An immunotherapy delivery device is provided including a catheter and a pressure modulating device fixed adjacent the distal end of the catheter. In accord with aspects of the device, the lumen of the catheter is coated to facilitate delivery of a healthy immunotherapy agent. A method for delivering an immunotherapy agent to a tumor includes advancing the delivery device into a vessel of a patient, and infusing the agent under pressure into the vessel to penetrate the tumor. The delivery device prevents reflux of the agent toward non-treatment sites.
