Sirolimus Tablets and Cyclosporine Combination Therapy
For
de novo renal transplant patients, it is recommended that sirolimus oral solution and tablets be used initially in a regimen with cyclosporine and corticosteroids. A loading dose of sirolimus tablets 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 (2.5)].
Sirolimus Tablets Following Cyclosporine Withdrawal
At 2 to 4 months following transplantation, cyclosporine should be progressively discontinued over 4 to 8 weeks, and the sirolimus tablets dose should be adjusted to obtain sirolimus whole blood trough concentrations within the target-range [
see
Dosage and Administration (2.5)]. Because cyclosporine inhibits the metabolism and transport of sirolimus, sirolimus concentrations may decrease when cyclosporine is discontinued, unless the sirolimus tablets dose is increased [
see
Clinical Pharmacology (12.3)].
Increased Serum Cholesterol and Triglycerides
The use of sirolimus in renal transplant patients was associated with increased serum cholesterol and triglycerides that may require treatment.
In Studies 1 and 2, in
de novo renal transplant patients who began the study with fasting, total serum cholesterol <200 mg/dL or fasting, total serum triglycerides <200 mg/dL, there was an increased incidence of hypercholesterolemia (fasting serum cholesterol >240 mg/dL) or hypertriglyceridemia (fasting serum triglycerides >500 mg/dL), respectively, in patients receiving both sirolimus 2 mg and sirolimus 5 mg compared with azathioprine and placebo controls.
Treatment of new-onset hypercholesterolemia with lipid-lowering agents was required in 42 to 52% of patients enrolled in the sirolimus arms of Studies 1 and 2 compared with 16% of patients in the placebo arm and 22% of patients in the azathioprine arm. In other sirolimus renal transplant studies, up to 90% of patients required treatment for hyperlipidemia and hypercholesterolemia with anti-lipid therapy (e.g., statins, fibrates). Despite anti-lipid management, up to 50% of patients had fasting serum cholesterol levels >240 mg/dL and triglycerides above recommended target levels [
see
Warnings and Precautions (5.7)].
Abnormal Healing
Abnormal healing events following transplant surgery include fascial dehiscence, incisional hernia, and anastomosis disruption (e.g., wound, vascular, airway, ureteral, biliary).
Malignancies
Table 2 below summarizes the incidence of malignancies in the two controlled trials (Studies 1 and 2) for the prevention of acute rejection [
see
Clinical Studies (14.1)].
At 24 months (Study 1) and 36 months (Study 2) post-transplant, there were no significant differences among treatment groups.
TABLE 2: INCIDENCE (%) OF MALIGNANCIES IN STUDY 1 (24 MONTHS) AND STUDY 2 (36 MONTHS) POST-TRANSPLANT
,| Malignancy | Sirolimus Oral Solution 2 mg/day | Sirolimus Oral Solution 5 mg/day | Azathioprine 2 to 3 mg/kg/day | Placebo |
|---|
Study 1 (n = 284) | Study 2 (n = 227) | Study 1 (n = 274) | Study 2 (n = 219) | Study 1 (n = 161) | Study 2 (n = 130) |
|---|
Lymphoma/lymphoproliferative disease | 0.7 | 1.8 | 1.1 | 3.2 | 0.6 | 0.8 |
Skin Carcinoma | | | | | | |
Any Squamous Cell
| 0.4 | 2.7 | 2.2 | 0.9 | 3.8 | 3.0 |
Any Basal Cell
| 0.7 | 2.2 | 1.5 | 1.8 | 2.5 | 5.3 |
Melanoma | 0.0 | 0.4 | 0.0 | 1.4 | 0.0 | 0.0 |
Miscellaneous/Not Specified | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.8 |
Total | 1.1 | 4.4 | 3.3 | 4.1 | 4.3 | 7.7 |
Other Malignancy | 1.1 | 2.2 | 1.5 | 1.4 | 0.6 | 2.3 |
Malignancies
The incidence of malignancies in Study 3 [
see
Clinical Studies (14.2)] is presented in Table 3.
In Study 3, the incidence of lymphoma/lymphoproliferative disease was similar in all treatment groups. The overall incidence of malignancy was higher in patients receiving sirolimus plus cyclosporine compared with patients who had cyclosporine withdrawn. Conclusions regarding these differences in the incidence of malignancy could not be made because Study 3 was not designed to consider malignancy risk factors or systematically screen subjects for malignancy. In addition, more patients in the sirolimus with cyclosporine group had a pretransplantation history of skin carcinoma.
TABLE 3: INCIDENCE (%) OF MALIGNANCIES IN STUDY 3 (CYCLOSPORINE WITHDRAWAL STUDY) AT 36 MONTHS POST-TRANSPLANT
,| Malignancy | Nonrandomized (n = 95) | Sirolimus with Cyclosporine Therapy (n = 215) | Sirolimus Following Cyclosporine Withdrawal (n = 215) |
|---|
Lymphoma/lymphoproliferative disease | 1.1 | 1.4 | 0.5 |
Skin Carcinoma | | | |
Any Squamous Cell
| 3.2 | 3.3 | 2.3 |
Any Basal Cell
| 3.2 | 6.5 | 2.3 |
Melanoma | 0.0 | 0.5 | 0.0 |
Miscellaneous/Not Specified | 1.1 | 0.9 | 0.0 |
Total | 4.2 | 7.9 | 3.7 |
Other Malignancy | 3.2 | 3.3 | 1.9 |
Absorption
Following administration of sirolimus oral solution, the mean times to peak concentration (t
max) of sirolimus are approximately 1 hour and 2 hours in healthy subjects and renal transplant patients, respectively. The systemic availability of sirolimus is low, and was estimated to be approximately 14% after the administration of sirolimus oral solution. In healthy subjects, the mean bioavailability of sirolimus after administration of the tablet is approximately 27% higher relative to the solution. Sirolimus tablets are not bioequivalent to the solution; however, clinical equivalence has been demonstrated at the 2 mg dose level. Sirolimus concentrations, following the administration of sirolimus oral solution to stable renal transplant patients, are dose-proportional between 3 and 12 mg/m
2.
Food Effects
To minimize variability in sirolimus concentrations, both sirolimus oral solution and tablets should be taken consistently with or without food [
see
Dosage and Administration (2)]. In healthy subjects, a high-fat meal (861.8 kcal, 54.9% kcal from fat) increased the mean total exposure (AUC) of sirolimus by 23 to 35%, compared with fasting. The effect of food on the mean sirolimus C
max was inconsistent depending on the sirolimus dosage form evaluated.
Distribution
The mean (± SD) blood-to-plasma ratio of sirolimus was 36 ± 18 in stable renal allograft patients, indicating that sirolimus is extensively partitioned into formed blood elements. The mean volume of distribution (Vss/F) of sirolimus is 12 ± 8 L/kg. Sirolimus is extensively bound (approximately 92%) to human plasma proteins, mainly serum albumin (97%), α
1-acid glycoprotein, and lipoproteins.
Metabolism
Sirolimus is a substrate for both CYP3A4 and P-gp. Sirolimus is extensively metabolized in the intestinal wall and liver and undergoes counter-transport from enterocytes of the small intestine into the gut lumen. Inhibitors of CYP3A4 and P-gp increase sirolimus concentrations. Inducers of CYP3A4 and P-gp decrease sirolimus concentrations [
see
Warnings and Precautions (5.17) and
Drug Interactions (7)]. Sirolimus is extensively metabolized by O-demethylation and/or hydroxylation. Seven (7) major metabolites, including hydroxy, demethyl, and hydroxydemethyl, are identifiable in whole blood. Some of these metabolites are also detectable in plasma, fecal, and urine samples. Sirolimus is the major component in human whole blood and contributes to more than 90% of the immunosuppressive activity.
Excretion
After a single dose of [
14C] sirolimus oral solution in healthy volunteers, the majority (91%) of radioactivity was recovered from the feces, and only a minor amount (2.2%) was excreted in urine. The mean ± SD terminal elimination half life (t
½) of sirolimus after multiple dosing in stable renal transplant patients was estimated to be about 62 ± 16 hours.
Sirolimus Concentrations (Chromatographic Equivalent) Observed in Phase 3 Clinical Studies
The following sirolimus concentrations (chromatographic equivalent) were observed in phase 3 clinical studies for prophylaxis of organ rejection in
de novo renal transplant patients [
see
Clinical Studies (14)].
TABLE 5: SIROLIMUS WHOLE BLOOD TROUGH CONCENTRATIONS OBSERVED IN RENAL TRANSPLANT PATIENTS ENROLLED IN PHASE 3 STUDIES | Treatment | Year 1 | Year 3 |
|---|
| Patient Population(Study number) | Mean (ng/mL) | 10
th – 90
th percentiles
(ng/mL) | Mean (ng/mL) | 10
th – 90
th percentiles
(ng/mL) |
|---|
Low-to-moderate risk
(Studies 1 & 2)
| Sirolimus
(2 mg/day) + CsA
| 7.2 | 3.6 – 11 | – | – |
Sirolimus
(5 mg/day) + CsA
| 14 | 8 – 22 | – | – |
Low-to-moderate risk
(Study 3)
| Sirolimus + CsA | 8.6 | 5 – 13
Months 4 through 12 | 9.1 | 5.4 – 14 |
Sirolimus alone | 19 | 14 – 22
| 16 | 11 – 22 |
High risk
(Study 4)
| Sirolimus + CsA | 15.7 | 5.4 – 27.3
Up to Week 2; observed CsA C
min was 217 (56 – 432) ng/mL
| – | – |
11.8 | 6.2 – 16.9
Week 2 to Week 26; observed CsA C
min range was 174 (71 – 288) ng/mL
| | |
11.5 | 6.3 – 17.3
Week 26 to Week 52; observed CsA C
min was 136 (54.5 – 218) ng/mL
| | |
The withdrawal of cyclosporine and concurrent increases in sirolimus trough concentrations to steady-state required approximately 6 weeks. Following cyclosporine withdrawal, larger sirolimus doses were required due to the absence of the inhibition of sirolimus metabolism and transport by cyclosporine and to achieve higher target sirolimus trough concentrations during concentration-controlled administration [
see
Dosage and Administration (2.1),
Drug Interactions (7.1)].
Pharmacokinetics in Specific Populations
Hepatic Impairment
Sirolimus was administered as a single, oral dose to subjects with normal hepatic function and to patients with Child-Pugh classification A (mild), B (moderate), or C (severe) hepatic impairment. Compared with the values in the normal hepatic function group, the patients with mild, moderate, and severe hepatic impairment had 43%, 94%, and 189% higher mean values for sirolimus AUC, respectively, with no statistically significant differences in mean C
max. As the severity of hepatic impairment increased, there were steady increases in mean sirolimus t
1/2, and decreases in the mean sirolimus clearance normalized for body weight (CL/F/kg).
The maintenance dose of sirolimus should be reduced by approximately one third in patients with mild to moderate hepatic impairment and by approximately one half in patients with severe hepatic impairment [
see
Dosage and Administration (2.5)]. It is not necessary to modify the sirolimus loading dose in patients with mild, moderate, and severe hepatic impairment. Therapeutic drug monitoring is necessary in all patients with hepatic impairment [
see
Dosage and Administration (2.7)].
Renal Impairment
The effect of renal impairment on the pharmacokinetics of sirolimus is not known. However, there is minimal (2.2%) renal excretion of the drug or its metabolites in healthy volunteers. The loading and the maintenance doses of sirolimus need not be adjusted in patients with renal impairment [
see
Dosage and Administration (2.6)].
Pediatric Renal Transplant Patients
Sirolimus pharmacokinetic data were collected in concentration-controlled trials of pediatric renal transplant patients who were also receiving cyclosporine and corticosteroids. The target ranges for trough concentrations were either 10 to 20 ng/mL for the 21 children receiving tablets, or 5 to 15 ng/mL for the one child receiving oral solution. The children aged 6 to 11 years (n = 8) received mean ± SD doses of 1.75 ± 0.71 mg/day (0.064 ± 0.018 mg/kg, 1.65 ± 0.43 mg/m
2). The children aged 12 to 18 years (n = 14) received mean ± SD doses of 2.79 ± 1.25 mg/day (0.053 ± 0.0150 mg/kg, 1.86 ± 0.61 mg/m
2). At the time of sirolimus blood sampling for pharmacokinetic evaluation, the majority (80%) of these pediatric patients received the sirolimus dose at 16 hours after the once-daily cyclosporine dose. See Table 6 below.
TABLE 6: SIROLIMUS PHARMACOKINETIC PARAMETERS (MEAN ± SD) IN PEDIATRIC RENAL TRANSPLANT PATIENTS (MULTIPLE-DOSE CONCENTRATION CONTROL)
Sirolimus co-administered with cyclosporine oral solution [MODIFIED] (e.g., Neoral
® Oral Solution) and/or cyclosporine capsules [MODIFIED] (e.g., Neoral
® Soft Gelatin Capsules).
,As measured by Liquid Chromatographic/Tandem Mass Spectrometric Method (LC/MS/MS)
| Age | n | Body weight | C
max,ss | t
max,ss | C
min,ss | AUC
т,ss | CL/F Oral-dose clearance adjusted by either body weight (kg) or body surface area (m
2).
| CL/F |
|---|
| (y) | | (kg) | (ng/mL) | (h) | (ng/mL) | (ng∙h/mL) | (mL/h/kg) | (L/h/m
2)
|
|---|
6 to 11 | 8 | 27 ± 10 | 22.1 ± 8.9 | 5.88 ± 4.05 | 10.6 ± 4.3 | 356 ± 127 | 214 ± 129 | 5.4 ± 2.8 |
12 to 18 | 14 | 52 ± 15 | 34.5 ± 12.2 | 2.7 ± 1.5 | 14.7 ± 8.6 | 466 ± 236 | 136 ± 57 | 4.7 ± 1.9 |
Table 7 below summarizes pharmacokinetic data obtained in pediatric dialysis patients with chronically impaired renal function.
TABLE 7: SIROLIMUS PHARMACOKINETIC PARAMETERS (MEAN ± SD) IN PEDIATRIC PATIENTS WITH END-STAGE KIDNEY DISEASE MAINTAINED ON HEMODIALYSIS OR PERITONEAL DIALYSIS (1, 3, 9, 15 mg/m
2 SINGLE DOSE)
All subjects received sirolimus oral solution.
| Age Group (y) | n | t
max (h)
| t
1/2 (h)
| CL/F/WT (mL/h/kg) |
|---|
5 to 11 | 9 | 1.1 ± 0.5 | 71 ± 40 | 580 ± 450 |
12 to 18 | 11 | 0.79 ± 0.17 | 55 ± 18 | 450 ± 232 |
Geriatric
Clinical studies of sirolimus did not include a sufficient number of patients >65 years of age to determine whether they will respond differently than younger patients. After the administration of sirolimus oral solution or tablets, sirolimus trough concentration data in renal transplant patients >65 years of age were similar to those in the adult population 18 to 65 years of age.
Gender
Sirolimus clearance in males was 12% lower than that in females; male subjects had a significantly longer t
1/2 than did female subjects (72.3 hours versus 61.3 hours). Dose adjustments based on gender are not recommended.
Race
In the phase 3 trials for the prophylaxis of organ rejection following renal transplantation using sirolimus solution or tablets and cyclosporine oral solution [MODIFIED] (e.g., Neoral
® Oral Solution) and/or cyclosporine capsules [MODIFIED] (e.g., Neoral
® Soft Gelatin Capsules) [
see
Clinical Studies (14)], there were no significant differences in mean trough sirolimus concentrations over time between Black (n = 190) and non-Black (n = 852) patients during the first 6 months after transplantation.
Drug-Drug Interactions
Sirolimus is known to be a substrate for both cytochrome CYP3A4 and P-gp. The pharmacokinetic interaction between sirolimus and concomitantly administered drugs is discussed below. Drug interaction studies have not been conducted with drugs other than those described below.
Cyclosporine: Cyclosporine is a substrate and inhibitor of CYP3A4 and P-gp. Sirolimus should be taken 4 hours after administration of cyclosporine oral solution (MODIFIED) and/or cyclosporine capsules (MODIFIED). Sirolimus concentrations may decrease when cyclosporine is discontinued, unless the sirolimus dose is increased [
see
Dosage and Administration (2.2),
Drug Interactions (7.1)].
In a single-dose drug-drug interaction study, 24 healthy volunteers were administered 10 mg sirolimus tablets either simultaneously or 4 hours after a 300-mg dose of Neoral
® Soft Gelatin Capsules (cyclosporine capsules [MODIFIED]). For simultaneous administration, mean C
max and AUC were increased by 512% and 148%, respectively, relative to administration of sirolimus alone. However, when given 4 hours after cyclosporine administration, sirolimus C
max and AUC were both increased by only 33% compared with administration of sirolimus alone.
In a single dose drug-drug interaction study, 24 healthy volunteers were administered 10 mg sirolimus oral solution either simultaneously or 4 hours after a 300 mg dose of Neoral
® Soft Gelatin Capsules (cyclosporine capsules [MODIFIED]). For simultaneous administration, the mean C
max and AUC of sirolimus, following simultaneous administration were increased by 116% and 230%, respectively, relative to administration of sirolimus alone. However, when given 4 hours after Neoral
® Soft Gelatin Capsules (cyclosporine capsules [MODIFIED]) administration, sirolimus C
max and AUC were increased by only 37% and 80%, respectively, compared with administration of sirolimus alone.
In a single-dose cross-over drug-drug interaction study, 33 healthy volunteers received 5 mg sirolimus oral solution alone, 2 hours before, and 2 hours after a 300 mg dose of Neoral
® Soft Gelatin Capsules (cyclosporine capsules [MODIFIED]). When given 2 hours before Neoral
® Soft Gelatin Capsules (cyclosporine capsules [MODIFIED]) administration, sirolimus C
max and AUC were comparable to those with administration of sirolimus alone. However, when given 2 hours after, the mean C
max and AUC of sirolimus were increased by 126% and 141%, respectively, relative to administration of sirolimus alone.
Mean cyclosporine C
max and AUC were not significantly affected when sirolimus oral solution was given simultaneously or when administered 4 hours after Neoral
® Soft Gelatin Capsules (cyclosporine capsules [MODIFIED]). However, after multiple-dose administration of sirolimus given 4 hours after Neoral
® in renal post-transplant patients over 6 months, cyclosporine oral-dose clearance was reduced, and lower doses of Neoral
® Soft Gelatin Capsules (cyclosporine capsules [MODIFIED]) were needed to maintain target cyclosporine concentration.
In a multiple-dose study in 150 psoriasis patients, sirolimus 0.5, 1.5, and 3 mg/m
2/day was administered simultaneously with Sandimmune
® Oral Solution (cyclosporine Oral Solution) 1.25 mg/kg/day. The increase in average sirolimus trough concentrations ranged between 67% to 86% relative to when sirolimus was administered without cyclosporine. The intersubject variability (% CV) for sirolimus trough concentrations ranged from 39.7% to 68.7%. There was no significant effect of multiple-dose sirolimus on cyclosporine trough concentrations following Sandimmune
® Oral Solution (cyclosporine oral solution) administration. However, the % CV was higher (range 85.9% to 165%) than those from previous studies.
Diltiazem: Diltiazem is a substrate and inhibitor of CYP3A4 and P-gp; sirolimus concentrations should be monitored and a dose adjustment may be necessary [
see
Drug Interactions (7.4)]. The simultaneous oral administration of 10 mg of sirolimus oral solution and 120 mg of diltiazem to 18 healthy volunteers significantly affected the bioavailability of sirolimus. Sirolimus C
max, t
max, and AUC were increased 1.4-, 1.3-, and 1.6-fold, respectively. Sirolimus did not affect the pharmacokinetics of either diltiazem or its metabolites desacetyldiltiazem and desmethyldiltiazem.
Erythromycin: Erythromycin is a substrate and inhibitor of CYP3A4 and P-gp; co-administration of sirolimus oral solution or tablets and erythromycin is not recommended [
see
Warnings and Precautions (5.17),
Drug Interactions (7.2)]. The simultaneous oral administration of 2 mg daily of sirolimus oral solution and 800 mg q 8h of erythromycin as erythromycin ethylsuccinate tablets at steady state to 24 healthy volunteers significantly affected the bioavailability of sirolimus and erythromycin. Sirolimus C
max and AUC were increased 4.4- and 4.2-fold respectively and t
max was increased by 0.4 hr. Erythromycin C
max and AUC were increased 1.6- and 1.7-fold, respectively, and t
max was increased by 0.3 hr.
Ketoconazole: Ketoconazole is a strong inhibitor of CYP3A4 and P-gp; co-administration of sirolimus oral solution or tablets and ketoconazole is not recommended [
see
Warnings and Precautions (5.17),
Drug Interactions (7.2)]. Multiple-dose ketoconazole administration significantly affected the rate and extent of absorption and sirolimus exposure after administration of sirolimus oral solution, as reflected by increases in sirolimus C
max, t
max, and AUC of 4.3-fold, 38%, and 10.9-fold, respectively. However, the terminal t
½ of sirolimus was not changed. Single-dose sirolimus did not affect steady-state 12-hour plasma ketoconazole concentrations.
Rifampin: Rifampin is a strong inducer of CYP3A4 and P-gp; co-administration of sirolimus oral solution or tablets and rifampin is not recommended. In patients where rifampin is indicated, alternative therapeutic agents with less enzyme induction potential should be considered [
see
Warnings and Precautions (5.17),
Drug Interactions (7.2)]. Pretreatment of 14 healthy volunteers with multiple doses of rifampin, 600 mg daily for 14 days, followed by a single 20-mg dose of sirolimus oral solution, greatly decreased sirolimus AUC and C
max by about 82% and 71%, respectively.
Verapamil: Verapamil is a substrate and inhibitor of CYP3A4 and P-gp; sirolimus concentrations should be monitored and a dose adjustment may be necessary; [
see
Drug Interactions (7.4)]. The simultaneous oral administration of 2 mg daily of sirolimus oral solution and 180 mg q 12h of verapamil at steady state to 26 healthy volunteers significantly affected the bioavailability of sirolimus and verapamil. Sirolimus C
max and AUC were increased 2.3- and 2.2-fold, respectively, without substantial change in t
max. The C
max and AUC of the pharmacologically active S(-) enantiomer of verapamil were both increased 1.5-fold and t
max was decreased by 1.2 hr.
Drugs Which May Be Co-administered Without Dose Adjustment
Clinically significant pharmacokinetic drug-drug interactions were not observed in studies of drugs listed below. Sirolimus and these drugs may be co-administered without dose adjustments.
- Acyclovir
- Atorvastatin
- Digoxin
- Glyburide
- Nifedipine
- Norgestrel/ethinyl estradiol (Lo/Ovral
®)
- Prednisolone
- Sulfamethoxazole/trimethoprim (Bactrim
®)
Other Drug-Drug Interactions
Co-administration of sirolimus with other known strong inhibitors of CYP3A4 and/or P-gp (such as voriconazole, itraconazole, telithromycin, or clarithromycin) or other known strong inducers of CYP3A4 and/or P-gp (such as rifabutin) is not recommended [
see
Warnings and Precautions (5.17),
Drug Interactions (7.2)]. In patients in whom strong inhibitors or inducers of CYP3A4 are indicated, alternative therapeutic agents with less potential for inhibition or induction of CYP3A4 should be considered.
Care should be exercised when drugs or other substances that are substrates and/or inhibitors or inducers of CYP3A4 are administered concomitantly with sirolimus. Other drugs that have the potential to increase sirolimus blood concentrations include (but are not limited to):
- Calcium channel blockers: nicardipine.
- Antifungal agents: clotrimazole, fluconazole.
- Antibiotics: troleandomycin.
- Gastrointestinal prokinetic agents: cisapride, metoclopramide.
- Other drugs: bromocriptine, cimetidine, danazol,
protease inhibitors (e.g., for HIV and hepatitis C that include drugs such as ritonavir, indinavir, boceprevir, and telaprevir).
Other drugs that have the potential to decrease sirolimus concentrations include (but are not limited to):
- Anticonvulsants: carbamazepine, phenobarbital, phenytoin.
- Antibiotics: rifapentine.
Other Drug-Food Interactions
Grapefruit juice reduces CYP3A4-mediated drug metabolism. Grapefruit juice must not be taken with sirolimus [
see
Drug Interactions (7.3)].
Drug-Herb Interactions
St. John's Wort (
Hypericum perforatum) induces CYP3A4 and P-gp. Since sirolimus is a substrate for both cytochrome CYP3A4 and P-gp, there is the potential that the use of St. John's Wort in patients receiving sirolimus could result in reduced sirolimus concentrations [
see
Drug Interactions (7.4)].
Sirolimus Oral Solution
The safety and efficacy of sirolimus oral solution for the prevention of organ rejection following renal transplantation were assessed in two randomized, double-blind, multicenter, controlled trials. These studies compared two dose levels of sirolimus oral solution (2 mg and 5 mg, once daily) with azathioprine (Study 1) or placebo (Study 2) when administered in combination with cyclosporine and corticosteroids. Study 1 was conducted in the United States at 38 sites. Seven hundred nineteen (719) patients were enrolled in this trial and randomized following transplantation; 284 were randomized to receive sirolimus oral solution 2 mg/day; 274 were randomized to receive sirolimus oral solution 5 mg/day, and 161 to receive azathioprine 2 to 3 mg/kg/day. Study 2 was conducted in Australia, Canada, Europe, and the United States, at a total of 34 sites. Five hundred seventy-six (576) patients were enrolled in this trial and randomized before transplantation; 227 were randomized to receive sirolimus oral solution 2 mg/day; 219 were randomized to receive sirolimus oral solution 5 mg/day, and 130 to receive placebo. In both studies, the use of anti-lymphocyte antibody induction therapy was prohibited. In both studies, the primary efficacy endpoint was the rate of efficacy failure in the first 6 months after transplantation. Efficacy failure was defined as the first occurrence of an acute rejection episode (confirmed by biopsy), graft loss, or death.
The tables below summarize the results of the primary efficacy analyses from these trials. Sirolimus oral solution, at doses of 2 mg/day and 5 mg/day, significantly reduced the incidence of efficacy failure (statistically significant at the <0.025 level; nominal significance level adjusted for multiple [2] dose comparisons) at 6 months following transplantation compared with both azathioprine and placebo.
TABLE 8: INCIDENCE (%) OF EFFICACY FAILURE AT 6 AND 24 MONTHS FOR STUDY 1
Patients received cyclosporine and corticosteroids.
,Includes patients who prematurely discontinued treatment.
| Parameter | Sirolimus Oral Solution 2 mg/day (n = 284) | Sirolimus Oral Solution 5 mg/day (n = 274) | Azathioprine 2 to 3 mg/kg/day (n = 161) |
|---|
Efficacy failure at 6 months Primary endpoint. | 18.7 | 16.8 | 32.3 |
Components of efficacy failure | | | |
Biopsy-proven acute rejection | 16.5 | 11.3 | 29.2 |
Graft loss | 1.1 | 2.9 | 2.5 |
Death | 0.7 | 1.8 | 0 |
Lost to follow-up | 0.4 | 0.7 | 0.6 |
Efficacy failure at 24 months | 32.8 | 25.9 | 36 |
Components of efficacy failure | | | |
Biopsy-proven acute rejection | 23.6 | 17.5 | 32.3 |
Graft loss | 3.9 | 4.7 | 3.1 |
Death | 4.2 | 3.3 | 0 |
Lost to follow-up | 1.1 | 0.4 | 0.6 |
TABLE 9: INCIDENCE (%) OF EFFICACY FAILURE AT 6 AND 36 MONTHS FOR STUDY 2
Patients received cyclosporine and corticosteroids.
,Includes patients who prematurely discontinued treatment.
| Parameter | Sirolimus Oral Solution 2 mg/day (n = 227) | Sirolimus Oral Solution 5 mg/day (n = 219) | Placebo (n = 130) |
|---|
Efficacy failure at 6 months Primary endpoint. | 30 | 25.6 | 47.7 |
Components of efficacy failure | | | |
Biopsy-proven acute rejection | 24.7 | 19.2 | 41.5 |
Graft loss | 3.1 | 3.7 | 3.9 |
Death | 2.2 | 2.7 | 2.3 |
Lost to follow-up | 0 | 0 | 0 |
Efficacy failure at 36 months | 44.1 | 41.6 | 54.6 |
Components of efficacy failure | | | |
Biopsy-proven acute rejection | 32.2 | 27.4 | 43.9 |
Graft loss | 6.2 | 7.3 | 4.6 |
Death | 5.7 | 5.9 | 5.4 |
Lost to follow-up | 0 | 0.9 | 0.8 |
Patient and graft survival at 1 year were co-primary endpoints. The following table shows graft and patient survival at 1 and 2 years in Study 1, and 1 and 3 years in Study 2. The graft and patient survival rates were similar in patients treated with sirolimus and comparator-treated patients.
TABLE 10: GRAFT AND PATIENT SURVIVAL (%) FOR STUDY 1 (12 AND 24 MONTHS) AND STUDY 2 (12 AND 36 MONTHS)
Patients received cyclosporine and corticosteroids.
,Includes patients who prematurely discontinued treatment.
| Parameter | Sirolimus Oral Solution 2 mg/day | Sirolimus Oral Solution 5 mg/day | Azathioprine 2 to 3 mg/kg/day | Placebo |
|---|
Study 1 | (n = 284) | (n = 274) | (n = 161) | |
Graft survival | | | | |
Month 12 | 94.7 | 92.7 | 93.8 | |
Month 24 | 85.2 | 89.1 | 90.1 | |
Patient survival | | | | |
Month 12 | 97.2 | 96 | 98.1 | |
Month 24 | 92.6 | 94.9 | 96.3 | |
Study 2 | (n = 227) | (n = 219) | | (n = 130) |
Graft survival | | | | |
Month 12 | 89.9 | 90.9 | | 87.7 |
Month 36 | 81.1 | 79.9 | | 80.8 |
Patient survival | | | | |
Month 12 | 96.5 | 95 | | 94.6 |
Month 36 | 90.3 | 89.5 | | 90.8 |
The reduction in the incidence of first biopsy-confirmed acute rejection episodes in patients treated with sirolimus compared with the control groups included a reduction in all grades of rejection.
In Study 1, which was prospectively stratified by race within center, efficacy failure was similar for sirolimus oral solution 2 mg/day and lower for sirolimus oral solution 5 mg/day compared with azathioprine in Black patients. In Study 2, which was not prospectively stratified by race, efficacy failure was similar for both sirolimus oral solution doses compared with placebo in Black patients. The decision to use the higher dose of sirolimus oral solution in Black patients must be weighed against the increased risk of dose-dependent adverse events that were observed with the sirolimus oral solution 5-mg dose [
see
Adverse Reactions (6.1)].
TABLE 11: PERCENTAGE OF EFFICACY FAILURE BY RACE AT 6 MONTHS
Patients received cyclosporine and corticosteroids.
,Includes patients who prematurely discontinued treatment.
| Parameter | Sirolimus Oral Solution 2 mg/day | Sirolimus Oral Solution 5 mg/day | Azathioprine 2–3 mg/kg/day | Placebo |
|---|
Study 1 | | | | |
Black (n = 166) | 34.9 (n = 63) | 18 (n = 61) | 33.3 (n = 42) | |
Non-Black
(n = 553)
| 14 (n = 221) | 16.4 (n = 213) | 31.9 (n = 119) | |
Study 2 | | | | |
Black (n = 66) | 30.8 (n = 26) | 33.7 (n = 27) | | 38.5 (n = 13) |
Non-Black
(n = 510)
| 29.9 (n = 201) | 24.5 (n = 192) | | 48.7 (n = 117) |
Mean glomerular filtration rates (GFR) post-transplant were calculated by using the Nankivell equation at 12 and 24 months for Study 1, and 12 and 36 months for Study 2. Mean GFR was lower in patients treated with cyclosporine and sirolimus oral solution compared with those treated with cyclosporine and the respective azathioprine or placebo control.
TABLE 12: OVERALL CALCULATED GLOMERULAR FILTRATION RATES (Mean ± SEM, cc/min) BY NANKIVELL EQUATION POST-TRANSPLANT
Includes patients who prematurely discontinued treatment.
,Patients who had a graft loss were included in the analysis with GFR set to 0.0.
| Parameter | Sirolimus Oral Solution 2 mg/day | Sirolimus Oral Solution 5 mg/day | Azathioprine 2 to 3 mg/kg/day | Placebo |
|---|
Study 1 | | | | |
Month 12 | 57.4 ± 1.3
(n = 269)
| 54.6 ± 1.3
(n = 248)
| 64.1 ± 1.6)
(n = 149)
| |
Month 24 | 58.4 ± 1.5
(n = 221)
| 52.6 ± 1.5
(n = 222)
| 62.4 ± 1.9
(n = 132)
| |
Study 2 | | | | |
Month 12 | 52.4 ± 1.5
(n = 211)
| 51.5 ± 1.5
(n = 199)
| | 58.0 ± 2.1
(n = 117)
|
Month 36 | 48.1 ± 1.8
(n = 183)
| 46.1 ± 2.0
(n = 177)
| | 53.4 ± 2.7
(n = 102)
|
Within each treatment group in Studies 1 and 2, mean GFR at one-year post-transplant was lower in patients who experienced at least one episode of biopsy-proven acute rejection, compared with those who did not.
Renal function should be monitored, and appropriate adjustment of the immunosuppressive regimen should be considered in patients with elevated or increasing serum creatinine levels [
see
Warnings and Precautions (5.8)].
Sirolimus Tablets
The safety and efficacy of sirolimus oral solution and sirolimus tablets for the prevention of organ rejection following renal transplantation were demonstrated to be clinically equivalent in a randomized, multicenter, controlled trial [
see
Clinical Pharmacology (12.3)].