Kulasekararaj, Austin

Myelodysplastic syndromes with isolated deletion of chromosome 5q [MDS-del(5q)] constitute a distinct biological entity traditionally associated with favorable outcomes, although up to one quarter of patients progress to acute myeloid leukemia (AML). Existing prognostic models, developed in heterogeneous MDS populations, may not adequately capture risk within this subgroup. We assembled an international cohort of 682 patients with MDS-del(5q) to evaluate the performance of the IPSS-R and IPSS-M, identify prognostic variables, and develop a disease-specific prognostic tool, the IPSS-del(5q). Most patients were classified as lower-risk by IPSS-R (94.4%) and IPSS-M (85.5%), yet both systems showed limited discriminatory ability (C-indices ≈0.5). Independent adverse prognostic factors included age ≥70 years, male sex, anemia (hemoglobin ≤10 g/dL), thrombocytopenia (platelets ≤100×10⁹/L), the presence of one additional chromosomal abnormality, ≥2 gene mutations, SF3B1 mutations, and high-risk TP53 status. Six variables were included in the IPSS-del(5q), stratifying patients into standard-risk (74.3%) and high-risk (25.7%) groups with significantly different LFS (69.2 vs. 32.0 months; p<0.01). Moreover, this model reclassified 19.1% of lower-risk IPSS-R and 14.6% of lower-risk IPSS-M patients into the high-risk IPSS-del(5q) group. However, its discriminative power remained modest, with a C-index of 0.60. Overall, this study provides the most comprehensive prognostic evaluation of MDS-del(5q) to date, demonstrates the limited discriminatory capacity of existing MDS scores in this entity, and underscores the need to develop refined disease-specific prognostic approaches for this MDS subtype.

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.