Akebia Therapeutics has announced topline results from IMPACT, a phase 4 collaborative study investigating the impact of Auryxia (ferric citrate) when used as the primary phosphate-lowering therapy, on the utilisation of erythropoiesis-stimulating agent (ESA) and intravenous (IV) iron as well as on laboratory parameters indicative of phosphate and anaemia management compared to the standard of care (SOC) in adult patients with chronic kidney disease (CKD) on dialysis. A press release notes that Auryxia is approved for the control of serum phosphorus levels in adult patients with CKD on dialysis and for the treatment of iron deficiency anaemia in adult patients with CKD not on dialysis.
IMPACT, sponsored by US Renal Care Kidney Research in collaboration with Akebia, was a randomised, open-label, active-controlled, multicentre study in adult patients with CKD receiving either in-centre haemodialysis or home dialysis. The study enrolled 209 adult patients who were randomised 1:1 to Auryxia (starting dose of 6 tablets per day) or to remain on SOC, defined as non-Auryxia phosphate-lowering agent, for up to 6 months. The two groups had generally similar baseline characteristics with the exception of atherosclerotic cardiovascular disease and congestive heart failure, which were more common in the SOC group.
Co-primary endpoints were the difference in mean change from baseline (month -3 to Day 1) to the efficacy evaluation period (months 4–6) in monthly ESA and IV iron doses between groups. Secondary endpoints were the difference in the proportion of patients with serum phosphate ≤5.5mg/dL and haemoglobin (Hb) ≥10.0g/dL, during the efficacy evaluation period (months 4–6). Treatment with Auryxia resulted in a statistically significant difference in mean monthly ESA use (-30.82mcg/month, p=0.02) and a non-significant difference in mean monthly IV iron use (-37.02mg/month, p=0.17). There were similar proportions of patients in each group with Hb ≥10.0g/dL and serum phosphate ≤5.5mg/dL.
Three patients stopped Auryxia due to gastrointestinal intolerance (n=2) or adverse events (n=1). Serious adverse events occurred in 39% of patients receiving Auryxia and 59% in those receiving SOC.
“Results from the IMPACT study provide valuable insights into the potential impact of Auryxia in adult patients with hyperphosphataemia on dialysis. These observations are important for nephrologists who are evaluating the appropriateness of Auryxia as a phosphate-lowering agent in this patient population,” said Geoffrey Block (US Renal Care, Plano, USA). The press release states that Block plans to present the full study results at an upcoming scientific meeting.
