Strontium ranelate phase 2 dose-ranging studies: PREVOS and STRATOS studies

Area of Science:

• Endocrinology
• Rheumatology
• Pharmacology

Background:

• Postmenopausal osteoporosis is a significant health concern, characterized by bone loss and increased fracture risk.
• Early intervention is crucial for preventing bone loss and managing osteoporosis in postmenopausal women.

Purpose of the Study:

• To determine the minimum effective dose of strontium ranelate (SR) for preventing bone loss in early postmenopausal women (PREVOS study).
• To establish the minimum effective dose of SR for treating postmenopausal vertebral osteoporosis (STRATOS study).

Main Methods:

• Two randomized, double-blind, placebo-controlled, dose-finding studies (PREVOS and STRATOS) were conducted over 2 years.
• Participants included nonosteoporotic postmenopausal women (PREVOS) and osteoporotic women with vertebral fractures (STRATOS).
• Lumbar bone mineral density (BMD) was the primary efficacy parameter, with secondary measures including vertebral deformities and bone metabolism markers.

Main Results:

• In PREVOS, 1 g/day SR significantly increased lumbar BMD compared to placebo (+5.53%).
• In STRATOS, 2 g/day SR significantly increased lumbar BMD (+7.3% per year) and reduced new vertebral deformities (RR 0.56).
• SR demonstrated favorable effects on bone formation and resorption markers and was well-tolerated in both studies.

Conclusions:

• The minimum effective dose of strontium ranelate for preventing bone loss in early postmenopausal women is 1 g/day.
• The minimum effective dose of strontium ranelate for treating postmenopausal osteoporosis is 2 g/day.
• Strontium ranelate is an effective and well-tolerated treatment option for postmenopausal bone loss and osteoporosis.