Forteo May Spur New Bone Growth in the Jaw
Studies show teriparatide, brand name Forteo, may help regrow jawbone loss due to periodontal disease or osteonecrosis.
Two studies suggest that the drug teriparatide, or Forteo, may help people who have lost bone in their jaws because of periodontal disease or osteonecrosis.
Periodontal disease is severe, chronic inflammation of the gums that is a major cause of tooth loss. It affects 1 in 5 American adults, and it is seen more frequently in people with rheumatoid arthritis, or RA, than in the general population.
Osteonecrosis is the death of bone tissue, and it can occur as a rare side effect related to the use of bisphosphonates, drugs used to treat cancer and osteoporosis.
Teriparatide is an injectable form of parathyroid hormone. It has been approved by the U.S. Food and Drug Administration for several years as a treatment for osteoporosis. Unlike medications that treat bone loss by stopping bone breakdown, however, teriparatide works by spurring the growth of new bone.
In the New England Journal of Medicine, researchers from Melbourne, Australia present a case study of an 88-year-old woman who developed osteonecrosis of the jaw after taking the corticosteroid medication prednisolone for 20 years and the bisphosphonate drug alendronate, or Fosamax, for 10 years.
She developed jaw wounds and suffered from pain for a year before agreeing to try teripartide. After eight weeks, her symptoms disappeared, and her osteonecrosis resolved.
Researchers say teriparatide appears to have healed the bone by stimulating new growth. But they stress this has been shown only in a few patients so they say a randomized, controlled trial is needed for further proof.
“Osteonecrosis of the jaw has been difficult to treat, but we hypothesize that teriparatide may be a novel effective treatment, which requires further study,” says Dr. Ada Cheung, an endocrinologist at The University of Melbourne in Australia.
“If teriparatide was proven in a randomized controlled trial to heal osteonecrosis of the jaw, this would be a significant advance as there are currently no good treatments for osteonecrosis of the jaw," Dr. Cheung says. "Patients can have painful symptoms for years and often require multiple surgical procedures to clean the infected bone as well as prolonged courses of antibiotics."
A second study reported in the same journal tested teriparatide for the first time in the treatment of bone loss in the mouth caused by periodontal disease.
Researchers at the University of Michigan studied 40 patients with periodontal disease. All were treated traditionally with periodontal surgery, but only half the group also received teriparatide injections for six weeks.
After one year, the group given teriparatide had a 29 percent improvement in their bone levels, compared to a 3 percent improvement among those who didn’t get the injections. The patients taking teriparatide also saw more improvement in depth of the pockets between their teeth and gums.
“This is a small study but the very promising results suggest that this type of therapy could be very beneficial for patients with periodontal gum disease,” explains the study’s principal investigator, Laurie K. McCauley, PhD, professor and chair of Periodontics and Oral Medicine at the University of Michigan in Ann Arbor.
McCauley stresses that her study did not evaluate the impact of teriparatide on osteonecrosis, but she says all of these reports taken together increase the likelihood there will be more research on this topic in the future.
“There have been a few case reports of teriparatide use in osteoporosis patients with osteonecrosis with promising outcomes," McCauley says. “Our study suggests that it would be valuable to perform more studies of the action of teriparatide in oral bone that could support therapeutic approaches for osteoporosis patients in need of regenerating bone in the oral cavity.”
In an accompanying editorial, Andrew Grey, MD, of the University of Auckland in New Zealand agrees these initial reports and studies are promising, but he stresses many questions still remain – everything from dosing to cost to long-term effects.
Mark Varvares, MD, director of the Saint Louis University Cancer Center in Missouri has questions, too. He says while teriparatide might work for patients with early stage osteonecrosis, he has trouble believing it would make much of a difference for patients with a severe case of the disorder.
“By the time we see patients, a good chunk of the bone is dead and the only way to treat it is remove it,” Dr. Varvares says. “The bone can’t be revived. It has to be removed once it gets to that stage. So I don’t know how you would incorporate this new drug in treating patients with that disorder.”