Baseline characteristics and disease burden in patients in the International Paroxysmal Nocturnal Hemoglobinuria Registry

The burden of illness of patients with paroxysmal nocturnal haemoglobinuria receiving C5 inhibitors in France, Germany and the United Kingdom: Patient-reported insights on symptoms and quality of life

OBJECTIVES

To assess the clinical, humanistic and economic burden of paroxysmal nocturnal haemoglobinuria (PNH) among C5 inhibitor (C5i)-treated patients with PNH.

METHODS

This was a web-based, cross-sectional survey (01FEB2021-31MAR2021) of adults with PNH treated with eculizumab (France, Germany, United Kingdom) or ravulizumab (Germany). Self-reported outcomes included: patient characteristics; patient-reported symptoms; and standardised patient-reported outcomes (e.g. Functional Assessment of Chronic Illness Therapy [FACIT]-Fatigue, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 [EORTC QLQ-C30]).

RESULTS

Among 71 included patients, 98.6% were C5i-treated for ≥3 months (88.7% ≥12 months); among those with self-reported haemoglobin (Hb) levels (n = 63), most (85.7%) were anaemic (defined as ≤12.0 g/dL). Fatigue was the most common symptom at both diagnosis (73.2%) and survey time (63.4%); there were no statistically significant differences in symptom prevalence between treatment subgroups (eculizumab vs. ravulizumab). Total FACIT-Fatigue and EORTC QLQ-C30 scores were substantially lower than European general population references, but there were no statistically significant differences between treatment subgroups. Hb-level subgroups (<10.5 g/dL vs. ≥10.5 d/dL) followed similar trends for all measures, with few significant subgroup differences.

CONCLUSIONS

Results suggest that there remains a considerable burden and unmet need among C5i-treated patients with PNH that requires improved therapies.

Changes in hemoglobin and clinical outcomes drive improvements in fatigue, quality of life, and physical function in patients with paroxysmal nocturnal hemoglobinuria: post hoc analyses from the phase III PEGASUS study

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, chronic, acquired, hematologic, life-threatening disease characterized by thrombosis, impaired bone marrow function, and complement-mediated hemolysis. The PEGASUS phase III clinical trial demonstrated superiority of pegcetacoplan over eculizumab regarding improvements in hemoglobin levels in patients with suboptimal response to prior eculizumab treatment. The objective of this post hoc analysis was to compare the patient-reported outcome (PRO) response rates observed among PEGASUS participants and the relationships between their PRO scores with clinical and hematological parameters. Data from the 16-week randomized, controlled (1:1 to pegcetacoplan or eculizumab) period of the PEGASUS trial included comparisons of weekly PRO measurements taken using the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) scale and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core-30 (EORTC QLQ-C30) scales. A clinically meaningful FACIT-F response was defined as an increase from baseline of ≥5 points. Convergent validity was assessed using conventional threshold correlations between FACIT-F, EORTC QLQ-C30, and laboratory parameters. A clinically meaningful improvement in FACIT-F score was seen in 72.2% of pegcetacoplan-treated patients compared to 22.9% of eculizumab-treated patients. At week 16, the FACIT-F total score correlated with hemoglobin levels (r=0.47, p< 0.0001), absolute reticulocyte count (r=−0.37, p<0.01), and indirect bilirubin levels (r=−0.25, p<0.05). Clinically meaningful improvements in pegcetacoplan-treated patients were also observed for multiple EORTC scales. Fatigue and other self-reported outcomes were correlated with clinically meaningful improvements in clinical and hematological parameters. Clinical trial registration: NCT03500549

Inhibition of C3 with pegcetacoplan results in normalization of hemolysis markers in paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired hematologic disorder characterized by complement-mediated hemolysis. C5 inhibitors (eculizumab/ravulizumab) control intravascular hemolysis but do not prevent residual extravascular hemolysis. The newly approved complement inhibitor, pegcetacoplan, inhibits C3, upstream of C5, and has the potential to improve control of complement-mediated hemolysis. The PADDOCK and PALOMINO clinical trials assessed the safety and efficacy of pegcetacoplan in complement inhibitor-naïve adults (≥ 18 years) diagnosed with PNH. Patients in PADDOCK (phase 1b open-label, pilot trial) received daily subcutaneous pegcetacoplan (cohort 1: 180 mg up to day 28 [n = 3]; cohort 2: 270–360 mg up to day 365 [n = 20]). PALOMINO (phase 2a, open-label trial) used the same dosing protocol as PADDOCK cohort 2 (n = 4). Primary endpoints in both trials were mean change from baseline in hemoglobin, lactate dehydrogenase, haptoglobin, and the number and severity of treatment-emergent adverse events. Mean baseline hemoglobin levels were below the lower limit of normal in both trials (PADDOCK: 8.38 g/dL; PALOMINO: 7.73 g/dL; normal range: 11.90–18.00 g/dL), increased to within normal range by day 85, and were sustained through day 365 (PADDOCK: 12.14 g/dL; PALOMINO: 13.00 g/dL). In PADDOCK, 3 serious adverse events (SAE) led to study drug discontinuation, 1 of which was deemed likely related to pegcetacoplan and 1 SAE, not deemed related to study drug, led to death. No SAE led to discontinuation/death in PALOMINO. Pegcetacoplan was generally well tolerated and improved hematological parameters by controlling hemolysis, while also improving other clinical PNH indicators in both trials. These trials were registered at www.clinicaltrials.gov (NCT02588833 and NCT03593200).

Pegcetacoplan in paroxysmal nocturnal hemoglobinuria: A systematic review on efficacy and safety

Introduction

Pegcetacoplan, a pegylated penta-decapeptide, targets complement C3 to control both intravascular and extravascular hemolysis. This systematic review aims to study the efficacy and safety of pegcetacoplan in paroxysmal nocturnal hemoglobinuria (PNH).

Methods

We performed a comprehensive and systematic literature search for all studies on PubMed, Google Scholar, Cochrane Library, and clinicaltrials.gov. The studies were searched using keywords "paroxysmal nocturnal hemoglobinuria" or "PNH," "Pegcetacoplan" or "Empaveli." The primary outcomes included change in hemoglobin level, transfusion independence, absolute reticulocyte count, and lactate dehydrogenase (LDH) level after pegcetacoplan therapy. The safety outcomes included the proportion of deaths and adverse effects.

Results

We included a total of three studies. The total number of patients with PNH was112. 59.83% were female. In the PADDOCK study and study by Hillmen et al., the average increase in hemoglobin was 3.68 g/L and 2.37 g/L, respectively. In the study by de Castro et al., the hemoglobin level increased from below the lower limit of normal and stayed in the normal range (11.1-15.9 g/L). Absolute reticulocyte count and LDH levels decreased in all patients receiving pegcetacoplan. In the study by de Castro et al., LDH level remained stable, and within <1.5× upper limit of normal, whereas in the study by Hillman, the mean change of LDH from baseline was -15 ± 43 U/L. Two of six, seven of 23, and seven of 41 patients reported adverse events in the study by de Castro et al., PADDOCK, and Hillmen et al., respectively.

Conclusion

Pegcetacoplan effectively improves hemoglobin level and transfusion requirements in patients with PNH, including those unresponsive to eculizumab.

Clinicopathological Profile of Paroxysmal Nocturnal Hemoglobinuria among Omani Patients: A Case Series

We aimed to estimate the nature and prevalence of paroxysmal nocturnal hemoglobinuria (PNH) among Omani patients. We performed a retrospective review of all patients who were tested for PNH by flow cytometry at the Sultan Qaboos University Hospital, Muscat, between 2012 and 2019. Manifestations, treatment modalities, and outcomes were assessed. A total of 10 patients were diagnosed or were on follow-up for PNH (median age 22.5 years). Clinical manifestations included fatigue (80%) and anemia (70%). Six patients had classical PNH with hemolysis, three had PNH in the context of aplastic anemia, and one patient had subclinical PNH. The median total clone size (type II + III) for neutrophils was 95.5 (range: 1.5-97) (FLAER/CD24) and for monocytes was 91.6 (range = 0.04-99) (FLAER/CD14). Four patients had clone sizes > 50% at the time of diagnosis. The median follow-up period of the patients was 62 months (range = 8-204 months). One patient suffered thrombosis. Three patients were on immunosuppressant agents, five were initiated on eculizumab, and four had a bone marrow transplant. No deaths were reported in the cohort. The estimated average incidence of PNH among Omani patients was 1.5 per 5 000 000. PNH is rare in the Omani population. The predominant presentation is hemolytic anemia.

Pharmacokinetics and pharmacodynamics of pozelimab alone or in combination with cemdisiran in non-human primates

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disease caused by uncontrolled complement activation; effective and approved treatments include terminal complement inhibition. This study assessed whether combination cemdisiran (an investigational N-acetylgalactosamine-conjugated RNAi therapeutic that suppresses liver production of complement component C5) and pozelimab (an investigational fully human monoclonal antibody against C5) results in more effective and durable complement activity inhibition than the individual agents alone in non-human primates. Cynomolgus monkeys received a single subcutaneous injection of cemdisiran (5 or 25 mg/kg), pozelimab (5 or 10 mg/kg), or combination cemdisiran and pozelimab (5+5 mg/kg, 5+10 mg/kg, or 25+10 mg/kg, respectively). When given in combination, pozelimab was administered 2 weeks after cemdisiran dosing. Pharmacokinetics and ex vivo pharmacodynamic properties were assessed. The half-life of pozelimab alone was 12.9–13.3 days; this increased to 19.6–21.1 days for pozelimab administered in combination with cemdisiran. In ex vivo classical pathway hemolysis assays (CH₅₀), pozelimab + cemdisiran combinations achieved durable and more complete suppression of complement activity (8–13 weeks) vs monotherapy of either agent. Cemdisiran monotherapy demonstrated dose-dependent suppression of total C5 concentrations, with the higher dose (25 mg/kg) achieving >90% maximum suppression. Total C5 concentrations after administration of pozelimab + cemdisiran combinations were similar compared with administration of cemdisiran alone. The combination of pozelimab + cemdisiran mediates complement activity inhibition more efficiently than either pozelimab or cemdisiran administered alone. The pharmacokinetic/pharmacodynamic profile of combination pozelimab + cemdisiran in non-human primates appears suitable for further clinical investigation as a potential long-acting treatment for PNH and other complement-mediated diseases.

The importance of terminal complement inhibition in paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, chronic hematologic disorder associated with inappropriate terminal complement activity on blood cells that can result in intravascular hemolysis (IVH), thromboembolic events (TEs), and organ damage. Untreated individuals with PNH have an increased risk of morbidity and mortality. Patients with PNH experiencing IVH often present with an elevated lactate dehydrogenase (LDH; ⩾ 1.5 × the upper limit of normal) level which is associated with a significantly higher risk of TEs, one of the leading causes of death in PNH. LDH is therefore used as a biomarker for IVH in PNH. The main objective of PNH treatment should therefore be prevention of morbidity and mortality due to terminal complement activation, with the aim of improving patient outcomes. Approval of the first terminal complement inhibitor, eculizumab, greatly changed the treatment landscape of PNH by giving patients an effective therapy and demonstrated the critical role of terminal complement and the possibility of modulating it therapeutically. The current mainstays of treatment for PNH are the terminal complement component 5 (C5) inhibitors, eculizumab and ravulizumab, which have shown efficacy in controlling terminal complement-mediated IVH, reducing TEs and organ damage, and improving health-related quality of life in patients with PNH since their approval by the United States Food and Drug Administration in 2007 and 2018, respectively. Moreover, the use of eculizumab has been shown to reduce mortality due to PNH. More recently, interest has arisen in developing additional complement inhibitors with different modes of administration and therapeutics targeting other components of the complement cascade. This review focuses on the pathophysiology of clinical complications in PNH and explores why sustained inhibition of terminal complement activity through the use of complement inhibitors is essential for the management of patients with this chronic and debilitating disease.

Evaluating ravulizumab for the treatment of children and adolescents with paroxysmal nocturnal hemoglobinuria

INTRODUCTION

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired clonal stem cell disease harvesting a somatic mutation in the phosphatidylinositol glycan class A (PIG-A) gene. This mutation results in a deficiency in cell membrane complement regulators leading to activation of the terminal complement pathway, clinically presenting as hemolytic anemia and thrombosis, and frequently associated with bone marrow failure. This condition was historically managed with supportive care and bone marrow transplant.

AREAS COVERED

This paper will review primary data on the pharmacology, efficacy, and safety of ravulizumab in the pediatric/adolescent population gathered from literature search from PubMed, abstracts from annual meetings, and medication package inserts. Eligible clinical trials identified on the clinicaltrials.gov website are also briefly discussed.

EXPERT OPINION

: The discovery of eculizumab, a monoclonal antibody against complement protein 5, has revolutionized the PNH landscape, with decreased hemolysis and risk of thrombosis, improved quality-of-life, and has become the standard of care. Ravulizumab, a longer-acting C5-inhibitor with 4 times the half-life of eculizumab, was recently approved for pediatric patients with PNH. Ravulizumab is effective, safe, and has the potential to improve quality of life further. In addition, ongoing clinical trials using second-generation complement inhibitors may provide promising new interventions in PNH.

Composite endpoint to evaluate complement inhibition therapy in patients with paroxysmal nocturnal hemoglobinuria

This study developed and explored a novel composite endpoint to assess the overall impact that treatment can have on patients living with paroxysmal nocturnal hemoglobinuria (PNH). Candidate composite endpoint variables were selected by a group of experts and included: lactate dehydrogenase levels as a measure of intravascular hemolysis; complete terminal complement inhibition; absence of major adverse vascular events, including thrombosis; absence of any adverse events leading to death or discontinuation of study treatment; transfusion avoidance; and improvements in fatigue-related quality of life as determined by the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue score. From these variables, a novel composite endpoint was constructed and explored using data collected in the ravulizumab PNH Study 301 (NCT02946463). Thresholds were defined and reported for each candidate variable. Five of the six candidate variables were included in the final composite endpoint; the FACIT-Fatigue score was excluded. Composite endpoint criterion was defined as patients meeting all five selected individual component thresholds. All patients in the ravulizumab arm achieved complete terminal complement inhibition and a reduction in lactate dehydrogenase levels; 51.2% and 41.3% of patients in the ravulizumab arm and eculizumab arm, respectively, achieved all composite endpoint component thresholds (treatment difference: 9.4%; 95% confidence interval: -3.0, 21.5). The composite endpoint provided a single and simultaneous measurement of overall benefit for patients receiving treatment for PNH. Use of the composite endpoint in future PNH research is recommended to determine clinical benefit, and its use in health technology assessments should be evaluated.

Literature Review of Fatigue Scales and Association with Clinically Meaningful Improvements in Outcomes Among Patients With and Without Paroxysmal Nocturnal Hemoglobinuria

Introduction

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare blood disorder characterized by anemia and debilitating fatigue. Limited evidence characterizes the association between hemoglobin, an indicator of anemia and disease activity, and patient-reported fatigue scales. This review identifies benchmarks for clinically meaningful improvements in patients with and without PNH.

Methods

MEDLINE, Embase, Cochrane, and PsycINFO databases were searched along with Google Scholar to identify publications for patients with and without PNH. Full-text articles and conference abstracts of clinical trials or observational studies that examined patient-reported fatigue or associations between fatigue and hemoglobin were included.

Results

Fourteen publications were included in this study. Four clinical trials conducted in patients with PNH reported that patients achieved and sustained clinically meaningful improvements in fatigue. However, these studies did not examine the association between fatigue and hemoglobin. Ten studies conducted in patients with cancer and anemia (with or without chemotherapy) demonstrated an association between increased hemoglobin and improvements in fatigue (P < 0.05). The greatest incremental gain in fatigue improvement was observed when hemoglobin increased from 11 to 12 g/dL.

Conclusion

Evidence among patients with cancer without PNH demonstrates that increased hemoglobin levels are associated with clinically significant improvements in fatigue. Future studies should validate this relationship among patients with PNH.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02111-7.

Effect of eculizumab treatment in patients with paroxysmal nocturnal hemoglobinuria with or without high disease activity: Real-world findings from the International Paroxysmal Nocturnal Hemoglobinuria Registry

BACKGROUND

The effects of eculizumab treatment in paroxysmal nocturnal hemoglobinuria (PNH) patients with or without high-disease activity (HDA), defined by LDH ≥ 1.5 × ULN and history of major adverse vascular events (MAVEs; including thrombotic events [TEs]); anemia; and/or physician-reported abdominal pain, dyspnea, dysphagia, erectile dysfunction, fatigue, and/or hemoglobinuria, in the International PNH Registry were evaluated.

METHODS

Registry patients were stratified by baseline HDA and eculizumab-treatment status. Longitudinal changes in laboratory and clinical PNH-related endpoints were evaluated using linear mixed models (continuous variables) or Poisson regression (incidence rates).

RESULTS

As of May 1, 2017, 3009 patients (HDA/eculizumab-treated, n = 913; HDA/never-treated, n = 651; no-HDA/eculizumab-treated, n = 173; no-HDA/never-treated, n = 1272) were analyzed. Higher proportions of eculizumab-treated patients had HDA and history of MAVEs. In patients with and without HDA, respectively, eculizumab treatment resulted in reductions from baseline for (1) LDH ratio (mean [SD]: -5.3 [4.0] and -2.3 [3.8]); (2) incidence rate ratio (IRR) for MAVEs (-80% and -70%); (3) IRR for TEs (-80% for both); and (4) units of red blood cell transfusions per year (from 6.8 to 2.8 and 3.6 to 2.5 units).

CONCLUSIONS

Eculizumab treatment in a real-world setting improved outcomes, including substantial decreases in hemolysis, MAVE rates, TEs, and transfusions in PNH patients regardless of HDA.

The burden of illness in patients with paroxysmal nocturnal hemoglobinuria receiving treatment with the C5-inhibitors eculizumab or ravulizumab: results from a US patient survey

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare and life-threatening disease with symptoms of hemolysis and thrombosis. Current therapies for this complement-mediated disease rely predominantly on inhibition of the C5 complement protein. However, data on treatment responses and quality of life in C5-inhibitor (C5i)-treated PNH patients are scarce. The objective of this study was to determine C5i treatment effects on clinical parameters, PNH symptoms, quality of life, and resource use for PNH patients. This cross-sectional study surveyed 122 individuals in the USA receiving treatment for PNH with C5-targeted monoclonal antibodies, eculizumab (ECU) or ravulizumab (RAV). Despite most patients receiving C5i therapy for ≥ 3 months (ECU 100%, n = 35; RAV 95.4%, n = 83), many patients remained anemic with hemoglobin levels ≤ 12 g/dL in 87.5% (n = 28/32) and 82.9% (n = 68/82) of ECU and RAV recipients, respectively. A majority of patients on ECU (88.6%; n = 31/35) and RAV (74.7%; n = 65/87) reported fatigue symptoms. Among PNH patients receiving C5i therapy for ≥ 12 months, some still reported thrombotic events (ECU, 10.0%, n = 1/10; RAV, 23.5%, n = 4/17) and required transfusions within the past year (ECU, 52.2%, n = 12/23; RAV, 22.6%, n = 7/31). Other patient-reported PNH symptoms included breakthrough hemolysis, shortness of breath, and headaches. Patients reported scores below the average population norms on the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) scales. Overall, this study found that PNH patients receiving ECU or RAV therapy demonstrated a significant burden of illness, highlighting the need for improved PNH therapies.

Association of Blood Group Antigen CD59 with Disease

In 2014, the membrane-bound protein CD59 became a blood group antigen. CD59 has been known for decades as an inhibitor of the complement system, located on erythrocytes and on many other cell types. In paroxysmal nocturnal haemoglobinuria (PNH), a stem cell clone with acquired deficiency to express GPI-anchored molecules, including the complement inhibitor CD59, causes severe and life-threatening disease. The lack of CD59, which is the only membrane-bound inhibitor of the membrane attack complex, contributes a major part of the intravascular haemolysis observed in PNH patients. This crucial effect of CD59 in PNH disease prompted studies to investigate its role in other diseases. In this review, the role of CD59 in inflammation, rheumatic disease, and age-related macular degeneration is investigated. Further, the pivotal role of CD59 in PNH and congenital CD59 deficiency is reviewed.

The Role of T Lymphocytes in the Pathogenesis of Paroxysmal Nocturnal Hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematopoietic stem cell genetic mutation disease that causes defective erythrocyte membrane hemolysis. Its pathologic basis is the mutation of the PIG-A gene, whose product is necessary for the synthesis of glycosylphosphatidylinositol (GPI) anchors; the mutation of PIG-A gene results in the reduction or deletion of the GPI anchor, which leads to the deficiency of GPI-anchored proteins (GPI-APs), such as CD55 and CD59, which are complement inhibitors. The deficiency of complement inhibitors causes chronic complement-mediated intravascular hemolysis of GPI-anchor-deficient erythrocyte. PIG-A gene mutation could also be found in bone marrow hematopoietic stem cells (HSCs) of healthy people, but they have no growth advantage; only the HSCs with PIG-A gene mutation in PNH patients have this advantage and expand. Besides, HSCs from PIG-A-knockout mice do not show clonal expansion in bone marrow, so PIG-A mutation cannot explain the clonal advantage of the PNH clone and some additional factors are needed; thus, in recent years, many scholars have put forward the theories of the second hit, and immune escape theory is one of them. In this paper, we focus on how T lymphocytes are involved in immune escape hypothesis in the pathogenesis of PNH.

SUZ12 participates in the proliferation of PNH clones by regulating histone H3K27me3 levels

Paroxysmal nocturnal hemoglobinuria (PNH) is a disease involving hematopoietic stem cell membrane defects caused by acquired phosphatidylinositol glycan anchor biosynthesis class A (PIGA) mutations. In this study, 97 target genes were selected as a target gene panel and screened in 23 PNH patients via the sequencing of specific DNA target regions. Through functional analysis, we identified that suppressor-of-Zeste 12 (SUZ12) may be involved in the proliferation of PNH clones. mRNA and protein expression levels of SUZ12 and the trimethylation level of histone H3 at lysine 27 (H3K27) in CD59^- peripheral blood leukocytes from PNH patients were higher than those in CD59⁺ cells from PNH patients and peripheral blood leukocytes from healthy controls. In addition, the relative expression of SUZ12 in PNH patients was positively correlated with Ret% and the proportion of PNH clones. When we knocked down SUZ12 expression in a PIGA knockdown THP-1 cell line (THP-1 KD cells), the trimethylation of histone H3K27(H3K27me3) and cell proliferation decreased, apoptosis increased, and cell cycle arrest occurred in G0/G1 phase. In conclusion, SUZ12 participates in the proliferation of PNH clones by regulating histone H3K27me3 levels. Our results may provide new therapeutic targets and possibilities for PNH patients.

Indirect and Direct Mapping of the Cancer-Specific EORTC QLQ-C30 onto EQ-5D-5L Utility Scores

OBJECTIVE

The aim of this study was to develop a response mapping algorithm to predict EQ-5D-5L utilities from European Organisation for Research and Treatment Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) scores and compare performance with direct mapping approaches to identify the best performing algorithm.

METHODS

The Multi-Instrument Comparison dataset contains responses to both the EQ-5D-5L and QLQ-C30 questionnaires from 692 individuals with a broad range of cancers. Response mapping was conducted, fitting ordered logistic regressions to predict response levels for each of the five EQ-5D dimensions and utilities were predicted using the US and Japanese EQ-5D-5L value sets to test the algorithm performance. Various direct mapping models were fitted: ordinary least squares, tobit, two-part (TPM), adjusted limited dependent variable mixture and beta mixture models. Model assessment and recommendations regarding the best mapping algorithm was based on goodness-of-fit statistics, predictive ability (measures of error, distribution of predicted utilities) and in sample cross-validation.

RESULTS

The response mapping model performed well in terms of predictive ability and measurement error using the US or Japanese value set, with mean absolute error ranging from 0.0708 to 0.0988, and comparably to the TPM, which was the best performing direct algorithm.

CONCLUSION

The developed mapping algorithms enable the prediction of EQ-5D-5L utilities from QLQ-C30 scores when EQ-5D-5L data have not been directly collected in clinical trials. The response mapping model offers the possibility of predicting EQ-5D-5L utility values using any national value set and can be generalised to multiple countries and oncology settings.

[Brain infarction and cerebral venous thrombosis in paroxysmal nocturnal hemoglobinuria: case report]

A 65-year-old woman with a six-year history of paroxysmal nocturnal hemoglobinuria (PNH) was admitted due to weakness in the right leg following a seven-day history of fever and upper respiratory infection. MRI revealed several high-intensity areas in bilateral frontal lobe cortices and the left cerebellum on diffusion-weighted imaging, and signal hypointensity along the course of the cortical vein in the left frontal lobe on T₂*-weighted imaging. We diagnosed cerebral venous thrombosis and brain infarction, and commenced heparin infusion. She developed right-sided dens hemiparesis on hospital day 6, when brain CT showed subcortical hemorrhage in the left frontal lobe. Despite eculizumab administration and decompressive craniectomy for hematoma, she died on hospital day 26. Thrombosis in PNH has been recognized as a life-threating complication, and intensive treatment including emergent administration of eculizumab is warranted if this situation arises.

When does a PNH clone have clinical significance?

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired blood disease caused by somatic mutations in the phosphatidylinositol glycan class A (PIGA) gene required to produce glycophosphatidyl inositol (GPI) anchors. Although PNH cells are readily identified by flow cytometry due to their deficiency of GPI-anchored proteins, the assessment of the clinical significance of a PNH clone is more nuanced. The interpretation of results requires an understanding of PNH pathogenesis and its relationship to immune-mediated bone marrow failure. Only about one-third of patients with PNH clones have classical PNH disease with overt hemolysis, its associated symptoms, and the highly prothrombotic state characteristic of PNH. Patients with classical PNH benefit the most from complement inhibitors. In contrast, two-thirds of PNH clones occur in patients whose clinical presentation is that of bone marrow failure with few, if any, PNH-related symptoms. The clinical presentations are closely associated with PNH clone size. Although exceptions occur, bone marrow failure patients usually have smaller, subclinical PNH clones. This review addresses the common scenarios that arise in evaluating the clinical significance of PNH clones and provides practical guidelines for approaching a patient with a positive PNH result.

Phase 2 study of danicopan in patients with paroxysmal nocturnal hemoglobinuria with an inadequate response to eculizumab

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by uncontrolled terminal complement activation and subsequent intravascular hemolysis (IVH). C5 inhibitors prevent membrane attack complex formation, but patients may experience extravascular hemolysis (EVH) and continue to require blood transfusions. Danicopan, an oral proximal complement inhibitor of alternative pathway factor D (FD), is designed to control IVH and EVH. In a phase 2 dose-finding trial, eculizumab-treated transfusion-dependent patients with PNH (n = 12) received danicopan, 100 to 200 mg thrice daily, in addition to their eculizumab regimen for 24 weeks. End points included hemoglobin (Hgb) change vs baseline at week 24 (primary), reduction in blood transfusions, and patient-reported outcomes. Safety, tolerability, and pharmacokinetics/pharmacodynamics were measured. Twelve patients received ≥1 danicopan dose; 1 patients discontinued from a serious adverse event deemed unlikely related to danicopan. Eleven patients completed the 24-week treatment period. Addition of danicopan resulted in a mean Hgb increase of 2.4 g/dL at week 24. In the 24 weeks prior to danicopan, 10 patients received 31 transfusions (50 units) compared with 1 transfusion (2 units) in 1 patient during the 24-week treatment period. Mean Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue score increased by 11 points from baseline to week 24. The most common adverse events were headache, cough, and nasopharyngitis. Addition of danicopan, a first-in-class FD inhibitor, led to a meaningful improvement in Hgb and reduced transfusion requirements in patients with PNH who were transfusion-dependent on eculizumab. These benefits were associated with improvement of FACIT-Fatigue. This trial was registered at www.clinicaltrials.gov as #NCT03472885.

Comparative effectiveness of pegcetacoplan versus ravulizumab in patients with paroxysmal nocturnal hemoglobinuria previously treated with eculizumab: a matching-adjusted indirect comparison

OBJECTIVE

In the absence of a head-to-head study, we assessed the comparative effectiveness of pegcetacoplan, a targeted C3 complement inhibitor, vs. ravulizumab, a C5 complement inhibitor, among patients with paroxysmal nocturnal hemoglobinuria (PNH) previously treated with eculizumab using matching-adjusted indirect comparison methodology.

METHODS

Individual patient data from the PEGASUS study (NCT03500549) comparing pegcetacoplan and eculizumab enabled adjustment for baseline differences compared with published results from the ALXN1210-PNH-302 study (NCT03056040), comparing ravulizumab and eculizumab. Adjusted differences and 95% confidence intervals (CIs) were computed via weighted Wald tests for comparisons of pegcetacoplan vs. ravulizumab, anchored to the common comparator eculizumab.

RESULTS

Sixty-eight patients from PEGASUS (36 pegcetacoplan; 32 eculizumab) and 195 from ALXN1210-PNH-302 (97 ravulizumab; 98 eculizumab) were included. Compared with ravulizumab, treatment with pegcetacoplan was associated with more transfusion avoidance (adjusted difference [95% CI] = +71.4% [53.5%, 89.3%]), hemoglobin level stabilization (+75.5% [56.4%, 94.6%]), lactate dehydrogenase (LDH) level normalization (+64.0% [41.8%, 86.1%]), and fewer blood transfusions (-5.7 units [-7.2, -4.2]). Additionally, patients who received pegcetacoplan experienced clinically meaningful improvements in fatigue (+8.2 points [3.8, 12.6]), global health status (+9.6 points [0.1, 19.0]), physical functioning (+11.5 points [3.6, 19.5]), and fatigue symptoms (-13.3 points [-23.7, -3.0]), compared with ravulizumab. Mean change from baseline in LDH level was not significantly different for pegcetacoplan vs. ravulizumab.

CONCLUSIONS

Results suggest that among patients previously treated with eculizumab, clinical, hematological, and quality of life endpoints were better for patients who received the C3 complement inhibitor pegcetacoplan vs. patients who received ravulizumab, a C5 complement inhibitor.

No impact of Asian ethnicity on EORTC QLQ-C30 scores: Group differences and differential item functioning in paroxysmal nocturnal hemoglobinuria

BACKGROUND

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, life-threatening terminal-complement-mediated disease resulting in intravascular hemolysis and thrombosis with significant morbidity and premature mortality. There exists no disease-specific quality-of-life (QOL) measure for PNH. Its QOL effects resemble those of hematologic cancers, which supports the use of cancer-specific QOL measures in PNH clinical trials. The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 has published norms for many European and North American countries, but not for Asian countries. We investigated differences by Asian ethnicity in scores and item function on the EORTC QLQ-C30.

METHODS

This secondary analysis focused on two non-inferiority PNH trials (301 and 302) comparing eculizumab and ravulizumab (n = 441). Analysis of covariance examined the main effect of Asian ethnicity on baseline EORTC QLQ-C30 scores, after adjusting for propensity scores encompassing trial, demographic and clinical factors. Mixed modeling of longitudinal data compared subscale scores in Asian vs. non-Asian patients, after propensity adjustment. Differential item function (DIF) was examined using ordinal regression models at baseline and longitudinally, to predict item score from total score, ethnicity, and their interaction to test for uniform DIF (significant main effect for Asian) and non-uniform DIF (significant Asian-by-total-score interaction).

RESULTS

Of the 15 baseline domains, Asian patients scored slightly better on role and emotional functioning and slightly worse on constipation and diarrhea (0.22 < Cohen's d < 0.36). In longitudinal models, Asians reported slightly higher appetite loss, diarrhea, and financial difficulties than non-Asians (R2 increment < 0.0005). There was negligible uniform and non-uniform DIF, i.e., R2 0 to 0.018, far below Zumbo's (1999) criterion of 0.13. On average there were larger differences from norms for Asians (mean = 0.05, sd = 0.44) than non-Asians (mean = -0.07, sd = 0.36), but the size and direction of the differences varied considerably by domain, age, and gender.

CONCLUSION

When compared to norms, Asian patients showed no systematic biases. DIF results supported this finding. We conclude that Asian ethnicity does not impact interpretation of EORTC QLQ-C30 scores.

A novel patient-reported outcome instrument assessing the symptoms of paroxysmal nocturnal hemoglobinuria, the PNH-SQ

BACKGROUND

Patient-reported outcome measures (PROs) used to measure symptoms of patients with paroxysmal nocturnal hemoglobinuria (PNH) in trials do not measure PNH symptoms comprehensively and do not assess daily fluctuations in symptoms. Following a literature review and consultation with a PNH expert, we drafted the PNH Symptom Questionnaire (PNH-SQ) and a patient-centric conceptual model of PNH symptoms and impacts. We then interviewed 15 patients with PNH to assess comprehensiveness of symptom capture from the patient perspective and to cognitively debrief the PNH-SQ. Patient interview data were also used to finalize the PNH conceptual model.

RESULTS

Participants mentioned 27 signs or symptoms of PNH spontaneously or after being probed; 93% reported experiencing ≥ 1 PNH symptom. Concept saturation was reached for all PNH symptoms. Further, interviews confirmed the instrument captured the most common PNH symptoms, including fatigue (87%), abdominal pain (60%), and difficulty swallowing (47%), with fatigue ranked as the most bothersome symptom. The interviews demonstrated that participants understood the items of the PNH-SQ (90-100%); considered the symptoms relevant (> 50- > 90%); the recall period appropriate (> 80-100%); and the response options suitable (> 80-100%). Participants also suggested changes regarding item redundancy and relevance; this feedback was used to finalize the instrument.

CONCLUSIONS

The finalized PNH-SQ assesses the presence and severity of 10 symptoms-abdominal pain, chest discomfort, difficulty sleeping, difficulty swallowing, difficulty thinking clearly, fatigue, headache, muscle weakness, pain in the legs or back, and shortness of breath-over 24 h. The PNH-SQ is a content-valid questionnaire suitable for assessing daily symptom presence and severity in PNH clinical trials.

Norm-based comparison of the quality-of-life impact of ravulizumab and eculizumab in paroxysmal nocturnal hemoglobinuria

Aims

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare and life-threatening intravascular hematologic disorder with significant morbidity and premature mortality. Clinical trials (NCT02946463 and NCT03056040) comparing ravulizumab with eculizumab for PNH have supported the non-inferiority of the former and similar safety and tolerability. This secondary analysis compared PNH trial participants after 26 weeks on either treatment (n = 438) to a general-population sample (GenPop) (n = 15,386) and investigated response-shift effects.

Methods

Multivariate analysis of covariance (MANCOVA) investigated function and symptom scores on the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 of people with PNH as compared to GenPop, after covariate adjustment. Risk-factor groups were created based on clinical indicators known to be associated with worse PNH outcomes, and separate MANCOVAs were computed for lower- and higher-risk-factor groups. Differential item functioning (DIF) analyses examined whether item response varied systematically (1) by treatment, (2) compared to GenPop, and (3) over time, the latter two suggesting and reflecting response-shift effects, respectively. DIF analyses examined 24 items from scales with at least two items. Recalibration response shift was operationalized as uniform DIF over time, reflecting the idea that, for a given group, the difficulty of endorsing an item changes over time, after adjusting for the total subscale score. Reprioritization response shift was operationalized as non-uniform DIF over time, i.e., the relative difficulty of endorsing an item over time changes across the total domain score.

Results

Across PNH risk-factor levels, people who had been on either treatment for 26 weeks reported better-than-expected functioning and lower symptom burden compared to GenPop. Ravulizumab generally showed larger effect sizes. Results were similar for lower and higher PNH risk factors, with slightly stronger effects in the former. DIF analyses revealed no treatment DIF, but did uncover group DIF (9 items with uniform DIF, and 11 with non-uniform) and DIF over time (7 items with uniform DIF, and 3 with non-uniform).

Conclusions

This study revealed that people with PNH on ravulizumab or eculizumab for 26 weeks reported QOL levels better than those of the general population. Significant effects of DIF by group and DIF over time support recalibration and reprioritization response-shift effects. These findings suggest that the treatments enabled adaptive changes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02016-8.

Complement and the prothrombotic state

In 2007 and 2009 the regulatory approval of the first-in-class complement inhibitor Eculizumab has revolutionized the clinical management of two rare, life-threatening clinical conditions: paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS). While being completely distinct diseases affecting blood cells and the glomerulus, PNH and aHUS remarkably share several features in their etiology and clinical presentation. An imbalance between complement activation and regulation at host surfaces underlies both diseases precipitating in severe thrombotic events that are largely resistant to anti-coagulant and/or anti-platelet therapies. Inhibition of the common terminal complement pathway by Eculizumab prevents the frequently occurring thrombotic events responsible for the high mortality and morbidity observed in patients not treated with anti-complement therapy. While many in vitro and ex vivo studies elaborate numerous different molecular interactions between complement activation products and hemostasis, this review focuses on the clinical evidence that links these two fields in humans. Several non-infectious conditions with known complement involvement are scrutinized for common patterns concerning a prothrombotic statues and the occurrence of certain complement activation levels. Next to PNH and aHUS, germline encoded CD59 or CD55 deficiency (the latter causing the disease Complement Hyperactivation, Angiopathic thrombosis, and Protein-Losing Enteropathy; CHAPLE), autoimmune hemolytic anemia (AIHA), (catastrophic) anti-phospholipid syndrome (APS, CAPS) and C3 glomerulopathy are considered. Parallels and distinct features among these conditions are discussed against the background of thrombosis, complement activation, and potential complement diagnostic and therapeutic avenues.

Real-World Healthcare Resource Utilization (HRU) and Costs of Patients with Paroxysmal Nocturnal Hemoglobinuria (PNH) Receiving Eculizumab in a US Population

INTRODUCTION

To evaluate the economic burden and treatment patterns of patients with paroxysmal nocturnal hemoglobinuria (PNH) treated with eculizumab, a C5 inhibitor, who were defined as blood transfusion-dependent (TD) versus blood transfusion-free (TF) in the US population.

METHODS

Patients aged at least 12 years with at least two claims for eculizumab infusion (first claim was the index date) were identified from the IBM® MarketScan® Research Databases (April 1, 2014-September 30, 2019). The overall PNH eculizumab user cohort was stratified into the TD cohort (i.e., at least one claim for blood transfusion within 6 months following any eculizumab infusion, including on the infusion date) or the TF cohort (i.e., all non-TD patients). Treatment patterns, healthcare resource utilization (HRU), and costs were evaluated and compared during follow-up (i.e., index date to end of enrollment or data availability).

RESULTS

Of 151 patients in the overall cohort (mean age 36.7 years; 55.6% female), 55 were TD (mean age 35.1 years; 67.3% female) and 96 were TF (mean age 37.6 years; 49.0% female). A total of 61% of patients (TD, 66%; TF, 58%) discontinued eculizumab, with TD patients having a shorter median time to discontinuation (TD, 0.5 years; TF, 0.9 years). TD patients had more all-cause hospitalizations than TF patients (p < 0.05). TD patients incurred higher all-cause direct medical costs (adjusted cost difference = $247,848) and medical-related absenteeism costs (adjusted cost difference = $4186) than TF patients (all p < 0.05), largely driven by hospitalizations. Similar trends were observed for PNH-related HRU and costs.

CONCLUSIONS

The economic burden of patients with PNH treated with eculizumab is greater among those dependent on blood transfusions.

Heme Burden and Ensuing Mechanisms That Protect the Kidney: Insights from Bench and Bedside

With iron at its core, the tetrapyrrole heme ring is a cardinal prosthetic group made up of many proteins that participate in a wide array of cellular functions and metabolism. Once released, due to its pro-oxidant properties, free heme in sufficient amounts can result in injurious effects to the kidney and other organs. Heme oxygenase-1 (HO-1) has evolved to promptly attend to such injurious potential by facilitating degradation of heme into equimolar amounts of carbon monoxide, iron, and biliverdin. HO-1 induction is a beneficial response to tissue injury in diverse animal models of diseases, including those that affect the kidney. These protective attributes are mainly due to: (i) prompt degradation of heme leading to restraining potential hazardous effects of free heme, and (ii) generation of byproducts that along with induction of ferritin have proven beneficial in a number of pathological conditions. This review will focus on describing clinical aspects of some of the conditions with the unifying end-result of increased heme burden and will discuss the molecular mechanisms that ensue to protect the kidneys.

Cost-Utility Analysis of Eculizumab for the Treatment of Paroxysmal Nocturnal Hemoglobinuria from the Perspective of the Brazilian Public Health System

OBJECTIVE

To perform a first cost-utility analysis of eculizumab for the treatment of paroxysmal nocturnal hemoglobinuria from the perspective of the Brazilian Unified Health System.

METHODS

A Markov decision model was developed for 35-year-old patients with symptomatic paroxysmal nocturnal hemoglobinuria. We used a cycle length of one month and a time horizon of 20 years. The effectiveness measure was the quality-adjusted life year (QALY). Data were extracted from clinical trials, historical cohorts, and Unified Health System databases. Resource use and costs were estimated from the perspective of the Unified Health System. Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

The estimated gain in effectiveness with the use of eculizumab was 1.08 QALY through the incremental cost of R$10,959,375.95. The incremental cost-effectiveness ratio was R$10,139,542.84 per QALY, being 331.92 times greater than the Brazilian gross domestic product per capita. In the deterministic sensitivity analysis, the parameters related to the utilities of health states were associated with greater impact in the model. The results of the probabilistic sensitivity analysis with 1000 simulations evidence that 100% of the simulations were not considered cost-effective with the arbitrated willingness to pay R$30,548.40 and R$91,645.20 per QALY.

CONCLUSIONS

The gain in effectiveness with the use of eculizumab was modest, associated with an unjustifiable incremental cost. Therefore, eculizumab is not a cost-effective drug compared with the current standard of care in the treatment of paroxysmal nocturnal hemoglobinuria from the Brazilian Unified Health System perspective.

Concept confirmation of the Treatment Administration Satisfaction Questionnaire (TASQ) in rare paroxysmal nocturnal hemoglobinuria

Background

This study was conducted to evaluate content validity of the IntraVenous and SubCutaneous Treatment Administration Satisfaction Questionnaires (TASQ-IV and TASQ-SC), for use in a clinical trial population of participants with paroxysmal nocturnal hemoglobinuria (PNH) undergoing eculizumab treatment.

Methods

Participants underwent semi-structured combined brief introduction to disease history and full cognitive debriefing interviews to establish symptoms and key impacts of PNH and to explore the clarity and relevance of both sets of instructions (TASQ-IV and TASQ-SC). The clarity, relevance, response options, and recall period of the TASQ-IV items were also explored.

Results

Ten participants with PNH were recruited. Fatigue was the most commonly reported symptom (n = 7); the most commonly reported impact of PNH was on physical activity (n = 4). Nine participants indicated understanding and relevance of the TASQ-IV instructions; three participants suggested changes. Of the 20 TASQ-IV items, ≥ 15 were considered understandable, relevant and to have suitable response options (n ≥ 8). The TASQ-SC instructions were understood by all participants; seven participants indicated relevance. While a few participants suggested minor changes for the items, these reflected the one-off completion of the measure in an interview setting and were thus not considered sufficient to justify modification of the measure for clinical trial completion.

Conclusions

Most participants understood the TASQ-IV and TASQ-SC instructions (n = 9 and 10, respectively) and the TASQ-IV items were considered clear, relevant and to have suitable response options, demonstrating face and content validity of the instruments for the clinical trial setting.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41687-021-00319-9.

Evaluation of clinical characteristics of patients with paroxysmal nocturnal hemoglobinuria treated with eculizumab in Turkey: a multicenter retrospective analysis

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare X-linked genetic disorder. On the contrary to its name, it is a multisystemic disease and various symptoms other than hemoglobinuria could be occurred. It could be life threatening especially because of thromboembolic events. In the last decade, a terminal complement inhibition with eculizumab approved with promising results for PNH patients. We conducted this study to evaluate the long term experience of eculizumab therapy from Turkey for the first time. Our cohort included 138 patients with PNH treated with eculizumab between January 2008 and December 2018 at 28 centers in Turkey. Laboratory and clinical findings at the time of diagnosis and after eculizumab therapy were recorded retrospectively. The median age was 39 (range 18-84) years and median granulocyte PNH clone size was 74% (range 3.06-99.84%) at the time of diagnosis. PNH with bone marrow failure syndrome was detected in 49 patients and the rest of 89 patients had classical PNH. Overall 45 patients (32.6%) had a history of any prior thrombotic event before eculizumab therapy and only 2 thrombotic events were reported during the study period. Most common symptoms are fatigue (75.3%), hemoglobinuria (18.1%), abdominal pain (15.2%) and dysphagia (7.9%). Although PNH is commonly related with coombs negativity, we detected coombs positivity in 2.17% of patients. Seven months after the therapy, increased hemoglobin level was seen and remarkably improvement of lactate dehydrogenase level during the treatment was occurred. In addition to previous studies, our real life data support that eculizumab is well tolerated with no serious adverse events and improves the PNH related findings.

Clinical characteristics and therapeutic outcomes of paroxysmal nocturnal hemoglobinuria patients in Turkey: a multicenter experience

The aim of this study is to collect paroxysmal nocturnal hemoglobinuria (PNH) patient data from hematology centers all over Turkey in order to identify clinical features and management of PNH patients. Patients with PNH were evaluated by a retrospective review of medical records from 19 different institutions around Turkey. Patient demographics, medical history, laboratory findings, and PNH-specific information, including symptoms at the diagnosis, complications, erythrocyte, and granulocyte clone size, treatment, and causes of death were recorded. Sixty patients (28 males, 32 females) were identified. The median age was 33 (range; 17-77) years. Forty-six patients were diagnosed as classic PNH and 14 as secondary PNH. Fatigue and abdominal pain were the most frequent presenting symptoms. After eculizumab became available in Turkey, most of the patients (n = 31/46, 67.4%) were switched to eculizumab. Three patients with classic PNH underwent stem cell transplantation. The median survival time was 42 (range; 7-183 months) months. This study is the first and most comprehensive review of PNH cases in Turkey. It provided us useful information to find out the differences between our patients and literature, which may help us understand the disease.

Markers of Thrombin Generation and Inflammation in Patients with Paroxysmal Nocturnal Hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) presents with intravascular hemolysis, bone marrow failure and thrombosis. Various studies have reported geographic and ethnic variation in prevalence of thrombosis in PNH. There is limited data on thrombosis in PNH from the Indian subcontinent. In this study we describe disease burden and risk factors for thrombosis in 18 Indian PNH patients. We studied markers of thrombin generation (Thrombin-antithrombin complexes; TAT and D-Dimer), endothelium and platelet activation (soluble P-selectin) and inflammation (interleukin-6; IL-6) in PNH patients and compared their levels with healthy controls. Thrombosis was identified in 17% of PNH patients. TAT, sP-selectin and D-Dimer levels were significantly elevated in PNH patients (TAT: 5.06 ± 1.08 ng/ml; sP-selectin: 80.57 ± 19.5 ng/ml; D-Dimer mean: 936 ng/ml 95% CI 559, 1310) compared to control population (TAT: 3.39 ± 0.769 ng/ml P = 0.016; sP-selectin: 44.67 ± 5.17 ng/ml P = 0.002). Using Youden's J statistic, the cut-off values for TAT and sP-selectin in our cohort of PNH patients were 2.90 ng/ml and 58.41 ng/ml respectively. TAT, sP-selectin and D-Dimer levels were elevated beyond the cut-off values in PNH patients with thrombosis compared to those without thrombosis. A positive correlation was noted between TAT, sP-selectin and D-Dimer levels. Increased TAT, sP-selectin, and D-Dimer levels may indicate impending thrombosis in PNH.

Thrombotic Complications in Patients with Immune-Mediated Hemolysis

Autoimmune hemolytic anemias are rare and heterogeneous disorders characterized by hemolysis, which is a well-recognized risk factor for thrombosis. The most common immune-mediated anemias are represented by autoimmune hemolytic anemia and paroxysmal nocturnal hemoglobinuria, both associated with a high rate of thrombosis. Multiple pathophysiological mechanisms for thrombosis have been proposed, involving hemolysis itself and additional effects of the immune system. Despite the increasing awareness of the thrombotic risk in these conditions, evidence-based guidance on prevention and management of thrombotic events is lacking. We herein report available evidence on epidemiological data on thrombosis and thrombophilia in immune-mediated hemolysis, together with possible underlying pathophysiological mechanisms. In addition, we summarize current recommendations for treatment of thrombosis in immune-mediated hemolysis. In particular, we address the issue of thrombotic complications treatment and prophylaxis by proposing a therapeutic algorithm, focusing on specific situations such as splenectomy and pregnancy.

One-year outcomes from a phase 3 randomized trial of ravulizumab in adults with paroxysmal nocturnal hemoglobinuria who received prior eculizumab

Ravulizumab every 8 weeks showed non‐inferiority to eculizumab every 2 weeks in a 26‐week, phase 3, randomized controlled trial in adults with paroxysmal nocturnal hemoglobinuria (PNH) who were clinically stable on eculizumab (NCT03056040). We report results from the first 26 weeks of the extension period in which patients continued ravulizumab (n = 96) or switched from eculizumab to ravulizumab (n = 95). At week 52, mean (SD) lactate dehydrogenase levels increased 8.8% (29%) with ravulizumab‐ravulizumab and 5.8% (27%) with eculizumab‐ravulizumab from primary evaluation period baseline. During the extension period, four patients (ravulizumab‐ravulizumab, n = 3; eculizumab‐ravulizumab, n = 1) experienced breakthrough hemolysis, but none associated with serum free C5 ≥ 0.5 μg/mL. Mean Functional Assessment of Chronic Illness Therapy (FACIT)‐Fatigue scores remained stable through week 52. During the extension period, proportions of patients avoiding transfusion remained stable (ravulizumab‐ravulizumab, 86.5%; eculizumab‐ravulizumab, 83.2%); 81.2% and 81.1%, respectively, had stabilized hemoglobin. All patients maintained serum free C5 levels < 0.5 μg/mL. Adverse events were generally similar between groups, and rates were lower in the extension period. Adults with PNH on stable eculizumab therapy who received ravulizumab over 52 weeks experienced durable efficacy, with consistent efficacy in patients who received eculizumab during the primary evaluation period and then switched to ravulizumab. Ravulizumab was well tolerated.

Frequency and perturbations of various peripheral blood cell populations before and after eculizumab treatment in paroxysmal nocturnal hemoglobinuria

While red blood cells (RBCs) and granulocytes have been more studied, platelets and reticulocytes are not commonly used in paroxysmal nocturnal hemoglobinuria (PNH) flow-cytometry and less is known about susceptibility to complement-mediated destruction and effects of anti-complement therapy on these populations. We performed flow-cytometry of RBCs and granulocytes in 90 PNH patients and of platelets and reticulocytes in a subgroup (N = 36), to unveil perturbations of these populations during PNH disease course before and after anti-complement treatment. We found that platelets and reticulocytes were less sensitive to complement-mediated lysis than RBCs but not as resistant as granulocytes, as shown by mean sensitive fraction (difference in a given PNH population vs. PNH granulocyte clone size). In treated patients, reticulocytes, platelets, RBCs (with differences between type II and III) and granulocytes significantly increased post-treatment, confirming the role of PNH hematopoiesis within the context of anti-complement therapy. Moreover, we found that PNH platelet clone size reflects PNH granulocyte clone size. Finally, we established correlations between sensitive fraction of PNH cell-types and thrombosis. In sum, we applied a flow-cytometry panel for investigation of PNH peripheral blood populations' perturbations before and after eculizumab treatment to explore complement-sensitivity and kinetics of these cells during the disease course.

Safety of current treatments for paroxysmal nocturnal hemoglobinuria

Introduction: Eculizumab, which is indicated to treat patients with paroxysmal nocturnal hemoglobinuria (PNH), is proven to decrease intravascular hemolysis and thrombosis and improve survival. Ravulizumab is a long-acting, second-generation complement component 5 (C5) inhibitor designed to alleviate the burden of the eculizumab treatment schedule and reduce the frequency of breakthrough hemolysis. As the clinical benefits of these treatments have been emphasized, their safety also should be considered. Areas covered: This article reviews safety data for the current approved PNH treatments from published articles about eculizumab and ravulizumab in patients with PNH. Special settings (pregnancy, pediatrics, long-term safety of continued eculizumab treatment, and extravascular hemolysis) are also discussed. Expert opinion: In phase 3 trials, eculizumab and ravulizumab were found to be safe and well tolerated. In addition, 10 years of experience with eculizumab provided evidence that mitigates initial concerns about infectious events. However, to minimize meningococcal infections, vaccination and close monitoring remain essential. Because extravascular hemolysis limits eculizumab efficacy in some patients, continued investigation of proximal complement inhibitors is warranted to obviate this mechanism. Long-term safety data for ravulizumab treatment are needed.

Paroxysmal nocturnal hemoglobinuria: patient journey and burden of disease

Patients with paroxysmal nocturnal hemoglobinuria (PNH) often experience a lengthy path to diagnosis. Fewer than 40% of patients with PNH receive a diagnosis within 12 months of symptom onset, and 24% of all PNH diagnoses can take 5 years or longer. Diagnostic delay is a source of distress and can affect emotional well-being for patients with PNH. In PNH disease management, patients and care providers focus on risk of organ failure and mortality related to disease progression; nonetheless, patients' health-related quality of life (HRQOL) is largely affected by extensive treatment requirements and nonfatal complications of disease, such as fatigue. In particular, thrombosis is associated with significant impairments in physical and social functioning and global health status and significant fatigue. Among patients with anemia who are transfusion dependent, the burden of transfusion is considerable. Transfusion dependence has a negative effect on HRQOL; is associated with risks and complications, including iron overload; and results in lost productivity due to travel times to and time spent at infusion centers. DISCLOSURES: This research was developed under a research contract between RTI Health Solutions and Apellis Pharmaceuticals and was funded by Apellis Pharmaceuticals. Bektas, Copley-Merriman, and Khan are employees of RTI Health Solutions. Sarda is an employee of Apellis Pharmaceuticals. Shammo consults for Apellis Pharmaceuticals.

Paroxysmal nocturnal hemoglobinuria: current treatments and unmet needs

The current standard of care for paroxysmal nocturnal hemoglobinuria (PNH) are the C5 inhibitors eculizumab and ravulizumab, both monoclonal antibodies designed to target the complement protein C5, thereby preventing its cleavage and the formation of the terminal attack complex. C5 inhibitors have yielded substantial improvements in the treatment of PNH and changed the mortality and morbidity, as well as health-related quality of life of patients with the disease. These treatments target underlying intravascular hemolysis; however, they do not address extravascular hemolysis, resulting in incomplete response and remaining symptoms in some patients. Therefore, despite treatment with a C5 inhibitor, some patients still experience anemia with associated fatigue, transfusion needs, and impaired health-related quality of life. DISCLOSURES: This research was developed under a research contract between RTI Health Solutions and Apellis Pharmaceuticals and was funded by Apellis Pharmaceuticals. Bektas, Copley-Merriman, and Khan are employees of RTI Health Solutions. Sarda is an employee of Apellis Pharmaceuticals. Shammo consults for Apellis Pharmaceuticals.

C3 inhibition with pegcetacoplan in subjects with paroxysmal nocturnal hemoglobinuria treated with eculizumab

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired, life-threatening hematologic disease characterized by chronic complement-mediated hemolysis and thrombosis. Despite treatment with eculizumab, a C5 inhibitor, 72% of individuals remain anemic. Pegcetacoplan (APL-2), a PEGylated C3 inhibitor, has the potential to provide more complete hemolysis control in patients with PNH. This open-label, phase Ib study was designed to assess the safety, tolerability, and pharmacokinetics of pegcetacoplan in subjects with PNH who remained anemic during treatment with eculizumab. Pharmacodynamic endpoints were also assessed as an exploratory objective of this study. Data are presented for six subjects in cohort 4 who received treatment for up to 2 years. In total, 427 treatment-emergent adverse events (TEAEs) were reported, 68 of which were possibly related to the study drug. Eight serious TEAEs occurred in two subjects; three of these events were considered possibly related to the study drug. Pegcetacoplan pharmacokinetic concentrations accumulated with repeated dosing, and steady state was reached at approximately 6-8 weeks. Lactate dehydrogenase levels were well controlled by eculizumab at baseline. Pegcetacoplan increased hemoglobin levels and decreased both reticulocyte count and total bilirubin in all six subjects. Improvements were observed in Functional Assessment of Chronic Illness Therapy Fatigue scores. Two subjects discontinued for reasons unrelated to pegcetacoplan. All four subjects who completed the study transitioned to pegcetacoplan monotherapy following eculizumab discontinuation and avoided transfusions. In this small study, pegcetacoplan therapy was generally well-tolerated, and resulted in an improved hematological response by achieving broad hemolysis control, enabling eculizumab discontinuation.

One-year efficacy and safety of ravulizumab in adults with paroxysmal nocturnal hemoglobinuria naïve to complement inhibitor therapy: open-label extension of a randomized study

BACKGROUND

Ravulizumab, the only long-acting complement C5 inhibitor for adults with paroxysmal nocturnal hemoglobinuria (PNH), demonstrated non-inferiority to eculizumab after 26 weeks of treatment in complement inhibitor-naïve patients during a phase III randomized controlled trial. We present open-label extension results with up to 52 weeks of treatment.

METHODS

Patients assigned to ravulizumab every 8 weeks (q8w) or eculizumab every 2 weeks during the randomized primary evaluation period received ravulizumab q8w during the 26-week extension. Efficacy endpoints were lactate dehydrogenase (LDH) normalization, transfusion avoidance, breakthrough hemolysis (BTH), LDH levels, Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale, and stabilized hemoglobin. Serum free C5 levels and safety were assessed. Outcomes as of the data cut-off (4 September 2018) were summarized using descriptive statistics.

RESULTS

Overall, 124 patients continued ravulizumab, and 119 switched from eculizumab to ravulizumab. During the extension, 43.5% and 40.3% of patients in the ravulizumab-ravulizumab and eculizumab-ravulizumab arms, respectively, achieved LDH normalization; 76.6% and 67.2% avoided transfusion. BTH decreased in the eculizumab-ravulizumab arm; no events were associated with free C5 ⩾0.5 μg/mL while receiving ravulizumab. Overall, 73.4% and 65.5% of patients in the ravulizumab-ravulizumab and eculizumab-ravulizumab arms, respectively, achieved stabilized hemoglobin. Similar proportions of patients achieved ⩾3-point improvement in FACIT-Fatigue at week 52 (ravulizumab-ravulizumab, 64.5%; eculizumab-ravulizumab, 57.1%). All patients maintained free C5 <0.5 μg/mL during the ravulizumab extension, including those who experienced C5 excursions ⩾0.5 μg/mL while receiving eculizumab during the primary evaluation period. Adverse events were comparable between groups and decreased over time.

CONCLUSION

In adult, complement inhibitor-naïve patients with PNH, ravulizumab q8w for up to 52 weeks demonstrated durable efficacy and was well tolerated, with complete and sustained free C5 inhibition and a decreased incidence of BTH with no events associated with loss of free C5 control.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02946463.

[Thrombocytopenia and thromboses in a young woman]

This article reports the case of a 34-year-old female patient with multiple thrombotic events (cerebral venous sinus thrombosis, ischemic duodenitis) with simultaneous thrombocytopenia (ca. 70/nl). A paroxysmal nocturnal hemoglobinuria without detectable hemolysis and with simultaneous myelodysplastic syndrome was causative for these symptoms. This rare disease is important to consider in the differential diagnosis of chronic inflammatory rheumatic diseases, such as systemic lupus erythematosus, antiphospholipid antibody syndrome and vasculitis.

Development of a patient-reported outcome questionnaire for aplastic anemia and paroxysmal nocturnal hemoglobinuria (PRO-AA/PNH)

BACKGROUND

The introduction of new therapy modalities has significantly improved the outcome of aplastic anemia (AA) and paroxysmal nocturnal hemoglobinuria (PNH) patients. However, relatively little is known about the exact disease burden of AA/PNH since standardized assessments of symptoms including health-related quality of life (HRQoL) are frequently missing or inadequately designed for this rare patient group. We aimed to develop AA/PNH-specific questionnaires for self-reporting of symptoms, which could be included in electronic platforms for data collection and patient care.

METHODS

By scoping review, we extracted any reported symptoms in AA/PNH and their prevalence from the literature (Phase I). Consensus rounds with patients and medical experts were conducted to identify core symptoms reported in the literature and to add missing items (Phase II). Ultimately, AA/PNH-specific patient-reported outcome (PRO) questionnaires including the selected measures were designed (Phase III).

RESULTS

AA symptoms from 62 and PNH symptoms from 45 observational studies were extracted from the literature. Twenty-four patients and seven medical experts identified 11 core symptoms including HRQoL issues after three consensus rounds. Significant differences in the symptom ranking of patients versus medical experts could be observed. Therefore, patient- as well as expert-centered PRO questionnaires in AA and PNH were created following the concepts of validated instruments.

CONCLUSION

The development of symptom self-reporting questionnaires for AA and PNH was feasible and the disease-specific PRO questionnaires can now be validated within a web-based workflow in a subsequent feasibility study.

The Inhibition of Complement System in Formal and Emerging Indications: Results from Parallel One-Stage Pairwise and Network Meta-Analyses of Clinical Trials and Real-Life Data Studies

This manuscript presents quantitative findings on the actual effectiveness of terminal complement component 5 (C5) inhibitors and complement component 1 (C1) esterase inhibitors through their formal and common “off-label” (compassionate) indications. The results emanated from pairwise and network meta-analyses to present evidence until September 2019. Clinical trials (CT) and real-life non-randomized studies of the effects of interventions (NRSI) are consistent on the benefits of C5 inhibitors and of the absence of effects of C1 esterase inhibitors (n = 7484): Mathematically, eculizumab (surface under the cumulative ranking area (SUCRA) >0.6) and ravulizumab (SUCRA ≥ 0.7) were similar in terms of their protective effect on hemolysis in paroxysmal nocturnal hemoglobinuria (PNH), thrombotic microangiopathy (TMA) in atypical hemolytic uremic syndrome (aHUS), and acute kidney injury (AKI) in aHUS, in comparison to pre-/off-treatment state and/or placebo (SUCRA < 0.01), and eculizumab was efficacious on thrombotic events in PNH (odds ratio (OR)/95% confidence interval (95% CI) in CT and real-life NRSI, 0.07/0.03 to 0.19, 0.24/0.17 to 0.33) and chronic kidney disease (CKD) occurrence/progression in PNH (0.31/0.10 to 0.97, 0.66/0.44 to 0.98). In addition, meta-analysis on clinical trials shows that eculizumab mitigates a refractory generalized myasthenia gravis (rgMG) crisis (0.29/0.13 to 0.61) and prevents new acute antibody-mediated rejection (AMR) episodes in kidney transplant recipients (0.25/0.13 to 0.49). The update of findings from this meta-analysis will be useful to promote a better use of complement inhibitors, and to achieve personalization of treatments with this class of drugs.

Prognostic factors and follow-up parameters in patients with paroxysmal nocturnal hemoglobinuria (PNH): experience of the Austrian PNH network

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematologic disease characterized by a deregulated complement system, chronic Coombs-negative, intravascular hemolysis, and a variable clinical course with substantial risk to develop thromboembolic events. We analyzed diagnostic and prognostic parameters as well as clinical endpoints in 59 adult patients suffering from PNH in 5 hematology centers in Austria (observation period: 1978-2015). Median follow-up time was 5.6 years. The median clone size at diagnosis amounted to 55% and was higher in patients with classical PNH (81%) compared to patients with PNH associated with aplastic anemia (AA) or myelodysplastic syndromes (MDS) (50%). The clone size also correlated with lactate dehydrogenase (LDH) levels. In one patient, anemia improved spontaneously and disappeared with complete normalization of LDH after 16 years. Seventeen patients received therapy with eculizumab. The rate of thromboembolic events was higher in the pre-eculizumab era compared with eculizumab-treated patients but did not correlate with the presence of age-related clonal hematopoiesis or any other clinical or laboratory parameters. Peripheral blood colony-forming progenitor cell counts were lower in PNH patients compared with healthy controls. Only two patients with classical PNH developed MDS. Overall, 7/59 patients died after 0.5-32 years. Causes of death were acute pulmonary hypertension, Budd-Chiari syndrome, and septicemia. Overall survival (OS) was mainly influenced by age and was similar to OS measured in an age-matched healthy Austrian control cohort. Together, compared with previous times, the clinical course and OS in PNH are favorable, which may be due to better diagnosis, early recognition, and eculizumab therapy.

Healthcare resource utilization among commercially insured patients with cold agglutinin disease in the United States

Aims: Cold agglutinin disease (CAD) is a rare subtype of autoimmune hemolytic anemia associated with increased thromboembolism risk and early mortality. Healthcare resource utilization (HRU) in CAD has not been reported. We aimed to compare HRU of patients with CAD with a matched non-CAD cohort in the United States.Materials and methods: Patients with CAD were identified from 2006 to 2016 in the Optum-Humedica database using CAD terms in clinical notes and hematologist review. Patients were required to have Integrated Delivery Network records and ≥6 months' follow-up before and after the first CAD mention date (index date). Patients with CAD were matched to a non-CAD cohort based on demographics. Multivariate analyses assessed inpatient hospitalizations, outpatient visits, emergency room visits, and transfusion use between cohorts 6 months before and 12 months after the index date.Results: Of 814 patients with CAD, 410 met inclusion criteria and were matched to 3,390 patients without CAD. Mean age of patients with CAD was 68.0 years; approximately 62% were female. In the 12 months after the index date, mean inpatient hospitalizations (0.83 vs. 0.25), outpatient visits (17.26 vs. 6.77), emergency room visits (0.55 vs. 0.32), and transfusion days (1.05 vs. 0.05) were higher for patients with CAD than the matched non-CAD cohort (all p < .0001). Similarly, in the 6 months before the index date, patients with CAD had higher HRU than matched patients without CAD for all measures evaluated.Limitations: Results of this study are based on patient information from the Optum-Humedica database, which is limited to commercially insured patients and may not represent the overall CAD population.Conclusions: CAD places a substantial burden on patients and healthcare systems. In addition, the high HRU for patients with CAD observed in the 6 months before diagnosis indicates that disease awareness and better diagnostic practices may be needed.

Beneficial effects of eculizumab regardless of prior transfusions or bone marrow disease: Results of the International Paroxysmal Nocturnal Hemoglobinuria Registry

OBJECTIVES

To evaluate the effects of eculizumab on transfusions and thrombotic events (TEs) in patients with and without prior history of transfusion in the International Paroxysmal Nocturnal Hemoglobinuria (PNH) Registry.

METHODS

Registry patients enrolled on or before January 1, 2018, initiated on eculizumab no more than 12 months prior to enrollment, having known transfusion status for the 12 months before eculizumab initiation, and ≥12 months of Registry follow-up after eculizumab initiation, were included.

RESULTS

Eculizumab treatment was associated with a 50% reduction in transfusions in patients with a transfusion history (10.6 units/patient-year before eculizumab vs 5.4 after; P < .0001), with greater reduction observed in those with no history of bone marrow disease vs those with bone marrow disease. Mean lactate dehydrogenase levels decreased from a mean of 6.7 to 1.4 times the upper limit of normal (ULN) in patients with transfusion history and from 5.1 to 1.2 times ULN in those with no transfusion history. TE and major adverse vascular event rates also decreased by 70% in patients with and without history of transfusion.

CONCLUSIONS

The benefit of eculizumab therapy does not appear to be limited to any group defined by transfusion history or bone marrow disease history.

A Rare Case of Paroxysmal Nocturnal Hemoglobinuria With Bilateral Renal Vein Thrombosis

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematopoietic stem cell (HSC) disorder characterized by a partial or complete deficiency of glycosyl-phosphatidylinositol (GPI)-linked membrane proteins, which leads to intravascular hemolysis. The loss of CD55 and CD59, two GPI-anchored proteins on red blood cell surfaces, from mutations in the X-linked phosphatidylinositol glycan class A (PIGA) gene, causes unrestricted proliferation of complement activation. The loss of CD59 especially leads to ‘paroxysms’ of acute intravascular hemolysis during events of stress. Extravascular hemolysis also occurs without CD55 as the accumulation of C3 on red blood cell surfaces leads to their destruction by the reticuloendothelial system. Diagnosis of PNH relies primarily on clinical presentation and flow cytometry assays used to detect the GPI-anchored proteins, CD55 and CD59; however, fluorescein‐labeled proaerolysin variant (FLAER) is seen to have a significant advantage over CD55 and CD59. Typical symptoms of the disorder include fatigue, shortness of breath, hemoglobinuria, abdominal pain and bone marrow failure. Thrombosis also occurs secondary to nitric oxide (NO) deficiency, release of procoagulants, increased tissue factor and reduced fibrinolysis. The classification of PNH is subdivided into three types: classical, PNH with another bone marrow disorder and subclinical PNH. Management of hemolysis, thrombosis and pancytopenia is based on the pathogenesis involved. Inhibition of complement in the form of humanized monoclonal antibody against complement C5 (eculizumab) is seen as an emerging treatment option, while stem cell/bone marrow transplant may also be offered. We present a rare case of PNH with bilateral renal vein thrombosis, who was diagnosed with classical PNH on clinical presentation and flow cytometry. He was initially offered bone marrow transplantation but was lost to follow-up and later presented with bilateral renal vein thrombosis. He was managed conservatively with transfusions and anticoagulation, and was discharged for follow-up on an outpatient basis.