Pfizer to Acquire Encysive Pharmaceuticals

  
    
  
  
    
      Pfizer Inc today announced that it has entered into an agreement to 
      acquire Encysive Pharmaceuticals Inc. (NASDAQ: ENCY), a publicly held 
      biopharmaceutical company whose product for the treatment of pulmonary 
      arterial hypertension (PAH) is commercially available in much of the 
      European Union and is approved in other markets.
    
    
      Under the terms of the agreement, Pfizer will make a cash tender offer 
      for all issued and outstanding shares of Encysive for $2.35 per share, 
      representing an equity value of approximately $195 million. Following 
      completion of the tender offer, a subsidiary of Pfizer will merge with 
      Encysive, with the outstanding Encysive shares not tendered pursuant to 
      the tender offer converted into the right to receive the per share price 
      paid under the offer. Upon Pfizer's acquisition of Encysive, Pfizer will 
      assume Encysive's change of control repurchase obligations under its 
      2.5% convertible senior notes. The Board of Directors of Encysive has 
      unanimously approved the merger agreement and unanimously recommends 
      that Encysive stockholders accept the tender offer and tender their 
      shares.
    
    
      Pfizer will acquire the rights to THELIN® 
      (sitaxsentan sodium), an oral, once-daily endothelin A receptor 
      antagonist (ETRA) for the treatment of PAH, as well as Encysive’s 
      other pipeline candidates. THELIN has been approved for marketing in the 
      European Union (EU), and is currently available in many EU states, 
      including the United Kingdom, Germany, Ireland, Spain, France, Italy, 
      Belgium, Luxembourg and the Netherlands. THELIN has also been approved 
      in Australia and Canada. In the United States, THELIN has been the 
      subject of three approvable letters from the U.S. Food and Drug 
      Administration (FDA). Pfizer plans to conduct a pivotal Phase III trial 
      to support registration in the U.S.
    
    
      “The process initiated in July of 2007 to 
      review Encysive’s strategic alternatives led 
      us to consider a range of opportunities for increasing shareholder value,” 
      commented George W. Cole, president and chief executive officer of 
      Encysive. “After a thorough analysis, Encysive’s 
      Board of Directors concluded that this cash transaction with Pfizer 
      represents the best option for our shareholders now. Pfizer has come 
      with a superior offer and with an in-depth understanding of pulmonary 
      arterial hypertension, our primary therapeutic focus. We look forward to 
      working with representatives of Pfizer in finalizing this transaction, 
      and in transitioning our U.S. and EU operations.”
    
    
      “The acquisition of Encysive will add growing, 
      near-term revenue from the European market and increase our already 
      strong presence in the cardio-respiratory arena with a product that 
      complements REVATIO™, a PAH treatment that 
      was discovered and developed by Pfizer researchers,” 
      said Ian Read, president of Pfizer’s 
      Worldwide Pharmaceutical Operations. “We look 
      forward to applying Pfizer’s significant 
      resources to the launch of THELIN in additional countries.”
    
    
      “Our commitment to pursue compelling science 
      taking place outside of our laboratories is ongoing, and the acquisition 
      of Encysive is an example of that effort,” 
      added Martin Mackay, Ph.D., president of Pfizer Global Research and 
      Development. “With this agreement, we will 
      gain an important marketed product in PAH and will have the opportunity 
      to complete the development of this new medicine to treat this 
      devastating disease.”
    
    
      PAH is a progressive, incurable disease that is estimated to affect 
      100,000 to 200,000 people in North America and Europe, including about 
      55,000 persons in the United States. It may be of unknown cause 
      (idiopathic) or secondary to other disorders such as connective tissue 
      disease. Though relatively rare, the disease affects men and women of 
      all races and ages, but is more common among women aged 20 through 40. 
      The disease may be misdiagnosed as asthma, anemia or chronic obstructive 
      pulmonary disease.
    
    
      PAH is characterized by high blood pressure and structural changes in 
      the walls of the pulmonary arteries, the blood vessels that connect the 
      right side of the heart to the lungs. In PAH, the pulmonary arteries 
      become thickened and constricted, forcing the heart to work harder to 
      pump blood through the lungs. Over time, the heart is unable to keep up, 
      and blood flow and oxygenation become inadequate to meet the body's 
      demands. This can lead to breathlessness, fatigue, dizziness, fainting, 
      edema, chest pain and the development of heart failure.
    
    
      THELIN works by blocking the action of endothelin-1, a potent mediator 
      of blood vessel constriction. THELIN acts to dilate the constricted 
      blood vessels, thereby reducing pulmonary arterial pressure and thus the 
      demands on the right side of the heart improving exercise tolerance.
    
    
      The transaction is expected to close in the second quarter of 2008, 
      subject to customary closing conditions, including approval under the 
      Hart-Scott-Rodino Antitrust Improvements Act of 1976 and the acquisition 
      by Pfizer of a majority of Encysive’s shares 
      in the tender offer. Lazard Frères and Co., 
      LLC, and Weil, Gotshal & Manges LLP advised Pfizer on this transaction. 
      Morgan Stanley and Covington & Burling LLP advised Encysive.
    
    
      More information on both companies, THELIN and PAH is available at www.pfizer.com 
      and www.Encysive.com.
    
    
      DISCLOSURE NOTICE: The information contained in this release 
      is as of February 20, 2008. Except to the extent required by law, 
      neither Pfizer nor Encysive assume any obligation to update any 
      forward-looking statements contained in this release as a result of new 
      information or future events or developments.
    
    
      This release contains forward-looking information about an agreement 
      by Pfizer to acquire Explorer Pharmaceuticals Inc. and about Encysive’s 
      products and drug candidates and the potential benefits of such products 
      and drug candidates. Such information involves substantial risks and 
      uncertainties including, among other things, the satisfaction of 
      conditions to closing the agreement; the uncertainties inherent in 
      commercial, research and development activities; decisions by regulatory 
      authorities regarding whether and when to approve any drug applications 
      for such drug candidates as well as their decisions regarding labeling 
      and other matters that could affect the availability or commercial 
      potential of such drug candidates; and competitive developments.
    
    
      A further list and description of risks and uncertainties can be 
      found in Pfizer’s and Encysive’s 
      Annual Reports on Form 10-K for the fiscal year ended December 31, 2006 
      and in its reports on Form 10-Q and Form 8-K.
    
    
      Important Additional Information: The tender offer described 
      herein has not commenced. The description contained herein is 
      neither an offer to purchase nor a solicitation of an offer to sell 
      shares of Encysive. At the time the tender offer is commenced, Explorer 
      Acquisition Corp. and Pfizer intend to file a Tender Offer Statement 
      on Schedule TO containing an offer to purchase, forms of letters of 
      transmittal and other documents relating to the tender offer and 
      Encysive intends to file a Solicitation/Recommendation Statement on 
      Schedule 14D-9 with respect to the tender offer. Pfizer and Encysive 
      intend to mail these documents to the stockholders of Encysive. These 
      documents will contain important information about the tender offer and 
      stockholders of Encysive are urged to read them carefully when they 
      become available. Stockholders of Encysive will be able to obtain a free 
      copy of these documents (when they become available) at www.pfizer.com 
      and www.encysive.com 
      and the website maintained by the Securities and Exchange Commission at http://www.sec.gov/.