COLORADO SPRINGS — The anabolic bone-forming agent teriparatide (Forteo) is winning anecdotal raves for augmentation of fracture healing in both nonosteoporotic and osteoporotic patients.
“This is a very exciting metabolic therapy. My experience so far really does show that it works,” Thomas P. Knecht, M.D., declared at a meeting of the Colorado chapter of the American College of Physicians.
Acceleration of fracture healing is an off-label use of teriparatide, the N-terminal 34-amino-acid chain of human parathyroid hormone. Teriparatide's approved indications are for treatment of postmenopausal osteoporotic women at high fracture risk, and for increasing bone mass in osteoporotic men at elevated fracture risk.
The evidence for augmentation of fracture healing comes from multiple favorable animal studies as well as anecdotal clinical experiences that are consistent with the animal findings, explained Dr. Knecht, an endocrinologist at the University of Utah, Salt Lake City.
He offered two illustrative cases from his own practice, both involving middle-aged recreational athletes eager for a rapid return to sports.
One was a 48-year-old man with type 1 diabetes and normal bone mineral density test scores who became severely hypoglycemic, lost consciousness, and fell, fracturing his right tibia and fibula in multiple places. Surgeons placed a metal rod knee to ankle. The bone pain quickly became nonlimiting after Dr. Knecht placed him on teriparatide. He began long-distance running 3 months post surgery, and downhill skiing a week after that.
“My assessment of this patient's response was that placebo can't do that. Nobody placebos their way through a fracture like that one. So you have to say the healing was dramatic and the pain response was dramatic,” he observed.
Another patient was a 38-year-old woman, also with normal T-scores on dual-energy x-ray absorptiometry bone mineral density testing, who fell while training for a half-marathon and fractured her great toe. The break involved the metatarsophalangeal joint. “That's a bad fracture for a runner,” the physician noted.
Yet her fracture pain resolved after a single week on teriparatide. Six weeks later she completed her half-marathon.
While both these patients had good bone mineral density, Dr. Knecht said he has regularly seen the same sort of results—“not only a dramatic pain response, but an absolutely striking metabolic response”—in patients he has placed on teriparatide to augment healing of osteoporotic fractures.
While daily subcutaneous injections of teriparatide are typically given for 2 years in patients taking the agent for the approved indications, 6 months of therapy appears to be “more than adequate” for fracture healing per se because the healing occurs so quickly, he continued.
This is a high-cost drug. Its off-label use to accelerate fracture healing requires a highly motivated patient willing to take on a substantial out-of-pocket expense. The one situation where Dr. Knecht has consistently found third-party payers willing to cover teriparatide for augmentation of fracture healing is in transplant patients.
“I treat a lot of transplant patients. Fracture is actually a big cause of death in transplant patients, so we can pretty much get anything we need covered for those people,” according to Dr. Knecht, who is on the speakers' bureau for Eli Lilly & Co., which markets teriparatide.
Teriparatide is the only anabolic or bone-building agent on the market. It targets osteoblasts. In contrast, antiresorptive agents slow the rate of bone mineral loss by mediating osteoclast activity.