Rapamune (Sirolimus) - Indications and Dosage

INDICATIONS AND USAGE

Prophylaxis of Organ Rejection in Renal Transplantation

Rapamune (sirolimus) is indicated for the prophylaxis of organ rejection in patients aged 13 years or older receiving renal transplants. Therapeutic drug monitoring is recommended for all patients receiving Rapamune [see Dosage and Administration (2.3), Warnings and Precautions (5.14) ].

In patients at low- to moderate-immunologic risk, it is recommended that Rapamune be used initially in a regimen with cyclosporine and corticosteroids; cyclosporine should be withdrawn 2 to 4 months after transplantation [see Dosage and Administration (2.2) ].

In patients at high-immunologic risk (defined as Black recipients and/or repeat renal transplant recipients who lost a previous allograft for immunologic reason and/or patients with high panel-reactive antibodies [PRA; peak PRA level > 80%]), it is recommended that Rapamune be used in combination with cyclosporine and corticosteroids for the first year following transplantation [see Dosage and Administration (2.2), Clinical Studies (14.2) ].

Limitations of Use

Cyclosporine withdrawal has not been studied in patients with Banff Grade 3 acute rejection or vascular rejection prior to cyclosporine withdrawal, those who are dialysis-dependent, those with serum creatinine > 4.5 mg/dL, Black patients, patients of multi-organ transplants, secondary transplants, or those with high levels of panel-reactive antibodies [see Clinical Studies (14.2) ].

In patients at high-immunologic risk, the safety and efficacy of Rapamune used in combination with cyclosporine and corticosteroids has not been studied beyond one year; therefore after the first 12 months following transplantation, any adjustments to the immunosuppressive regimen should be considered on the basis of the clinical status of the patient [see Clinical Studies (14.3) ].

In pediatric patients, the safety and efficacy of Rapamune have not been established in patients < 13 years old, or in pediatric (< 18 years) renal transplant patients considered at high-immunologic risk [see Adverse Reactions (6.5), Clinical Studies (14.5) ]. The safety and efficacy of de novo use of Rapamune without cyclosporine have not been established in renal transplant patients [see Warnings and Precautions (5.11) ].

The safety and efficacy of conversion from calcineurin inhibitors to Rapamune in maintenance renal transplant patients have not been established [see Clinical Studies (14.2) ].

DOSAGE AND ADMINISTRATION

Rapamune is to be administered orally once daily, consistently with or without food [ see Dosage and Administration (2.4), Clinical Pharmacology (12.3) ].

Tablets should not be crushed, chewed or split. Patients unable to take the tablets should be prescribed the solution and instructed in its use.

The initial dose of Rapamune should be administered as soon as possible after transplantation. It is recommended that Rapamune be taken 4 hours after administration of cyclosporine oral solution (MODIFIED) and or/cyclosporine capsules (MODIFIED) [see Drug Interactions (7.2) ].

Frequent Rapamune dose adjustments based on non-steady-state sirolimus concentrations can lead to overdosing or underdosing because sirolimus has a long half-life. Once Rapamune maintenance dose is adjusted, patients should continue on the new maintenance dose for at least 7 to 14 days before further dosage adjustment with concentration monitoring. In most patients, dose adjustments can be based on simple proportion: new Rapamune dose = current dose x (target concentration/current concentration). A loading dose should be considered in addition to a new maintenance dose when it is necessary to increase sirolimus trough concentrations: Rapamune loading dose = 3 x (new maintenance dose - current maintenance dose). The maximum Rapamune dose administered on any day should not exceed 40 mg. If an estimated daily dose exceeds 40 mg due to the addition of a loading dose, the loading dose should be administered over 2 days. Sirolimus trough concentrations should be monitored at least 3 to 4 days after a loading dose(s).

Two milligrams (2 mg) of Rapamune Oral Solution have been demonstrated to be clinically equivalent to 2 mg Rapamune Tablets; hence, are interchangeable on a mg-to-mg basis. However, it is not known if higher doses of Rapamune Oral Solution are clinically equivalent to higher doses of Rapamune Tablets on a mg‑to‑mg basis [see Clinical Pharmacology (12.3) ].

Patients at Low- to Moderate-Immunologic Risk

Rapamune and Cyclosporine Combination Therapy

For de novo renal transplant patients, it is recommended that Rapamune Oral Solution and Tablets be used initially in a regimen with cyclosporine and corticosteroids. A loading dose of Rapamune equivalent to 3 times the maintenance dose should be given, i.e. a daily maintenance dose of 2 mg should be preceded with a loading dose of 6 mg. Therapeutic drug monitoring should be used to maintain sirolimus drug concentrations within the target-range [see Dosage and Administration (2.3) ].

Rapamune Following Cyclosporine Withdrawal

At 2 to 4 months following transplantation, cyclosporine should be progressively discontinued over 4 to 8 weeks, and the Rapamune dose should be adjusted to obtain sirolimus whole blood trough concentrations within the target-range [see Dosage and Administration (2.3) ]. Because cyclosporine inhibits the metabolism and transport of sirolimus, sirolimus concentrations may decrease when cyclosporine is discontinued, unless the Rapamune dose is increased [see Clinical Pharmacology (12.3) ].

Patients at High-Immunologic Risk

In patients with high-immunologic risk, it is recommended that Rapamune be used in combination with cyclosporine and corticosteroids for the first 12 months following transplantation [see Clinical Studies (14.2) ]. The safety and efficacy of this combination in high-immunologic risk patients has not been studied beyond the first 12 months. Therefore, after the first 12 months following transplantation, any adjustments to the immunosuppressive regimen should be considered on the basis of the clinical status of the patient.

For patients receiving Rapamune with cyclosporine, Rapamune therapy should be initiated with a loading dose of up to 15 mg on day 1 post-transplantation. Beginning on day 2, an initial maintenance dose of 5 mg/day should be given. A trough level should be obtained between days 5 and 7, and the daily dose of Rapamune should thereafter be adjusted [see Dosage and Administration (2.3) ].

The starting dose of cyclosporine should be up to 7 mg/kg/day in divided doses and the dose should subsequently be adjusted to achieve target whole blood trough concentrations [see Dosage and Administration (2.3) ]. Prednisone should be administered at a minimum of 5 mg/day.

Antibody induction therapy may be used.

Therapeutic Drug Monitoring

Monitoring of sirolimus trough concentrations is recommended for all patients, especially in those patients likely to have altered drug metabolism, in patients≥ 13 years who weigh less than 40 kg, in patients with hepatic impairment, when a change in the Rapamune dosage form is made, and during concurrent administration of strong CYP3A4 inducers and inhibitors [see Drug Interactions (7) ].

Therapeutic drug monitoring should not be the sole basis for adjusting Rapamune therapy. Careful attention should be made to clinical signs/symptoms, tissue biopsy findings, and laboratory parameters.

When used in combination with cyclosporine, sirolimus trough concentrations should be maintained within the target-range [see Clinical Studies (14), Clinical Pharmacology (12.3) ]. Following cyclosporine withdrawal in transplant patients at low- to moderate-immunologic risk, the target sirolimus trough concentrations should be 16 to 24 ng/mL for the first year following transplantation. Thereafter, the target sirolimus concentrations should be 12 to 20 ng/mL.

The above recommended 24-hour trough concentration ranges for sirolimus are based on chromatographic methods. On average, chromatographic methods (HPLC UV or LC/MS/MS) yield results that are approximately 20% lower than the immunoassay for whole blood concentration determinations. Currently in clinical practice, sirolimus whole blood concentrations are being measured by both chromatographic and immunoassay methodologies. Because the measured sirolimus whole blood concentrations depend on the type of assay used, the concentrations obtained by these different methodologies are not interchangeable [see Warnings and Precautions (5.14), Clinical Pharmacology (12.3) ]. Adjustments to the targeted range should be made according to the assay utilized to determine sirolimus trough concentrations. A discussion of different assay methods is contained in Clinical Therapeutics, Volume 22, Supplement B, April 2000 [see References (15) ].

Patients with Low Body Weight

The initial dosage in patients ≥ 13 years who weigh less than 40 kg should be adjusted, based on body surface area, to 1 mg/m²/day. The loading dose should be 3 mg/m².

Patients with Hepatic Impairment

It is recommended that the maintenance dose of Rapamune be reduced by approximately one third in patients with mild or moderate hepatic impairment and by approximately one half in patients with severe hepatic impairment. It is not necessary to modify the Rapamune loading dose [see Clinical Pharmacology (12.3) ].

Patients with Renal Impairment

Dosage adjustment is not needed in patients with impaired renal function [see Use in Specific Populations (8.7) ].

Instructions for Dilution and Administration of Rapamune Oral Solution

The amber oral dose syringe should be used to withdraw the prescribed amount of Rapamune Oral Solution from the bottle. Empty the correct amount of Rapamune from the syringe into only a glass or plastic container holding at least two (2) ounces (1/4 cup, 60 mL) of water or orange juice. No other liquids, including grapefruit juice, should be used for dilution [see Drug Interactions (7.3), Clinical Pharmacology (12.3) ]. Stir vigorously and drink at once. Refill the container with an additional volume [minimum of four (4) ounces (1/2 cup, 120 mL)] of water or orange juice, stir vigorously, and drink at once.

Rapamune Oral Solution contains polysorbate 80, which is known to increase the rate of di‑(2‑ethylhexyl) phthalate (DEHP) extraction from polyvinyl chloride (PVC). This should be considered during the preparation and administration of Rapamune Oral Solution. It is important that these recommendations be followed closely.

DOSAGE FORMS AND STRENGTHS

Rapamune Oral Solution

• 60 mg per 60 mL in amber glass bottle.

HOW SUPPLIED/STORAGE AND HANDLING

Since Rapamune is not absorbed through the skin, there are no special precautions. However, if direct contact with the skin or mucous membranes occurs, wash thoroughly with soap and water; rinse eyes with plain water.

Rapamune Oral Solution

Each Rapamune Oral Solution carton, NDC 0008-1030-06, contains one 2 oz (60 mL fill) amber glass bottle of sirolimus (concentration of 1 mg/mL), one oral syringe adapter for fitting into the neck of the bottle, sufficient disposable amber oral syringes and caps for daily dosing, and a carrying case.

Rapamune Oral Solution bottles should be stored protected from light and refrigerated at 2°C to 8°C (36°F to 46°F). Once the bottle is opened, the contents should be used within one month. If necessary, the patient may store the bottles at room temperatures up to 25°C (77°F) for a short period of time (e.g., not more than 15 days for the bottles).

An amber syringe and cap are provided for dosing, and the product may be kept in the syringe for a maximum of 24 hours at room temperatures up to 25°C (77°F) or refrigerated at 2°C to 8°C (36°F to 46°F). The syringe should be discarded after one use. After dilution, the preparation should be used immediately.

Rapamune Oral Solution provided in bottles may develop a slight haze when refrigerated. If such a haze occurs, allow the product to stand at room temperature and shake gently until the haze disappears. The presence of this haze does not affect the quality of the product.

Rapamune Tablets

Rapamune Tablets are available as follows:

• NDC 0008-1041-05, 1 mg, white, triangular-shaped tablets marked“RAPAMUNE 1 mg” on one side; bottle containing 100 tablets.
• NDC 0008-1041-10, 1 mg, white, triangular-shaped tablets marked“RAPAMUNE 1 mg” on one side; in Redipak^® cartons of 100 tablets (10 blister cards of 10 tablets each).
• NDC 0008-1042-05, 2 mg, yellow-to-beige triangular-shaped tablets marked “RAPAMUNE 2 mg” on one side; bottle containing 100 tablets.

Rapamune Tablets should be stored at 20° to 25°C [USP Controlled Room Temperature] (68° to 77°F). Use cartons to protect blister cards and strips from light. Dispense in a tight, light-resistant container as defined in the USP.