Intralesional treatment of metastatic melanoma: a review of therapeutic options

Analyzing the mechanism by which oyster peptides target IL-2 in melanoma cell apoptosis based on RNA-seq and m6A-seq

Melanoma is a kind of skin cancer with high malignancy and strong proliferation and invasion abilities. Chemotherapy drugs in the clinic have the disadvantages of high price and high toxicity. Peptides are natural active ingredients that have many functions and are safe and effective. Previous studies have shown that oysters are rich in protein and have antitumor effects. In this study, a high-throughput strategy combined with MALDI TOF/TOF-MS and molecular docking was developed to screen peptides with antitumor functions from oyster hydrolysate. Three dominant peptides were predicted to have similar functions to IL-2 via molecular docking. Then, the activity of the peptides was confirmed in B16 cells, and we found that the three peptides increased the apoptosis of B16 cells. Furthermore, via RNA-seq and m6A-seq of B16 cells treated with the peptides, we found that ILADSAPR downregulates the expression of Pcna, Tlr4, and Ncbp2 and upregulates the expression of Bax, Bad, Pak4, Rasa2, Cct6, and Gbp2. ILADSAPR inhibited B16 cell proliferation and promoted cell apoptosis by regulating the expression of these genes. In addition, the result of metabolic pathway analysis also proved this point. This study provides a preliminary reference for antitumor research on oyster peptides.

Oncolytic virus: A catalyst for the treatment of gastric cancer

Gastric cancer (GC) is a leading contributor to global cancer incidence and mortality. According to the GLOBOCAN 2020 estimates of incidence and mortality for 36 cancers in 185 countries produced by the International Agency for Research on Cancer (IARC), GC ranks fifth and fourth, respectively, and seriously threatens the survival and health of people all over the world. Therefore, how to effectively treat GC has become an urgent problem for medical personnel and scientific workers at this stage. Due to the unobvious early symptoms and the influence of some adverse factors such as tumor heterogeneity and low immunogenicity, patients with advanced gastric cancer (AGC) cannot benefit significantly from treatments such as radical surgical resection, radiotherapy, chemotherapy, and targeted therapy. As an emerging cancer immunotherapy, oncolytic virotherapies (OVTs) can not only selectively lyse cancer cells, but also induce a systemic antitumor immune response. This unique ability to turn unresponsive 'cold' tumors into responsive 'hot' tumors gives them great potential in GC therapy. This review integrates most experimental studies and clinical trials of various oncolytic viruses (OVs) in the diagnosis and treatment of GC. It also exhaustively introduces the concrete mechanism of invading GC cells and the viral genome composition of adenovirus and herpes simplex virus type 1 (HSV-1). At the end of the article, some prospects are put forward to determine the developmental directions of OVTs for GC in the future.

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.

Development of Delivery Systems for Local Administration of Cytokines/Cytokine Gene-Directed Therapeutics: Modern Oncologic Implications

PURPOSE OF REVIEW

In this review, we discuss modern cytokine delivery systems in oncologic care, focusing on modalities being developed in the clinical trials or currently in use. These include pegylation, immune-cytokine drug conjugates, cytokine-expressing plasmid nanoparticles, nonviral cytokine nanoparticles, viral systems, and AcTakines.

RECENT FINDINGS

Cytokine therapy has the potential to contribute to cancer treatment options by modulating the immune system towards an improved antitumor response and has shown promise both independently and in combination with other immunotherapy agents. Despite promising preliminary studies, systemic toxicities and challenges with administration have limited the impact of unmodified cytokine therapy. In the last decade, novel delivery systems have been developed to address these challenges and facilitate cytokine-based oncologic treatments. Novel delivery systems provide potential solutions to decrease dose-limiting side effects, facilitate administration, and increase the therapeutic activity of cytokine treatments in oncology care. The expanding clinical and translational research in these systems provides an opportunity to augment the armamentarium of immune oncology and may represent the next frontier of cytokine-based immuno-oncology.

DNA binding and evaluation of anticancer activity in vitro and in vivo of iridium(III) polypyridyl complexes

In this report, we synthesized three new iridium(III) complexes: [Ir(piq)₂(apip)]PF₆ (Ir1, piq = 1-phenylisoquinoline, apip = 2-aminophenyl-1H-imidazo[4,5-f][1,10]phenanthroline), [Ir(piq)₂(maip)]PF₆ (Ir2, maip = 3-aminophenyl-1H-imidazo[4,5-f][1,10]phenanthroline) and [Ir(piq)₂(paip)]PF₆ (Ir3, paip = 4-aminophenyl-1H-imidazo[4,5-f][1,10]phenanthroline). The DNA binding was investigated. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method was used to detect the cytotoxic activity of Ir1, Ir2 and Ir3, the complexes show highly active against B16 cells with IC₅₀ values of 0.3 ± 0.2 μM, 3.7 ± 0.2 μM and 4.6 ± 1.1 μM, respectively. Subsequently, cellular uptake suggested that the cytotoxicity of the complexes is attributed to their differences in cellular uptake levels. In addition, complexes Ir1, Ir2 and Ir3 induce cell cycle arrest at the G0/G1 phase and regulate the cell cycle mediators such as cyclin D1, CDK6 (cyclin-dependent kinase 6), CDK4 and p21, leading to the inhibition of B16 cells proliferation. The autophagy was investigated by monodansylcadaverine (MDC) staining. The complexes can promote the change from LC3-I to LC3-II, up-regulate levels of Beclin-1 and down-regulate expression of p62. The complexes induced apoptosis by regulating the expression levels of related indicators such as PARP (poly ADP-ribose polymerase), PI3K (phosphoinositide-3 kinase), AKT (protein kinase B), Caspase, Bcl-2 (B-cell lymphoma-2), Bad (Bcl2 associated death promoter), Bax (Bcl2-associated X) and Cyto C (cytochrome C). Additionally, Ir1 exerted significant antitumor activity in the suppression of malignant melanoma proliferation in vivo. As indicated in the above results, these complexes were highly effective for malignant melanoma treatment through the intrinsic pathway and provided much insight into anticancer drugs for tumor therapy.

Dual Encapsulated Dacarbazine and Zinc Phthalocyanine Polymeric Nanoparticle for Photodynamic Therapy of Melanoma

PURPOSE

Melanoma is an invasive and very aggressive skin cancer due to its multi-drug resistance that results in poor patient survival. There is a need to test new treatment approaches to improve therapeutic efficacy and reduce side effects of conventional treatments.

METHODS

PLA/PVA nanoparticles carrying both Dacarbazine and zinc phthalocyanine was produced by double emulsion technique. The characterization was performed by dynamic light scattering and atomic force microscopy. In vitro photodynamic therapy test assay using MV3 melanoma cells as a model has been performed. In vitro cell viability (MTT) was performed to measure cell toxicity of of nanoparticles with and without drugs using human endothelial cells as a model. The in vivo assay (biodistribution/tissue deposition) has been performed using radiolabeled PLA/PVA NPs.

RESULTS

The nanoparticles produced showed a mean diameter of about 259 nm with a spherical shape. The in-vitro photodynamic therapy tests demonstrated that the combination is critical to enhance the therapeutic efficacy and it is dose dependent. The in vitro cell toxicity assay using endothelial cells demonstrated that the drug encapsulated into nanoparticles had no significant toxicity compared to control samples. In-vivo results demonstrated that the drug loading affects the biodistribution of the nanoparticle formulations (NPs). Low accumulation of the NPs into the stomach, heart, brain, and kidneys suggested that common side effects of Dacarbazine could be reduced.

CONCLUSION

This work reports a robust nanoparticle formulation with the objective to leveraging the synergistic effects of chemo and photodynamic therapies to potentially suppressing the drug resistance and reducing side effects associated with Dacarbazine. The data corroborates that the dual encapsulated NPs showed better in-vitro efficacy when compared with the both compounds alone. The results support the need to have a dual modality NP formulation for melanoma therapy by combining chemotherapy and photodynamic therapy.

Inference of molecular structure for characterization and improvement of clinical grade immunocytokines

The use of immunomodulatory agents for the treatment of cancer is gaining a growing biopharmaceutical interest. Antibody-cytokine fusion proteins, namely immunocytokines, represent a promising solution for the regulation of the immune system at the site of disease. The three-dimensional arrangement of these molecules can profoundly influence their biological activity and pharmacokinetic properties. Structural techniques might provide important insight in the 3D arrangement of immunocytokines. Here, we performed structure investigations on clinical grade fusion proteins L19-IL2, IL12-L19L19 and L19L19-IL2 to elucidate their quaternary organization. Crystallographic characterization of the common L19 antibody fragment at a resolution of 2.0-Å was combined with low-resolution studies of the full-length chimeric molecules using small-angle synchrotron X-ray scattering (SAXS) and negative stain electron microscopy. Characterization of the full-length quaternary structures of the immunocytokines in solution by SAXS consistently supported the diabody structure in the L19-IL2 immunocytokine and allowed generation of low-resolution models of the chimeric proteins L19L19-IL2 and IL12-L19L19. Comparison with 3D reconstructions obtained from negative-stain electron microscopy revealed marked flexibility associated to the linker regions connecting the cytokine and the antibody components of the chimeric proteins. Collectively, our results indicate that low-resolution molecular structure characterizations provide useful complementary insights for the quality control of immunocytokines, constituting a powerful tool to guide the design and the subsequent optimization steps towards clinical enhancement of these chimeric protein reagents.

Engineering IL-2 to Give New Life to T Cell Immunotherapy

Interleukin-2 (IL-2) is integral to immune system regulation. Its opposing immunostimulatory and immunosuppressive actions make it an attractive therapeutic target for cancer and autoimmune diseases. A challenge in developing IL-2-directed anticancer therapies has been how to stimulate effector T cells (Teffs) without inducing regulatory T cells (Tregs) in the tumor microenvironment; conversely, IL-2 therapy for autoimmune diseases requires Treg induction without further stimulation of Teffs. High-dose IL-2 is approved for melanoma and renal cell carcinoma, but its therapeutic value is limited by a need for frequent dosing at specialist centers, its short half-life, severe toxicity, and a lack of efficacy in most patients. Re-engineered IL-2 therapeutics are designed to have longer in vivo half-lives, target specific IL-2 receptor conformations to stimulate specific T cell subsets, or localize to target tissues to optimize efficacy and reduce toxicity. We discuss recent studies that elucidate the potential of newly engineered IL-2-based therapeutics for cancer and autoimmune diseases.

Targeting an engineered cytokine with interleukin-2 and interleukin-15 activity to the neovasculature of solid tumors

There is a growing interest in the antibody-based delivery of cytokines to the tumor environment as a means to boost the anti-cancer activity of tumor-resident T cells and NK cells. Here, we describe the expression and characterization of fusion proteins, featuring the L19 antibody (specific to the alternatively-spliced EDB domain of fibronectin) and an engineered cytokine with interleukin-2 and interleukin-15 properties. The cytokine moiety was fused either at the N-terminal or at the C-terminal extremity and both fusion proteins showed a selective tumor accumulation in a quantitative biodistribution experiment. The N-terminal fusion inhibited tumor growth in immunocompetent mice bearing F9 carcinomas or WEHI-164 sarcomas when used as single agent. The anticancer activity was compared to the one of the same cytokine payload used as recombinant protein or fused to an anti-hen egg lysozyme antibody, serving as negative control of irrelevant specificity in the mouse. These results indicate that the antibody-based delivery of engineered cytokines to the tumor neovasculature may mediate a potent anticancer activity.

Intratumoural immunotherapies for unresectable and metastatic melanoma: current status and future perspectives

The emergence of human intratumoural immunotherapy (HIT-IT) is a major step forward in the management of unresectable melanoma. The direct injection of treatments into melanoma lesions can cause cell lysis and induce a local immune response, and might be associated with a systemic immune response. Directly injecting immunotherapies into tumours achieves a high local concentration of immunostimulatory agent while minimising systemic exposure and, as such, HIT-IT agents are associated with lower toxicity than systemic immune checkpoint inhibitors (CPIs), enabling their potential use in combination with other therapies. Consequently, multiple HIT-IT agents, including oncolytic viruses, pattern-recognition receptor agonists, injected CPIs, cytokines and immune glycolipids, are under investigation. This review considers the current clinical development status of HIT-IT agents as monotherapy and in combination with systemic CPIs, and the practical aspects of administering and assessing the response to these agents. The future of HIT-IT probably lies in its use in combination with systemic CPIs; data from Phase 2 trials indicate a synergy between HIT-IT and CPIs. Data also suggest that the addition of HIT-IT to a CPI might generate responses in CPI-refractory tumours, thereby overcoming resistance and addressing a current unmet need in unresectable and metastatic melanoma for treatment options following progression after CPI treatment.

Anchoring of intratumorally administered cytokines to collagen safely potentiates systemic cancer immunotherapy

The clinical application of cytokine therapies for cancer treatment remains limited due to severe adverse reactions and insufficient therapeutic effects. Although cytokine localization by intratumoral administration could address both issues, the rapid escape of soluble cytokines from the tumor invariably subverts this effort. We find that intratumoral administration of a cytokine fused to the collagen-binding protein lumican prolongs local retention and markedly reduces systemic exposure. Combining local administration of lumican-cytokine fusions with systemic immunotherapies (tumor-targeting antibody, checkpoint blockade, cancer vaccine, or T cell therapy) improves efficacy without exacerbating toxicity in syngeneic tumor models and the Braf^V600E /Pten^fl/fl genetically engineered melanoma model. Curative abscopal effects on noncytokine-injected tumors were also observed as a result of a protective and systemic CD8⁺ T cell response primed by local therapy. Cytokine collagen-anchoring constitutes a facile, tumor-agnostic strategy to safely potentiate otherwise marginally effective systemic immunotherapies.

Neoadjuvant treatments in patients with high-risk resectable stage III/IV melanoma

Introduction: In recent years, the introduction of targeted therapy and immunotherapy into clinical practice has radically changed the management of advanced melanoma. More recently, these treatments also became the standard of care in the adjuvant setting. However, high-risk resectable stage III melanoma (i.e. with clinically detected regional lymph node involvement and/or satellites/in transit metastases) still has a high risk of relapse, even after adjuvant treatment, suggesting that the activity of immunotherapy and targeted therapy may play a relevant role in a neoadjuvant setting.Area covered: In this review, we discuss the results of the main clinical trials conducted in the neoadjuvant setting for patients with resectable stage III and stage IV melanoma, with a focus on the hot topics and a look at the future perspectives of the field.Expert opinion: The long-term effects of immunotherapy and the high response rate of targeted therapy provided the strong rationale to start neoadjuvant clinical trials for patients with resectable stage III and oligometastatic stage IV melanoma. Neoadjuvant therapy may play an important role not only for its possible impact on overall survival, but also as a predictive biological marker to allow for a more accurate personalization of adjuvant treatments.

International Multicenter Experience of Isolated Limb Infusion for In-Transit Melanoma Metastases in Octogenarian and Nonagenarian Patients

BACKGROUND

Isolated limb infusion (ILI) is used to treat in-transit melanoma metastases confined to an extremity. However, little is known about its safety and efficacy in octogenarians and nonagenarians (ON).

PATIENTS AND METHODS

ON patients (≥ 80 years) who underwent a first ILI for American Joint Committee on Cancer seventh edition stage IIIB/IIIC melanoma between 1992 and 2018 at nine international centers were included and compared with younger patients (< 80 years). A cytotoxic drug combination of melphalan and actinomycin-D was used.

RESULTS

Of the 687 patients undergoing a first ILI, 160 were ON patients (median age 84 years; range 80-100 years). Compared with the younger cohort (n = 527; median age 67 years; range 29-79 years), ON patients were more frequently female (70.0% vs. 56.9%; p = 0.003), had more stage IIIB disease (63.8 vs. 53.3%; p = 0.02), and underwent more upper limb ILIs (16.9% vs. 9.5%; p = 0.009). ON patients experienced similar Wieberdink limb toxicity grades III/IV (25.0% vs. 29.2%; p = 0.45). No toxicity-related limb amputations were performed. Overall response for ON patients was 67.3%, versus 64.6% for younger patients (p = 0.53). Median in-field progression-free survival was 9 months for both groups (p = 0.88). Median distant progression-free survival was 36 versus 23 months (p = 0.16), overall survival was 29 versus 40 months (p < 0.0001), and melanoma-specific survival was 46 versus 78 months (p = 0.0007) for ON patients compared with younger patients, respectively.

CONCLUSIONS

ILI in ON patients is safe and effective with similar response and regional control rates compared with younger patients. However, overall and melanoma-specific survival are shorter.

Local and Recurrent Regional Metastases of Melanoma

Up to 10% of patients with cutaneous melanoma will develop recurrent locoregional disease. While surgical resection remains the mainstay of treatment for isolated recurrences, locoregional melanoma can often present as bulky, unresectable disease and can pose a significant therapeutic challenge. This chapter focuses on the natural history of local and regionally recurrent metastases and the multiple treatment modalities which exist for advanced locoregional melanoma, including regional perfusion procedures such as hyperthermic isolated limb perfusion and isolated limb infusion, intralesional therapies, and neo-adjuvant systemic therapy strategies for borderline resectable regional disease. Hyperthermic limb perfusion (HILP) and isolated limb infusion (ILI) are generally well-tolerated and have shown overall response rates between 44% and 90%. Intralesional therapies also appear to be well-tolerated as adverse events are usually limited to the site of injection and minor transient flu-like symptoms. Systemic targeted therapies have shown to have response rates up to 85% when used as neoadjuvant therapy in patients with borderline resectable disease. While combination immunotherapy in the neoadjuvant setting has also shown promising results, this data has not yet matured.

First Eastern European experience of isolated limb infusion for in-transit metastatic melanoma confined to the limb: Is it still an effective treatment option in the modern era?

BACKGROUND

Isolated limb infusion (ILI) with cytotoxic agents is a simple and effective treatment option for patients with melanoma in-transit metastases (ITMs) confined to an extremity. Data for ILIs performed in Europe are sparse and to date no Eastern European ILI experience has been reported. The aim of the current study was to evaluate the efficacy of ILI in Estonia.

PATIENTS AND METHODS

Data for twenty-one patients were collected and analysed. All patients had melanoma ITMs and underwent an ILI between January 2012 and May 2018. The cytotoxic drug combination of melphalan and actinomycin-D was used. Drug circulation times were 20-30 min under mildly hyperthermic conditions (38-39 °C). Primary outcome measures were treatment response and overall survival.

RESULTS

Nineteen lower limb and two upper limb ILIs were performed. The female to male ratio was 18:3. The overall response rate (complete + partial response) was 76% (n = 16), with a complete response in 38% (n = 8). The overall long-term limb salvage rate was 90% (n = 19). During follow-up, eight patients (38%) died, two due to metastatic melanoma. Five-year overall survival was 57%.

CONCLUSION

This first Eastern European report of ILI for melanoma ITMs shows results comparable to those from other parts of the world. In this era of effective targeted and immune therapies, ILI remains a useful treatment option, with a high overall response rate and durable responses in patients with melanoma ITMs confined to a limb.

Topical and intralesional therapies for in-transitmelanoma

This report surveys the role of topical and intralesional agents in the management of in-transit melanoma. The extent and progression of in-transit disease is highly variable and many patients can have a protracted period of locoregional control. These agents are useful in the management of patients who have progressed beyond local surgical excision in whom more aggressive therapies, such as isolated limb infusion or use of talimogene laherparepvec, are not appropriate or have failed. In general, these agents are modestly effective and associated with frequent but only minor toxicity. As the mechanism of action of many of these agents includes initiation of a local immune response, combinations with immune checkpoint inhibitors are currently being explored.

Successful combination therapy of systemic checkpoint inhibitors and intralesional interleukin-2 in patients with metastatic melanoma with primary therapeutic resistance to checkpoint inhibitors alone

Systemic immunotherapy with PD-1 inhibitors is established in the treatment of metastatic melanoma. However, up to 60% of patients do not show long-term benefit from a PD-1 inhibitor monotherapy. Intralesional treatments with immunomodulatory agents such as the oncolytic herpes virus Talimogene Laherparepvec and interleukin-2 (IL-2) have been successfully used in patients with injectable metastases. Combination therapy of systemic and local immunotherapies is a promising treatment option in melanoma patients. We describe a case series of nine patients with metastatic melanoma and injectable lesions who developed progressive disease under a PD-1 inhibitor monotherapy. At the time of progressive disease, patients received intratumoral IL-2 treatment in addition to PD-1 inhibitor therapy. Three patients showed complete, three patients partial response and three patients progressive disease upon this combination therapy. IHC stainings were performed from metastases available at baseline (start of PD-1 inhibitor) and under combination therapy with IL-2. IHC results revealed a significant increase of CD4⁺ and CD8⁺ T cells and a higher PD-1 expression in the inflammatory infiltrate of the tumor microenvironment in metastases from patients with subsequent treatment response. All responding patients further showed a profound increase of the absolute eosinophil count (AEC) in the blood. Our case series supports the concept that patients with initial resistance to PD-1 inhibitor therapy and injectable lesions can profit from an additional intralesional IL-2 therapy which was well tolerated. Response to this therapy is accompanied by increase in AEC and a strong T cell-based inflammatory infiltrate.

Intratumoral administration of IL2- and TNF-based fusion proteins cures cancer without establishing protective immunity

AIM

The combination of tumor-targeting IL2- and TNF-based antibody-cytokine fusions has exhibited encouraging results in mouse and men. Here, we studied their combination to assess efficacy and mechanism of action in four different immunocompetent mouse models of cancer.

METHODS

Mice receiving a single intratumoral injection of F8-IL2, F8-TNF or the combination were investigated for tumor-infiltrating leukocytes and rechallenged when cured.

RESULTS

In three models, a proportion of treated animals could be cured, most probably by infiltrating NK and CD8⁺ T cells. Most of the cured mice did not acquire protective immunity when rechallenged with the same tumor cell line.

CONCLUSION

Immunocompetent mouse tumor models may not be adequate enough to predict the search for more efficacious therapy regimens.

Antibody-cytokine fusion proteins: A novel class of biopharmaceuticals for the therapy of cancer and of chronic inflammation

Antibody-cytokine fusion proteins represent a novel class of biopharmaceuticals, with the potential to increase the therapeutic index of cytokine 'payloads' and to promote leukocyte infiltration at the site of disease. In this review, we present a survey of immunocytokines that have been used in preclinical models of cancer and in clinical trials. In particular, we highlight how antibody format, choice of target antigen and cytokine engineering, as well as combination strategies, may have a profound impact on therapeutic performance. Moreover, by using anti-inflammatory cytokines, antibody fusion strategies can conveniently be employed for the treatment of auto-immune and chronic inflammatory conditions.

Antibody-cytokine fusion proteins: Biopharmaceuticals with immunomodulatory properties for cancer therapy

Cytokines have long been used for therapeutic applications in cancer patients. Substantial side effects and unfavorable pharmacokinetics limit their application and may prevent dose escalation to therapeutically active regimens. Antibody-cytokine fusion proteins (often referred to as immunocytokines) may help localize immunomodulatory cytokine payloads to the tumor, thereby activating anticancer immune responses. A variety of formats (e.g., intact IgGs or antibody fragments), molecular targets (e.g., extracellular matrix components and cell membrane antigens) and cytokine payloads have been considered for the development of this novel class of biopharmaceuticals. This review presents the basic concepts on the design and engineering of immunocytokines, reviews their potential limitations, points out emerging opportunities and summarizes key features of preclinical and clinical-stage products.

Anti-cancer Therapies Employing IL-2 Cytokine Tumor Targeting: Contribution of Innate, Adaptive and Immunosuppressive Cells in the Anti-tumor Efficacy

Antibody-cytokine fusion proteins (immunocytokine) exert a potent anti-cancer effect; indeed, they target the immunosuppressive tumor microenvironment (TME) due to a specific anti-tumor antibody linked to immune activating cytokines. Once bound to the target tumor, the interleukin-2 (IL-2) immunocytokines composed of either full antibody or single chain Fv conjugated to IL-2 can promote the in situ recruitment and activation of natural killer (NK) cells and cytotoxic CD8⁺ T lymphocytes (CTL). This recruitment induces a TME switch toward a classical T helper 1 (Th1) anti-tumor immune response, supported by the cross-talk between NK and dendritic cells (DC). Furthermore, some IL-2 immunocytokines have been largely shown to trigger tumor cell killing by antibody dependent cellular cytotoxicity (ADCC), through Fcγ receptors engagement. The modulation of the TME can be also achieved with immunocytokines conjugated with a mutated form of IL-2 that impairs regulatory T (Treg) cell proliferation and activity. Preclinical animal models and more recently phase I/II clinical trials have shown that IL-2 immunocytokines can avoid the severe toxicities of the systemic administration of high doses of soluble IL-2 maintaining the potent anti-tumor effect of this cytokine. Also, very promising results have been reported using IL-2 immunocytokines delivered in combination with other immunocytokines, chemo-, radio-, anti-angiogenic therapies, and blockade of immune checkpoints. Here, we summarize and discuss the most relevant reported studies with a focus on: (a) the effects of IL-2 immunocytokines on innate and adaptive anti-tumor immune cell responses as well as immunosuppressive Treg cells and (b) the approaches to circumvent IL-2-mediated severe toxic side effects.

Outcomes and Predictive Factors of Isolated Limb Infusion for Patients with In-transit Melanoma in China

PURPOSE

This study was designed to evaluate the efficacy of isolated limb infusion (ILI) treatment in Chinese patients with in-transit melanoma and to identify factors predictive of the outcome.

METHODS

A total of 150 patients with in-transit melanoma who received a single ILI between 2007 and 2016 were identified from a prospectively collected database.

RESULTS

All patients had AJCC Stages IIIb, IIIc, and IV disease. Acral lentiginous melanoma (ALM) accounted for 79% of patients, and 59% had a high burden of disease (BOD). The complete response (CR) and partial response (PR) rates were 6 and 35%, respectively. Forty-five percent of patients experienced grade III-IV limb toxicities, but no grade V toxicity was observed. Patients with a low BOD, high limb temperature, high peak creatine phosphokinase (CK) level, and grade III-IV limb toxicity achieved higher response rates. Stage IV disease and high BOD were associated with worse infield progression-free survival (PFS) and overall survival (OS), whereas patients with CR or PR to ILI had better infield PFS and OS. Multivariate analyses showed that disease stage, BOD, and a CR were independent predictors of infield PFS, whereas disease stage and a response to ILI were independent predictors of OS.

CONCLUSIONS

ILI is well-tolerated but the response rate in Chinese patients was lower than that reported in US and Australian studies. The prevalence of the ALM histological type, advanced disease stages, and a high BOD may be the main reasons for this. A response to ILI, BOD, and disease stage are prognostic factors for survival.

Solanum incanum extract (SR-T100) induces melanoma cell apoptosis and inhibits established lung metastasis

Melanoma, a cancer derived from melanocytes, is one of the most chemoresistant cancers and tends to metastasize. Once it metastasizes, the prognosis is poor. Even with the recent advancement of targeted therapy and immunotherapy, the prognosis remains discouraging. SR-T100, a Solanum incanum extract, shows anticancer effects against several cancers; however, its therapeutic efficacy against melanoma and established metastasis remains unknown. In this study, we showed that SR-T100 induces apoptosis, DNA damage, and G0/G1 cell cycle arrest in murine B16 melanoma cells in vitro. In vivo, intralesional injection of SR-T100 decreased the tumor size of the regional melanoma in the foot pad. Moreover, intraperitoneal injection of SR-T100 inhibited the growth and the number of established melanoma metastases in the lungs. Our study highlights SR-T100 as a potential novel treatment for established tumors from regional and metastatic melanoma.

Tumor-related interleukins: old validated targets for new anti-cancer drug development

In-depth knowledge of cancer molecular and cellular mechanisms have revealed a strong regulation of cancer development and progression by the inflammation which orchestrates the tumor microenvironment. Immune cells, residents or recruited, in the inflammation milieu can have rather contrasting effects during cancer development. Accumulated clinical and experimental data support the notion that acute inflammation could exert an immunoprotective effect leading to tumor eradication. However, chronic immune response promotes tumor growth and invasion. These reactions are mediated by soluble mediators or cytokines produced by either host immune cells or tumor cells themselves. Herein, we provide an overview of the current understanding of the role of the best-validated cytokines involved in tumor progression, IL-1, IL-4 and IL-6; in addition to IL-2 cytokines family, which is known to promote tumor eradication by immune cells. Furthermore, we summarize the clinical attempts to block or bolster the effect of these tumor-related interleukins in anti-cancer therapy development.