Survival follow-up and ipilimumab retreatment of patients with advanced melanoma who received ipilimumab in prior phase II studies

CTLA4 Alteration and Neurologic Manifestations: A New Family with Large Phenotypic Variability and Literature Review

Cytotoxic-T-lymphocyte-antigen-4 (CTLA-4), a member of the immunoglobulin superfamily, is an essential negative regulator of immune responses that is constitutively expressed on both regulatory (Treg) and activated T cells. To date, heterozygous germline variants in CTLA4, leading to haploinsufficiency, have been associated with several immunological disorders, including hypogammaglobulinemia, multi-organ autoimmunity, lymphoproliferative disorders, and enlarged lymphoid organs. Indeed, CTLA4 carriers display highly heterogeneous clinical manifestations with a phenotypic spectrum ranging from asymptomatic carrier status to fatal autoimmunity. Here, we describe a family with autoimmune phenotypes (Hashimoto thyroiditis, psoriasiform dermatitis, celiac disease/inflammatory bowel disease, and rheumatoid arthritis), segregating across three different generations due to a recurrent missense variant [c.436G>A, p.(Gly146Arg)] in the CTLA4 gene. Interestingly, the proband showed prominent neurological manifestations, including seizures, hydrocephalus, and demyelination, which are less frequently reported in individuals with pathogenic variants in CTLA4. A detailed literature review of neurologic features that have been reported so far in CTLA4 carriers is also provided.

Exploring the Potential of Nanocarriers for Cancer Immunotherapy: Insights into Mechanism, Nanocarriers, and Regulatory Perspectives

Immunotherapy is a cutting-edge approach that leverages sophisticated technology to target tumor-specific antibodies and modulate the immune system to eradicate cancer and enhance patients' quality of life. Bioinformatics and genetic science advancements have made it possible to diagnose and treat cancer patients using immunotherapy technology. However, current immunotherapies against cancer have limited clinical benefits due to cancer-associated antigens, which often fail to interact with immune cells and exhibit insufficient therapeutic targeting with unintended side effects. To surmount this challenge, nanoparticle systems have emerged as a potential strategy for transporting immunotherapeutic agents to cancer cells and activating immune cells to combat tumors. Consequently, this process potentially generates an antigen-specific T cells response that effectively suppresses cancer growth. Furthermore, nanoplatforms have high specificity, efficacy, diagnostic potential, and imaging capabilities, making them promising tools for cancer treatment. However, this informative paper delves into the various available immunotherapies, including CAR T cells therapy and immune checkpoint blockade, cytokines, cancer vaccines, and monoclonal antibodies. Furthermore, the paper delves into the concept of theragnostic nanotechnology, which integrates therapy and diagnostics for a more personalized treatment approach for cancer therapy. Additionally, the paper covers the potential benefits of different nanocarrier systems, including marketed immunotherapy products, clinical trials, regulatory considerations, and future prospects for cancer immunotherapy.

Efficacy and safety of immune checkpoint inhibitors rechallenge in advanced solid tumors: a systematic review and meta-analysis

Introduction

The efficacy and safety of re-administration of immune checkpoint inhibitors (ICIs) in advanced solid tumors lacks consensus and is of great concern to clinicians. This study aimed to investigate the efficacy and adverse effects of ICIs rechallenges in advanced solid tumors.

Methods

We systematically searched the databases of PubMed, Embase, the Cochrane Library, and the China National Knowledge Infrastructure (CNKI), and screened the relevant literature according to the inclusion and exclusion criteria. Meanwhile, we conducted a meta-analysis of objective response rates (ORR), disease control rates (DCR), and immune-related adverse events (irAEs) for reuse of ICIs using Freeman-Tukey double arcsine transformation method.

Results

Sixty eligible studies were included in the meta-analysis, and the results revealed that those who discontinued ICIs therapy and reused ICIs had an ORR of 21.6% [95% confidence interval (CI): 17.6, 25.7] and a DCR of 55.8% (95% CI: 50.0, 61.5). The overall incidence for grade ≥ 3 irAEs was 16.7% (95% CI: 11.8, 22.2). In the subgroup analysis, patients with renal cell carcinoma presented superior efficacy with an ORR of 30.9%, which was higher than that of melanoma (24.3%) and non-small cell lung cancer (NSCLC) (10.1%). Patients who have been treated with single-agent ICIs, re-treatment with a combination of ICIs directing different targets presents better outcomes, with ORR of 22.5% and DCR of 38%, respectively, compared with those patients who continue to use a single agent.

Conclusion

Patients with advanced solid tumors who have relapsed or progressed after prior treatment with ICIs may benefit from ICIs rechallenge, with a comparable incidence of grade ≥ 3 irAEs to those previously treated with ICIs.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023407409.

Estimating scenarios for survival time in patients with advanced melanoma receiving immunotherapy and targeted therapy

BACKGROUND

We aim to provide survival scenario estimates for patients with advanced melanoma starting targeted therapies and immunotherapies.

MATERIALS AND METHODS

We sought randomized trials of targeted therapies and immunotherapies for advanced melanoma and recorded the following percentiles (represented survival scenario) from each overall survival (OS) curve: 90th (worst-case), 75th (lower-typical), 50th (median), 25th (upper-typical), and 10th (best-case). We tested whether these scenarios can be estimated for each OS curve by multiplying its median by 4 multiples: 0.25 (worst-case), 0.5 (lower-typical), 2 (upper-typical), and 3 (best-case).

RESULTS

We identified 15 trials with 8025 patients. For first-line combination targeted therapy treatment groups, the median (interquartile range, IQR) in months for each percentile was: 90th, 6.2 (6.0-6.5); 75th, 11.3 (11.3-11.4); and median, 24.4 (23.5-25.3). For the first-line combination immunotherapy treatment group, the percentiles in months were: 90th, 3.9 (2.8-4.5); 75th, 13.4 (10.1-15.4), median 73 (not applicable). In targeted therapy groups, simple multiples of the median OS were accurate for estimating the 90th percentile in 80%; 75th percentile in 40%; 25th percentile in 100%. In immunotherapy groups, these multiples were accurate at 0% for the 90th percentile, and 43% for the 75th percentile. The 90th percentile (worst-case scenario) was better estimated as 1/6× median OS, and the 75th percentile (lower-typical) as 1/3× median OS.

CONCLUSIONS

Simple multiples of the median OS are a useful framework to estimate scenarios for survival for patients receiving targeted therapies, not immunotherapy. Longer follow-up is required to estimate upper-typical and best-case scenarios.

Review on radiomic analysis in 18F-fluorodeoxyglucose positron emission tomography for prediction of melanoma outcomes

Over the past decade, several strategies have revolutionized the clinical management of patients with cutaneous melanoma (CM), including immunotherapy and targeted tyrosine kinase inhibitor (TKI)-based therapies. Indeed, immune checkpoint inhibitors (ICIs), alone or in combination, represent the standard of care for patients with advanced disease without an actionable mutation. Notably BRAF combined with MEK inhibitors represent the therapeutic standard for disease disclosing BRAF mutation. At the same time, FDG PET/CT has become part of the routine staging and evaluation of patients with cutaneous melanoma. There is growing interest in using FDG PET/CT measurements to predict response to ICI therapy and/or target therapy. While semiquantitative values such as standardized uptake value (SUV) are limited for predicting outcome, new measures including tumor metabolic volume, total lesion glycolysis and radiomics seem promising as potential imaging biomarkers for nuclear medicine. The aim of this review, prepared by an interdisciplinary group of experts, is to take stock of the current literature on radiomics approaches that could improve outcomes in CM.

Immune-Related Adverse Events Due to Cancer Immunotherapy: Immune Mechanisms and Clinical Manifestations

The landscape of cancer treatment has undergone a significant transformation with the introduction of Immune Checkpoint Inhibitors (ICIs). Patients undergoing these treatments often report prolonged clinical and radiological responses, albeit with a potential risk of developing immune-related adverse events (irAEs). Here, we reviewed and discussed the mechanisms of action of ICIs and their pivotal role in regulating the immune system to enhance the anti-tumor immune response. We scrutinized the intricate pathogenic mechanisms responsible for irAEs, arising from the evasion of self-tolerance checkpoints due to drug-induced immune modulation. We also summarized the main clinical manifestations due to irAEs categorized by organ types, detailing their incidence and associated risk factors. The occurrence of irAEs is more frequent when ICIs are combined; with neurological, cardiovascular, hematological, and rheumatic irAEs more commonly linked to PD1/PD-L1 inhibitors and cutaneous and gastrointestinal irAEs more prevalent with CTLA4 inhibitors. Due to the often-nonspecific signs and symptoms, the diagnosis of irAEs (especially for those rare ones) can be challenging. The differential with primary autoimmune disorders becomes sometimes intricate, given the clinical and pathophysiological similarities. In conclusion, considering the escalating use of ICIs, this area of research necessitates additional clinical studies and practical insights, especially the development of biomarkers for predicting immune toxicities. In addition, there is a need for heightened education for both clinicians and patients to enhance understanding and awareness.

Efficacy and safety analysis of immune checkpoint inhibitor rechallenge therapy in locally advanced and advanced non-small cell lung cancer: a retrospective study

Background

Immune checkpoint inhibitors (ICIs) have dramatically changed the first-line treatment pattern of non-small cell lung cancer (NSCLC) without driver gene alterations. However, the optimal choice for second-line treatment after initial treatment with ICIs is unclear. This study aimed to clarify the efficacy and safety of ICI rechallenge therapy in locally advanced and advanced NSCLC.

Methods

We retrospectively analyzed the histories of 224 patients with locally advanced or advanced NSCLC treated with programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors alone or in combination with chemotherapy and/or antiangiogenic therapy in first-line treatment. Progression-free survival 2 (PFS2) was the time from the first defined progress disease (PD) to the second disease progression or death. Efficacy evaluation was performed directly in accordance with RECIST v1.1 criteria. Adverse events (AEs) were graded following the National Cancer Institute Common Terminology Criteria for Adverse Events v5.0. Survival data were estimated using the Kaplan-Meier method or Cox survival regression model and compared using the log-rank test in overall cohort and other subgroups.

Results

There were no significant differences in objective response rate (ORR) and median PFS2 (mPFS2) between the ICI rechallenge group and non-rechallenge group (ORR: 10.3% vs. 15.3%, P=0.308; mPFS2: 5.33 vs. 4.40 months, P=0.715). And the ICI rechallenge group showed no new safety signals compared with non-rechallenge group. In ICI rechallenge group, patients resistant to first-line immunotherapy had a lower ORR and shorter PFS2 compared with those who responded to initial ICIs treatment (ORR: 7.0% vs. 17.6%, P=0.038; mPFS2: 3.68 vs. 5.91 months, P=0.014). No significant difference in mPFS2 was observed among different second-line treatment groups (P=0.362). Radiotherapy in second-line treatment and ICI rechallenge therapy were not the main factors affecting PFS2.

Conclusions

ICI rechallenge therapy beyond disease progression did not improve clinical outcomes in patients with NSCLC, but no new safety signals emerged. However, patients with favorable response to initial ICIs treatment still showed significant efficacy of subsequent ICI rechallenge therapy.

From clinical management to personalized medicine: novel therapeutic approaches for ovarian clear cell cancer

Ovarian clear-cell cancer is a rare subtype of epithelial ovarian cancer with unique clinical and biological features. Despite optimal cytoreductive surgery and platinum-based chemotherapy being the standard of care, most patients experience drug resistance and a poor prognosis. Therefore, novel therapeutic approaches have been developed, including immune checkpoint blockade, angiogenesis-targeted therapy, ARID1A synthetic lethal interactions, targeting hepatocyte nuclear factor 1β, and ferroptosis. Refining predictive biomarkers can lead to more personalized medicine, identifying patients who would benefit from chemotherapy, targeted therapy, or immunotherapy. Collaboration between academic research groups is crucial for developing prognostic outcomes and conducting clinical trials to advance treatment for ovarian clear-cell cancer. Immediate progress is essential, and research efforts should prioritize the development of more effective therapeutic strategies to benefit all patients.

Efficacy of Immune Checkpoint Inhibitor (ICI) Rechallenge in Advanced Melanoma Patients' Responders to a First Course of ICI: A Multicenter National Retrospective Study of the French Group of Skin Cancers (Groupe de Cancérologie Cutanée, GCC)

BACKGROUND

The long-term effectiveness of immune checkpoint inhibitor (ICI) rechallenge for progressive or recurrent advanced melanoma following previous disease control induced by ICI has not been thoroughly described in the literature.

PATIENTS AND METHODS

In this retrospective multicenter national real-life study, we enrolled patients who had been rechallenged with an ICI after achieving disease control with a first course of ICI, which was subsequently interrupted. The primary objective was to evaluate tumor response, while the secondary objectives included assessing the safety profile, identifying factors associated with tumor response, and evaluating survival outcomes.

RESULTS

A total of 85 patients from 12 centers were included in the study. These patients had advanced (unresectable stage III or stage IV) melanoma that had been previously treated and controlled with a first course of ICI before undergoing rechallenge with ICI. The rechallenge treatments consisted of pembrolizumab (n = 44, 52%), nivolumab (n = 35, 41%), ipilimumab (n = 2, 2%), or ipilimumab plus nivolumab (n = 4, 5%). The best overall response rate was 54%. The best response was a complete response in 30 patients (35%), a partial response in 16 patients (19%), stable disease in 18 patients (21%) and progressive disease in 21 patients (25%). Twenty-eight adverse events (AEs) were reported in 23 patients (27%), including 18 grade 1-2 AEs in 14 patients (16%) and 10 grade 3-4 AEs in nine patients (11%). The median progression-free survival (PFS) was 21 months, and the median overall survival (OS) was not reached at the time of analysis. Patients who received another systemic treatment (chemotherapy, targeted therapy or clinical trial) between the two courses of ICI had a lower response to rechallenge (p = 0.035) and shorter PFS (p = 0.016).

CONCLUSION

Rechallenging advanced melanoma patients with ICI after previous disease control induced by these inhibitors resulted in high response rates (54%) and disease control (75%). Therefore, ICI rechallenge should be considered as a relevant therapeutic option.

The role of mitochondria in the resistance of melanoma to PD-1 inhibitors

Malignant melanoma is one of the most common tumours and has the highest mortality rate of all types of skin cancers worldwide. Traditional and novel therapeutic approaches, including surgery, targeted therapy and immunotherapy, have shown good efficacy in the treatment of melanoma. At present, the mainstay of treatment for melanoma is immunotherapy combined with other treatment strategies. However, immune checkpoint inhibitors, such as PD-1 inhibitors, are not particularly effective in the clinical treatment of patients with melanoma. Changes in mitochondrial function may affect the development of melanoma and the efficacy of PD-1 inhibitors. To elucidate the role of mitochondria in the resistance of melanoma to PD-1 inhibitors, this review comprehensively summarises the role of mitochondria in the occurrence and development of melanoma, targets related to the function of mitochondria in melanoma cells and changes in mitochondrial function in different cells in melanoma resistant to PD-1 inhibitors. This review may help to develop therapeutic strategies for improving the clinical response rate of PD-1 inhibitors and prolonging the survival of patients by activating mitochondrial function in tumour and T cells.

Immunotherapy Resumption/Rechallenge in Melanoma Patients after Toxicity: Do We Have Another Chance?

Introduction: Immune checkpoint inhibitors (ICIs) have radically changed the prognosis of several neoplasias, among them metastatic melanoma. In the past decade, some of these new drugs have appeared together with a new toxicity spectrum previously unknown to clinicians, until now. A common situation in daily practice is that a patient experiences toxicity due to this type of drug and we need to resume or rechallenge treatment after resolving the adverse event. Methods: A PubMed literature review was carried out. Results: The published data regarding the resumption or rechallenge of ICI treatment in melanoma patients is scarce and heterogeneous. Depending on the study reviewed, the recurrence incidence of grade 3–4 immune-related adverse events (irAEs) ranged from 18% to 82%. Conclusion: It is possible to resume or rechallenge, but each patient should be evaluated by a multidisciplinary team for close monitoring and assessment of the risk/benefit ratio before initiating treatment.

Efficacy of ipilimumab 3mg/kg following progression on low dose ipilimumab in metastatic melanoma

BACKGROUND

Differing doses of ipilimumab (IPI) are used in combination with an anti-PD1 antibody in advanced melanoma. There is no data on the outcomes of patients who progress following low-dose IPI (< 3 mg/kg) and are subsequently treated with IPI 3 mg/kg (IPI3). We conducted a multicentre retrospective survey to assess the efficacy of this strategy.

METHODS

Patients with resected stage III, unresectable stage III or IV melanoma who received low dose IPI (< 3 mg/kg) with an anti-PD1 antibody with recurrence (neo/adjuvant) or progressive disease (metastatic), who then received IPI3± anti-PD1 antibody were eligible. Best investigator-determined Response Evaluation Criteria in Solid Tumours response, progression-free survival (PFS) and overall survival (OS) were analysed.

RESULTS

Total 36 patients received low-dose IPI with an anti-PD1 antibody, 18 (50%) in the neo/adjuvant and 18 (50%) in the metastatic setting. Of which, 20 (56%) had primary resistance and 16 (44%) had acquired resistance. All patients received IPI3 for unresectable stage III or IV melanoma; median age 60 (29-78), 18 (50%) M1d disease, 32 (89%) Eastern Cooperative Oncology Group performance status 0-1. Around 35 (97%) received IPI3 with nivolumab and 1 received IPI3 alone. The response rate to IPI3 was 9/36 (25%). In patients with primary resistance, the response rate was 6/20 (30%). After a median follow-up of 22 months (95% CI: 15-27 months), the median PFS and OS were not reached in patients who responded; 1-year PFS and OS were 73% and 100%, respectively.

CONCLUSIONS

IPI3 following recurrence/progression on low dose IPI has clinical activity, including in primary resistance. IPI dosing is therefore critical in a subset of patients.

Rechallenge of immunotherapy beyond progression in patients with extensive-stage small-cell lung cancer

Background: Rechallenge of immunotherapy beyond progression (RIBP) has been demonstrably effective in a variety of cancers. Our study aims to investigate the efficacy of RIBP in small-cell lung cancer (SCLC) patients under real-world conditions.

Methods: SCLC patients who experienced progressive disease after receiving programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) inhibitors combined with chemotherapy from January 2017 to October 2021 were enrolled. The study population was divided into two groups: the RIBP group and the discontinuation of immunotherapy beyond progression (DIBP) group. Inverse propensity score weighting (IPSW) method was used to balance the clinical baseline characteristics. The short-term and long-term efficacy of the two groups was compared.

Results: 100 SCLC patients were included in this study. There were 45 patients in the RIBP group and 55 patients in the DIBP group. The disease control rate (DCR) and the proportion of durable clinical benefit (DCB) were significantly higher in the RIBP group (DCR: 79.7% vs. 55.7%, p = 0.027; DCB: 40.7 vs. 20.7%, p = 0.025) after weighting. The median progressive-free survival (PFS) in the RIBP group was significantly longer than the DIBP group in the total population (mPFS: 4.8 vs. 2.4 months, p = 0.002), while there was no significant difference in overall survival (OS) of the two groups (mOS: 17.4 vs. 8.0 months, p = 0.098). In the weighted first-line initial immunotherapy subgroup, PFS and OS were significantly improved in the RIBP group (mPFS: 4.5 vs. 2.8 months, p = 0.017; mOS: 11.6 vs. 5.4 months, p = 0.028). After weighting, the RIBP group had a significantly longer PFS than the DIBP group in the SD/PD response to the initial immunotherapy subgroup (mPFS: 6.8 vs. 1.8 months, p = 0.026).

Conclusion: Rechallenge of PD-1/PD-L1 inhibitors could bring benefits to SCLC patients, especially in the first-line initial immunotherapy subgroup or SD/PD response to the initial immunotherapy subgroup.

Paired primary and metastatic lesions of patients with ipilimumab-treated melanoma: high variation in lymphocyte infiltration and HLA-ABC expression whereas tumor mutational load is similar and correlates with clinical outcome

BACKGROUND

Immune checkpoint inhibitors (ICI) can lead to long-term responses in patients with metastatic melanoma. Still many patients with melanoma are intrinsically resistant or acquire secondary resistance. Previous studies have used primary or metastatic tumor tissue for biomarker assessment. Especially in melanoma, metastatic lesions are often present at different anatomical sites such as skin, lymph nodes, and visceral organs. The anatomical site may directly affect the tumor microenvironment (TME). To evaluate the impact of tumor evolution on the TME and on ICI treatment outcome, we directly compared paired primary and metastatic melanoma lesions for tumor mutational burden (TMB), HLA-ABC status, and tumor infiltrating lymphocytes (TILs) of patients that received ipilimumab.

METHODS

TMB was analyzed by sequencing primary and metastatic melanoma lesions using the TruSight Oncology 500 assay. Tumor tissues were subjected to multiplex immunohistochemistry to assess HLA-ABC status and for the detection of TIL subsets (B cells, cytotoxic T cells, helper T cells, and regulatory T cells), by using a machine-learning algorithm.

RESULTS

While we observed a very good agreement between TMB of matched primary and metastatic melanoma lesions (intraclass coefficient=0.921), such association was absent for HLA-ABC status, TIL density, and subsets thereof. Interestingly, analyses of different metastatic melanoma lesions within a single patient revealed that TIL density and composition agreed remarkably well, rejecting the hypothesis that the TME of different anatomical sites affects TIL infiltration. Similarly, the HLA-ABC status between different metastatic lesions within patients was also comparable. Furthermore, high TMB, of either primary or metastatic melanoma tissue, directly correlated with response to ipilimumab, whereas lymphocyte density or composition did not. Loss of HLA-ABC in the metastatic lesion correlated to a shorter progression-free survival on ipilimumab.

CONCLUSIONS

We confirm the link between TMB and HLA-ABC status and the response to ipilimumab-based immunotherapy in melanoma, but no correlation was found for TIL density, neither in primary nor metastatic lesions. Our finding that TMB between paired primary and metastatic melanoma lesions is highly stable, demonstrates its independency of the time point and location of acquisition. TIL and HLA-ABC status in metastatic lesions of different anatomical sites are highly similar within an individual patient.

Oxidative Stress in Cancer Immunotherapy: Molecular Mechanisms and Potential Applications

Immunotherapy is an effective treatment option that revolutionizes the management of various cancers. Nevertheless, only a subset of patients receiving immunotherapy exhibit durable responses. Recently, numerous studies have shown that oxidative stress induced by reactive oxygen species (ROS) plays essential regulatory roles in the tumor immune response, thus regulating immunotherapeutic effects. Specifically, studies have revealed key roles of ROS in promoting the release of tumor-associated antigens, manipulating antigen presentation and recognition, regulating immune cell phenotypic differentiation, increasing immune cell tumor infiltration, preventing immune escape and diminishing immune suppression. In the present study, we briefly summarize the main classes of cancer immunotherapeutic strategies and discuss the interplay between oxidative stress and anticancer immunity, with an emphasis on the molecular mechanisms underlying the oxidative stress-regulated treatment response to cancer immunotherapy. Moreover, we highlight the therapeutic opportunities of manipulating oxidative stress to improve the antitumor immune response, which may improve the clinical outcome.

Immune Checkpoint Inhibitor Rechallenge and Resumption: a Systematic Review

PURPOSE OF THE REVIEW

The reintroduction of immune checkpoint inhibitors (ICIs) after disease progression (rechallenge) or immune-related adverse events (irAEs) recovering (resumption) raises questions in terms of efficacy and safety.

RECENT FINDINGS

Here, we reviewed literature data about ICIs rechallenge/resumption in cancer patients along with their clinical characteristics to explore those factors associated with better outcomes. Heterogenous results were pointed out across rechallenge studies with an overall response rate between 0 and 54%, and a progression free survival ranged from 1.5 to 12.9 months and an overall survival between 6.5 and 23.8 months. Better outcomes have been recorded in patients with good ECOG PS, longer duration of initial ICI, discontinuation reason of initial ICI other than progression, and those who received ICI sequence other than the switch between anti-PD1 and anti-PDL1. Studies about ICI resumption highlighted that certain types of irAEs were more likely to relapse at retreatment. These results suggest that ICI rechallenge/resumption can be an interesting strategy for selected patients.

Holistic Approach to Immune Checkpoint Inhibitor-Related Adverse Events

Immune checkpoint inhibitors (ICIs) block inhibitory molecules, such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), or its ligand, programmed cell death protein ligand 1 (PD-L1) and enhance antitumor T-cell activity. ICIs provide clinical benefits in a percentage of patients with advanced cancers, but they are usually associated with a remarkable spectrum of immune-related adverse events (irAEs) (e.g., rash, colitis, hepatitis, pneumonitis, endocrine, cardiac and musculoskeletal dysfunctions). Particularly patients on combination therapy (e.g., anti-CTLA-4 plus anti-PD-1/PD-L1) experience some form of irAEs. Different mechanisms have been postulated to explain these adverse events. Host factors such as genotype, gut microbiome and pre-existing autoimmune disorders may affect the risk of adverse events. Fatal ICI-related irAEs are due to myocarditis, colitis or pneumonitis. irAEs usually occur within the first months after ICI initiation but can develop as early as after the first dose to years after ICI initiation. Most irAEs resolve pharmacologically, but some appear to be persistent. Glucocorticoids represent the mainstay of management of irAEs, but other immunosuppressive drugs can be used to mitigate refractory irAEs. In the absence of specific trials, several guidelines, based on data from retrospective studies and expert consensus, have been published to guide the management of ICI-related irAEs.

Tumor-associated macrophages in cancer: recent advancements in cancer nanoimmunotherapies

Cancer immunotherapy has emerged as a novel cancer treatment, although recent immunotherapy trials have produced suboptimal outcomes, with durable responses seen only in a small number of patients. The tumor microenvironment (TME) has been shown to be responsible for tumor immune escape and therapy failure. The vital component of the TME is tumor-associated macrophages (TAMs), which are usually associated with poor prognosis and drug resistance, including immunotherapies, and have emerged as promising targets for cancer immunotherapy. Recently, nanoparticles, because of their unique physicochemical characteristics, have emerged as crucial translational moieties in tackling tumor-promoting TAMs that amplify immune responses and sensitize tumors to immunotherapies in a safe and effective manner. In this review, we mainly described the current potential nanomaterial-based therapeutic strategies that target TAMs, including restricting TAMs survival, inhibiting TAMs recruitment to tumors and functionally repolarizing tumor-supportive TAMs to antitumor type. The current understanding of the origin and polarization of TAMs, their crucial role in cancer progression and prognostic significance was also discussed in this review. We also highlighted the recent evolution of chimeric antigen receptor (CAR)-macrophage cell therapy.

REchallenge of NIVOlumab (RENIVO) or Nivolumab-Ipilimumab in Metastatic Renal Cell Carcinoma: An Ambispective Multicenter Study

Introduction. Immune checkpoint inhibitors (ICI) have been approved for front-line therapy in metastatic renal cell carcinoma (mRCC). However, progressive disease often occurs and subsequent therapies are needed. ICI rechallenge may be an option, but there is a lack of data regarding efficacy and prognostic factors. We assessed efficacy of ICI rechallenge and factors associated with better outcomes. Patients and Methods. This ambispective multicenter study included 45 mRCC patients rechallenged with nivolumab ± ipilimumab between 2014 and 2020. Primary endpoint was investigator-assessed best objective response rate (ORR) for ICI rechallenge (ICI-2). Factors associated with ICI-2 progression-free survival (PFS) were evaluated with multivariate Cox models. Results. ORR was 51% (n = 23) at first ICI therapy (ICI-1) and 16% (n = 7) for ICI-2. Median PFS was 11.4 months (95% CI, 9.8–23.5) and 3.5 months (95% CI, 2.8–9.7), and median overall survival was not reached (NR) (95% CI, 37.8–NR) and 24 months (95% CI, 9.9–NR) for ICI-1 and ICI-2, respectively. Factors associated with poorer ICI-2 PFS were a high number of metastatic sites, presence of liver metastases, use of an intervening treatment between ICI regimens, Eastern Cooperative Oncology Group performance status ≥2, and poor International Metastatic RCC Database Consortium score at ICI-2 start. Conversely, ICI-1 PFS >6 months was associated with better ICI-2 PFS. In multivariate analysis, there were only statistical trends toward better ICI-2 PFS in patients with ICI-1 PFS >6 months ( $p=0.07$ ) and toward poorer ICI-2 PFS in patients who received a treatment between ICI regimens ( $p=0.07$ ). Conclusion. Rechallenge with nivolumab-based ICI has some efficacy in mRCC. We identified various prognostic factors in univariate analysis but only statistical trends in multivariate analysis. Our findings bring new evidence on ICI rechallenge and preliminary but unique data that may help clinicians to select patients who will benefit from this strategy.

Safety of Immune Checkpoint Inhibitor Resumption after Interruption for Immune-Related Adverse Events, a Narrative Review

Immune checkpoint inhibitors (ICIs) have become the standard of care for several types of cancer due to their superiority in terms of survival benefits in first- and second-line treatments compared to conventional therapies, and they present a better safety profile (lower absolute number of grade 1-5 adverse events), especially if used in monotherapy. However, the pattern of ICI-related adverse events is totally different, as they are characterized by the development of specific immune-related adverse events (irAEs) that are unique in terms of the organs involved, onset patterns, and severity. The decision to resume ICI treatment after its interruption due to irAEs is challenged by the need for tumor control versus the risk of occurrence of the same or different irAEs. Studies that specifically assess this point remain scarce, heterogenous and mostly based on small samples of patients or focused only on the recurrence rate of the same irAE after ICI resumption. Moreover, patients with grade ≥3 irAEs were excluded from many of these studies. Herein, we provide a narrative review on the field of safety of ICI resumption after interruption due to irAE(s).

Factors Determining Long-Term Antitumor Responses to Immune Checkpoint Blockade Therapy in Melanoma

With the increasing promise of long-term survival with immune checkpoint blockade (ICB) therapies, particularly for patients with advanced melanoma, clinicians and investigators are driven to identify prognostic and predictive factors that may help to identify individuals who are likely to experience durable benefit. Several ICB combinations are being actively developed to expand the armamentarium of treatments for patients who may not achieve long-term responses to ICB single therapies alone. Thus, negative predictive markers are also of great interest. This review seeks to deepen our understanding of the mechanisms underlying the durability of ICB treatments. We will discuss the currently available long-term data from the ICB clinical trials and real-world studies describing the survivorship of ICB-treated melanoma patients. Additionally, we explore the current treatment outcomes in patients rechallenged with ICB and the patterns of ICB resistance based on sites of disease, namely, liver or CNS metastases. Lastly, we discuss the landscape in melanoma in the context of prognostic or predictive factors as markers of long-term response to ICB.

Immune checkpoint inhibitors rechallenge in urological tumors: An extensive review of the literature

Immune checkpoint inhibitors (ICIs) have led to a significant change in the treatment of urological tumors where several agents are currently approved. Yet, most patients discontinue treatment due to disease progression or after the onset of severe immune-related adverse events (IRAEs). Following promising results in melanoma patients, retreatment with an ICI is receiving increasing attention as an attractive option for selected patients. We performed a literature review focusing on the feasibility, safety, timing and activity of ICI rechallenge in genitourinary cancers where very little information is available. We classified the different ICI retreatment strategies into three main clinical scenarios: retreatment after terminating a prior course of ICI while still on response; retreatment after interruption due to IRAEs; retreatment after progression while on ICI therapy. The pros and cons of these options in the field of urological tumors are then discussed, and critical suggestions proffered for the design of future clinical trials.

Neoantigen-Reactive T Cells: The Driving Force behind Successful Melanoma Immunotherapy

Simple Summary

Cancer immunotherapy is a revolutionary type of cancer therapy. It uses the patient’s own immune system to fight and potentially cure cancer. The first major breakthrough of immunotherapy came from successful clinical trials for melanoma treatments. Since then, researchers have focused on understanding the science behind immunotherapy, so that patients with other types of cancer may also benefit. One of the major findings is that the T cells in melanoma patients may recognize a specific type of tumor antigen, called neoantigens, and then kill tumor cells that present these neoantigens. The neoantigens mainly arise from the DNA mutations found in tumor cells. These mutations are translated into mutated proteins that are then distinguished by T cells. In this article, we discuss the critical role of T cells in immunotherapy, as well as the clinical trials that shaped the treatments for melanoma.

Abstract

Patients with metastatic cutaneous melanoma have experienced significant clinical responses after checkpoint blockade immunotherapy or adoptive cell therapy. Neoantigens are mutated proteins that arise from tumor-specific mutations. It is hypothesized that the neoantigen recognition by T cells is the critical step for T-cell-mediated anti-tumor responses and subsequent tumor regressions. In addition to describing neoantigens, we review the sentinel and ongoing clinical trials that are helping to shape the current treatments for patients with cutaneous melanoma. We also present the existing evidence that establishes the correlations between neoantigen-reactive T cells and clinical responses in melanoma immunotherapy.

Risks and benefits of reinduction ipilimumab/nivolumab in melanoma patients previously treated with ipilimumab/nivolumab

BACKGROUND

In melanoma patients who progress after prior ipilimumab/nivolumab (ipi/nivo) combination immunotherapy, there is no information regarding the risks and benefits of reinduction ipi/nivo.

METHODS

This was a retrospective review of 26 melanoma patients treated at Memorial Sloan Kettering Cancer Center (MSKCC) since 2012 who received reinduction ipi/nivo at least 6 months following completion of an initial course of ipi/nivo. We collected data on demographics, genetics, immune-related adverse events (irAEs), best overall responses (BORs), time to treatment failure (TTF) and overall survival (OS).

RESULTS

The BOR rate (complete response+partial response) was 74% (95% CI 52% to 90%) after the first course of ipi/nivo but only 23% (95% CI 8% to 45%)) after reinduction. Response to reinduction did not correlate with response to the initial course. Among the 16 patients who had an objective response to the first course, only four (25%) responded to reinduction. Of five patients who did not respond to the first course, one responded to reinduction. For all patients, median TTF was 5.3 months after reinduction; TTF was shorter for reinduction than for the first course in 85% of patients. Median OS from reinduction was 8.4 months; estimated 2-year OS was 18%. Although reinduction was associated with fewer irAEs than the initial course of ipi/nivo (58% of patients vs 85% of patients in the initial course), eight (31%) patients experienced at least one new irAE after the second course.

CONCLUSIONS

BOR rate and TTF were markedly less favorable after reinduction with ipi/nivo than after the initial course of ipi/nivo. Reinduction ipi/nivo was associated with frequent irAEs although less frequent than for the initial course.

Safety and Efficacy of the Rechallenge of Immune Checkpoint Inhibitors After Immune-Related Adverse Events in Patients With Cancer: A Systemic Review and Meta-Analysis

Introduction

Little evidence exists on the safety and efficacy of the rechallenge of immune checkpoint inhibitors (ICIs) after immune-related adverse events (irAEs) in patients with cancer.

Methods

We searched PubMed, Web of Science, Embase, and Cochrane for articles on ICI rechallenge after irAEs for systemic review and meta-analysis. The outcomes included the incidence and associated factors for safety and objective response rate (ORR) and disease control rate (DCR) for efficacy.

Results

A total of 789 ICI rechallenge cases from 18 cohort studies, 5 case series studies, and 54 case reports were included. The pooled incidence of all-grade and high-grade irAEs after rechallenge in patients with cancer was 34.2% and 11.7%, respectively. Compared with initial ICI treatment, rechallenge showed a higher incidence for all-grade irAEs (OR, 3.81; 95% CI, 2.15–6.74; p < 0.0001), but similar incidence for high-grade irAEs (p > 0.05). Types of initial irAEs (pneumonitis and global irAEs) and cancer (non-small cell lung cancer and multiple cancer) recapitulated these findings. Gastrointestinal irAEs and time interval between initial irAEs and ICI rechallenge were associated with higher recurrence of high-grade irAEs (p < 0.05), whereas initial anti-PD-1/PD-L1 antibodies were associated with a lower recurrence (p < 0.05). Anti-PD-1/PD-L1 antibodies rechallenge was associated with a lower all-grade irAE recurrence (p < 0.05). The pooled ORR and DCR after rechallenge were 43.1% and 71.9%, respectively, showing no significant difference compared with initial ICI treatment (p > 0.05).

Conclusions

ICI rechallenge after irAEs showed lower safety and similar efficacy outcomes compared with initial ICI treatment.

Systematic Review Registration

PROSPERO, identifier CRD42020191405.

Nanotechnology-based immunotherapies to combat cancer metastasis

Emerging concepts in nanotechnology have gained particular attention for their clinical translation of immunotherapies of cancer, autoimmune and infectious diseases. Several nanoconstructs have been engineered with unique structural, physicochemical, and functional features as robust alternatives for conventional chemotherapies. Traditional cancer therapies like chemotherapy, radiotherapy, and ultimately surgery are the most widely practiced in biomedical settings. Biomaterials and nanotechnology have introduced vehicles for drug delivery and have revolutionized the concept of the modern immunotherapeutic paradigm. Various types of nanomaterials, such as nanoparticles and, more specifically, drug-loaded nanoparticles are becoming famous for drug delivery applications because of safety, patient compliance, and smart action. Such therapeutic modalities have acknowledged regulatory endorsement and are being used in twenty-first-century clinical settings. Considering the emerging concepts and landscaping potentialities, herein, we spotlight and discuss nanoparticle-based immunotherapies as a smart and sophisticated drug delivery approach to combat cancer metastasis. The introductory part of this manuscript discusses a broad overview of cancer immunotherapy to understand better the tumor microenvironment and nanotechnology-oriented immunomodulatory strategies to cope with advanced-stage cancers. Following that, most addressable problems allied with conventional immunotherapies are given in comparison to nanoparticle-based immunotherapies. The later half of this work comprehensively highlights the requisite delivery of various bioactive entities with particular cases and examples. Finally, this review also encompasses a comprehensive concluding overview and future standpoints to strengthen a successful clinical translation of nanoparticle-based immunotherapies as a smart and sophisticated drug delivery approach.

Rechallenge of immune checkpoint inhibitors: A systematic review and meta-analysis

BACKGROUND

The role of immune checkpoint inhibitors (ICI) rechallenge in cancer patients is not defined. When ICIs are discontinued due to treatment completion or toxicity, another course of ICIs is feasible in clinical practice, but the amount of data is still quite limited to draw definitive conclusions. Here we report the results of a meta-analysis evaluating efficacy and safety of ICI rechallenge.

METHODS

PubMed, Embase, and Cochrane library were searched for studies reporting efficacy and safety of ICI rechallenge. Pooled analysis of response rate (ORR), median progression-free survival (mPFS) and median overall survival (mOS) were calculated.

RESULTS

A total of 49 studies were included in qualitative and quantitative pooled analysis Overall response rate, mPFS and mOS were 21.8 % (range 0-70 %), 4.9 months (range 0-19.1 months) and 15.6 months (range 5.1-39 months), respectively. Incidence of any grade and grade 3-4 adverse events were 52.2 % (range 4-100 %) and 21.5 % (range 0-97.8 %), respectively. In the subgroup of patients who had previously discontinued ICI because of disease progression ORR, mPFS and mOS were 15.2 %, 2.9 and 7.9 months. Patients who had previously discontinued ICI because of toxicity achieved an ORR of 44 % and a mPFS of 13.2 months with the rechallenge.

CONCLUSIONS

Our results suggest that rechallenge ICI is an active and feasible strategy, and it could be considered on an individual basis. However, this analysis is based on non-randomized studies. Prospective studies are needed to clarify the role of rechallenge after disease progression or adverse events.

Retrospective Analysis of Rechallenge with Ipilimumab in Patients with Metastatic Melanoma

Background

Checkpoint inhibitors are effective in the treatment of several types of cancer, either being used separately or in combination. Ipilimumab pioneered the treatment of metastatic melanoma, and nowadays, it has been used more frequently in combination with anti-PD-1. Since the development of anti-PD1 for melanoma, rechallenge with ipilimumab has not been considered, although its use was considered in early trials.

Cases

In this study, we analyzed 22 patients with metastatic melanoma who had benefited from the first treatment with ipilimumab, but eventually had progressive disease. They received ipilimumab at the same dose as the first treatment. Most of the patients received the second course after six months or more from the first treatment with ipilimumab. The median progression-free survival (mPFS) of the treatment with ipilimumab was 8.9 months, and the median progression-free survival of the second course was 6.3 months.

Conclusion

There are limited data on rechallenge with ipilimumab addressing progression-free survival (PFS). In our analysis, twenty-two patients treated with a second course of ipilimumab were analyzed and most of them had a significant benefit. Despite the current alternatives for salvage therapies, rechallenging with ipilimumab might be an alternative to be considered in patients who had initial benefit.

Re-induction ipilimumab following acquired resistance to combination ipilimumab and anti-PD-1 therapy

PURPOSE

Combination immunotherapy with nivolumab and ipilimumab has a high initial response rate in advanced melanoma; however, up to 55% of patients later progress. The efficacy and safety of ipilimumab re-induction in the setting of acquired resistance (AR) to combination immunotherapy is unknown.

METHODS

Patients with advanced melanoma who initially achieved a complete response, partial response or sustained stable disease to induction combination immunotherapy then progressed and were reinduced with ipilimumab (alone or in combination with anti-PD-1) and were analysed retrospectively. Demographics, disease characteristics, efficacy and toxicity were examined.

RESULTS

Forty-seven patients were identified from 12 centres. The response rate to reinduction therapy was 12/47 (26%), and disease control rate was 21/47 (45%). Responses appeared more frequent in patients who developed AR after ceasing induction immunotherapy (30% vs. 18%, P = 0.655). Time to AR was 11 months (95% confidence interval [CI], 8-15 months). After a median follow-up of 16 months (95% CI, 10-25 months), responders to reinduction had a median progression-free survival of 14 months (95% CI, 13, NR months), and in the whole cohort, the median overall survival from reinduction was 17 months (95% CI, 12-NR months). Twenty-seven (58%) immune-related adverse events (irAEs) were reported; 18 (38%) were grade 3/4, and in 11 of 27 (40%), the same irAE observed during induction therapy recurred.

CONCLUSIONS

Reinduction with ipilimumab ± anti-PD-1 has modest clinical activity. Clinicians should be attentive to the risk of irAEs, including recurrence of irAEs that occurred during induction therapy. Future studies are necessary to determine best management after resistance to combination immunotherapy.

NKTR-214 immunotherapy synergizes with radiotherapy to stimulate systemic CD8+ T cell responses capable of curing multi-focal cancer

Background

High-dose radiotherapy (RT) is known to be immunogenic, but is rarely capable of driving clinically relevant abscopal antitumor immunity as monotherapy. RT is known to increase antigen presentation, type I/II interferon responses, and immune cell trafficking to irradiated tumors. Bempegaldesleukin (NKTR-214) is a CD122-preferential interleukin 2 (IL-2) pathway agonist that has been shown to increase tumor-infiltrating lymphocytes, T cell clonality, and increase PD-1 expression. NKTR-214 has increased drug half-life, decreased toxicity, and increased CD8⁺ T cell and natural killer cell stimulation compared with IL-2.

Methods

Animals bearing bilateral subcutaneous MCA-205 fibrosarcoma or CT26 colorectal tumors were treated with NKTR-214, RT, or combination therapy, and tumor growth of irradiated and abscopal lesions was assessed. Focal RT was delivered using a small animal radiation research platform. Peripheral and tumor-infiltrating immune phenotype and functional analyses were performed by flow cytometry. RNA expression profiling from both irradiated and abscopal lesions was performed using microarray.

Results

We demonstrate synergy between RT of a single tumor and NKTR-214 systemic therapy resulting in dramatically increased cure rates of mice bearing bilateral tumors compared with RT or NKTR-214 therapy alone. Combination therapy resulted in increased magnitude and effector function of tumor-specific CD8⁺ T cell responses and increased trafficking of these T cells to both irradiated and distant, unirradiated, tumors.

Conclusions

Given the increasing role of hypofractionated and stereotactic body RT as standard of care treatments in the management of locally advanced and metastatic cancer, these data have important implications for future clinical trial development. The combination of RT and NKTR-214 therapy potently stimulates systemic antitumor immunity and should be evaluated for the treatment of patients with locally advanced and metastatic solid tumors.

Beyond First-Line Immunotherapy: Potential Therapeutic Strategies Based on Different Pattern Progressions: Oligo and Systemic Progression

First-line immune-checkpoint inhibitor (ICI)-based therapy has deeply changed the treatment landscape and prognosis in advanced non-small cell lung cancer (aNSCLC) patients with no targetable alterations. Nonetheless, a percentage of patients progressed on ICI as monotherapy or combinations. Open questions remain on patients' selection, the identification of biomarkers of primary resistance to immunotherapy and the treatment strategies to overcome secondary resistance to first-line immunotherapy. Local ablative approaches are the main therapeutic strategies in oligoprogressive disease, and their role is emerging in patients treated with immunotherapy. Many therapeutic strategies can be adapted in aNSCLC patients with systemic progression to personalize the treatment approach according to re-characterization of the tumors, previous ICI response, and type of progression. This review's aim is to highlight and discuss the current and potential therapeutic approaches beyond first-line ICI-based therapy in aNSCLC patients based on the pattern of disease progression (oligoprogression versus systemic progression).

Nivolumab discontinuation and retreatment in patients with relapsed or refractory Hodgkin lymphoma

Immune checkpoint inhibitors (ICI) have demonstrated high therapeutic efficacy in relapsed or refractory classical Hodgkin lymphoma (r/r cHL). Nevertheless, despite the accumulated data, the question of the ICI therapy duration and efficacy of nivolumab retreatment remains unresolved. In this retrospective study, in a cohort of 23 adult patients with r/r cHL who discontinued nivolumab in complete response (CR), the possibility of durable remission achievement (2-year PFS was 55.1%) was demonstrated. Retreatment with nivolumab has demonstrated efficacy with high overall response rate (ORR) and CR (67% and 33.3% respectively). At the final analysis, all patients were alive with median PFS of 16.5 months. Grade 3-4 adverse events (AEs) were reported in 36% of patients, and there was no deterioration in terms of nivolumab retreatment-associated complications.

Enhancing Immunity with Nanomedicine: Employing Nanoparticles to Harness the Immune System

The failure of immune responses to vaccines and dysfunctional immune responses to viral infection, tumor development, or neoantigens lead to chronic viral infection, tumor progression, or incomplete immune protection after vaccination. Thus, strategies to boost host immunity are a topic of intense research and development. Engineered nanoparticles (NPs) possess immunological properties and can be modified to promote improved local immune responses. Nanoparticle-based approaches have been employed to enhance vaccine efficacy and host immune responses to viral and tumor antigens, with impressive results. In this Perspective, we present an overview of studies, such as the one reported by Alam et al. in this issue of ACS Nano, in which virus-like particles have been employed to enhance immunity. We review the cellular cornerstones of effective immunity and discuss how NPs can harness these interactions to overcome the current obstacles in vaccinology and oncology. We also discuss the barriers to effective NP-mediated immune priming including (1) NP delivery to the site of interest, (2) the quality of response elicited, and (3) the potential of the response to overcome immune escape. Through this Perspective, we aim to highlight the value of nanomedicine not only in delivering therapies but also in coordinating the enhancement of host immune responses. We provide a forward-looking outlook for future NP-based approaches and how they could be tailored to promote this outcome.

Juniperus indica Bertol. extract synergized with cisplatin against melanoma cells via the suppression of AKT/mTOR and MAPK signaling and induction of cell apoptosis

Juniperus indica Bertol. is an herbal plant that belongs to the genus Juniperus, which is commonly used in traditional medicine to refresh the mind and for diuretic use. However, few studies have reported the function of J. indica Bertol. Hence, this study aimed to investigate the anti-tumor and synergistic potential of J. indica Bertol. extract (JIB extract) for melanoma cells. Our results indicated the anti-melanoma activity of JIB extract. JIB extract induced cell cycle arrest at the G₀/G₁ phase and decreased cyclin and cdk protein expressions. In addition, AKT/mTOR signaling and MAPK signaling were inhibited by JIB extract to suppress melanoma cell growth and proliferation. Additionally, JIB extract induced B16/F10 cell apoptosis via the caspase cascade. According to the JIB extract's anti-melanoma capacity, to assess the synergistic effects of cisplatin and JIB extract. The results demonstrated that JIB extract combined with cisplatin enhanced the inhibition of cell growth, proliferation, and survival through the obstruction of cell cycle progression and AKT/mTOR and MAPK signaling as well as the induction of cell apoptosis. Collectively, our results indicate that JIB extract showed anti-tumor effects and synergized with cisplatin against B16/F10 cells, indicating the possibility of JIB extract to be developed as adjuvant therapy for melanoma.

Current Advancements and Novel Strategies in the Treatment of Metastatic Melanoma

Melanoma is the deadliest form of skin cancer in the world with a growing incidence in North America. Contemporary treatments for melanoma include surgical resection, chemotherapy, and radiotherapy. However, apart from resection in early melanoma, the prognosis of patients using these treatments is typically poor. In the past decade, there have been significant advancements in melanoma therapies. Immunotherapies such as ipilimumab and targeted therapies such as vemurafenib have emerged as a promising option for patients as seen in both scientific and clinical research. Furthermore, combination therapies are starting to be administered in the form of polychemotherapy, polyimmunotherapy, and biochemotherapy, of which some have shown promising outcomes in relative efficacy and safety due to their multiple targets. Alongside these treatments, new research has been conducted into the evidence-based use of natural health products (NHPs) and natural compounds (NCs) on melanoma which may provide a long-term and non-toxic form of complementary therapy. Nevertheless, there is a limited consolidation of the research conducted in emerging melanoma treatments which may be useful for researchers and clinicians. Thus, this review attempts to evaluate the therapeutic efficacy of current advancements in metastatic melanoma treatment by surveying new research into the molecular and cellular basis of treatments along with their clinical efficacy. In addition, this review aims to elucidate novel strategies that are currently being used and have the potential to be used in the future.

The application of nanoparticles in cancer immunotherapy: Targeting tumor microenvironment

The tumor development and metastasis are closely related to the structure and function of the tumor microenvironment (TME). Recently, TME modulation strategies have attracted much attention in cancer immunotherapy. Despite the preliminary success of immunotherapeutic agents, their therapeutic effects have been restricted by the limited retention time of drugs in TME. Compared with traditional delivery systems, nanoparticles with unique physical properties and elaborate design can efficiently penetrate TME and specifically deliver to the major components in TME. In this review, we briefly introduce the substitutes of TME including dendritic cells, macrophages, fibroblasts, tumor vasculature, tumor-draining lymph nodes and hypoxic state, then review various nanoparticles targeting these components and their applications in tumor therapy. In addition, nanoparticles could be combined with other therapies, including chemotherapy, radiotherapy, and photodynamic therapy, however, the nanoplatform delivery system may not be effective in all types of tumors due to the heterogeneity of different tumors and individuals. The changes of TME at various stages during tumor development are required to be further elucidated so that more individualized nanoplatforms could be designed.

How I Treat Non-Small Cell Lung Cancer Refractory to Immunotherapy

Lung cancer is a leading cause of cancer-related mortality despite continued advances in diagnostic and therapeutic strategies. Although the development of immune checkpoint inhibitors has revolutionized the treatment landscape for advanced non-small cell lung cancer, many patients either have primary resistance to these agents or eventually develop secondary resistance necessitating a change to an alternate therapy. Understanding novel patterns of response to immunotherapy is crucial in determining appropriate selection and sequencing of treatment. Chemotherapy remains the standard of care in immunotherapy-refractory disease, but multiple trials are ongoing to explore the role of combination radioimmunotherapy and rechallenging with immunotherapy either alone or in combination with other antineoplastic agents.

Retreatment with immune checkpoint inhibitors in solid tumors: a systematic review

BACKGROUND

A large proportion of patients eventually experience disease progression despite treatment with immune checkpoint inhibitors (ICIs), but subsequent treatment options are limited for this population. Retreatment with the same or different types of ICIs is a possible strategy, but the clinical efficacy and safety data are limited. This systematic review aims to evaluate the efficacy and safety of ICIs retreatment in patients with solid tumors after disease progression to previous ICIs.

METHODS

We searched MEDLINE, EMBASE, the Cochrane Library, and major meeting libraries for prospective studies. The primary outcomes included the objective response rate (ORR), disease control rate (DCR), median overall survival (mOS), and the incidence of grade ⩾3 immune-related adverse events (irAEs).

RESULTS

We identified 22 prospective studies including 1865 patients. For disease progression after CTLA-4 inhibitors, three studies evaluated anti-CTLA-4 retreatment. The ORR was 12-23%, the DCR was 48.4-67.7%, and the mOS was 12 months. The incidence of grade ⩾3 irAEs was 5.9-25%. Four studies evaluated anti-programmed cell death protein 1 (PD-1) retreatment. The ORR was 22-36%, the DCR was 40-64%, and the mOS was 13.4-20.6 months. The incidence of grade ⩾3 irAEs was <10%. For disease progression after PD-(L)1 inhibitors, 13 studies evaluated anti-PD-(L)1 retreatment. The ORR was 5-53%, the DCR was 38-83%, and the mOS was 13.9 months. The incidence of grade ⩾3 irAEs was 0-15% for patients retreated with single anti-PD-(L)1 agent, but was higher (0-64%) for those retreated with ICIs combined with other agents. Two studies evaluated anti-cytotoxic T-lymphocyte associated protein 4 (CTLA-4) retreatment. The ORR was 0-22.4%, the DCR was 50-72%, and the mOS was 4-21 months. The incidence of grade ⩾3 irAEs was 26-61%.

CONCLUSION

Retreatment with ICIs is feasible for cancer patients considering its encouraging efficacy and tolerable safety. Further prospective trials are needed to explore more promising strategies and identify suitable populations for retreatment.

Polyphenol-Based Nanomedicine Evokes Immune Activation for Combination Cancer Treatment

Engineering multifunctional nanoplatforms with high therapeutic benefits has become a promising strategy for intractable cancer treatment. A novel polyphenol-based nanocomplex was designed to evoke highly efficacious cancer immunosurveillance while localizing therapy on the primary tumor and to minimize systemic side effects. This nanocomplex is prepared via metal-polyphenol coordination by encapsulating a natural polyphenol, gossypol, and a newly synthesized polyphenol derivative, polyethylene glycol-Chlorin e6 (Ce6). The combination of gossypol from cotton and the photosensitizer Ce6 can induce chemotherapeutic/photodynamic immunogenic cancer cell death upon laser irradiation, which is supported by a rich maturation of dendritic cells, concentrated secretion of inflammatory cytokines, and significant inhibition of distant untreated tumors. Finally, an assistance of the programmed-cell-death ligand-1 checkpoint-blockade immunotherapy can enhance the anti-tumor immune stimulation of our nanoplatform to a higher level.

Rechallenge of anti-PD-1/PD-L1 antibody showed a good response to metastatic breast cancer: a case report

Rechallenge of immune checkpoint inhibitors has been reported for neoplasms other than breast cancer. Reported here is a case of a 55-year old woman diagnosed as having triple-negative right breast cancer with multiple metastases including lung. Atezolizumab and nab-paclitaxel were administered followed by epirubicin-cyclophosphamide. With subsequent eribulin, the overall best response was progressive disease, and curative surgical resection was performed. Three months after surgery (1.5 years after initial response of lung metastasis), right lung metastasis emerged at a site different from baseline. Based on the microsatellite instability-high status, pembrolizumab was administered and showed a good response. The patient has been treated with pembrolizumab, maintaining partial response, for over 9 months, which suggests the benefit of immune checkpoint inhibitors rechallenge in breast cancer.

Retreatment with talimogene laherparepvec for advanced melanoma

Aim: Talimogene laherparepvec (T-VEC) is a genetically modified oncolytic herpesvirus approved for the treatment of unresectable, locoregionally advanced and recurrent melanoma. There is little relevant literature in the context of retreatment with T-VEC. Materials & methods: We reviewed four patients aged 71-87 years old with stage IIIB-IV melanoma at treatment who were rechallenged with T-VEC after experiencing recurrence of locoregional disease or prior treatment-limiting toxicity. Results: Cessation of initial treatment was due to one of the following reasons: severe adverse event (one case), mixed response (one case) or complete response (two cases). Three males and one female underwent T-VEC retreatment with a mean of 5.5 injection cycles. Three patients experienced a complete response to retreatment, while one experienced disease progression. Conclusion: Intralesional T-VEC may be effective and well-tolerated in patients who have completed prior T-VEC therapy.

Safety of pembrolizumab for resected stage III melanoma

INTRODUCTION

Patients with resected stage III melanoma have a heterogeneous prognosis with an especially high risk of relapse for patients with stage IIIB, IIIC and IIID according to the 2018 classification in AJCC Cancer Staging Manual, 8^th edition (AJCC-8). Ipilimumab was the first immune checkpoint inhibitor (ICI) to show prolonged overall survival (OS) but at the cost of high toxicity. Pembrolizumab and nivolumab are inhibitors of programmed cell death 1 (PD-1) and showed prolonged relapse-free survival (RFS) in patients with resected stage III melanoma at high risk of relapse compared to placebo and ipilimumab, respectively.

AREAS COVERED

The aim of this article is to review the mechanisms of action, pharmacokinetics and safety data of pembrolizumab in resected stage III melanoma and to compare its safety profile to other immune checkpoint inhibitors for the same indication.

EXPERT OPINION

Pembrolizumab as adjuvant therapy of resected stage III melanoma showed an acceptable safety profile, which is comparable to that in advanced melanoma. However, it caused one death. There is uncertainty about its benefits in AJCC-8 stage IIIA melanoma patients. Additionally, caution is required since OS and long-term safety data are not available yet.

Durvalumab activity in previously treated patients who stopped durvalumab without disease progression

BACKGROUND

Limited data exist on potential clinical benefit with anti-programmed cell death ligand-1 (PD-L1) retreatment in patients who stop initial therapy for reasons other than disease progression or toxicity and develop disease progression while off treatment.

PATIENTS AND METHODS

NCT01693562 was a phase I/II study evaluating durvalumab monotherapy in advanced solid tumors. Patients benefiting from treatment were taken off durvalumab at 1 year per protocol and prospectively followed. At disease progression, they were eligible for durvalumab retreatment. Outcomes evaluated during retreatment included best overall response (BOR2), duration of response (DoR2), disease control rate (DCR2), and progression-free survival (PFS2).

RESULTS

Of 980 patients enrolled and treated with durvalumab 10 mg/kg every 2 weeks (Q2W) in the dose-expansion cohorts, 168 completed 1 year of initial durvalumab treatment with confirmed BOR1 of complete response in 20 (11.9%), partial response (PR) in 84 (50%), stable disease (SD) in 52 (31%), and disease progression in 12 (7.1%). All 168 patients stopped treatment and were eligible for retreatment at progression; 70 patients (41.7%) representing 14 primary tumor types were retreated and response evaluable. Confirmed BOR2 was PR in 8 patients (11.4%), SD in 42 (60.0%), disease progression in 16 (22.9%), and unevaluable in 4 (5.7%). Median DoR2 was 16.5 months. DCR2 ≥24 weeks (DCR2 24) was 47.1%. PFS2 rate at 12 months was 34.2%, and median PFS2 was 5.9 months. Median overall survival (OS2) was 23.8 months. Response rates, DCR2 24, and median DoR2 were generally greater in patients with high PD-L1 expression than those with low/negative expression. No new safety signals were observed during retreatment.

CONCLUSION

Retreatment restored antitumor activity, resulting in high rates of durable disease control with an acceptable safety profile. This evidence supports retreatment of patients who stop anti-PD-L1 therapy for reasons other than progression or toxicity, and supports further investigation.

When is it OK to Stop Anti-Programmed Death 1 Receptor (PD-1) Therapy in Metastatic Melanoma?

Systemic therapy for metastatic melanoma has been revolutionized over the past decade with the development of highly effective immune checkpoint inhibition, specifically anti-Programmed Death 1 receptor (PD-1) therapy. However, even though one-third of patients will have durable response to single-agent or combination therapy, the optimal duration of therapy is unknown. Identifying the optimal duration of therapy is important, as exposure to anti-PD-1 therapy increases the risk of developing immune-mediated toxicities that can have significant morbidity and are, at times, fatal. It has long been understood that patients with complete responses to high-dose interleukin-2 and ipilimumab typically maintain their responses after a brief treatment course; thus, it is important to better understand the data to help understand the optimal management of melanoma patients treated with anti-PD-1 therapy. The clinical data with anti-PD-1-based therapy and published data on the duration of therapy suggest that patients may not require a full 2 years of anti-PD-1 therapy and that the risk of toxicity may be mitigated by further understanding the mechanisms and kinetics of response to therapy. Although novel markers to help guide therapeutic decision making are under investigation, there is an ongoing need to improve our tools to monitor response to therapy and disease activity.