TRENTON, N.J. — U.S. spending on prescription drugs rose 8.5 percent last year, slightly less than in 2014, driven mainly by growing use of ultra-expensive new drugs and price hikes on other medicines. A report from data firm IMS Health estimates patients, insurers, government programs and other payers spent a combined $309.5 billion last year on prescription medicines. The…

Embattled Valeant Pharmaceuticals fell short of profit expectations in the fourth quarter and slashed its guidance for the current quarter and the full year, citing lower sales across many of its businesses. Shares slumped almost 19 percent in premarket trading ahead of the opening bell Tuesday. The Canadian drugmaker is facing a Securities and Exchange…