Drug coated balloon catheters for nonvascular strictures

Abstract

Embodiments of the present invention provide a method for treatment of nonvascular body lumen strictures such as benign prostatic hyperplasia (BPH), urethral strictures, ureteral strictures, prostate cancer, esophageal strictures, sinus strictures, biliary tract strictures, asthma and chronic obstructive pulmonary disease (COPD). The method involves delivering, preferably via drug coated balloon catheters, of anti-inflammatory and anti-proliferative drugs (rapamycin or paclitaxel and their analogues) and one or more additives.

What is claimed is: 
     
         1 . A method for treating a stricture in a nonvascular body lumen, the method comprising:
 inserting a balloon catheter to a target site in the stricture of a nonvascular body lumen, the balloon catheter comprising
 a balloon comprising a coating layer overlying external surfaces of the balloon, wherein the coating layer comprises
 a water-soluble first additive that comprises more than one hydroxyl group, wherein the water-soluble first additive has a molecular weight of 50 to 750, 
 a water-soluble second additive that is different than the first water-soluble additive and that comprises more than one hydroxyl group, wherein the water-soluble second additive has a molecular weight of 750 to 1,000, and 
 an initial drug load of a hydrophobic therapeutic agent; 
 
   inflating the balloon at least until the coating layer contacts walls of the nonvascular body lumen at the target site;   deflating the balloon after the inflation period; and   withdrawing the balloon catheter from the nonvascular body lumen.   
     
     
         2 . The method of  claim 1 , wherein the hydrophobic therapeutic agent is chosen from paclitaxel, paclitaxel analogues, rapamycin, rapamycin analogues, and combinations thereof 
     
     
         3 . The method of  claim 1 , wherein the hydrophobic therapeutic agent is chosen from rapamycin, rapamycin analogues, or a combination thereof. 
     
     
         4 . The method of  claim 1 , wherein the nonvascular body lumen is an esophagus, airway, sinus, trachea, colon, biliary tract, urinary tract, urethra, ureter, or a combination thereof. 
     
     
         5 . The method of  claim 1 , wherein the nonvascular body lumen is a urethra, a ureter, or a combination thereof. 
     
     
         6 . The method of  claim 1 , wherein the method further treats benign prostatic hyperplasia, and the method comprises inserting the balloon catheter to the target site in the stricture of a nonvascular body lumen that is the urethra, wherein the target site in the stricture of the nonvascular body lumen is within a prostate. 
     
     
         7 . The method of  claim 1 , wherein the initial drug load is from 1 to 20 micrograms of the hydrophobic therapeutic agent per square millimeter of the balloon. 
     
     
         8 . The method of  claim 1 , wherein the initial drug load is from 1 to 6 micrograms of the hydrophobic therapeutic agent per square millimeter of the balloon. 
     
     
         9 . The method of  claim 1 , wherein the initial drug load is of from 2 to 6 micrograms of the hydrophobic therapeutic agent per square millimeter of the balloon 
     
     
         10 . The method of  claim 1 , wherein a weight ratio in the coating layer of the combination of the water-soluble first additive and the water-soluble second additive to the initial drug load is 0.2:1 to 0.8:1 
     
     
         11 . The method of  claim 1 , wherein the balloon comprises a uniform circular cross-section perpendicular to a longitudinal direction of the balloon. 
     
     
         12 . The method of  claim 1 , wherein the coating layer is a uniform coating layer. 
     
     
         13 . The method of  claim 1 , wherein during inflation the coating layer makes uniform direct pressure contact with the stricture to release the therapeutic agent rapidly with the uniform direct pressure contact. 
     
     
         14 . The method of  claim 1 , wherein the balloon comprises a polyester, a polyamide, a nylon 12, a nylon 11, a polyamide 12, a block copolymer of a polyether and a polyamide, a polyether block amide, a polyurethane, a block copolymer of a polyether and a polyester, or a combination thereof, 
     
     
         15 . The method of  claim 1 , wherein the combination of the water-soluble first and second additives promote rapid release of the hydrophobic therapeutic agent from the balloon at the target site during an inflation period; 
     
     
         16 . The method of  claim 1 , wherein the inflation period is from 0.1 minutes to 10 minutes. 
     
     
         17 . The method of  claim 1 , wherein after the withdrawing, the balloon comprises residual drug amount of less than 45% of the initial drug load. 
     
     
         18 . The method of  claim 1 , wherein the coating layer is free of iodine covalent-bonded contrast agents, dyes, oils, and lipids. 
     
     
         19 . The method of  claim 1 , wherein the hydrophobic therapeutic agent is free of enclosure in micelles and liposomes and is free of encapsulation in polymer particles. 
     
     
         20 . A method for treating benign prostatic hyperplasia, the method comprising:
 inserting a balloon catheter to a target site, wherein the target site is a stricture in a urethra, wherein the target site in the stricture of the nonvascular body lumen is within a prostate, the balloon catheter comprising
 a balloon comprising a coating layer overlying a material of the balloon, wherein the coating layer comprises
 a water-soluble first additive that comprises more than one hydroxyl group, wherein the water-soluble first additive has a molecular weight of 50 to 750, 
 a water-soluble second additive that is different than the first water-soluble additive and that comprises more than one hydroxyl group, wherein the water-soluble second additive has a molecular weight of 750 to 1,000, 
 an initial drug load of a hydrophobic therapeutic agent; 
 
   inflating the balloon at least until the coating layer contacts walls of the nonvascular body lumen at the target site to release the hydrophobic therapeutic agent from the balloon at the target site during an inflation period;   deflating the balloon after the inflation period; and   withdrawing the balloon catheter from the nonvascular body lumen.