The ongoing corporate battle to hold down health plan increases should show some results next year. But prescription drugs continue to foil attempts to truly rein in health care costs.

That is the main finding in a new health plan cost trend survey from benefits and HR consulting firm The Segal Group. It's the 18th edition of the trend survey, and Segal made no bones about the concerns raised by the trending of drug prices.

"New specialty drugs coming onto the market and price increases for brand-name drugs are the main forces driving prescription drug plan cost trends," said Edward Kaplan, Segal's national health practice leader. "Typically, less than one percent of all prescriptions are specialty drug medications, yet these drugs now account for more than 25 percent of total prescription drug cost trends. The projected specialty drug/biotech trend rate for 2015 is an exceptionally high 19.4 percent."