MO529: The Differential Effect of Third Generation Intravenous Iron Preparations (Ferric Carboxymaltose, Ferric Derisomaltose) on Patient Related Outcome Measures in Patients With Non-Dialysis Dependent CKD and Iron Deficiency Anaemia
Authors: Kassianides Xenophon , Bhandari Sunil 
Published: May 2022

Abstract

BACKGROUND AND AIMS
A frequent complication of chronic kidney disease (CKD) is iron deficiency anaemia. This affects not only patient mortality, morbidity and disease progression, but also quality of life. Patient-related outcome measures and functional status are important measures of assessment in modern research. Evidence from patients with heart failure have demonstrated that treatment of iron deficiency leads to improved functional status, whilst in observational studies in non-dialysis dependent CKD (ND-CKD) iron replenishment has led to improvement in quality of life. As newer intravenous (IV) iron products [e.g. ferric carboxymaltose (FCM) and ferric derisomaltose (FDI)] are now in use, allowing efficacious and quick iron supplementation, a differential effect on phosphate has been noted. Phosphate is a key element involved in energy production and mitochondrial function. Therefore, the comparative effect between such compounds needs to be explored.

METHOD
The exploratory single-center double-blinded randomized controlled trial ‘Iron and Phosphaturia—ExplorIRON-CKD’ assessed the differential effects of FCM and FDI on fibroblast growth factor 23 and phosphate. Non-dialysis patients with CKD and iron deficiency with/without anaemia defined as serum ferritin &lt;200 µg/L or transferrin saturation ≤ 20% and serum ferritin 200–299 µg/L were recruited and randomized in a 1:1 ratio. Participants received 1000 mg at baseline and 500–1000 mg at 1 month to achieve replenishment. Quality of life was assessed using the Short-Form (SF)-36 questionnaire, whilst fatigue severity was monitored using the fatigue severity scale (FSS) utilizing both a scored questionnaire and a visual analogue scale. Functional status was evaluated using the Duke Activity Status Index (DASI) and the 1-minute-sit-to-stand test at baseline, 1 month, 2 months and 3 months.

RESULTS
Twenty-six patients were recruited; 14 were randomized to receive FDI and 12 to receive FCM. All patients received at least one iron dose (1000 mg), 10 patients received two FDI doses and 11 received two FCM doses. Quality of life measures (SF-36 and FSS) improved in the whole population and in each IV iron group after 3 months. Seven out of eight of the SF-36 domains improved numerically. Fatigue severity scale scores improved by ∼20% in both groups within 1 month lasting until the end of the study, whilst an improvement in the visual analogue scale was observed, which was greater in the FDI group [FDI: baseline: 3.0 (6.0); 3 months: 7.0 (4.5) versus FCM: baseline: 4.5 (2.0); 3 months: 5.0 (2.5); P-value 3 months: 0.16) (Figure 1). The DASI remained largely unaffected following IV iron. One-minute-sit-to-stand improved in the total population and within each group [mean % change baseline to 3 months: 52.5 (53.7)%], with values remaining higher than baseline throughout the study (Figure 2). No significant differences were found between the two groups in either quality of life or functional status.

CONCLUSION
In this study, patients with non-dialysis CKD and iron deficiency with/without anaemia who received a high dose of either FDI or FCM had numerical improvements in measures of quality of life and functional status. The beneficial effects on these patient-related outcomes and functional status were similar between the IV iron groups, irrespective of the potential for hypophosphataemia that FCM therapy poses. This may be due to the potential decreased hypophosphataemic effect in CKD, secondary to impaired phosphate excretion. This exploratory study, despite the small sample size highlighting the importance of caution upon generalization of results, suggests that IV iron in non-dialysis CKD is associated with improvement in patient-related outcome measures, likely secondary to improvement in haematinic parameters.