Genzyme shares climbed yesterday after the US biotech reported forecast-topping quarterly revenues of $793 million, up 19%, on the back of strong sales of its enzyme replacement products.

Net income for the second quarter increased to $135 million from $124 million a year earlier, and Genzyme reiterated earlier guidance that it expects full-year revenues of $3.1-$3.3 billion.

Sales of Renagal (sevelamer HCl) for end-stage renal disease patients rose 26% to $127 million, while Fabry disease drug Fabrazyme (agalsidase beta) advanced 20% to $89 million, with the gains coming alongside an 8% hike in sales of Gaucher disease treatment Cerezyme (imiglucerase) to $254 million.

Cerezyme has been slowing down of late, but the second quarter increase marks an acceleration on the 6% hike in sales reported for the first quarter of 2006.

Meanwhile, Genzyme’s newly-launch drug Myozyme (alglucosidase alfa) for Pompe disease brought in $6.5 million in its first reported quarter. It was introduced in the USA in mid-May and is also rolling out in Europe.

Shares in the company closed up more than 8% to $62.74 yesterday.