A handle assembly (101) for a delivery device the sequential release of trigger wires from a prosthesis to release the prosthesis from the delivery device. The handle assembly (101) has two handles, one of which is a rotating handle (122). The rotating handle (122) has a first (230) and second (250) trigger wire release mechanisms which operate to sequentially release a first and second trigger wire, respectively, and a locking mechanism. The other handle has a locking mechanism that prevents that operation of the second trigger wire release mechanism until the first trigger wire has been released.
