Combination Therapy of Pulsed-Wave Ultrasound Hyperthermia and Immunostimulant OK-432 Enhances Systemic Antitumor Immunity for Cancer Treatment

Abscopal effect of focused ultrasound combined immunotherapy in animal solid tumor model: a systematic reviews and meta-analysis

Introduction

The abscopal effect, a systemic anti-tumor response triggered by localized treatment, has gained attention but remains poorly understood. This study evaluates the efficacy and consistency of focused ultrasound (FUS) combined with immunotherapy in inducing the abscopal effect.

Methods

A systematic review and meta-analysis were conducted on preclinical studies using solid tumor models. Data on tumor response, immune modulation, and survival outcomes were analyzed to assess the combination therapy's effectiveness.

Results

FUS combined with immunotherapy enhanced anti-tumor responses at local and distant sites, with evidence of immune activation and increased abscopal effect rates. However, heterogeneity across tumor models and protocols was observed.

Discussion

The findings provide a theoretical basis for FUS-immunotherapy combinations in cancer treatment, while emphasizing the need for standardized protocols and further research to elucidate underlying mechanisms.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023460710.

Ultrasound-Guided High-Intensity Focused Ultrasound Combined With PD-1 Blockade in Patients With Liver Metastases From Lung Cancer: Protocol for a Single-Arm Phase 2 Trial

BACKGROUND

While immunotherapy has revolutionized oncological management, its efficacy in lung cancer patients with liver metastases remains limited, potentially due to the unique immunosuppressive microenvironment of the liver. Local liver treatment has been shown to enhance the immunotherapy response, and high-intensity focused ultrasound (HIFU), a minimally invasive local treatment, has demonstrated promising results in combination with immunotherapy. However, clinical data regarding HIFU in lung cancer with liver metastases are limited.

OBJECTIVE

We designed the HILL (Ultrasound-Guided High-Intensity Focused Ultrasound Combined With PD-1 Blockade in Patients With Liver Metastases From Lung Cancer) study to investigate the effectiveness and safety of HIFU in combination with immunotherapy for lung cancer with liver metastases.

METHODS

The HILL study is a single-armed, single-center, phase 2 clinical trial that will enroll 30 patients with lung cancer and liver metastases. The treatment regimen involves administering HIFU to liver metastases 1 week before the first dose of a programmed cell death protein (PD)-1 blockade, which is then administered every 3 weeks. The primary aim is to determine the overall response rate based on immune-related response criteria. Secondary aims include safety, progression-free survival, overall response, overall survival, and quality of life. Exploratory studies will also be conducted using whole blood, plasma, archival cancer tissue, and tumor biopsies during progression or relapse to identify potential biomarkers.

RESULTS

The study was funded on March 14, 2022, and received ethical approval on April 27, 2022. Clinical trial registration was completed by June 10, 2022, with participant recruitment beginning on July 10, 2022. Data collection commenced on July 14, 2022, with the enrollment of the first patient. By April 2024, 6 participants had been recruited. The results are expected to be published in December 2026.

CONCLUSIONS

This study seeks to improve treatment outcomes for lung cancer patients with liver metastases by combining HIFU and PD-1 inhibition. The study also aims to identify potential biomarkers through exploratory research that can aid in selecting patients for optimized outcomes in the future.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2200061076; https://www.chictr.org.cn/showproj.html?proj=170967.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/59152.

Ultrasound-induced immune responses in tumors: A systematic review and meta-analysis

Ultrasound is widely used in the diagnosis and therapy of cancer. Tumors can be treated by thermal or mechanical tissue ablation. Furthermore, tumors can be manipulated by hyperthermia, sonodynamic therapy and sonoporation, e.g., by increasing tumor perfusion or the permeability of biological barriers to enhance drug delivery. These treatments induce various immune responses in tumors. However, conflicting data and high heterogeneity between experimental settings make it difficult to generalize the effects of ultrasound on tumor immunity. Therefore, we performed a systematic review to answer the question: "Does ultrasound alter the immune reaction of peripheral solid tumors in humans and animals compared to control conditions without ultrasound?" A systematic literature search was performed in PubMed, EMBASE, and Web of Science and 24,401 potentially relevant publications were identified. Of these, 96 publications were eligible for inclusion in the systematic review. Experiments were performed in humans, rats, and mice and focused on different tumor types, primarily breast and melanoma. We collected data on thermal and non-thermal ultrasound settings, the use of sono-sensitizers or sono-enhancers, and anti-tumor therapies. Six meta-analyses were performed to quantify the effect of ultrasound on tumor infiltration by T cells (cytotoxic, helper, and regulatory T cells) and on blood cytokines (interleukin-6, interferon-γ, tumor necrosis factor-α). We provide robust scientific evidence that ultrasound alters T cell infiltration into tumors and increases blood cytokine concentrations. Furthermore, we identified significant differences in immune cell infiltration based on tumor type, ultrasound settings, and mouse age. Stronger effects were observed using hyperthermia in combination with sono-sensitizers and in young mice. The latter may impair the translational impact of study results as most cancer patients are older. Thus, our results may help refining ultrasound parameters to enhance anti-tumor immune responses for therapeutic use and to minimize immune effects in diagnostic applications.

Recent advances of ultrasound-responsive nanosystems in tumor immunotherapy

Immunotherapy has revolutionized cancer treatment by boosting the immune system and preventing disease escape mechanisms. Despite its potential, challenges like limited response rates and adverse immune effects impede its widespread clinical adoption. Ultrasound (US), known for its safety and effectiveness in tumor diagnosis and therapy, has been shown to significantly enhance immunotherapy when used with nanosystems. High-intensity focused ultrasound (HIFU) can obliterate tumor cells and elicit immune reactions through the creation of immunogenic debris. Low-intensity focused ultrasound (LIFU) bolsters tumor immunosuppression and mitigates metastasis risk by concentrating dendritic cells. Ultrasonic cavitation (UC) produces microbubbles that can transport immune enhancers directly, thus strengthening the immune response and therapeutic impact. Sonodynamic therapy (SDT) merges nanotechnology with immunotherapy, using specialized sonosensitizers to kill cancer cells and stimulate immune responses, increasing treatment success. This review discusses the integration of ultrasound-responsive nanosystems in tumor immunotherapy, exploring future opportunities and current hurdles.

Hyperthermia Treatment as a Promising Anti-Cancer Strategy: Therapeutic Targets, Perspective Mechanisms and Synergistic Combinations in Experimental Approaches

Despite recent developments in diagnosis and treatment options, cancer remains one of the most critical threats to health. Several anti-cancer therapies have been identified, but further research is needed to provide more treatment options that are safe and effective for cancer. Hyperthermia (HT) is a promising treatment strategy for cancer because of its safety and cost-effectiveness. This review summarizes studies on the anti-cancer effects of HT and the detailed mechanisms. In addition, combination therapies with anti-cancer drugs or natural products that can effectively overcome the limitations of HT are reviewed because HT may trigger protective events, such as an increase of heat shock proteins (HSPs). In the 115 reports included, the mechanisms related to apoptosis, cell cycle, reactive oxygen species, mitochondrial membrane potential, DNA damage, transcription factors and HSPs were considered important. This review shows that HT is an effective inducer of apoptosis. Moreover, the limitations of HT may be overcome using combined therapy with anti-cancer drugs or natural products. Therefore, appropriate combinations of such agents with HT will exert maximal effects to treat cancer.