Interventional Radiology for Local Immunotherapy in Oncology

Regional and intratumoral adoptive T-cell therapy

Adoptive T-cell therapies (ACTs) including tumor-infiltrating lymphocytes and engineered T cells (transgenic T-cell receptor and chimeric antigen receptor T cells), have made an important impact in the field of cancer treatment over the past years. Most of these therapies are typically administered systemically in approaches that facilitate the elimination of hematologic malignancies. Therapeutical efficacy against solid tumors, however, with the exception of tumor-infiltrating lymphocytes against melanoma, remains limited due to several barriers preventing lymphocyte access to the tumor bed. Building upon the experience of regional administration in other immunotherapies, the regional administration of adoptive cell therapies is being assessed to overcome this challenge, granting a first round of access of the transferred T cells to the tumor niche and thereby ensuring their activation and expansion. Intralesional and intracavitary routes of delivery have been tested with promising antitumor objective responses in preclinical and clinical studies. Additionally, several strategies are being developed to further improve T-cell activity after reinfusing them back to the patient such as combinations with other immunotherapy agents or direct engineering of the transferred T cells, achieving long-term immune memory. Clinical trials testing different regional adoptive T-cell therapies are ongoing but some issues related to methodology of administration and correct selection of the target antigen to avoid on-target/off-tumor side-effects need to be further evaluated and improved. Herein, we discuss the current preclinical and clinical landscape of intratumoral and locoregional delivery of adoptive T-cell therapies.

Ultrasound and x-ray imageable poloxamer-based hydrogel for loco-regional therapy delivery in the liver

Intratumoral injections have the potential for enhanced cancer treatment efficacy while reducing costs and systemic exposure. However, intratumoral drug injections can result in substantial off-target leakage and are invisible under standard imaging modalities like ultrasound (US) and x-ray. A thermosensitive poloxamer-based gel for drug delivery was developed that is visible using x-ray imaging (computed tomography (CT), cone beam CT, fluoroscopy), as well as using US by means of integrating perfluorobutane-filled microbubbles (MBs). MBs content was optimized using tissue mimicking phantoms and ex vivo bovine livers. Gel formulations less than 1% MBs provided gel depositions that were clearly identifiable on US and distinguishable from tissue background and with minimal acoustic artifacts. The cross-sectional areas of gel depositions obtained with US and CT imaging were similar in studies using ex vivo bovine liver and postmortem in situ swine liver. The gel formulation enhanced multimodal image-guided navigation, enabling fusion of ultrasound and x-ray/CT imaging, which may enhance targeting, definition of spatial delivery, and overlap of tumor and gel. Although speculative, such a paradigm for intratumoral drug delivery might streamline clinical workflows, reduce radiation exposure by reliance on US, and boost the precision and accuracy of drug delivery targeting during procedures. Imageable gels may also provide enhanced temporal and spatial control of intratumoral conformal drug delivery.

Prospects of Synergy: Local Interventions and CAR T Cell Therapy in Solid Tumors

Chimeric antigen receptor T cell therapy has been established in the treatment of various B cell malignancies. However, translating this therapeutic effect to treat solid tumors has been challenging because of their inter-tumoral as well as intratumoral heterogeneity and immunosuppressive microenvironment. Local interventions, such as surgery, radiotherapy, local ablation, and locoregional drug delivery, can enhance chimeric antigen receptor T cell therapy in solid tumors by improving tumor infiltration and reducing systemic toxicities. Additionally, ablation and radiotherapy have proven to (re-)activate systemic immune responses via abscopal effects and reprogram the tumor microenvironment on a physical, cellular, and chemical level. This review highlights the potential synergy of the combined approaches to overcome barriers of chimeric antigen receptor T cell therapy and summarizes recent studies that may pave the way for new treatment regimens.

Intratumoral Injection of Immunotherapeutics: State of the Art and Future Directions

Systemic immunotherapies have led to tremendous progress across the cancer landscape. However, several challenges exist, potentially limiting their efficacy in the treatment of solid tumors. Direct intratumoral injection can increase the therapeutic index of immunotherapies while overcoming many of the barriers associated with systemic administration, including limited bioavailability to tumors and potential systemic safety concerns. However, challenges remain, including the lack of standardized approaches for administration, issues relating to effective drug delivery, logistical hurdles, and safety concerns specific to this mode of administration. This article reviews the biologic rationale for the localized injection of immunotherapeutic agents into tumors. It also addresses the existing limitations and practical considerations for safe and effective implementation and provide recommendations for optimizing logistics and treatment workflows. It also highlights the critical role that radiologists, interventional radiologists, and medical physicists play in intratumoral immunotherapy with respect to target selection, image-guided administration, and response assessment.

Pigs as Clinically Relevant Models for Synergizing Interventional Oncology and Immunotherapy

Traditionally, rodent cancer models have driven preclinical oncology research. However, they do not fully recapitulate characteristics of human cancers, and their size poses challenges when evaluating tools in the interventional oncologists' armamentarium. Pig models, however, have been the gold standard for validating surgical procedures. Their size enables the study of image-guided interventions using human ultrasound (US), computed tomography (CT), and magnetic resonance (MR) imaging platforms. Furthermore, pigs have immunologic features that are similar to those of humans, which can potentially be leveraged for studying immunotherapy. Novel pig models of cancer are being developed, but additional research is required to better understand both the pig immune system and malignancy to enhance the potential for pig models in interventional oncology research. This review aims to address the main advantages and disadvantages of using a pig model for interventional oncology and outline the specific characteristics of pig models that make them more suitable for investigation of locoregional therapies.

International guidelines for intratumoral and intranodal injection of NBTXR3 nanoparticles in head and neck cancers

BACKGROUND

An international multidisciplinary panel of experts aimed to provide consensus guidelines describing the optimal intratumoral and intranodal injection of NBTXR3 hafnium oxide nanoparticles in head and neck squamous cell carcinoma (HNSCC) of the oral cavity, oropharynx, and cervical lymph nodes and to review data concerning safety, feasibility, and procedural aspects of administration.

METHODS

The Delphi method was used to determine consensus. A 4-member steering committee and a 10-member monitoring committee wrote and revised the guidelines, divided into eight sections. An independent 3-member reading committee reviewed the recommendations.

RESULTS

After two rounds of voting, strong consensus was obtained on all recommendations. Intratumoral and intranodal injection was deemed feasible. NBTXR3 volume calculation, choice of patients, preparation and injection procedure, potential side effects, post injection, and post treatment follow-up were described in detail.

CONCLUSIONS

Best practices for the injection of NBTXR3 were defined, thus enabling international standardization of intratumoral nanoparticle injection.

Locoregional drug delivery for cancer therapy: Preclinical progress and clinical translation

Systemic drug delivery is the current clinically preferred route for cancer therapy. However, challenges associated with tumor localization and off-tumor toxic effects limit the clinical effectiveness of this route. Locoregional drug delivery is an emerging viable alternative to systemic therapies. With the improvement in real-time imaging technologies and tools for direct access to tumor lesions, the clinical applicability of locoregional drug delivery is becoming more prominent. Theoretically, locoregional treatments can bypass challenges faced by systemic drug delivery. Preclinically, locoregional delivery of drugs has demonstrated enhanced therapeutic efficacy with limited off-target effects while still yielding an abscopal effect. Clinically, an array of locoregional strategies is under investigation for the delivery of drugs ranging in target and size. Locoregional tumor treatment strategies can be classified into two main categories: 1) direct drug infusion via injection or implanted port and 2) extended drug elution via injected or implanted depot. The number of studies investigating locoregional drug delivery strategies for cancer treatment is rising exponentially, in both preclinical and clinical settings, with some approaches approved for clinical use. Here, we highlight key preclinical advances and the clinical relevance of such locoregional delivery strategies in the treatment of cancer. Furthermore, we critically analyze 949 clinical trials involving locoregional drug delivery and discuss emerging trends.

Act Local, Think Global: IR and Its Role in Immuno-Oncology in Hepatocellular Carcinoma

Interventional oncology (IO) is evolving rapidly. The treatment landscape of liver cancer is changing rapidly, and immunotherapy combinations have become the standard of care for most patients with advanced hepatocellular carcinoma (HCC). The higher response rates and improved outcomes observed with these agents are leading to initiatives for their earlier incorporation in the course of the disease, including in combination with ablative and transarterial treatment options. The intersectionality of systemic therapies and liver-directed approaches has allowed IO to be at the center stage of a rapidly evolving dynamic field across all stages of HCC. This review article will address the current state of treatment for advanced HCC and the incorporation of these options in both localized and advanced stages along with IO to further enhance the observed benefits.

Local and distant response to intratumoral immunotherapy assessed by immunoPET in mice

BACKGROUND

Despite the promising efficacy of immune checkpoint blockers (ICB), tumor resistance and immune-related adverse events hinder their success in cancer treatment. To address these challenges, intratumoral delivery of immunotherapies has emerged as a potential solution, aiming to mitigate side effects through reduced systemic exposure while increasing effectiveness by enhancing local bioavailability. However, a comprehensive understanding of the local and systemic distribution of ICBs following intratumoral administration, as well as their impact on distant tumors, remains crucial for optimizing their therapeutic potential.To comprehensively investigate the distribution patterns following the intratumoral and intravenous administration of radiolabeled anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and to assess its corresponding efficacy in both injected and non-injected tumors, we conducted an immunoPET imaging study.

METHODS

CT26 and MC38 syngeneic colorectal tumor cells were implanted subcutaneously on both flanks of Balb/c and C57Bl/6 mice, respectively. Hamster anti-mouse CTLA-4 antibody (9H10) labeled with zirconium-89 ([89Zr]9H10) was intratumorally or intravenously administered. Whole-body distribution of the antibody was monitored by immunoPET imaging (n=12 CT26 Balb/c mice, n=10 MC38 C57Bl/6 mice). Tumorous responses to injected doses (1-10 mg/kg) were correlated with specific uptake of [89Zr]9H10 (n=24). Impacts on the tumor microenvironment were assessed by immunofluorescence and flow cytometry.

RESULTS

Half of the dose was cleared into the blood 1 hour after intratumoral administration. Despite this, 7 days post-injection, 6-8% of the dose remained in the intratumoral-injected tumors. CT26 tumors with prolonged ICB exposure demonstrated complete responses. Seven days post-injection, the contralateral non-injected tumor uptake of the ICB was comparable to the one achieved through intravenous administration (7.5±1.7% ID.cm-3 and 7.6±2.1% ID.cm-3, respectively) at the same dose in the CT26 model. This observation was confirmed in the MC38 model. Consistent intratumoral pharmacodynamic effects were observed in both intratumoral and intravenous treatment groups, as evidenced by a notable increase in CD8+T cells within the CT26 tumors following treatment.

CONCLUSIONS

ImmunoPET-derived pharmacokinetics supports intratumoral injection of ICBs to decrease systemic exposure while maintaining efficacy compared with intravenous. Intratumoral-ICBs lead to high local drug exposure while maintaining significant therapeutic exposure in non-injected tumors. This immunoPET approach is applicable for clinical practice to support evidence-based drug development.

Intratumoral Immunotherapy: Is It Ready for Prime Time?

PURPOSE OF REVIEW

This review presents the rationale for intratumoral immunotherapy, technical considerations and safety. Clinical results from the latest trials are provided and discussed.

RECENT FINDINGS

Intratumoral immunotherapy is feasible and safe in a wide range of cancer histologies and locations, including lung and liver. Studies mainly focused on multi-metastatic patients, with some positive trials such as T-VEC in melanoma, but evidence of clinical benefit is still lacking. Recent results showed improved outcomes in patients with a low tumor burden. Intratumoral immunotherapy can lower systemic toxicities and boost local and systemic immune responses. Several studies have proven the feasibility, repeatability, and safety of this approach, with some promising results in clinical trials. The clinical benefit might be improved in patients with a low tumor burden. Future clinical trials should focus on adequate timing of treatment delivery during the course of the disease, particularly in the neoadjuvant setting.

Recent Studies and Progress in the Intratumoral Administration of Nano-Sized Drug Delivery Systems

Over the last 30 years, diverse types of nano-sized drug delivery systems (nanoDDSs) have been intensively explored for cancer therapy, exploiting their passive tumor targetability with an enhanced permeability and retention effect. However, their systemic administration has aroused some unavoidable complications, including insufficient tumor-targeting efficiency, side effects due to their undesirable biodistribution, and carrier-associated toxicity. In this review, the recent studies and advancements in intratumoral nanoDDS administration are generally summarized. After identifying the factors to be considered to enhance the therapeutic efficacy of intratumoral nanoDDS administration, the experimental results on the application of intratumoral nanoDDS administration to various types of cancer therapies are discussed. Subsequently, the reports on clinical studies of intratumoral nanoDDS administration are addressed in short. Intratumoral nanoDDS administration is proven with its versatility to enhance the tumor-specific accumulation and retention of therapeutic agents for various therapeutic modalities. Specifically, it can improve the efficacy of therapeutic agents with poor bioavailability by increasing their intratumoral concentration, while minimizing the side effect of highly toxic agents by restricting their delivery to normal tissues. Intratumoral administration of nanoDDS is considered to expand its application area due to its potent ability to improve therapeutic effects and relieve the systemic toxicities of nanoDDSs.

Immunomodulatory effect of locoregional therapy in the tumor microenvironment

Cancer immunotherapy appears to be a promising treatment option; however, only a subset of patients with cancer responds favorably to treatment. Locoregional therapy initiates a local antitumor immune response by disrupting immunosuppressive components, releasing immunostimulatory damage-associated molecular patterns, recruiting immune effectors, and remodeling the tumor microenvironment. Many studies have shown that locoregional therapy can produce specific antitumor immunity alone; nevertheless, the effect is relatively weak and transient. Furthermore, increasing research efforts have explored the potential synergy between locoregional therapy and immunotherapy to enhance the long-term systemic antitumor immune effect and improve survival. Therefore, further research is needed into the immunomodulatory effects of locoregional therapy and immunotherapy to augment antitumor effects. This review article summarizes the key components of the tumor microenvironment, discusses the immunomodulatory role of locoregional therapy in the tumor microenvironment, and emphasizes the therapeutic potential of locoregional therapy in combination with immune checkpoint inhibitors.

mRNAs encoding IL-12 and a decoy-resistant variant of IL-18 synergize to engineer T cells for efficacious intratumoral adoptive immunotherapy

Interleukin-12 (IL-12) gene transfer enhances the therapeutic potency of adoptive T cell therapies. We previously reported that transient engineering of tumor-specific CD8 T cells with IL-12 mRNA enhanced their systemic therapeutic efficacy when delivered intratumorally. Here, we mix T cells engineered with mRNAs to express either single-chain IL-12 (scIL-12) or an IL-18 decoy-resistant variant (DRIL18) that is not functionally hampered by IL-18 binding protein (IL-18BP). These mRNA-engineered T cell mixtures are repeatedly injected into mouse tumors. Pmel-1 T cell receptor (TCR)-transgenic T cells electroporated with scIL-12 or DRIL18 mRNAs exert powerful therapeutic effects in local and distant melanoma lesions. These effects are associated with T cell metabolic fitness, enhanced miR-155 control on immunosuppressive target genes, enhanced expression of various cytokines, and changes in the glycosylation profile of surface proteins, enabling adhesiveness to E-selectin. Efficacy of this intratumoral immunotherapeutic strategy is recapitulated in cultures of tumor-infiltrating lymphocytes (TILs) and chimeric antigen receptor (CAR) T cells on IL-12 and DRIL18 mRNA electroporation.

The effect of operator's experience on mechanical thrombectomy outcomes: A systematic review

BACKGROUND

Mechanical thrombectomy (MT) has become the standard of care for stroke patients. The majority of the clinical trials and publications analyzing the outcomes related to the procedures report interventional performance by experienced practitioners. However, few of them individualize their preliminary metrics according to the operator's experience.

OBJECTIVE

To summarize the literature and report safety and efficacy outcomes following MT procedures and correlate them with the operator's experience. Primary outcomes were successful recanalization, defined as modified thrombolysis in cerebral infarction greater or equal to 2b or 3, duration of the procedure measured in minutes, and serious adverse event.

METHODS

This systematic review was performed according to the PRISMA guidelines. The PubMed, Embase, and Cochrane databases were utilized.

RESULTS

There were six studies comprising 9348 patients (mean age 69.8 years; 51.2% males), and 9361 MT procedures were included. Each publication used for this review used a different experience definition to report their data. Higher interventionists' experience demonstrated a positive relationship with the possibility of successful recanalization and an inverse relationship with the duration needed for the operation in almost all of the included studies. As for the complications, none of the authors reported a statistically significant risk reduction of an adverse event, except Olthuis et al. correlating increasing training with lower odds of stroke progression.

CONCLUSIONS

A higher experience level is associated with better recanalization rates and shorter procedural duration in MT operations. Further studies are warranted to define the minimum required level of experience for operational autonomy.

Radiation Therapy Modulates Tumor Physical Characteristics to Reduce Intratumoral Pressure and Enhance Intratumoral Drug Delivery and Retention

Purpose

High intratumoral pressure, caused by tumor cell-to-cell interactions, interstitial fluid pressure, and surrounding stromal composition, plays a substantial role in resistance to intratumoral drug delivery and distribution. Radiation therapy (XRT) is commonly administered in conjunction with different intratumoral drugs, but assessing how radiation can reduce pressure locally and help intratumoral drug administration and retention is important.

Methods and Materials

344SQ-parental or 344SQ-anti-programmed cell death protein 1-resistant lung adenocarcinoma cells were established in 129Sv/Ev mice, and irradiated with either 1 Gy × 2, 5 Gy × 3, 8 Gy × 3, 12 Gy × 3, or 20 Gy × 1. Intratumoral pressure was measured every 3 to 4 days after XRT. Contrast dye was injected into the tumors 3- and 6-days after XRT, and imaged to measure drug retention.

Results

In the 344SQ-parental model, low-dose radiation (1 Gy × 2) created an early window of reduced intratumoral pressure 1 to 3 days after XRT compared with untreated control. High-dose stereotactic radiation (12 Gy × 3) reduced intratumoral pressure 3 to 12 days after XRT, and 20 Gy × 1 showed a delayed pressure reduction on day 12. Intermediate doses of radiation did not significantly affect intratumoral pressure. In the more aggressive 344SQ-anti-programmed cell death protein 1-resistant model, low-dose radiation reduced pressure 1 to 5 days after XRT, and 12 Gy × 3 reduced pressure 1 to 3 days after XRT. Moreover, both 1 Gy × 2 and 12 Gy × 3 significantly improved drug retention 3 days after XRT; however, there was no significance detected 6 days after XRT. Lastly, a histopathologic evaluation showed that 1 Gy × 2 reduced collagen deposition within the tumor, and 12 Gy × 3 led to more necrotic core and higher extracellular matrix formation in the tumor periphery.

Conclusions

Optimized low-dose XRT, as well as higher stereotactic XRT regimen led to a reduction in intratumoral pressure and increased drug retention. The findings from this work can be readily translated into the clinic to enhance intratumoral injections of various anticancer agents.

Tumor response assessment on imaging following immunotherapy

In recent years, various systemic immunotherapies have been developed for cancer treatment, such as monoclonal antibodies (mABs) directed against immune checkpoints (immune checkpoint inhibitors, ICIs), oncolytic viruses, cytokines, cancer vaccines, and adoptive cell transfer. While being estimated to be eligible in 38.5% of patients with metastatic solid or hematological tumors, ICIs, in particular, demonstrate durable disease control across many oncologic diseases (e.g., in melanoma, lung, bladder, renal, head, and neck cancers) and overall survival benefits. Due to their unique mechanisms of action based on T-cell activation, response to immunotherapies is characterized by different patterns, such as progression prior to treatment response (pseudoprogression), hyperprogression, and dissociated responses following treatment. Because these features are not encountered in the Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1), which is the standard for response assessment in oncology, new criteria were defined for immunotherapies. The most important changes in these new morphologic criteria are, firstly, the requirement for confirmatory imaging examinations in case of progression, and secondly, the appearance of new lesions is not necessarily considered a progressive disease. Until today, five morphologic (immune-related response criteria (irRC), immune-related RECIST (irRECIST), immune RECIST (iRECIST), immune-modified RECIST (imRECIST), and intra-tumoral RECIST (itRECIST)) criteria have been developed to accurately assess changes in target lesion sizes, taking into account the specific response patterns after immunotherapy. In addition to morphologic response criteria, 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG-PET/CT) is a promising option for metabolic response assessment and four metabolic criteria are used (PET/CT Criteria for Early Prediction of Response to Immune Checkpoint Inhibitor Therapy (PECRIT), PET Response Evaluation Criteria for Immunotherapy (PERCIMT), immunotherapy-modified PET Response Criteria in Solid Tumors (imPERCIST5), and immune PERCIST (iPERCIST)). Besides, there is evidence that parameters on 18F-FDG-PET/CT, such as the standardized uptake value (SUV)max and several radiotracers, e.g., directed against PD-L1, may be potential imaging biomarkers of response. Moreover, the emerge of human intratumoral immunotherapy (HIT-IT), characterized by the direct injection of immunostimulatory agents into a tumor lesion, has given new importance to imaging assessment. This article reviews the specific imaging patterns of tumor response and progression and available imaging response criteria following immunotherapy.

Image-guided intratumoral immunotherapy: Developing a clinically practical technology

Immunotherapy has revolutionized the contemporary oncology landscape, with durable responses possible across a range of cancer types. However, the majority of cancer patients do not respond to immunotherapy due to numerous immunosuppressive barriers. Efforts to overcome these barriers and increase systemic immunotherapy efficacy have sparked interest in the local intratumoral delivery of immune stimulants to activate the local immune response and subsequently drive systemic tumor immunity. While clinical evaluation of many therapeutic candidates is ongoing, development is hindered by a lack of imaging confirmation of local delivery, insufficient intratumoral drug distribution, and a need for repeated injections. The use of polymeric drug delivery systems, which have been widely used as platforms for both image guidance and controlled drug release, holds promise for delivery of intratumoral immunoadjuvants and the development of an in situ cancer vaccine for patients with metastatic cancer. In this review, we explore the current state of the field for intratumoral delivery and methods for optimizing controlled drug release, as well as practical considerations for drug delivery design to be optimized for clinical image guided delivery particularly by CT and ultrasound.

Thermal ablation of the most challenging cases of liver metastases

Patient selection for image-guided thermal ablation of liver metastases has to be taken in a multidisciplinary tumor board given the extreme complexity of cancer metastatic disease, and the numerous treatment options offered to oligometastatic patient today.The role of image-guided thermal ablation increases over years in the treatment of liver metastases. In order to fulfill the expected outcomes which are to have a local control rate equivalent to surgery, interventional oncologist have to take every measure that will help when treating most challenging metastases including image guidance, anesthesia, respiration monitoring, ablation technique, confirmation software that can favor positive outcomes, and in some way to render challenging metastases easy to treat.

Oncopharmacology in Interventional Radiology

The broad scope of malignancies treated in interventional oncology is mirrored by the breadth of oncotherapeutics, drugs used to treat cancer. Many of these treatments are administered endovascularly, though a group of therapies can be delivered percutaneously. Perhaps the best taxonomy of oncotherapeutics is based on their biological inactivity or activity and the mechanism by which they interact with treated and targeted tissues. As the fields of interventional oncology and oncotherapeutics continue to grow and expand, this framework may provide a more organized approach in helping distinguish and select the best therapy for patients.

Techniques for Profiling the Cellular Immune Response and Their Implications for Interventional Oncology

In recent years there has been increased interest in using the immune contexture of the primary tumors to predict the patient's prognosis. The tumor microenvironment of patients with cancers consists of different types of lymphocytes, tumor-infiltrating leukocytes, dendritic cells, and others. Different technologies can be used for the evaluation of the tumor microenvironment, all of which require a tissue or cell sample. Image-guided tissue sampling is a cornerstone in the diagnosis, stratification, and longitudinal evaluation of therapeutic efficacy for cancer patients receiving immunotherapies. Therefore, interventional radiologists (IRs) play an essential role in the evaluation of patients treated with systemically administered immunotherapies. This review provides a detailed description of different technologies used for immune assessment and analysis of the data collected from the use of these technologies. The detailed approach provided herein is intended to provide the reader with the knowledge necessary to not only interpret studies containing such data but also design and apply these tools for clinical practice and future research studies.

Feasibility, safety and efficacy of human intra-tumoral immuno-therapy. Gustave Roussy's initial experience with its first 100 patients

PURPOSE

Many intratumoural (IT) immunotherapies are currently developed in the clinic with the aim of overcoming primary and secondary resistance and/or to limit on-target/off-tumour toxicities of immune checkpoint targeted therapies. This study aimed to describe the feasibility, safety and efficacy of IT immunotherapy treatments.

DESIGN

This retrospective single-centre study included the first 100 consecutive patients enrolled in Gustave Roussy's Human IntraTumoral-ImmunoTherapy (HIT-IT) program. Patient characteristics, target description, image guidance, safety and response according to iRECIST (Response Evaluation Criteria in Solid Tumours for immunotherapy trials) were recorded. Predictive factors of complications and responses were analysed. Survival was also reported.

RESULTS

From 09/2015 to 05/2020, 100 patients had 115 tumours injected during 423 treatment cycles. Most frequent primary tumour arose from the skin (n = 49), digestive track (n = 4) or head and neck (n = 8). Injected tumours' mean diameter was 37 ± 23 mm, and a median number of 4 IT injections per patient (interquartile range:3-5) were performed. Targeted tumours for IT injections were superficial lymph nodes (36.5%), subcutaneous lesions (25.2%), liver tumours (20.9%) and others (17.4% including tumour sites such as deep lymph nodes or lung). Most patients (72%) received systemic immunotherapy in combination with HIT-IT. Procedure- and drug-related adverse events (AEs) occurred in 11.3% and 33.3% of the treatment cycles, respectively. Only 3 procedure-related AEs were grade-3 (0.7%); and no grade-4 or 5 occurred. Among all cycles, 7 grade-3 and 1 grade-5 drug-related AEs were reported. Complete and partial responses were achieved for 5% and 18% of patients, respectively, while stable disease was the best response for 11%. Patients receiving HIT-IT as a 1st-line treatment (24%), or not previously pre-treated with immunotherapy (53%) responded better, p = 0.001 and p = 0.004, respectively. From 1st cycle of IT, 12-month overall progression-free survival and overall survival were 21% (14-31%) and 57% (47-68%), respectively.

CONCLUSIONS

This retrospective study, conducted on patients with cancer and treated within clinical trials at Gustave Roussy, demonstrates the feasibility and safety of the IT immunotherapy strategy.

Intratumorally anchored cytokine therapy

INTRODUCTION

On-target, off-tumor toxicity severely limits systemic dosing of cytokines and agonist antibodies for cancer. Intratumoral administration is increasingly being explored to mitigate this problem. Full exploitation of this mode of administration must include a mechanism for sustained retention of the drug; otherwise, rapid diffusion out of the tumor eliminates any advantage.

AREAS COVERED

We focus here on strategies for anchoring immune agonists in accessible formats. Such anchoring may utilize extracellular matrix components, cell surface receptor targets, or exogenously administered particulate materials. Promising alternative strategies not reviewed here include slow release from the interior of a material depot, expression following local transfection, and conditional proteolytic activation of masked molecules.

EXPERT OPINION

An effective mechanism for tissue retention is a critical component of intratumorally anchored cytokine therapy, as leakage leads to decreased tumor drug exposure and increased systemic toxicity. Matching variable drug release kinetics with receptor-mediated cellular uptake is an intrinsic requirement for the alternative strategies mentioned above. Bioavailability of an anchored form of the administered drug is key to obviating this balancing act.

Image-guided interventional radiological delivery of chimeric antigen receptor (CAR) T cells for pleural malignancies in a phase I/II clinical trial

OBJECTIVES

We describe techniques and results of image-guided delivery of mesothelin-targeted chimeric antigen receptor (CAR) T cells in patients with pleural malignancies in a phase I/II trial (ClinicalTrials.gov: NCT02414269).

MATERIALS AND METHODS

Patients without a pleural catheter or who lack effusion for insertion of a catheter (31 of 41) were administered intrapleural CAR T cells by interventional radiologists under image guidance by computed tomography or ultrasound. CAR T cells were administered through a needle in an accessible pleural loculation (intracavitary) or following an induced loculated artificial pneumothorax. In patients where intracavitary infusion was not feasible, CAR T cells were injected via percutaneous approach either surrounding and/or in the pleural nodule/thickening (intratumoral). Pre- and post-procedural clinical, laboratory, and imaging findings were assessed.

RESULTS

CAR T cells were administered intrapleurally in 31 patients (33 procedures, 2 patients were administered a second dose) with successful delivery of planned dose (10-186 mL); 14/33 (42%) intracavitary and 19/33 (58%) intratumoral. All procedures were completed within 2 h of T-cell thawing. There were no procedure-related adverse events greater than grade 1 (1 in 3 patients had prior ipsilateral pleural fusion procedures). The most common imaging finding was ground glass opacities with interlobular septal thickening and/or consolidation, observed in 12/33 (36%) procedures. There was no difference in the incidence of fever, CRP, IL-6, and peak vector copy number in the peripheral blood between infusion methods.

CONCLUSION

Image-guided intrapleural delivery of CAR T cells using intracavitary or intratumoral routes is feasible, repeatable and safe across anatomically variable pleural cancers.

Intratumoral co-injection of the poly I:C-derivative BO-112 and a STING agonist synergize to achieve local and distant anti-tumor efficacy

BACKGROUND

BO-112 is a nanoplexed form of polyinosinic:polycytidylic acid that acting on toll-like receptor 3 (TLR3), melanoma differentiation-associated protein 5 (MDA5) and protein kinase RNA-activated (PKR) elicits rejection of directly injected transplanted tumors, but has only modest efficacy against distant untreated tumors. Its clinical activity has also been documented in early phase clinical trials. The 5,6-dimethylxanthenone-4-acetic acid (DMXAA) stimulator of interferon genes (STING) agonist shows a comparable pattern of efficacy when used via intratumoral injections.

METHODS

Mice subcutaneously engrafted with bilateral MC38 and B16.OVA-derived tumors were treated with proinflammatory immunotherapy agents known to be active when intratumorally delivered. The combination of BO-112 and DMXAA was chosen given its excellent efficacy and the requirements for antitumor effects were studied on selective depletion of immune cell types and in gene-modified mouse strains lacking basic leucine zipper ATF-like transcription factor 3 (BATF3), interferon-α/β receptor (IFNAR) or STING. Spatial requirements for the injections were studied in mice bearing three tumor lesions.

RESULTS

BO-112 and DMXAA when co-injected in one of the lesions of mice bearing concomitant bilateral tumors frequently achieved complete local and distant antitumor efficacy. Synergistic effects were contingent on CD8 T cell lymphocytes and dependent on conventional type 1 dendritic cells, responsiveness to type I interferon (IFN) and STING function in the tumor-bearing host. Efficacy was preserved even if BO-112 and DMXAA were injected in separate lesions in a manner able to control another untreated third-party tumor. Efficacy could be further enhanced on concurrent PD-1 blockade.

CONCLUSION

Clinically feasible co-injections of BO-112 and a STING agonist attain synergistic efficacy able to eradicate distant untreated tumor lesions.

Study on the Correlation Factors of Tumour Prognosis after Intravascular Interventional Therapy

Noninvasive or minimally invasive interventional surgery was selected, and the complications were less and had no significant impact on the quality of life of patients. Tumour patients are often accompanied by cerebrovascular diseases, metabolic diseases, and other basic diseases, which more or less adversely affect the surgical efficacy of tumour. In this paper, endovascular remobilization was used to treat tumour; the basic condition of patients before operation and the interventional operation plan were introduced. Through the analysis of clinical data and prognosis evaluation results of tumour patients receiving intravascular interventional therapy, the patients were divided into good prognosis group and poor prognosis group according to the modified Rankin scale score at discharge. The relationship between gender, age, history of hypertension, tumour width, tumour size, preoperative Hunt-Hess grade, interventional surgery method, and prognosis related to intravascular interventional therapy was explored. The results showed that intravascular interventional therapy for tumour patients can obtain a good prognosis, which provides a reference for the future preoperative assessment of treatment risk and possible prognosis and provides a theoretical basis for the formulation of treatment plan to improve prognosis.

Hyperthermia and Tumor Immunity

Thermal ablation is a cornerstone in the management of cancer patients. Typically, ablation procedures are performed for patients with a solitary or oligometastatic disease with the intention of eradicating all sites of the disease. Ablation has traditionally played a less prominent role for patients with a widely metastatic disease. For such patients, attempting to treat numerous sites of disease compounds potential risks without a clear clinical benefit and, as such, a compelling justification for performing an intervention that is unlikely to alter a patient's clinical trajectory is uncommon. However, the discovery of immune checkpoints and the development of immune checkpoint inhibitors have brought a new perspective to the relevance of local cancer therapies such as ablation for patients with a metastatic disease. It is becoming increasingly apparent that local cancer therapies can have systemic immune effects. Thus, in the new perspective of cancer care centered upon immunologic principles, there is a strong interest in exploring the utility of ablation for patients with a metastatic disease for its immunologic implications. In this review, we summarize the unmet clinical need for adjuvant interventions such as ablation to broaden the impact of systemic immunotherapies. We additionally highlight the extant preclinical and clinical data for the immunogenicity of common thermal ablation modalities.