Investors in Prima Biomed Ltd. (NASDAQ:PBMD) are taking profits after the stock jumped by more than 300% this week, following the release of positive data from its Phase II trial of CAN-003 as a treatment for ovarian cancer. Prima shares decreased more than 17% to $2.53 per share in pre-market trading on Friday.

Seadrill Ltd (NYSE:SDRL) shares are down 2.15% in pre-market trading to $13.63, as oil prices slipped on Friday as worries over the impact of war in the Middle East on crude supplies were outweighed by reports of profit-taking ahead of a long weekend.

eLong, Inc. (ADR) (NASDAQ:LONG) shares increased more than 34% to $27.90 per share in pre-market trading, after announced its investment in eLong through acquiring eLong shares from certain selling shareholders, including Expedia, together with several other investors. Ctrip acquired a 37.6% equity stake in eLong for a total purchase price of approximately $400 million.

Eagle Rock Energy Partners, L.P. (NASDAQ:EROC) shares soared over 12% to $2.76 in pre-market trading after the energy company announced that it has entered into an Agreement and Plan of Merger pursuant to which a subsidiary of Vanguard will merge into Eagle Rock for total consideration of $474 million in Vanguard common units and the assumption of Eagle Rock’s net debt of $140 million as of March 31, 2015.