Merck & Co is closing a Phase III trial assessing its osteoporosis drug odanacatib ahead of schedule after the drug hit all of its efficacy targets.

The US pharma major said that after an interim analysis of data from the study, an independent Data Monitoring Committee (DMC) recommended that it should be closed early "due to robust efficacy and a favorable benefit-risk profile".

Odanacatib is a novel drug that works by inhibiting cathepsin K, an enzyme found within osteoclast cells that breaks down bone tissue.

The Phase III randomised, placebo-controlled trial involved more than 16,000 patients and was designed to gage the safety and efficacy of the medicine in lowering the fracture risk of post-menopausal women with osteoporosis. 

Despite considering the benefit-risk profile to be positive, the DMC did note that safety issues remain "in certain selected areas", and therefore made recommendations to follow up on them. 

But Merck said that its original plan to carry out a blinded extension trial will enable further monitoring of safety issues anyway, in addition to providing extra efficacy data.

On the back of its positive performance in the multicentre trial, which Merck said will take "a number of months" to wind down, the company intends to file for approval of odanacatib in the US, Europe and Japan sometime in the second half of next year.

Investors welcomed news of the drug's ability to cut the risk of fractures in this subset of patients with osteoporosis as well as its step towards the market, pushing Merck's share price up 3%.