Avidity’s stock rockets on Bristol Myers deal that could mean $2.2 billion in milestone payments

Avidity Biosciences Inc. said Tuesday it’s expanding its cardiovascular collaboration with Bristol Myers Squibb Co. in a deal that will see Avidity receive $100 million upfront with the potential to earn up to $2.2 billion in milestone payments.

The news sent Avidity’s stock RNA up 30.5% in premarket trade.

Avidity will receive a $60 million…