A multiple-sclerosis drug that was at the center of Sanofi SA's SAN.FR +1.12% $20 billion takeover battle for Genzyme Corp. three years ago was approved for sale in Europe on Tuesday, the drug's first regulatory approval world-wide.
The U.S. Food and Drug Administration is expected to decide later this year whether to approve the drug, Paris-based Sanofi said.
The drug, Lemtrada, was developed by Genzyme, the Cambridge, Mass., biotechnology company that is now a unit of Sanofi. When Sanofi first bid for Genzyme in 2010, the biotech company balked, arguing that Sanofi was undervaluing the company and its assets, including Lemtrada, which was still in development at the time.
Sanofi clinched the deal when it agreed to pay $20 billion plus a contingent value right—a pledge of an additional payment of as much as $3.8 billion should Genzyme meet certain sales and manufacturing targets, including gaining regulatory approval of Lemtrada.
In Paris, Sanofi shares rose 1.7% to ?3.30 ($97.73) Tuesday, after the company said it won marketing approval for the drug from the European Commission, the executive body of the European Union.
Lemtrada is the latest of several new drugs to hit the multiple-sclerosis market. The treatment is administered through five infusions over a five-day period, and then again one year later over three days. It is unclear whether patients will need additional infusions after that. Continuing clinical trials should answer that question, Mike Panzara, Genzyme's group vice president for multiple sclerosis and immune diseases, said Tuesday.
Sanofi declined to disclose what it plans to charge for Lemtrada, saying it will do so after it concludes negotiations with European health systems.
The company's other multiple-sclerosis drug, Aubagio, was approved in Europe last month. Bill Sibold, head of Genzyme's multiple-sclerosis franchise, said he expected Lemtrada to go on the market in Germany in the first half of October.
Mr. Sibold said that having two new drugs to sell would help the company break into an already crowded field that has been dominated by companies like Biogen Idec Inc. BIIB +0.06% and Teva Pharmaceutical Industries Ltd. TEVA +0.77% Genzyme, he added, hopes to develop other multiple-sclerosis treatments in the future.
"We're well-positioned to be here for the long-haul," Mr. Sibold said. "We have additional internal programs we're looking at, and we're constantly looking externally as well for new technologies."
Lemtrada is also known by the generic name alemtuzumab. The same compound was initially developed and marketed under a different brand name, Campath, as a leukemia treatment.
In multiple sclerosis, the body's immune system attacks the myelin sheath surrounding nerve cells, causing symptoms such as fatigue, vision loss, pain and problems with balance and coordination. Lemtrada attempts to combat this by binding to the surface of certain T-cells in the immune system and destroying them.
In one large clinical trial in 600 previously untreated patients, participants were given either Lemtrada or a standard treatment called Rebif and assessed over a two-year period. The trial showed that Lemtrada reduced the risk of relapses, with 22% of patients taking Lemtrada suffering a relapse versus 40% in the Rebif group.
Adverse events in the Lemtrada group included herpes infections and thyroid troubles that were mostly mild or moderate in severity. Three patients taking Lemtrada developed a rare bleeding disorder called immune thrombocytopenia.
The FDA recently extended its review of Lemtrada by three months but didn't ask Sanofi for more clinical data on the drug, Sanofi officials said Tuesday.
—Joseph Walker contributed to this article.
