* Deal to expand rare disease treatments * Avidity to separate early-stage cardiology programs into new company * Acquisition to help Novartis gain stronger foothold in US (Updates with more detail on Avidity, other Novartis deals, background) By Padmanabhan Ananthan and Angela Christy M Oct 26 (Reuters) – Swiss drugmaker Novartis on Sunday said it agreed to acquire U.S. biotech firm Avidity Biosciences for about $12 billion in cash, as the company looks to bolster its portfolio of treatments for rare muscle disorders. As per the terms of the deal, Avidity stockholders will receive $72 per share in cash, representing a premium of 46% to the company's closing on Friday. Bloomberg News reported on the deal earlier, citing a person familiar with the matter. Novartis has been proactively strik

See Full Page