SAT-021 Effects of E2/P4 Oral Capsules on Bone Turnover in Women with Vasomotor Symptoms

Menopausal hormone therapy slows bone turnover and reduces the risk of osteoporotic fractures. The objective of this post hoc analysis was to evaluate bone turnover markers (BTM) in the phase 3 REPLENISH trial, which evaluated vasomotor symptoms (VMS) with an oral estradiol/progesterone (E2/P4) in postmenopausal women with a uterus. Eligible women for this analysis had ≥50 moderate to severe VMS/week, <5 years since last menstrual period, and BTM measurements at baseline, and months 6 and 12. Percent changes for 3 BTM (bone specific alkaline phosphatase [BSAP], C-terminal telopeptide of type I collagen [CTX-1], and N-terminal propeptide of type I procollagen [PINP]) assessed by immunoassay methods were evaluated from baseline to months 6 and 12 for the 1/100, 0.5/100 and placebo groups. A total of 157 women (40–61 years, 69% White) were analyzed (56 for each 1/100 and 0.5/100; 45 for placebo). Mean baseline values ranged from 14.0–14.3 U/L for BSAP, 0.34–0.39 ng/mL for CTX-1, and 76.9–79.3 ng/mL for PINP. Mean differences in percent change from baseline versus placebo significantly decreased with both E2/P4 doses for all 3 BTM at months 6 and 12. Mean differences from placebo for E2/P4 at months 6/12 ranged from -8.1% to -17.8% for BSAP (all, P≤0.02), -30% to -41% for CTX-1 (all, P≤0.001), and -14% to -29% for PINP (all, P≤0.007). REPLENISH data provide support for a potential skeletal benefit of E2/P4 when used for the treatment of moderate to severe VMS.