CLINICAL PHARMACOLOGY
Mechanism Of Action
Raloxifene is an estrogen agonist/antagonist, commonly
referred to as a selective estrogen receptor modulator (SERM). The biological
actions of raloxifene are largely mediated through binding to estrogen receptors.
This binding results in activation of estrogenic pathways in some tissues
(agonism) and blockade of estrogenic pathways in others (antagonism). The
agonistic or antagonistic action of raloxifene depends on the extent of
recruitment of coactivators and corepressors to estrogen receptor (ER) target
gene promoters.
Raloxifene appears to act as an estrogen agonist in bone.
It decreases bone resorption and bone turnover, increases bone mineral density
(BMD) and decreases fracture incidence. Preclinical data demonstrate that
raloxifene is an estrogen antagonist in uterine and breast tissues. These
results are consistent with findings in clinical trials, which suggest that
EVISTA lacks estrogen-like effects on the uterus and breast tissue.
Pharmacodynamics
Decreases in estrogen levels after oophorectomy or
menopause lead to increases in bone resorption and accelerated bone loss. Bone
is initially lost rapidly because the compensatory increase in bone formation
is inadequate to offset resorptive losses. In addition to loss of estrogen,
this imbalance between resorption and formation may be due to age-related
impairment of osteoblasts or their precursors. In some women, these changes
will eventually lead to decreased bone mass, osteoporosis, and increased risk
for fractures, particularly of the spine, hip, and wrist. Vertebral fractures
are the most common type of osteoporotic fracture in postmenopausal women.
In both the osteoporosis treatment and prevention trials,
EVISTA therapy resulted in consistent, statistically significant suppression of
bone resorption and bone formation, as reflected by changes in serum and urine
markers of bone turnover (e.g., bone-specific alkaline phosphatase,
osteocalcin, and collagen breakdown products). The suppression of bone turnover
markers was evident by 3 months and persisted throughout the 36-month and
24-month observation periods.
In a 31-week, open-label, radiocalcium kinetics study, 33
early postmenopausal women were randomized to treatment with once-daily EVISTA
60 mg, cyclic estrogen/progestin (0.625 mg conjugated estrogens daily with 5 mg
medroxyprogesterone acetate daily for the first 2 weeks of each month [hormone
therapy]), or no treatment. Treatment with either EVISTA or hormone therapy was
associated with reduced bone resorption and a positive shift in calcium balance
(-82 mg Ca/day and +60 mg Ca/day, respectively, for EVISTA and -162 mg Ca/day
and +91 mg Ca/day, respectively, for hormone therapy).
There were small decreases in serum total calcium,
inorganic phosphate, total protein, and albumin, which were generally of lesser
magnitude than decreases observed during estrogen or hormone therapy. Platelet
count was also decreased slightly and was not different from estrogen therapy.
Pharmacokinetics
The disposition of raloxifene has been evaluated in more
than 3000 postmenopausal women in selected raloxifene osteoporosis treatment
and prevention clinical trials, using a population approach. Pharmacokinetic
data also were obtained in conventional pharmacology studies in 292
postmenopausal women. Raloxifene exhibits high within-subject variability
(approximately 30% coefficient of variation) of most pharmacokinetic
parameters. Table 3 summarizes the pharmacokinetic parameters of raloxifene.
Absorption
Raloxifene is absorbed rapidly after oral administration.
Approximately 60% of an oral dose is absorbed, but presystemic glucuronide
conjugation is extensive. Absolute bioavailability of raloxifene is 2%. The
time to reach average maximum plasma concentration and bioavailability are functions
of systemic interconversion and enterohepatic cycling of raloxifene and its
glucuronide metabolites.
Administration of raloxifene HCl with a standardized,
high-fat meal increases the absorption of raloxifene (Cmax 28% and AUC 16%),
but does not lead to clinically meaningful changes in systemic exposure. EVISTA
can be administered without regard to meals.
Distribution
Following oral administration of single doses ranging
from 30 to 150 mg of raloxifene HCl, the apparent volume of distribution is
2348 L/kg and is not dose dependent.
Raloxifene and the monoglucuronide conjugates are highly
(95%) bound to plasma proteins. Raloxifene binds to both albumin and
α1-acid glycoprotein, but not to sex-steroid binding globulin.
Metabolism
Biotransformation and disposition of raloxifene in humans
have been determined following oral administration of 14C-labeled
raloxifene. Raloxifene undergoes extensive first-pass metabolism to the
glucuronide conjugates: raloxifene-4'-glucuronide,
raloxifene-6-glucuronide, and raloxifene-6, 4'-diglucuronide. No other
metabolites have been detected, providing strong evidence that raloxifene is
not metabolized by cytochrome P450 pathways. Unconjugated raloxifene comprises less
than 1% of the total radiolabeled material in plasma. The terminal log-linear
portions of the plasma concentration curves for raloxifene and the glucuronides
are generally parallel. This is consistent with interconversion of raloxifene
and the glucuronide metabolites.
Following intravenous administration, raloxifene is
cleared at a rate approximating hepatic blood flow. Apparent oral clearance is
44.1 L/kg•hr. Raloxifene and its glucuronide conjugates are interconverted by
reversible systemic metabolism and enterohepatic cycling, thereby prolonging
its plasma elimination half-life to 27.7 hours after oral dosing.
Results from single oral doses of raloxifene predict
multiple-dose pharmacokinetics. Following chronic dosing, clearance ranges from
40 to 60 L/kg•hr. Increasing doses of raloxifene HCl (ranging from 30 to 150
mg) result in slightly less than a proportional increase in the area under the
plasma time concentration curve (AUC).
Excretion
Raloxifene is primarily excreted in feces, and less than
0.2% is excreted unchanged in urine. Less than 6% of the raloxifene dose is
eliminated in urine as glucuronide conjugates.
Table 3: Summary of Raloxifene Pharmacokinetic
Parameters in the Healthy Postmenopausal Woman
|
Cmaxa,b
(ng/mL)/
(mg/kg) |
t½ (hr)a |
AUC0-∞a,b (ng•hr/mL)/ (mg/kg) |
CL/Fa (L/kg•hr) |
V/Fa (L/kg) |
Single Dose |
Mean |
0.50 |
27.7 |
27.2 |
44.1 |
2348 |
CVa (%) |
52 |
10.7 to 273c |
44 |
46 |
52 |
Multiple Dose |
Mean |
1.36 |
32.5 |
24.2 |
47.4 |
2853 |
CVa (%) |
37 |
15.8 to 86.6c |
36 |
41 |
56 |
aAbbreviations: Cmax = maximum plasma
concentration, t½ = half-life, AUC = area under the curve, CL = clearance, V
= volume of distribution, F = bioavailability, CV = coefficient of variation.
bData normalized for dose in mg and body weight in kg.
cRange of observed half-life. |
Special Populations
Pediatric - The pharmacokinetics of raloxifene has
not been evaluated in a pediatric population [see Use in Specific
Populations].
Geriatric - No differences in raloxifene pharmacokinetics
were detected with regard to age (range 42 to 84 years) [see Use in Specific
Populations].
Gender - Total extent of exposure and oral
clearance, normalized for lean body weight, are not significantly different
between age-matched female and male volunteers.
Race - Pharmacokinetic differences due to race
have been studied in 1712 women, including 97.5% White, 1.0% Asian, 0.7%
Hispanic, and 0.5% Black in the osteoporosis treatment trial and in 1053 women,
including 93.5% White, 4.3% Hispanic, 1.2% Asian, and 0.5% Black in the
osteoporosis prevention trials. There were no discernible differences in
raloxifene plasma concentrations among these groups; however, the influence of
race cannot be conclusively determined.
Renal Impairment - In the osteoporosis treatment
and prevention trials, raloxifene concentrations in women with mild renal
impairment are similar to women with normal creatinine clearance. When a single
dose of 120 mg raloxifene HCl was administered to 10 renally impaired males [7
moderate impairment (CrCl = 31-50 mL/min); 3 severe impairment (CrCl ≤ 30
mL/min)] and to 10 healthy males (CrCl > 80 mL/min), plasma raloxifene
concentrations were 122% (AUC0-∞) higher in renally impaired patients
than those of healthy volunteers. Raloxifene should be used with caution in
patients with moderate or severe renal impairment [see WARNINGS AND
PRECAUTIONS and Use in Specific Populations].
Hepatic Impairment - The disposition of raloxifene
was compared in 9 patients with mild (Child-Pugh Class A) hepatic impairment
(total bilirubin ranging from 0.6 to 2 mg/dL) to 8 subjects with normal hepatic
function following a single dose of 60 mg raloxifene HCl. Apparent clearance of
raloxifene was reduced 56% and the half-life of raloxifene was not altered in
patients with mild hepatic impairment. Plasma raloxifene concentrations were
approximately 150% higher than those in healthy volunteers and correlated with
total bilirubin concentrations. The pharmacokinetics of raloxifene has not been
studied in patients with moderate or severe hepatic impairment. Raloxifene
should be used with caution in patients with hepatic impairment [see
WARNINGS AND PRECAUTIONS and Use in Specific Populations].
Drug Interactions
Cholestyramine - Cholestyramine, an anion exchange
resin, causes a 60% reduction in the absorption and enterohepatic cycling of
raloxifene after a single dose. Although not specifically studied, it is anticipated
that other anion exchange resins would have a similar effect [see DRUG
INTERACTIONS].
Warfarin - In vitro, raloxifene did not interact
with the binding of warfarin. The concomitant administration of EVISTA and
warfarin, a coumarin derivative, has been assessed in a single-dose study. In
this study, raloxifene had no effect on the pharmacokinetics of warfarin.
However, a 10% decrease in prothrombin time was observed in the single-dose
study. In the osteoporosis treatment trial, there were no clinically relevant
effects of warfarin co-administration on plasma concentrations of raloxifene [see
DRUG INTERACTIONS].
Other Highly Protein-Bound Drugs - In the
osteoporosis treatment trial, there were no clinically relevant effects of
co-administration of other highly protein-bound drugs (e.g., gemfibrozil) on
plasma concentrations of raloxifene. In vitro, raloxifene did not interact with
the binding of phenytoin, tamoxifen, or warfarin (see above) [see DRUG INTERACTIONS].
Ampicillin and Amoxicillin - Peak concentrations
of raloxifene and the overall extent of absorption are reduced 28% and 14%,
respectively, with co-administration of ampicillin. These reductions are consistent
with decreased enterohepatic cycling associated with antibiotic reduction of
enteric bacteria. However, the systemic exposure and the elimination rate of
raloxifene were not affected. In the osteoporosis treatment trial,
co-administration of amoxicillin had no discernible differences in plasma raloxifene
concentrations [see DRUG INTERACTIONS].
Antacids - Concomitant administration of calcium
carbonate or aluminum and magnesium hydroxidecontaining antacids does not
affect the systemic exposure of raloxifene [see DRUG INTERACTIONS].
Corticosteroids - The chronic administration of
raloxifene in postmenopausal women has no effect on the pharmacokinetics of
methylprednisolone given as a single oral dose [see DRUG INTERACTIONS].
Digoxin - Raloxifene has no effect on the
pharmacokinetics of digoxin [see DRUG INTERACTIONS].
Cyclosporine - Concomitant administration of
EVISTA with cyclosporine has not been studied.
Lipid-Lowering Agents - Concomitant administration
of EVISTA with lipid-lowering agents has not been studied.
Animal Toxicology And/Or Pharmacology
The skeletal effects of raloxifene treatment were
assessed in ovariectomized rats and monkeys. In rats, raloxifene prevented
increased bone resorption and bone loss after ovariectomy. There were positive effects
of raloxifene on bone strength, but the effects varied with time. Cynomolgus
monkeys were treated with raloxifene or conjugated estrogens for 2 years. In
terms of bone cycles, this is equivalent to approximately 6 years in humans.
Raloxifene and estrogen suppressed bone turnover and increased BMD in the
lumbar spine and in the central cancellous bone of the proximal tibia. In this
animal model, there was a positive correlation between vertebral compressive
breaking force and BMD of the lumbar spine.
Histologic examination of bone from rats and monkeys
treated with raloxifene showed no evidence of woven bone, marrow fibrosis, or
mineralization defects.
These results are consistent with data from human studies
of radiocalcium kinetics and markers of bone metabolism, and are consistent
with the action of EVISTA as a skeletal antiresorptive agent.
Clinical Studies
Treatment Of Postmenopausal Osteoporosis
Effect On Fracture Incidence
The effects of EVISTA on fracture incidence and BMD in
postmenopausal women with osteoporosis were examined at 3 years in a large
randomized, placebo-controlled, double-blind, multinational osteoporosis
treatment trial (MORE). All vertebral fractures were diagnosed radiographically;
some of these fractures also were associated with symptoms (i.e., clinical
fractures). The study population consisted of 7705 postmenopausal women with
osteoporosis as defined by: a) low BMD (vertebral or hip BMD at least 2.5
standard deviations below the mean value for healthy young women) without baseline
vertebral fractures or b) one or more baseline vertebral fractures. Women
enrolled in this study had a median age of 67 years (range 31 to 80) and a
median time since menopause of 19 years.
Effect On Bone Mineral Density
EVISTA, 60 mg administered once daily, increased spine
and hip BMD by 2 to 3%. EVISTA decreased the incidence of the first vertebral
fracture from 4.3% for placebo to 1.9% for EVISTA (relative risk reduction =
55%) and subsequent vertebral fractures from 20.2% for placebo to 14.1% for
EVISTA (relative risk reduction = 30%) (see Table 4). All women in the study
received calcium (500 mg/day) and vitamin D (400 to 600 IU/day). EVISTA reduced
the incidence of vertebral fractures whether or not patients had a vertebral
fracture upon study entry. The decrease in incidence of vertebral fracture was greater
than could be accounted for by increase in BMD alone.
Table 4: Effect of EVISTA on Risk of Vertebral
Fractures
|
Number of Patients |
Absolute Risk Reduction (ARR) |
Relative Risk Reduction (95% CI) |
EVISTA |
Placebo |
Fractures diagnosed radiographically |
Patients with no baseline fracturea |
n=1401 |
n=1457 |
|
|
Number (%) of patients with ≥ 1 new vertebral fracture |
27 (1.9%) |
62 (4.3%) |
2.4% |
55% (29%, 71%) |
Patients with ≥ 1 baseline fracture2 |
n=858 |
n=835 |
|
|
Number (%) of patients with ≥ 1 new vertebral fracture |
121 (14.1%) |
169 (20.2%) |
6.1% |
30% (14%, 44%) |
Symptomatic vertebral fractures |
All randomized patients |
n=2557 |
n=2576 |
|
|
Number (%) of patients with ≥ 1 new clinical
(painful) vertebral fracture |
47 (1.8%) |
81 (3.1%) |
1.3% |
41% (17%, 59%) |
a Includes all patients with baseline and at
least one follow-up radiograph. |
The mean percentage change in BMD from baseline for
EVISTA was statistically significantly greater than for placebo at each
skeletal site (see Table 5).
Table 5: EVISTA- (60 mg Once Daily) Related Increases
in BMD for the Osteoporosis Treatment Study Expressed as Mean Percentage
Increase vs. Placebob,c
Site |
Time |
12 Months % |
24 Months % |
36 Months % |
Lumbar Spine |
2.0 |
2.6 |
2.6 |
Femoral Neck |
1.3 |
1.9 |
2.1 |
Ultradistal Radius |
NDd |
2.2 |
NDd |
Distal Radius |
NDd |
0.9 |
NDd |
Total Body |
NDd |
1.1 |
NDd |
aNote: all BMD increases were significant
(p < 0.001).
bIntent-to-treat analysis; last observation carried forward.
cAll patients received calcium and vitamin D.
dND = not done (total body and radius BMD were measured only at 24
months). |
Discontinuation from the study was required when
excessive bone loss or multiple incident vertebral fractures occurred. Such
discontinuation was statistically significantly more frequent in the placebo group
(3.7%) than in the EVISTA group (1.1%).
Bone Histology
Bone biopsies for qualitative and quantitative
histomorphometry were obtained at baseline and after 2 years of treatment.
There were 56 paired biopsies evaluable for all indices. In EVISTA-treated patients,
there were statistically significant decreases in bone formation rate per
tissue volume, consistent with a reduction in bone turnover. Normal bone
quality was maintained; specifically, there was no evidence of osteomalacia,
marrow fibrosis, cellular toxicity, or woven bone after 2 years of treatment.
Effect On Endometrium
Endometrial thickness was evaluated annually in a subset
of the study population (1781 patients) for 3 years. Placebo-treated women had
a 0.27 mm mean decrease from baseline in endometrial thickness over 3 years,
whereas the EVISTA-treated women had a 0.06 mm mean increase. Patients in the osteoporosis
treatment study were not screened at baseline or excluded for pre-existing endometrial
or uterine disease. This study was not specifically designed to detect
endometrial polyps. Over the 36 months of the study, clinically or
histologically benign endometrial polyps were reported in 17 of 1999
placebo-treated women, 37 of 1948 EVISTA-treated women, and in 31 of 2010 women
treated with raloxifene HCl 120 mg/day. There was no difference between EVISTA-
and placebo-treated women in the incidences of endometrial carcinoma, vaginal
bleeding, or vaginal discharge.
Prevention Of Postmenopausal Osteoporosis
The effects of EVISTA on BMD in postmenopausal women were
examined in three randomized, placebo-controlled, double-blind osteoporosis
prevention trials: (1) a North American trial enrolled 544 women; (2) a
European trial, 601 women; and (3) an international trial, 619 women who had undergone
hysterectomy. In these trials, all women received calcium supplementation (400
to 600 mg/day). Women enrolled in these trials had a median age of 54 years and
a median time since menopause of 5 years (less than 1 year up to 15 years
postmenopause). The majority of the women were White (93.5%). Women were
included if they had spine BMD between 2.5 standard deviations below and 2
standard deviations above the mean value for healthy young women. The mean T
scores (number of standard deviations above or below the mean in healthy young
women) for the three trials ranged from -1.01 to -0.74 for spine BMD and
included women both with normal and low BMD. EVISTA, 60 mg administered once
daily, produced increases in bone mass versus calcium supplementation alone, as
reflected by dual-energy x-ray absorptiometric (DXA) measurements of hip,
spine, and total body BMD.
Effect On Bone Mineral Density
Compared with placebo, the increases in BMD for each of
the three studies were statistically significant at 12 months and were
maintained at 24 months (see Table 6). The placebo groups lost approximately 1%
of BMD over 24 months.
Table 6: EVISTA- (60 mg Once Daily) Related Increases
in BMD for the Three Osteoporosis Prevention Studies Expressed as Mean
Percentage Increase vs. Placebob at 24 Monthsc
Site |
Study |
NAd% |
EUd% |
INTd, e% |
Total Hip |
2.0 |
2.4 |
1.3 |
Femoral Neck |
2.1 |
2.5 |
1.6 |
Trochanter |
2.2 |
2.7 |
1.3 |
Intertrochanter |
2.3 |
2.4 |
1.3 |
Lumbar Spine |
2.0 |
2.4 |
1.8 |
aNote: all BMD increases were significant
(p ≤ 0.001).
bAll patients received calcium.
cIntent-to-treat analysis; last observation carried forward.
dAbbreviations: NA = North American, EU = European, INT =
International.
e All women in the study had previously undergone hysterectomy. |
EVISTA also increased BMD compared with placebo in the
total body by 1.3% to 2.0% and in Ward's Triangle (hip) by 3.1% to 4.0%. The effects
of EVISTA on forearm BMD were inconsistent between studies. In Study EU, EVISTA
prevented bone loss at the ultradistal radius, whereas in Study NA, it did not
(see Figure 1).
Figure 1: Total hip bone mineral density mean
percentage change from baseline
Effect On Endometrium
In placebo-controlled osteoporosis prevention trials,
endometrial thickness was evaluated every 6 months (for 24 months) by
transvaginal ultrasonography (TVU). A total of 2978 TVU measurements were
collected from 831 women in all dose groups. Placebo-treated women had a 0.04
mm mean increase from baseline in endometrial thickness over 2 years, whereas
the EVISTA-treated women had a 0.09 mm mean increase. Endometrial thickness
measurements in raloxifene-treated women were indistinguishable from placebo.
There were no differences between the raloxifene and placebo groups with
respect to the incidence of reported vaginal bleeding.
Reduction In Risk Of Invasive Breast Cancer In Postmenopausal
Women With Osteoporosis
MORE Trial
The effect of EVISTA on the incidence of breast cancer
was assessed as a secondary safety endpoint in a randomized,
placebo-controlled, double-blind, multinational osteoporosis treatment trial in
postmenopausal women [see Clinical Studies]. After 4 years, EVISTA, 60
mg administered once daily, reduced the incidence of all breast cancers by 62%,
compared with placebo (HR 0.38, 95% CI 0.22-0.67). EVISTA reduced the incidence
of invasive breast cancer by 71%, compared with placebo (ARR 3.1 per 1000
women-years); this was primarily due to an 80% reduction in the incidence of
ERpositive invasive breast cancer in the EVISTA group compared with placebo.
Table 7 presents efficacy and selected safety outcomes.
CORE Trial
The effect of EVISTA on the incidence of invasive breast
cancer was evaluated for 4 additional years in a follow-up study conducted in a
subset of postmenopausal women originally enrolled in the MORE osteoporosis
treatment trial. Women were not re-randomized; the treatment assignment from
the osteoporosis treatment trial was carried forward to this study. EVISTA, 60
mg administered once daily, reduced the incidence of invasive breast cancer by
56%, compared with placebo (ARR 3.0 per 1000 women-years); this was primarily
due to a 63% reduction in the incidence of ER-positive invasive breast cancer
in the EVISTA group compared with placebo. There was no reduction in the
incidence of ER-negative breast cancer. In the osteoporosis treatment trial and
the follow-up study, there was no difference in incidence of noninvasive breast
cancer between the EVISTA and placebo groups. Table 7 presents efficacy and
selected safety outcomes.
In a subset of postmenopausal women followed for up to 8
years from randomization in MORE to the end of CORE, EVISTA, 60 mg administered
once daily, reduced the incidence of invasive breast cancer by 60% in women
assigned EVISTA (N=1355) compared with placebo (N=1286) (HR 0.40, 95% CI 0.21,
0.77; ARR 1.95 per 1000 women-years); this was primarily due to a 65% reduction
in the incidence of ER-positive invasive breast cancer in the EVISTA group
compared with placebo.
Table 7: EVISTA (60 mg Once Daily) vs. Placebo on
Outcomes in Postmenopausal Women with Osteoporosis
Outcomes |
MORE 4 years |
core3 4 years |
Placebo
(N=2576) |
EVISTA
(N=2557) |
HR (95% CI)b |
Placebo
(N=1286) |
EVISTA
(N=2725) |
HR (95% CI)b |
n |
IRb |
n |
IRb |
n |
IRb |
n |
IRb |
Invasivec breast cancer |
38 |
4.36 |
11 |
1.26 |
0.29 (0.15, 0.56)d |
20 |
5.41 |
19 |
2.43 |
0.44 (0.24, 0.83)d |
ERb,c positive |
29 |
3.33 |
6 |
0.69 |
0.20 (0.08, 0.49) |
15 |
4.05 |
12 |
1.54 |
0.37 (0.17, 0.79) |
ERb, c negative |
4 |
0.46 |
5 |
0.57 |
1.23 (0.33, 4.60) |
3 |
0.81 |
6 |
0.77 |
0.95 (0.24, 3.79) |
ERb, c unknown |
5 |
0.57 |
0 |
0.00 |
N/Ab |
2 |
0.54 |
1 |
0.13 |
N/Ab |
Noninvasivec, e breast cancer |
5 |
0.57 |
3 |
0.34 |
0.59 (0.14, 2.47) |
2 |
0.54 |
5 |
0.64 |
1.18 (0.23, 6.07) |
Clinical vertebral fractures |
107 |
12.27 |
62 |
7.08 |
0.57 (0.42, 0.78) |
N/Ab |
N/Ab |
N/Ab |
N/Ab |
N/Ab |
Death |
36 |
4.13 |
23 |
2.63 |
0.63 (0.38, 1.07) |
29 |
7.76 |
47 |
5.99 |
0.77 (0.49, 1.23) |
Death due to stroke |
6 |
0.69 |
3 |
0.34 |
0.49 (0.12, 1.98) |
1 |
0.27 |
6 |
0.76 |
2.87 (0.35, 23.80) |
Stroke |
56 |
6.42 |
43 |
4.91 |
0.76 (0.51, 1.14) |
14 |
3.75 |
49 |
6.24 |
1.67 (0.92, 3.03) |
Deep vein thrombosis |
8 |
0.92 |
20 |
2.28 |
2.50 (1.10, 5.68) |
4 |
1.07 |
17 |
2.17 |
2.03 (0.68, 6.03) |
Pulmonary embolism |
4 |
0.46 |
11 |
1.26 |
2.76 (0.88, 8.67) |
0 |
0.00 |
9 |
1.15 |
N/Ab |
Endometrial and uterine cancerf |
5 |
0.74 |
5 |
0.74 |
1.01 (0.29, 3.49) |
3 |
1.02 |
4 |
0.65 |
0.64 (0.14, 2.85) |
Ovarian cancer |
6 |
0.69 |
3 |
0.34 |
0.49 (0.12, 1.95) |
2 |
0.54 |
2 |
0.25 |
0.47 (0.07, 3.36) |
Hot flashes |
151 |
17.31 |
237 |
27.06 |
1.61 (1.31, 1.97) |
11 |
2.94 |
26 |
3.31 |
1.12 (0.55, 2.27) |
Peripheral edema |
134 |
15.36 |
164 |
18.73 |
1.23 (0.98, 1.54) |
30 |
8.03 |
61 |
7.77 |
0.96 (0.62, 1.49) |
Cholelithiasis |
45 |
5.16 |
53 |
6.05 |
1.18 (0.79, 1.75) |
12 |
3.21 |
35 |
4.46 |
1.39 (0.72, 2.67) |
aCORE was a follow-up study conducted in a
subset of 4 011 postmenopausal women who originally enrolled in MORE. Women
were not re-randomized; the treatment assignment from MORE was carried forward
to this study. At CORE enrollment, the EVISTA group included 2725 total
patients with 1355 patients who were originally assigned to raloxifene HCl 60
mg once daily and 1370 patients who were originally assigned to raloxifene HCl
120 mg at MORE randomization.
bAbbreviations: CI = confidence interval; ER = estrogen receptor; HR
= hazard ratio; IR = annual incidence rate per 1000 women; N/A = not
applicable.
cIncluded 1274 patients in placebo and 2716 patients in EVISTA who
were not diagnosed with breast cancer prior to CORE enrollment.
dp < 0.05, obtained from the log-rank test, and not adjusted for
multiple comparisons in MORE.
eAll cases were ductal carcinoma in situ.
fOnly patients with an intact uterus were included (MORE: placebo =
1999, EVISTA = 1950; CORE: placebo = 1008, EVISTA = 2138). |
RUTH Trial
The effect of EVISTA on the incidence of invasive breast
cancer was assessed in a randomized, placebo-controlled, double-blind,
multinational study in 10,101 postmenopausal women at increased risk of
coronary events. Women in this study had a median age of 67.6 years (range
55-92) and were followed for a median of 5.6 years (range 0.01-7.1).
Eighty-four percent were White, 9.8% of women reported a first-degree relative
with a history of breast cancer, and 41.4% of the women had a 5-year predicted
risk of invasive breast cancer ≥ 1.66%, based on the modified Gail model.
EVISTA, 60 mg administered once daily, reduced the
incidence of invasive breast cancer by 44% compared with placebo [absolute risk
reduction (ARR) 1.2 per 1000 women-years]; this was primarily due to a 55%
reduction in estrogen receptor (ER)-positive invasive breast cancer in the
EVISTA group compared with placebo (ARR 1.2 per 1000 women-years). There was no
reduction in ER-negative invasive breast cancer. Table 8 presents efficacy and
selected safety outcomes.
Table 8: EVISTA (60 mg Once Daily) vs. Placebo on
Outcomes in Postmenopausal Women at Increased Risk for Major Coronary Events
Outcomes |
Placeboa
(N=5057) |
EVISTAa
(N=5044) |
HR
(95% CI)b |
n |
IRb |
n |
IRb |
Invasive breast cancer |
70 |
2.66 |
40 |
1.50 |
0.56 (0.38, 0.83)c |
ERb positive |
55 |
2.09 |
25 |
0.94 |
0.45 (0.28, 0.72) |
ERb negative |
9 |
0.34 |
13 |
0.49 |
1.44 (0.61, 3.36) |
ERb unknown |
6 |
0.23 |
2 |
0.07 |
0.33 (0.07, 1.63) |
Noninvasived breast cancer |
5 |
0.19 |
11 |
0.41 |
2.17 (0.75, 6.24) |
Clinical vertebral fractures |
97 |
3.70 |
64 |
2.40 |
0.65 (0.47, 0.89) |
Death |
595 |
22.45 |
554 |
20.68 |
0.92 (0.82, 1.03) |
Death due to stroke |
39 |
1.47 |
59 |
2.20 |
1.49 (1.00, 2.24) |
Stroke |
224 |
8.60 |
249 |
9.46 |
1.10 (0.92, 1.32) |
Deep vein thrombosis |
47 |
1.78 |
65 |
2.44 |
1.37 (0.94, 1.99) |
Pulmonary embolism |
24 |
0.91 |
36 |
1.35 |
1.49 (0.89, 2.49) |
Endometrial and uterine cancere |
17 |
0.83 |
21 |
1.01 |
1.21 (0.64 - 2.30) |
Ovarian cancerf |
10 |
0.41 |
17 |
0.70 |
1.69 (0.78, 3.70) |
Hot flashes |
241 |
9.09 |
397 |
14.82 |
1.68 (1.43, 1.97) |
Peripheral edema |
583 |
22.00 |
706 |
26.36 |
1.22 (1.09, 1.36) |
Cholelithiasisg |
131 |
6.20 |
168 |
7.83 |
1.26 (1.01, 1.59) |
aNote: There were a total of 76 breast cancer
cases in the placebo group and 52 in the EVISTA group. For two cases, one in
each treatment group, invasive status was unknown.
bAbbreviations: CI = confidence interval; ER = estrogen receptor; HR
= hazard ratio; IR = annual incidence rate per 1000 women.
cp < 0.05, obtained from the log-rank test, after adjusting for the
co-primary endpoint of major coronary events.
dAll cases were ductal carcinoma in situ.
eOnly patients with an intact uterus were included(placebo = 3882,
EVISTA = 3900).
fOnly patients with at least one ovary were included (placebo = 4
606, EVISTA = 4 559).
gOnly patients with an intact gallbladder at baseline were included
placebo = 4 111, EVISTA = 4 14 4 ). |
The effect of EVISTA in reducing the incidence of
invasive breast cancer was consistent among women above or below age 65 or with
a 5-year predicted invasive breast cancer risk, based on the modified Gail
model, < 1.66%, or ≥ 1.66%.
Reduction In Risk Of Invasive Breast Cancer In Postmenopausal
Women At High Risk Of Invasive Breast Cancer
STAR Trial
The effects of EVISTA 60 mg/day versus tamoxifen 20
mg/day over 5 years on reducing the incidence of invasive breast cancer were
assessed in 19,747 postmenopausal women in a randomized, doubleblind trial
conducted in North America by the National Surgical Adjuvant Breast and Bowel
Project and sponsored by the National Cancer Institute. Women in this study had
a mean age of 58.5 years (range 35- 83), a mean 5-year predicted invasive
breast cancer risk of 4.03% (range 1.66-23.61%), and 9.1% had a history of
lobular carcinoma in situ (LCIS). More than 93% of participants were White. As
of 31 December 2005, the median time of follow-up was 4.3 years (range
0.07-6.50 years).
EVISTA was not superior to tamoxifen in reducing the
incidence of invasive breast cancer. The observed incidence rates of invasive
breast cancer were EVISTA 4.4 and tamoxifen 4.3 per 1000 women per year. The
results from a noninferiority analysis are consistent with EVISTA potentially losing
up to 35% of the tamoxifen effect on reduction of invasive breast cancer. The
effect of each treatment on invasive breast cancer was consistent when women
were compared by baseline age, history of LCIS, history of atypical
hyperplasia, 5-year predicted risk of breast cancer by the modified Gail model,
or the number of relatives with a history of breast cancer. Fewer noninvasive
breast cancers occurred in the tamoxifen group compared to the EVISTA group.
Table 9 presents efficacy and selected safety outcomes.
Table 9: EVISTA (60 mg Once Daily) vs . Tamoxifen (20
mg Once Daily) on Outcomes in Postmenopausal Women at Increased Risk for Invasive
Breast Cancer
Outcomes |
EVISTA
(N=9751) |
Tamoxifen
(N=9736) |
RR (95% CI)a |
n |
IRa |
n |
IRa |
Invasive breast cancer |
173 |
4.40 |
168 |
4.30 |
1.02 (0.82, 1.27) |
ERa positive |
115 |
2.93 |
120 |
3.07 |
0.95 (0.73, 1.24) |
ERa negative |
52 |
1.32 |
46 |
1.18 |
1.12 (0.74, 1.71) |
ERa unknown |
6 |
0.15 |
2 |
0.05 |
2.98 (0.53, 30.21) |
Noninvasive breast cancerb |
83 |
2.12 |
60 |
1.54 |
1.38 (0.98, 1.95) |
DCISa |
47 |
1.20 |
32 |
0.82 |
1.46 (0.91, 2.37) |
LCISa |
29 |
0.74 |
23 |
0.59 |
1.26 (0.70, 2.27) |
Uterine cancerc |
23 |
1.21 |
37 |
1.99 |
0.61 (0.34, 1.05) |
Endometrial hyperplasiac |
17 |
0.90 |
100 |
5.42 |
0.17 (0.09, 0.28) |
Hysterectomyc |
92 |
4.84 |
246 |
13.25 |
0.37 (0.28, 0.47) |
Ovarian cancerd |
18 |
0.66 |
14 |
0.52 |
1.27 (0.60, 2.76) |
Ischemic heart diseasee |
138 |
3.50 |
125 |
3.19 |
1.10 (0.86, 1.41) |
Stroke |
54 |
1.36 |
56 |
1.42 |
0.96 (0.65, 1.42) |
Deep vein thrombosis |
67 |
1.69 |
92 |
2.35 |
0.72 (0.52, 1.00) |
Pulmonary embolism |
38 |
0.96 |
58 |
1.47 |
0.65 (0.42, 1.00) |
Clinical vertebral fractures |
58 |
1.46 |
58 |
1.47 |
0.99 (0.68, 1.46) |
Cataractsf |
343 |
10.34 |
435 |
13.19 |
0.78 (0.68, 0.91) |
Cataract surgeryf |
240 |
7.17 |
295 |
8.85 |
0.81 (0.68, 0.96) |
Death |
104 |
2.62 |
109 |
2.76 |
0.95 (0.72, 1.25) |
Edemag |
741 |
18.66 |
664 |
16.83 |
1.11 (1.00, 1.23) |
Hot flashes |
6748 |
169.91 |
7170 |
181.71 |
0.94 (0.90, 0.97) |
aAbbreviations: CI = confidence interval; DCIS
= ductal carcinoma in situ; ER = estrogen receptor; IR = annual incidence rate
per 1000 women; LCIS = lobular carcinoma in situ; RR = risk ratio for women in
the EVISTA group compared with those in the tamoxifen group.
bOf the 60 noninvasive breast cases in the tamoxifen group, 5 were
mixed types. Of the 83 noninvasive breast cancers in the raloxifene group, 7
were mixed types.
cOnly patients with an intact uterus at baseline were included
(tamoxifen = 4 739, EVISTA = 4 715).
dOnly patients with at least one intact ovary at baseline were
included (tamoxifen = 6813, EVISTA = 6787).
eDefined as myocardial infarction, severe angina, or acute ischemic
syndromes.
fOnly patients who were free of cataracts at baseline were included
(tamoxifen = 834 2, EVISTA = 8333).
gPeripheral edema events are included in the term edema. |
Effects On Cardiovascular Disease
In a randomized, placebo-controlled, double-blind,
multinational clinical trial (RUTH) of 10,101 postmenopausal women with
documented coronary heart disease or at increased risk for coronary events, no
cardiovascular benefit was demonstrated after treatment with EVISTA 60 mg once
daily for a median follow-up of 5.6 years. No significant increase or decrease
was observed for coronary events (death from coronary causes, nonfatal
myocardial infarction, or hospitalization for an acute coronary syndrome). An
increased risk of death due to stroke after treatment with EVISTA was observed:
59 (1.2%) EVISTA-treated women died due to a stroke compared to 39 (0.8%)
placebo-treated women (2.2 versus 1.5 per 1000 women-years; hazard ratio 1.49;
95% confidence interval, 1.00-2.24; p=0.0499). The incidence of stroke did not
differ significantly between treatment groups (249 with EVISTA [4.9%] versus
224 with placebo [4.4%]; hazard ratio 1.10; 95% confidence interval 0.92-1.32;
p=0.30; 9.5 versus 8.6 per 1000 women-years) [see WARNINGS AND PRECAUTIONS].