Cisplatin/epinephrine injectable gel

Study of epirubicin sustained-release chemoablation in tumor suppression and tumor microenvironment remodeling

Introduction

Although intratumoral chemoablation can obtain an impressive therapeutic effect, there is still incomplete ablation and tumor recurrence in some patients. This could be due to the short retention time of the drug in the tumor, the limited distribution of intratumoral drugs, and, beyond that, the immunotolerance caused by the tumor microenvironment (TME). There is still an urgent need to find an optimal drug sustained-release carrier and figure out the impact of regional injection to TME.

Methods

In this study, we supposed to use polyethylene glycol (PEG) hydrogel as a drug carrier to improve the retention time of the drug to extend the exposure of tumor cells and investigate the feasibility of combination local Epirubicin injection with anti-PD-L1.

Results

The results revealed obvious tumor suppression based on the tumor volume and the inhibition time of tumor growth in the A549 lung cancer mouse model after local injection. Furthermore, the enhanced antitumor effects of the combination of systematic anti- programmed death ligand 1 (PD-L1) therapy with local chemoablation (EPI-GEL/PD-L1) for abscopal tumor reduction in the 4T1 breast model were also observed. Flow cytometry analysis of the tumor and blood samples showed significant variations in the proportions of PD-L1⁺ and CD3⁺CD8⁺PD-1⁺ cells before and after anti-PD-L1 therapy. On day 4 after local injection of the EPI gel, the expression of PD-L1 in abscopal tumors was upregulated, while the expression of PD-L1 in bilateral tumors in mice was significantly reduced after anti-PD-L1 treatment. The proportion of CD3⁺CD8⁺PD-1⁺ cells in the tumor and circulating blood in the EPI-GEL/PD-L1 group was decreased compared with that in the EPI-GEL (single injection of epirubicin) group.

Discussion

The combination of local injection of the chemoablation agent with anti-PD-L1 monoclonal antibody (mAb) therapy may strengthen the antitumor activity, and the use of PEG hydrogel as the drug carrier can extend the retention time of the chemoablation agent around the tumor, maintaining a long-term tumor-killing activity.

Human intratumoral therapy: Linking drug properties and tumor transport of drugs in clinical trials

Cancer therapies aim to kill tumor cells directly or engage the immune system to fight malignancy. Checkpoint inhibitors, oncolytic viruses, cell-based immunotherapies, cytokines, and adjuvants have been applied to prompt the immune system to recognize and attack cancer cells. However, systemic exposure of cancer therapies can induce unwanted adverse events. Intratumoral administration of potent therapies utilizes small amounts of drugs, in an effort to minimize systemic exposure and off-target toxicities. Here, we discuss the properties of the tumor microenvironment and transport considerations for intratumoral drug delivery. Specifically, we consider various tumor tissue factors and physicochemical factors that can affect tumor retention after intratumoral injection. We also review approved and clinical-stage intratumoral therapies and consider how the molecular and biophysical properties (e.g. size and charge) of these therapies influences intratumoral transport (e.g. tumor retention and cellular uptake). Finally, we offer a critical review and highlight several emerging approaches to promote tumor retention and limit systemic exposure of potent intratumoral therapies.

In Situ Drug Delivery to Breast Cancer-Associated Extracellular Matrix

The extracellular matrix (ECM) contributes to tumor progression through changes induced by tumor and stromal cell signals that promote increased ECM density and stiffness. The increase in ECM stiffness is known to promote tumor cell invasion into surrounding tissues and metastasis. In addition, this scar-like ECM creates a protective barrier around the tumor that reduces the effectiveness of innate and synthetic antitumor agents. Herein, clinically approved breast cancer therapies as well as novel experimental approaches that target the ECM are discussed, including in situ hydrogel drug delivery systems, an emerging technology the delivers toxic chemotherapeutics, gene-silencing microRNAs, and tumor suppressing immune cells directly inside the tumor. Intratumor delivery of therapeutic agents has the potential to drastically reduce systemic side effects experienced by the patient and increase the efficacy of these agents. This review also describes the opposing effects of ECM degradation on tumor progression, where some studies report improved drug delivery and delayed cancer progression and others report enhanced metastasis and decreased patient survival. Given the recent increase in ECM-targeting drugs entering preclinical and clinical trials, understanding and addressing the factors that impact the effect of the ECM on tumor progression is imperative for the sake of patient safety and survival outcome.

OncoGel (ReGel/paclitaxel)--clinical applications for a novel paclitaxel delivery system

Cancer treatment regimens often include multiple anticancer agents targeting different cellular mechanisms in delicate balance with associated toxicity. Drug delivery systems offer a unique tool in the treatment of cancer, and applications in the local treatment of cancer have demonstrated utility in providing sustained high local concentrations at the tumor site while minimizing systemic drug levels. Treatment options for local cancer therapy are focused on indications where targeted activity may result in improved patient outcomes such as increased local control and decreased metastatic potential. Targeted therapies may also enhance response to combination anticancer regimens. OncoGel, a controlled-release depot formulation of paclitaxel in ReGel, has been evaluated in numerous nonclinical studies. Results from these studies demonstrated OncoGel's ability to physically target paclitaxel to the tumor site with very little reaching the circulation, resulting in an acceptable safety profile with dose-limiting toxicities being local in nature. In addition, OncoGel demonstrated efficacy as a stand-alone treatment and synergistic activity in combination therapies. Clinical studies in superficially-palpable tumors and esophageal carcinoma confirmed local paclitaxel release from OncoGel in patients. OncoGel's ability to improve current treatment options for esophageal and brain cancers is being further evaluated.

RADPLAT: an alternative to surgery?

Head and neck cancer frequently presents at a late stage, leading to a poor prognosis despite optimal treatment with surgery and/or radiotherapy. Chemotherapy for advanced disease has shown little benefit as a single-modality treatment, and the use of concurrent chemoradiation is limited by problems with severe toxicity at higher doses. RADPLAT is the acronym used to describe a new technique, combining intra-arterial delivery of cisplatin with systemic neutralization by i.v. sodium thiosulphate, and concurrent radiotherapy. This allows very high cisplatin dose intensities to be used while potentially minimizing adverse systemic effects. Initial results suggest that excellent locoregional control rates are achievable in patients with unresectable disease, with a favorable side-effect profile when compared with conventional chemoradiation protocols. In addition, RADPLAT may potentially be of benefit in selected patients with resectable disease, allowing for preservation of organ function and quality of life without compromising locoregional control or survival. While current phase II data are encouraging, phase III randomized controlled trials are required in order to directly compare RADPLAT with i.v. chemoradiation therapy, the current standard of care. This article reviews the evolution of the RADPLAT concept, from initial clinical trials to its current application in the treatment of patients with advanced head and neck cancer.

Intratumoral NAMI-A treatment triggers metastasis reduction, which correlates to CD44 regulation and tumor infiltrating lymphocyte recruitment

Intratumor (i.t.) injection of 35 mg/kg/day NAMI-A for six consecutive days to CBA mice bearing i.m. implants of MCa mammary carcinoma reduces primary tumor growth and particularly lung metastasis formation, causing 60% of animals to be free of macroscopically detectable metastases. The i.t. treatment allows study of the effects of NAMI-A on in vivo tumor cells exposed to millimolar concentrations for a relatively prolonged time. Under these conditions, NAMI-A reduces the number of CD44+ tumor cells and changes tumor cell phenotype to a lower aggressive behavior, as shown by scanning electron microscopy analysis. On primary tumor site, NAMI-A causes unbalance between 2n and aneuploid cells in favor of lymphocytes. Furthermore, in tumor tissue, nitric oxide production is increased and active matrix metalloproteinase 9 is decreased, and these effects are accompanied by a reduced hemoglobin concentration. These data are in agreement with the reduction of tumor invasion and metastasis and suggest the therapeutic usefulness of NAMI-A in neoadjuvant or tumor reduction treatments for preventing metastasis formation. These data further stress the usefulness of intratumor treatments as experimental preclinical model for studying in vivo the mechanism of tumor cell interactions after prolonged exposure to ruthenium-based compounds to be developed for metastasis inhibition.

Intralesional chemotherapy for head and neck carcinoma: a review of the literature

In the last decade chemotherapy has gained widespread acceptance in the treatment of oral and pharyngeal cancer. Current standard treatment for advanced lesions consists of concomitant radiation and chemotherapy. This approach has provided marginal improvement of prognosis for Stage III-IV disease. Recent studies have explored the idea that locally delivered cytotoxic drugs could further improve prognosis in this patient population. We review this literature with the objective of popularizing these data and suggesting future directions for treatment and clinical research for head and neck cancer.

The role of isolated limb perfusion for melanoma confined to the extremities

Isolated limb perfusion with Melphalan is the best treatment option to control symptomatic multiple small in-transit metastases. When lesions are bulky, Isolated Limb Perfusion (ILP) with Tumor Necrosis Factor (TNF) + Melphalan is superior as in soft tissue sarcoma. TNF changes the pathophysiology, greatly enhances the uptake of Melphalan and destructs selectively the vasculature of large tumors. To date, ILP is not indicated in an adjuvant setting.

Intratumoral cisplatin/adrenaline injectable gel for the treatment of patients with cutaneous and soft tissue metastases of malignant melanoma

Local therapies have been highly effective in the treatment of melanoma. The objective of this study was to evaluate the use of a novel intralesional chemotherapy - cisplatin/adrenaline injectable gel - for the treatment of refractory or recurrent cutaneous and soft tissue melanoma metastases. The gel is injected directly into the lesion and delivers high concentrations of cisplatin at the injection site, where it is retained for extended periods, with little systemic exposure. A total of 28 patients with refractory or recurrent melanoma were enrolled in this open-label, multicentre study. Of these, 25 patients with 244 lesions were evaluable for efficacy. Lesions were injected with 0.5 ml (2 mg cisplatin + 0.05 mg adrenaline) of gel/cm(3) of tumour. Patients received up to six weekly treatments within an 8 week period. The objective response rate (complete responses [CRs] plus partial responses [PRs]) for all the tumours treated (1-72 per patient) was 53% (130 out of 244; 114 CRs, 16 PRs). The response rate for the target tumours (i.e. each patient's single, most symptomatic, largest or most threatening tumour) was 44%. The median response duration for all tumours was 347 days (range 30-783 days) and median number of treatments per tumour was five (range one to twelve). Systemic toxicity was negligible; local adverse reactions such as erythema, necrosis or pain occurred frequently, but were easily managed in most cases. In conclusion, cisplatin/adrenaline injectable gel was well tolerated, easy to administer, and effective in treating metastatic melanoma confined to the skin or soft tissues.