New Once A Year Osteoporosis Drug Shows Promise

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Main Category: Bones / Orthopaedics
Also Included In: Women's Health / Gynecology;  Seniors / Aging;  Clinical Trials / Drug Trials
Article Date: 03 May 2007 - 0:00 PDT

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Recently completed international phase III trials on Novartis Pharmaceuticals Corporation's new drug Reclast (zoledronic acid) suggest that a once yearly infusion over three years significantly reduces the risk of all types osteoporosis bone fractures in women with postmenopausal osteoporosis.

The findings are published in the The New England Journal of Medicine (NEJM) .

A Novartis statement said this finding:

"Marks the first time that an osteoporosis treatment significantly reduced all types of fractures in a single study."

Dr Dennis Black, lead scientist on the study and professor of epidemiology and biostatistics at the University of California, San Francisco, said:

"Unfortunately, many patients who are prescribed oral therapies stop treatment or take less than the full dose throughout a full year, which leads to reduced fracture protection."

"A once-yearly infusion is an exciting potential treatment option because it offers fracture protection for a full year with one dose," he explained.

Known as the Pivotal Fracture Trial, the phase III study examined the efficacy and safety of Reclast (zoledronic acid) in reducing bone fracture risk in women with postmenopausal osteoporosis. The participants were enrolled from 27 different countries.

The study was designed as a double-blind, placebo-controlled trial. This means neither the randomly assigned patients nor the health professionals who gave them the drugs knew whether they were on the active drug or the placebo.

3,889 patients aged 65 to 89 (mean age of 73 years) had a single 15-minute infusion of 5 mg of zoledronic acid and 3,876 had the placebo.

The patients were medicated at the start of the trial, 12 months and 24 months later. Then they were followed up for another 12 months.

The scientists measured new vertebral fractures in patients who were not on other osteoporosis medications at the same time, and hip fractures in all patients. They also measured mineral bone density, turnover markers and overall safety.

The study showed that the drug Zoledronic acid was associated with:

-- Reduction in fracture frequency among areas of the body typically affected by osteoporosis: hip, spine and wrist, for example.
-- 70 per cent reduction in spine fractures.
-- 41 per cent reduction in hip fractures.
-- Reduction in spine fractures was sustained over 3 years: 60 per cent in first year, 71 per cent in second year, 70 per cent in third year.
-- Nonvertebral fractures were reduced by 25 per cent.
-- Clinical fractures were reduced by 33 per cent.
-- Clinical verterbral fractures were reduced by 77 per cent.
-- Significant improvement in bone mineral density.
-- Significant improvement in bone metabolism markers.

There were some adverse events in both placebo and drug groups, including changes to kidney function.

However, the drug group showed a higher incidence of serious atrial fibrillation (abnormal heart rhythm) compared to the placebo group (50 versus 20 patients), but this was not statistically significant (probability factor less than 1 in 1000).

The researchers concluded that:

"A once-yearly infusion of zoledronic acid during a 3-year period significantly reduced the risk of vertebral, hip, and other fractures."

Zoledronic acid (Reclast) belongs to a class of drugs called bisphosphonates. Women on this class of drugs with postmenopausal osteoporosis normally have to take a daily, weekly or monthly dose. This trial shows that Reclast, which is currently under review by the US Food and Drug Administration (FDA), would be effective as a yearly dose.

In osteoporosis the bone mineral density (BMD) of the bone is reduced and so is the protein content. This disrupts the internal structure and and reduces the tensile strength of the bone thus increasing risk of fracture.

Osteoporosis is the most common metabolic bone disease and affects over 10 million people in the US where it is estimated that half of all women over 50 will suffer at least one broken bone in their lifetime.

"Once-Yearly Zoledronic Acid for Treatment of Postmenopausal Osteoporosis."
Black, Dennis M., Delmas, Pierre D., Eastell, Richard, Reid, Ian R., Boonen, Steven, Cauley, Jane A., Cosman, Felicia, Lakatos, Peter, Leung, Ping Chung, Man, Zulema, Mautalen, Carlos, Mesenbrink, Peter, Hu, Huilin, Caminis, John, Tong, Karen, Rosario-Jansen, Theresa, Krasnow, Joel, Hue, Trisha F., Sellmeyer, Deborah, Eriksen, Erik Fink, Cummings, Steven R., the HORIZON Pivotal Fracture Trial.
N Engl J Med 2007 356: 1809-1822.
Volume 356:1809-1822, May 3, 2007, Number 18

Click here for Abstract.

click here for International Osteoporosis Foundation.

Written by: Catharine Paddock
Writer: Medical News Today


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