Pressure-Enabled Drug Delivery System Enhances Nelitolimod Efficacy in Liver Tumors
Key Insights
Researchers at Brown University and Trisalus Life Sciences demonstrated that pressure-enabled drug delivery (PEDD) significantly enhanced nelitolimod distribution in liver tumors (search) compared to conventional catheter delivery methods.
The PEDD system delivered nelitolimod with greater signal intensity and distribution in target tissue, resulting in significantly reduced tumor progression compared to systemic administration in preclinical models.
Treatment with PEDD-delivered nelitolimod promoted anti-tumor immunity by significantly reducing immunosuppressive myeloid-derived suppressor cells and increasing cytotoxic CD8+ T cells (search) within liver metastases.
Researchers have developed a pressure-enabled drug delivery (PEDD) system that significantly enhances the therapeutic efficacy of nelitolimod, an immunomodulatory agent, in treating liver tumors (search). The study, conducted by teams at Brown University and Trisalus Life Sciences, addresses critical delivery challenges that have limited the effectiveness of conventional treatment approaches for intrahepatic malignancies.
Enhanced Drug Distribution Through Pressure-Controlled Delivery
The research team compared PEDD with conventional microcatheter delivery methods using transgenic pigs with liver tumors (search). Results demonstrated that PEDD resulted in a significant increase in distribution and signal intensity—a surrogate for drug concentration—in target tissue compared to needle injection or standard catheter delivery in the oncopig model.
Near-infrared imaging revealed superior tissue distribution patterns when nelitolimod was delivered via the specialized PEDD infusion device. This enhanced delivery addresses a fundamental challenge in liver tumor treatment, where conventional systemic infusion may be inadequate due to high intra-tumoral pressure and unwanted distribution to non-target tissues.
Significant Tumor Reduction in Preclinical Models
In murine liver metastasis (search) models, single treatment with nelitolimod via PEDD significantly reduced tumor progression compared to systemic administration. The researchers developed the liver metastasis model by injecting MC38-Luc cells into C57/BL6 mouse spleens and treating with fluorescently labeled nelitolimod at 30 μg per mouse.
Tumor burden monitoring through in vivo imaging systems confirmed the superior efficacy of the pressure-controlled delivery approach. The enhanced therapeutic effect was attributed to improved drug penetration into both tumor tissue and the surrounding peri-tumoral parenchyma where target immune cells are located.
Immune Microenvironment Reprogramming
Flow cytometry analysis of liver CD45+ cells (search) revealed that PEDD delivery of nelitolimod significantly altered the tumor microenvironment. The treatment significantly reduced immunosuppressive myeloid-derived suppressor cells (MDSCs (search)) while increasing cytotoxic CD8+ T cells (search) within liver metastases.
These immune changes align with previous clinical and preclinical reports suggesting that nelitolimod favorably reprograms the tumor microenvironment to limit myeloid-induced immunosuppression and promote anti-tumor immunity. The enhanced delivery method appears to amplify these beneficial immunomodulatory effects.
Addressing Clinical Delivery Challenges
The research addresses specific limitations of current nelitolimod delivery methods. While direct tumoral needle injection of nelitolimod has shown encouraging outcomes in patients with superficial malignancies, including cutaneous melanoma (search), this approach may not be suitable for primary and metastatic liver tumors (search).
The challenges include the number and size of liver lesions and the strategic location of target immune cells in the peri-tumoral parenchyma. The PEDD system offers a potential solution by enabling targeted intra-arterial delivery with enhanced tissue penetration through controlled pressure application.
Technical Implementation and Monitoring
The study employed comprehensive monitoring approaches, including serum cytokine level analysis through Luminex technology and blood chemistry measurements to assess treatment effects. The pressure-controlled infusion system was successfully modeled in both large animal (oncopig) and murine settings, demonstrating scalability across different preclinical models.
The research team used both lobar and selective infusion approaches, providing flexibility in targeting different tumor locations and sizes. This technical versatility could prove crucial for clinical translation, where tumor characteristics vary significantly among patients.