Latour, Régis Peffault de

ABSTRACT Background Paroxysmal nocturnal haemoglobinuria (PNH) is an ultra‐rare, acquired non‐malignant haematological disorder characterised by thrombosis risk, serious complications and debilitating symptoms in untreated patients. Objective This anchored indirect treatment comparison (ITC) evaluated efficacy data between proximal complement 3 inhibitor (C3i) pegcetacoplan and factor B inhibitor, iptacopan, in patients with PNH previously treated with complement 5 inhibitors (C5i; eculizumab, ravulizumab). Methods Respective pivotal studies provided patient‐level trial data for pegcetacoplan (16‐week PEGASUS [NCT03500549]) and published data for iptacopan (24‐week APPLY PNH [NCT04558918]). Differences in study design, duration and statistical methods between PEGASUS and APPLY PNH necessitated the comparative analyses to be conducted on secondary measures based on haemoglobin (Hb) levels, absolute reticulocyte count (ARC), lactate dehydrogenase (LDH) levels, and patient‐reported outcomes on the Functional Assessment of Chronic Illness Therapy–Fatigue (FACIT‐Fatigue) scale scores. The availability of a common reference C5i treatment group in both PEGASUS and APPLY PNH studies allowed anchored ITC (Bucher method). Simulated treatment comparison (STC) assessed the robustness of the main analysis. Results Overall, baseline characteristics of the populations in the PEGASUS and APPLY PNH studies were broadly comparable. Anchored ITC showed comparable outcomes (mean difference, [95% CI]) on change‐from‐baseline to end of study for pegcetacoplan versus C5i, and iptacopan versus C5i, respectively, across endpoints: Hb level ( − 0.49 g/dL [ − 1.78, 0.80]); ARC ( – 34.41 × 10 9 /L [ − 90.02, 21.21]); LDH level ( − 115.16 U/L [ − 244.40, 14.01]); FACIT‐Fatigue score (3.57 [ − 5.60, 12.73]). Finally, the STC produced results consistent with the main Bucher analyses across all clinical endpoints and patient‐reported fatigue, providing similar point estimates and confidence intervals. Conclusion This anchored ITC, based on data from pivotal trials, did not indicate significant differences in clinical or patient‐reported outcomes between pegcetacoplan and iptacopan in PNH treatment. The findings suggest that PNH treatment decisions should also consider individualised disease‐ and patient‐related factors. Trial Registration: ClinicalTrials.gov identifier: NCT03500549.

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: >1-5%; cohort 3, clone size: >5-10%; cohort 4, clone size: >10-50%; cohort 5, clone size: >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 >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 <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 <1% and increasing to 5.1 (3.81) in the patients with clone size >50% (P<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 >50% (P<0.0001). Similar trends were seen in mean platelet and absolute neutrophil counts across the smaller clone size cohorts, while patients with clone size >50% showed higher values (P<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<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 >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.

Background:In paroxysmal nocturnal hemoglobinuria (PNH), the granulocyte clone size is often used as an indicator of disease severity. However, the prognostic value of changing clone size on clinical outcomes in PNH is not well understood.Aims:To assess the prognostic value of change in PNH granulocyte clone size on the risk of developing major adverse vascular events (MAVE) or high disease activity (HDA: elevated hemolysis [lactate dehydrogenase {LDH} ≥1.5 x upper limit of normal] and one or more PNH‐related symptom[s]) in patients with PNH.Methods:The International PNH Registry is the largest worldwide observational study of patients with a diagnosis of PNH or a detected PNH clone as low as 0.01%. This study assessed patients with a baseline value for PNH clone size (defined as the closest value to disease onset) and at least one additional clone size value, who were untreated with complement inhibitor therapy at enrollment, and had ≥12 months of untreated follow‐up. Patients were stratified by clone size at baseline and change in clone size was estimated using regression models of clone size vs duration from disease start, adjusted for baseline clone size. Patients were categorized as having stable, increasing, or decreasing clone size depending on the slope, where a change in clone size >10% per year was considered increasing/decreasing. Prognostic value of change in clone size was assessed using Poisson regression to estimate rate ratios of MAVE and logistic regression to estimate odds ratios of HDA during follow‐up, with stable clone size as the reference. Adjusted models included baseline LDH ratio category, history of bone marrow disease at baseline, baseline clone size, and duration.Results:As of April 3, 2018, a total of 1894 patients were available for analysis: cohort (COH) 1 (clone size >0.01% to ≤1%, n = 381); COH 2 (clone size >1% to ≤5%, n = 318); COH 3 (clone size >5% to ≤10%, n = 159); COH 4 (clone size >10% to ≤50%, n = 480); COH 5 (clone size >50% to ≤100%, n = 556). Median duration was 3.5 years. Clone size was stable in only 16.2% of patients, as compared with 45.3% increasing and 38.5% decreasing; stable clone size was primarily seen in patients with a clone size ≤1% at baseline (58% of patients in COH 1 with a stable clone), with less than 10% of patients with a stable clone in the other cohorts. Clone size change over time was highly prognostic of HDA; patients with increasing and decreasing clone size had an increased risk of HDA, compared to patients with stable clone size, although this may be due to patients with a stable clone largely in COH 1 with a low risk of HDA; after adjusting, we see no increased risk of HDA in patients with decreasing clone size, but the increased risk of HDA in patients with increasing clone size is maintained (Table). Due to limited data on covariates at baseline, only 156 patients were available for this adjusted analysis. There was no difference in the MAVE rate in patients with increasing or decreasing clone size as compared with those with a stable clone size. The lack of effect was maintained even after adjusting for covariates (Table).Summary/Conclusion:This is the first analysis of the prognostic value of PNH clone size changes on clinical outcomes over time in patients with PNH. Increasing clone size over time was predictive of patients experiencing HDA during their disease course. Interestingly, no difference in the MAVE rate was seen in patients with increasing or decreasing clone size, suggesting that change in clone size does not change the increased risk of MAVE in patients with PNH.image