infections on Breakthrough Hemolysis in Patients with Paroxysmal Nocturnal Hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by hemolysis and thrombosis and is associated with significant morbidity and mortality. Although complement inhibitors have significantly changed the outcomes in PNH patients, breakthrough hemolysis (BTH) may still occur as a response to stress factors such as pregnancy, surgery, and infections. Despite the well-described association between bacterial infections and hemolysis in PNH patients, little is known about the effect of respiratory viruses on triggering hemolytic episodes. This is the first study, to our knowledge, addressing this question. We retrospectively analyzed 34 patients with PNH disease between 2016 and 2018, who were on eculizumab treatment and who presented with respiratory symptoms and were subsequently tested for 10 respiratory viruses (influenza A, influenza B, parainfluenza, respiratory syncytial virus, adenovirus, rhinovirus, and human metapneumovirus). NTS+ patients had higher inflammatory markers, with the majority requiring antibiotics. Acute hemolysis, along with a significant drop in hemoglobin, was noted in the NTS+ group, with three of them requiring a top-up transfusion and two requiring an extra dose of eculizumab. Furthermore, the time from the last eculizumab dose was longer in the NTS+ patients who had BTH, than those who did not. Our data indicate that respiratory virus infections pose a significant risk for BTH in PNH patients on complement inhibitor treatment, underlining the need for regular screening and close monitoring of patients with respiratory symptoms. Furthermore, it implies a higher risk for patients who are not established on complement inhibitors, suggesting the necessity for greater vigilance in these patients.

Pegcetacoplan for Treating Paroxysmal Nocturnal Haemoglobinuria: An Evidence Review Group Perspective of a NICE Single Technology Appraisal

As part of the Single Technology Appraisal (STA) process, the UK National Institute for Health and Care Excellence (NICE) invited Apellis Pharmaceuticals/Sobi to submit evidence for the clinical and cost effectiveness of pegcetacoplan versus eculizumab and pegcetacoplan versus ravulizumab for treating paroxysmal nocturnal haemoglobinuria (PNH) in adults whose anaemia is uncontrolled after treatment with a C5 inhibitor. The Liverpool Reviews and Implementation Group at the University of Liverpool was commissioned as the Evidence Review Group (ERG). The company pursued a low incremental cost-effectiveness ratio (ICER) Fast Track Appraisal (FTA). This was a form of STA processed in a shorter time frame and designed for technologies with company base-case ICER < £10,000 per quality-adjusted life-year (QALY) gained and most plausible ICER < £20,000 per QALY gained. This article summarises the ERG's review of the company's evidence submission, and the NICE Appraisal Committee's (AC's) final decision. The company presented clinical evidence from the PEGASUS trial that assessed the efficacy of pegcetacoplan versus eculizumab. At Week 16, patients in the pegcetacoplan arm had statistically significantly greater change from baseline in haemoglobin levels and a higher rate of transfusion avoidance than patients in the eculizumab arm. Using the PEGASUS trial and Study 302 data (a non-inferiority trial that assessed ravulizumab versus eculizumab), the company conducted an anchored matching-adjusted indirect comparison (MAIC) to indirectly estimate the efficacy of pegcetacoplan versus ravulizumab. The company identified key differences between trial designs and populations that could not be adjusted for using anchored MAIC methods. The company and ERG agreed that the anchored MAIC results were not robust and should not inform decision making. In the absence of robust indirect estimates, the company assumed that ravulizumab had equivalent efficacy to eculizumab in the PEGASUS trial population. Results from the company base-case cost-effectiveness analysis showed that treatment with pegcetacoplan dominated eculizumab and ravulizumab. The ERG considered that the long-term effectiveness of pegcetacoplan was uncertain and ran a scenario assuming that after 1 year the efficacy of pegcetacoplan would be the same as eculizumab; treatment with pegcetacoplan continued to dominate eculizumab and ravulizumab. The AC noted that treatment with pegcetacoplan had lower total costs than treatment with eculizumab or ravulizumab because it is self-administered and reduces the need for blood transfusions. If the assumption that ravulizumab has equivalent efficacy to eculizumab does not hold, then this will affect the estimate of the cost effectiveness of pegcetacoplan versus ravulizumab; however, the AC was satisfied that the assumption was reasonable. The AC recommended pegcetacoplan as an option for the treatment of PNH in adults who have uncontrolled anaemia despite treatment with a stable dose of a C5 inhibitor for ≥ 3 months. Pegcetacoplan was the first technology recommended by NICE via the low ICER FTA process.

Pharmacological and clinical profile of ravulizumab 100 mg/mL formulation for paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome

INTRODUCTION

Paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS) are two rare and severe conditions caused by chronic complement (C') system dysregulation. Treatment with eculizumab, a recombinant, humanized monoclonal antibody against complement C5, changed the natural history of both diseases inducing remission and improving patient outcome. Ravulizumab, a new long-acting next-generation C5 inhibitor has been recently approved for treatment of PNH and aHUS.

AREAS COVERED

Main characteristics of ravulizumab are described: composition, dosing, efficacy and safety profile. Further, an overview of seminal studies and clinical trials using ravulizumab to treat PNH and aHUS in children and adults is detailed. Literature review was performed using the following key words: paroxysmal nocturnal hemoglobinuria, atypical hemolytic uremic syndrome, and ravulizumab.

EXPERT OPINION

Ravulizumab profile to treat PNH and aHUS is equivalent to eculizumab in efficacy and safety but allows extended dosing interval to every 4-8 weeks based on patient weight, and requires reduced infusion time. Less travels to infusion centers and medical visits and decreasing job and school absences, significantly increases patient and families' QoL, while reducing cost. Further infusion time is reduced Ravulizumab will possibly become the treatment of choice for patients with PNH and aHUS on chronic C5 inhibition.

Mapping the EORTC QLQ-C30 onto the EQ-5D-5L index for patients with paroxysmal nocturnal hemoglobinuria in France

Aim: To map patient-level data collected on the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC) QLQ-C30 to EQ-5D-5L data for estimating health-state utilities in patients with paroxysmal nocturnal hemoglobinuria (PNH). Materials & methods: European cross-sectional PNH patient survey data populated regression models mapping EORTC QLQ-C30 domains (covariates: sex and baseline age) to utilities calculated with the EQ-5D-5L French value set. A genetic algorithm allowed selection of the best-fitting between a set of models with and without interaction terms. We validated the selected algorithm using EQ-5D-5L utilities converted from EORTC QLQ-C30 data collected in the PEGASUS phase III, randomized controlled trial of pegcetacoplan versus eculizumab in adults with PNH. Results: Selected through the genetic algorithm, the ordinary least squares model without interactions provided highly stable results across study visits (mean [±SD] utilities 0.58 [±0.42] to 0.89 [±0.10]), and showed the best predictive validity. Conclusion: The new PNH EQ-5D-5L direct mapping developed using a genetic algorithm enabled calculation of reliable health-state utility data required for cost-utility analysis in health technology assessments supporting treatments of PNH.

Pegcetacoplan: A New Opportunity for Complement Inhibition in PNH

Pegcetacoplan is the newest inhibitor of the complement system to be approved by the FDA and EMA for the treatment of Paroxysmal Nocturnal Hemoglobinuria (PNH). The cyclic peptide inhibitor of C3 was evaluated in several clinical trials in PHN leading to its approval. The focus of this paper will review the efficacy and safety of Pegcetacoplan (PEG), and considerations for use in patients with PNH.

A Review of Systemic Hematological Manifestations and Stent Thrombosis

Stent thrombosis (ST) has significant morbidity and mortality following percutaneous coronary intervention (PCI). ST is uncommon making the identification of nonprocedural predictors challenging. Numerous case reports of ST in both benign and malignant hematological conditions exist. Given ST could be a Herald event of an undiagnosed condition and condition-specific treatment may be available, it is important to consider specialist testing in an unexplained ST. This review included a case presentation of ST in previously undiagnosed paroxysmal nocturnal hemoglobinuria (PNH) and a literature review of ST in other acquired thrombophilias including myeloproliferative disorders (MPNs), antiphospholipid syndrome, hematological malignancies, and heparin-induced thrombocytopenia (HIT). Inherited thrombophilias and common pitfalls in thrombophilia and coagulation testing are also discussed. The cardiac-hematology landscape is becoming increasingly complex and there is a paucity of how to best manage ST in these patients. There is clear variability in practice and the use of multidisciplinary input between cardiologists and hematologists is essential.

Nationwide study of eculizumab in paroxysmal nocturnal hemoglobinuria: Evaluation of treatment indications and outcomes

Eculizumab is an effective treatment for paroxysmal nocturnal hemoglobinuria (PNH). However, considering the risk of life-threatening meningococcal disease, life-long duration and costs, there are strict criteria for initiation of therapy. To evaluate the application and real-world effectiveness of eculizumab in the Netherlands, a multicenter retrospective cohort study was conducted: indications and treatment outcomes were collected for 105 Dutch PNH patients. In all patients, eculizumab was initiated conforming to indications as formulated in the Dutch PNH guideline. According to recently published response criteria, 23.4% of the patients had reached a complete hematological response, 53.2% a good or partial response, and 23.4% a minor response after 12 months of therapy. In the majority of patients the response remained stable during long-term follow-up. The degree and relevance of extravascular hemolysis significantly differed between response groups (p = 0.002). Improvements of EORTC-QLQc30 and FACIT-fatigue scores were observed, however patients reported lower scores than the general population. A detailed evaluation of 18 pregnancies during eculizumab showed no maternal or fetal deaths, and no thromboembolic events during pregnancy. This study demonstrates that the majority of patients benefit from eculizumab when adhering to the indications as formulated in the Dutch PNH guideline. However, novel therapies are needed to further improve real-world outcomes, such as hematological responses and quality of life.

From bone marrow failure syndromes to VEXAS: Disentangling clonal hematopoiesis, immune system, and molecular drivers

Clonal hematopoiesis (CH) is a result of the selective expansion of hematopoietic stem and progenitor cells (HSPCs) carrying somatic mutations originating from a primary HSC. The advent of modern genomic technologies has helped recognizing that CH is common in elderly healthy subjects as a result of the aging bone marrow (BM). CH in healthy subjects without abnormalities in blood counts is known as CH of indeterminate potential. CH is also seen in BM failure (BMF) disorders. Whether CH alarms for the risk to develop malignant evolution in BMF or creates an adaptation to selective pressure is a matter of controversy. As such, a continuum might exist from pre-malignant to malignant hematopoietic diseases. This review summarizes how somatic mutations and immune derangement in HSCs shape disease evolution and describes the complexity of disorders such as VEXAS as the prototypic tetrad of somatic mutations, morphologic features, inflammatory pathways and immune overshooting. In such a view, we interconnect the axis aging and immune-hematopoietic system, which all convey important clues for the risk to develop malignancies.

A phase III, randomised, double-blind, multi-national clinical trial comparing SB12 (proposed eculizumab biosimilar) and reference eculizumab in patients with paroxysmal nocturnal haemoglobinuria

Treatment of paroxysmal nocturnal haemoglobinuria (PNH) includes the monoclonal antibody eculizumab. This randomised, double-blind, multi-national cross-over Phase III study in PNH patients aimed to demonstrate the equivalence of the proposed eculizumab biosimilar SB12 and reference eculizumab (Soliris, ECU). PNH patients with lactate dehydrogenase (LDH) ≥1·5× upper limit of normal were randomised into treatment sequences SB12-ECU or ECU-SB12. Four weekly infusions of 600 mg eculizumab were followed by fortnightly infusions of 900 mg until week 50 (ECU/SB12 cross-over at week 26). Primary endpoints were LDH at week 26 and the time-adjusted area under the effect curve (AUEC) of LDH over weeks 14‒26 and 40‒52. Among 46 patients (92%) who completed the study, the least squares mean (LSM) difference in LDH at week 26 (34·48; 95% confidence interval [CI] -47·66‒116·62 U/l) and geometric LSM ratio of time-adjusted AUEC of LDH (1·08; 90% CI 0·95‒1·23) were within pre-defined equivalence margins. Mean numbers of transfused red blood cell units, other secondary endpoints, pharmacokinetics, and pharmacodynamics were comparable. No patients developed anti-drug antibodies. Treatment-emergent adverse events were reported in 72% and 68% of patients in the SB12 and ECU treatment groups, respectively. The results demonstrate equivalence of SB12 to ECU and support SB12-use in PNH patients.

Biomarkers and laboratory assessments for monitoring the treatment of patients with paroxysmal nocturnal hemoglobinuria: Differences between terminal and proximal complement inhibition

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, life-threatening, acquired disease in which blood cells lacking complement regulatory proteins are destroyed because of uncontrolled complement activity. Since 2007, terminal complement inhibitors have revolutionized the treatment of this disease. However, patients treated with these inhibitors can still experience anemia because of C3-mediated extravascular hemolysis and clinically relevant levels of breakthrough or residual intravascular hemolysis. Proximal complement inhibitors, which are only just beginning to emerge, have the potential to address this problem by targeting components of the pathway upstream of C5, thereby protecting patients against both intra- and extravascular hemolysis. In this review, we describe different biomarkers that can be used to monitor complement pathway blockade and discuss key laboratory assessments for evaluating treatment efficacy. We also consider how these assessments are affected by each class of inhibitor and highlight how evolving treatment goals may influence the relative importance of these assessments.

Paroxysmal nocturnal hemoglobinuria: Where we stand

For the last 20 years, therapy of paroxysmal nocturnal hemoglobinuria (PNH) relied-up until recently-on antibody based terminal complement inhibitionon. PNH pathophysiology-a mutational defect leading to partial or complete absence of complement-regulatory proteins on blood cells-leads to intravascular hemolysis and consequences such as thrombosis and other sequelae. A plethora of new drugs interfering with the proximal and terminal complement cascade are under recent development and the first "proof-of-pinciple" proximal complement inhibitor targeting C3 has been approved in 2021. "PNH: where we stand" will try to give a brief account on where we came from and where we stand focusing on approved therapeutic options. The associated improvements as well as potential consequences of actual and future treatments as well as their impact on the disease will continue to necessitate academic and scientific focus on improving treatment options as well as on side effects and outcomes relevant to individual patient lives and circumstances in order to develop effective, safe, and available treatment for all hemolytic PNH patients globally.

With complements: C3 inhibition in the clinic

C3 is a key complement protein, located at the nexus of all complement activation pathways. Extracellular, tissue, cell-derived, and intracellular C3 plays critical roles in the immune response that is dysregulated in many diseases, making it an attractive therapeutic target. However, challenges such as very high concentration in blood, increased acute expression, and the elevated risk of infections have historically posed significant challenges in the development of C3-targeted therapeutics. This is further complicated because C3 activation fragments and their receptors trigger a complex network of downstream effects; therefore, a clear understanding of these is needed to provide context for a better understanding of the mechanism of action (MoA) of C3 inhibitors, such as pegcetacoplan. Because of C3's differential upstream position to C5 in the complement cascade, there are mechanistic differences between pegcetacoplan and eculizumab that determine their efficacy in patients with paroxysmal nocturnal hemoglobinuria. In this review, we compare the MoA of pegcetacoplan and eculizumab in paroxysmal nocturnal hemoglobinuria and discuss the complement-mediated disease that might be amenable to C3 inhibition. We further discuss the current state and outlook for C3-targeted therapeutics and provide our perspective on which diseases might be the next success stories in the C3 therapeutics journey.

Thromboembolic events in patients with paroxysmal nocturnal hemoglobinuria (PNH): Real world data of a Greek nationwide multicenter retrospective study

Thrombosis is the most common and a life-threatening complication in patients with Paroxysmal Nocturnal Hemoglobinuria. One-third of patients with PNH experience at least one thromboembolic event during the course of the disease, with thrombosis being the most common cause of death in these patients. The mechanism of thrombosis in PNH is complex and continues to be of great research interest. Since the introduction of C5 complement inhibitors in the treatment of PNH, the incidence of thromboembolic events has decreased substantially. We retrospectively analyzed data concerning the thrombotic episodes of 41 patients with PNH from 14 different national hematology centers in Greece. Sixteen patients (39%) experienced at least one episode of thrombosis, including, seven (43.8%) at diagnosis, seven (43.8%) during the course of the disease and two (12.5%) patients prior to PNH diagnosis. Nearly half of these individuals (n=7, 43.8%) had multiple episodes of thrombosis during the course of their disease. The most common sites of thrombosis were intra-abdominal veins. Three out of 26 patients developed thrombosis while on eculizumab. In none of the 16 patients, the thrombotic event was fatal. Our findings, despite the small number of patients, confirmed that thrombosis continues to be a significant complication of PNH affecting more than one third of the patients.

The burden of illness of patients with paroxysmal nocturnal haemoglobinuria receiving C5 inhibitors: clinical outcomes and medical encounters from the patient perspective

OBJECTIVES

To assess the clinical and healthcare resource burden among C5 inhibitor (C5i)-treated patients with paroxysmal nocturnal haemoglobinuria (PNH), using patient-reported data.

METHODS

This web-based, cross-sectional survey (01FEB2021-31MAR2021) of adults with PNH treated with eculizumab (France, Germany, UK) or ravulizumab (Germany) included: patient characteristics; treatment patterns/dosage; haematological outcomes (haemoglobin [Hb] levels, transfusions, thrombotic events, breakthrough haemolysis); and medical encounters. Treatment and Hb-level subgroup differences were assessed with statistical significance tests.

RESULTS

Among 71 patients, 98.6% were C5i-treated for ≥3 months. The majority (with reported Hb levels) had levels ≤12.0 g/dL (85.7%; n = 54/63). The mean Hb level was 10.2 g/dL (standard deviation [SD]: 2.0; median 10.0 g/dL). Treatment with above label-recommended doses was reported by 30.4% (eculizumab) and 5.3% (ravulizumab) of patients. Within the past 12 months among patients treated with C5i for ≥1 year: 24.1% had ≥1 transfusion; 3.2% had ≥1 thrombosis; and 28.6% had ≥1 breakthrough haemolysis. Among all patients, 26.8% and 31.0% reported emergency department/room [ER] and inpatient visits, respectively. Mean annual, per-patient all-cause medical encounters were: 0.5 (ER); 1.9 (inpatient); and overall outpatient visits ranged by setting from 2.0 to 6.4. Most encounters were PNH-related, with means of 0.4 (ER); 1.8 (inpatient); and 1.6-5.4 (outpatient). Primary haematological and medical encounter outcomes were similar between treatment as well as Hb-level subgroups, with almost no statistically significant differences.

CONCLUSIONS

Despite at least 3 months of C5i treatment, high proportions of patients with PNH reported low haemoglobin levels and required transfusions and hospitalizations, which suggests remaining unmet needs.

Subacute stent thrombosis with spontaneously resolved secondary thrombi in paroxysmal nocturnal hemoglobinuria: a case report

Background

Stent thrombosis (ST) is a serious complication; however, a method to prevent ST in patients with thrombophilic diseases has not been established.

Case presentation

We report a case of subacute ST in a patient with paroxysmal nocturnal hemoglobinuria (PNH) who was receiving continuous heparin treatment in addition to the usual dual antiplatelet therapy for contrast defects at the proximal site of the occluded right coronary artery and the proximal site of the left circumflex artery. Despite the resolution of thrombi in secondary lesions, subacute ST occurred. After percutaneous coronary intervention for ST, triple therapy, including oral anticoagulation for PNH-related thrombosis, was initiated. The patient subsequently underwent craniotomy hematoma removal for hemorrhagic cerebral infarction.

Conclusions

Reported cases of ST in patients with PNH are very few, and this case adds evidence with respect to antithrombotic therapy in patients with thrombotic tendencies. Both thrombosis and bleeding should be considered when administering antithrombotic therapy to patients with thrombotic diseases. If there are specific treatments for thrombophilic diseases, they should be initiated early.

Classical Paroxysmal Nocturnal Hemoglobinuria Presenting With Severe Anemia and Pigmented Acute Kidney Injury

Paroxysmal nocturnal hemoglobinuria is a rare form of intravascular hemolysis caused by an acquired deficiency of complement regulatory glycoproteins. In our case, a 53-year-old male presented with fatigue, discoloration of urine, and reduced urine output. Preliminary investigations showed severe anemia (3.7 g/dl) and hyperkalemia (7.6 mmol/L) in the setting of acute kidney injury, requiring urgent dialysis. Four units of packed cell volumes were transfused for the correction of anaemia. Following initial stabilization, flow cytometry and a fluorescein-labeled proaerolysin (FLAER) study showed a total deficiency of CD59 in 95.92% of granulocytes and a 97.14% deficiency in monocytes. A bone marrow biopsy showed erythroblast hyperplasia confirming the diagnosis of classical paroxysmal nocturnal hemoglobinuria. The patient was treated with steroids, androgens, and iron supplementation and made a complete recovery with a near-total resolution of his acute kidney injury. This paper aims to review the clinical features and investigations in order to focus on acute kidney injury as an outcome of paroxysmal nocturnal hemoglobinuria.

Portal vein thrombosis as the first presentation of paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired clonal hematopoietic stem cell disorder, characterized by hemolytic anemia, bone marrow failure and thrombosis. Portal vein thrombosis (PVT) is relatively rare in patients with PNH. In this paper, we reported PVT as the first clinical presentation of PNH in a female patient. PVT related symptoms resolved after anticoagulation therapy.

Low Rate of Clinically Evident Extravascular Hemolysis in Patients with Paroxysmal Nocturnal Hemoglobinuria Treated with a Complement C5 Inhibitor: Results from a Large, Multicenter, US Real-World Study

Purpose

Most patients with paroxysmal nocturnal hemoglobinuria (PNH) treated with a complement protein 5 (C5) inhibitor achieve full control of terminal complement activity and intravascular hemolysis. The minority remains anemic and transfusion dependent despite this control. Etiology for ongoing anemia is multifactorial and includes bone marrow failure, breakthrough hemolysis, extravascular hemolysis (EVH) and nutritional deficiencies.

Patients and Methods

To evaluate the potential etiologies of hemoglobin levels <10 g/dL despite receiving C5 inhibitor therapy, we performed a retrospective US chart review of adult patients with PNH and treated for at least 12 months with eculizumab (n=53), ravulizumab (n=32), or eculizumab followed by ravulizumab (n=15). Clinically evident EVH was defined as at least one transfusion, reticulocyte count ≥120×10⁹/L and hemoglobin level ≤9.5 g/dL. Safety data were not collected. Mean treatment duration was 26.5±17.2 months.

Results

Treatment with C5 inhibitors significantly improved hemoglobin, lactate dehydrogenase, and number of transfusions versus baseline. Among the patients with hemoglobin <10 g/dL during the last 6 months of treatment (n=38), one patient (eculizumab) had clinically evident EVH, and 10 patients had active concomitant bone marrow failure. Bone marrow failure was a major contributor to hemoglobin <10 g/dL and transfusion dependence; clinically evident EVH was uncommon.

Conclusion

A range of hematologic causes need to be considered when evaluating anemia in the presence of treatment with a C5 inhibitor.

The role of the alternative pathway in paroxysmal nocturnal hemoglobinuria and emerging treatments

INTRODUCTION

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by uncontrolled activation of the terminal complement pathway, leading to intravascular hemolysis (IVH) and a prothrombotic state. Treatment with terminal complement (C5) inhibitors, the current standard of care, suppresses IVH and reduces the risk of thrombosis and the associated morbidity and mortality. Opportunities exist to further improve care by alternative modes of administration and the reduction of clinically significant anemia and transfusion dependence caused by extravascular hemolysis in some patients.

AREAS COVERED

This review describes the pathophysiology of PNH, provides an overview of the current standard of care, and discusses potential avenues for enhancing patient care, with a focus on the literature describing new and emerging treatments that target the alternative pathway. Emerging treatments include biosimilars and novel C5 inhibitors as well as agents with novel mechanisms of action that target the proximal complement pathways (C3 inhibitors, factor B inhibitors, and factor D inhibitors).

EXPERT OPINION

Alternative complement pathway inhibitors may offer further benefit as long as terminal complement is completely inhibited to reduce IVH and disease activity. This may lead to improvements in adherence and health-related quality of life for patients with PNH.