Shares of Pacific Biosciences of California (PACB) were up 5.1% to $5.34 in premarket trading on Tuesday. The Menlo Park, Calif. company is a manufacturer of sequencing systems.

AMAG Pharmaceuticals (AMAG) shares were down nearly 4% to $21.80. The Waltham, Mass.-based company on Tuesday announced unaudited consolidated financial results for the fourth quarter and full-year 2016. AMAG reported fourth-quarter GAAP revenue of $151.6 million, compared with $108.7 million in the year-ago period. Non-GAAP revenue was  $153 million, compared with $120.6 million a year ago. Adjusted Ebitda was $77.4 million, up 26% year-over-year. Also on Tuesday, AMAG and Endoceutics announced an exclusive license agreement for Intraros (prasterone).

Other biotech stock movers include Global Blood Therapeutics (GBT) , whose shares rose 2.4% to $21. The South San Francisco-based company's lead product candidate is GBT440, which is being developed as a therapy for sickle cell disease.