A therapeutic system and a method that uses stents, and/or other implantable devices (104) for local delivery of a therapeutic agent is disclosed. A therapeutic formulation (102) may include particles of a biocompatible magnetic or magnetizable material that carry the therapeutic agent, or magnetically responsive cells. The therapeutic formulation (102) is intravenously administered to a mammalian subject. A portion of the formulation (102) is delivered to the proximity of a device (104) implanted in the vascular system of the subject by externally generating a magnetic field gradient (106) on the implantable device (104). The portion of the therapeutic formulation (102) not delivered to the proximity of the implantable device (104) is removed from the vascular system. The method allows for the repeated administration of the same or different therapeutic agent, and further, has the option of locally injecting, or alternatively, peripherally administering, the therapeutic agent.