Postmenopausal women with severe osteoporosis, a condition that makes bones porous and more likely to break, Forteo (teriparatide), the first in a new class of drugs that stimulate new bone growth, is not as cost-effective as Fosamax (alendronate), a drug that halts bone loss and boosts bone density.

“While teriparatide is a promising new drug for the treatment of osteoporosis,” Dr. Hau Liu told Reuters Health, “primarily because of its high price, it is not cost-effective compared to alendronate, a less expensive, commonly used therapy.”

Teriparatide costs about $6,700 per year - roughly eight times more than alendronate, which costs about $900 per year. “If the price of teriparatide were reduced to about $3000 per year, it would become cost-effective,” Liu estimates.

Based on these findings, the authors suggest that for now teriparatide should be reserved for only the highest-risk women and for those who can’t tolerate standard treatments.

Liu and colleagues from Stanford University, California evaluated the cost-effectiveness of four strategies for the initial treatment of high-risk osteoporotic women: “usual care” (vitamin D and calcium); alendronate for 5 years; teriparatide for 2 years; and teriparatide for 2 years followed by alendronate for 5 years.

They report in the Archives of Internal Medicine that the alendronate-alone strategy (compared with usual care) costs $11,600 per quality-adjusted life-year gained, which “compares favorably to interventions accepted as cost-effective.”

Teriparatide-alone costs $172,300 per quality-adjusted life-year gained (compared with usual care) and is “not a rational choice,” according to the team, “because it is more expensive and produces a smaller increase in quality-adjusted life-years compared with alendronate alone.”

The sequential strategy of teriparatide followed by alendronate costs $156,500 per quality-adjusted life-year compared with treatment with alendronate alone, which is also not cost-effective.

“We were somewhat surprised that the sequential teriparatide/alendronate strategy was not cost-effective given the substantial anti-fracture benefit we ascribed to it,” Liu told Reuters Health. “Once again, we believe this lack of cost-effectiveness was primarily due to the high price of teriparatide,” the researcher added.

Sequential teriparatide/alendronate could become cost-effective with significant price reductions in teriparatide, if it was restricted to women at exceptionally high risk for fracture, or if short courses of teriparatide were as effective as longer courses of the medication, Liu and colleagues point out.

This study was funded by the Agency for Healthcare Research and Quality and by the Department of Veterans Affairs.

SOURCE: Archives of Internal Medicine, June 12, 2006.