CLINICAL PHARMACOLOGY
Mechanism Of Action
Mycophenolate mofetil has been demonstrated in
experimental animal models to prolong the survival of allogeneic transplants
(kidney, heart, liver, intestine, limb, small bowel, pancreatic islets, and
bone marrow).
Mycophenolate mofetil has also been shown to reverse
ongoing acute rejection in the canine renal and rat cardiac allograft models.
Mycophenolate mofetil also inhibited proliferative arteriopathy in experimental
models of aortic and cardiac allografts in rats, as well as in primate cardiac
xenografts. Mycophenolate mofetil was used alone or in combination with other
immunosuppressive agents in these studies. Mycophenolate mofetil has been
demonstrated to inhibit immunologically mediated inflammatory responses in
animal models and to inhibit tumor development and prolong survival in murine
tumor transplant models.
Mycophenolate mofetil is rapidly absorbed following oral
administration and hydrolyzed to form MPA, which is the active metabolite. MPA
is a potent, selective, uncompetitive, and reversible inhibitor of inosine
monophosphate dehydrogenase (IMPDH), and therefore inhibits the de novo pathway
of guanosine nucleotide synthesis without incorporation into DNA. Because T-and
B-lymphocytes are critically dependent for their proliferation on de novo
synthesis of purines, whereas other cell types can utilize salvage pathways,
MPA has potent cytostatic effects on lymphocytes. MPA inhibits proliferative
responses of T-and B-lymphocytes to both mitogenic and allospecific
stimulation. Addition of guanosine or deoxyguanosine reverses the cytostatic
effects of MPA on lymphocytes. MPA also suppresses antibody formation by
B-lymphocytes. MPA prevents the glycosylation of lymphocyte and monocyte
glycoproteins that are involved in intercellular adhesion to endothelial cells
and may inhibit recruitment of leukocytes into sites of inflammation and graft
rejection. Mycophenolate mofetil did not inhibit early events in the activation
of human peripheral blood mononuclear cells, such as the production of
interleukin-1 (IL-1) and interleukin-2 (IL-2), but did block the coupling of
these events to DNA synthesis and proliferation.
Pharmacokinetics
Following oral and intravenous administration,
mycophenolate mofetil undergoes rapid and complete metabolism to MPA, the
active metabolite. Oral absorption of the drug is rapid and essentially
complete. MPA is metabolized to form the phenolic glucuronide of MPA (MPAG)
which is not pharmacologically active. The parent drug, mycophenolate mofetil,
can be measured systemically during the intravenous infusion; however, shortly
(about 5 minutes) after the infusion is stopped or after oral administration,
MMF concentration is below the limit of quantitation (0.4 μg/mL).
Absorption
In 12 healthy volunteers, the mean absolute
bioavailability of oral mycophenolate mofetil relative to intravenous
mycophenolate mofetil (based on MPA AUC) was 94%. The area under the
plasma-concentration time curve (AUC) for MPA appears to increase in a
dose-proportional fashion in renal transplant patients receiving multiple doses
of mycophenolate mofetil up to a daily dose of 3 g (see Table 1).
Food (27 g fat, 650 calories) had no effect on the extent
of absorption (MPA AUC) of mycophenolate mofetil when administered at doses of
1.5 g bid to renal transplant patients. However, MPA Cmax was decreased by 40%
in the presence of food (see DOSAGE AND ADMINISTRATION).
Distribution
The mean (±SD) apparent volume of distribution of MPA in
12 healthy volunteers is approximately 3.6 (±1.5) and 4.0 (±1.2) L/kg following
intravenous and oral administration, respectively. MPA, at clinically relevant
concentrations, is 97% bound to plasma albumin. MPAG is 82% bound to plasma
albumin at MPAG concentration ranges that are normally seen in stable renal
transplant patients; however, at higher MPAG concentrations (observed in
patients with renal impairment or delayed renal graft function), the binding of
MPA may be reduced as a result of competition between MPAG and MPA for protein
binding. Mean blood to plasma ratio of radioactivity concentrations was
approximately 0.6 indicating that MPA and MPAG do not extensively distribute
into the cellular fractions of blood.
In vitro studies to evaluate the effect of other agents
on the binding of MPA to human serum albumin (HSA) or plasma proteins showed
that salicylate (at 25 mg/dL with HSA) and MPAG (at ≥ 460 μg/mL with
plasma proteins) increased the free fraction of MPA. At concentrations that
exceeded what is encountered clinically, cyclosporine, digoxin, naproxen,
prednisone, propranolol, tacrolimus, theophylline, tolbutamide, and warfarin
did not increase the free fraction of MPA. MPA at concentrations as high as 100
μg/mL had little effect on the binding of warfarin, digoxin or
propranolol, but decreased the binding of theophylline from 53% to 45% and
phenytoin from 90% to 87%.
Metabolism
Following oral and intravenous dosing, mycophenolate
mofetil undergoes complete metabolism to MPA, the active metabolite. Metabolism
to MPA occurs presystemically after oral dosing. MPA is metabolized principally
by glucuronyl transferase to form the phenolic glucuronide of MPA (MPAG) which
is not pharmacologically active. In vivo, MPAG is converted to MPA via
enterohepatic recirculation. The following metabolites of the
2-hydroxyethyl-morpholino moiety are also recovered in the urine following oral
administration of mycophenolate mofetil to healthy subjects:
N-(2-carboxymethyl)morpholine, N-(2-hydroxyethyl)-morpholine, and the N-oxide
of N-(2-hydroxyethyl)morpholine.
Secondary peaks in the plasma MPA concentration-time
profile are usually observed 6 to 12 hours postdose. The coadministration of
cholestyramine (4 g tid) resulted in approximately a 40% decrease in the MPA
AUC (largely as a consequence of lower concentrations in the terminal portion
of the profile). These observations suggest that enterohepatic recirculation
contributes to MPA plasma concentrations.
Increased plasma concentrations of mycophenolate mofetil
metabolites (MPA 50% increase and MPAG about a 3-fold to 6-fold increase) are
observed in patients with renal insufficiency (see CLINICAL PHARMACOLOGY:
Special Populations).
Excretion
Negligible amount of drug is excreted as MPA ( < 1% of
dose) in the urine. Orally administered radiolabeled mycophenolate mofetil
resulted in complete recovery of the administered dose, with 93% of the
administered dose recovered in the urine and 6% recovered in feces. Most (about
87%) of the administered dose is excreted in the urine as MPAG. At clinically
encountered concentrations, MPA and MPAG are usually not removed by
hemodialysis. However, at high MPAG plasma concentrations ( > 100 μg/mL),
small amounts of MPAG are removed. Bile acid sequestrants, such as
cholestyramine, reduce MPA AUC by interfering with enterohepatic circulation of
the drug (see OVERDOSAGE).
Mean (±SD) apparent half-life and plasma clearance of MPA
are 17.9 (±6.5) hours and 193 (±48) mL/min following oral administration and
16.6 (±5.8) hours and 177 (±31) mL/min following intravenous administration,
respectively.
Pharmacokinetics in Healthy Volunteers, Renal, Cardiac,
and Hepatic Transplant Patients
Shown below are the mean (±SD) pharmacokinetic parameters
for MPA following the administration of mycophenolate mofetil given as single
doses to healthy volunteers and multiple doses to renal, cardiac, and hepatic
transplant patients. In the early posttransplant period ( < 40 days
posttransplant), renal, cardiac, and hepatic transplant patients had mean MPA
AUCs approximately 20% to 41% lower and mean Cmax approximately 32% to 44%
lower compared to the late transplant period (3 to 6 months posttransplant).
Mean MPA AUC values following administration of 1 g bid
intravenous mycophenolate mofetil over 2 hours to renal transplant patients for
5 days were about 24% higher than those observed after oral administration of a
similar dose in the immediate posttransplant phase. In hepatic transplant
patients, administration of 1 g bid intravenous CellCept followed by 1.5 g bid
oral CellCept resulted in mean MPA AUC values similar to those found in renal
transplant patients administered 1 g CellCept bid.
Table 1 : Pharmacokinetic Parameters for MPA [mean (±SD)]
Following Administration of Mycophenolate Mofetil to Healthy Volunteers (Single
Dose), Renal, Cardiac, and Hepatic Transplant Patients (Multiple Doses)
|
Dose/Route |
Tmax (h) |
C'max (μg/mL) |
Total AUC (μg•h/mL) |
Healthy Volunteers (single dose) |
1 g/oral |
0.80
(±0.36)
(n=129) |
24.5
(±9.5)
(n=129) |
63.9
(±16.2)
(n=117) |
Renal Transplant Patients (bid dosing) Time After Transplantation |
Dose/Route |
Tmax (h) |
Cmax (μg/mL) |
Interdosing Interval AUC (0-12h) (μg•h/mL) |
5 days |
1 g/iv |
1.58
(±0.46)
(n=31) |
12.0
(±3.82)
(n=31) |
40.8
(±11.4)
(n=31) |
6 days |
1 g/oral |
1.33
(±1.05)
(n=31) |
10.7
(±4.83)
(n=31) |
32.9
(±15.0)
(n=31) |
Early ( < 40 days) |
1 g/oral |
1.31
(±0.76)
(n=25) |
8.16
(±4.50)
(n=25) |
27.3
(±10.9)
(n=25) |
Early ( < 40 days) |
1.5 g/oral |
1.21
(±0.81)
(n=27) |
13.5
(±8.18)
(n=27) |
38.4
(±15.4)
(n=27) |
Late ( > 3 months) |
1.5 g/oral |
0.90
(±0.24)
(n=23) |
24.1
(±12.1)
(n=23) |
65.3
(±35.4)
(n=23) |
Cardiac Transplant Patients (bid dosing) Time After Transplantation |
Dose/Route |
Tmax (h) |
Cmax (μg/mL) |
Interdosing Interval AUC (0-12h) (μg•h/mL) |
Early (Day before discharge) |
1.5 g/oral |
1.8
(±1.3)
(n=11) |
11.5
(±6.8)
(n=11) |
43.3
(±20.8)
(n=9) |
Late ( > 6 months) |
1.5 g/oral |
1.1
(±0.7)
(n=52) |
20.0
(±9.4)
(n=52) |
54.1a
(±20.4)
(n=49) |
Hepatic Transplant Patients (bid dosing) Time After Transplantation |
Dose/Route |
Tmax (h) |
Cmax (μg/mL) |
Interdosing Interval AUC (0-12h) (μg•h/mL) |
4 to 9 days |
1 g/iv |
1.50
(±0.517)
(n=22) |
17.0
(±12.7)
(n=22) |
34.0
(±17.4)
(n=22) |
Early (5 to 8 days) |
1.5 g/oral |
1.15
(±0.432)
(n=20) |
13.1
(±6.76)
(n=20) |
29.2
(±11.9)
(n=20) |
Late ( > 6 months) |
1.5 g/oral |
1.54
(±0.51)
(n=6) |
19.3
(±11.7)
(n=6) |
49.3
(±14.8)
(n=6) |
aAUC(0-12h) values quoted are extrapolated from data from
samples collected over 4 hours. |
Two 500 mg tablets have been shown to be bioequivalent to
four 250 mg capsules. Five mL of the 200 mg/mL constituted oral suspension have
been shown to be bioequivalent to four 250 mg capsules.
Special Populations
Shown below are the mean (±SD) pharmacokinetic parameters
for MPA following the administration of oral mycophenolate mofetil given as
single doses to non-transplant subjects with renal or hepatic impairment.
Table 2 : Pharmacokinetic Parameters for MPA [mean (±SD)]
Following Single Doses of Mycophenolate Mofetil Capsules in Chronic Renal and
Hepatic Impairment
Renal Impairment (no. of patients) |
Dose |
Tmax (h) |
Cmax (μg/mL) |
AUC(0-96h) (μg•h/mL) |
Healthy Volunteers GFR > 80 mL/min/1.73 m² (n=6) |
1 g |
0.75 (±0.27) |
25.3 (±7.99) |
45.0 (±22.6) |
Mild Renal Impairment GFR 50 to 80 mL/min/1.73 m² (n=6) |
1 g |
0.75 (±0.27) |
26.0 (±3.82) |
59.9 (±12.9) |
Moderate Renal Impairment GFR 25 to 49 mL/min/1.73 m² (n=6) |
1 g |
0.75 (±0.27) |
19.0 (±13.2) |
52.9 (±25.5) |
Severe Renal Impairment GFR < 25 mL/min/1.73 m² (n=7) |
1 g |
1.00 (±0.41) |
16.3 (±10.8) |
78.6 (±46.4) |
Hepatic Impairment (no. of patients) |
Dose |
Tmax (h) |
Cmax (μg/mL) |
AUC(0-48h) (μg•h/mL) |
Healthy Volunteers (n=6) |
1 g |
0.63 (±0.14) |
24.3 (±5.73) |
29.0 (±5.78) |
Alcoholic Cirrhosis (n=18) |
1 g |
0.85 (±0.58) |
22.4 (±10.1) |
29.8 (±10.7) |
Renal Insufficiency
In a single-dose study, MMF was
administered as capsule or intravenous infusion over 40 minutes. Plasma MPA AUC
observed after oral dosing to volunteers with severe chronic renal impairment
[glomerular filtration rate (GFR) < 25 mL/min/1.73 m²] was about
75% higher relative to that observed in healthy volunteers (GFR > 80
mL/min/1.73 m²). In addition, the single-dose plasma MPAG AUC was
3-fold to 6-fold higher in volunteers with severe renal impairment than in
volunteers with mild renal impairment or healthy volunteers, consistent with
the known renal elimination of MPAG. No data are available on the safety of
long-term exposure to this level of MPAG.
Plasma MPA AUC observed after
single-dose (1 g) intravenous dosing to volunteers (n=4) with severe chronic
renal impairment (GFR < 25 mL/min/1.73 m²) was 62.4 μg•h/mL
(±19.3). Multiple dosing of mycophenolate mofetil in patients with severe
chronic renal impairment has not been studied (see PRECAUTIONS: Patients
with Renal Impairment and DOSAGE AND ADMINISTRATION).
In patients with delayed renal graft function
posttransplant, mean MPA AUC(0-12h) was comparable to that seen in
posttransplant patients without delayed renal graft function. There is a
potential for a transient increase in the free fraction and concentration of
plasma MPA in patients with delayed renal graft function. However, dose
adjustment does not appear to be necessary in patients with delayed renal graft
function. Mean plasma MPAG AUC(0-12h) was 2-fold to 3-fold higher than in
posttransplant patients without delayed renal graft function (see PRECAUTIONS:
Patients with Renal Impairment and DOSAGE AND ADMINISTRATION).
In 8 patients with primary graft non-function following
renal transplantation, plasma concentrations of MPAG accumulated about 6-fold
to 8-fold after multiple dosing for 28 days. Accumulation of MPA was about
1-fold to 2-fold.
The pharmacokinetics of mycophenolate mofetil are not
altered by hemodialysis. Hemodialysis usually does not remove MPA or MPAG. At
high concentrations of MPAG ( > 100 μg/mL), hemodialysis removes only
small amounts of MPAG.
Hepatic Insufficiency
In a single-dose (1 g oral) study of 18 volunteers with
alcoholic cirrhosis and 6 healthy volunteers, hepatic MPA glucuronidation
processes appeared to be relatively unaffected by hepatic parenchymal disease
when pharmacokinetic parameters of healthy volunteers and alcoholic cirrhosis
patients within this study were compared. However, it should be noted that for
unexplained reasons, the healthy volunteers in this study had about a 50% lower
AUC as compared to healthy volunteers in other studies, thus making comparisons
between volunteers with alcoholic cirrhosis and healthy volunteers difficult.
Effects of hepatic disease on this process probably depend on the particular
disease. Hepatic disease with other etiologies, such as primary biliary
cirrhosis, may show a different effect. In a single-dose (1 g intravenous)
study of 6 volunteers with severe hepatic impairment (aminopyrine breath test
less than 0.2% of dose) due to alcoholic cirrhosis, MMF was rapidly converted
to MPA. MPA AUC was 44.1 μg•h/mL (±15.5).
Pediatrics
The pharmacokinetic parameters of MPA and MPAG have been
evaluated in 55 pediatric patients (ranging from 1 year to 18 years of age)
receiving CellCept oral suspension at a dose of 600 mg/m² bid (up to
a maximum of 1 g bid) after allogeneic renal transplantation. The
pharmacokinetic data for MPA is provided in Table 3.
Table 3 : Mean (±SD) Computed Pharmacokinetic
Parameters for MPA by Age and Time After Allogeneic Renal Transplantation
Age Group |
(n) |
Time |
|
T max (h) |
Dose Adjusteda C max (μg/mL) |
Dose Adjusteda AUC0-12 (μg•h/mL) |
1 to < 2 yr |
(6)d |
Early (Day 7) |
3.03 |
(4.70) |
10.3 |
(5.80) |
22.5 |
(6.66) |
1 to < 6 yr |
(17) |
1.63 |
(2.85) |
13.2 |
(7.16) |
27.4 |
(9.54) |
6 to < 12 yr |
(16) |
0.940 |
(0.546) |
13.1 |
(6.30) |
33.2 |
(12.1) |
12 to 18 yr |
(21) |
1.16 |
(0.830) |
11.7 |
(10.7) |
26.3 |
(9.14)b |
1 to < 2 yr |
(4)d |
Late (Month 3) |
0.725 |
(0.276) |
23.8 |
(13.4) |
47.4 |
(14.7) |
1 to < 6 yr |
(15) |
0.989 |
(0.511) |
22.7 |
(10.1) |
49.7 |
(18.2) |
6 to < 12 yr |
(14) |
1.21 |
(0.532) |
27.8 |
(14.3) |
61.9 |
(19.6) |
12 to 18 yr |
(17) |
0.978 |
(0.484) |
17.9 |
(9.57) |
53.6 |
(20.3)c |
1 to < 2 yr |
(4)d |
Late (Month 9) |
0.604 |
(0.208) |
25.6 |
(4.25) |
55.8 |
(11.6) |
1 to < 6 yr |
(12) |
0.869 |
(0.479) |
30.4 |
(9.16) |
61.0 |
(10.7) |
6 to < 12 yr |
(11) |
1.12 |
(0.462) |
29.2 |
(12.6) |
66.8 |
(21.2) |
12 to 18 yr |
(14) |
1.09 |
(0.518) |
18.1 |
(7.29) |
56.7 |
(14.0) |
aadjusted to a dose of 600 mg/m²
bn=20 cn=16 da subset of 1 to < 6 yr |
The CellCept oral suspension
dose of 600 mg/m² bid (up to a maximum of 1 g bid) achieved mean MPA
AUC values in pediatric patients similar to those seen in adult renal
transplant patients receiving CellCept capsules at a dose of 1 g bid in the
early posttransplant period. There was wide variability in the data. As
observed in adults, early posttransplant MPA AUC values were approximately 45%
to 53% lower than those observed in the later posttransplant period ( > 3
months). MPA AUC values were similar in the early and late posttransplant
period across the 1 year to 18 year age range.
Gender
Data obtained from several
studies were pooled to look at any gender-related differences in the
pharmacokinetics of MPA (data were adjusted to 1 g oral dose). Mean (±SD) MPA
AUC(0-12h) for males (n=79) was 32.0 (±14.5) and for females (n=41) was 36.5
(±18.8) μg•h/mL while mean (±SD) MPA Cmax was 9.96 (±6.19) in the males
and 10.6 (±5.64) μg/mL in the females. These differences are not of
clinical significance.
Geriatrics
Pharmacokinetics in the elderly
have not been studied.
Clinical Studies
Adults
The safety and efficacy of CellCept in combination with
corticosteroids and cyclosporine for the prevention of organ rejection were
assessed in randomized, double-blind, multicenter trials in renal (3 trials),
in cardiac (1 trial), and in hepatic (1 trial) adult transplant patients.
Renal Transplant
Adults
The three renal studies compared two dose levels of oral
CellCept (1 g bid and 1.5 g bid) with azathioprine (2 studies) or placebo (1
study) when administered in combination with cyclosporine (Sandimmune®)
and corticosteroids to prevent acute rejection episodes. One study also
included antithymocyte globulin (ATGAM®) induction therapy.
These studies are described by geographic location of the investigational
sites. One study was conducted in the USA at 14 sites, one study was conducted
in Europe at 20 sites, and one study was conducted in Europe, Canada, and
Australia at a total of 21 sites.
The primary efficacy endpoint was the proportion of
patients in each treatment group who experienced treatment failure within the
first 6 months after transplantation (defined as biopsy-proven acute rejection
on treatment or the occurrence of death, graft loss or eary termination from
the study for any reason without prior biopsy-proven rejection). CellCept, when
administered with antithymocyte globulin (ATGAM®) induction
(one study) and with cyclosporine and corticosteroids (all three studies), was
compared to the following three therapeutic regimens: (1) antithymocyte
globulin (ATGAM®) induction/azathioprine/cyclosporine/corticosteroids,
(2) azathioprine/cyclosporine/corticosteroids, and (3)
cyclosporine/corticosteroids.
CellCept, in combination with corticosteroids and
cyclosporine reduced (statistically significant at 0.05 level) the incidence of
treatment failure within the first 6 months following transplantation. Table 4 and
Table 5 summarize the results of these studies. These tables show (1) the
proportion of patients experiencing treatment failure, (2) the proportion of
patients who experienced biopsy-proven acute rejection on treatment, and (3)
early termination, for any reason other than graft loss or death, without a
prior biopsy-proven acute rejection episode. Patients who prematurely
discontinued treatment were followed for the occurrence of death or graft loss,
and the cumulative incidence of graft loss and patient death are summarized
separately. Patients who prematurely discontinued treatment were not followed
for the occurrence of acute rejection after termination. More patients
receiving CellCept discontinued without prior biopsy-proven rejection, death or
graft loss than discontinued in the control groups, with the highest rate in
the CellCept 3 g/day group. Therefore, the acute rejection rates may be
underestimates, particularly in the CellCept 3 g/day group.
Table 4 : Renal Transplant Studies Incidence of
Treatment Failure (Biopsy-proven Rejection or Early Termination for Any Reason)
USA Studya (N=499 patients) |
CellCept 2 g/day
(n=167 patients) |
CellCept 3 g/day
(n=166 patients) |
Azathioprine 1 to 2 mg/kg/day
(n=166 patients) |
All treatment failures |
31.1% |
31.3% |
47.6% |
Early termination without prior acute rejectionb |
9.6% |
12.7% |
6.0% |
Biopsy-proven rejection episode on treatment |
19.8% |
17.5% |
38.0% |
Europe/Canada/ Australia Studyc (N=503 patients) |
CellCept 2 g/day (n=173 patients) |
CellCept 3 g/day (n=164 patients) |
Azathioprine 100 to 150 mg/day (n=166 patients) |
All treatment failures |
38.2% |
34.8% |
50.0% |
Early termination without prior acute rejectionb |
13.9% |
15.2% |
10.2% |
Biopsy-proven rejection episode on treatment |
19.7% |
15.9% |
35.5% |
Europe Studyd (N=491 patients) |
CellCept 2 g/day (n=165 patients) |
CellCept 3 g/day (n=160 patients) |
Placebo (n=166 patients) |
All treatment failures |
30.3% |
38.8% |
56.0% |
Early termination without prior acute rejectionb |
11.5% |
22.5% |
7.2% |
Biopsy-proven rejection episode on treatment |
17.0% |
13.8% |
46.4% |
aAntithymocyte globulin induction/MMF or
azathioprine/cyclosporine/corticosteroids.
bDoes not include death and graft loss as reason for early
termination.
cMMF or azathioprine/cyclosporine/corticosteroids.
dMMF or placebo/cyclosporine/corticosteroids. |
The cumulative incidence of
12-month graft loss or patient death is presented below. No advantage of
CellCept with respect to graft loss or patient death was established.
Numerically, patients receiving CellCept 2 g/day and 3 g/day experienced a
better outcome than controls in all three studies; patients receiving CellCept
2 g/day experienced a better outcome than CellCept 3 g/day in two of the three
studies. Patients in all treatment groups who terminated treatment early
were found to have a poor outcome with respect to graft loss or patient death
at 1 year.
Table 5 : Renal Transplant Studies Cumulative
Incidence of Combined Graft Loss or Patient Death at 12 Months
Study |
CellCept 2 g/day |
CellCept 3 g/day |
Control (Azathioprine or Placebo) |
USA |
8.5% |
11.5% |
12.2% |
Europe/Canada/Australia |
11.7% |
11.0% |
13.6% |
Europe |
8.5% |
10.0% |
11.5% |
Pediatrics
One open-label, safety and
pharmacokinetic study of CellCept oral suspension 600 mg/m² bid (up
to 1 g bid) in combination with cyclosporine and corticosteroids was performed
at centers in the US (9), Europe (5) and Australia (1) in 100 pediatric
patients (3 months to 18 years of age) for the prevention of renal allograft
rejection. CellCept was well tolerated in pediatric patients (see ADVERSE REACTIONS),
and the pharmacokinetics profile was similar to that seen in adult patients
dosed with 1 g bid CellCept capsules (see CLINICAL PHARMACOLOGY: Pharmacokinetics).
The rate of biopsy-proven rejection was similar across the age groups (3 months
to < 6 years, 6 years to < 12 years, 12 years to 18 years). The overall
biopsy-proven rejection rate at 6 months was comparable to adults. The combined
incidence of graft loss (5%) and patient death (2%) at 12 months posttransplant
was similar to that observed in adult renal transplant patients.
Cardiac Transplant
A double-blind, randomized, comparative, parallel-group,
multicenter study in primary cardiac transplant recipients was performed at 20
centers in the United States, 1 in Canada, 5 in Europe and 2 in Australia. The
total number of patients enrolled was 650; 72 never received study drug and 578
received study drug. Patients received CellCept 1.5 g bid (n=289) or
azathioprine 1.5 to 3 mg/kg/day (n=289), in combination with cyclosporine
(Sandimmune® or Neoral®) and
corticosteroids as maintenance immunosuppressive therapy. The two primary
efficacy endpoints were: (1) the proportion of patients who, after
transplantation, had at least one endomyocardial biopsy-proven rejection with
hemodynamic compromise, or were retransplanted or died, within the first 6
months, and (2) the proportion of patients who died or were retransplanted
during the first 12 months following transplantation. Patients who prematurely
discontinued treatment were followed for the occurrence of allograft rejection
for up to 6 months and for the occurrence of death for 1 year.
Rejection: No difference was established
between CellCept and azathioprine (AZA) with respect to biopsy-proven rejection
with hemodynamic compromise.
Survival: CellCept was shown to be at least as
effective as AZA in preventing death or retransplantation at 1 year (see Table
6).
Table 6 : Rejection at 6 Months/Death or
Retransplantation at 1 Year
|
All Patients |
Treated Patients |
AZA
N = 323 |
CellCept
N = 327 |
AZA
N = 289 |
CellCept
N = 289 |
Biopsy-proven rejection with hemodynamic compromise at 6 monthsa |
121
(38%) |
120
(37%) |
100
(35%) |
92
(32%) |
Death or retransplantation at 1 year |
49
(15.2%) |
42
(12.8%) |
33
(11.4%) |
18
(6.2%) |
aHemodynamic compromise occurred if any of the following
criteria were met: pulmonary capillary wedge pressure ≥ 20 mm or a 25%
increase; cardiac index < 2.0 L/min/m² or a 25% decrease; ejection
fraction ≤ 30%; pulmonary artery oxygen saturation ≤ 60% or a 25%
decrease; presence of new S3 gallop; fractional shortening was ≤ 20% or a
25% decrease; inotropic support required to manage the clinical condition. |
Hepatic Transplant
A double-blind, randomized, comparative, parallel-group,
multicenter study in primary hepatic transplant recipients was performed at 16
centers in the United States, 2 in Canada, 4 in Europe and 1 in Australia. The
total number of patients enrolled was 565. Per protocol, patients received
CellCept 1 g bid intravenously for up to 14 days followed by CellCept 1.5 g bid
orally or azathioprine 1 to 2 mg/kg/day intravenously followed by azathioprine
1 to 2 mg/kg/day orally, in combination with cyclosporine (Neoral®)
and corticosteroids as maintenance immunosuppressive therapy. The actual median
oral dose of azathioprine on study was 1.5 mg/kg/day (range of 0.3 to 3.8
mg/kg/day) initially and 1.26 mg/kg/day (range of 0.3 to 3.8 mg/kg/day) at 12
months. The two primary endpoints were: (1) the proportion of patients who
experienced, in the first 6 months posttransplantation, one or more episodes of
biopsy-proven and treated rejection or death or retransplantation, and (2) the
proportion of patients who experienced graft loss (death or retransplantation)
during the first 12 months posttransplantation. Patients who prematurely
discontinued treatment were followed for the occurrence of allograft rejection
and for the occurrence of graft loss (death or retransplantation) for 1 year.
Results
In combination with corticosteroids and cyclosporine,
CellCept obtained a lower rate of acute rejection at 6 months and a similar
rate of death or retransplantation at 1 year compared to azathioprine.
Table 7 : Rejection at 6 Months/Death or
Retransplantation at 1 Year
|
AZA
N = 287 |
CellCept
N = 278 |
Biopsy-proven, treated rejection at 6 months (includes death or retransplantation) |
137 (47.7%) |
107 (38.5%) |
Death or retransplantation at 1 year |
42 (14.6%) |
41 (14.7%) |