Alexion sinks as PTAB institutes review that could shorten Soliris' exclusivity

Alexion shed nearly $2.6 billion in market cap Friday after an arm of the U.S. Patent and Trademark Office said it will review the validity of three patents covering Soliris based on an inter partes review challenge from Amgen. If the patents are invalidated, the anti-C5 mAb could lose its exclusivity in 2021, making it all the more urgent that the biotech continues to transition patients to Soliris' longer-acting successor, Ultomiris.

On Friday, the USPTO's Patent Trial and Appeal Board instituted the IPR proceedings, concluding that petitions from Amgen Inc. (NASDAQ:AMGN) "demonstrated a reasonable likelihood" that the petitioner can show the three Soliris eculizumab patents are invalid on the basis of obviousness. PTAB must decide within a year whether to uphold or invalidate the patents...