To ensure the comparability of the two populations, we identified patients in the placebo group with the same FRAX® score, i.e. 10-year probability of major osteoporotic fracture, at baseline (year https://www.selleckchem.com/products/PD-0332991.html 0) as the 10-year population at entry to the extension study (year 6) using a modified case–control analysis with
a ratio of two patients from TROPOS to one patient from the extension study. This FRAX®-matched placebo population comprised 458 patients. The Greedy’s algorithm (an optimal version of the k-means method) with six clusters was used. A P value of 0.05 or less was considered significant. Statistical analysis was performed using SAS/PC software version 9.1. Results Patient characteristics The 10-year extension study was performed in 36 centers in eight European countries and Australia. Out of the 2055 patients who entered the extension study at 5 years, 1420 (69%) completed the 3-year treatment period to 8 years. A total of 603 patients accepted to participate in the 2-year prolongation of the extension study to 10 years, of whom 237 had been treated with strontium ranelate for 8 years (i.e. the 10-year population, Fig. 1). The 10-year population consisted of 233 patients (56 from SOTI and 177 from TROPOS; four patients excluded since they did not take the study treatment). The characteristics of the 10-year population at year 0 were similar to those of the two main study populations at
year 0 (Table 1). Table 1 Baseline characteristics at year 0 Pooled SOTI and TROPOSa (n = 6503) 10-Year population (n = 237) Age (years) 75.2 ± 6.4 72.0 ± 5.4 Body mass index (kg/m2) 25.65 ± 4.09 25.80 ± 3.82 Time since menopause (years) 27.4 ± 8.3 Volasertib 23.65 ± 6.81 ≥ 1 Prevalent nonvertebral fracture, n (%) 2365 (36) 103 (44) ≥ 1 Prevalent vertebral fracture, n (%) 2857 (44) 100 (45) Lumbar BMD (g/cm2)
0.781 ± 0.152 0.755 ± 0.136 T-score −3.00 ± 1.52 −3.266 ± 1.420 Femoral neck BMD (g/cm2) 0.561 ± 0.075 0.576 ± 0.063 T-score −3.06 ± 0.67 −2.946 ± 0.566 Total hip BMD (g/cm2) 0.658 ± 0.102 0.688 ± 0.089 T-score −2.64 ± 1.00 −2.344 ± 0.876 BMD bone mineral density aRandomized set SOTI and TROPOS excluding the 10-year population The mean persistence Rutecarpine with strontium ranelate in the 10-year population was 117.8 ± 6.1 months (i.e. 9 years and 9 months); the mean compliance was 89.4 ± 12.6%. Blood strontium values reached a plateau after 3 months of treatment. Mean values of blood strontium ranged from 136.1 ± 89.3 to 158.8 ± 105.7 μmol/L and were consistent with good exposure to the treatment over 10 years. Fractures The cumulative incidence of new fracture in the 10-year population in years 6 to 10 was similar to the cumulative incidence in years 0 to 5 (vertebral fracture: 20.6 ± 3.0% versus 18.5 ± 2.6%, respectively, P = 1.00; non-vertebral fracture: 13.7 ± 2.3% versus 12.9 ± 2.2%, P = 0.672; and any osteoporotic fracture: 30.3 ± 3.1% versus 27.5 ± 2.9%, P = 0.734) (Fig. 2).