Drug formulation augments the therapeutic response of carboplatin administered through a lymphatic drug delivery system

Optimization of lymphatic drug delivery system with carboplatin for metastatic lymph nodes

Systemic chemotherapy is a common method for treatment of metastatic lymph nodes (LNs), but it has low tissue selectivity and high toxicity. Lymphatic drug delivery system (LDDS) is a novel approach to treat and prevent LN metastases. In a previous study, it was found that the increase of osmotic pressure with varied viscosity of the drug reagent enhances drug retention in the LNs. Here, we optimized the administration conditions to achieve a long-term therapeutic response by varying the dosages and injection rate, using the optimized osmotic pressure and varied viscosity of drug reagent for LDDS. A metastatic LN mouse model was created with MXH10/Mo/lpr mice. Luciferase labelled FM3A mouse mammary carcinoma cells were inoculated in subiliac LN (SiLN) to induce metastasis to the proper axillary LN (PALN). 4 days post tumor cell inoculation, carboplatin (CBDCA) was injected into the tumor-bearing SiLN under different administration conditions. Superior drug retention was observed in the group that received two-doses of CBDCA solution adjusted to an osmotic pressure and viscosity of 1897 kPa and 12 mPa·s, at an injection rate of 10 µL/min. Furthermore, this effect persisted for 42 days. This effect was accompanied by an upregulated expression of CD8, IL-12a, and IFN-γ in the spleen. These results suggest that dual-dose administration at 10 µL/min with hyper-osmotic and high viscosity formulation is optimal and can improve the long-term therapeutic efficacy of LN metastasis.

Development of an intranodal drug delivery system using a mouse model with lymphadenopathy: novel discoveries and clinical application

INTRODUCTION

The low drug delivery rate of systemic chemotherapy to metastatic lymph nodes (LNs) may be due to tumor growth without tumor neovascularization in the LNs, loss of existing blood vessels and lymph sinuses due to the tumor growth, and increased intranodal pressure. The lymphatic drug delivery system (LDDS) is a method of injecting anticancer drugs directly into the LNs and can overcome these problems. The world's first specific clinical study using the LDDS for head and neck cancer started in 2024 in Japan. In this review, the background of the development of LDDS up to the present clinical trials is described.

AREAS COVERED

The MXH10/Mo-lpr/lpr (MXH10/Mo/lpr) recombinant inbred model mouse, vascular and lymphatic flow through LNs, the clinical N0 (cN0) LN model, preclinical studies of the LDDS, and its clinical application to treat head and neck cancer.

EXPERT OPINION

Conventionally, hematogenous and lymphatic administration have been the focus of attention for drug delivery to LNs. The LDDS is a method for injecting drugs directly to LNs, so it is important to develop a solvent and injecting method that can increase the uniformity of drug distribution within LNs.

Docetaxel administered through a novel lymphatic drug delivery system (LDDS) improved treatment outcomes for lymph node metastasis

Recently, sentinel lymph nodes (LNs) have been recognized as a starting point of hematogenous metastasis; thus, an increase in the control rate of LN metastasis is expected to improve the survival rate. Although surgical treatment and radiation therapy are commonly used for the radical treatment of LNs, these treatments are associated with lymphedema, pain, and an extended hospital stay. In a recent mouse study, activation of metastatic tumors in distant organs was reported after removing LNs, with or without metastasis to the LNs. Thus, there is the necessity for cancer treatment that can replace LN removal. Here, we evaluated the treatment efficacy of lymphatic drug delivery system (LDDS) with osmotic pressure and viscosity escalated Docetaxel at the early stage of LN metastasis. MXH10/Mo/lpr mice were inoculated with mouse breast cancer cells into Subiliac LN to create the metastatic mouse model. Docetaxel was injected into mouse mammary carcinoma cells inoculated LN as a single shot (SS) or double shot (DS) to understand the therapeutic mechanism of a single shot or double shot intervention using an in vivo imaging system, histology, and qPCR. The results showed that the DS administration of docetaxel at 1,960 kPa (12 mPa∙s) had better therapeutic outcomes with increased complete response and improved survival with reduced adverse events. The results also revealed that administration of a DS of docetaxel enhances differentiation of T helper cells, and improves survival and therapeutic outcomes. From a safety perspective, LDDS-administered DS of low-concentration docetaxel without any other anticancer treatments to LNs a novel approach to cancer management of LN metastasis. We emphasize that LDDS is a groundbreaking method of delivering anticancer drugs specifically to cancer susceptible LNs and is designed to enhance the effectiveness of cancer treatment while minimizing side effects.

Metastatic lymph node targeted CTLA4 blockade: a potent intervention for local and distant metastases with minimal ICI-induced pneumonia

BACKGROUND

Immune checkpoint blockade (ICB) elicits a strong and durable therapeutic response, but its application is limited by disparate responses and its associated immune-related adverse events (irAEs). Previously, in a murine model of lymph node (LN) metastasis, we showed that intranodal administration of chemotherapeutic agents using a lymphatic drug delivery system (LDDS) elicits stronger therapeutic responses in comparison to systemic drug delivery approaches, while minimizing systemic toxicity, due to its improved pharmacokinetic profile at the intended site. Importantly, the LN is a reservoir of immunotherapeutic targets. We therefore hypothesized that metastatic LN-targeted ICB can amplify anti-tumor response and uncouple it from ICB-induced irAEs.

METHODS

To test our hypothesis, models of LN and distant metastases were established with luciferase expressing LM8 cells in MXH10/Mo-lpr/lpr mice, a recombinant inbred strain of mice capable of recapitulating ICB-induced interstitial pneumonia. This model was used to interrogate ICB-associated therapeutic response and immune related adverse events (irAEs) by in vivo imaging, high-frequency ultrasound imaging and histopathology. qPCR and flowcytometry were utilized to uncover the mediators of anti-tumor immunity.

RESULTS

Tumor-bearing LN (tbLN)-directed CTLA4 blockade generated robust anti-tumor response against local and systemic metastases, thereby improving survival. The anti-tumor effects were accompanied by an upregulation of effector CD8T cells in the tumor-microenvironment and periphery. In comparison, non-specific CTLA4 blockade was found to elicit weaker anti-tumor effect and exacerbated ICI-induced irAEs, especially interstitial pneumonia. Together these data highlight the importance of tbLN-targeted checkpoint blockade for efficacious response.

CONCLUSIONS

Intranodal delivery of immune checkpoint inhibitors to metastatic LN can potentiate therapeutic response while minimizing irAEs stemming from systemic lowering of immune activation threshold.