The present invention is directed to polymeric materials made of biodegradable, bioabsorbable triblock copolymers and implantable devices (e.g., drug-delivery stents) containing such polymeric materials. The polymeric materials may also contain at least one therapeutic substance. The polymeric materials are formulated so as to improve the mechanical and adhesion properties, degradation, biocompatibility and drug permeability of such materials and, thus, implantable devices formed of such materials.