February 2012 (Update) - Case dismissed. U.S. District Judge said Wyeth had sufficiently cautioned investors in a May 2007 press release.
January 27, 2009 - A Wyeth shareholder filed a lawsuit over the proposed acquisition of Wyeth by Pfizer. The plaintiff asked a federal judge to block the drugmaker’s sale, saying that it’s “unlawful and unenforceable”, the $68 billion offer is too low, and that Wyeth directors failed to get the best price in the sale announced Jan. 26, breaching their fiduciary duty. According to the complaint the offer is “unfair and grossly inadequate because, among other things, the intrinsic value of Wyeth’s common stock is materially in excess of the amount offered”.

The plaintiff asked the judge to halt the transaction until Madison-based Wyeth adopts “a procedure or process to obtain a merger agreement providing the best possible terms for shareholders.” Pfizer agreed to pay a $4.5 billion breakup fee if banks decide against lending the drugmaker enough to complete the acquisition. Pfizer Inc. shares have fallen 16 percent in the week since the company announced it would buy Wyeth, cutting the value of the cash and stock transaction by about $3.8 billion, or 5.6 percent, to $64.2 billion. The acquisition would give Pfizer the depression pill Effexor and pneumonia vaccine Prevnar to offset some of the $12 billion in sales it begins losing in 2011 when cholesterol pill Lipitor, which generates a quarter of the company’s revenue, faces generic competition. The world's largest pharmaceuticals maker Pfizer Inc announced last Monday that it would purchase Wyeth in a deal worth 68 billion dollars. Pfizer announced to acquire Wyeth (NYSE:WYE) for $33 in cash and 0.985 of a share of PFE stock. Pfizer will pay roughly $49.44, based on a $16.70 in trading before the market opened from Friday's close of $17.45.

Bloomberg subsequently reported that investment banks including Morgan Stanley and Bank of America Corp. may share about $207 million in fees for arranging Pfizer Inc.’s takeover of Wyeth Inc., a rare feast amid the leanest merger market in four years and Pfizer’s advisers -- Bank of America, Goldman Sachs, JPMorgan, Barclays Plc and Citigroup Inc. -- together may get $82 million in fees, not counting what they’ll earn arranging a $22.5 billion lending package.

The two companies currently employ more than 129,000 people worldwide and Fierce Pharma reported that the fallout from Pfizer-Wyeth deal begins, as Pfizer announced today that it plans to cut another 10 percent of its workforce, or 7,800 jobs. And Mlive.com agrees that the Pfizer-Wyeth merger to mean job cuts, manufacturing-plant closures. Sanford C. Bernstein analyst Timothy Anderson predicts Pfizer would cut 70 percent of Wyeth's current $10 billion spending on R&D and marketing/admin, so Fierce Pharma.