As Cambridge biotech Genzyme awaits an upcoming US regulatory decision on its experimental multiple sclerosis drug, the medicine has won approval for sale in Canada.
Genzyme said Friday that the regulatory agency Health Canada signed off on its Lemtrada therapy as a treatment for adults with relapsing remitting MS who didn't respond to drugs already on the market north of the border. More than 2.3 million people worldwide have been diagnosed with MS, a disease of the central nervous system, including about 100,000 in Canada.
Executives at Genzyme, owned by French drug maker Sanofi SA, are expecting a Food and Drug Administration ruling on Lemtrada by Dec. 27. The drug, which figured prominently in Sanofi’s negotiations to acquire Genzyme in 2011, was approved by European Union regulators in September, boosting to 30 the number of countries where patients have access to the therapy.
But its prospects for sale in the United States, the world’s largest market for prescription medicines, are far from certain after an FDA advisory committee meeting last month.
The panel of medical specialists convened to advise US regulators focused on safety concerns, such as rashes and bleeding and a higher long-term risk of thyroid cancer, but concluded Lemtrada could be approved for patients who have tried other MS treatments.
Still, the committee also said the clinical trials of Genzyme’s drug were flawed because the company didn’t keep patients from knowing whether they were taking Lemtrada or another medicine. That raised the question of whether the FDA will sign off on a therapy that — while eagerly awaited by many MS patients — underwent studies deemed inadequate.
FDA representatives declined to comment Friday on the status of their review. Genzyme executives weren’t available to discuss the Canadian approval, a spokeswoman said.
Patients who took Lemtrada during clinical trials and representatives of MS patient advocacy groups testified in favor of the drug during the advisory panel’s meeting in Silver Spring, Md., and have continued to press the FDA for a favorable ruling.
Former investors in Genzyme also have followed the FDA’s review of Lemtrada closely because, under terms of the agreement to be purchased by Sanofi, approval by the end of 2013 would trigger a milestone payment to holders of a special stock issued after the acquisition.