Merck & Co. Inc. today said that it will not be seeking regulatory approval this year for a new heart-failure treatment that has not tested well in Phase 3 trials.

Merck, which is based in Whitehouse Station, N.J., and has operations in the Philadelphia region, says it will continue to analyze the data on rolofylline (MK-7418) with outside experts.

"Advances to help patients with acute heart failure, a disease that is the leading cause of hospitalization for patients over age 65 and that is associated with a high rate of mortality, have long been elusive," said Dan Bloomfield, executive director of cardiovascular research, Merck Research Laboratories.

He added that the results were "disappointing."