A composition for delivery of a therapeutic agent is provided. The composition comprises: (a) a biocompatible block
copolymer comprising one or more elastomeric blocks and one or more
thermoplastic blocks and (b) a therapeutic agent, wherein the block
copolymer is loaded with the therapeutic agent. The block
copolymer is preferably of the formula X—(AB)n, where A is an elastomeric block, B is a
thermoplastic block, n is a positive whole number and X is a seed molecule. The elastomeric blocks are preferably
polyolefin blocks, and the
thermoplastic blocks are preferably selected from vinyl aromatic blocks and
methacrylate blocks. According to another aspect of the invention, a
medical device is provided, at least a portion of which is insertable or implantable into the body of a patient. The
medical device comprises (a) the above biocompatible block copolymer and (b) a therapeutic agent, wherein the block copolymer is loaded with the therapeutic agent. According to another aspect of the present invention, a method of treatment is provided in which the above device is implanted or inserted into a patient, resulting in the release of therapeutic agent in the patient over an extended period. According to yet another aspect of the invention, a coated
medical device is provided which comprises: (a) an intravascular or intervascular medical device and (b) a
coating over at least a portion of the intravascular or intervascular a medical device, wherein the
coating comprises the above biocompatible block copolymer.