Stroke
In the WHI estrogen plus progestin substudy, a statistically significant increased risk of stroke was reported in women 50 to 79 years of age receiving daily CE (0.625 mg) plus MPA (2.5 mg) compared to women in the same age group receiving placebo (33 versus 25 per 10,000 women-years) [see Clinical Studies (14.6)]. The increase in risk was demonstrated after the first year and persisted.1 Should a stroke occur or be suspected, estrogen plus progestin therapy should be discontinued immediately.
In the WHI estrogen-alone substudy, a statistically significant increased risk of stroke was reported in women 50 to 79 years of age receiving daily CE (0.625 mg)-alone compared to women in the same age group receiving placebo (45 versus 33 per 10,000 women-years). The increase in risk was demonstrated in year 1 and persisted [see Clinical Studies (14.6)]. Should a stroke occur or be suspected, estrogen-alone therapy should be discontinued immediately.
Subgroup analyses of women 50 to 59 years of age suggest no increased risk of stroke for those women receiving CE (0.625 mg)-alone versus those receiving placebo (18 versus 21 per 10,000 women-years).1
Coronary Heart Disease
In the WHI estrogen plus progestin substudy, there was a statistically non-significant increased risk of coronary heart disease (CHD) events (defined as nonfatal MI, silent MI, or CHD death) reported in women receiving daily CE (0.625 mg) plus MPA (2.5 mg) compared to women receiving placebo (41 versus 34 per 10,000 women-years).1 An increase in relative risk was demonstrated in year 1, and a trend toward decreasing relative risk was reported in years 2 through 5 [see Clinical Studies (14.6)].
In the WHI estrogen-alone substudy, no overall effect on CHD events was reported in women receiving estrogen-alone compared to placebo2 [see Clinical Studies (14.6)].
Subgroup analyses of women 50 to 59 years of age suggest a statistically non-significant reduction in CHD events (CE [0.625 mg]-alone compared to placebo) in women with less than 10 years since menopause (8 versus 16 per 10,000 women-years).1
In postmenopausal women with documented heart disease (n = 2,763), average 66.7 years of age, in a controlled clinical trial of secondary prevention of cardiovascular disease (Heart and Estrogen/Progestin Replacement Study [HERS]), treatment with daily CE (0.625 mg) plus MPA (2.5 mg) demonstrated no cardiovascular benefit. During an average follow-up of 4.1 years, treatment with CE plus MPA did not reduce the overall rate of CHD events in postmenopausal women with established coronary heart disease. There were more CHD events in the CE plus MPA-treated group than in the placebo group in year 1, but not during subsequent years. Two thousand, three hundred and twenty-one (2,321) women from the original HERS trial agreed to participate in an open label extension of HERS, HERS II. Average follow-up in HERS II was an additional 2.7 years, for a total of 6.8 years overall. Rates of CHD events were comparable among women in the CE plus MPA group and the placebo group in HERS, HERS II, and overall.
Venous Thromboembolism
In the WHI estrogen plus progestin substudy, a statistically significant 2-fold greater rate of VTE (DVT and PE) was reported in women receiving daily CE (0.625 mg) plus MPA (2.5 mg) compared to women receiving placebo (35 versus 17 per 10,000 women-years). Statistically significant increases in risk for both DVT (26 versus 13 per 10,000 women-years) and PE (18 versus 8 per 10,000 women-years) were also demonstrated. The increase in VTE risk was demonstrated during the first year and persisted3 [see Clinical Studies (14.6)]. Should a VTE occur or be suspected, estrogen plus progestin therapy should be discontinued immediately.
In the WHI estrogen-alone substudy, the risk of VTE was increased for women receiving daily CE (0.625 mg)-alone compared to placebo (30 versus 22 per 10,000 women-years), although only the increased risk of DVT reached statistical significance (23 versus 15 per 10,000 women-years). The increase in VTE risk was demonstrated during the first 2 years4 [see Clinical Studies (14.6)]. Should a VTE occur or be suspected, estrogen-alone therapy should be discontinued immediately.
If feasible, estrogens should be discontinued at least 4 to 6 weeks before surgery of the type associated with an increased risk of thromboembolism, or during periods of prolonged immobilization.
Breast Cancer
The most important randomized clinical trial providing information about breast cancer in estrogen plus progestin users is the WHI substudy of daily CE (0.625 mg) plus MPA (2.5 mg). After a mean follow-up of 5.6 years, the estrogen plus progestin substudy reported an increased risk of invasive breast cancer in women who took daily CE plus MPA. In this substudy, prior use of estrogen-alone or estrogen plus progestin therapy was reported by 26 percent of the women. The relative risk of invasive breast cancer was 1.24, and the absolute risk was 41 versus 33 cases per 10,000 women-years, for CE plus MPA compared with placebo. Among women who reported prior use of hormone therapy, the relative risk of invasive breast cancer was 1.86, and the absolute risk was 46 versus 25 cases per 10,000 women-years, for CE plus MPA compared with placebo. Among women who reported no prior use of hormone therapy, the relative risk of invasive breast cancer was 1.09, and the absolute risk was 40 versus 36 cases per 10,000 women-years, for CE plus MPA compared with placebo. In the same substudy, invasive breast cancers were larger, were more likely to be node positive, and were diagnosed at a more advanced stage in the CE (0.625 mg) plus MPA (2.5 mg) group compared with the placebo group. Metastatic disease was rare, with no apparent difference between the two groups. Other prognostic factors, such as histologic subtype, grade and hormone receptor status did not differ between the groups5 [see Clinical Studies (14.6)].
The most important randomized clinical trial providing information about breast cancer in estrogen-alone users is the WHI substudy of daily CE (0.625 mg)-alone. In the WHI estrogen-alone substudy, after an average follow-up of 7.1 years, daily CE (0.625 mg)-alone was not associated with an increased risk of invasive breast cancer [relative risk (RR) 0.80]6 [see Clinical Studies (14.6)].
Consistent with the WHI clinical trials, observational studies have also reported an increased risk of breast cancer for estrogen plus progestin therapy, and a smaller increased risk for estrogen-alone therapy, after several years of use. The risk increased with duration of use, and appeared to return to baseline over about 5 years after stopping treatment (only the observational studies have substantial data on risk after stopping). Observational studies also suggest that the risk of breast cancer was greater, and became apparent earlier, with estrogen plus progestin therapy as compared to estrogen-alone therapy. However, these studies have not found significant variation in the risk of breast cancer among different estrogen plus progestin combinations, doses, or routes of administration.
The use of estrogen-alone and estrogen plus progestin has been reported to result in an increase in abnormal mammograms requiring further evaluation.
All women should receive yearly breast examinations by a healthcare provider and perform monthly breast self-examinations. In addition, mammography examinations should be scheduled based on patient age, risk factors, and prior mammogram results.
Endometrial Cancer
Endometrial hyperplasia (a possible precursor of endometrial cancer) has been reported to occur at a rate of approximately 1 percent or less with PREMPRO or PREMPHASE.
An increased risk of endometrial cancer has been reported with the use of unopposed estrogen therapy in a woman with a uterus. The reported endometrial cancer risk among unopposed estrogen users is about 2 to 12 times greater than in non-users, and appears dependent on duration of treatment and on estrogen dose. Most studies show no significant increased risk associated with use of estrogens for less than 1 year. The greatest risk appears to be associated with prolonged use, with increased risks of 15- to 24-fold for 5 to 10 years or more, and this risk has been shown to persist for at least 8 to 15 years after estrogen therapy is discontinued.
Clinical surveillance of all women using estrogen-alone or estrogen plus progestin therapy is important. Adequate diagnostic measures, including directed or random endometrial sampling when indicated, should be undertaken to rule out malignancy in postmenopausal women with undiagnosed persistent or recurring abnormal genital bleeding.
There is no evidence that the use of natural estrogens results in a different endometrial risk profile than synthetic estrogens of equivalent estrogen dose. Adding a progestin to estrogen therapy in postmenopausal women has been shown to reduce the risk of endometrial hyperplasia, which may be a precursor to endometrial cancer.
Ovarian Cancer
The WHI estrogen plus progestin substudy reported a statistically non-significant increased risk of ovarian cancer. After an average follow-up of 5.6 years, the relative risk for ovarian cancer for CE plus MPA versus placebo was 1.58 (95 percent CI, 0.77–3.24). The absolute risk for CE plus MPA versus placebo was 4 versus 3 cases per 10,000 women-years.7
A meta-analysis of 17 prospective and 35 retrospective epidemiology studies found that women who used hormonal therapy for menopausal symptoms had an increased risk for ovarian cancer. The primary analysis, using case-control comparisons, included 12,110 cancer cases from the 17 prospective studies. The relative risks associated with current use of hormonal therapy was 1.41 (95% confidence interval [CI] 1.32 to 1.50); there was no difference in the risk estimates by duration of the exposure (less than 5 years [median of 3 years] vs. greater than 5 years [median of 10 years] of use before the cancer diagnosis). The relative risk associated with combined current and recent use (discontinued use within 5 years before cancer diagnosis) was 1.37 (95% CI 1.27–1.48), and the elevated risk was significant for both estrogen-alone and estrogen plus progestin products. The exact duration of hormone therapy use associated with an increased risk of ovarian cancer, however, is unknown.
Genitourinary System
Abnormal uterine bleeding, dysmenorrhea or pelvic pain, increase in size of uterine leiomyomata, vaginitis, vaginal candidiasis, amenorrhea, changes in cervical secretion, ovarian cancer, endometrial hyperplasia, endometrial cancer.
Breasts
Tenderness, enlargement, pain, nipple discharge, galactorrhea, fibrocystic breast changes, breast cancer.
Cardiovascular
Deep and superficial venous thrombosis, pulmonary embolism, superficial thrombophlebitis, myocardial infarction, stroke, increase in blood pressure.
Gastrointestinal
Nausea, vomiting, abdominal pain, bloating, cholestatic jaundice, increased incidence of gallbladder disease, pancreatitis, changes in appetite, ischemic colitis.
Skin
Chloasma or melasma that may persist when drug is discontinued, erythema multiforme, erythema nodosum, loss of scalp hair, hirsutism, pruritus, urticaria, rash, acne.
Eyes
Retinal vascular thrombosis, intolerance of contact lenses.
Central Nervous System
Headache, migraine, dizziness, mental depression, exacerbation of chorea, mood disturbances, anxiety, irritability, exacerbation of epilepsy, dementia, growth potentiation of benign meningioma.
Miscellaneous
Increase or decrease in weight, arthralgia, glucose intolerance, edema, changes in libido, exacerbation of asthma, increased triglycerides, hypersensitivity.
Additional postmarketing adverse reactions have been reported in patients receiving other forms of hormone therapy.
The Women's Health Initiative Studies
In the WHI estrogen plus progestin substudy (daily CE [0.625 mg] plus MPA [2.5 mg] versus placebo), there was a higher relative risk of nonfatal stroke and invasive breast cancer in women greater than 65 years of age [see Clinical Studies (14.6)].
In the WHI estrogen-alone substudy (daily CE [0.625 mg]-alone versus placebo), there was a higher relative risk of stroke in women greater than 65 years of age [see Clinical Studies (14.6)].
The Women's Health Initiative Memory Study
In the WHIMS ancillary studies of postmenopausal women 65 to 79 years of age, there was an increased risk of developing probable dementia in women receiving estrogen plus progestin or estrogen-alone when compared to placebo [see Warnings and Precautions (5.3), and Clinical Studies (14.7)].
Since both ancillary studies were conducted in women 65 to 79 years of age, it is unknown whether these findings apply to younger postmenopausal women8 [see Warnings and Precautions (5.3), and Clinical Studies (14.7)].
PREMPHASE
Each maroon Premarin tablets for oral administration contain 0.625 mg of conjugated estrogens and the following inactive ingredients: calcium phosphate tribasic, carnauba wax, hydroxypropyl cellulose, microcrystalline cellulose, powdered cellulose, hypromellose, lactose monohydrate, magnesium stearate, polyethylene glycol, sucrose, titanium dioxide, propylene glycol, FD&C Blue No. 2, and FD&C Red No. 40. These tablets comply with USP Dissolution Test 5.
Each light-blue tablet for oral administration contains 0.625 mg of conjugated estrogens, 5 mg of medroxyprogesterone acetate, and the following inactive ingredients: calcium phosphate tribasic, carnauba wax, Eudragit NE 30D, hydroxypropyl cellulose, hypromellose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, polyethylene glycol, sucrose, titanium dioxide, triethyl citrate, FD&C Blue No. 2, black iron oxide, and propylene glycol.
PREMPRO
| Tablet Strength | Tablet Color Contains |
|---|
| 0.3 mg/1.5 mg | Yellow iron oxide and black iron oxide |
| 0.45 mg/1.5 mg | Yellow iron oxide and black iron oxide |
| 0.625 mg/2.5 mg | Red iron oxide, yellow iron oxide, and black iron oxide |
| 0.625 mg/5 mg | FD&C Blue No. 2 and black iron oxide |
PREMPHASE
| Tablet Strength | Tablet Color Contains |
|---|
| 0.625 mg | FD&C Blue No. 2 and FD&C Red No. 40 |
| 0.625 mg/5 mg | FD&C Blue No. 2 and black iron oxide |
Absorption
PREMPRO and PREMPHASE contain a formulation of medroxyprogesterone acetate (MPA) that is immediately released and conjugated estrogens that are slowly released over several hours. Conjugated estrogens are water-soluble and are well-absorbed from the gastrointestinal tract after release from the drug formulation. MPA is well absorbed from the gastrointestinal tract. Table 3 and Table 4 summarize the mean pharmacokinetic parameters for select unconjugated and conjugated estrogens and medroxyprogesterone acetate following administration of PREMPRO to healthy, postmenopausal women.
TABLE 3: PHARMACOKINETIC PARAMETERS FOR UNCONJUGATED AND CONJUGATED ESTROGENS (CE) AND MEDROXYPROGESTERONE ACETATE (MPA)| DRUG | 2 × 0.625 mg CE/2.5 mg MPA Combination Tablets (n = 54) | 2 × 0.625 mg CE/5 mg MPA Combination Tablets (n = 51) |
|---|
BA* = Baseline adjusted Cmax = peak plasma concentration tmax = time peak concentration occurs t1/2 = apparent terminal-phase disposition half-life (0.693/λz) AUC = total area under the concentration-time curve |
PK Parameter Arithmetic Mean (%CV) | Cmax (pg/mL) | tmax (h) | t1/2 (h) | AUC (pg∙h/mL) | Cmax (pg/mL) | tmax (h) | t1/2 (h) | AUC (pg∙h/mL) |
| Unconjugated Estrogens |
| Estrone | 175 (23) | 7.6 (24) | 31.6 (23) | 5358 (34) | 124 (43) | 10 (35) | 62.2 (137) | 6303 (40) |
| BA* -Estrone | 159 (26) | 7.6 (24) | 16.9 (34) | 3313 (40) | 104 (49) | 10 (35) | 26.0 (100) | 3136 (51) |
| Equilin | 71 (31) | 5.8 (34) | 9.9 (35) | 951 (43) | 54 (43) | 8.9 (34) | 15.5 (53) | 1179 (56) |
PK Parameter Arithmetic Mean (%CV) | Cmax (ng/mL) | tmax (h) | t1/2 (h) | AUC (ng∙h/mL) | Cmax (ng/mL) | tmax (h) | t1/2 (h) | AUC (ng∙h/mL) |
| Conjugated Estrogens |
| Total Estrone | 6.6 (38) | 6.1 (28) | 20.7 (34) | 116 (59) | 6.3 (48) | 9.1 (29) | 23.6 (36) | 151 (42) |
| BA* -Total Estrone | 6.4 (39) | 6.1 (28) | 15.4 (34) | 100 (57) | 6.2 (48) | 9.1 (29) | 20.6 (35) | 139 (40) |
| Total Equilin | 5.1 (45) | 4.6 (35) | 11.4 (25) | 50 (70) | 4.2 (52) | 7.0 (36) | 17.2 (131) | 72 (50) |
PK Parameter Arithmetic Mean (%CV) | Cmax (ng/mL) | tmax (h) | t1/2 (h) | AUC (ng∙h/mL) | Cmax (ng/mL) | tmax (h) | t1/2 (h) | AUC (ng∙h/mL) |
| Medroxyprogesterone Acetate |
| MPA | 1.5 (40) | 2.8 (54) | 37.6 (30) | 37 (30) | 4.8 (31) | 2.4 (50) | 46.3 (39) | 102 (28) |
TABLE 4. PHARMACOKINETIC PARAMETERS FOR UNCONJUGATED AND CONJUGATED ESTROGENS (CE) AND MEDROXYPROGESTERONE ACETATE (MPA)| DRUG | 4 × 0.45 mg CE/1.5 mg MPA Combination (n = 65) |
|---|
BA* = Baseline adjusted Cmax = peak plasma concentration tmax = time peak concentration occurs t1/2 = apparent terminal-phase disposition half-life (0.693/λz) AUC = total area under the concentration-time curve |
PK Parameter Arithmetic Mean (%CV) | Cmax (pg/mL) | tmax (h) | t1/2 (h) | AUC (pg∙h/mL) |
| Unconjugated Estrogens |
| Estrone | 149 (35) | 8.9 (35) | 37.5 (35) | 6641 (39) |
| BA* -Estrone | 130 (40) | 8.9 (35) | 21.2 (35) | 3799 (47) |
| Equilin | 83 (38) | 8.3 (48) | 15.9 (44) | 1889 (40) |
PK Parameter Arithmetic Mean (%CV) | Cmax (ng/mL) | tmax (h) | t1/2 (h) | AUC (ng∙h/mL) |
| Conjugated Estrogens |
| Total Estrone | 5.4 (49) | 7.9 (48) | 22.4 (53) | 119 (48) |
| BA* -Total Estrone | 5.2 (48) | 7.9 (48) | 15.1 (29) | 100 (47) |
| Total Equilin | 4.3 (42) | 6.5 (45) | 11.6 (31) | 74 (48) |
PK Parameter Arithmetic Mean (%CV) | Cmax (ng/mL) | tmax (h) | t1/2 (h) | AUC (ng∙h/mL) |
| Medroxyprogesterone Acetate |
| MPA | 0.7 (66) | 2.0 (52) | 26.2 (35) | 5.0 (61) |
Food-Effect: Single dose studies in healthy, postmenopausal women were conducted to investigate any potential drug interaction when PREMPRO or PREMPHASE is administered with a high-fat breakfast. Administration with food decreased the Cmax of total estrone by 18 to 34 percent and increased total equilin Cmax by 38 percent compared to the fasting state, with no other effect on the rate or extent of absorption of other conjugated or unconjugated estrogens. Administration with food approximately doubles MPA Cmax and increases MPA AUC by approximately 20 to 30 percent.
Dose Proportionality: The Cmax and AUC values for MPA observed in two separate pharmacokinetic studies conducted with 2 PREMPRO 0.625 mg/2.5 mg or 2 PREMPRO or PREMPHASE 0.625 mg/5 mg tablets exhibited nonlinear dose proportionality; doubling the MPA dose from 2 × 2.5 to 2 × 5 mg increased the mean Cmax and AUC by 3.2- and 2.8-fold, respectively.
The dose proportionality of estrogens and medroxyprogesterone acetate was assessed by combining pharmacokinetic data across another two studies totaling 61 healthy, postmenopausal women. Single conjugated estrogens doses of 2 × 0.3 mg, 2 × 0.45 mg, or 2 × 0.625 mg were administered either alone or in combination with medroxyprogesterone acetate doses of 2 × 1.5 mg or 2 × 2.5 mg. Most of the estrogen components demonstrated dose proportionality; however, several estrogen components did not. Medroxyprogesterone acetate pharmacokinetic parameters increased in a dose-proportional manner.
Distribution
The distribution of exogenous estrogens is similar to that of endogenous estrogens. Estrogens are widely distributed in the body and are generally found in higher concentrations in the sex hormone target organs. Estrogens circulate in the blood largely bound to SHBG and albumin. MPA is approximately 90 percent bound to plasma proteins, but does not bind to SHBG.
Metabolism
Exogenous estrogens are metabolized in the same manner as endogenous estrogens. Circulating estrogens exist in a dynamic equilibrium of metabolic interconversions. These transformations take place mainly in the liver. Estradiol is converted reversibly to estrone, and both can be converted to estriol, which is a major urinary metabolite. Estrogens also undergo enterohepatic recirculation via sulfate and glucuronide conjugation in the liver, biliary secretion of conjugates into the intestine, and hydrolysis in the intestine followed by reabsorption. In postmenopausal women, a significant portion of the circulating estrogens exists as sulfate conjugates, especially estrone sulfate, which serves as a circulating reservoir for the formation of more active estrogens. Metabolism and elimination of MPA occur primarily in the liver via hydroxylation, with subsequent conjugation and elimination in the urine.
Excretion
Estradiol, estrone, and estriol are excreted in the urine along with glucuronide and sulfate conjugates. Most metabolites of MPA are excreted as glucuronide conjugates, with only minor amounts excreted as sulfates.
Use in Specific Populations
No pharmacokinetic studies were conducted in specific populations, including patients with renal or hepatic impairment.
Health and Osteoporosis, Progestin and Estrogen (HOPE) Study
The HOPE study was a double-blind, randomized, placebo/active-drug-controlled, multicenter study of healthy postmenopausal women with an intact uterus. Subjects (mean age 53.3 ± 4.9 years) were 2.3 ± 0.9 years on average since menopause and took one 600 mg tablet of elemental calcium (Caltrate™) daily. Subjects were not given Vitamin D supplements. They were treated with PREMPRO 0.625 mg/2.5 mg, 0.45 mg/1.5 mg or 0.3 mg/1.5 mg, comparable doses of Premarin alone, or placebo. Prevention of bone loss was assessed by measurement of bone mineral density (BMD), primarily at the anteroposterior lumbar spine (L2 to L4). Secondarily, BMD measurements of the total body, femoral neck, and trochanter were also analyzed. Serum osteocalcin, urinary calcium, and N-telopeptide were used as bone turnover markers (BTM) at cycles 6, 13, 19, and 26.
Intent-to-treat subjects
All active treatment groups showed significant differences from placebo in each of the four BMD endpoints. These significant differences were seen at cycles 6, 13, 19, and 26.
The percent changes from baseline to final evaluation are shown in Table 9.
TABLE 9: PERCENT CHANGE IN BONE MINERAL DENSITY: COMPARISON BETWEEN ACTIVE AND PLACEBO GROUPS IN THE INTENT-TO-TREAT POPULATION, LOCF| Region Evaluated Treatment Group Identified by dosage (mg/mg) of Premarin/MPA or placebo. | No. of Subjects | Baseline (g/cm2) Mean ± SD | Change from Baseline (%) Adjusted Mean ± SE | p-Value vs. Placebo |
|---|
| L2 to L4 BMD | | | | |
| 0.625/2.5 | 81 | 1.14 ± 0.16 | 3.28 ± 0.37 | <0.001 |
| 0.45/1.5 | 89 | 1.16 ± 0.14 | 2.18 ± 0.35 | <0.001 |
| 0.3/1.5 | 90 | 1.14 ± 0.15 | 1.71 ± 0.35 | <0.001 |
| Placebo | 85 | 1.14 ± 0.14 | -2.45 ± 0.36 | |
| Total body BMD | | | | |
| 0.625/2.5 | 81 | 1.14 ± 0.08 | 0.87 ± 0.17 | <0.001 |
| 0.45/1.5 | 89 | 1.14 ± 0.07 | 0.59 ± 0.17 | <0.001 |
| 0.3/1.5 | 91 | 1.13 ± 0.08 | 0.60 ± 0.16 | <0.001 |
| Placebo | 85 | 1.13 ± 0.08 | -1.50 ± 0.17 | |
| Femoral neck BMD | | | | |
| 0.625/2.5 | 81 | 0.89 ± 0.14 | 1.62 ± 0.46 | <0.001 |
| 0.45/1.5 | 89 | 0.89 ± 0.12 | 1.48 ± 0.44 | <0.001 |
| 0.3/1.5 | 91 | 0.86 ± 0.11 | 1.31 ± 0.43 | <0.001 |
| Placebo | 85 | 0.88 ± 0.14 | -1.72 ± 0.45 | |
| Femoral trochanter BMD | | | | |
| 0.625/2.5 | 81 | 0.77 ± 0.14 | 3.35 ± 0.59 | 0.002 |
| 0.45/1.5 | 89 | 0.76 ± 0.12 | 2.84 ± 0.57 | 0.011 |
| 0.3/1.5 | 91 | 0.76 ± 0.12 | 3.93 ± 0.56 | <0.001 |
| Placebo | 85 | 0.75 ± 0.12 | 0.81 ± 0.58 | |
Figure 3 shows the cumulative percentage of subjects with percent changes from baseline in spine BMD equal to or greater than the percent change shown on the x-axis.
FIGURE 3. CUMULATIVE PERCENT OF SUBJECTS WITH CHANGES FROM BASELINE IN SPINE BMD OF GIVEN MAGNITUDE OR GREATER IN PREMARIN/MPA AND PLACEBO GROUPSThe mean percent changes from baseline in L2 to L4 BMD for women who completed the bone density study are shown with standard error bars by treatment group in Figure 4. Significant differences between each of the PREMPRO dosage groups and placebo were found at cycles 6, 13, 19, and 26.
FIGURE 4. ADJUSTED MEAN (SE) PERCENT CHANGE FROM BASELINE AT EACH CYCLE IN SPINE BMD: SUBJECTS COMPLETING IN PREMARIN/MPA GROUPS AND PLACEBOThe bone turnover markers, serum osteocalcin and urinary N-telopeptide, significantly decreased (p < 0.001) in all active-treatment groups at cycles 6, 13, 19, and 26 compared with the placebo group. Larger mean decreases from baseline were seen with the active groups than with the placebo group. Significant differences from placebo were seen less frequently in urine calcium; only with PREMPRO 0.625 mg/2.5 mg and 0.45 mg/1.5 mg were there significantly larger mean decreases than with placebo at 3 or more of the 4 time points.
WHI Estrogen Plus Progestin Substudy
The WHI estrogen plus progestin substudy was stopped early. According to the predefined stopping rule, after an average follow-up of 5.6 years of treatment, the increased risk of invasive breast cancer and cardiovascular events exceeded the specified benefits included in the "global index." The absolute excess risk of events included in the "global index" was 19 per 10,000 women-years.
For those outcomes included in the WHI "global index" that reached statistical significance after 5.6 years of follow-up, the absolute excess risks per 10,000 women-years in the group treated with CE plus MPA were 7 more CHD events, 8 more strokes, 10 more PEs, and 8 more invasive breast cancers, while the absolute risk reductions per 10,000 women-years were 6 fewer colorectal cancers and 5 fewer hip fractures.
Results of the CE plus MPA substudy, which included 16,608 women (average 63 years of age, range 50 to 79; 83.9 percent White, 6.8 percent Black, 5.4 percent Hispanic, 3.9 percent Other) are presented in Table 10. These results reflect centrally adjudicated data after an average follow-up of 5.6 years.
TABLE 10: Relative and Absolute Risk Seen in the Estrogen Plus Progestin Substudy of WHI at an Average of 5.6 YearsAdapted from numerous WHI publications. WHI publications can be viewed at www.nhlbi.nih.gov/whi.
,Results are based on centrally adjudicated data.
| Relative Risk CE/MPA vs. Placebo (95% nCINominal confidence intervals unadjusted for multiple looks and multiple comparisons. ) | CE/MPA n = 8,506 | Placebo n = 8,102 |
|---|
| Event | | Absolute Risk per 10,000 Women-Years |
|---|
| CHD events | 1.23 (0.99–1.53) | 41 | 34 |
| Non-fatal MI | 1.28 (1.00–1.63) | 31 | 25 |
| CHD death | 1.10 (0.70–1.75) | 8 | 8 |
| All Strokes | 1.31 (1.03–1.68) | 33 | 25 |
| Ischemic stroke | 1.44 (1.09–1.90) | 26 | 18 |
| Deep vein thrombosis Not included in "global index." | 1.95 (1.43–2.67) | 26 | 13 |
| Pulmonary embolism | 2.13 (1.45–3.11) | 18 | 8 |
| Invasive breast cancer Includes metastatic and non-metastatic breast cancer, with the exception of in situ breast cancer. | 1.24 (1.01–1.54) | 41 | 33 |
| Colorectal cancer | 0.61 (0.42–0.87) | 10 | 16 |
| Endometrial cancer | 0.81 (0.48–1.36) | 6 | 7 |
| Cervical cancer | 1.44 (0.47–4.42) | 2 | 1 |
| Hip fracture | 0.67 (0.47–0.96) | 11 | 16 |
| Vertebral fractures | 0.65 (0.46–0.92) | 11 | 17 |
| Lower arm/wrist fractures | 0.71 (0.59–0.85) | 44 | 62 |
| Total fractures | 0.76 (0.69–0.83) | 152 | 199 |
| Overall Mortality All deaths, except from breast or colorectal cancer, definite or probable CHD, PE or cerebrovascular disease. | 1.00 (0.83–1.19) | 52 | 52 |
| Global Index A subset of the events was combined in a "global index" defined as the earliest occurrence of CHD events, invasive breast cancer, stroke, pulmonary embolism, colorectal cancer, hip fracture, or death due to other causes. | 1.13 (1.02–1.25) | 184 | 165 |
Timing of the initiation of estrogen plus progestin therapy relative to the start of menopause may affect the overall risk benefit profile. The WHI estrogen plus progestin substudy stratified by age showed in women 50 to 59 years of age, a non-significant trend toward reduced risk for overall mortality [hazard ratio (HR) 0.69 (95 percent CI, 0.44–1.07)].
WHI Estrogen-Alone Substudy
The WHI estrogen-alone substudy was stopped early because an increased risk of stroke was observed, and it was deemed that no further information would be obtained regarding the risks and benefits of estrogen-alone in predetermined primary endpoints.
Results of the estrogen-alone substudy, which included 10,739 women (average 63 years of age, range 50 to 79; 75.3 percent White, 15.1 percent Black, 6.1 percent Hispanic, 3.6 percent Other) after an average follow-up of 7.1 years, are presented in Table 11.
Table 11: Relative and Absolute Risk Seen in the Estrogen-Alone Substudy of WHIAdapted from numerous WHI publications. WHI publications can be viewed at www.nhlbi.nih.gov/whi.
| Relative Risk CE vs. Placebo (95% nCINominal confidence intervals unadjusted for multiple looks and multiple comparisons. ) | CE n = 5,310 | Placebo n = 5,429 |
|---|
| Event | | Absolute Risk per 10,000 Women-Years |
|---|
| CHD events Results are based on centrally adjudicated data for an average follow-up of 7.1 years. | 0.95 (0.78–1.16) | 54 | 57 |
| Non-fatal MI | 0.91 (0.73–1.14) | 40 | 43 |
| CHD death | 1.01 (0.71–1.43) | 16 | 16 |
| All Strokes | 1.33 (1.05–1.68) | 45 | 33 |
| Ischemic stroke | 1.55 (1.19–2.01) | 38 | 25 |
| Deep vein thrombosis, Not included in "global index." | 1.47 (1.06–2.06) | 23 | 15 |
| Pulmonary embolism | 1.37 (0.90–2.07) | 14 | 10 |
| Invasive breast cancer | 0.80 (0.62–1.04) | 28 | 34 |
| Colorectal cancer Results are based on an average follow-up of 6.8 years. | 1.08 (0.75–1.55) | 17 | 16 |
| Hip fracture | 0.65 (0.45–0.94) | 12 | 19 |
| Vertebral fractures, | 0.64 (0.44–0.93) | 11 | 18 |
| Lower arm/wrist fractures, | 0.58 (0.47–0.72) | 35 | 59 |
| Total fractures, | 0.71 (0.64–0.80) | 144 | 197 |
| Death due to other causes, All deaths, except from breast or colorectal cancer, definite or probable CHD, PE or cerebrovascular disease. | 1.08 (0.88–1.32) | 53 | 50 |
| Overall mortality, | 1.04 (0.88–1.22) | 79 | 75 |
| Global Index A subset of the events was combined in a "global index" defined as the earliest occurrence of CHD events, invasive breast cancer, stroke, pulmonary embolism, colorectal cancer, hip fracture, or death due to other causes. | 1.02 (0.92–1.13) | 206 | 201 |
For those outcomes included in the WHI "global index" that reached statistical significance, the absolute excess risk per 10,000 women-years in the group treated with CE-alone was 12 more strokes while the absolute risk reduction per 10,000 women-years was 7 fewer hip fractures.9 The absolute excess risk of events included in the "global index" was a non-significant 5 events per 10,000 women-years. There was no difference between the groups in terms of all-cause mortality.
No overall difference for primary CHD events (nonfatal MI, silent MI and CHD death) and invasive breast cancer incidence in women receiving CE-alone compared with placebo was reported in final centrally adjudicated results from the estrogen-alone substudy, after an average follow up of 7.1 years.
Centrally adjudicated results for stroke events from the estrogen-alone substudy, after an average follow-up of 7.1 years, reported no significant difference in distribution of stroke subtype or severity, including fatal strokes, in women receiving CE-alone compared to placebo. Estrogen-alone increased the risk for ischemic stroke, and this excess risk was present in all subgroups of women examined.10
Timing of the initiation of estrogen-alone therapy relative to the start of menopause may affect the overall risk benefit profile. The WHI estrogen-alone substudy, stratified by age, showed in women 50 to 59 years of age a non-significant trend toward reduced risk for CHD [HR 0.63 (95 percent CI, 0.36–1.09)] and overall mortality [HR 0.71 (95 percent CI, 0.46–1.11)].
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LAB-0502-9.0