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

Abstract 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)

Clinically Important Difference for the FACIT-Fatigue Scale in Paroxysmal Nocturnal Hemoglobinuria: A Derivation from International PNH Registry Patient Data

Abstract Background: Fatigue is a common symptom associated with paroxysmal nocturnal hemoglobinuria (PNH). Eculizumab, a C5 inhibitor approved for treatment of PNH, has been shown to significantly alleviate fatigue, as indicated by reduced scores on the Functional Assessment of Chronic Illness Therapy-Fatigue scale (FACIT-Fatigue). FACIT-Fatigue scores range from 0-52 (higher scores indicate less fatigue); this assessment is validated for use in patients with PNH and has been used extensively both in clinical trials and in the International PNH Registry. In patients with cancer, the FACIT-Fatigue clinically important difference (CID) is estimated to be improvement of 3-5 points. This CID is commonly applied in PNH studies; however, no disease-specific CID for FACIT-Fatigue has been estimated in patients with PNH. A PNH-specific CID would be informative in evaluating changes in fatigue impact and could serve as a more robust criterion for evaluating treatment efficacy. The objective of this analysis was to determine the FACIT-Fatigue CID for patients with PNH using distribution- and anchor-based approaches and real-world data from the International PNH Registry. Methods: Adults with PNH who initiated eculizumab within 28 days of enrollment in the PNH Registry as of January 2021 with non-missing baseline FACIT-Fatigue scores were included in the analysis. FACIT-Fatigue scores were assessed at baseline and 6, 12, 24, and 36 months. Two distribution-based CID estimates were calculated using: 1) 0.5 × SD and 2) standard error of measurement (SEM). The SEM was calculated as SD−sqrt(1-α), where α represents the internal consistency measurement Cronbach's alpha. Cronbach's alpha was calculated from the 13 FACIT-Fatigue subscales. Anchor-based estimates considered 2 continuous patient-reported outcome variables: 1) European Organization for Research and Treatment of Cancer (EORTC) Global Health Status Quality of Life (QoL) summary score (quartiles; higher scores indicate better quality of life), and 2) EORTC Global Health Status Fatigue Subscale score (quartiles; lower scores indicate less fatigue). The baseline FACIT-Fatigue score was calculated for each predefined categorization of the anchors; the mean of differences in FACIT-Fatigue between adjacent categories was calculated and referenced as the anchor-based CID. Changes in anchors and high disease activity (HDA) shift from baseline to each follow-up visit were then assessed by FACIT-Fatigue score change (≤1 CID, no change, or ≥1 CID). HDA was defined as lactate dehydrogenase ratio ≥1.5 × upper limit of normal and ≥1 of the following: history of a major adverse vascular event (including a thrombotic event); anemia; or physician-reported abdominal pain, dyspnea, dysphagia, fatigue, hemoglobinuria, or erectile dysfunction. Results: 423 patients were included in the analysis (Table). The majority of patients were white or of Caucasian descent (84%); 3% were of Hispanic or Latino ethnicity. At baseline, 93% of patients had physician documentation of fatigue in their medical history (mean FACIT-Fatigue score, 29.4). The 2 distribution-based CIDs were 7 using 0.5 × SD and 5 using SEM; internal consistency was high (α=0.87). For anchor-based measurements, the CID was 8 using the EORTC QoL score and 10 using the EORTC fatigue subscale score. The percentage of patients who changed from having HDA at baseline to no HDA at eculizumab-treated follow-up visits increased over time. Using the SEM as the referent CID (owing to the high α value), the majority of these patients experienced &amp;gt;1 CID in FACIT-Fatigue that was sustained through 36 months (Figure). Results were similar when 0.5 × SD was used. Conclusion: Collectively, these results support the use of 5 points as the CID for FACIT-Fatigue in individual patients with PNH, which, although not necessarily the minimal value, is close to the range of CIDs reported in other diseases (3-5 points). This finding, obtained from a real-world dataset with a large number of patients, helps establish an important metric for assessment of the meaningful treatment response of patients with PNH. Of note, this CID is markedly smaller than the group average FACIT-Fatigue improvement of 10 points achieved with long-term eculizumab treatment in the pivotal blinded Phase 3 TRIUMPH study. Figure 1 Figure 1. Disclosures Cella: FACIT: Membership on an entity's Board of Directors or advisory committees. Ueda: Sanofi: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Chugai Pharmaceutical: Consultancy, Honoraria, Research Funding; Alexion Pharma: Consultancy, Honoraria. Tomazos: Alexion, AstraZeneca Rare Disease: Current Employment. Gustovic: Alexion, AstraZeneca Rare Disease: Current Employment. Wang: Alexion, AstraZeneca Rare Disease: Current Employment. Patel: Alexion, AstraZeneca Rare Disease: Current Employment. Schrezenmeier: Novartis: Honoraria; Alexion, AstraZeneca Rare Disease: Honoraria, Other: Travel support, Research Funding; Roche: Honoraria; Apellis: Honoraria; Sanofi: Honoraria. </jats:sec

Long-Term Survival Benefit of Eculizumab Treatment in Patients with Paroxysmal Nocturnal Hemoglobinuria: Data from the International PNH Registry

Abstract Background Eculizumab, the first C5 inhibitor approved for paroxysmal nocturnal hemoglobinuria (PNH), transformed PNH treatment by improving survival to that of an age- and sex- matched general population. Previous analyses demonstrating the survival benefit of eculizumab in patients with PNH leveraged historical data and were limited by small patient numbers and short follow-up durations; few evaluated survival of patients receiving eculizumab compared with untreated patients. The objective of the current analysis was to describe the baseline characteristics and overall survival of a large international cohort of eculizumab-treated patients compared with a contemporaneous untreated cohort using data from the prospective, observational International PNH Registry (NCT01374360). Methods Data from patients enrolled in the Registry after March 16, 2007 with complete information for birth date, sex, enrollment date, and treatment status were included (database cut-off, April 12, 2021). Ever-treated patients were those who received eculizumab for a minimum treatment period of 35 days while enrolled in the Registry; never-treated patients did not receive eculizumab at any time before or during Registry participation. Univariate and multivariate analyses were performed using a Cox proportional hazards that incorporated the following parameters at baseline as covariates: treatment status, presence of high disease activity (HDA), age, sex, history of bone marrow failure (BMF), history of thrombotic events (TE), transfusion dependence, and estimated glomerular filtration rate ≤60 mL/min/1.73 m 2. HDA was defined as lactate dehydrogenase (LDH) ratio ≥1.5 × upper limit of normal (ULN) and ≥1 of the following: history of major adverse vascular events (including TE); anemia (hemoglobin &amp;lt;10 g/dL), or physician-documented abdominal pain, dyspnea, dysphagia, fatigue, hemoglobinuria, or erectile dysfunction at any time before and including baseline. Baseline was defined as the date of eculizumab treatment initiation (ever-treated patients) or date of Registry enrollment (never-treated patients). Survival time was analyzed using a left-truncation approach that mapped time in patients' survival based on disease start date, defined as the earliest date of first-reported PNH diagnosis, PNH symptom, or first consistent flow cytometry result. Results Baseline characteristics of the 4627 patients included in the analysis (mean [SD] age at disease start, 40.2 [18.71] years; 53% female; 75% white) were comparable between the ever-treated and never-treated groups (n=1892 and n=2735, respectively). Compared with never-treated patients, more ever-treated patients had LDH ≥1.5 × ULN (90% vs 35%), and fewer had &amp;lt;10% PNH granulocytes (3% vs 57%) or history of BMF (45% vs 76%). The univariate Cox proportional hazard ratio (HR) for mortality in ever-treated vs never-treated patients was 0.48 (95% CI, 0.39-0.60; P&amp;lt;0.0001), indicating a 52% increase in survival in the treated group (Table). Among ever-treated patients, those with HDA at baseline experienced the largest reduction in mortality risk (HR [95% CI], 0.46 [0.33-0.64]; n=174); however, decreased mortality was also evident in ever-treated patients without HDA (HR, 0.65 [0.39-1.10]; n=212) or with unknown HDA status (HR, 0.50 [0.32-0.76; n=120) at baseline. Overall survival probability by treatment status was consistently greater in ever-treated vs never-treated patients through 20 years of follow-up; survival probability at 20 years was 82% (ever-treated) vs 69% (never-treated). Although long-term survival probability was greatest throughout follow-up in ever-treated patients with HDA at baseline, increased survival among ever-treated patients was evident in all 3 HDA status groups (Figure). Conclusion In this analysis of Registry data, treatment with the C5 inhibitor eculizumab improved patient survival compared with a never-treated cohort at a comparable time point in their disease course. Covariates were assessed at baseline only and competing risks and time on treatment were not controlled for, which are potential limitations. Survival benefits conferred by eculizumab treatment were observed regardless of HDA status at baseline, were more pronounced in treated patients with HDA vs those without HDA, and were maintained through 2 decades of real-world follow-up. Figure 1 Figure 1. Disclosures Terriou: Alexion, AstraZeneca Rare Disease: Consultancy, Membership on an entity's Board of Directors or advisory committees. Patriquin: Alexion, AstraZeneca Rare Disease: Consultancy, Honoraria, Speakers Bureau; Biocryst: Honoraria; Apellis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria. Griffin: Alexion, AstraZeneca Rare Disease: Honoraria, Membership on an entity's Board of Directors or advisory committees; BioCryst Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sobi Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Apellis: Other: Educational grant support. Lee: Alexion, AstraZeneca Rare Disease: Honoraria, Membership on an entity's Board of Directors or advisory committees. Gustovic: Alexion, AstraZeneca Rare Disease: Current Employment. Patel: Alexion, AstraZeneca Rare Disease: Current Employment. Szer: Alexion, AstraZeneca Rare Disease: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Apellis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Prevail Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. </jats:sec

Efficacy of Eculizumab in Pediatric Patients with Paroxysmal Nocturnal Hemoglobinuria in the International PNH Registry

Abstract Background/Objective: Paroxysmal nocturnal hemoglobinuria (PNH) is an extremely rare disease and is even more rare in children; pediatric cases are estimated to account for &lt;5% of all PNH cases (Ware RE, et al. N Engl J Med. 1991;325:991-996). There is a paucity of published data on outcomes in children with PNH treated with eculizumab. The International PNH Registry (NCT01374360) is a prospective, observational study of patients with PNH regardless of age, and represents the largest cohort of pediatric PNH patients. The objective of this analysis was to evaluate outcomes after initiation of eculizumab in pediatric patients and adult patients enrolled in the Registry. Methods: The analysis included eculizumab-treated patients enrolled in the Registry as of May 2017. Patients were stratified by age at baseline (defined as the date of eculizumab initiation; age categories, &lt;18 and ≥18 years of age) and assessed at baseline and at last follow-up. Age at the time of disease onset, as defined by earliest reported PNH granulocyte clone, disease diagnosis, or PNH symptom, was also recorded. Patients needed ≥6 months of follow-up post-baseline to be eligible for analyses of change from baseline to last follow-up on eculizumab. Results: Of 4903 patients enrolled in the Registry as of May 1, 2017, 1725 had been treated with eculizumab and had data available on demographics and enrollment date (&lt;18 years of age at baseline, n=47; ≥18 years of age at baseline, n=1678). In both age groups, the majority of patients were female (66.0%, pediatric cohort; 52.6%, adult cohort), and the majority were white (89.1% and 81.6%, respectively). Median (quartile [Q]1, Q3) age at disease onset was 14.7 (11.0, 15.8) in the pediatric cohort and 33.3 (23.7, 48.2) in the adult cohort; median (Q1, Q3) ages at baseline were 15.8 (14.9, 17.3) and 42.0 (30.8, 57.0), respectively. Fewer pediatric patients had history of thrombotic events (TEs) and other major adverse vascular events (MAVEs) at baseline compared with the adult cohort (Table), which is consistent with findings from a previous Registry analysis (Urbano-Ispizua A, et al. Haematologica. 2017;102:e76-e79). Most patients had ≥6 months of follow-up (n=44/47 [93.6%] and n=1532/1678 [91.3%], respectively) after baseline. Median (minimum, maximum) duration of time between baseline and last follow-up on eculizumab was 3.7 (0.1, 8.7) years in the pediatric cohort and 3.9 (0.0, 12.1) years in the adult cohort. Results for outcomes of interest are summarized in the Table. In both cohorts, mean lactate dehydrogenase ratio decreased from &gt;5 times the upper limit of normal at baseline to normal or near normal range at last follow-up in both age cohorts. There were no TEs reported in the pediatric cohort after baseline, but 2/43 patients (4.7%) with no history of MAVEs at baseline experienced non-TE MAVEs after baseline. Among adult patients, 19/1497 (1.3%) with no history of TEs and 7/1497 (0.5%) with history of TEs experienced TEs after baseline. Non-TE MAVEs after baseline in patients with no history of MAVEs were experienced by 17/1492 patients (1.1%) and non-TE MAVEs after baseline in patients with history of MAVEs were experienced by 15/1492 patients (1.0%). The proportion of patients requiring transfusion was lower at last follow-up in both cohorts compared with baseline (23.0% at last follow-up vs 49.3% at baseline for adults and 32.3% at last follow-up vs 48.4% at baseline for pediatric patients). A similar proportion of patients became transfusion-independent after treatment with eculizumab in both age cohorts (32.3% [10/31] in the pediatric cohort compared with 33.8% [370/1095] in the adult cohort). The proportion of patients with PNH-related symptoms decreased after baseline in both cohorts for most of the symptoms assessed, although fewer than 10 pediatric patients had symptom data available at both baseline and last follow-up. Conclusions: The effectiveness of eculizumab for reducing intravascular hemolysis and transfusion requirements, and preventing MAVEs (including TEs) was similar in these large cohorts of pediatric patients with PNH and adults with PNH. The higher proportion of patients transfusion-dependent among the pediatric cohort may be associated with the higher likelihood of underlying aplastic anemia in pediatric patients with PNH. Table. Table. Disclosures Urbano-Ispizua: Alexion Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees. Kulasekararaj:Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Other: Travel Support . Bartels:Alexion Pharmaceuticals, Inc.: Honoraria, Other: Travel Support and is site investigator for clinical trials with the company, Research Funding. Patriquin:Ra Pharmaceuticals: Consultancy, Research Funding; Octapharma: Honoraria; Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Other: Travel Support and is site investigator for clinical trials with the company. Hoechsmann:Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding. Wilson:Alexion Pharmaceuticals, Inc.: Employment, Equity Ownership. Gustovic:Alexion Pharma GmbH: Employment, Equity Ownership. Schrezenmeier:Alexion Pharmaceuticals, Inc.: Honoraria, Research Funding. </jats:sec

Additional file 1 of Clinically important change for the FACIT-Fatigue scale in paroxysmal nocturnal hemoglobinuria: a derivation from international PNH registry patient data

Additional file 1: Table S1. Demographics and Baseline Disease Characteristics

Prognostic Value of Clone Size in Paroxysmal Nocturnal Hemoglobinuria (PNH) for Thrombotic Events in Untreated Patients in the International PNH Registry

Abstract Background/Objective: The association between paroxysmal nocturnal hemoglobinuria (PNH) granulocyte clone size at disease onset and outcomes in patients with PNH remains unclear. Most but not all reports examining the relationship have shown a positive correlation between clone size and thrombotic events [TEs] in patients with PNH, but without a clear temporal association showing the prognostic value of clone size on the risk of TEs. The ongoing International PNH Registry (NCT01374360) is the largest prospective, observational study of patients with PNH conducted to date. The objective of this analysis was to examine the relationship between PNH granulocyte clone size at disease onset and risk of thrombosis after disease onset while untreated with a complement inhibitor in patients enrolled in the Registry. Methods: The current analysis included patients enrolled in the Registry as of April 2018 who had known demographics, were untreated with complement inhibitor therapy at enrollment, and had ≥12 months of untreated follow-up after disease onset. Baseline was defined as disease onset (earliest of a reported PNH clone, date of PNH diagnosis, or reported PNH symptom), and patients were stratified into 5 cohorts based on clone size at baseline (using the earliest reported clone prior to enrollment): cohort 1, clone size: 0.01-1%; cohort 2, clone size: &gt;1-5%; cohort 3, clone size: &gt;5-10%; cohort 4, clone size: &gt;10-50%; cohort 5, clone size: &gt;50%. Event rates for TEs and all major adverse vascular events (MAVEs; including TEs) were calculated for the time period from baseline to last follow-up. Other outcomes of interest included LDH ratio (LDH/LDH upper limit of normal [ULN]), hemoglobin levels, platelet counts, absolute neutrophil counts, and absolute reticulocyte counts at last follow-up. Results: A total of 2489 patients were eligible for the analysis. The majority of patients in the overall study population were female (54.0% [1343/2489]) and white (79.2% [1967/2484]). Mean (standard deviation [SD]) age at PNH start ranged from 36.4 (16.53) in cohort 5 to 44.2 (20.70) in cohort 1. Median time from baseline to last follow-up was 3.7 years in cohort 1, 4.3 years in cohort 2, 4.7 years in cohort 3, 5.6 years in cohort 4, and 6.8 years in cohort 5. Results for the outcomes of interest are summarized in the Table. All cohorts showed a risk of MAVE and TE during follow-up. Although estimated rates of MAVE and TE were highest in the &gt;50% clone size cohort, there was no difference in the rate of MAVE or TE during follow-up across the 4 cohorts with clone size &lt;50% at disease onset. Mean LDH ratio (LDH/LDH ULN) at last follow-up showed a statistically significant difference by clone size at baseline among the cohorts, ranging from a mean (SD) of 1.1 (1.34) in the patients with clone size &lt;1% and increasing to 5.1 (3.81) in the patients with clone size &gt;50% (P&lt;0.0001). No difference in hemoglobin level at last follow-up was observed in the smaller clone size cohorts, although mean hemoglobin level was lower in patients with clone size &gt;50% (P&lt;0.0001). Similar trends were seen in mean platelet and absolute neutrophil counts across the smaller clone size cohorts, while patients with clone size &gt;50% showed higher values (P&lt;0.0001). Mean absolute reticulocyte count at last follow-up was lowest in patients with clone size 0.01-1%, and were incrementally higher in each successive clone-size cohort (P&lt;0.0001). Conclusions: In this study, all patients with a PNH clone at disease onset were at risk for TEs and other MAVEs. Patients in the highest baseline PNH clone size strata (clone size &gt;50%) had an approximately 2-times higher risk of TEs than patients with smaller clone sizes; Patients with small clone sizes (0.01-1%) were older and showed a higher prevalence of BMD. There was no difference in the prognostic value of clone size at disease onset on the risk of TEs and other MAVEs in patients with small (0.01-1% and 1-5%) versus medium-sized (5-10% or 10-50%) clones. Table Table. Disclosures Peffault De Latour: Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Pfizer Inc.: Consultancy, Honoraria, Research Funding; Amgen Inc.: Research Funding. Maciejewski:Alexion Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Alexion Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Apellis Pharmaceuticals: Consultancy; Apellis Pharmaceuticals: Consultancy; Ra Pharmaceuticals, Inc: Consultancy; Ra Pharmaceuticals, Inc: Consultancy. Kulasekararaj:Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Other: Travel Support . Larratt:Alexion Pharmaceuticals, Inc.: Honoraria, Research Funding. Dingli:Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Wilson:Alexion Pharmaceuticals, Inc.: Employment, Equity Ownership. Gustovic:Alexion Pharma GmbH: Employment, Equity Ownership. Kulagin:Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria. </jats:sec