Development and Pre-clinical Feasibility of a Catheter-Based Platform for Interventional Phase-0 Drug Response...

To develop and validate a percutaneous Interventional Drug Response Assay (IDRA) catheter capable of intratumoral drug microdosing, adhesive stabilization, and subsequent biopsy retrieval of drug-exposed tissue, enabling minimally invasive in situ drug response measurements.

The IDRA catheter was designed as a modular platform allowing image-guided insertion, adhesive-based stabilization, microdose drug delivery into four discrete tissue regions, and suction-assisted biopsy retrieval. Feasibility and functionality were assessed across three ex vivo models: a gelatin phantom (n = 15), pork loin (n = 15), and rabbit VX-2 tumors (n = 15), as well as a rabbit VX-2 in vivo model (n = 2). Endpoints included proportion of drug reservoirs yielding intact tissue, sample thickness, and stabilization force. Success was defined as retrieval of ≥ 75% of drug regions with ≥ 3 drug sites per catheter and stabilization within a target force range of 1.5-4 N.

Ex vivo success rates were 100% (15/15 catheters) in phantom, 80% (12/15) in pork loin, and 80% (12/15) in VX-2 tumors. Mean tissue thickness exceeded 500 µm in all models (phantom: 860 ± 233 µm; loin: 589 ± 261 µm; VX-2: 637 ± 271 µm). Stabilization forces were within the target range across all tissue types (phantom: 3.4 ± 0.5 N; loin: 2.5 ± 0.6 N; VX-2: 2.8 ± 0.6 N). In vivo, 3-4 drug regions were successfully retrieved per catheter without complications.

The IDRA catheter achieved predefined functional endpoints across ex vivo and in vivo models, demonstrating early mechanical and procedural feasibility. If biologically validated, this could serve as a non-surgical platform for microdose-based early human drug response and biomarker testing and personalized oncology applications.