Amgen says osteoporosis drug successful in study

The three-year study involved 1,400 men undergoing androgen deprivation therapy, which is often used to slow the growth of prostate cancer. A possible side effect of the treatment is osteoporosis, or loss of bone density, making fractures more common.

During the study, men receiving the experimental drug experienced a significantly higher increase in lower back bone density. The drug also met its secondary goal, which was reducing the number of lower back fractures.

Adverse events, or side effects, associated with denosumab were generally similar to side effects seen from patients taking placebo. However, denosumab patients had a 6 percent rate of serious infections, compared with 5 percent of patients taking placebo, Amgen said.

Shares of Amgen rose 60 cents to $51.62 in morning trading.