TIP-27. An assessment of the Tumor Monorail Device (TMD) for repeated sampling as part of a trial evaluating the combination of D2C7-IT and an Fc-engineered anti-CD40 monoclonal antibody (2141-V11) administered intratumorally via convection-enhanced delivery (CED) and cervical perilymphatic injections (CPLIs) of 2141-V11 in recurrent glioblastoma (rGBM) patients

BACKGROUND The TMD is a surgically implanted catheter system that remains in place after tumor resection. The TMD is not used to deliver therapy but serves as a platform to monitor changes in the tumor environment post-treatment, potentially enabling researchers to gather more precise longitudinal data about the tumor and tumor microenvironment than imaging and other currently used evaluation tools. This could potentially offer critical insight into treatment efficacy and the biology of recurrence. To investigate the feasibility of this novel technology, we included a TMD arm to the currently enrolling trial evaluating the safety and efficacy of the combination of D2C7-IT+2141-V11 CED followed by repeated subcutaneous CPLIs of 2141-V11 ipsilateral to the tumor in rGBM (NCT04547777). METHODS Eligibility include adult patients with solitary supratentorial rGBM, IDH wild-type; ≥ 4weeks after chemotherapy, bevacizumab, or investigational agent; adequate organ function; KPS ≥70%, and an area of non-enhancing disease amenable for TMD implantation. Patients undergo TMD implantation into non-enhancing disease adjacent to the tumor to be infused via CED. Two weeks later, patients are treated with D2C7-IT (166μg) and 2141-V11 (3mg), both infused via CED, followed by CPLI of 2141-V11 at weeks 2 and 4 post-D2C7-IT+2141-V11 CED, followed by every 4 weeks for 1 year and then every 4-6 weeks. The TMD is sampled at each study visit. Result: The TMD arm was recently opened and is actively accruing patients. One patient had TMD implantation so far, with no untoward side effect from the device and TMD sampling at 8 indepent timepoints. CONCLUSION Enrollment, safety and results from the repeated TMD collection will be updated.