The present invention is directed to a flowable composition that is suitable for use as a controlled release implant. The flowable composition includes a biodegradable thermoplastic polyester that is at least substantially insoluble in aqueous medium or body fluid. The flowable composition also includes a biocompatible polar aprotic solvent. The biocompatible polar aprotic solvent is miscible to dispersible in aqueous medium or body fluid. The flowable composition also includes leuprolide acetate. The present invention is also directed to a method for forming the flowable composition. The present invention is also directed to a biodegradable implant formed in situ, in a patient. The biodegradable implant is formed by injecting a flowable composition within the body of the patient and allowing the biocompatible polar aprotic solvent to dissipate to produce a solid biodegradable implant. The present invention is also directed to a method of forming a biodegradable implant in situ, in a living patient. The method includes injecting a flowable composition within the body of a patient and allowing the biocompatible polar aprotic solvent to dissipate to produce a solid biodegradable implant. The present invention is also directed to a method of treating cancer in a patient. The method includes administering to the patient in need of such treatment an effective amount of a flowable composition of the present invention. The present invention is also directed to a method of reducing LHRH levels in a patient. The method includes administering to the patient in need of such LHRH reduction an effective amount of a flowable composition of the present invention. The present invention is also directed to a kit. The kit includes a first container and a second container. The first container includes a composition that includes a biodegradable thermoplastic polyester and a biocompatible polar aprotic solvent. The second container includes leuprolide acetate. The present invention is
