A new study published in the New England Joural of Medicine has shown that in a direct comparison test with Fosamax, osteoporosis drug Forteo more than doubled osteoporosis patients’ bone density measurements and appreciably reduced the risk of new spinal fractures.

The study reviewed changes in bone density over an 18-month period, and found that Forteo improved lumbar spine density measurements by 7.2% compared with 3.4% for Fosamax, and increased hip density measurements by 3.8% versus 2.4% for Fosamax.

“Patients and their doctors need more bone-building options,” said Kenneth Saag, M.D., M.Sc., a professor in the UAB Division of Clinical Immunology and Rheumatology and the study’s lead author. “Because having arthritis and being on medication for that disease is important. Reducing your risk of hip fracture or spinal compression is equally important,” Saag said. “This study significantly improves our understanding of treatment options for secondary osteoporosis, which is osteoporosis caused by taking glucocorticoid drugs like prednisone,” he said.

Glucocortids are popular with arthritis patients to help reduce inflammation and shrink swollen tissues and joints, although these drugs can increase the risk of bone loss, bone fracture and osteoporosis. For patients diagnosed with or at risk for glucocorticoid-induced osteoporosis, a class of drugs called bisphosphonates—which includes Fosamax—is recommended by international guidelines. Meanwhile, Saag said expert opinion hoped that in the future Forteo would feature as an aid to building back bone, reducingm bone loss and minimizing fracture risks in arthritis patients.

The study authors took bone density measurements, and established that when compared to the Fosamax group the Forteo patients had higher levels of protein and biological markers of bone formation in their urine. In terms of serious side effects the differences between Forteo and Fosamax were not significant, said Dr. Saag. He and the study’s co-authors reached the conclusion that because parathyroid hormone appears to trigger the growth of bone-forming cells called osteoblasts, Forteo may effectively counteract the negative effects of glucocorticoid use in bones. Fosamax works to counteract osteoporosis through a different cell pathway.

Currently Forteo is only approved for use in postmenopausal women with osteoporosis, and in certain cases for men with hormonal-linked osteoporosis. The drug maker Eli Lilly and Company is awaiting federal approval to have Forteo listed among approved medicines in patients with glucocorticoid-induced osteoporosis.

These findings were published in the November 15, 2007 issue of the New England Journal of Medicine.