The FDA made its decision based on data from a phase 3 trial including more than 200 patients.
Steven Fishbane, MD
The US Food and Drug Administration (FDA) announced that it has approved a supplemental new drug application for ferric citrate (Auryxia, Keryx Biopharmaceuticals) for the treatment of iron deficiency anemia in patients with non-dialysis dependent chronic kidney disease (CKD).
Ferric citrate was approved by the FDA previously in 2014 for the control of serum phosphorus levels in adults with CKD on dialysis. The decision for the new indication was made based on data from a phase 3 trial involving 234 adults with non-dialysis dependent CKD in stages 3 to 5. During the trial, patients were prohibited from receiving intravenous (IV) or oral iron and erythropoiesis-stimulating agents (ESAs). Ferric citrate increased hemoglobin levels of >1 g/dL at any point in the 24 weeks in 52.1% of patients (n = 61) compared to 19% with placebo.
“We are pleased with the broad indication permitted by the FDA, as a first-line treatment option for adults with iron deficiency anemia and chronic kidney disease, not on dialysis,” John Neylan, MD, the senior vice president and chief medical officer of Keryx Biopharmaceuticals said in a statement. “Physicians and their patients now have a new treatment option to help manage a serious complication of this complex disease.”
Additionally, data from a 16-week phase 3 study that examined ferric citrate utilization in adults with CKD, but not on dialysis was recently presented at ASN Kidney Week 2017 in New Orleans, Louisiana.
The poster data at Kidney Week showed that 2395 patients with CKD that started ferric citrate as a phosphate binder experienced a mean decrease of serum phosphorus to ~6.4 mg/dL from ~6.7 mg/dL at baseline. As related to its new indication, the overall IV iron and ESAs decreased at each follow-up period at 3, 6, and 9 months.
Additionally, the 200 patients that received ferric citrate for the full 9 months saw a steady decline in average IC iron and ESA doses during each follow-up, with iron doses decreasing by an average of 20% at 3 months, 50% at 6 months, and 60% at 9 months.
“Conclusions in this poster confirm the reductions in the use of IV iron and ESA observed in our pivotal Phase 3 study in patients with CKD on dialysis published in the July 2014 issue of the Journal of the American Society of Nephrology,” Neylan said. “These real-world insights from a large number of patients improve the understanding of Auryxia and further demonstrate the ability of Auryxia to treat hyperphosphatemia and the value this medicine can bring to payers, physicians, and patients.”
The drug has an effect on fibroblast growth factor (FGF23), a phosphate-regulating hormone linked to CDK progression and an emerging biomarker for CDK. According to Geoffrey Block, MD, the director of clinical research at Denver Nephrology, having a potential oral therapy for iron deficiency anemia could be very important in CDK management.
Also presented at Kidney Week were the results from a phase 2 study on QPI-1002 (Quark Pharmaceuticals), an investigational therapy for acute kidney injury (AKI) following cardiac surgery, which otherwise has no currently approved treatments.
“More than half of the approximate 30 million people in the United States living with chronic kidney disease are iron deficient, and yet, this is the only tablet that has been developed and approved specifically to address iron deficiency anemia in these patients, who are not on dialysis,” Steven Fishbane, MD, chief, division of kidney diseases and hypertension, department of medicine, Northwell Health, Great Neck, NY, told MD Magazine. “Starting today, physicians can prescribe an oral iron medicine to help people living with this condition, the majority of whom are not being optimally treated.”