Alexion Skids as Muscle Drug Trial Fails to Meet Primary Goal

  • Shares fall the most since 2010 as results disappoint
  • Drug for muscle disease didn’t lead to activity improvements

Alexion Pharmaceuticals Inc. fell the most in six years after the company’s drug for a rare neuromuscular disease failed to meet its primary goal in a final-stage trial.

Alexion is studying the treatment, Soliris, in patients with an unmanageable form of the muscle-weakening illness myasthenia gravis. In a phase 3 clinical study, patients taking the drug didn’t report statistically significant changes in the daily activities they could perform after 26 weeks of treatment when compared with those on a placebo, Alexion said late Monday in a statement.

The shares fell 11 percent to $137.55 at 10:04 a.m. Tuesday in New York, after earlier declining to $137.01, the company’s biggest drop since May 2010.

Chief Executive Officer David Hallal said that there were positive signs in the study, including the fact that patients improved on some secondary measures of the trial.

“We are aware of a reasonable number of therapies for rare diseases with unmet needs where the FDA has granted approval without meeting conventional requirements like the primary endpoint,” Hallal said on a call with investors.

Main Drug

Soliris, which has been approved in the U.S. to treat two other diseases, generated $2.59 billion in sales for Alexion last year -- nearly all of the company’s revenue -- according to data compiled by Bloomberg.

Patients taking the drug did show some improvement in some secondary measurements in the trial, including doctors’ assessments of how severe their disease was, according to the statement. Alexion plans to present full results from the study on July 7 at the International Congress on Neuromuscular Diseases in Toronto.

Myasthenia gravis is a rare disease whose various forms affect about 20 out of every 100,000 people in the U.S., according to the Myasthenia Gravis Foundation of America. It’s not believed to be an inherited disease, according to the foundation. Alexion’s drug is meant to treat refractory generalized myasthenia gravis, a rare, untreatable subset of the disorder that affects about 10 to 15 percent of those affected, according to the company.

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