HEALTH FEATURE ARCHIVE
Summary: The FDA has approved Forteo (teriparatide), a new drug for osteoporosis that stimulates new bone formation. Forteo is a fragment of human parathyroid hormone (PTH), the hormone that regulates calcium metabolism in bones. The drug is given by daily injection.
Comment: Like most useful medications, Forteo may have its possible downside. In animals, it promotes the development of osteosarcoma, a type of bone cancer. In humans, osteosarcoma has not been reported but it remains a concern with Forteo. (The daily injections are also a downside.)
Barbara K. Hecht,
Frederick Hecht, M.D.
Medical Editors, MedicineNet.com
FDA APPROVES TERIPARATIDE TO TREAT OSTEOPOROSIS
November 26, 2002 -- FDA has approved teriparatide for the treatment of osteoporosis in postmenopausal women who are at high risk for having a fracture. The drug is also approved to increase bone mass in men with primary or hypogonadal osteoporosis who are at high risk for fracture.
An estimated 10 million Americans - 80 percent of them women - suffer from osteoporosis, a progressive thinning of bones that may lead to an increased risk of spine, wrist, and hip fractures.
Teriparatide is the first approved agent for the treatment of osteoporosis that stimulates new bone formation. Teriparatide is administered by injection once a day in the thigh or abdomen. The recommended dose is 20 mcg per day.
Teriparatide is a portion of human parathyroid hormone (PTH), which is the primary regulator of calcium and phosphate metabolism in bones. Daily injections of teriparatide stimulate new bone formation leading to increased bone mineral density.
Drugs approved to treat osteoporosis must be shown to preserve or increase bone density and maintain bone quality. The effects of teriparatide on bone mineral density and fractures were studied in 1,637 postmenopausal women with osteoporosis who were treated for a median time of 19-months and 437 men with primary or hypogonadal osteoporosis who were treated for ten months. Patients treated with 20 mcg of teriparatide per day, along with calcium and vitamin D supplementation, had statistically significant increases in bone mineral density (BMD) at the spine and hip when compared to patients taking only calcium and vitamin D supplementation. Clinical trials also demonstrated that teriparatide reduced the risk of vertebral and non-vertebral fractures in postmenopausal women. The effects of teriparatide on fracture risk have not been studied in men.
In animal studies with teriparatide, there was an increase in the number of rats developing osteosarcoma, a rare but serious cancer of the bone. In the human studies, no osteosarcomas were reported, but the possibility that humans treated with teriparatide may face an increased risk of developing this cancer cannot be ruled out. This safety issue is highlighted in a black box warning in the drug's label for health professionals and explained in a brochure, called a Medication Guide, for patients. To help ensure that patients are aware of important information about teriparatide, the Medication Guide will be distributed by the pharmacist each time the drug is dispensed. Because people with growing bones (i.e., children and adolescents) and people with Paget's disease of the bone have a higher risk for developing osteosarcoma, it is important that they not be treated with teriparatide.
Most side effects reported in association with teriparatide in clinical trials were mild and included nausea, dizziness, and leg cramps. During the clinical trials, early discontinuation due to adverse events occurred in 5.6% of patients assigned to placebo and 7.1% of patients taking teriparatide.
Persons with hypercalcemia, women who are pregnant or nursing, or persons who have ever been diagnosed with bone cancer or other cancers that have spread to the bones, should not use teriparatide. Because the effects of long-term treatment with teriparatide are not known at this time, therapy for more than 2 years is not recommended.
Teriparatide is manufactured by Eli Lilly and Company of Indianapolis, Ind., and will be marketed under the trade name Forteo.
Source: FDA Talk Paper # T02-49, November 26, 2002