Revenue performance for the quarter reflected steady additions of new 
      patients with paroxysmal nocturnal hemoglobinuria (PNH) commencing 
      Soliris therapy in Alexion's core territories of the US, Western Europe 
      and Japan, as well as in new countries. Revenues were further augmented 
      by an increasing number of new patients with atypical hemolytic uremic 
      syndrome (aHUS) commencing Soliris treatment, as well as by $3.3 million 
      from shipments of Soliris that occurred in 2011.
    
    
      Soliris is approved for patients with PNH in the US (2007), European 
      Union (2007), Japan (2010) and other territories as the first and only 
      treatment indicated for this ultra-rare, debilitating and 
      life-threatening blood disease. Soliris is also approved as the first 
      and only treatment for patients with aHUS, an ultra-rare, 
      life-threatening, genetic disease, in the US (September 2011) and in the 
      European Union (November 2011).
    
    
      Alexion's non-GAAP operating results are equal to GAAP operating results 
      adjusted for the impact of share-based compensation, costs associated 
      with acquisitions, taxes that are not payable in cash (non-cash taxes) 
      attributable to the utilization of US net operating losses, and taxes 
      related to acquisition structuring. The following summary table is 
      provided for investors' convenience:
    
    
    
      Second Quarter 2012 Non-GAAP Financial Results:
    
    
      The Company reported non-GAAP net income of $94.1 million, or $0.47 per 
      share, in the second quarter of 2012, compared to non-GAAP net income of 
      $56.8 million, or $0.29 per share, in the second quarter of 2011.
    
    
      Alexion's non-GAAP operating expenses for Q2 2012 were $142.2 million, 
      compared to $102.6 million for Q2 2011. Non-GAAP research and 
      development (R&D) expenses for Q2 2012 were $56.3 million, compared to 
      $33.4 million for Q2 2011. Non-GAAP selling, general and administrative 
      (SG&A) expenses for Q2 2012 were $85.9 million, compared to $69.2 
      million for Q2 2011.
    
    
      Second Quarter 2012 GAAP Financial Results:
    
    
      Alexion reported GAAP net income of $36.3 million, or $0.18 per share, 
      in the second quarter of 2012, compared to GAAP net income of $34.7 
      million, or $0.18 per share, in the second quarter of 2011. Q2 2012 GAAP 
      net income included $21.8 million of tax expense related to the 
      structuring of the Enobia acquisition.
    
    
      On a GAAP basis, operating expenses for Q2 2012 were $159.4 million, 
      compared to $114.9 million for Q2 2011. GAAP R&D expenses for Q2 2012 
      were $59.6 million, compared to $35.6 million for Q2 2011. GAAP SG&A 
      expenses were $94.9 million for Q2 2012, compared to $78.2 million for 
      Q2 2011.
    
    
      Balance Sheet:
    
    
      As of June 30, 2012, the Company had $806 million in cash and cash 
      equivalents, compared to $359 million at March 31, 2012. The Company 
      raised net proceeds of $462 million from the sale of 5,000,000 shares, 
      announced on May 23, 2012, in connection with its inclusion in the S&P 
      500 Index. The Company also reduced total debt from $355 million at 
      March 31, 2012 to $228 million at June 30, 2012.
    
    
      "In the second quarter, we continued to provide Soliris to a substantial 
      number of new patients with PNH, both in our core territories and in new 
      countries, while also serving an increasing number of new patients with 
      aHUS," said Leonard Bell, M.D., Chief Executive Officer of Alexion. "We 
      also advanced our eight lead development programs which include five 
      highly innovative biologics. In the second half of 2012, the global 
      Alexion team will drive forward to serve more patients with PNH and aHUS 
      around the world, and to bring life-transforming innovation to patients 
      with additional severe and life-threatening ultra-rare disorders."
    
    
      Research and Development Programs:
    
    
      Alexion currently has lead development programs underway with five 
      highly innovative therapeutics, including eculizumab (Soliris), which 
      are being investigated across eight severe and ultra-rare disorders 
      beyond PNH and aHUS.
    
    
      Ultra-Rare Disease Programs With Eculizumab
    
    
      - 
        Nephrology: STEC-HUS and Acute Humoral Kidney Rejection (AHR): The 
        European Commission has granted orphan designation for eculizumab as a 
        treatment for patients with STEC-HUS, a severe, ultra-rare, and 
        life-threatening inflammatory disorder. Separately, enrollment 
        continues in a Company-sponsored, multi-national, living-donor kidney 
        transplant trial in patients at elevated risk of acute humoral 
        rejection, also known as antibody mediated rejection, and the Company 
        has initiated a deceased-donor kidney transplant study with enrollment 
        expected to begin later this year.
      
 
      - 
        Neurology: NMO and MG: Data from the investigator-initiated 
        Phase 2 clinical trial of eculizumab in severe and refractory 
        neuromyelitis optica (NMO) are expected to be presented at a 
        scientific meeting in the second half of 2012. Alexion is also 
        currently working with investigators to design the next clinical trial 
        to evaluate eculizumab as a treatment for patients with severe and 
        refractory myasthenia gravis (MG).
      
 
    
    
      Ultra-Rare Disease Programs With Highly Innovative 
      Therapeutic Candidates Beyond Eculizumab
    
    
      - 
        Asfotase Alfa: During Q2, Alexion initiated its planned natural 
        history study in infants with hypophosphatasia (HPP), an ultra-rare, 
        inherited, and life-threatening metabolic disease.
      
 
      - 
        cPMP Replacement Therapy: The Company is conducting pre-IND 
        toxicology studies with its cPMP replacement therapy for the treatment 
        of patients with the severe, ultra-rare, and genetic, fatal metabolic 
        disorder Molybdenum Cofactor Deficiency Type A.
      
 
      - 
        ALXN1102 (previously TT30): Enrollment continues in a Phase I 
        study to characterize the mechanism of action and develop initial 
        safety data for ALXN1102, a novel complement inhibitor.
      
 
      - 
        ALXN1007: Enrollment continues in a Phase I study of ALXN1007, 
        a novel anti-inflammatory antibody, to evaluate the safety, 
        tolerability, pharmacokinetics and pharmacodynamics of this compound 
        in healthy volunteers.
      
 
    
    
      2012 Financial Guidance:
    
    
      Alexion today announced that it is raising its 2012 revenue guidance 
      from the previous range of $1.065 to $1.085 billion now to the higher 
      range of $1.110 to $1.125 billion. The upward revision reflects 
      continued global growth of Soliris in PNH and growth from the ongoing 
      launch of Soliris in aHUS. 2012 guidance for non-GAAP SG&A is being 
      increased from the previous range of $345 to $355 million, now to $360 
      to $370 million, reflecting continued investment in the growth of the 
      Company's global operations. Non-GAAP R&D guidance remains unchanged. 
      Guidance for 2012 non-GAAP earnings per share is being raised, from the 
      previous range of $1.65 to $1.75 per share, now to the higher range of 
      $1.78 to $1.88 per share for the year. Shares outstanding are expected 
      to be approximately 203 million in the third quarter and approximately 
      204 million in the fourth quarter. All other items of the 2012 financial 
      guidance provided in the Company's press release of April 24, 2012 are 
      being reiterated at this time.