my personal edition > menopause > news


  E-Mail this DGDispatch to a colleague

DGDispatch

Weekly Risedronate Gets Similar Bone Mineral Density Results to Daily Formulation: Presented at AACE

By Paula Moyer

SAN DIEGO, CA -- May 20, 2003 -- Postmenopausal women who take weekly risedronate (Actonel) get equivalent bone antiresorptive benefits as patients who use the daily dosing regimen.

"These results are encouraging because the once-weekly regimen is very popular and convenient," said Earl W. Sod, PhD, senior scientist in clinical development, musculoskeletal division, Procter & Gamble Pharmaceuticals, Mason, Ohio. The principal investigator in the study was Robert R. Recker, MD, an endocrinology fellow, Creighton University, Omaha, Neb.

"Because the daily and weekly dosing regimens produce similar results, physicians can comfortably offer the 35 mg once-weekly formulation as an alternative to 5 mg daily dosing," Dr. Sod said.

Drs. Sod and Recker presented the findings here on May 16^th at the American Association of Clinical Endocrinologists 12^th Annual Meeting and Clinical Congress. They designed their study to compare the efficacy of a daily dose of risedronate, consisting of 5 mg, with 2 weekly formulations -- one at 35 mg weekly, and the other at 50 mg weekly. The study population consisted of 109 women with postmenopausal osteoporosis.

The primary aim was to assess changes in bone mineral density (BMD) in the lumbar spine at 1 year, and to assess safety for the 2-year study period. The subjects were randomized to either the weekly or the daily dose.

Patients' lumbar spine BMD changes were equivalent in both of the weekly dose groups, and the daily group. "This finding," said Dr. Sod, "led the investigative team to conclude that both of the weekly doses were as efficacious as the daily dose of antiresorptive therapies."

"To assess safety, the investigators obtained iliac-crest biopsy specimens from all participants at baseline, and for 86 participants at year 2. Patients received regional anesthesia for the biopsy procedures," Dr. Sod said.

The investigators found no histological abnormalities in any of the treatment groups. The investigators concluded that this finding implied normal bone quality, even in patients who received the highest dose.

"There were double tetracycline-labeled surfaces in all end pointbiopsy specimens. Trabecular and cortical bone structural variables were generally unchanged, and similar among all groups. Among participants in the 3 dosing groups, the bone turnover was reduced by approximately 65%, a significant reduction," Dr. Sod said.

He and his colleagues found increased bone formation periods in all the treatment groups, and found significant increases in the daily group, and the 35 mg weekly group. These findings were confirmatory of previous data for 5 mg of risedronate daily, according to Dr. Sod. They found that the median mineralizing surface was approximately 1.5% in all groups after 2 years of therapy.

Median change in mineral apposition rate (MAR) was positive in all groups, and significantly so in the weekly-dosing groups. Although no groups had changes in bone wall thickness, the investigators inferred that risedronate had an anabolic effect, due to the increased MAR and bone formation periods.

This study was sponsored by Procter & Gamble Pharmaceuticals, Mason, Ohio.


[Study title: Bone Histology And Histomorphometry in a 2-Year Risedronate Study Comparing Daily and Weekly Dosing. Abstract 67]

E-Mail this DGDispatch to a colleague

To print, use this version