PHILADELPHIA — Combining once-a-year zoledronic acid and daily teriparatide significantly increased bone mass in key skeletal sites in postmenopausal women with osteoporosis, according to a study presented at the annual meeting of the American College of Rheumatology.
The trial included 412 postmenopausal women considered to be at high risk for fracture. They were diagnosed with osteoporosis on the strength of having a T score that was 2.5 standard deviations below peak bone mass, or having a slightly better T score but a history of at least one fracture. The women were randomized to one of three treatment groups: treatment with zoledronic acid alone (137), with both zoledronic acid and teriparatide (137), and with teriparatide alone (138). The zoledronic acid dosage was 5 mg intravenously once per year. Teriparatide was given daily in a subcutaneous dose of 20 mcg.
Use of the two drugs in combination increased bone mineral density (BMD) at the spine more than did teriparatide alone, and at the hip more than did zoledronic acid alone, according to study presenter Dr. Kenneth G. Saag, the Jane Knight Lowe Chair of Medicine in Rheumatology at the University of Alabama at Birmingham.
BMD at the spine increased 7.51%, 7.05%, and 4.37% in the combination arm, teriparatide arm, and zoledronic acid arm, respectively. Combination therapy significantly increased lumbar spine BMD at weeks 13 and 26 and total hip BMD at weeks 13, 26, and 52, compared with teriparatide alone.
The incidence of serious adverse events was 9.5%, 14.6%, and 10.9% in the combination, zoledronic acid, and teriparatide arms, respectively.
Disclosures: Dr. Saag disclosed financial relationships with Eli Lilly & Co., maker of teriparatide (Forteo), and Novartis, maker of zoledronic acid (Reclast).