PTH prevents first fractures in early osteoporosis.(Gynecology)

SAN ANTONIO -- Intact human recombinant parathyroid hormone prevented both recurrent and first fractures in a multinational, randomized, placebo-controlled study of postmenopausal women with osteoporosis, Mark P. Ettinger, M.D., said at the annual meeting of the American College of Rheumatology.

Previous studies have shown that the parathyroid hormone (PTH) analog teriperatide can prevent fractures in patients with advanced disease who already have had a fracture. The Treatment of Osteoporosis With PTH (TOP) study was the first to demonstrate the prevention of first fractures in patients with earlier disease, Dr. Ettinger said.

"This is extremely important, because the presence of any existing fracture greatly increases the risk of subsequent fractures," he said.

The TOP study included 2,532 women whose mean age was 64.4 years and whose mean spine, total hip, and femoral neck bone mineral density (BMD) T-scores were -3.0, -1.9, and -2.2, respectively.

The study population was very different from other osteoporosis treatment cohorts, in that the patients were younger, and only 19% already had fractures. In previous PTH phase II and teriperatide phase III trials, fracture prevalence ranged from 37% to 100%, he said.

Patients were randomized to 100 mcg subcutaneous PTH daily or placebo. All patients also took 700 mg calcium and 400 U vitamin D each day.

A total of 1,737 patients--72% and 65% of the placebo and PTH groups, respectively--completed the 18-month study.