( CAMBRIDGE Mass. June 18 2007 - Genz...)Genzyme Announces Results of Clinical Trials Investigating Powder,Form of Sevelamer Carbonate,Health

CAMBRIDGE, Mass., June 18, 2007 - Genzyme Corp. (Nasdaq: GENZ) today announced the results of two new studies comparing a powder form of Renvela™ (sevelamer carbonate) to Renagel® tablets (sevelamer hydrochloride), including one trial in which patients received the powder form three times per day, and one in which it was administered once per day.

Genzyme is developing Renvela in powder form to provide an additional option for patients with chronic kidney disease in managing their phosphate levels. A New Drug Application for Renvela tablets is already on file with the FDA, and previous studies have shown that the tablet formulation provides equivalent phosphate control to Renagel in patients on dialysis and significant phosphorus control in patients with chronic kidney disease who are not on dialysis. Today’s results are the first from trials comparing the efficacy of the powder form of Renvela to Renagel tablets.

In the first powder trial, patients treated with the powder form of Renvela three times per day experienced equivalent phosphorus control to patients treated with Renagel tablets three times per day. As a result, this trial successfully met its primary endpoint.

In the second trial, patients dosed with the powder form of Renvela once per day and those treated with Renagel tablets three times per day achieved statistically significant reductions in serum phosphorus, with both groups reaching target levels for phosphorus control outlined in the K/DOQI treatment guidelines. Phosphorus levels in the Renagel arm (4.6 mg/dL) were lower than those in the Renvela arm (5.3 mg/dL), and this trial did not achieve its primary endpoint of demonstrating non-inferiority of Renvela powder dosed once per day to Renagel tablets dosed three times per day.

In both trials, the safety profile of Renvela was consistent with the previous clinical experience of patients on dialysis
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