The FDA has approved the sodium/hydrogen exchanger 3 (NHE3) inhibitor tenapanor (Xphozah – Ardelyx) to reduce serum phosphorus in adults with chronic kidney disease (CKD) on dialysis as add-on therapy when phosphate binders are ineffective or as monotherapy when phosphate binders cannot be tolerated. Tenapanor is the first NHE3 inhibitor to be approved in the US for hyperphosphatemia. It was previously approved as Ibsrela to treat irritable bowel syndrome with constipation (IBS-C).

The FDA is requiring a boxed warning in the label of denosumab (Prolia – Amgen), a monoclonal antibody that inhibits osteoclasts, about an increased risk of severe hypocalcemia in patients with advanced chronic kidney disease (CKD; eGFR <30 mL/min/1.73 m²), particularly those on dialysis. FDA-approved indications for Prolia are listed in Table 1.

The FDA has approved daprodustat (Jesduvroq – GSK), a hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI), for oral treatment of anemia due to chronic kidney disease (CKD) in adults who have been on dialysis for at least 4 months. It is the first HIF-PHI and the first oral drug to be approved in the US for this indication.

The sodium-glucose cotransporter 2 (SGLT2) inhibitor empagliflozin (Jardiance – Boehringer Ingelheim/Lilly) is now FDA-approved to reduce the risk of sustained eGFR decline, end-stage kidney disease, cardiovascular death, and hospitalization in adults with chronic kidney disease (CKD) at risk of progression. It is also approved to improve glycemic control in patients ≥10 years old with type 2 diabetes, to reduce the risk of cardiovascular death and hospitalization for heart failure (HF) in adults with HF, and to reduce the risk of cardiovascular death in adults with type 2 diabetes and established cardiovascular disease.

Recently published guidelines from the American Diabetes Association (ADA) and the Kidney Disease: Improving Global Outcomes (KDIGO) Diabetes Work Group recommend addition of the oral nonsteroidal mineralocorticoid receptor antagonist (MRA) finerenone (Kerendia) to standard treatment in patients with type 2 diabetes and chronic kidney disease (CKD).

Difelikefalin (Korsuva – Vifor), an IV kappa opioid receptor (KOR) agonist, has been approved by the FDA for treatment of moderate to severe pruritus associated with chronic kidney disease (CKD) in adults on hemodialysis. It is the first drug to be approved for this indication and the first KOR agonist to become available in the US. Difelikefalin has not been studied in patients on peritoneal dialysis.

Finerenone (Kerendia – Bayer), an oral nonsteroidal mineralocorticoid receptor antagonist (MRA), has been approved by the FDA to reduce the risk of sustained eGFR decline, end-stage renal disease, nonfatal MI, hospitalization for heart failure (HF), and cardiovascular death in adults with chronic kidney disease (CKD) associated with type 2 diabetes. It is the first nonsteroidal MRA to be approved in the US.

The sodium-glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin (Farxiga – AstraZeneca) has been approved by the FDA for treatment of adults with chronic kidney disease (CKD) at risk of progression (not defined in the label). Dapagliflozin is the first SGLT2 inhibitor to be approved in the US for treatment of CKD.

Proton pump inhibitors (PPIs), which are used for treatment of gastroesophageal reflux disease (GERD) and for prevention of upper gastrointestinal adverse effects caused by NSAIDs and aspirin, are one of the most commonly prescribed classes of drugs in the US. All PPIs are similarly effective and generally well tolerated, but their long-term use has been associated with a number of safety concerns. Recommendations addressing these concerns have recently been published.

The FDA has approved ferric pyrophosphate citrate solution (Triferic – Rockwell Medical) to maintain hemoglobin concentrations in adults with hemodialysis-dependent chronic kidney disease. Triferic is the first iron replacement product that is added into the hemodialysis solution at each dialysis procedure.

The FDA has approved extended-release (ER) calcifediol (25-hydroxyvitamin D3; Rayaldee – Opko), a prohormone of calcitriol, the active form of vitamin D3. It is indicated for treatment of secondary hyperparathyroidism (SHPT) in adults with stage 3 or 4 chronic kidney disease (CKD) who have serum total 25-hydroxyvitamin D levels <30 ng/mL.

The FDA has approved the erythropoiesis-stimulating agent (ESA) peginesatide (Omontys – Affymax/Takeda), a synthetic peptide analog of erythropoietin, for treatment of anemia in patients with chronic kidney disease (CKD) who are on dialysis. Peginesatide is the third ESA to become available in the US.Overuse of the other two, which have broader indications, has been a concern.

An FDA advisory committee has voted in favor of approving ezetimibe/simvastatin (Vytorin – Merck) for prevention of major cardiovascular events in patients with chronic kidney disease who are not on dialysis. The FDA itself is expected to make a decision on this potential new indication in the first quarter of 2012.

The manufacturer’s application for this new indication was based on a double-blind, randomized trial (SHARP) that compared the combination of ezetimibe 10 mg and simvastatin 20 mg with placebo in 9270 patients with chronic kidney disease who did not have a history of myocardial infarction or coronary revascularization.1 About one-third of patients were already on hemodialysis at the start of the trial. Over a median of 4.9 years, a major atherosclerotic event (the primary endpoint) occurred in 526 patients (11.3%) taking the active drugs and in 619 (13.4%) taking placebo. Myopathy occurred in 9 patients (0.2%) randomized to ezetimibe/simvastatin and in 5 (0.1%) of those in the placebo group, not a significant difference.

Whether simvastatin alone, which would cost much less, would similarly improve outcomes in such patients remains to be determined. The FDA advisory committee did not recommend approval of Vytorin for patients who were on hemodialysis.2 Previous trials with a statin alone in patients with end-stage renal disease on hemodialysis failed to show significant benefits in clinical outcomes.3,4

1. C Baigent et al. The effects of lowering LDL cholesterol with simvastatin plus ezetimibe in patients with chronic kidney disease (Study of Heart and Renal Protection): a randomised placebo-controlled trial. Lancet 2011; 377: 2181.

2. S Sutter. Merck’s bid for Vytorin CV benefit claim muddled by earlier statin failures in dialysis patients. The Pink Sheet, November 7, 2011.

3. C Wanner et al. Atorvastatin in patients with type 2 diabetes mellitus undergoing hemodialysis. N Engl J Med 2005; 353:238.

4. BC Fellström et al. Rosuvastatin and cardiovascular events in patients undergoing hemodialysis.N Engl J Med 2009; 360:1395.

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In the Medical Letter article on Ferumoxytol (Feraheme) - A New Parenteral Iron Formulation (2010; 52:23), the last sentence of the Dosage, Administration and Cost paragraph should have listed the cost of 1 gram of sodium ferric gluconate (Ferrlecit) as about $600.

Ferumoxytol (Fer yoo mox’ i tole; Feraheme – AMAG), an intravenous (IV) iron replacement product, has been approved by the FDA for treatment of iron deficiency anemia in adults with chronic kidney disease. Iron deficiency anemia is common in chronic kidney disease and may be associated with decreased absorption from the gastrointestinal tract, limiting the usefulness of oral iron replacement. IV iron replacement can lower the dose requirement for erythropoiesis-stimulating drugs, particularly in patients on dialysis

Sevelamer carbonate (Renvela – Genzyme), a buffered form of the anion-exchange resin sevelamer hydrochloride (Renagel – Genzyme),1 has been approved by the FDA for use in patients with chronic kidney disease on dialysis. According to the manufacturer, Renvela will replace Renagel, which has been shown to induce or exacerbate metabolic acidosis in patients on dialysis. Two randomized, crossover studies found the two sevelamer salts equivalent in their ability to lower serum phosphate.2,3 Patients taking the carbonate had higher serum bicarbonate concentrations and fewer gastrointestinal adverse effects. Sevelamer carbonate, which is available in 800-mg tablets, can be substituted for the hydrochloride salt gram for gram. Recent studies in patients beginning hemodialysis have suggested a possible mortality benefit for sevelamer compared to less expensive calcium- based phosphate binders,4,5 but some critics are skeptical.6

1. Phosphate binders. Med Lett Drugs Ther 2006; 48:15.
2. J Delmez et al. A randomized, double-blind, crossover design study of sevelamer hydrochloride and sevelamer carbonate in patients on hemodialysis. Clin Nephrol 2007; 68:386.
3. S Fan et al. Renvela (sevelamer carbonate) powder and Renagel (sevelamer hydrochloride) tablets: report of a randomized, cross-over study in chronic kidney disease (CKD) patients on hemodialysis (poster). American Society of Nephrology Renal Week. October 31- November 5 2007. San Francisco.
4. GA Block et al. Mortality effect of coronary calcification and phosphate binder choice in incident hemodialysis patients. Kidney Int 2007; 71:438.
5. AM Borzecki et al. Survival in end stage renal disease: calcium carbonate vs. sevelamer. J Clin Pharm Ther 2007; 32:617.
6. J Silver. The details bedevil DCOR. Kidney Int 2007; 72:1041.

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The erythropoiesis-stimulating agents (ESAs) epoetin alfa (Epogen, Procrit) and darbepoetin alfa (Aranesp) are widely used for treatment of anemia and to reduce the need for red blood cell transfusions. Based on the results of recent clinical trials indicating an increased risk of serious adverse events and death associated with ESAs, particularly when used to achieve a hemoglobin concentration ≥12 g/dL, the FDA has revised the prescribing information for these drugs to include a black box warning.