(Bloomberg) -- Regeneron Pharmaceuticals Inc. said an extensive investigation into a rare and frightening side effect seen in clusters of patients getting its best-selling drug Eylea has been tied to syringes used to inject the medicine into the eye.
The company plans to stop distributing some Eylea kits that contain syringes made from batches that were linked to higher rates of the condition, known as intraocular inflammation.
Doctors shouldn’t use syringes that are included in some -- but not all -- Eylea packages, the drugmaker said in a separate statement on Wednesday. The investigation, which is still under way, didn’t find any specific flaw with the syringes, though their use was more common among patients who developed the side effect, the company said.
Regeneron will exchange affected kits that have already been sold to eye doctors as needed, spokeswoman Hala Mirza said. The syringes’ manufacturer, Becton, Dickinson & Co., didn’t immediately return a call seeking comments.
None of the affected syringes were shipped to doctors outside the U.S., Bayer, which licenses international marketing rights for Eylea, said in a statement on Thursday. Outside the U.S., syringes aren’t provided with the drug at all, the Leverkusen, Germany-based company said.
The side effect, which is marked by pain and a sharp decline in vision, is often temporary and can be treated with steroids. Regeneron said it didn’t find any association between the inflammation and Eylea itself.
The company, based in Tarrytown, New York, said it has told the U.S. Food and Drug Administration and the American Society of Retina Specialists about its findings and its plan to address the situation.
Regeneron shares gained 1 percent to 323.66 at 9:32 a.m. in New York.
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