In vivo positionable filtration devices are provided that filter one or more therapeutic agents in blood flowing in a blood vessel. The filtration devices include an elongated member and a filtering component coupled to the elongated member. The elongated member and the filtering component are dimensioned for positioning within a blood vessel of a human or non-human animal. Further, the filtering component includes a filtration material to filter the one or more therapeutic agents from blood. Methods of in vivo filtration of one or more therapeutic agents are also provided. The methods include positioning a filtration device in a blood vessel of a body of a human or non-human animal, and administering a therapeutic agent upstream from the target tissue site to direct flow of the therapeutic agent to the target tissue site and then to the filtration device. The filtration device is positioned downstream from a target tissue site.