Check out the companies making headlines before the bell:
Apple – Apple issued a rare sales warning after Wednesday's closing bell, with CEO Tim Cook pointing to slowing iPhone sales in China. Cook reportedly is set to address Apple employees today about the warning and take questions from workers.
Celgene – The drugmaker agreed to be acquired by Bristol-Myers Squibb in a cash-and-stock deal valued at $74 billion, or $102.43 per Celgene share. Celgene share had closed Wednesday at $66.64 per share.
Johnson & Johnson – Johnson & Johnson saw sales in India fall by 3 percent for the 12-month period ending in March 2018, according to a Securities and Exchange Commission (SEC) filing. J&J's results in India are being hurt by India's strict medical device pricing policies.
UBS – UBS is denying speculation that it might merge with another bank, with rumors having centered on Deutsche Bank. Chairman Axel Weber told a German newspaper that a merger makes little sense for UBS, with his comments coming a few days after Deutsche Bank officials also denied that the bank was considering a tie-up.
Teva Pharmaceutical, Amgen – Teva and Amgen settled a dispute of Teva's generic version of an Amgen kidney disease drug. Teva will pay Amgen an undisclosed amount, and agreed to stop selling its version until mid-2021.
Tribune Media – Tribune has pulled its TV stations from Spectrum, the cable operator owned by Charter Communications, after the two sides failed to reach a new carriage agreement. About six million Spectrum customers lost access to local TV stations and more than 14 million nationwide can no longer see WGN America.
Humana – Humana will reaffirm its 2018 full-year guidance of an adjusted $14.40 per share at meetings with investors, according to an SEC filing. That is slightly below Wall Street's consensus estimate for the health insurer of an adjusted $14.43 per share. Humana is scheduled to issue its fourth quarter and full year 2018 report on February 6.