doxercalciferol 0.0005 MG Oral Capsule

INDICATIONS AND USAGE Doxercalciferol capsules are indicated for the treatment of secondary hyperparathyroidism in adult patients with Stage 3 or Stage 4 chronic kidney disease (CKD) and adult patients with CKD on dialysis. Doxercalciferol Capsules is a synthetic vitamin D 2 analog: Doxercalciferol capsules are indicated for the treatment of secondary hyperparathyroidism in adult patients with Stage 3 or Stage 4 chronic kidney disease (CKD) and adult patients with CKD on dialysis. ( 1 )

DOSAGE AND ADMINISTRATION Before initiating treatment, ensure serum calcium is not above the upper limit of normal. ( 2.1 ) Dosage for doxercalciferol capsules in patients with: Stage 3 or 4 CKD: Initiate dosing at 1 mcg orally once daily. Maximum dose is 3.5 mcg once daily. ( 2.2 ) CKD on dialysis: Initiate dosing at 10 mcg orally three times weekly at dialysis (no more frequently than every other day). Maximum dose is 20 mcg three times weekly for a total of 60 mcg weekly. ( 2.3 ) Target the maintenance dose of doxercalciferol to intact parathyroid hormone (PTH) levels within the desired therapeutic range and serum calcium within normal limits. ( 2 ) See Full Prescribing Information for dose titration, laboratory monitoring, and important administration instructions. ( 2 ) 2.1 Prior to Initiation of Doxercalciferol Capsules Ensure serum calcium is not above the upper limit of normal before initiating treatment with doxercalciferol capsules [see Warnings and Precautions ( 5.1 )]. 2.2 Dosage Recommendations for Doxercalciferol Capsules in Patients with Stage 3 or 4 CKD Initiate doxercalciferol capsules at a dose of 1 mcg orally once daily. Target the maintenance dose of doxercalciferol to intact parathyroid hormone (PTH) levels within the desired therapeutic range and serum calcium within normal limits. Monitor serum calcium, phosphorus, and intact PTH levels at least every two weeks for 3 months after initiation of therapy or dose adjustment, then monthly for 3 months, and every 3 months thereafter. Titrate the dose of doxercalciferol capsules based on intact PTH. The dose may be increased at 2-week intervals by 0.5 mcg to achieve the desired therapeutic range of intact PTH. The maximum recommended dose of doxercalciferol capsules is 3.5 mcg administered once daily. Prior to raising the dose, ensure serum calcium is within normal limits. Suspend or decrease the dose if intact PTH is persistently and abnormally low to reduce the risk of adynamic bone disease [see Warnings and Precautions ( 5.4 )] or if serum calcium is consistently above the normal range to reduce the risk of hypercalcemia [see Warnings and Precautions ( 5.1 )]. If suspended, the drug should be restarted after one week at a dose that is at least 0.5 mcg lower. 2.3 Dosage Recommendations for Doxercalciferol Capsules in Patients with CKD on Dialysis Initiate doxercalciferol capsules at a dose of 10 mcg orally administered three times weekly at dialysis (no more frequently than every other day). Target the maintenance dose of doxercalciferol to intact parathyroid hormone (PTH) levels within the desired therapeutic range and serum calcium within normal limits. Monitor serum calcium, phosphorus, and intact PTH levels frequently (e.g., weekly) after initiation of therapy or dose adjustment. Titrate the dose of doxercalciferol capsules based on intact PTH. The dose may be increased at 8-week intervals by 2.5 mcg to achieve the desired therapeutic range of intact PTH. The maximum recommended dose of doxercalciferol is 20 mcg administered three times weekly at dialysis for a total dose of 60 mcg weekly. Prior to raising the dose, ensure serum calcium is within normal limits. Suspend or decrease the dose if intact PTH is persistently and abnormally low to reduce the risk of adynamic bone disease [see Warnings and Precautions ( 5.4 )] or if serum calcium is consistently above the normal range to reduce the risk of hypercalcemia [see Warnings and Precautions ( 5.1 )]. If suspended, the drug should be restarted one week later at a dose that is at least 2.5 mcg lower. 2.6 Drug Interactions that May Require Dosage Adjustments of Doxercalciferol Increased monitoring of serum calcium and dose adjustment of doxercalciferol may be necessary when given concomitantly with drugs that may increase the risk of hypercalcemia [see Drug Interactions ( 7 )]. Increased monitoring of both serum calcium and intact PTH as well as dose adjustment of doxercalciferol may be necessary when given concomitantly with cytochrome P450 inhibitors or enzyme inducers [see Drug Interactions ( 7 )].

WARNINGS AND PRECAUTIONS • Hypercalcemia: Can occur during treatment with Doxercalciferol Injection and can lead to cardiac arrhythmias and seizures. Severe hypercalcemia may require emergency attention. Risk may be increased when used concomitantly with high dose calcium preparations, thiazide diuretics, or vitamin D compounds. Monitor serum calcium prior to initiation and during treatment and adjust dose accordingly. ( 2 , 5.1 ) • Digitalis Toxicity : Hypercalcemia increases the risk of digitalis toxicity. In patients using digitalis compounds, monitor serum calcium and patients for signs and symptoms of digitalis toxicity. Increase frequency of monitoring when initiating or adjusting the dose of Doxercalciferol Injection. ( 5.2 ) • Serious Hypersensitivity Reactions : Anaphylaxis, with symptoms of angioedema, hypotension, unresponsiveness, chest discomfort, shortness of breath, and cardiopulmonary arrest, has been reported in hemodialysis patients after administration of Doxercalciferol Injection. Monitor patients upon treatment initiation for hypersensitivity reactions. Should a reaction occur, discontinue and treat. ( 5.3 ) • Adynamic Bone Disease : May develop and increase risk of fractures if intact PTH levels are suppressed to abnormally low levels. Monitor intact PTH levels to avoid over suppression and adjust dose if needed. ( 5.4 ) 5.1 Hypercalcemia Hypercalcemia may occur during Doxercalciferol Injection treatment. Acute hypercalcemia may increase the risk of cardiac arrhythmias and seizures and may potentiate the effect of digitalis on the heart [see Warnings and Precautions (5.2)]. Chronic hypercalcemia can lead to generalized vascular calcification and other soft-tissue calcification. Severe hypercalcemia may require emergency attention. Hypercalcemia may be exacerbated by concomitant administration of high doses of calcium-containing preparations, thiazide diuretics, or other vitamin D compounds [see Drug Interactions (7)] . In addition, high intake of calcium and phosphate concomitantly with vitamin D compounds may lead to hypercalciuria and hyperphosphatemia. Patients with a history of hypercalcemia prior to initiating therapy may be at increased risk for development of hypercalcemia with Doxercalciferol Injection. In these circumstances, frequent serum calcium monitoring and Doxercalciferol Injection dose adjustments may be required. When initiating Doxercalciferol Injection or adjusting Doxercalciferol Injection dose, measure serum calcium frequently (weekly in patients with CKD on dialysis or every 2 weeks for patients with stage 3 or 4 CKD). Once a maintenance dose has been established, measure serum calcium monthly for 3 months and then every 3 months. If hypercalcemia occurs, reduce the dose or discontinue Doxercalciferol Injection until serum calcium is normal [see Dosage and Administration (2)] . Inform patients about the symptoms of elevated calcium (feeling tired, difficulty thinking clearly, loss of appetite, nausea, vomiting, constipation, increased thirst, increased urination and weight loss) and instruct them to report new or worsening symptoms when they occur. 5.2 Digitalis Toxicity Doxercalciferol Injection can cause hypercalcemia [see Warnings and Precautions (5.1)] which increases the risk of digitalis toxicity. In patients using Doxercalciferol Injection concomitantly with digitalis compounds, monitor both serum calcium and patients for signs and symptoms of digitalis toxicity. Increase the frequency of monitoring when initiating or adjusting the dose of Doxercalciferol Injection [see Drug Interactions (7)] . 5.3 Serious Hypersensitivity Reactions Serious hypersensitivity reactions, including fatal outcome, have been reported post marketing in patients on hemodialysis following administration of Doxercalciferol Injection. Hypersensitivity reactions include anaphylaxis with symptoms of angioedema (involving face, lips, tongue and airways), hypotension, unresponsiveness, chest discomfort, shortness of breath, and cardiopulmonary arrest. These reactions may occur separately or together. Monitor patients receiving Doxercalciferol Injection upon initiation of treatment for hypersensitivity reactions. Should a hypersensitivity reaction occur, discontinue Doxercalciferol Injection, monitor and treat if indicated [see Contraindications (4)] . 5.4 Adynamic Bone Disease Adynamic bone disease with subsequent increased risk of fractures may develop if intact PTH levels are suppressed by Doxercalciferol Injection to abnormally low levels. Monitor intact PTH levels to avoid over suppression and adjust the Doxercalciferol Injection dose, if needed [see Dosage and Administration (2)] .

CONTRAINDICATIONS Doxercalciferol Injection is contraindicated in patients with: Hypercalcemia [see Warnings and Precautions (5.1)] Vitamin D toxicity [see Warnings and Precautions (5.1)] Known hypersensitivity to doxercalciferol or any of the inactive ingredients of Doxercalciferol Injection; serious hypersensitivity reactions including anaphylaxis and angioedema have been reported [see Warnings and Precautions (5.3), Adverse Reactions (6.2)]. • Hypercalcemia ( 4 ) • Vitamin D toxicity ( 4 ) • Know hypersensitivity to doxercalciferol or any of the inactive ingredients of Doxercalciferol Injection ( 4 )

CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Doxercalciferol is a synthetic vitamin D 2 analog that requires metabolic activation to form the active 1α,25-(OH) 2 D 2 metabolite, which binds to the vitamin D receptor (VDR) to result in the selective activation of vitamin D responsive pathways. Vitamin D and doxercalciferol have been shown to reduce PTH levels by inhibiting PTH synthesis and secretion. 12.3 Pharmacokinetics Absorption In healthy volunteers, peak blood levels of 1α,25-(OH) 2 D 2 , the major metabolite of doxercalciferol, are attained at 8 hours after a single intravenous dose of doxercalciferol and at 11 to 12 hours following capsule doses. Elimination The mean elimination half-life of 1α,25-(OH)2D 2 after an oral dose is approximately 32 to 37 hours with a range of up to 96 hours. Metabolism Doxercalciferol is activated by CYP 27 in the liver to form 1α,25-(OH) 2 D 2 (major metabolite) and 1α,24-dihydroxyvitamin D 2 (minor metabolite). Activation of doxercalciferol does not require the involvement of the kidneys. Specific Populations Patients with renal impairment The mean elimination half-life of 1α,25-(OH) 2 D 2 in patients with end-stage renal disease (ESRD) and in healthy volunteers appears to be similar following an oral dose. Hemodialysis causes a temporary increase in 1α,25- (OH) 2 D 2 mean concentrations, presumably due to volume contraction. 1α,25-(OH) 2 D 2 is not removed from blood during hemodialysis.