Prometrium Drug Information

Effects on the endometrium In a randomized, double-blind clinical trial, 358 postmenopausal women, each with an intact uterus, received treatment for up to 36 months. The treatment groups were: PROMETRIUM ® (progesterone, USP) Capsules at the dose of 200 mg per day for 12 days per 28-day cycle in combination with conjugated estrogens 0.625 mg per day (n=120); conjugated estrogens 0.625 mg per day only (n=119); or placebo (n=119). The subjects in all three treatment groups were primarily Caucasian women (87 percent or more of each group).

The results for the incidence of endometrial hyperplasia in women receiving up to 3 years of treatment are shown in Table 3. A comparison of the PROMETRIUM Capsules plus conjugated estrogens treatment group to the conjugated estrogens only group showed a significantly lower rate of hyperplasia (6 percent combination product versus 64 percent estrogen alone) in the PROMETRIUM Capsules plus conjugated estrogens treatment group throughout 36 months of treatment. TABLE 3.

This figure illustrates graphically that the proportion of patients with hyperplasia was significantly greater for the conjugated estrogens group (64 percent) compared to the conjugated estrogens plus PROMETRIUM Capsules group (6 percent). Figure 1. Time to Hyperplasia in Women Receiving up to 36 Months of Treatment The discontinuation rates due to hyperplasia over the 36 months of treatment are as shown in Table 4.

For any degree of hyperplasia, the discontinuation rate for patients who received conjugated estrogens plus PROMETRIUM Capsules was similar to that of the placebo only group, while the discontinuation rate for patients who received conjugated estrogens alone was significantly higher. Women who permanently discontinued treatment due to hyperplasia were similar in demographics to the overall study population. TABLE 4.

Discontinuation Rate Due to Hyperplasia Over 36 Months of Treatment 0 0 Figure 1 Effects on secondary amenorrhea In a single-center, randomized, double-blind clinical study that included premenopausal women with secondary amenorrhea for at least 90 days, administration of 10 days of PROMETRIUM ® (progesterone, USP) Capsules therapy resulted in 80 percent of women experiencing withdrawal bleeding within 7 days of the last dose of PROMETRIUM Capsules, 300 mg per day (n=20), compared to 10 percent of women experiencing withdrawal bleeding in the placebo group (n=21). In a multicenter, parallel-group, open label, postmarketing dosing study that included premenopausal women with secondary amenorrhea for at least 90 days, administration of 10 days of PROMETRIUM Capsules during two 28-day treatment cycles, 300 mg per day (n=107) or 400 mg per day (n=99), resulted in 73.8 percent and 76.8 percent of women, respectively, experiencing withdrawal bleeding. The rate of secretory transformation was evaluated in a multicenter, randomized, double-blind clinical study in estrogen-primed postmenopausal women.

PROMETRIUM Capsules administered orally for 10 days at 400 mg per day (n=22) induced complete secretory changes in the endometrium in 45 percent of women compared to 0 percent in the placebo group (n=23). A second multicenter, parallel-group, open label postmarketing dosing study in premenopausal women with secondary amenorrhea for at least 90 days also evaluated the rate of secretory transformation. All subjects received daily oral conjugated estrogens over 3 consecutive 28-day treatment cycles and PROMETRIUM Capsules, 300 mg per day (n=107) or 400 mg per day (n=99) for 10 days of each treatment cycle.

The rate of complete secretory transformation was 21.5 percent and 28.3 percent, respectively. Women's Health Initiative Estrogen Plus Progestin Trial The WHI estrogen plus progestin trial enrolled predominantly healthy postmenopausal women to assess the risks and benefits of daily oral CE (0.625 mg) in combination with MPA (2.5 mg) compared to placebo in the prevention of certain chronic diseases. The primary endpoint was the incidence of CHD (defined as nonfatal MI, silent MI and CHD death), with invasive breast cancer as the primary adverse outcome.

A "global index" included the earliest occurrence of CHD, invasive breast cancer, stroke, PE, endometrial cancer colorectal cancer, hip fracture, or death due to other causes. This trial did not evaluate the effects of CE plus MPA on menopausal symptoms. The WHI estrogen plus progestin trial was stopped early.

After an average follow-up of 5.6 years of treatment, the increased risk of invasive breast cancer crossed the predefined stopping threshold. The global index was supportive of a finding of overall harm. The absolute excess risk of events included in the global index was 19 per 10,000 women-years.

These results reflect centrally adjudicated data after an average follow-up of 5.6 years. TABLE 5. Relative and Absolute Risk Seen in the WHI Estrogen Plus Progestin Trial at an Average of 5.6 Years Adapted from numerous WHI publications.

WHI publications can be viewed at www.nhlbi.nih.gov/whi., Results are based on centrally adjudicated data. Timing of the initiation of estrogen plus progestin therapy relative to the start of menopause may affect the overall risk benefit profile. The results of the WHI estrogen plus progestin trial in women 50 to 59 years of age (N=2,837 for CE/MPA; N=2,683 for placebo) are shown in Table 6.

Table 6. Relative Risk and Risk Difference Observed Among Women 50-59 Years of Age in the WHI Estrogen Plus Progestin Trial at an Average of 5.6 Adapted from 2013 WHI trial (CE/MPA n=2,837; placebo=2,683). The absolute risk of probable dementia for CE plus MPA versus placebo was 45 versus 22 per 10,000 women-years.

Probable dementia as defined in this study included Alzheimer's disease (AD), vascular dementia (VaD) and mixed type (having features of both AD and VaD). The most common classification of probable dementia in the treatment group and the placebo group was AD. Since the ancillary study was conducted in women 65 to 79 years of age, it is unknown whether these findings apply to younger postmenopausal women. (See PRECAUTIONS, Geriatric Use.)