Gilead Sciences Falls Amid AbbVie Deal With Express Scripts

Shares of Gilead Sciences, Inc. GILD fell over 12 percent in early trading Monday amid news that AbbVie Inc ABBV will make its Hepatitis C treatment through Express Scripts Holding Company ESRX.

According to the press release, AbbVie’s Viekira Pak medication, approved by the U.S. Food and Drug Administration on December 19, was determined to be at least clinically equivalent to Harvoni® (ledipasvir and sofosbuvir) and Sovaldi® (sofosbuvir) by Express Scripts' independent Pharmacy & Therapeutics Committee. As a result of the committee's determination, Viekira Pak will immediately be added to the Express Scripts formulary, and will be the exclusive option for patients with genotype 1 hepatitis C, regardless of symptoms or disease progression, starting January 1, 2015.

Investors appeared to assumed that the AbbVie deal will take away market share from Gilead Sciences, which recently traded at $95.70, down 11.76 percent.

AbbVie Inc recently traded at $67.93, up 0.32 percent.