Check out which companies are making headlines before the bell:
AcelRx Pharmaceuticals - The company late Friday said it failed to win approval from the Food and Drug Administration for its pain treatment Zalviso.
Apple - The consumer technology company is close to acquiring the Pandora-for-talk-radio application Swell, re/code reported, citing multiple sources.
Dollar Tree - The discount retailer is buying rival Family Dollar Stores in a cash-and-stock deal valued at about $8.5 billion.
Pfizer - The drug manufacturer was downgraded to market perform from outperform by BMO Capital Markets.
Read MorePfizer's need for deal looms with earnings report
Zillow - The provider of online real estate listings agreed to acquire competitor Trulia for $3.5 billion.
—By CNBC's Kate Gibson.
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