The past several months have seen many successful merger and acquisition announcements come and go, but for some companies, this has hardly been a summer of love. Several of Big Pharma’s big offers have been rejected, and some of these stories are still playing out. Only time will tell what the future holds for these proposed deals and sometimes troubled partnerships.

BMS & ImClone. In New York, ImClone Systems rejected an unsolicited $4.5-billion takeover bid from Bristol-Myers Squibb, calling it “inadequate.” The BMS offer was for $60 per share in cash, and ImClone said on Sept. 10 that it was approached by another company offering $70 per share. BMS currently holds a 17% stake in ImClone, and the companies worked together to develop and commercialize the cancer drug “Erbitux” (cetuximab). The heads of both companies have publicly exchanged letters disapproving of the other’s handling of the offer and disagreeing on the future of their collaborative product candidate IMC-11F8. ImClone did, however, say the company would consider another BMS offer. On Sept. 16, Jean-Marc Huet, chief financial officer for BMS, said the company was prepared to walk away from a deal with ImClone, according to an AP report.

King & Alpharma. Alpharma (Bridgewater, NJ) rejected a $33-per-share takeover bid from King Pharmaceuticals (Bristol, TN) on August 22, 2008, a deal worth $1.4 billion. On Sept. 12, King commenced a tender offer to acquire all of the outstanding shares of Class A common stock of Alpharma for $37 per share in cash, or $1.6 billion. The tender offer is scheduled to expire Oct. 10, 2008. Meanwhile, Alpharma’s board of directors urged shareholders to take no action until it evaluates the offer and makes a recommendation to shareholders, which it plans to do within 10 business days following the commencement of the tender offer. Alpharma said its board is exploring alternatives to maximize shareholder value, including a possible sale of the company to King or to another company.

Roche & Genentech. In late July, Roche made an unsolicited bid for the 44% of Genentech (South San Francisco, CA) that it does not already own. The offer was for $43.7 billion, or $89 per share. On Aug. 13, Genentech announced its special committee of the board of directors unanimously concluded that Roche’s offer of $89 per share “substantially undervalues the company” and the board rejected the offer. Genentech’s special committee says it would consider another proposal. Industry analysts predict Roche may up the offer to $53 billion, Reuters found in a recent poll.

Sanofi-Aventis Europe & Zentiva. On Sept. 3, 2008, Zentiva (Prague) advised shareholders to reject Sanofi-Aventis Europe’s (Paris) July 2008 unsolicited takeover offer. Sanofi is Zentiva’s largest shareholder and owns a 24.9% stake in the company. Zentiva’s board of directors said the offer of CZK 1050 per share ($63 per share), or 40 billion crowns ($2.39 billion) undervalues the company. Jiri Michal, chairman of the board and CEO of Zentiva, said “the Board believes that this offer falls a long way short of reflecting Zentiva’s fundamental value.” On Sept. 18, 2008, Sanofi extended the offer an additional 10-week period until Nov. 28, 2008.

Sun & Taro. In May 2008, Taro Pharmaceutical Industries (Haifa Bay, Israel) announced plans to terminate the merger agreement made with Sun Pharmaceutical Industries (Mumbai, India) in May 2007. This past August, Sun announced its victory over the litigation brought against it by Taro in the Tel-Aviv District Court, which rejected Taro’s idea that Sun violated Israeli law by not conducting a “special tender offer.” The Supreme Court of the State of Israel prohibited Sun from completing its existing tender offer to Taro shareholders until it hears arguments surrounding Taro’s appeal of the lower court’s decision. On Sept. 3, Sun extended the expiration date of its tender offer to Oct. 3, 2008. According to a Sept. 10 letter to shareholders, Taro Chairman Barrie Levitt says Sun’s unsolicited tender offer is on hold until December 8, 2008, when the appeal will be heard in the Supreme Court. Taro has urged shareholders not to accept the tender offer since July 2008 when Taro’s board of directors said it was “financially inadequate and is a ’sham’ offer.”