Effect of alendronate on HIV-associated osteoporosis: a randomized, double-blind, placebo-controlled, 96-week trial (ANRS 120).

Low bone mineral density (BMD) is common in HIV-infected patients. Bisphosphonates such as alendronate potently inhibit bone resorption and are effective against osteoporosis. The aim of the ANRS 120 Fosivir trial was to evaluate the effect of alendronate on low BMD in HIV-infected patients. HIV-1-infected adults with a t-score≤-2.5 at the lumbar spine and/or total hip, as assessed by dual x-ray absorptiometry, and no other known risk factors for low BMD, were randomized to receive either extended-release alendronate 70 mg weekly or placebo for 96 weeks, with stratification for gender. All the patients also received daily calcium carbonate (500 mg) and vitamin D (400 U). The primary endpoint for efficacy was the percentage change in BMD at the site with a t-score≤-2.5. Forty-four antiretroviral-treated patients (42 men, 2 women) were enrolled. The median age was 45 years, the median CD4 cell count was 422/mm(3), and viral load was <400 copies/ml in 84% of patients. Baseline characteristics were well balanced between the alendronate (n=20) and placebo (n=24) groups. At baseline, 15 patients (75%) in the alendronate group and 17 patients (71%) in the placebo group had a t-score≤-2.5 at the lumbar spine. In the main analysis, BMD at the site with a t-score≤-2.5 increased by 7.1% and 1.0%, respectively, in the alendronate (n=14) and placebo (n=20) groups at week 96 [mean difference, 6.1% (95% CI 2.8 to 9.3); p=0.0003]. Alendronate 70 mg weekly for 96 weeks improves BMD in HIV-1-infected patients on antiretroviral therapy.