The climb comes on the heels of two major recent acquisitions by Allergan in the biotech field. The Ireland-based company announced its $1.7 billion deal with Tobira Therapeutics on Tuesday, and made news last week after acquiring Vitae Pharmaceuticals in a $639 million all-cash deal. Other stocks rose amid speculation of more takeovers this week. Clovis Oncology finished up 2.7 percent and Eli Lilly also closed up about half a percent after rumors that Eli may buy the cancer treatment company.
Collegium Pharmaceutical was one of the largest gainers by percentage points Thursday, closing 19.3 percent higher after news that its chronic pain medication, Xtampza, will be more accessible to patients with United Healthcare insurance.
Sarepta continued to rise after it received approval from the FDA earlier this week for a muscular dystrophy drug. It closed up 8.5 percent for the day on Thursday and up more than twice its price from last week.
Mylan, one of the 10 most heavily weighted stocks in the ETF, traded more than 1.5 percent higher despite recent political pressure over the stark price increases of its life-saving EpiPen device.
-CNBC's Chris Hayes and Evelyn Cheng contributed to this report.