AstraZeneca has completed its acquisition of the rights to Activis' branded respiratory business in the US and Canada.The company paid Activis initial consideration worth $600m as well as an extra $100m for a number of contractual consents and approvals.According to an investor note released on Tuesday, AstraZeneca has also agreed to pay low single-digit royalties above a certain revenue threshold.The acquisition has been made to expand AstraZeneca's global respiratory franchise and build on its acquisition of Almirall's 2014 portfolio by moving the company's development and commercialisation rights into the US for both Tudors Pressair and Duaklir Genuair.