Pharmaceutical giant Merck (MRK 2.93%) reported promising results from a phase II drug trial for its new osteoporosis drug, odanacatib. Merck plans to submit applications for the drug to U.S. regulatory agencies in the first six months of 2013, and to Japanese authorities later that year.

In the latest findings, the company noted statistically significant rates of bone mineral density at the end of the 24-month trial, in which 243 post-menopausal women were given weekly doses of the new drug. All participants in the trial had been treated previously for periods of at least three years with Merck's Fosamax.

Odanacatib works differently than other osteoporosis treatments.

The new drug treats bone density loss by inhibiting cat-K, a protein-digesting enzyme within bone-resorbing cells, according to the company. The results of the study showed significant improvement in bone mineral density (BMD) scores in study participants, aged 60 years and older, who were given the new drug versus those given a placebo.

Results showed improvement in hip BMD scores of +1.73%, +1.83%, and +0.83% in three key areas for those given odanacatib, compared with bone loss scores of -0.94%, -1.35%, and -1.87% in the placebo group. Lumbar spine improvements of 2.28% were noted with drug therapy, versus a bone loss of -0.30% for those receiving the placebo. No statistically significant differences were found in the results for the distal forearm.

The company wound down its phase III fracture risk reduction study in July, after the trial's data monitoring committee noted favorable results after the first interim analysis. Merck plans to conduct further studies to assess specific safety issues revealed in that analysis.

A final report is expected to be published sometime next year, after all data analysis is concluded. The findings were presented on Oct. 13, at the 34thannual meting of the American Society for Bone and Mineral Research.