On May 6, 2009, Genzyme Corporation issued a press release announcing that Genzyme is modifying its presentation of non-GAAP earnings per share in response to investor feedback. Genzyme will modify its presentation of GAAP to non-GAAP earnings to adjust only for stock compensation expenses and acquisition-related expenses, including in-process research and development (IPR&D). IPR&D associated with licensing deals, amortization, legal expenses, and one-time gains and losses will now be included in Genzyme's non-GAAP earnings per share. A copy of the press release is furnished as Exhibit 99.1 to this Form 8-K.

For comparison, Genzyme has revised its presentation of GAAP to non-GAAP reconciliations for 2002-2008 and these reconciliations can be found on the Investor Relations section of Genzyme's website at http://www.genzyme.com. Revised reconciliations for 2006 - 2008 and the first quarter of 2009 are furnished as Exhibit 99.2 to this Form 8-K.

The press release furnished herewith includes certain non-GAAP financial measures that involve adjustments to GAAP figures. Genzyme believes that these non-GAAP financial measures, when considered together with the GAAP figures, can enhance an overall understanding of Genzyme's past financial performance and its prospects for the future. The non-GAAP financial measures are included with the intent of providing both management and investors with a more complete understanding of underlying operational results and trends. In addition, these non-GAAP financial measures are among the primary indicators Genzyme management uses for planning and forecasting purposes and measuring the company's performance. These non-GAAP financial measures are not intended to be considered in isolation or as a substitute for GAAP figures.

The press release also reported that Genzyme outlined its plans for continued sustainable growth across each of its businesses, provided updates on anticipated near-term regulatory milestones and shared new clinical data at its Analyst Day Meeting on May 6, 2009.

Item 9.01     Financial Statements and Exhibits.

   (d)        Exhibits

  99.1        Press Release of Genzyme Corporation dated May 6, 2009.

  99.2        GAAP to non-GAAP reconciliations for 2006-2008 and the first quarter
              of 2009