Japan’s Astellas Pharma Inc. is continuing its investment in gene therapies, following up its $3 billion acquisition of Audentes Therapeutics Inc. with a technology licensing deal with Dyno Therapeutics Inc. potentially worth more than $1.6 billion. Central to the deal is Cambridge, Mass.-based Dyno’s adeno-associated virus (AAV) vector technology, which can be used to direct gene therapies to skeletal and cardiac muscle.