In preliminary studies, 93% of 145 patients who had unhealed bone fractures -- some for as long as six months -- had significant healing after only eight to 12 weeks on the drug, called teriparatide, or Forteo.
Others with such injuries are forced to go into nursing homes, so the drug has great promise for reducing medical costs and improving quality of life, said Dr. Susan V. Bukata of the University of Rochester Medical Center, lead author of the study.
"This is a drug with a good clinical track record that has proved to be remarkably safe, and it could have great utility," said Dr. Richard S. Bockman, chief of the endocrine service at the Hospital for Special Surgery in New York, who was not involved in the study.
Bukata and her colleagues reported their findings at a February meeting of the Orthopaedic Research Society and are now submitting a report to a major journal.
Teriparatide is a fragment of parathyroid hormone, containing 34 amino acids compared with the 84 in the intact hormone. Studies as early as the 1930s showed that parathyroid hormone injections increase bone density and healing in animals. But because the hormone could not be patented, pharmaceutical companies were loath to expend money on clinical trials.
In 2003, however, Eli Lilly & Co. received approval to market teriparatide under the brand name Forteo for treatment of severe osteoporosis. An estimated half-million people have been treated with the drug.
Many physicians have reported observing accelerated healing of fractures in the elderly given Forteo for osteoporosis, and some doctors are now using the drug off-label for such purposes, Bockman said.
Bukata and her colleagues studied 145 mostly elderly patients with fractures at a variety of sites. All the fractures had proved resistant to healing, some for more than six months. The researchers found that 135 of the patients given teriparatide had complete healing of their fractures after eight to 12 weeks. Six had only partial healing, "but they were much more comfortable and happy with the results," she said. Only four patients received no benefit.
No adverse effects were noted, Bukata said. Three of the patients stopped using it because they did not like giving themselves injections, but two had already healed when they stopped.
The Rochester team is beginning a placebo-controlled trial, sponsored by the National Institutes of Health, on people with pelvic fractures. Such fractures "are very painful, and people can't walk for two to three to four months," Bukata said. "We want to get them up and moving as quickly as we can."
The team has begun another study, also sponsored by NIH, in spinal fractures. So far, "we have seen a fairly rapid response there, in eight weeks or so," she said.
The chief drawback of the treatment is the cost, about $800 per month. But if the patient's stay in a nursing home could be reduced by a week, "that would pay for the drugs," Bukata said.
And perhaps, "with more uses for the drug, maybe it will encourage others to make the product and lower costs," Bockman said.
Bukata and her colleagues give paid speeches for Lilly. The company provided the drugs for the research but had no control over the study.