Investigating the complex interplay between fibroblast activation protein α-positive cancer associated fibroblasts and the tumor microenvironment in the context of cancer immunotherapy.

Introduction: This study investigates the role of Fibroblast Activation Protein (FAP)-positive cancer-associated fibroblasts (FAP+CAF) in shaping the tumor immune microenvironment, focusing on its association with immune cell functionality and cytokine expression patterns. Methods: Utilizing immunohistochemistry, we observed elevated FAP+CAF density in metastatic versus primary renal cell carcinoma (RCC) tumors, with higher FAP+CAF correlating with increased T cell infiltration in RCC, a unique phenomenon illustrating the complex interplay between tumor progression, FAP+CAF density, and immune response. Results: Analysis of immune cell subsets in FAP+CAF-rich stromal areas further revealed significant correlations between FAP+ stroma and various T cell types, particularly in RCC and non-small cell lung cancer (NSCLC). This was complemented by transcriptomic analyses, expanding the range of stromal and immune cell subsets interrogated, as well as to additional tumor types. This enabled evaluating the association of these subsets with tumor infiltration, tumor vascularization and other components of the tumor microenvironment. Our comprehensive study also encompassed cytokine, angiogenesis, and inflammation gene signatures across different cancer types, revealing heterogeneous cellular composition, cytokine expressions and angiogenic profiles. Through cytokine pathway profiling, we explored the relationship between FAP+CAF density and immune cell states, uncovering potential immunosuppressive circuits that limit anti-tumor activity in tumor-resident immune cells. Conclusions: These findings underscore the complexity of tumor biology and the necessity for personalized therapeutic and patient enrichment approaches. The insights gathered from FAP+CAF prevalence, immune infiltration, and gene signatures provide valuable perspectives on tumor microenvironments, aiding in future research and clinical strategy development.

Case report: Fatal overwhelming post-splenectomy infection in a patient with metastatic angiosarcoma treated with immunotherapy.

A patient in his 40s with splenic angiosarcoma metastatic to the liver underwent splenectomy, chemotherapy, and partial hepatectomy before being treated on a clinical trial with CTLA4 and PD1 inhibitors. He had received pneumococcal and meningococcal vaccines post-splenectomy. On week 10, he developed grade 3 immune-related colitis, successfully treated with the anti-tumor necrosis factor-alpha inhibitor infliximab and steroids. After 4 cycles of treatment, scans showed partial response. He resumed anti-PD1 therapy, and 6 hours after the second dose of anti-PD1 he presented to the emergency room with hematemesis, hematochezia, hypotension, fever, and oxygen desaturation. Laboratory tests demonstrated acute renal failure and septicemia (Streptococcus pneumoniae). He died 12 hours after the anti-PD1 infusion from overwhelming post-splenectomy infection (OPSI). Autopsy demonstrated non-viable liver tumors among other findings. In conclusion, patients undergoing immunotherapy and with prior history of asplenia should be monitored closely for OPSI as they may be at increased risk.

ADGRE5-centered Tsurv model in T cells recognizes responders to neoadjuvant cancer immunotherapy.

Background: Neoadjuvant immunotherapy with anti-programmed death-1 (neo-antiPD1) has revolutionized perioperative methods for improvement of overall survival (OS), while approaches for major pathologic response patients' (MPR) recognition along with methods for overcoming non-MPR resistance are still in urgent need. Methods: We utilized and integrated publicly-available immune checkpoint inhibitors regimens (ICIs) single-cell (sc) data as the discovery datasets, and innovatively developed a cell-communication analysis pipeline, along with a VIPER-based-SCENIC process, to thoroughly dissect MPR-responding subsets. Besides, we further employed our own non-small cell lung cancer (NSCLC) ICIs cohort's sc data for validation in-silico. Afterward, we resorted to ICIs-resistant murine models developed by us with multimodal investigation, including bulk-RNA-sequencing, Chip-sequencing and high-dimensional cytometry by time of flight (CYTOF) to consolidate our findings in-vivo. To comprehensively explore mechanisms, we adopted 3D ex-vivo hydrogel models for analysis. Furthermore, we constructed an ADGRE5-centered Tsurv model from our discovery dataset by machine learning (ML) algorithms for a wide range of tumor types (NSCLC, melanoma, urothelial cancer, etc.) and verified it in peripheral blood mononuclear cells (PBMCs) sc datasets. Results: Through a meta-analysis of multimodal sequential sc sequencing data from pre-ICIs and post-ICIs, we identified an MPR-expanding T cells meta-cluster (MPR-E) in the tumor microenvironment (TME), characterized by a stem-like CD8+ T cluster (survT) with STAT5-ADGRE5 axis enhancement compared to non-MPR or pre-ICIs TME. Through multi-omics analysis of murine TME, we further confirmed the existence of survT with silenced function and immune checkpoints (ICs) in MPR-E. After verification of the STAT5-ADGRE5 axis of survT in independent ICIs cohorts, an ADGRE5-centered Tsurv model was then developed through ML for identification of MPR patients pre-ICIs and post-ICIs, both in TME and PBMCs, which was further verified in pan-cancer immunotherapy cohorts. Mechanistically, we unveiled ICIs stimulated ADGRE5 upregulation in a STAT5-IL32 dependent manner in a 3D ex-vivo system (3D-HYGTIC) developed by us previously, which marked Tsurv with better survival flexibility, enhanced stemness and potential cytotoxicity within TME. Conclusion: Our research provides insights into mechanisms underlying MPR in neo-antiPD1 and a well-performed model for the identification of non-MPR.

Application of toll-like receptors (TLRs) and their agonists in cancer vaccines and immunotherapy.

Toll-like receptors (TLRs) are pattern recognition receptors (PRRs) expressed in various immune cell types and perform multiple purposes and duties involved in the induction of innate and adaptive immunity. Their capability to propagate immunity makes them attractive targets for the expansion of numerous immunotherapeutic approaches targeting cancer. These immunotherapeutic strategies include using TLR ligands/agonists as monotherapy or combined therapeutic strategies. Several TLR agonists have demonstrated significant efficacy in advanced clinical trials. In recent years, multiple reports established the applicability of TLR agonists as adjuvants to chemotherapeutic drugs, radiation, and immunotherapies, including cancer vaccines. Cancer vaccines are a relatively novel approach in the field of cancer immunotherapy and are currently under extensive evaluation for treating different cancers. In the present review, we tried to deliver an inclusive discussion of the significant TLR agonists and discussed their application and challenges to their incorporation into cancer immunotherapy approaches, particularly highlighting the usage of TLR agonists as functional adjuvants to cancer vaccines. Finally, we present the translational potential of rWTC-MBTA vaccination [irradiated whole tumor cells (rWTC) pulsed with phagocytic agonists Mannan-BAM, TLR ligands, and anti-CD40 agonisticAntibody], an autologous cancer vaccine leveraging membrane-bound Mannan-BAM, and the immune-inducing prowess of TLR agonists as a probable immunotherapy in multiple cancer types.

Case Report: Overcoming challenges in pancreatic cancer with liver metastases: a personalized therapeutic odyssey of TACE, ablation, and immunotherapy.

Pancreatic cancer represents a malignant neoplasm originating from pancreatic cells. The optimal approach to cancer treatment remains uncertain, lacking a definitive consensus. Here, we present a compelling case of a 49-year-old female with pancreatic head cancer with liver metastases, as identified by CT and confirmed by biopsy. PET-CT indicated widespread metastatic involvement. TACE therapy with gemcitabine and cisplatin was initiated, yielding a stable disease response. The patient's high PD-L1 expression prompted TACE-PD-1 monoclonal antibody combination therapy. Subsequent treatments, including ablation, sustained PD-1 immunotherapy, and consolidation TACE, culminated in a complete response, as evidenced by imaging and tumor marker dynamics. Our case underscores the potential of multifaceted strategies in managing aggressive pancreatic cancer.

Bioorthogonal Guided Activation of cGAS-STING by AIE Photosensitizer Nanoparticles for Targeted Tumor Therapy and Imaging.

Photodynamic therapy (PDT) and photothermal therapy (PTT) leverage reactive oxygen species (ROS) and control local hyperthermia by photosensitizer to perturb intracellular redox equilibrium, inducing DNA damage in both mitochondria and nucleus, activating the cGAS-STING pathway, ultimately eliciting antitumor immune responses. However, current photosensitizers are encumbered by limitations such as suboptimal tumor targeting, aggregation-caused quenching (ACQ), and restricted excitation and emission wavelengths. Here, this work designs novel nanoparticles based on aggregation-induced emission (AIE) photosensitizer (BODTPE) for targeted tumor therapy and near-infrared II fluorescence imaging (NIR-II FLI) with enhanced PDT/PTT effects. BODTPE is employed as a monomer, dibenzocyclooctyne (DBCO)-PEG2k -amine serving as an end-capping polymer, to synthesize a BODTPE-containing polymer (DBD). Further, through self-assembly, DBD and mPEG-DSPE2k combined to form nanoparticles (NP-DBD). Notably, the DBCO on the surface of NP-DBD can react with azide groups on cancer cells pretreated with Ac4 ManNAz through a copper-free click reaction. This innovative formulation led to targeted accumulation of NP-DBD within tumor sites, a phenomenon convincingly demonstrated in murine tumor models subjected to N-azidoacetylmannosamine-tetraacylated (Ac4 ManNAz) pretreatment. Significantly, NP-DBD exhibits a multifaceted effect encompassing PDT/PTT/NIR-II FLI upon 808 nm laser irradiation, thereby better activating the cGAS-STING pathway, culminating in a compelling tumor inhibition effect augmented by robust immune modulation.

Insights in the host response towards biomaterial-based scaffolds for cancer therapy.

Immunotherapeutic strategies have shown promising results in the treatment of cancer. However, not all patients respond, and treatments can have severe side-effects. Adoptive cell therapy (ACT) has shown remarkable therapeutic efficacy across different leukaemia and lymphoma types. But the treatment of solid tumours remains a challenge due to limited persistence and tumour infiltration. We believe that biomaterial-based scaffolds are promising new tools and may address several of the challenges associated with cancer vaccination and ACT. In particular, biomaterial-based scaffold implants allow for controlled delivery of activating signals and/or functional T cells at specific sites. One of the main challenges for their application forms the host response against these scaffolds, which includes unwanted myeloid cell infiltration and the formation of a fibrotic capsule around the scaffold, thereby limiting cell traffic. In this review we provide an overview of several of the biomaterial-based scaffolds designed for cancer therapy to date. We will discuss the host responses observed and we will highlight design parameters that influence this response and their potential impact on therapeutic outcome.

Oncolytic Adenoviruses Armed with Co-Stimulatory Molecules for Cancer Treatment.

In clinical trials, adenovirus vectors (AdVs) are commonly used platforms for human gene delivery therapy. High genome capacity and flexibility in gene organization make HAdVs suitable for cloning. Recent advancements in molecular techniques have influenced the development of genetically engineered adenovirus vectors showing therapeutic potential. Increased molecular understanding of the benefits and limitations of HAdVs in preclinical research and clinical studies is a crucial point in the engineering of refined oncolytic vectors. This review presents HAdV species (A-G) used in oncotherapy. We describe the adenovirus genome organizations and modifications, the possibilities oncolytic viruses offer, and their current limitations. Ongoing and ended clinical trials based on oncolytic adenoviruses are presented. This review provides a broad overview of the current knowledge of oncolytic therapy. HAdV-based strategies targeting tumors by employing variable immune modifiers or delivering immune stimulatory factors are of great promise in the field of immune oncologyy This approach can change the face of the fight against cancer, supplying the medical tools to defeat tumors more selectively and safely.

Exosome Mediated Cancer Therapeutic Approach:Present Status and Future Prospectives.

The unique extracellular vesicles (EVs) or exosomes formed by the sequential invagination of the plasma membrane are diverse and encompass important constituents with biological functions. Speculations on its cell independent biological functions are significant and pose them as vital biomarkers and as drug delivery vehicles especially in cancer. EVs possess theragnostic values and are known to elicit specific immune response. Exosomes can also serve as potential nanocarriers for delivering miRNA, siRNA, anti-cancer drugs and membrane-associated proteins. Exosomes play a crucial role in regulating tumour progression, metastasis, and angiogenesis. This review thus portrays the multiple facets of exosomes, in concert with the source for exosomes production and further on its regulation and intercellular communication. The review also explores the recent advances, present status and the future prospective in the application of exosomes in cancer therapeutics and cancer diagnostics.

Using natural killer cell-derived exosomes as a cell-free therapy for leukemia.

Natural killer (NK) cells are components of the innate immune system which play a pivotal role in cancer cell surveillance. Despite promising results in clinical trials, the use of NK-based therapies is limited due to unsatisfactory efficiencies and safety issues. In recent years, exosomes have emerged as a powerful, natural therapeutic tool. Since exosomes are known to carry cargos that reflect the cellular makeup of their cell of origin, we were prompted to test whether NK-derived exosomes (NKexo) maintain the anti-leukemia capacity of NK-cells. We found NK92MI-cells to secrete large amounts of 100-200 nm cap-shaped particles expressing exosomal and NK biomarkers (CD63, CD81, CD56). We demonstrated that NKexo exert a potent, selective, anti-leukemia effect on all leukemia cell-lines tested. Furthermore, NKexo eliminated leukemia cells isolated from patients with acute and chronic leukemia and inhibited hematopoietic colony growth. While leukemia cells were targeted and severely affected by NKexo, healthy B-cells remained unaffected, indicating a selective effect. This selectivity was further confirmed by demonstrating that NKexo were specifically taken up by leukemic cells but not by healthy B-cells. Our in vivo data support our in vitro and ex vivo findings and demonstrate improved human-CD45+ leukemia blast counts and overall survival in NKexo treated humanized acute myeloid leukemia (HL-60) xenograft mice thus supporting the assumption that NKexo possess an anti-leukemia effect. Pending further analyses, our findings provide the pre-clinical evidence needed to test the NKexo approach in future pre-clinical and clinical studies to ultimately develop an acellular "off-the-shelf" product to treat leukemia.

Autophagy: Dual roles and perspective for clinical treatment of colorectal cancer.

Colorectal cancer (CRC) raises concerns to people because of its high recurrence and metastasis rate, diagnosis challenges, and poor prognosis. Various studies have shown the association of altered autophagy with tumorigenesis, tumor-stroma interactions, and resistance to cancer therapy in CRC. Autophagy is a highly conserved cytosolic catabolic process in eukaryotes that plays distinct roles in CRC occurrence and progression. In early tumorigenesis, autophagy may inhibit tumor growth through diverse mechanisms, whereas it exhibits a tumor promoting function in CRC progression. This different functions of autophagy in CRC occurrence and progression make developing therapies targeting autophagy complicated. In this review, we discuss the classification and process of autophagy as well as its dual roles in CRC, functions in the tumor microenvironment, cross-talk with apoptosis, and potential usefulness as a CRC therapeutic target.

Pathologic assessment of esophageal squamous cell carcinoma after neoadjuvant immunotherapy / 中华消化外科杂志

For locally advanced esophageal squamous cell carcinoma (ESCC), neoadjuvant therapy combined with surgery has become the standard treatment schedule. The application of immunotherapy, represented by programmed death-1 and programmed death-ligand 1 inhibitors, has injected new vitality into neoadjuvant therapy for ESCC. At present, a large number of clinical trials are being carried out and explored, which brings new challenges to the diagnosis of clinical pathologists. Combined with the latest researches at home and abroad and clinical diagnosis problems, the authors summarize the relevant problems and progress of pathological evaluation before and after neoadjuvant immunotherapy from the perspective of pathology, in order to improve the level of clinical pathological diagnosis and provide reference for further optimizing the comprehensive treat-ment strategy.

Telomere-related gene risk model for prognosis and drug treatment efficiency prediction in kidney cancer.

Kidney cancer is one of the most common urological cancers worldwide, and kidney renal clear cell cancer (KIRC) is the major histologic subtype. Our previous study found that von-Hippel Lindau (VHL) gene mutation, the dominant reason for sporadic KIRC and hereditary kidney cancer-VHL syndrome, could affect VHL disease-related cancers development by inducing telomere shortening. However, the prognosis role of telomere-related genes in kidney cancer has not been well discussed. In this study, we obtained the telomere-related genes (TRGs) from TelNet. We obtained the clinical information and TRGs expression status of kidney cancer patients in The Cancer Genome Atlas (TCGA) database, The International Cancer Genome Consortium (ICGC) database, and the Clinical Proteomic Tumor Analysis Consortium (CPTAC) database. Totally 353 TRGs were differential between tumor and normal tissues in the TCGA-KIRC dataset. The total TCGA cohort was divided into discovery and validation TCGA cohorts and then using univariate cox regression, lasso regression, and multivariate cox regression method to conduct data analysis sequentially, ten TRGs (ISG15, RFC2, TRIM15, NEK6, PRKCQ, ATP1A1, ELOVL3, TUBB2B, PLCL1, NR1H3) risk model had been constructed finally. The kidney patients in the high TRGs risk group represented a worse outcome in the discovery TCGA cohort (p<0.001), and the result was validated by these four cohorts (validation TCGA cohort, total TCGA cohort, ICGC cohort, and CPTAC cohort). In addition, the TRGs risk score is an independent risk factor for kidney cancer in all these five cohorts. And the high TRGs risk group correlated with worse immune subtypes and higher tumor mutation burden in cancer tissues. In addition, the high TRGs risk group might benefit from receiving immune checkpoint inhibitors and targeted therapy agents. Moreover, the proteins NEK6, RF2, and ISG15 were upregulated in tumors both at the RNA and protein levels, while PLCL1 and PRKCQ were downregulated. The other five genes may display the contrary expression status at the RNA and protein levels. In conclusion, we have constructed a telomere-related genes risk model for predicting the outcomes of kidney cancer patients, and the model may be helpful in selecting treatment agents for kidney cancer patients.

Prognostic and immune-related value of complement C1Q (C1QA, C1QB, and C1QC) in skin cutaneous melanoma.

Background: Skin cutaneous melanoma (SKCM) is a common malignancy that is associated with increased morbidity and mortality. Complement C1Q is composed of C1QA, C1QB, and C1QC and is involved in the occurrence and development of many malignant tumours. However, the effect of C1QA, C1QB, and C1QC expression on tumour immunity and prognosis of cutaneous melanoma remains unclear. Methods: First, we analysed C1QA, C1QB, and C1QC expression levels and prognostic values using Gene Expression Profiling Interactive Analysis (GEPIA) and Tumour Immune Estimation Resource (TIMER) analysis, and further validation was performed using RT-qPCR, The Human Protein Atlas, The Cancer Genome Atlas (TCGA) dataset, and Gene Expression Omnibus dataset. We then performed univariate/multivariate Cox proportional hazard model, clinicopathological correlation, and receiver operating characteristic curve analysis using TCGA dataset and established a nomogram model. Differentially expressed genes associated with C1QA, C1QB, and C1QC in SKCM were identified and analysed using LinkedOmics, TIMER, the Search Tool for the Retrieval of Interacting Genes database, and Metascape and Cytoscape software platforms. We used TIMER, GEPIA, and single-sample gene set enrichment analysis (ssGSEA) to analyse the relationship between the three genes and the level of immune cell infiltration, biomarkers, and checkpoint expression in SKCM. Finally, GSEA was utilized to study the functional pathways of C1QA, C1QB, and C1QC enrichment in SKCM. Results: The overexpression of C1QA, C1QB, and C1QC provided significant value in the diagnosis of SKCM and has been associated with better overall survival (OS). Multivariate Cox regression analysis indicated that C1QA, C1QB, and C1QC are independent prognostic biomarkers for patients with SKCM. Immune cell infiltration, biomarkers, and checkpoints were positively correlated with the expression of C1QA, C1QB, and C1QC. Furthermore, the results of functional and pathway enrichment analysis showed that immune-related and apoptotic pathways were significantly enriched in the high-expression group of C1QA, C1QB, and C1QC. Conclusion: We found that C1QA, C1QB, and C1QC can be used as biomarkers for the diagnosis and prognosis of SKCM patients. The upregulated expression levels of these three complement components benefit patients from OS and may increase the effect of immunotherapy. This result may be due to the dual effects of anti-tumour immunity and apoptosis.

A Novel Affinity Engineered Anti-CD47 Antibody With Improved Therapeutic Index That Preserves Erythrocytes and Normal Immune Cells.

Therapeutic blockade of the CD47/SIRPα axis by small molecules or monoclonal antibodies (mAbs) is a proven strategy to enhance macrophages-mediated anti-tumor activity. However, this strategy has been hampered by elevated on-target toxicities and rapid clearance due to the extensive CD47 expression on normal cells ("antigen sink") such as red blood cells (RBCs). To address these hurdles, we report on the development of STI-6643, an affinity-engineered fully human anti-CD47 IgG4 antibody with negligible binding to normal cells. STI-6643 exhibited no hemagglutination activity on human RBCs at concentrations up to 300 µg/mL yet specifically blocked the CD47/SIPRα interaction. Of particular interest, STI-6643 preserved T cell functionality in vitro and showed significantly lower immune cell depletion in vivo in contrast to three previously published competitor reference anti-CD47 clones Hu5F9, AO-176 and 13H3. In cynomolgus monkeys, STI-6643 was well-tolerated at the highest dose tested (300 mg/kg/week) and provided favorable clinical safety margins. Finally, STI-6643 displayed comparable anti-tumor activity to the high-affinity reference clone Hu5F9 in a RAJI-Fluc xenograft tumor model as monotherapy or in combination with anti-CD20 (rituximab) or anti-CD38 (daratumumab) mAbs. These data suggest that STI-6643 possesses the characteristics of an effective therapeutic candidate given its potent anti-tumor activity and low toxicity profile.

Emerging concepts in designing next-generation multifunctional nanomedicine for cancer treatment.

Nanotherapy has emerged as an improved anticancer therapeutic strategy to circumvent the harmful side effects of chemotherapy. It has been proven to be beneficial to offer multiple advantages, including their capacity to carry different therapeutic agents, longer circulation time and increased therapeutic index with reduced toxicity. Over time, nanotherapy evolved in terms of their designing strategies like geometry, size, composition or chemistry to circumvent the biological barriers. Multifunctional nanoscale materials are widely used as molecular transporter for delivering therapeutics and imaging agents. Nanomedicine involving multi-component chemotherapeutic drug-based combination therapy has been found to be an improved promising approach to increase the efficacy of cancer treatment. Next-generation nanomedicine has also utilized and combined immunotherapy to increase its therapeutic efficacy. It helps in targeting tumor immune response sparing the healthy systemic immune function. In this review, we have summarized the progress of nanotechnology in terms of nanoparticle designing and targeting cancer. We have also discussed its further applications in combination therapy and cancer immunotherapy. Integrating patient-specific proteomics and biomarker based information and harnessing clinically safe nanotechnology, the development of precision nanomedicine could revolutionize the effective cancer therapy.

A NK Cell Odyssey: From Bench to Therapeutics Against Hematological Malignancies.

In 1975 two independent groups noticed the presence of immune cells with a unique ability to recognize and eliminate transformed hematopoietic cells without any prior sensitization or expansion of specific clones. Since then, NK cells have been the axis of thousands of studies that have resulted until June 2021, in more than 70 000 publications indexed in PubMed. As result of this work, which include approaches in vitro, in vivo, and in natura, it has been possible to appreciate the role played by the NK cells, not only as effectors against specific pathogens, but also as regulators of the immune response. Recent advances have revealed previous unidentified attributes of NK cells including the ability to adapt to new conditions under the context of chronic infections, or their ability to develop some memory-like characteristics. In this review, we will discuss significant findings that have rule our understanding of the NK cell biology, the developing of these findings into new concepts in immunology, and how these conceptual platforms are being used in the design of strategies for cancer immunotherapy.

3D imaging for driving cancer discovery.

Our understanding of the cellular composition and architecture of cancer has primarily advanced using 2D models and thin slice samples. This has granted spatial information on fundamental cancer biology and treatment response. However, tissues contain a variety of interconnected cells with different functional states and shapes, and this complex organization is impossible to capture in a single plane. Furthermore, tumours have been shown to be highly heterogenous, requiring large-scale spatial analysis to reliably profile their cellular and structural composition. Volumetric imaging permits the visualization of intact biological samples, thereby revealing the spatio-phenotypic and dynamic traits of cancer. This review focuses on new insights into cancer biology uniquely brought to light by 3D imaging and concomitant progress in cancer modelling and quantitative analysis. 3D imaging has the potential to generate broad knowledge advance from major mechanisms of tumour progression to new strategies for cancer treatment and patient diagnosis. We discuss the expected future contributions of the newest imaging trends towards these goals and the challenges faced for reaching their full application in cancer research.

Isolated limb perfusion for locally advanced melanoma in the immunotherapy era.

BACKGROUND: Prior to the advent of effective systemic therapy for melanoma, isolated limb perfusion (ILP) was the most effective local treatment for advanced in-transit melanoma (ITM). However, many patients who are now treated by ILP will have received prior immunotherapy. We sought to compare response rates to ILP in patients who had previously received immunotherapy compared to immunotherapy naive patients. MATERIALS AND METHODS: All patients who underwent ILP for ITM between January 2015 and July 2020 for melanoma were identified retrospectively from two tertiary institutions. Surgical morbidity and oncologic outcomes were compared between immunotherapy naive and immunotherapy pre-treated patients. RESULTS: 97 perfusions were performed for melanoma. Of those, 18 patients had undergone prior immunotherapy. There were no differences in clinicopathological characteristics or perioperative outcomes between cohorts. Surgical morbidity and local toxicity were similar between both cohorts. Patients who underwent immunotherapy prior to ILP had significantly decreased complete response (CR) rates compared with immunotherapy-naïve (6% vs 47%, p = 0.0018) and a significantly decreased overall survival (OS) and distant progression free survival (DPFS) (p = 0.0031 and p = 0.0006 respectively). There was no difference in overall response (OR), partial response (PR), stable disease (SD), progressive disease (PD) and local progression free survival (LPFS) between cohorts. CONCLUSION: Oncological outcomes and complete response rates are worse in patients who have received immunotherapy prior to ILP compared with immunotherapy naïve patients. Despite this, ILP is still a valuable second line treatment for local control in patients who have multiple, bulky and/or recurrent ITM post immunotherapy.