MS Drug Lemtrada Rejected by FDA

A potential medication for treating multiple sclerosis (MS) has failed to gain U.S. approval, according to the U.S. Food and Drug Administration (FDA).

Clinical trials that involved Sanofi's latest drugs did not show that the benefits of the product outweighed "serious adverse effects."

Before the company sought the approval of Lemtrada, the FDA had asked Sanofi to conduct more clinical trials with different designs and methods featuring the drug. However, the Wall Street Journal notes that the company did not agree with the FDA's suggestions, which did not come as a surprise to the health organization-which prompted safety concerns when the drug was first reviewed in November.

"We are extremely disappointed with the outcome of the review and the implications for patients in the U.S. suffering with multiple sclerosis who remain in need of alternative therapies to manage a devastating disease," said Genzyme President and Chief Executive David Meeker, via the news organization.

Lemtrada must be received intravenously as an annual treatment, and is taken in one dose over five days and then another a year later, over a three day period.

However, based on Sanofi's existing MS treatments, side-effects ranging from liver problems to birth defects caused concerns for the new product. This was especially true for the existing MS treatment Aubagio.

The National Multiple Sclerosis Society notes that this disease is a chronic health issue that attacks the central nervous system, and can include mild symptoms ranging from numbness of the limbs to more severe issues such as paralysis or vision loss. However, as the disease may flare periodically and at unpredictable intervals, it can also disappear at certain times and remain in remission.

It's estimated that worldwide, 2.5 million individuals are affected by MS.