What is the FDA warning for Aimovig?

Can you explain in detail what is the FDA warning for Aimovig? I understand it's a medication used to treat certain types of migraines, but I've heard there's a safety concern that the FDA has issued a warning about. Could you elaborate on the specific nature of this warning, the potential risks involved, and what patients should be aware of when considering using Aimovig? Additionally, is there any advice you can offer for patients who are currently using Aimovig or considering starting the treatment?