AURYXIA

Auryxia (ferric citrate), a phosphate binder and iron replacement product, is known chemically as iron (+3), x (1, 2, 3-propanetricarboxylic acid, 2 hydroxy-), y (H 2 O) Auryxia 210 mg ferric iron tablets for oral administration, equivalent to 1g ferric citrate, are film-coated, peach-colored, and oval-shaped tablets debossed with “KX52.” The inactive ingredients are pregelatinized starch and calcium stearate. In addition, the film-coating contains the following inactive ingredients: hypromellose, titanium dioxide, triacetin, and FD&C Yellow #6/Sunset Yellow FCF Aluminum Lake, FD&C Red #40/Allura Red AC Aluminum Lake, and FD&C Blue #2/Indigo Carmine Aluminum Lake. Ferric Citrate Structure

Auryxia is a phosphate binder indicated for the control of serum phosphorus levels in adult patients with chronic kidney disease on dialysis. ( 1 ) Auryxia is an iron replacement product indicated for the treatment of iron deficiency anemia in adult patients with chronic kidney disease not on dialysis. ( 1 ) 1.1 Hyperphosphatemia in Chronic Kidney Disease on Dialysis Auryxia is indicated for the control of serum phosphorus levels in adult patients with chronic kidney disease on dialysis. 1.2 Iron Deficiency Anemia in Chronic Kidney Disease Not on Dialysis Auryxia is indicated for the treatment of iron deficiency anemia in adult patients with chronic kidney disease not on dialysis.

Hyperphosphatemia in Chronic Kidney Disease on Dialysis: Starting dose is 2 tablets orally 3 times per day with meals. ( 2.1 ) Adjust dose by 1 to 2 tablets as needed to maintain serum phosphorus at target levels, up to a maximum of 12 tablets daily. Dose can be titrated at 1-week or longer intervals. ( 2.1 ) Iron Deficiency Anemia in Chronic Kidney Disease Not on Dialysis: Starting dose is 1 tablet orally 3 times per day with meals. ( 2.2 ) Adjust dose as needed to achieve and maintain hemoglobin goal, up to a maximum of 12 tablets daily. ( 2.2 ) 2.1 Dosage for Hyperphosphatemia in Chronic Kidney Disease on Dialysis The recommended starting dose is 2 tablets, swallowed whole, 3 times per day with meals. Auryxia tablets must not be chewed or crushed because it may cause discoloration of mouth and teeth. Monitor serum phosphorus levels and titrate the Auryxia dose in decrements or increments of 1 to 2 tablets per day as needed to maintain serum phosphorus at target levels, up to a maximum dose of 12 tablets daily. Dose can be titrated at 1-week or longer intervals. In a clinical trial, patients required an average of 8 to 9 tablets a day to control serum phosphorus levels. 2.2 Dosage for Iron Deficiency Anemia in Chronic Kidney Disease Not on Dialysis The recommended starting dose is 1 tablet, swallowed whole, 3 times per day with meals. Auryxia tablets must not be chewed or crushed because it may cause discoloration of mouth and teeth. Titrate the dose of Auryxia as needed to achieve and maintain hemoglobin at target levels, up to a maximum dose of 12 tablets daily. In a clinical trial in patients with chronic kidney disease not on dialysis (CKD-NDD), patients required an average of 5 tablets per day to increase hemoglobin levels.

Auryxia is contraindicated in patients with iron overload syndromes (e.g., hemochromatosis) [see Warnings and Precautions ( 5.1 )] . Iron overload syndromes (e.g., hemochromatosis). ( 4 )

Most common adverse reactions (incidence ≥5%) are discolored feces, diarrhea, constipation, nausea, vomiting, cough, abdominal pain, and hyperkalemia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Keryx Biopharmaceuticals at 1-844-445-3799 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to adverse reaction rates in the clinical trials of another drug and may not reflect the rates observed in practice. Hyperphosphatemia in Chronic Kidney Disease on Dialysis A total of 289 patients were treated with Auryxia and 149 patients were treated with active control (sevelamer carbonate and/or calcium acetate) during the 52-week, randomized, open-label, active control phase of a trial in patients on dialysis. A total of 322 patients were treated with Auryxia for up to 28 days in three short-term trials. Across these trials, 557 unique patients were treated with Auryxia; dosage regimens in these trials ranged from 210 mg to 2,520 mg of ferric iron per day, equivalent to 1 to 12 tablets of Auryxia. Adverse reactions reported in more than 5% of patients treated with Auryxia in these trials included diarrhea (21%), discolored feces (19%), nausea (11%), constipation (8%), vomiting (7%), and cough (6%). During the 52-week, active-control period, 61 patients (21%) on Auryxia discontinued study drug because of an adverse reaction, as compared to 21 patients (14%) in the active control arm. Patients who were previously intolerant to any of the active control treatments (calcium acetate and sevelamer carbonate) were not eligible to enroll in the study. Gastrointestinal adverse reactions were the most common reason for discontinuing Auryxia (14%). Iron Deficiency Anemia in Chronic Kidney Disease Not on Dialysis Across two trials, 190 patients with CKD-NDD were treated with Auryxia. This included a study of 117 patients treated with Auryxia and 116 patients treated with placebo in a 16-week, randomized, double-blind period and a study of 75 patients treated with Auryxia and 73 treated with placebo in a 12-week randomized double-blind period. Dosage regimens in these trials ranged from 210 mg to 2,520 mg of ferric iron per day, equivalent to 1 to 12 tablets of Auryxia. Adverse reactions reported in at least 5% of patients treated with Auryxia in these trials are listed in Table 1. Table 1: Adverse Events Reported in Two Clinical Trials in at least 5% of patients receiving Auryxia Body System Adverse Reaction Auryxia % (N=190) Placebo % (N=188) Any Adverse Reaction 75 62 Metabolism and Nutrition Disorders Hyperkalemia 5 3 Gastrointestinal Disorders Discolored feces 22 0 Diarrhea 21 12 Constipation 18 10 Nausea 10 4 Abdominal Pain 5 2 During the 16-week, placebo-control trial, 12 patients (10%) on Auryxia discontinued study drug because of an adverse reaction, as compared to 10 patients (9%) in the placebo control arm. Diarrhea was the most common adverse reaction leading to discontinuation of Auryxia (2.6%).

Table 2: Oral drugs that can be administered concomitantly with Auryxia Amlodipine Aspirin Atorvastatin Calcitriol Clopidogrel Digoxin Diltiazem Doxercalciferol Enalapril Fluvastatin Glimepiride Levofloxacin Losartan Metoprolol Pravastatin Propranolol Sitagliptin Warfarin Oral drugs that have to be separated from Auryxia and meals Dosing Recommendations Doxycycline Take at least 1 hour before Auryxia Ciprofloxacin Take at least 2 hours before or after Auryxia Oral medications not listed in Table 2 There are no empirical data on avoiding drug interactions between Auryxia and most concomitant oral drugs. For oral medications where a reduction in the bioavailability of that medication would have a clinically significant effect on its safety or efficacy, consider separation of the timing of the administration of the two drugs. The duration of separation depends upon the absorption characteristics of the medication concomitantly administered, such as the time to reach peak systemic levels and whether the drug is an immediate release or an extended release product. Consider monitoring clinical responses or blood levels of concomitant medications that have a narrow therapeutic range. When clinically significant drug interactions are expected, consider separation of the timing of administration. Consider monitoring clinical responses or blood levels of the concomitant medication. ( 7 )

16.2 Storage and Handling Storage: Store at 20° to 25°C (68° to 77°F), excursions permitted to 15° to 30°C (59° to 86°F). [See USP controlled room temperature]. Protect from moisture.