PHILADELPHIA — Teriparatide appears to increase bone mineral density regardless of prior antiresorptive therapy response, said Dr. Barbara Obermayer-Pietsch at the annual meeting of the American Society for Bone and Mineral Research.
Dr. Obermayer-Pietsch of Universitätsklinik für Innere Medizin in Graz, Austria, and her colleagues looked at bone mineral density (BMD) changes at the lumbar spine, femoral neck, and total hip in 503 women who received teriparatide (Forteo) for 2 years.
The women were grouped by exposure and response to previous antiresorptive therapy (no prior therapy, adequate response to prior therapy, and inadequate response to prior therapy).
Inadequate response was defined as at least one new clinical fragility fracture after 12 months of therapy, a T score less than or equal to -3 after 24 months of therapy, or a BMD decrease of at least 3.5% after more than 24 months of therapy.
In all, 84 women were antiresorptive-treatment naive, 109 were adequate responders, and 310 were inadequate responders.
In terms of previous treatment, 86% of bisphosphonate users in the adequate-response group and 93% of bisphosphonate users in the inadequate-response group used alendronate, risedronate, or etidronate.
The remaining patients used selective estrogen-receptor modulators, hormone therapy, or vitamin supplements.
“We found an immediate and continuous increase of BMD at the lumbar spine in all groups. However, this was more pronounced in the treatment-naive group,” said Dr. Obermayer-Pietsch.
The antiresorptive-therapy inadequate responders initially had a transient decrease in lumbar spine, total hip, and femoral neck BMD but caught up with the other two groups at the end of 2 years (see box, below right).
The women were enrolled as part of the European Forteo Study trial, which compared three different teriparatide treatment regimens in postmenopausal women with established osteoporosis.
All enrolled women (868) were treated with teriparatide (20 mcg/day), calcium (500 mg/day), and vitamin D (400–800 IU/day) supplements for 1 year.
At the end of the first year, the women were randomized at a ratio of 3:1:1 to 1 year of treatment with 20 mcg/day teriparatide, treatment with 60 mg/day raloxifene (Evista), or treatment with calcium and vitamin D supplements alone.
A fourth cohort of women who were determined to have had an inadequate response to prior antiresorptive therapy received 20 mcg/day teriparatide for 2 years.
This study was funded in part by Eli Lilly & Co., the manufacturer of teriparatide. Dr. Obermayer-Pietsch disclosed that she has received grants from Eli Lilly & Co.
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