UCB and Amgen (AMGN -0.19%) announced today that they have halted trials for CDP7851/AMG785, or romosozumab, a fracture-healing drug. The news follows completion of the drug's phase 2 trials, but before phase 3 trials had commenced.

In a UCB statement, the company alludes to its most recent results and "general regulatory guidance" as the primary reasons for not pursuing additional testing. The company also states that safety concerns were not an issue and that its phase 2 trials won't affect continued testing on a similar drug to treat osteoporosis in post-menopausal women.

"Our sclerostin antibody project with Amgen is one of the most innovative pipeline programs in UCB's portfolio," UCB Chief Medical Officer Iris Loew-Friedrich said in a statement today. "We are very excited about the phase 3 program in PMO [post-menopausal osteoporosis] which is ongoing as planned and should provide first results at the end of 2015. Safety and other data collected so far indicate the potential for a change of treatment paradigms in postmenopausal osteoporosis."

UCB notes that the fracture-healing drug's phase 2 results will be presented at a future conference  and that the decision to not pursue phase 3 trials has no impact on the company's 2012 financials. Shares of Amgen fell 1.6% today .