US FDA calls for more trials on Genzyme's Lemtrada

There was a significant disappointment this morning for French drug major Sanofi (Euronext: SAN), when it revealed that its US biotech subsidiary Genzyme had received a Complete Response Letter from the US Food and Drug Administration for its supplemental Biologics License Application seeking approval of Lemtrada (alemtuzumab) for the treatment of relapsing forms of multiple sclerosis.

Sanofi’s shares came under pressure in early trading, falling 1% to 75.81 euros on the news.

The FDA has taken the position that Genzyme has not submitted evidence from adequate and well-controlled studies that demonstrate the benefits of Lemtrada outweigh its serious adverse effects. Genzyme understands that the conclusion is related to the design of the completed Phase III active comparator studies of Lemtrada in relapsing-remitting MS patients. FDA has also taken the position that one or more additional active comparator clinical trials of different design and execution are needed prior to the approval of Lemtrada.