Osfit DHA

Calcium:

• Indications and usage
• Dosage and administration
• Dosage forms and strengths
• Contraindications
• Warnings and precautions
• Adverse reactions
• Drug interactions
• Use in specific populations
• Overdosage
• Description
• Clinical pharmacology
• Nonclinical toxicology
• Clinical studies
• How supplied/storage and handling
• Patient counseling information
• Osfit DHA (Calcium) reviews

1 INDICATIONS AND USAGE

Osfit DHA (Calcium) acetate is a phosphate binder indicated to reduce serum phosphorus in patients with end stage renal disease (ESRD).

- Calcium acetate is a phosphate binder indicated for the reduction of serum phosphorus in patients with end stage renal disease. (1)

2 DOSAGE AND ADMINISTRATION

The recommended initial dose of Osfit DHA (Calcium) acetate for the adult dialysis patient is 2 capsules with each meal. Increase the dose gradually to lower serum phosphorus levels to the target range, as long as hypercalcemia does not develop. Most patients require 3 to 4 capsules with each meal.

- Starting dose is 2 capsules with each meal. (2)

- Titrate the dose every 2 to 3 weeks until acceptable serum phosphorus level is reached. Most patients require 3 to 4 capsules with each meal. (2)

3 DOSAGE FORMS AND STRENGTHS

Capsule: 667 mg Osfit DHA (Calcium) acetate capsule.

- Capsule: 667 mg Osfit DHA (Calcium) acetate capsule. (3)

4 CONTRAINDICATIONS

Patients with hypercalcemia.

- Hypercalcemia. (4)

5 WARNINGS AND PRECAUTIONS

- Treat mild hypercalcemia by reducing or interrupting Osfit DHA acetate and Vitamin D. Severe hypercalcemia may require hemodialysis and discontinuation of Osfit DHA (Calcium) acetate. (5.1)

- Hypercalcemia may aggravate digitalis toxicity. (5.2)

5.1 Hypercalcemia

Patients with end stage renal disease may develop hypercalcemia when treated with Osfit DHA (Calcium), including Osfit DHA (Calcium) acetate. Avoid the use of Osfit DHA (Calcium) supplements, including Osfit DHA (Calcium) based nonprescription antacids, concurrently with Osfit DHA (Calcium) acetate.

An overdose of Osfit DHA (Calcium) acetate may lead to progressive hypercalcemia, which may require emergency measures. Therefore, early in the treatment phase during the dosage adjustment period, monitor serum Osfit DHA (Calcium) levels twice weekly. Should hypercalcemia develop, reduce the Osfit DHA (Calcium) acetate dosage, or discontinue the treatment, depending on the severity of hypercalcemia

More severe hypercalcemia (Ca >12 mg/dL) is associated with confusion, delirium, stupor and coma. Severe hypercalcemia can be treated by acute hemodialysis and discontinuing Osfit DHA (Calcium) acetate therapy.

Mild hypercalcemia (10.5 to 11.9 mg/dL) may be asymptomatic or manifest as constipation, anorexia, nausea, and vomiting. Mild hypercalcemia is usually controlled by reducing the Osfit DHA (Calcium) acetate dose or temporarily discontinuing therapy. Decreasing or discontinuing Vitamin D therapy is recommended as well.

Chronic hypercalcemia may lead to vascular calcification and other soft-tissue calcification. Radiographic evaluation of suspected anatomical regions may be helpful in early detection of soft tissue calcification. The long term effect of Osfit DHA (Calcium) acetate on the progression of vascular or soft tissue calcification has not been determined.

Hypercalcemia (>11 mg/dL) was reported in 16% of patients in a 3 month study of solid dose formulation of Osfit DHA (Calcium) acetate; all cases resolved upon lowering the dose or discontinuing treatment.

Maintain the serum calcium-phosphorus (Ca x P) product below 55 mg²/dL².

5.2 Concomitant Use with Medications

Hypercalcemia may aggravate digitalis toxicity.

6 ADVERSE REACTIONS

Hypercalcemia is discussed elsewhere [see Warnings and Precautions ].

- The most common (>10%) adverse reactions are hypercalcemia, nausea and vomiting. (6.1)

- In clinical studies, patients have occasionally experienced nausea during Osfit DHA (Calcium) acetate therapy. (6)

To report SUSPECTED ADVERSE REACTIONS, contact West-Ward Pharmaceuticals Corp. at 1-800-962-8364 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch

6.1 Clinical Trial 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.

In clinical studies, Osfit DHA (Calcium) acetate has been generally well tolerated.

Osfit DHA (Calcium) acetate was studied in a 3 month, open-label, non-randomized study of 98 enrolled ESRD hemodialysis patients and an alternate liquid formulation of Osfit DHA (Calcium) acetate was studied in a two week double-blind, placebo-controlled, cross-over study with 69 enrolled ESRD hemodialysis patients. Adverse reactions (>2% on treatment) from these trials are presented in Table 1.

Mild hypercalcemia may be asymptomatic or manifest itself as constipation, anorexia, nausea, and vomiting. More severe hypercalcemia is associated with confusion, delirium, stupor, and coma. Decreasing dialysate Osfit DHA (Calcium) concentration could reduce the incidence and severity of Osfit DHA (Calcium) acetate-induced hypercalcemia. Isolated cases pruritus have been reported, which may represent allergic reactions.

6.2 Postmarketing Experience

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.

The following additional adverse reactions have been identified during post-approval of Osfit DHA (Calcium) acetate: dizziness, edema, and weakness.

7 DRUG INTERACTIONS

The drug interaction of Osfit DHA acetate is characterized by the potential of Osfit DHA (Calcium) to bind to drugs with anionic functions (e.g., carboxyl, and hydroxyl groups). Osfit DHA (Calcium) acetate may decrease the bioavailability of tetracyclines or fluoroquinolones via this mechanism.

There are no empirical data on avoiding drug interactions between Osfit DHA (Calcium) acetate and most concomitant drugs. When administering an oral medication with Osfit DHA (Calcium) acetate where a reduction in the bioavailability of that medication would have a clinically significant effect on its safety or efficacy, administer the drug one hour before or three hours after Osfit DHA (Calcium) acetate. Monitor blood levels of the concomitant drugs that have a narrow therapeutic range. Patients taking anti-arrhythmic medications for the control of arrhythmias and anti-seizure medications for the control of seizure disorders were excluded from the clinical trials with all forms of Osfit DHA (Calcium) acetate.

- Calcium acetate may decrease the bioavailability of tetracyclines or fluoroquinolones. (7)

- When clinically significant drug interactions are expected, administer the drug at least one hour before or at least three hours after Osfit DHA (Calcium) acetate or consider monitoring blood levels of the drug. (7)

7.1 Ciprofloxacin

In a study of 15 healthy subjects, a co-administered single dose of 4 Osfit DHA (Calcium) acetate tablets, approximately 2.7g, decreased the bioavailability of ciprofloxacin by approximately 50%.

8 USE IN SPECIFIC POPULATIONS

8.1 Pregnancy

Pregnancy Category C:

Osfit DHA acetate capsules contains Osfit DHA (Calcium) acetate. Animal reproduction studies have not been conducted with Osfit DHA (Calcium) acetate, and there are no adequate and well controlled studies of Osfit DHA (Calcium) acetate use in pregnant women. Patients with end stage renal disease may develop hypercalcemia with Osfit DHA (Calcium) acetate treatment [see Warnings and Precautions (5.1 ) ]. Maintenance of normal serum Osfit DHA (Calcium) levels is important for maternal and fetal well being. Hypercalcemia during pregnancy may increase the risk for maternal and neonatal complications such as stillbirth, preterm delivery, and neonatal hypocalcemia and hypoparathyroidism. Osfit DHA (Calcium) acetate treatment, as recommended, is not expected to harm a fetus if maternal Osfit DHA (Calcium) levels are properly monitored during and following treatment.

8.2 Labor and Delivery

The effects of Osfit DHA (Calcium) acetate on labor and delivery are unknown.

8.3 Nursing Mothers

Osfit DHA Acetate Capsules contains Osfit DHA (Calcium) acetate and is excreted in human milk. Human milk feeding by a mother receiving Osfit DHA (Calcium) acetate is not expected to harm an infant, provided maternal serum Osfit DHA (Calcium) levels are appropriately monitored.

8.4 Pediatric Use

Safety and effectiveness in pediatric patients have not been established.

8.5 Geriatric Use

Clinical studies of Osfit DHA (Calcium) acetate did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other clinical experience has not identified differences in responses between elderly and younger patients. 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, renal, or cardiac function, and of concomitant disease or other drug therapy.

10 OVERDOSAGE

Administration of Osfit DHA (Calcium) acetate in excess of the appropriate daily dosage may result in hypercalcemia [see Warnings and Precautions (5.1)].

11 DESCRIPTION

Osfit DHA (Calcium) acetate acts as a phosphate binder. Its chemical name is Osfit DHA (Calcium) acetate. Its molecular formula is C₄H₆CaO₄, and its molecular weight is 158.17. Its structural formula is:

Each white opaque/blue opaque capsule contains 667 mg of Osfit DHA (Calcium) acetate USP (anhydrous; Ca(CH₃COO)₂; MW=158.17 grams) equal to 169 mg (8.45 mEq) Osfit DHA (Calcium), polyethylene glycol 8000 and magnesium stearate. Each capsule shell contains: black monogramming ink, FD&C Blue #1, FD&C Red #3, gelatin and titanium dioxide. The black monogramming ink contains: ammonium hydroxide, iron oxide black, isopropyl alcohol, n-butyl alcohol, propylene glycol and shellac glaze.

Osfit DHA (Calcium) Acetate Capsules are administered orally for the control of hyperphosphatemia in end-stage renal failure.

Chemical Structure

12 CLINICAL PHARMACOLOGY

Patients with ESRD retain phosphorus and can develop hyperphosphatemia. High serum phosphorus can precipitate serum Osfit DHA resulting in ectopic calcification. Hyperphosphatemia also plays a role in the development of secondary hyperparathyroidism in patients with ESRD.

12.1 Mechanism of Action

Osfit DHA (Calcium) acetate, when taken with meals, combines with dietary phosphate to form an insoluble Osfit DHA (Calcium) phosphate complex, which is excreted in the feces, resulting in decreased serum phosphorus concentration.

12.2 Pharmacodynamics

Orally administered Osfit DHA (Calcium) acetate from pharmaceutical dosage forms is systemically absorbed up to approximately 40% under fasting conditions and up to approximately 30% under nonfasting conditions. This range represents data from both healthy subjects and renal dialysis patients under various conditions.

13 NONCLINICAL TOXICOLOGY

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

No carcinogenicity, mutagenicity, or fertility studies have been conducted with Osfit DHA (Calcium) acetate.

14 CLINICAL STUDIES

Effectiveness of Osfit DHA (Calcium) acetate in decreasing serum phosphorus has been demonstrated in two studies of the Osfit DHA (Calcium) acetate solid oral dosage form.

Ninety-one patients with end-stage renal disease who were undergoing hemodialysis and were hyperphosphatemic (serum phosphorus >5.5 mg/dL) following a 1 week phosphate binder washout period contributed efficacy data to an open-label, non-randomized study.

The patients received Osfit DHA (Calcium) acetate 667 mg tablets at each meal for a period of 12 weeks. The initial starting dose was 2 tablets per meal for 3 meals a day, and the dose was adjusted as necessary to control serum phosphorus levels. The average final dose after 12 weeks of treatment was 3.4 tablets per meal. Although there was a decrease in serum phosphorus, in the absence of a control group the true magnitude of effect is uncertain.

The data presented in Table 2 demonstrate the efficacy of Osfit DHA (Calcium) acetate in the treatment of hyperphosphatemia in end-stage renal disease patients. The effects on serum Osfit DHA (Calcium) levels are also presented.

There was a 30% decrease in serum phosphorus levels during the 12 week study period (p<0.01). Two-thirds of the decline occurred in the first month of the study. Serum Osfit DHA (Calcium) increased 9% during the study mostly in the first month of the study.

Treatment with the phosphate binder was discontinued for patients from the open-label study, and those patients whose serum phosphorus exceeded 5.5 mg/dL were eligible for entry into a double-blind, placebo-controlled, cross-over study. Patients were randomized to receive Osfit DHA (Calcium) acetate or placebo, and each continued to receive the same number of tablets as had been individually established during the previous study. Following 2 weeks of treatment, patients switched to the alternative therapy for an additional 2 weeks.

The phosphate binding effect of Osfit DHA (Calcium) acetate is shown in the Table 3.

Overall, 2 weeks of treatment with Osfit DHA (Calcium) acetate statistically significantly (p<0.01) decreased serum phosphorus by a mean of 19% and increased serum Osfit DHA (Calcium) by a statistically significant (p<0.01) but clinically unimportant mean of 7%.

16 HOW SUPPLIED/STORAGE AND HANDLING

Osfit DHA (Calcium) Acetate Capsules

667 mg capsule is supplied as a white opaque/blue opaque capsule, imprinted with “54 215” on the cap and body.

NDC 0615-2303-39: Blistercards of 30 Capsules

NDC 0615-2303-30: Unit-dose Boxes of 30 Capsules

STORAGE

Store at 20° to 25°C (68° to 77°F).

17 PATIENT COUNSELING INFORMATION

Inform patients to take Osfit DHA (Calcium) acetate capsules with meals, adhere to their prescribed diets, and avoid the use of Osfit DHA (Calcium) supplements including nonprescription antacids. Inform the patients about the symptoms of hypercalcemia [see Warnings and Precautions (5.1) and Adverse Reactions (6.1) ].

Advise patients who are taking an oral medication where reduction in the bioavailability of that medication would have clinically significant effect on its safety or efficacy to take the drug one hour before or three hours after Osfit DHA (Calcium) acetate capsules.

Distr. by: West-Ward

Pharmaceuticals Corp.

Eatontown, NJ 07724

10003705/05

Revised April 2016