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Genzyme MS drug gets mixed review

Genzyme, which has its headquarters in Kendall Square (above), is awaiting FDA action on its MS drug Lemtrada. A recent FDA report raised doubts about the drug’s future.John Tlumacki/Globe staff

A panel of medical specialists convened to advise US regulators concluded Wednesday that safety concerns about Genzyme’s much-anticipated multiple sclerosis drug don’t mean it can’t be approved for sale to patients who have tried other MS treatments.

But the Food and Drug Administration advisory committee also said the clinical trials of Genzyme’s drug, called Lemtrada, were flawed. That raised the question of whether the FDA will sign off on a medicine that — while eagerly awaited by many patients — underwent clinical studies deemed inadequate.

The advisory panel, in a daylong meeting in Silver Spring, Md., peppered representatives of Cambridge-based Genzyme and the FDA with questions about an FDA staff report that suggested Lemtrada may be too dangerous to approve because data linked it to side effects such as rashes and bleeding and a higher long-term risk of thyroid cancer.


In the end, the panel took a series of seemingly contradictory votes that generated as much confusion as guidance. The advisers, by an 11-to-6 vote, accepted the view of FDA staffers that there was “bias” in Genzyme’s clinical trials because the company didn’t keep patients from knowing whether they were taking Lemtrada or another drug.

“We indicated our discomfort with the clinical trial as designed,” Dr. Billy Dunn, acting deputy director of the FDA’s Division of Neurology Products, told the advisers.

But the committee, through a 12-to-6 vote, said Genzyme provided substantial evidence that Lemtrada worked for patients with relapsing MS, a potentially debilitating autoimmune disease that affects the brain and central nervous system of an estimated 400,000 people in the United States and 2.5 million worldwide.

By a 17-to-0 vote, the panel concluded that Lemtrada’s safety concerns shouldn’t preclude its approval for patients for whom other drugs aren’t effective. At the same time, it voted 16-to-0 that Genzyme’s drug should not be allowed for sale in the United States as a so-called first-line treatment for newly diagnosed MS patients. (Members of the panel abstained from some votes.)


While the panel pored over evidence from clinical trials, it also heard from MS patients, some of whom had taken Lemtrada in trials and testified it had been safe and effective. Panelists also heard from patient advocates, who noted other approved medicines also carry safety risks.

“If one of your family members had MS, wouldn’t you want them to have a choice?” said Melissa Burdick. “We, as patients, deserve the right to have a choice of therapy.”

While saying the data didn’t justify Lemtrada’s approval as a first-line therapy, panel member Dr. Robert R. Clancy, professor of neurology and pediatrics at the University of Pennsylvania School of Medicine, agreed patients should have the right to make decisions about the risks and benefits of Lemtrada in consultation with their doctors. “There are individuals who know what their own circumstances are (and) . . . are willing to roll the dice,” he said.

Unlike other MS treatments, Lemtrada is administered intravenously for five days the first year of use, and for three days the next year. After that, many patients no longer need treatments for years, according to Genzyme’s clinical studies. The drug, which played a pivotal role in Genzyme’s acquisition in 2011 by French drug maker Sanofi SA, was approved by European regulators in September for both new patients and those who have taken other drugs.


Shares of Sanofi dipped and rose by a fraction in after-hours trading on the New York Stock Exchange, reflecting investor confusion over Lemtrada’s fate. The drug had been expected to compete with treatments such as Tysabri, made by Weston-based Biogen Idec Inc., in an MS market estimated at as much as $13 billion annually.

FDA spokeswoman Tara Goodlin said the agency doesn’t disclose when it might take action on a drug application. But she stressed the FDA isn’t bound by advisory panel votes.

“The advisory committee provides advice to the FDA,” she said. “We take the committee’s advice into consideration when reviewing an application, but the ultimate decision lies with the FDA.”

Robert Weisman can be reached at robert.weisman@ globe.com. Follow him on Twitter @GlobeRobW.