MedPath

Doxercalciferol

These highlights do not include all the information needed to use doxercalciferol capsules safely and effectively. See full prescribing information for doxercalciferol capsules.Doxercalciferol capsules, for oral useInitial U.S. Approval: 1999

Approved
Approval ID

2ed2f592-27a7-4c10-a18a-21a3f221d3b1

Product Type

HUMAN PRESCRIPTION DRUG LABEL

Effective Date

Oct 28, 2021

Manufacturers
FDA

Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.

DUNS: 780779901

Products 3

Detailed information about drug products covered under this FDA approval, including NDC codes, dosage forms, ingredients, and administration routes.

Doxercalciferol

Product Details

FDA regulatory identification and product classification information

FDA Identifiers
NDC Product Code23155-540
Application NumberANDA205360
Product Classification
M
Marketing Category
C73584
G
Generic Name
Doxercalciferol
Product Specifications
Route of AdministrationORAL
Effective DateOctober 28, 2021
FDA Product Classification

INGREDIENTS (10)

DOXERCALCIFEROLActive
Quantity: 2.5 ug in 1 1
Code: 3DIZ9LF5Y9
Classification: ACTIB
BUTYLATED HYDROXYANISOLEInactive
Code: REK4960K2U
Classification: IACT
ALCOHOLInactive
Code: 3K9958V90M
Classification: IACT
GELATINInactive
Code: 2G86QN327L
Classification: IACT
GLYCERINInactive
Code: PDC6A3C0OX
Classification: IACT
FERROSOFERRIC OXIDEInactive
Code: XM0M87F357
Classification: IACT
FD&C RED NO. 40Inactive
Code: WZB9127XOA
Classification: IACT
TITANIUM DIOXIDEInactive
Code: 15FIX9V2JP
Classification: IACT
SHELLACInactive
Code: 46N107B71O
Classification: IACT
MEDIUM-CHAIN TRIGLYCERIDESInactive
Code: C9H2L21V7U
Classification: IACT

Doxercalciferol

Product Details

FDA regulatory identification and product classification information

FDA Identifiers
NDC Product Code23155-539
Application NumberANDA205360
Product Classification
M
Marketing Category
C73584
G
Generic Name
Doxercalciferol
Product Specifications
Route of AdministrationORAL
Effective DateOctober 28, 2021
FDA Product Classification

INGREDIENTS (11)

DOXERCALCIFEROLActive
Quantity: 1 ug in 1 1
Code: 3DIZ9LF5Y9
Classification: ACTIB
BUTYLATED HYDROXYANISOLEInactive
Code: REK4960K2U
Classification: IACT
ALCOHOLInactive
Code: 3K9958V90M
Classification: IACT
MEDIUM-CHAIN TRIGLYCERIDESInactive
Code: C9H2L21V7U
Classification: IACT
TITANIUM DIOXIDEInactive
Code: 15FIX9V2JP
Classification: IACT
FERROSOFERRIC OXIDEInactive
Code: XM0M87F357
Classification: IACT
GLYCERINInactive
Code: PDC6A3C0OX
Classification: IACT
GELATINInactive
Code: 2G86QN327L
Classification: IACT
SHELLACInactive
Code: 46N107B71O
Classification: IACT
FD&C BLUE NO. 1Inactive
Code: H3R47K3TBD
Classification: IACT
FD&C YELLOW NO. 6Inactive
Code: H77VEI93A8
Classification: IACT

Doxercalciferol

Product Details

FDA regulatory identification and product classification information

FDA Identifiers
NDC Product Code23155-538
Application NumberANDA205360
Product Classification
M
Marketing Category
C73584
G
Generic Name
Doxercalciferol
Product Specifications
Route of AdministrationORAL
Effective DateOctober 28, 2021
FDA Product Classification

INGREDIENTS (9)

GELATINInactive
Code: 2G86QN327L
Classification: IACT
GLYCERINInactive
Code: PDC6A3C0OX
Classification: IACT
FERROSOFERRIC OXIDEInactive
Code: XM0M87F357
Classification: IACT
SHELLACInactive
Code: 46N107B71O
Classification: IACT
TITANIUM DIOXIDEInactive
Code: 15FIX9V2JP
Classification: IACT
ALCOHOLInactive
Code: 3K9958V90M
Classification: IACT
MEDIUM-CHAIN TRIGLYCERIDESInactive
Code: C9H2L21V7U
Classification: IACT
DOXERCALCIFEROLActive
Quantity: 0.5 ug in 1 1
Code: 3DIZ9LF5Y9
Classification: ACTIB
BUTYLATED HYDROXYANISOLEInactive
Code: REK4960K2U
Classification: IACT

Drug Labeling Information

PACKAGE LABEL.PRINCIPAL DISPLAY PANEL

LOINC: 51945-4Updated: 11/2/2021

PACKAGE LABEL.PRINCIPAL DISPLAY PANEL 2.5 mcg

NDC 23155-540-25

Doxercalciferol Capsules

2.5 mcg

50 Capsules

Rx only

2.5 mcg

INDICATIONS & USAGE SECTION

LOINC: 34067-9Updated: 3/1/2019

1 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.
Key Highlight

Doxercalciferol Capsules is a synthetic vitamin D2 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)

CONTRAINDICATIONS SECTION

LOINC: 34070-3Updated: 3/1/2019

4 CONTRAINDICATIONS

Doxercalciferol 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 capsules; serious hypersensitivity reactions including anaphylaxis and angioedema have been reported [see Warnings and Precautions (5.3), Adverse Reactions (6.2)].
Key Highlight
  • Hypercalcemia (4)
  • Vitamin D toxicity (4)
  • Know hypersensitivity to doxercalciferol or any of the inactive ingredients of doxercalciferol capsules (4)

ADVERSE REACTIONS SECTION

LOINC: 34084-4Updated: 9/17/2020

6 ADVERSE REACTIONS

The following adverse reactions are discussed in greater detail in another section of the label:

  • Hypercalcemia [see Warnings and Precautions (5.1)]
  • Serious Hypersensitivity Reactions [see Warnings and Precautions (5.3)]
  • Adynamic Bone Disease [see Warnings and Precautions (5.4)]

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 rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Adverse reactions in patients with stage 3 or 4 CKD

Doxercalciferol capsules have been evaluated in two placebo-controlled, double-blind 24 week studies in patients with Stage 3 or 4 CKD. Patients were treated with doxercalciferol capsules (n=27) or placebo (n=28) [see Clinical Studies (14.1)]. Adverse reactions occurring in the doxercalciferol capsules group at a frequency of 5% or greater and more frequently than in the placebo group are presented in Table 1.

Table 1: Adverse Reactions Occurring in ≥5% Doxercalciferol Capsule- Treated Patients with CKD on Predialysis and Greater than Placebo in Two Double-Blind Clinical Studies
  • Pooled data on adverse reactions from clinical study reports (Studies BCI-CH-115 and BCI-CH-119).

** Adverse Reaction*******

** Doxercalciferol (n=27)**
** %**

** Placebo (n=28)**
** %**

Infection/bacterial infection/viral infection

30

25

Constipation

26

11

Rhinitis

22

11

Anemia

19

4

Cough

19

4

Dyspnea

19

11

Paresthesia

15

11

Asthenia

15

11

Insomnia

15

4

Hypertonia

11

4

Angina pectoris

8

0

Dehydration

7

4

Depression

7

0

Dyspepsia

7

4

Edema

7

4

Urinary tract infection

7

4

Leukopenia

7

0

Chest pain

7

4

Pruritus

7

4

Sinusitis

7

4

Adverse reactions in patients with CKD on dialysis

Doxercalciferol capsules have been evaluated in two placebo-controlled, double-blind studies in patients with CKD on hemodialysis. Patients were treated with doxercalciferol capsules (n=61) or placebo (n=61) [see Clinical Studies (14.2)]. After randomization to two groups, eligible patients underwent an 8-week washout period during which no vitamin D derivatives were administered to either group. Subsequently, all patients received doxercalciferol capsules in an open-label fashion for 16 weeks followed by a double-blind period of 8 weeks during which patients received either doxercalciferol capsules or placebo. Adverse reactions occurring in the doxercalciferol capsule groups at a frequency of 2% or greater, and more frequently than in the placebo group are presented in Table 2.

Table 2: Adverse Reactions Occurring in ≥2% Doxercalciferol Capsule- Treated Patients with CKD on Dialysis and Greater than Placebo in Two Double- Blind Clinical Studies
  • A patient who reported the same medical term more than once was counted only once for that medical term.

** Adverse Reaction*******

** Doxercalciferol (n=61)**
** %**

** Placebo (n=61)**
** %**

Edema

34

21

Malaise

28

20

Headache

28

18

Nausea/Vomiting

21

20

Dizziness

12

10

Dyspnea

12

7

Pruritus

8

7

Bradycardia

7

5

Anorexia

5

3

Dyspepsia

5

2

Arthralgia

5

0

Weight increase

5

0

Abscess

3

0

Sleep disorder

3

0

6.2 Postmarketing Experience

The following adverse reactions have been identified during postapproval use of doxercalciferol. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to estimate their frequency or to establish a causal relationship to drug exposure.

Hypersensitivity reactions include anaphylaxis with symptoms of angioedema (involving face, lips, tongue and airways), hypotension, unresponsiveness, chest discomfort, shortness of breath, cardiopulmonary arrest, pruritus, and skin burning sensation.

Key Highlight

The most common adverse reactions in patients with Stage 3 or 4 CKD (incidence

5%) were infection, urinary tract infection, chest pain, angina pectoris, constipation, dyspepsia, anemia, leucopenia, dehydration, edema, depression, hypertonia, insomnia, asthenia, paresthesia, cough increased, dyspnea, pruritus, sinusitis, and rhinitis. (6.1)

The most common adverse reactions in patients with CKD on dialysis (incidence

5%) were headache, malaise, edema, nausea/vomiting, dyspnea, dizziness, pruritus, and bradycardia. (6.1)

To report SUSPECTED ADVERSE REACTIONS, contact Avet Pharmaceuticals Inc. at 1-866-901-DRUG (3784) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

DRUG INTERACTIONS SECTION

LOINC: 34073-7Updated: 3/1/2019

7 DRUG INTERACTIONS

Tables 3 and 4 include clinically significant drug interactions with doxercalciferol.

Table 3: Clinically Significant Drug Interactions with Doxercalciferol Capsules

** Drugs that May Increase the Risk of Hypercalcemia**

Clinical
Impact

Concomitant administration of high doses of calcium-containing preparations or other vitamin D compounds may increase the risk of hypercalcemia. Thiazide diuretics are known to induce hypercalcemia by reducing excretion of calcium in the urine.

Examples

Calcium-containing products, other vitamin D compounds or thiazide diuretics

Intervention

Monitor serum calcium concentrations more frequently and adjust doxercalciferol dose as needed [see Warnings and Precautions (5.1)].

** Digitalis Compounds**

Clinical
Impact

Doxercalciferol can cause hypercalcemia which can potentiate the risk of digitalis toxicity.

Intervention

Monitor patients for signs and symptoms of digitalis toxicity and increase frequency of serum calcium monitoring when initiating or adjusting the dose of doxercalciferol in patients receiving digitalis compounds [see Warnings andPrecautions (5.2)].

** Cytochrome P450 Inhibitors**

Clinical
Impact

Doxercalciferol is activated by CYP 27 in the liver. Cytochrome P450 inhibitors may inhibit the 25-hydroxylation of doxercalciferol and thus reduce the formation of active doxercalciferol moiety [see Clinical Pharmacology (12.3)].

Examples

Ketoconazole and erythromycin

Intervention

If a patient initiates or discontinues therapy with a cytochrome P450 inhibitor, dose adjustment of doxercalciferol may be necessary. Monitor intact PTH and serum calcium concentrations closely.

** Enzyme Inducers**

Clinical
Impact

Doxercalciferol is activated by CYP 27 in the liver. Enzyme inducers may affect the 25-hydroxylation of doxercalciferol [see Clinical Pharmacology (12.3)].

Examples

Glutethimide and phenobarbital

Intervention

If a patient initiates or discontinues therapy with an enzyme inducer, dose adjustment of doxercalciferol may be necessary. Monitor intact PTH and serum calcium concentrations closely.

** Magnesium-containing Products**

Clinical
Impact

Concomitant administration of doxercalciferol and high doses of magnesium- containing products may increase the risk of hypermagnesemia.

Examples

Magnesium-containing products such as antacids

Intervention

Avoid use of magnesium-containing products and doxercalciferol in patients on chronic renal dialysis.

Table 4: Clinically Significant Drug Interactions with Doxercalciferol Capsules

** Cholestyramine**

Clinical
Impact

Cholestyramine has been reported to reduce intestinal absorption of fat- soluble vitamins. Therefore, it may impair intestinal absorption of doxercalciferol capsules.

Intervention

Administer doxercalciferol capsules at least 1 hour before or 4 to 6 hours after taking cholestyramine.

** Mineral Oil or other Substances that May Affect Absorption of Fat**

Clinical
Impact

The use of mineral oil or other substances that may affect absorption of fat may influence the absorption and availability of doxercalciferol.

Intervention

Administer doxercalciferol capsules at least 1 hour before or 4 to 6 hours after taking mineral oil or other substances that may affect absorption of fat.

Key Highlight
  • Cytochrome P450 inhibitors: Formation of the active doxercalciferol moiety may be hindered and may necessitate dosage adjustment. Monitor intact PTH and serum calcium concentrations closely. (7)
  • Enzyme inducers: Formation of the active doxercalciferol moiety may be affected and may necessitate dosage adjustment. Monitor intact PTH and serum calcium concentrations closely. (7)
  • Magnesium-containing products: Combined use may cause hypermagnesemia. Monitor serum magnesium concentrations more frequently and adjust dose as needed. (7)
  • Cholestyramine: May impair absorption of doxercalciferol capsules. Administer doxercalciferol capsules at least 1 hour before or 4 to 6 hours after taking cholestyramine. (7)
  • Mineral oil or other substances that may affect absorption of fat: May impair absorption of doxercalciferol capsules. Administer doxercalciferol capsules at least 1 hour before or 4 to 6 hours after taking substances that may affect absorption.

DOSAGE & ADMINISTRATION SECTION

LOINC: 34068-7Updated: 3/1/2019

2 DOSAGE AND ADMINISTRATION

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)].
Key Highlight
  • 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)

DOSAGE FORMS & STRENGTHS SECTION

LOINC: 43678-2Updated: 3/6/2019

3 DOSAGE FORMS AND STRENGTHS

  • 0.5 mcg – White, opaque, oval shaped soft gelatin capsules. Each capsule is imprinted with**"HP 538"** in black ink.
  • 1 mcg – Beige, opaque, oval shaped soft gelatin capsules. Each capsule is imprinted with**"HP 539"** in black ink.
  • 2.5 mcg – Red, opaque, oval shaped soft gelatin capsules. Each capsule is imprinted with**"HP 540"** in black ink.
Key Highlight
  • Capsules: 0.5 mcg, 1 mcg, and 2.5 mcg (3)

USE IN SPECIFIC POPULATIONS SECTION

LOINC: 43684-0Updated: 3/1/2019

8 USE IN SPECIFIC POPULATIONS

8.1 Pregnancy

Risk Summary

The limited available data with doxercalciferol in pregnant women are insufficient to identify a drug-associated risk for major birth defects, miscarriage or adverse maternal or fetal outcomes. There are risks to the mother and fetus associated with chronic kidney disease in pregnancy [see Clinical Considerations]. In reproduction studies in rats and rabbits administered doxercalciferol during organogenesis at up to 20 mcg/kg/day and 0.1 mcg/kg/day, respectively (approximately 25 times (rats) and less than (rabbits) the maximum recommended human oral dose of 60 mcg/week based on mcg/m2 body surface area), no adverse developmental effects were observed [see Data].

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Clinical Considerations

Disease-associated maternal and/or embryo/fetal risk

Chronic kidney disease in pregnancy increases the risk for maternal hypertension and preeclampsia,

miscarriage, preterm delivery polyhydramnios, stillbirth, and low-birth-weight infants.

Data

Animal data

There were no adverse effects on fetal development when doxercalciferol was administered at doses up to 20 mcg/kg/day in pregnant rats or doses up to 0.1 mcg/kg/day in pregnant rabbits during the period of organogenesis.

8.2 Lactation

Risk Summary

There is no information available on the presence of doxercalciferol in human milk, the effects of the drug on the breastfed infant, or the effects of the drug on milk production. Infants exposed to doxercalciferol through breast milk should be monitored for signs and symptoms of hypercalcemia [see Clinical Considerations].

The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for doxercalciferol and any potential adverse effects on the breastfed child from doxercalciferol or from the underlying maternal condition.

Clinical Considerations

Monitoring of serum calcium in the infant should be considered.

8.4 Pediatric Use

Safety and efficacy of doxercalciferol in pediatric patients have not been established.

8.5 Geriatric Use

Clinical studies of doxercalciferol did not include sufficient numbers of patients 65 years or over to determine whether they respond differently from younger subjects. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic or cardiac function, and of concomitant disease or other drug therapy.

8.6 Hepatic Impairment

Patients with hepatic impairment may not metabolize doxercalciferol appropriately. More frequent monitoring of intact PTH, calcium, and phosphorus levels should be done in patients with hepatic impairment.

OVERDOSAGE SECTION

LOINC: 34088-5Updated: 3/1/2019

10 OVERDOSAGE

Overdosage of doxercalciferol may lead to hypercalcemia, hypercalciuria, and hyperphosphatemia [see Warnings and Precautions (5.1)]. The treatment of acute overdosage should consist of supportive measures and discontinuation of doxercalciferol administration. Serum calcium levels should be measured until normal.

Based on similarities between doxercalciferol and its active metabolite, 1α,25-(OH)2D2, it is expected that doxercalciferol is not removed from the blood by dialysis.

DESCRIPTION SECTION

LOINC: 34089-3Updated: 11/2/2021

11 DESCRIPTION

Doxercalciferol Capsules contains doxercalciferol, which is a synthetic vitamin D2 analog. Doxercalciferol undergoes metabolic activation in vivo to form 1α,25-dihydroxyvitamin D2 (1α,25-(OH)2D2), a naturally occurring, biologically active form of vitamin D2.

Doxercalciferol is a colorless crystalline compound with a calculated molecular weight of 412.66 and a molecular formula of C28H44O2. It is soluble in oils and organic solvents, but is relatively insoluble in water. Chemically, doxercalciferol is (1α,3β,5Z,7E,22E)-9,10-secoergosta-5,7,10(19),22-tetraene-1,3-diol. The structural formula is:

structure

Doxercalciferol capsules are soft gelatin capsules containing 0.5 mcg, 1 mcg, or 2.5 mcg doxercalciferol for oral use. Each capsule also contains butylated hydroxyanisole (BHA), ethanol, and medium-chain triglycerides. The capsule shells contain gelatin, glycerin, iron oxide black and titanium dioxide. In addition, the 0.5 mcg capsule shells contain shellac glaze, the 1 mcg capsule shells contain FD&C Blue No. 1, FD&C Yellow No. 6, shellac and the 2.5 mcg capsule shells contain FD&C Red No. 40 and shellac.

CLINICAL PHARMACOLOGY SECTION

LOINC: 34090-1Updated: 2/28/2019

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

Doxercalciferol is a synthetic vitamin D2 analog that requires metabolic activation to form the active 1α,25-(OH)2D2 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)2D2, 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)2D2 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)2D2 (major metabolite) and 1α,24-dihydroxyvitamin D2 (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)2D2 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)2D2 mean concentrations, presumably due to volume contraction. 1α,25-(OH)2D2 is not removed from blood during hemodialysis.

NONCLINICAL TOXICOLOGY SECTION

LOINC: 43680-8Updated: 3/1/2019

13 NONCLINICAL TOXICOLOGY

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

In a 104-week carcinogenicity study in rats, there was an increased incidence of benign and malignant adrenal pheochromocytomas in both males and females at oral doses of 0.04, 0.13, and 0.39 mcg/kg/day (less than the maximum recommended human oral dose of 60 mcg/week based on mcg/m2 body surface area). This increased incidence of pheochromocytomas in rats may be due to altered calcium homeostasis by doxercalciferol. No evidence of genetic toxicity was observed in an in vitro bacterial mutagenicity assay (Ames test) or a mouse lymphoma gene mutation assay. Doxercalciferol caused structural chromatid and chromosome aberrations in an in vitro human lymphocyte clastogenicity assay with metabolic activation. However, doxercalciferol was negative in an in vivo mouse micronucleus clastogenicity assay.

Doxercalciferol had no effect on male or female fertility in rats at oral doses up to 2.5 mcg/kg/day (approximately 3 times the maximum recommended human oral dose of 60 mcg/week based on mcg/m2 body surface area).

CLINICAL STUDIES SECTION

LOINC: 34092-7Updated: 3/1/2019

14 CLINICAL STUDIES

14.1 Clinical Studies of Doxercalciferol Capsules in Patients with Stage 3

or 4 CKD

The safety and effectiveness of doxercalciferol capsules were evaluated in two clinical studies in 55 patients with Stage 3 or 4 CKD. Eighty-two percent of the patients were male, the average age was 65 years, 51% were Caucasian, 40% African-American, and the average serum intact PTH level at baseline was 195 pg/mL. While levels of 25-(OH) vitamin D were not evaluated at baseline, retrospective assessments of stored serum revealed that the mean ± SD serum 25-(OH) vitamin D was 19 ± 8 ng/mL (range: <5 to 54 ng/mL) in the study population.

After randomization to two groups, eligible patients underwent an 8-week washout period during which no vitamin D derivatives were administered to either group. Subsequently, one group received doxercalciferol capsules and the other placebo during the double-blind period of 24 weeks. The initial dose of doxercalciferol capsules was 1 mcg per day. The dosage of doxercalciferol capsules was adjusted as necessary by the investigator to reduce intact PTH levels to a target of ≥30% below post-washout baseline. The maximum dosage was limited to 3.5 mcg per day. If at any time during the trial intact PTH fell below 15 pg/mL, doxercalciferol capsules were immediately suspended and restarted at a lower dosage the following week.

Decreases in the mean plasma intact PTH from baseline values were calculated using as baseline the average of the last 2 values obtained during the 8-week washout phase. In analyses of pooled data from the two studies, intact PTH levels decreased from baseline by an average of 101 pg/mL in the doxercalciferol capsules group and by 4 pg/mL in the placebo group (p<0.001). Twenty (74%) of 27 subjects in the doxercalciferol capsules group achieved mean plasma intact PTH suppression of ≥30% from baseline for the last four weeks of treatment, whereas two (7%) of the 28 subjects treated with placebo achieved this level of intact PTH suppression.

14.2 Clinical Studies of Doxercalciferol Capsules in Patients with CKD on

Dialysis

The safety and effectiveness of doxercalciferol capsules were evaluated in two double-blind, placebo-controlled, multicenter clinical studies (Study A and Study B) in a total of 138 patients with CKD on hemodialysis. Patients in Study A were an average age of 52 years (range: 22 to 75), were 55% male, and were 58% African-American, 31% Caucasian, and 11% Hispanic, and had been on hemodialysis for an average of 53 months. Patients in Study B were an average of 52 years (range: 27 to 75), were 45% male, and 99% African-American, and 1% Caucasian, and had been on hemodialysis for an average of 56 months. After randomization to two groups, eligible patients underwent an 8-week washout period during which no vitamin D derivatives were administered to either group. Subsequently, all patients received doxercalciferol capsules in an open-label fashion for 16 weeks followed by a double-blind period of 8 weeks during which patients received either doxercalciferol capsules or placebo. The initial dose of doxercalciferol capsules during the open-label phase was 10 mcg after each dialysis session (3 times weekly) for a total of 30 mcg per week. The dosage of doxercalciferol was adjusted as necessary by the investigator to achieve intact PTH levels within 150 pg/mL to 300 pg/mL. The maximum dosage was limited to 20 mcg after each dialysis session (60 mcg/week). If at any time during the trial intact PTH fell below 150 pg/mL, Doxercalciferol was immediately suspended and restarted at a lower dosage the following week. Mean weekly doses during the 16-week open-label period ranged from 15 mcg to 29 mcg in Study A and from 19 mcg to 28 mcg in Study B.

One hundred and six (77%) of the 138 patients who were treated with doxercalciferol capsules during the 16- week open-label phase achieved intact PTH levels ≤300 pg/mL. Ninety-four (68%) of these patients exhibited plasma intact PTH levels ≤300 pg/mL on at least 3 occasions. Eighty-seven (63%) patients had plasma intact PTH levels <150 pg/mL on at least one occasion during the open-label phase of study participation.

Decreases in plasma intact PTH from baseline values were calculated using as baseline the average of the last 3 values obtained during the 8-week washout phase and are displayed in Table 5.

Table 5: Intact PTH Summary Data for Patients with CKD on Dialysis Receiving Doxercalciferol Capsules in Studies A and B
  • All subjects; last value carried to discontinuation.

NA = not applicable

** Intact PTH (pg/mL)**

** means** ±** SD (n)***
** p-value vs Baseline**
** p-value vs Placebo**

** Doxercalciferol Capsules**

** Placebo**

Study A

Baseline

797.2 ± 443.8 (30)
NA
0.97

847.1 ± 765.5 (32)

Week 16
(open-label)

384.3 ± 397.8 (24)
<0.001
0.72

526.5 ± 872.2 (29)
<0.001

Week 24
(double-blind)

404.4 ± 262.9 (21)
<0.001
0.008

672.6 ± 356.9 (24)
0.70

Study B

Baseline

973.9 ± 567.0 (41)
NA
0.81

990.4 ± 488.3 (35)

Week 16
(open-label)

476.1 ± 444.5 (37)
<0.001
0.91

485.9 ± 443.4 (32)
<0.001

Week 24
(double-blind)

459.8 ± 443.0 (35)
<0.001
<0.001

871.9 ± 623.6 (30)
<0.065

Doxercalciferol capsules treatment resulted in a statistically significant reduction from baseline in mean intact PTH levels during the 16-week open- label treatment period in more than 94% of the 138 treated patients. During the double-blind period (weeks 17 to 24), the reduction in mean intact PTH levels was maintained in the doxercalciferol capsules treatment group compared to a return to near baseline in the placebo group.

HOW SUPPLIED SECTION

LOINC: 34069-5Updated: 3/1/2019

16 HOW SUPPLIED/STORAGE AND HANDLING

How Supplied

Doxercalciferol capsules are oval, soft gelatin capsules supplied as follows.

** Strength**

** Capsule Color**

** Imprint Code**

** Package Size**

** NDC**

0.5 mcg

White, Opaque

HP 538

Bottle of 50 capsules

23155-538-25

1 mcg

Beige, Opaque

HP 539

Bottle of 50 capsules

23155-539-25

2.5 mcg

Red, Opaque

HP 540

Bottle of 50 capsules

23155-540-25

Storage and Handling

Store at 25°C (77°F); excursions permitted to 15° to 30°C (59° to 86°F)

[see USP Controlled Room Temperature.]

INFORMATION FOR PATIENTS SECTION

LOINC: 34076-0Updated: 11/2/2021

17 PATIENT COUNSELING INFORMATION

Hypercalcemia

Advise patients to contact a health care provider if they develop symptoms of elevated calcium (e.g. feeling tired, difficulty thinking clearly, loss of appetite, nausea, vomiting, constipation, increased thirst, increased urination and weight loss) [see Warnings and Precautions (5.1)].

Hypersensitivity

Inform patients that hypersensitivity reactions can occur with doxercalciferol [see Warnings and Precautions (5.3)].

Monitoring

Inform patients that they will need routine monitoring of laboratory parameters such as calcium and intact PTH while receiving doxercalciferol. Inform patients that more frequent monitoring is necessary during the initiation of therapy, following dose changes or when potentially interacting medications are started or discontinued [see Dosage and Administration (2), Drug Interactions (7)].

Drug Interactions

Advise patients to inform their physician of all medications, including prescription and nonprescription drugs, and supplements they are taking. Advise patients to also inform their physician that they are receiving doxercalciferol if a new medication is prescribed [see Drug Interactions (7)].

Distributed by:

Avet Pharmaceuticals Inc.

East Brunswick, NJ 08816

1.866.901.DRUG (3784)

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51U000000118US04

Revised: 09/2020

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Doxercalciferol - FDA Drug Approval Details