Neurodegenerative and malignant diseases of the central nervous system affect millions of Americans. These diseases are often devastating and difficult to treat, and effective drug delivery remains a significant challenge. Infusion of drugs nto the brain parenchyma using convection-enhanced delivery (CED) allows direct treatment of lesions, circumventing the blood brain barrier. In particular, important new treatments and diseases call for large regions of brain to be subjected to therapeutic doses. Multiple clinical trials have been conducted using CED to deliver large volumes of chemotherapy and immunotoxins in patients with gliomas, but actual drug delivery to the tumor has been poor for several reasons including the unpredictable dispersion of the drug in the tissue. These adverse events result in reduced efficacy and increased toxicity. To overcome the limitations associated with conventional CED catheters in heterogeneous tissue, the Applicants have developed a macroporous hollow fiber catheter (maPHFC) for improved drug delivery. Hypothesis: The Applicants propose that maPHFCs will overcome the limitations of current CED catheters for the treatment of brain disorders requiring large distributions in tissue. Preliminary Data: In Applicant's prior research, porous hollow fiber catheters (PHFCs) showed superior performance in positioning, priming, and infusion as compared to conventional CED catheters. PHFCs produced less reflux in bench and large animal studies. In vitro and in vivo studies have shown the unique ability of the PHFC to traverse voids and distribute therapeutics across both sides of the void. An innovative macroporous PHFC (maPHFC) that provides several days of infusion of large molecules without occlusion has been developed and preliminarily tested.
Specific Aims : With this proposed Phase I feasibility research, the Applicants expect to develop the maPHFC design to meet human use requirements for large infusions in acute settings and assess performance with bench and animal testing. Design verification testing will be conducted to facilitate eventual clinical studies.
Aim 1 : Finalize human maPHFC designs. maPHFC designs will be finalized to meet human use requirements based on expert design input. Key design changes from prior research will focus on improved priming, maPHFC stabilization during tunneling and optimization of the maPHFC design for large volume distribution.
Aim 2 : In vivo maPHFC comparative safety and infusion studies. maPHFC and control catheters will be evaluated in normal swine brains with MR tracer infusions. Results will be used to compare safety and volume of distribution.
Aim 3 : maPHFC design verification testing. The objective is to generate the test data required for FDA clinical study approvals.
Effective drug delivery of large volumes of solutions containing therapeutic agents into the brain remains a significant obstacle to achieving clinical efficacy of therapies for neurodegenerative and malignant diseases affecting the central nervous system. The Applicants have developed novel porous hollow fiber catheters, which demonstrate more uniform and better distribution of infusates in tissue than standard of care catheters. In this project, bench and animal studies will be conducted, followed by design verification testing to generate data for FDA clinical study approvals.
|Brady, Martin L; Raghavan, Raghu; Mata, Jaime et al. (2018) Large-Volume Infusions into the Brain: A Comparative Study of Catheter Designs. Stereotact Funct Neurosurg 96:135-141|