Jefferies analyst Jeffrey Holford "strongly' advises investors use yesterday's selloff in shares of AbbVie as a buying opportunity. The FDA warning letter applies to a very limited population within the hepatitis C market, which means it will have a limited impact on AbbVie's HCV franchise, Holford tells investors in a research note. Competitor Gilead (GILD) has also seen excess events in the Child-Pugh B population, the analyst points out. He keeps a Buy rating on AbbVie with an $85 price target. The stock closed yesterday down $5.57 to $48.26. Its partner Enanta Pharmaceuticals (ENTA) dropped $16.35 to $23.90.

Cantor Fitzgerald lowered the firm's price target on Gilead to $75 from $78 and keeps a Neutral rating on the shares. The firm, which made slight adjustments to all of its large-cap biotechnology models ahead of Q1 earnings season for the group, lowered its target for Gilead given slower expected HIV growth. The "usual seasonal headwinds that typically make this one of the weaker quarters for the industry," the analyst added in the preview note.