Biomarkers of response to immune checkpoint blockade in cancer treatment

Innovative Drug Modalities for the Treatment of Advanced Prostate Cancer

Prostate cancer, a prevalent malignancy affecting the prostate gland, is a significant global health concern. Androgen-deprivation therapy (ADT) has proven effective in controlling advanced disease, with over 50% of patients surviving at the 10-year mark. However, a diverse spectrum of responses exists, and resistance to ADT may emerge over time. This underscores the need to explore innovative treatment strategies for effectively managing prostate cancer progression. Ongoing research endeavors persist in unraveling the complexity of prostate cancer and fostering the development of biologic and innovative approaches, including immunotherapies and targeted therapies. This review aims to provide a valuable synthesis of the dynamic landscape of emerging drug modalities in this context. Interestingly, the complexities posed by prostate cancer not only present a formidable challenge but also serve as a model and an opportunity for translational research and innovative therapies in the field of oncology.

The use of pembrolizumab monotherapy for the management of head and neck squamous cell carcinoma (HNSCC) in the UK

Pembrolizumab has received approval in the UK as first-line monotherapy for recurrent and/or metastatic HNSCC (R/M HNSCC) following the results of the KEYNOTE-048 trial, which demonstrated a longer overall survival (OS) in comparison to the EXTREME chemotherapy regimen in patients with a combined positive score (CPS) ≥1. In this article, we provide retrospective real-world data on the role of pembrolizumab monotherapy as first-line systemic therapy for HNSCC across 18 centers in the UK from March 20, 2020 to May 31, 2021. 211 patients were included, and in the efficacy analysis, the objective response rate (ORR) was 24.7%, the median progression-free survival (PFS) was 4.8 months (95% confidence interval [CI]: 3.6-6.1), and the median OS was 10.8 months (95% CI 9.0-12.5). Pembrolizumab monotherapy was well tolerated, with 18 patients having to stop treatment owing to immune-related adverse events (irAEs). 53 patients proceeded to second-line treatment with a median PFS2 of 10.2 months (95% CI: 8.8-11.5). Moreover, patients with documented irAEs had a statistically significant longer median PFS (11.3 vs. 3.3 months; log-rank p value = <.001) and median OS (18.8 vs. 8.9 months; log-rank p value <.001). The efficacy and safety of pembrolizumab first-line monotherapy for HNSCC has been validated using real-world data.

A Phase II Clinical Trial of Pembrolizumab Efficacy and Safety in Advanced Renal Medullary Carcinoma

BACKGROUND

Renal medullary carcinoma (RMC) is one of most aggressive renal cell carcinomas and novel therapeutic strategies are therefore needed. Recent comprehensive molecular and immune profiling of RMC tissues revealed a highly inflamed phenotype, suggesting the potential therapeutic role for immune checkpoint therapies. We present the first prospective evaluation of an immune checkpoint inhibitor in a cohort of patients with RMC.

METHODS

A cohort of patients with locally advanced or metastatic RMC was treated with pembrolizumab 200 mg intravenously every 21 days in a phase II basket trial (ClinicalTrials.gov: NCT02721732). Responses were assessed by irRECIST. Tumor tissues were evaluated for PD-L1 expression and for tumor-infiltrating lymphocyte (TIL) levels. Somatic mutations were assessed by targeted next-generation sequencing.

RESULTS

A total of five patients were treated. All patients had advanced disease, with the majority of patients (60%) having metastatic disease at diagnosis. All patients had rapid disease progression despite pembrolizumab treatment, with a median time to progression of 8.7 weeks. One patient (patient 5) experienced sudden clinical progression immediately after treatment initiation and was thus taken off trial less than one week after receiving pembrolizumab.

CONCLUSIONS

This prospective evaluation showed no evidence of clinical activity for pembrolizumab in patients with RMC, irrespective of PD-L1 or TIL levels.

Metastatic Castration-Resistant Prostate Cancer: Insights on Current Therapy and Promising Experimental Drugs

The therapeutic landscape of metastatic hormone sensitive and metastatic castration-resistant prostate cancer (mCRPC) is rapidly changing. We reviewed the current treatment options for mCRPC, with insights on new available therapeutic strategies. Chemotherapy with docetaxel or cabazitaxel (for patients progressing on docetaxel), as well as treatment with androgen receptor axis targeted therapies, and Radium-223 are well-established treatment options for patients with mCRPC. The advent of theragnostic in prostate cancer established Lutetium-177 (177Lu)-PSMA-617 as a new standard of care for PSMA-positive mCRPC previously treated with ARAT and taxane-based chemotherapy. Olaparib, a poly-ADP-ribose polymerase (PARP) inhibitor, is approved for selected patients with mCRPC progressed on ARATs and in combination with abiraterone acetate as first-line treatment for mCRPC. Immunotherapy showed limited efficacy in unselected patients with mCRPC and novel immunotherapy strategies need to be explored. The search for biomarkers is a growing field of interest in mCRPC, and predictive biomarkers are needed to support the choice of treatment and the development of tailored strategies.

Applications and clinical trial landscape using Toll-like receptor agonists to reduce the toll of cancer

Toll-like receptors (TLRs), which serve as a bridge between innate and adaptive immunity, may be viable treatment targets. TLRs are the first line of defense against microbes and activate signaling cascades that induce immune and inflammatory responses. Patients with "hot" versus "cold" tumors may respond more favorably to immune checkpoint inhibition, and through their downstream effects, TLR agonists have the potential to convert "cold tumors" into "hot tumors" making TLRs in combination with immune checkpoint inhibitors, potential targets for cancer therapies. Imiquimod is a topical TLR7 agonist, approved by the FDA for antiviral and skin cancer treatments. Other TLR adjuvants are used in several vaccines including Nu Thrax, Heplisav, T-VEC, and Cervarix. Many TLR agonists are currently in development as both monotherapy and in combination with immune checkpoint inhibitors. In this review, we describe the TLR agonists that are being evaluated clinically as new therapies for solid tumors.

PD-L1 gene amplification and focality: relationship with protein expression

PD-L1 (CD274) amplification occurs in a small subset of malignancies and may predict anti-PD-1/PD-L1 immunotherapy responsiveness. We hypothesized that both copy number (CN) and focality of cancer-related PD-L1 amplifications impact protein expression, and, thus, analyzed solid tumors that underwent comprehensive genomic profiling between March 2016 and February 2022 at Foundation Medicine. PD-L1 CN alterations were detected using a comparative genomic hybridization-like method. PD-L1 CN changes were correlated with PD-L1 protein expression (DAKO 22C3 antibody) by immunohistochemistry (IHC). Overall, 60,793 samples were analyzed (most frequent histologies: lung adenocarcinoma (20%), colon adenocarcinoma (12%), lung squamous carcinoma (8%)). Using a definition of CD274 CN ≥ specimen ploidy +4 (6 copies), 1.21% of tumors (738/60,793) were PD-L1 amplified. Focality category distribution was as follows: <0.1 mB (n=18 (2.4%)), ≥0.1 to <4 mB (n=230 (31.1%)), ≥4 to <20 mB (n=310 (42%)), ≥20mB (n=180 (24.4%)). Lower levels of PD-L1 amplification (below specimen ploidy +4) were more frequently non-focal amplifications compared to higher levels. In addition, more focal amplification (<0.1 mB) correlated with higher PD-L1 IHC expression. Median tumor proportion score (TPS) for samples with PD-L1 amplification (ploidy ≥+4) according to focality were 87.5% (<0.1 mB), 80% (≥0.1 to <4 mB), 40% (≥4 to <20 mB), 1% (≥20mB). In specimens with PD-L1 ploidy less than +4, but highly focal (<0.1 mB), the 75th percentile of PD-L1 expression by TPS was 80%. Conversely, non-focal (≥20 mB) PD-L1 amplification (ploidy ≥+4) can present high PD-L1 expression (TPS≥50%), albeit infrequently (0.09% of our cohort). In conclusion, PD-L1 expression measured by IHC is influenced by PD-L1 amplification level and focality. Further correlation between amplification, focality, protein expression and therapeutic outcome for PD-L1 and other targetable genes warrants exploration.

Total serum N-glycans associate with response to immune checkpoint inhibition therapy and survival in patients with advanced melanoma

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of melanoma and other cancers. However, no reliable biomarker of survival or response has entered the clinic to identify those patients with melanoma who are most likely to benefit from ICIs. Glycosylation affects proteins and lipids' structure and functions. Tumours are characterized by aberrant glycosylation which may contribute to their progression and hinder an effective antitumour immune response.

METHODS

We aim at identifying novel glyco-markers of response and survival by leveraging the N-glycome of total serum proteins collected in 88 ICI-naive patients with advanced melanoma from two European countries. Samples were collected before and during ICI treatment.

RESULTS

We observe that responders to ICIs present with a pre-treatment N-glycome profile significantly shifted towards higher abundancy of low-branched structures containing lower abundances of antennary fucose, and that this profile is positively associated with survival and a better predictor of response than clinical variables alone.

CONCLUSION

While changes in serum protein glycosylation have been previously implicated in a pro-metastatic melanoma behaviour, we show here that they are also associated with response to ICI, opening new avenues for the stratification of patients and the design of adjunct therapies aiming at improving immune response.

Caspase-8 contributes to an immuno-hot microenvironment by promoting phagocytosis via an ecto-calreticulin-dependent mechanism

BACKGROUND

Caspase-8 (Casp8) acts as an initiator in cell apoptosis signaling. However, the role of Casp8 in tuning the tumor immune microenvironment remains controversial due to the complicated crosstalk between immune-tolerogenic apoptotic cell death and immunogenic cell death cascades.

METHODS

The Cancer Genome Atlas (TCGA) and publicly accessible immune checkpoint blockade (ICB)-treated cohorts were used to investigate the clinical relevance of Casp8. A tumor-bearing mouse model was used to characterize changes in the tumor microenvironment and to explore the efficacy of ICB treatment under Casp8 knockout conditions.

RESULTS

By exploring TCGA datasets, we showed that the expression level of Casp8 was associated with an immuno-hot microenvironment across various solid tumor types. Casp8 deficiency leads to decreased CD8⁺ T cell infiltration and resistance to anti-PD-L1 therapy in a mouse model. Mechanistically, Casp8 deficiency or pharmacological disruption results in impaired ecto-calreticulin transition in tumor cells, which in turn hampers antigen presentation in draining lymph nodes. Furthermore, radiotherapy restored sensitivity to anti-PD-L1 treatment via elevated calreticulin surface expression.

CONCLUSIONS

Our data revealed a causative role of Casp8 in modulating the immunogenicity of tumor cells and responsiveness to ICB immunotherapies and proposed radiotherapy as a salvage approach to overcome Casp8 deficiency-mediated ICB resistance.

Efficacy and Safety of Atezolizumab Monotherapy or Combined Therapy with Chemotherapy in Patients with Metastatic Triple-negative Breast Cancer: A Systematic Review and Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Several successful attempts have been recorded with PD-L1 blockade via atezolizumab monotherapy or combination therapy with chemotherapy in patients with metastatic triple-negative breast cancer (mTNBC). Due to the lack of a large-scale study, we present a meta-analysis aimed at evaluating the safety and efficacy of this promising strategy in patients with mTNBC.

METHODS

A comprehensive literature search was conducted using electronic databases to identify eligible RCTs. Twelve studies, including 2479 mTBNC patients treated with atezolizumab monotherapy or in combination with chemotherapy, were included up to January 2022. The PRISMA checklist protocol and the I2 statistic were applied for quality assessment and heterogeneity tests of the selected trials, respectively. Fixed and random-effects models were estimated based on the heterogeneity tests, and statistical analysis was performed using CMA.

RESULTS

Our pooled findings demonstrated that the median overall survival (OS) and progression-free survival (PFS) were 16.526 and 5.814 months in mTNBC patients, respectively. Furthermore, when comparing efficacy indicators between PD-L1-positive and PD-L1-negative groups, mTNBC patients with PD-L1 had better OS, PFS, and ORR than PD-L1-negative patients. Also, the immune-related adverse event incident for alopecia was higher (51.9%) than other complications across atezolizumab therapy.

CONCLUSION

Moreover, the pooled analysis indicated that the overall rate of lung metastasis following atezolizumab therapy was 42.8%, which was higher than the rates of metastasis in bone (26.9%), brain (5.4%), and lymph node (6.5%). Atezolizumab showed a manageable safety profile and had promising and durable anti-tumor efficacy in TMBC patients. Higher PD-L1 expression may be closely correlated with better clinical efficacy.

Dendritic Cells: The Long and Evolving Road towards Successful Targetability in Cancer

Dendritic cells (DCs) are a unique myeloid cell lineage that play a central role in the priming of the adaptive immune response. As such, they are an attractive target for immune oncology based therapeutic approaches. However, targeting these cells has proven challenging with many studies proving inconclusive or of no benefit in a clinical trial setting. In this review, we highlight the known and unknown about this rare but powerful immune cell. As technologies have expanded our understanding of the complexity of DC development, subsets and response features, we are now left to apply this knowledge to the design of new therapeutic strategies in cancer. We propose that utilization of these technologies through a multiomics approach will allow for an improved directed targeting of DCs in a clinical trial setting. In addition, the DC research community should consider a consensus on subset nomenclature to distinguish new subsets from functional or phenotypic changes in response to their environment.

The role of gut microbiome in immune modulation in metastatic renal cell carcinoma

Treatment of metastatic renal cell carcinomas (mRCC) has drastically improved since the advent of immunotherapy with immune checkpoint inhibitors (ICIs), with a significant proportion of patients achieving durable responses. While this has revolutionized treatment and improved outcomes for mRCC patients, a large subset of patients still does not respond to treatment with ICIs. Moreover, ICIs can induce various immune-related adverse events, limiting their use in many patients. Therefore, there is a need to identify the predictive biomarkers of both efficacy and toxicity associated with ICIs, which would allow for a more personalized approach and help with clinical decision-making. This review aims to explore the role of the gut microbiome in RCC to overcome primary resistance and predict response to treatment with ICIs. First, current therapeutic strategies and mechanisms of action of ICI therapies for RCC treatment will be reviewed. With the technological development of shotgun whole-genome sequencing, the gut microbiome has emerged as an exciting field of research within oncology. Thus, the role of the microbiome and its bidirectional interaction with ICIs and other drugs will be explored, with a particular focus on the microbiome profile in RCC. Lastly, the rationale for future clinical interventions to overcome resistance to ICIs using fecal microbiota transplantation in patients with RCC will be presented.

Miniaturized and multiplexed high-content screening of drug and immune sensitivity in a multichambered microwell chip

Here, we present a methodology based on multiplexed fluorescence screening of two- or three-dimensional cell cultures in a newly designed multichambered microwell chip, allowing direct assessment of drug or immune cell cytotoxic efficacy. We establish a framework for cell culture, formation of tumor spheroids, fluorescence labeling, and imaging of fixed or live cells at various magnifications directly in the chip together with data analysis and interpretation. The methodology is demonstrated by drug cytotoxicity screening using ovarian and non-small cell lung cancer cells and by cellular cytotoxicity screening targeting tumor spheroids of renal carcinoma and ovarian carcinoma with natural killer cells from healthy donors. The miniaturized format allowing long-term cell culture, efficient screening, and high-quality imaging of small sample volumes makes this methodology promising for individualized cytotoxicity tests for precision medicine.

Emerging Biomarker-Guided Therapies in Prostate Cancer

Prostate cancer remains one of the leading causes of cancer death in men worldwide. In the past decade, several new treatments for advanced prostate cancer have been approved. With a wide variety of available drugs, including cytotoxic agents, androgen receptor axis-targeted therapies, and alpha-emitting radiation therapy, identifying their optimal sequencing remains a challenge. Progress in the understanding of the biology of prostate cancer has provided an opportunity for a more refined and personalized treatment selection process. With the advancement of molecular sequencing techniques, genomic precision through the identification of potential treatment targets and predictive biomarkers has been rapidly evolving. In this review, we discussed biomarker-driven treatments for advanced prostate cancer. First, we presented predictive biomarkers for established, global standard treatments for advanced diseases, such as chemotherapy and androgen receptor axis-targeted agents. We also discussed targeted agents with recent approval for special populations, such as poly ADP ribose polymerase (PARP) inhibitors in patients with metastatic castrate-resistant prostate cancer with homologous recombination repair-deficient tumors, pembrolizumab in patients with high levels of microsatellite instability or high tumor mutational burden, and prostate-specific membrane antigen (PSMA) directed radioligand theragnostic treatment for PSMA expressing tumors. Additionally, we discussed evolving treatments, such as cancer vaccines, chimeric antigen receptor T-cells (CAR-T), Bispecific T-cell engagers (BiTEs), other targeted agents such as AKT inhibitors, and various combination treatments. In summary, advances in molecular genetics have begun to propel personalized medicine forward in the management of advanced prostate cancer, allowing for a more precise, biomarker-driven treatment selection with the goal of improving overall efficacy.

Plasma Thymidine Kinase Activity as a Novel Biomarker in Metastatic Melanoma Patients Treated with Immune Checkpoint Inhibitors

Simple Summary

Immune checkpoint inhibitors (ICI) are effective in fractions of patients with disseminated melanoma. Significant toxicity can also occur from the treatments, that, in addition, are expensive. It is therefore important to increase the knowledge of predictive factors and their efficacy in different patient groups. This study is the first to analyze the plasma activity of thymidine kinase (TK), an enzyme involved in DNA synthesis and repair, as a biomarker in melanoma patients. In this study, high TK activity (TKa) levels in melanoma patients were associated with poor baseline factors, such as poor performance status, high plasma lactate dehydrogenase levels, and advanced tumor stage. High TKa levels were also associated with a poor efficacy of immune checkpoint inhibitors. TKa is hence a novel and interesting plasma biomarker in melanoma and should be further studied to define its role as a prognostic and predictive marker in this disease.

Abstract

Background. Immune checkpoint inhibitors (ICI) are effective in fractions of patients with disseminated melanoma. This study is the first to analyze the plasma activity of thymidine kinase (TK), an enzyme involved in DNA synthesis and repair, as a biomarker in melanoma patients. Methods. Plasma samples were collected prior to treatment start in patients with unresectable metastatic cutaneous melanoma, treated with ICI (anti-CTLA-4 and/or anti-PD-1). Plasma TK activity (TKa) levels were determined using the DiviTum TKa ELISA assay. TKa levels were correlated with patients’ baseline characteristics, response rate (RR), progression-free survival (PFS), and overall survival (OS). Results. In the 90 study patients, the median TKa level was 42 Du/L (range <20–1787 Du/L). A significantly higher plasma TKa was found in patients with ECOG performance status ≥1 (p = 0.003), M1c-d disease (p = 0.015), and elevated lactate dehydrogenase levels (p < 0.001). The RR was 63.2% and 30.3% in those with low or high TKa, respectively (p = 0.022). The median PFS was 19.9 and 12.6 months in patients with low or high TKa, respectively (hazard ratio (HR) 1.83 (95% CI, 1.08–3.08), p = 0.024). The median OS was >60 months and 18.5 months in patients with low or high TKa, respectively (HR: 2.25 (95% CI, 1.25–4.05), p = 0.011. Conclusions. High pretreatment plasma TKa levels were significantly associated with worse baseline characteristics and poor response and survival in ICI-treated melanoma patients. TKa is hence a novel and interesting plasma biomarker in melanoma and should be further studied to define its role as a prognostic and predictive marker in this disease.

Associations between immune-related thyroid dysfunction and efficacy of immune checkpoint inhibitors: a systematic review and meta-analysis

BACKGROUND

There is growing evidence suggesting that the occurrence of immune-related adverse events (irAEs) may be a predictor of immune checkpoint inhibitor efficacy. Whether this association extends to all irAEs or just those within particular organs/systems is yet to be resolved. As immune-related thyroid dysfunction (thyroid irAE) is one of the most commonly reported irAEs, this study aims to summarize the available data and determine if thyroid irAE is a surrogate marker for improved cancer outcomes during ICI therapy.

METHODS

PubMed, EMBASE and Cochrane Library were searched up to July 1st 2021 for studies assessing the relationship between thyroid irAE development during ICI therapy and cancer outcomes. Outcome measures of interest include overall survival (OS) and progression free survival (PFS). Sub-group analyses based on cancer type and adjustment for immortal time bias (ITB) were also performed.

RESULTS

Forty-seven studies were included in the systematic review. Twenty-one studies were included in the OS meta-analysis whilst 15 were included in the PFS meta-analysis. Development of thyroid irAE during ICI therapy was associated with improved OS and PFS (OS: HR 0.52, CI 0.43-0.62, p < 0.001; PFS: HR 0.58, CI 0.50-0.67, p < 0.001). Sub-group analyses involving non-small cell lung cancer populations and studies where ITB was accounted for, observed similar results (HR 0.37, CI 0.24-0.57, p < 0.001) and (HR 0.51, CI 0.39-0.69, p < 0.001), respectively.

CONCLUSION

Despite the heterogeneity and biases identified, the evidence does suggest that the development of thyroid irAE is associated with anti-tumor effects of ICIs and therefore, can be used as a surrogate marker for clinical response.

An Update on Immune Based Therapies in Acute Myeloid Leukemia: 2021 and Beyond!

Despite advances in the treatment of acute myeloid leukemia (AML), relapse is still widely observed and represents the major cause of death among patients with AML. Treatment options in the relapse setting are limited, still relying predominantly on allogeneic hematopoietic stem cell transplantation (allo-HSCT) and cytotoxic chemotherapy, with poor outcomes. Novel targeted and venetoclax-based combinations are being investigated and have shown encouraging results. Immune checkpoint inhibitors in combination with low-intensity chemotherapy demonstrated encouraging response rates and survival among patients with relapsed and/or refractory (R/R) AML, especially in the pre- and post-allo-HSCT setting. Blocking the CD47/SIRPα pathway is another strategy that showed robust anti-leukemic activity, with a response rate of around 70% and an encouraging median overall survival in patients with newly diagnosed, higher-risk myelodysplastic syndrome and patients with AML with a TP53 mutation. One approach that was proven to be very effective in the relapsed setting of lymphoid malignancies is chimeric antigen receptor (CAR) T cells. It relies on the infusion of genetically engineered T cells capable of recognizing specific epitopes on the surface of leukemia cells. In AML, different CAR constructs with different target antigens have been evaluated and demonstrated safety and feasibility in the R/R setting. However, the difficulty of potently targeting leukemic blasts in AML while sparing normal cells represents a major limitation to their use, and strategies are being tested to overcome this obstacle. A different approach is based on endogenously redirecting the patient's system cells to target and destroy leukemic cells via bispecific T-cell engagers (BiTEs) or dual antigen receptor targeting (DARTs). Early results have demonstrated the safety and feasibility of these agents, and research is ongoing to develop BiTEs with longer half-life, allowing for less frequent administration schedules and developing them in earlier and lower disease burden settings.

Immune-Related Oral, Otologic, and Ocular Adverse Events

Emerging immunotherapeutic agents, including immune checkpoint inhibitors targeting cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed cell death protein ligand 1 (PD-L1), have revolutionized cancer treatment. The first immune checkpoint inhibitor (ICI) ipilimumab, an anti-CTLA-4, was approved in 2011. Since then, the US Food and Drug Administration (FDA) has approved more than half a dozen immune checkpoint inhibitors to treat various malignancies. These agents are part of a broader class of chemotherapy agents termed immunotherapy, which selectively target different steps in the immune response cascade to upregulate the body's normal response to cancer. While the effects of traditional chemotherapy are well known, the toxicity profile of emerging immune therapies is not fully elucidated. They have been associated with atypical side effects labeled collectively as immune-related adverse events (irAEs).

Immunotherapy in Lung Cancer: Are the Promises of Long-Term Benefit Finally Met?

Over the last few years, agents targeting immune checkpoints have shown potential to improve therapeutic outcomes in patients with lung cancer in multiple clinical settings. Inhibitors of PD-1/PD-L1 have been approved for the treatment of different types of lung cancer by the FDA either alone or in combination with chemotherapy or other immune checkpoint inhibitors, such as anti-CTLA-4 agents. The introduction of these agents in clinical practice has revolutionized the therapeutic approach to lung cancer, keeping the promises of long-term benefit in selected patient populations. The therapeutic indications of immunotherapy in lung cancer are rapidly growing, and multiple combinations entered clinical practice or are under active development. Furthermore, the quest for a reliable predictive biomarker is still ongoing to overcome the limits of currently approved tests for patients' selection. In this review, we summarized the current status and progress of anti-PD-1/PD-L1 agents in lung cancer treatment.

Neurologic Toxicities of Immunotherapy

Immunotherapy has revolutionized treatment of cancer over the past two decades. The antitumor effects of immunotherapy approaches are at the expense of growing spectrum of immune-related adverse events (irAEs) due to cross-reactivity between the tumor and normal host tissue. These adverse events can happen in any organ and range from mild to severe and even life-threatening conditions. While neurological irAEs associated with immune checkpoint inhibitors (CPIs) are rare, they pose a significant challenge in management as the clinical phenotypes are heterogenous and frequently necessitate cessation of therapy and systemic immune suppression and lead to transient functional decline. On the other hand, immune effector cell-associated neurotoxicity (ICANS) is common, frequently occurs in conjunction with cytokine release syndrome (CRS), and poses a significant clinical challenge to the development and widespread use of these effective therapies. Early recognition of these neurological syndromes, timely diagnosis, and thoughtful management are key for further clinical development of these effective therapies in cancer patients. Here, we describe clinical phenotypes of CPI-induced neurological complications and ICANS and discuss steps in clinical monitoring, diagnosis, and effective management.

A Pan-Cancer Analysis of Predictive Methylation Signatures of Response to Cancer Immunotherapy

Recently, tumor immunotherapy based on immune checkpoint inhibitors (ICI) has been introduced and widely adopted for various tumor types. Nevertheless, tumor immunotherapy has a few drawbacks, including significant uncertainty of outcome, the possibility of severe immune-related adverse events for patients receiving such treatments, and the lack of effective biomarkers to determine the ICI treatments' responsiveness. DNA methylation profiles were recently identified as an indicator of the tumor immune microenvironment. They serve as a potential hot spot for predicting responses to ICI treatment for their stability and convenience of measurement by liquid biopsy. We demonstrated the possibility of DNA methylation profiles as a predictor for responses to the ICI treatments at the pan-cancer level by analyzing DNA methylation profiles considered responsive and non-responsive to the treatments. An SVM model was built based on this differential analysis in the pan-cancer levels. The performance of the model was then assessed both at the pan-cancer level and in specific tumor types. It was also compared to the existing gene expression profile-based method. DNA methylation profiles were shown to be predictable for the responses to the ICI treatments in the TCGA cases in pan-cancer levels. The proposed SVM model was shown to have high performance in pan-cancer and specific cancer types. This performance was comparable to that of gene expression profile-based one. The combination of the two models had even higher performance, indicating the potential complementarity of the DNA methylation and gene expression profiles in the prediction of ICI treatment responses.

Pretreatment clinical and hematologic prognostic factors of metastatic urothelial carcinoma treated with pembrolizumab: a systematic review and meta-analysis

Pembrolizumab is the standard for the first and second lines in treating metastatic urothelial carcinoma (UC). This systematic review and meta-analysis aimed to assess the value of pretreatment clinical characteristics and hematologic biomarkers for prognosticating response to pembrolizumab in patients with metastatic UC. PUBMED^®, Web of Science™, and Scopus^® databases were searched for articles published before May 2021 according to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) statement. Studies were deemed eligible if they evaluated overall survival (OS) in patients with metastatic urothelial carcinoma treated with pembrolizumab and pretreatment clinical characteristics or laboratory examination. Overall, 13 studies comprising 1311 patients were eligible for the meta-analysis. Several pretreatment patients’ demographics and hematologic biomarkers were significantly associated with worse OS as follows: Eastern Cooperative Oncology Group Performance Status (ECOG-PS) ≥ 2 (Pooled hazard ratio [HR]: 3.24, 95% confidence interval [CI] 2.57–4.09), presence of visceral metastasis (Pooled HR: 1.84, 95% CI 1.42–2.38), presence of liver metastasis (Pooled HR: 4.23, 95% CI 2.18–8.20), higher neutrophil–lymphocyte ratio (NLR) (Pooled HR: 1.29, 95% CI 1.07–1.55) and, higher c-reactive protein (CRP) (Pooled HR: 2.49, 95% CI 1.52–4.07). Metastatic UC patients with poor PS, liver metastasis, higher pretreatment NLR and/or CRP have a worse survival despite pembrolizumab treatment. These findings might help to guide the prognostic tools for clinical decision-making; however, they should be interpreted carefully, owing to limitations regarding the retrospective nature of primary data.

Defining the correlation between immune-checkpoint inhibitors-related adverse events and clinical outcomes: a narrative review

Immune checkpoint inhibitors (ICIs) have increased modern anticancer armamentarium portfolios, with 15%-60% of cancer patients deriving clinical benefit while others progress, including some occurrences of accelerated progressions. ICIs have also introduced a new pattern of immune-related adverse events (irAEs). Recently, a mechanistic link was proposed in which patients who develop ICIs-related irAEs derive a survival benefit compared to those who do not, suggesting an overlap between toxicities and the treatment efficacy. Identifying predictive biomarkers to optimally identify patients who will benefit from ICIs is a contemporary research area in Oncology. However, the data remains sparse, with only several smaller studies showing a plausible direct proportionality of a therapeutic effect across tumours. In contrast, the overall survival and progression-free survival rate depend on the tumour type, degree of toxicities, duration of exposure, affected system/organs and inherent patient characteristics. Furthermore, the occurrence of irAEs appears to be more associated with a clinical benefit from programmed death 1 and programmed death-ligand 1 inhibitors than anti-cytotoxic T-lymphocyte-associated antigen 4. Several questions remain unanswered, including the association between survival benefit and specific type of organ system toxicities, toxicity grade, if the benefit is entirely due to immortal-time biases (ITBs), presence of patients confounding comorbidities like autoimmune diseases, and finally, immune heterogeneities. Considering ITB represents a key element in interpreting these studies since patients with precipitated death or with an earlier disease progresses rarely develop irAEs; in fact, such patients have not stayed in the study long enough to experience such irAEs. Conversely, patients that stayed in the study for a longer period have a higher risk of developing irAEs. Landmark analysis is key in these studies if a real association is to be found. Overall response and disease control rates are mainly higher in those who develop irAEs due to immune activation. So, this review aims to summarise the evidence from key studies that addressed this important clinical question.

Advanced Non-Small Cell Lung Cancer Patients With Low Tumor Mutation Burden Might Derive Benefit From Immunotherapy

The aim of this study is to investigate the association between tumor mutation burden (TMB) and survival in non-small cell lung cancer (NSCLC) patients with anti-programmed cell death protein 1 and anti-programmed death-ligand 1 blockade. Two retrospective cohorts and The Cancer Genome Atlas NSCLC data set were included in this study. The restricted cubic spline analysis was used to explore the association between TMB and survival. The cutoff values for TMB were determined by X-tile software. Primary outcomes were overall survival (OS). The associations between TMB and intratumor heterogeneity, number of segments, fraction of genome alterations, aneuploidy score, and T-cell populations were also investigated. In the restricted cubic spline plots, TMB showed an inverted U-shaped curve with OS. The median OS in the low TMB group was significantly longer than those in the medium TMB group. In The Cancer Genome Atlas NSCLC data set, low TMB was also associated with longer OS in comparison with medium TMB. Furthermore, NSCLC patients with low TMB had significantly lower intratumor heterogeneity, number of segments, fraction of genome alterations, aneuploidy score, T-helper type 2 (Th2) cells, and CD8 T cells, but higher levels of Th1 and Th17 cells. Low TMB might be a prognostic factor for NSCLC patients receiving anti-programmed cell death protein 1/programmed death-ligand 1 immunotherapy.

Clinical Trials of Immune Checkpoint Inhibitors in Hepatocellular Carcinoma

Introduction: Several immune checkpoint inhibitors (CPIs) are under clinical development in hepatocellular carcinoma (HCC) and the field is advancing rapidly. In this comprehensive review, we discuss published results and report on ongoing clinical trials. Methods: A literature search was carried out using PubMed and EMBASE; data reported at international meetings and clinicaltrials.gov were included as well. The search was updated 5 March 2021. We evaluated studies with monotherapy CPI's, combinations of CPI's and combinations of CPI's with other treatment modalities separately. Only studies with at least 10 included patients were considered. Results: We identified 2649 records published in the English language literature. After review, 29 studies remained, including 12 studies with preliminary data only. The obtained overall response rate of PD-1/PDL-1 monotherapy in phase II studies in the second-line setting was 15-20% with disease control in approximately 60% of patients. The responses were of long duration in a subset of patients. Furthermore, the safety profiles were manageable. However, a phase III study comparing nivolumab with sorafenib in the first-line setting and a phase III study evaluating pembrolizumab versus best supportive care in the second-line setting did not meet their prespecified endpoints. More recently, a phase I/II study of nivolumab and ipilimumab has resulted in a response rate of approximately 30% with a median OS of 22 months in the second-line setting. Multiple trials have been initiated to evaluate CPIs in combination with molecularly targeted drugs, especially anti-angiogenic drugs or local therapy. A phase III study investigating atezolizumab plus bevacizumab versus sorafenib in the first-line setting showed significantly increased survival in the combination arm. Conclusions: The combination of atezolizumab and bevacizumab represents a new standard of care in the first-line setting for fit patients with preserved liver function. CPIs can produce durable tumor remission and induce long-standing anti-tumor immunity in a subgroup of patients with advanced HCC. Although phase III trials of CPI monotherapy have been negative, the combination of PD-1/PD-L1 inhibitors with other anti-angiogenic drugs, CTLA-4 inhibitors or other modalities may result in new treatment options for patients with HCC. Research on predictive biomarkers is crucial for further development of CPIs in HCC.

Combination immunotherapy with ipilimumab and nivolumab in patients with advanced adrenocortical carcinoma: a subgroup analysis of CA209-538

Background: Adrenocortical carcinoma is a rare malignancy, with poor prognosis and limited treatment options for patients with advanced disease. Chemotherapy is the current standard first-line treatment, providing only a modest survival benefit. There is only limited treatment experience with immunotherapy using single-agent anti-PD-1/PD-L1 therapy. To date no clinical trials have been reported using combination immunotherapy with anti-CTLA-4 and anti-PD-1 blockade in this patient population. Methods: CA209-538 is a prospective multicentre clinical trial in patients with advanced rare cancers. Participants received the anti-PD-1 antibody nivolumab (3 mg/kg IV) and the anti-CTLA-4 antibody ipilimumab (1 mg/kg IV) every three weeks for four doses, followed by nivolumab (3 mg/kg IV) every two weeks and continued for up to 96 weeks, until disease progression or unacceptable toxicity. Response was assessed every 12 weeks by RECIST version 1.1. Primary endpoint was clinical benefit rate (complete response, partial response, stable disease at 12 weeks). Results: Six patients with adrenocortical carcinoma were enrolled and received treatment. Two patients (33%) have an ongoing partial response (10 and 25 months +) and two patients (33%) stable disease leading to a disease control rate of 66%. Both responders had tumors with a microsatellite instable phenotype. One patient rapidly progressed shortly after enrollment into the trial and did not undergo restaging. Immunotherapy-related toxicity was reported in all patients, with four patients (67%) experiencing grade 3/4 hepatitis leading to discontinuation of treatment. Conclusions: This is the first treatment experience using ipilimumab and nivolumab combination immunotherapy in patients with advanced adrenocortical carcinoma. Durable responses have been observed in a subset of patients suggesting that this treatment regimen should be further investigated in this patient population.

Radiomics analysis for predicting pembrolizumab response in patients with advanced rare cancers

BACKGROUND

We present a radiomics-based model for predicting response to pembrolizumab in patients with advanced rare cancers.

METHODS

The study included 57 patients with advanced rare cancers who were enrolled in our phase II clinical trial of pembrolizumab. Tumor response was evaluated using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and immune-related RECIST (irRECIST). Patients were categorized as 20 "controlled disease" (stable disease, partial response, or complete response) or 37 progressive disease). We used 3D-slicer to segment target lesions on standard-of-care, pretreatment contrast enhanced CT scans. We extracted 610 features (10 histogram-based features and 600 second-order texture features) from each volume of interest. Least absolute shrinkage and selection operator logistic regression was used to detect the most discriminatory features. Selected features were used to create a classification model, using XGBoost, for the prediction of tumor response to pembrolizumab. Leave-one-out cross-validation was performed to assess model performance.

FINDINGS

The 10 most relevant radiomics features were selected; XGBoost-based classification successfully differentiated between controlled disease (complete response, partial response, stable disease) and progressive disease with high accuracy, sensitivity, and specificity in patients assessed by RECIST (94.7%, 97.3%, and 90%, respectively; p<0.001) and in patients assessed by irRECIST (94.7%, 93.9%, and 95.8%, respectively; p<0.001). Additionally, the common features of the RECIST and irRECIST groups also highly predicted pembrolizumab response with accuracy, sensitivity, specificity, and p value of 94.7%, 97%, 90%, p<0.001% and 96%, 96%, 95%, p<0.001, respectively.

CONCLUSION

Our radiomics-based signature identified imaging differences that predicted pembrolizumab response in patients with advanced rare cancer.

INTERPRETATION

Our radiomics-based signature identified imaging differences that predicted pembrolizumab response in patients with advanced rare cancer.

PD-1 Immune Checkpoint Inhibitor Therapy Malignant Tumor Based on Monotherapy and Combined Treatment Research

Recently, immunotherapy has become the fourth pillar of cancer treatment in addition to surgery therapy, chemotherapy, and radiation therapy. The inhibitors of programed cell death protein 1 (PD-1) and its ligand PD-L1 are the new stars in immunotherapy, as they can overcome tumor immunosuppression. However, the efficacy of PD-1 inhibitors still needs to be further developed for clinical treatment. Therefore, research into treatment with anti-PD-1 drugs has emerged as a new development field. This review provides novel insights into the role and mechanism of PD-1 combination anti-tumor therapy, thereby promoting its clinical application in anti-tumor immunotherapy.

Association of TRF2 expression and myeloid-derived suppressor cells infiltration with clinical outcome of patients with cutaneous melanoma

The outcome of patients with cutaneous melanoma has been strongly modified by recent advances obtained with Immune Checkpoint Inhibitors (ICIs). However, despite this breakthrough, durable response to ICIs is limited to a subset of patients. We investigated whether the expression of TRF2, which preserves telomere integrity, and have an effect on tumor immunosurveillance notably by directly recruiting and activating myeloid-derived suppressor cells (MDSCs), could be a prognostic biomarker in patients with relapsed or metastatic melanoma based on different treatment regimens. We evaluated retrospectively the association of TRF2 expressed in melanoma cells in combination with intratumoral CD33+ CD15+ CD14- MDSCs, as detected by immunohistochemistry and quantified by digital analysis, to clinicopathological features and overall survival (OS) among 48 patients treated with ICIs and 77 patients treated with other treatment options. The densities/mm² of TRF2+ cells (P=.003) and CD33+ cells (P=.004) were individually significantly related to poor OS. In addition, only the combined expression of CD33+/CD15+/CD14- cells/mm² was significantly correlated to poor OS (P=.017) in the whole study population as well as in patients treated by ICIs (P=.023). There was no significant difference in OS when analyzing the other markers individually or in combination according to the treatment regimen. The pre-treatment assessment of TRF2 expression and CD33+ cells/mm² along with the density of CD33+/CD15+/CD14- cells/mm² could assess OS and better predict clinical response of patients with melanoma treated by ICIs.

Dosage of anti-PD-1 monoclonal antibodies: a cardinal open question

Discovery and clinical development of monoclonal antibodies with the ability to interfere in the regulation of the immune response have significantly changed the landscape of oncology in recent years. Among the active agents licensed by the regulatory agencies, nivolumab and pembrolizumab are paradigmatic as the most relevant ones according to the magnitude of available data derived from the extensive preclinical and clinical experience. Although in both cases the respective data sheets indicate well-defined dosage regimens, a review of the literature permits to verify the existence of many issues still unresolved about dosing the two agents, so it must be considered an open question of potentially important consequences, in which to work to improve the effectiveness and efficiency of use.

Pembrolizumab in vaginal and vulvar squamous cell carcinoma: a case series from a phase II basket trial

Vaginal and vulvar squamous cell carcinoma (SCC) are rare tumors that can be challenging to treat in the recurrent or metastatic setting. We present a case series of patients with vaginal or vulvar SCC who were treated with single-agent pembrolizumab as part of a phase II basket clinical trial to evaluate efficacy and safety. Two cases of recurrent and metastatic vaginal SCC, with multiple prior lines of systemic chemotherapy and radiation, received pembrolizumab. One patient had significant reduction (81%) in target tumor lesions prior to treatment discontinuation at cycle 10 following confirmed progression of disease with new metastatic lesions (stable disease by irRECIST criteria). In contrast, the other patient with vaginal SCC discontinued treatment after cycle 3 due to disease progression. Both patients had PD-L1 positive vaginal tumors and tolerated treatment well. One case of recurrent vulvar SCC with multiple surgical resections and prior progression on systemic carboplatin had a 30% reduction in her target tumor lesions following pembrolizumab treatment with a PD-L1 positive tumor. Treatment was discontinued for grade 3 mucositis after cycle 5. Pembrolizumab may provide some clinical benefit to some patients with vaginal or vulvar SCC and is overall safe to utilize in this population. Future studies are needed to evaluate the efficacy of pembrolizumab in these rare tumor types and to identify predictive biomarkers of response.

The Multiple Potential Biomarkers for Predicting Immunotherapy Response-Finding the Needle in the Haystack

Immune checkpoint inhibitors (ICIs) are being increasingly utilised in a variety of advanced malignancies. Despite promising outcomes in certain patients, the majority will not derive benefit and are at risk of potentially serious immune-related adverse events (irAEs). The development of predictive biomarkers is therefore critical to personalise treatments and improve outcomes. A number of biomarkers have shown promising results, including from tumour (programmed cell death ligand 1 (PD-L1), tumour mutational burden (TMB), stimulator of interferon genes (STING) and apoptosis-associated speck-like protein containing a CARD (ASC)), from blood (peripheral blood mononuclear cells (PBMCs), circulating tumour DNA (ctDNA), exosomes, cytokines and metal chelators) and finally the microbiome.

The clinical efficacy and safety of single-agent pembrolizumab in patients with recurrent granulosa cell tumors of the ovary: a case series from a phase II basket trial

Background Treatment of recurrent, unresectable granulosa cell tumor (GCT) of the ovary can be challenging. Given the rarity of the tumor, alternative therapies have been difficult to evaluate in large prospective clinical trials. Currently, to our knowledge, there are no reports of the use of immune checkpoint inhibitors in GCT patients. Here, we present a case series of GCT patients treated with pembrolizumab who were enrolled in a phase II basket trial in advanced, rare solid tumors (ClinicalTrials.gov: NCT02721732). Cases We identified 5 patients with recurrent GCT (4 adult and 1 juvenile type); they had an extensive history of systemic therapy at study enrollment (range, 3-10), with most regimens resulting in less than 12 months of disease control. Pembrolizumab was administered in these patients, as per trial protocol. Although there were no objective responses according to the irRECIST guidelines, 2 patients with adult-type GCT experienced disease control for ≥ 12 months (565 and 453 days). In one, pembrolizumab represented the longest duration of disease control compared to prior lines of systemic therapy (565 days vs. 13 months). In the other, pembrolizumab was the second longest systemic therapy associated with disease control (453 days vs. 22 months) compared to prior lines of therapy. In this patient, pembrolizumab was discontinued following withdrawal of consent. PD-L1 expression was not observed in any baseline tumor samples. Pembrolizumab was well tolerated, with no grade 3 or 4 treatment-related adverse events. Conclusions Although our results do not support the routine use of pembrolizumab monotherapy in unselected GCT patients, some patients with adult-type GCT may derive a clinical benefit, with a low risk of toxicity. Future studies should investigate the role of immunotherapy and predictors of clinical benefit in this patient population.

Landscape of Immunotherapy in Genitourinary Malignancies

The past decade has witnessed a revolution in the development of immune checkpoint inhibitors for the treatment of multiple tumor types, including genitourinary cancers. Immune checkpoint inhibitors have notably improved the treatment outcomes of patients with metastatic renal cell carcinoma and metastatic urothelial carcinoma. In prostate cancer, the role of immunotherapy with checkpoint inhibitors is not yet established except for microsatellite instability high (MSI-H) tumors. Other immunotherapeutic approaches that have been explored in these malignancies include cytokines, vaccines, and cellular therapy. Ongoing studies are exploring the use of immunotherapy combinations as well as combination with chemotherapy and targeted therapy in these types of tumors. The use of immunotherapy beyond the metastatic setting is an active area of research. Moreover, there is great interest in biomarker development to predict response to immunotherapy and risk of toxicity. This book chapter is a comprehensive review of immunotherapeutic approaches, both approved and investigational, for the treatment of renal cell carcinoma, urothelial carcinoma, and prostate cancer.

Pembrolizumab as Consolidation Strategy in Patients with Multiple Myeloma: Results of the GEM-Pembresid Clinical Trial

Simple Summary

Multiple myeloma patients with persistent disease after treatment show increased expression of PDL1 in tumor plasma cells and of PD1 in T lymphocytes. This suggests a role of the PD1/PDL1 axis in treatment failure that could potentially be reverted with pembrolizumab, an anti-PD1 monoclonal antibody. The GEM-Pembresid trial enrolled 20 patients with multiple myeloma achieving a suboptimal response to the previous treatment that received intravenous pembrolizumab every 3 weeks with the objective of eradicating the residual disease. Pembrolizumab was acceptably well tolerated in the 17 patients evaluable for safety, but no improvement in the baseline responses was documented. Although no determinants of response could be identified, we detected a lower expression of PD1/PDL1 in a subgroup of patients progressing in the first 4 months after enrollment; furthermore, a reduction in the percentage of NK cells induced by pembrolizumab was observed.

Abstract

PD1 expression in CD4⁺ and CD8⁺ T cells is increased after treatment in multiple myeloma patients with persistent disease. The GEM-Pembresid trial analyzed the efficacy and safety of pembrolizumab as consolidation in patients achieving at least very good partial response but with persistent measurable disease after first- or second-line treatment. Moreover, the characteristics of the immune system were investigated to identify potential biomarkers of response to pembrolizumab. One out of the 17 evaluable patients showed a decrease in the amount of M-protein, although a potential late effect of high-dose melphalan could not be ruled out. Fourteen adverse events were considered related to pembrolizumab, two of which (G3 diarrhea and G2 pneumonitis) prompted treatment discontinuation and all resolving without sequelae. Interestingly, pembrolizumab induced a decrease in the percentage of NK cells at cycle 3, due to the reduction of the circulating and adaptive subsets (0.615 vs. 0.43, p = 0.007; 1.12 vs. 0.86, p = 0.02). In the early progressors, a significantly lower expression of PD1 in CD8⁺ effector memory T cells (MFI 1327 vs. 926, p = 0.03) was observed. In conclusion, pembrolizumab used as consolidation monotherapy shows an acceptable toxicity profile but did not improve responses in this MM patient population. The trial was registered at clinicaltrials.gov with identifier NCT02636010 and with EUDRACT number 2015-003359-23.

Biomarkers in Cutaneous Melanoma: Implications for Patient Education and Support

BACKGROUND

Elucidation of key biomarkers, as indicators and drivers of the pathologic processes in cutaneous melanoma (CM), has led to the development of effective targeted therapies.

OBJECTIVES

This article provides an overview of key concepts in advanced CM, particularly the essential role of biomarkers and biomarker testing to guide treatment.

METHODS

A comprehensive literature search was conducted in CINAHL® and PubMed® using the following search terms.

FINDINGS

Targeted BRAF/MEK inhibitors, as well as immune checkpoint inhibitors, have vastly improved long-term outcomes in advanced CM. Deepening understanding of the biologic and genomic features of CM and their interactions with the host immune system is critical for predicting treatment and survival outcomes and developing new therapies.

Randomized trials with checkpoint inhibitors in acute myeloid leukaemia and myelodysplastic syndromes: What have we learned so far and where are we heading?

The treatment of acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS) has seen dramatic advances with the approval of multiple novel agents in recent years. However, unlike solid malignancies, immune checkpoint inhibitors have yet to garner regulatory approval in AML and MDS with recent randomized clinical trials yielding only underwhelming results. Novel targets have been explored in early phase clinical trials with impressive results leading to ongoing subsequent controlled trials. However, major challenges in the field remain such as the validation of predictive genetic, molecular, and immunophenotypic biomarkers, optimization of clinical trial design, and the identification of novel synergistic combination therapies. Herein, we review recent clinical trial data focusing on randomized clinical trials and highlight limitations of the currently available evidence in an effort to suggest options for advancing the field.

Clinical application of immune checkpoints in targeted immunotherapy of prostate cancer

Immunotherapy is considered as an effective method for cancer treatment owing to the induction of specific and long-lasting anti-cancer effects. Immunotherapeutic strategies have shown significant success in human malignancies, particularly in prostate cancer (PCa), a major global health issue regarding its high metastatic rates. In fact, the first cancer vaccine approved by FDA was Provenge, which has been successfully used for treatment of PCa. Despite the remarkable success of cancer immunotherapy in PCa, many of the developed immunotherapy methods show poor therapeutic outcomes. Immunosuppression in tumor microenvironment (TME) induced by non-functional T cells (CD4+ and CD8+), tolerogenic dendritic cells (DCs), and regulatory T cells, has been reported to be the main obstacle to the effectiveness of anti-tumor immune responses induced by an immunotherapy method. The present review particularly focuses on the latest findings of the immune checkpoints (ICPs), including CTLA-4, PD-1, PD-L1, LAG-3, OX40, B7-H3, 4-1BB, VISTA, TIM-3, and ICOS; these checkpoints are able to have immune modulatory effects on the TME of PCa. This paper further discusses different approaches in ICPs targeting therapy and summarizes the latest advances in the clinical application of ICP-targeted therapy as monotherapy or in combination with other cancer therapy modalities in PCa.

Prognostic value of pre-treatment risk stratification and post-treatment neutrophil/lymphocyte ratio change for pembrolizumab in patients with advanced urothelial carcinoma

BACKGROUND

Pembrolizumab is effective in a limited number of patients with advanced urothelial carcinoma (UC). Therefore, we evaluated the prognostic value of clinical biomarkers following pembrolizumab treatment in patients with advanced UC.

METHODS

We retrospectively reviewed the medical records of 121 patients with platinum-refractory advanced UC who received pembrolizumab. Inflammation-based prognostic scores before and 6 weeks after the treatment were recorded. The categorical variables influencing overall survival (OS) and objective response rate (ORR) were analyzed.

RESULTS

Multivariate analyses showed that pretreatment Eastern Cooperative Oncology Group (ECOG) performance score (PS), presence of only lymph node metastasis (only LN mets), C-reactive protein (CRP), and neutrophil/lymphocyte ratio (NLR) were independent prognostic factors for OS (P = 0.0077; RR = 2.42, P = 0.0049; RR = 0.36, P = 0.0047; RR = 2.53, and P = 0.0079; RR = 2.33, respectively). The pretreatment risk stratification using ECOG PS, only LN mets, CRP, and NLR was used for estimating the OS (P < 0.0001) and ORR (P < 0.0001). Furthermore, changes in NLR in response to pembrolizumab were significantly associated with the OS (P = 0.0002) and ORR (P = 0.0023). This change was also significantly correlated with OS even in the high-risk group stratified by this pretreatment risk stratification (P = 0.0069).

CONCLUSIONS

This pretreatment risk stratification may be used for estimating the OS and ORR of patients with advanced UC treated with pembrolizumab. If changes in NLR in response to pembrolizumab treatment improve, pembrolizumab should be continued.

Phase II study of pembrolizumab efficacy and safety in women with recurrent small cell neuroendocrine carcinoma of the lower genital tract

OBJECTIVE

To investigate the efficacy and safety of pembrolizumab in women with recurrent small cell neuroendocrine tumors of the lower genital tract.

METHODS

We conducted an open-label, investigator-initiated phase II basket trial of pembrolizumab 200 mg intravenously every 3 weeks in patients with rare tumors (ClinicalTrials.gov: NCT02721732). The trial had prespecified cohorts, including small cell malignancies of extrapulmonary origin. Eligibility criteria included disease progression during standard treatment in the 6 months before study enrollment. Patients were enrolled from February 2017 to February 2019. The primary endpoint was the proportion of patients alive without progression at 27 weeks. Response to pembrolizumab was evaluated every 9 weeks (3 cycles) with radiographic imaging.

RESULTS

Seven women with gynecologic extrapulmonary small cell carcinoma were enrolled, 6 with cervical and 1 with vulvar carcinoma. No patient was progression free at 27 weeks. At first radiologic assessment, 1 patient had stable disease, while 6 had progression. The single patient with stable disease at 6 weeks had disease progression at 14 weeks. The median progression-free interval was 2.1 months (range 0.8-3.3 months). Severe treatment-related adverse events (≥grade 3) were seen in 2 of 7 patients (29%); 1 patient had grade 3 asymptomatic elevation of serum alkaline phosphatase, and 1 had grade 3 asymptomatic elevation of serum alanine aminotransferase.

CONCLUSIONS

Pembrolizumab alone showed minimal activity in women with recurrent small cell neuroendocrine tumors of the lower genital tract. Treatment was well tolerated in the majority of study participants, and the rate of severe adverse events was low.

Multiple Immune-Related Adverse Events and Anti-Tumor Efficacy: Real-World Data on Various Solid Tumors

Purpose

Immune checkpoint inhibitors (ICIs) have been approved for various types of cancer; however, they cause a broad spectrum of immune-related adverse events (irAEs). The association between the development of irAEs and the clinical benefit remains uncertain. We aimed to evaluate the association of irAEs and the treatment efficacy in real-world practice.

Patients and Methods

We conducted a retrospective study on patients with recurrent or metastatic non-small-cell lung cancer, malignant melanoma, renal cell carcinoma, or gastric cancer who received anti-PD-1/PD-L1 antibodies (nivolumab, pembrolizumab, or atezolizumab) at the Keio University Hospital between September 2014 and January 2019. We recorded treatment-related AEs from medical records and graded them using the Common Terminology Criteria for Adverse Events version 4. We performed an overall survival (OS) analysis using a Cox proportional hazards model and the shared frailty model.

Results

Of 212 patients eligible for this study, 108 experienced irAEs and 42 developed multiple irAEs. The median OS was significantly longer in the irAEs than in the no-irAE group (28.1 months vs 12.7 months; hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.33–0.73; P = 0.0004). Moreover, the OS of patients with multiple irAEs was significantly longer than that of patients with a single irAE (42.3 months vs 18.8 months; HR, 0.473; 95% CI, 0.346–0.647; P < 0.0001).

Conclusion

Our single-center retrospective study revealed a significant tendency associating the development of multiple irAEs with favorable prognoses.

Immune checkpoint inhibition in myeloid malignancies: Moving beyond the PD-1/PD-L1 and CTLA-4 pathways

Immune checkpoint inhibitors (ICI) have yielded mixed but largely underwhelming results in clinical trials in patients with acute myeloid leukemia and myelodysplastic syndromes to date. However, increasing understanding of the immunologic landscape, potential biomarkers for benefits, and mechanisms of resistance, as well as the use of rational combinations, and identification of novel targets leaves plenty of room for optimism. Herein, we review recent advances in the preclinical and clinical development of ICI therapy in patients with myeloid malignancies and explore some of the important challenges facing the field such as the absence of validated biomarkers, the development of synergistic and safe combination therapies, and efforts to determine the best setting of ICI along the disease course. We finally foresee the future of the field and propose solutions to some of the major beforementioned obstacles.

Prognostic value of risk stratification using blood parameters for nivolumab in Japanese patients with metastatic renal-cell carcinoma

BACKGROUND

Nivolumab is a standard treatment for previously treated advanced renal-cell carcinoma. However, nivolumab is effective in only a limited number of patients; therefore, we evaluated the prognostic value of several biomarkers, including inflammation-based prognostic scores and changes in these scores following nivolumab treatment in Japanese patients with metastatic renal-cell carcinoma.

METHODS

We retrospectively reviewed the medical records of 65 patients with previously treated metastatic renal-cell carcinoma and who received nivolumab. Inflammation-based prognostic scores, including neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, lymphocyte/monocyte ratio, and Glasgow prognostic score before and 6 weeks after the treatment were recorded. Categorical variables influencing disease-specific survival were compared using Cox proportional-hazards regression models.

RESULTS

Univariate analysis showed that Memorial Sloan-Kettering Cancer Center risk score (P = 0.0052), lactate dehydrogenase (P = 0.0266), lymphocyte/monocyte ratio (P = 0.0113), and platelet/lymphocyte ratio (P = 0.0017) had a significant effect on disease-specific survival. Multivariate analyses showed that platelet/lymphocyte ratio and lactate dehydrogenase were found to be independent prognostic factors for disease-specific survival (P = 0.0008, risk ratio (RR) = 7.95, 95% confidence interval, 2.16-51.64 and P = 0.0123, RR = 3.92, 95% confidence interval, 1.37-10.80, respectively). The combination of platelet/lymphocyte ratio and lactate dehydrogenase was the most significant prognostic biomarker in metastatic renal-cell carcinoma (P < 0.0001). Changes in lymphocyte/monocyte ratio and platelet/lymphocyte ratio in response to nivolumab were significant prognostic factors for disease-specific survival (P < 0.0001 and P = 0.0477, respectively).

CONCLUSIONS

The combination of platelet/lymphocyte ratio and lactate dehydrogenase may be a potential biomarker for estimating disease-specific survival in Japanese patients with metastatic renal-cell carcinoma treated by nivolumab.

Immunophenotyping of the PD-L1-positive cells in angioimmunoblastic T cell lymphoma and Hodgkin disease

Objective

Programmed death-1 (PD-1) and its ligand PD-L1 are now used as predictive biomarkers to guide clinical decisions. Precise characterization of PD-L1-positive cells may contribute to our knowledge of which patients derive benefit from the PD-L1 blockade therapy.

Results

To address this issue, we performed immunophenotyping of PD-L1-positive cells in Hodgkin lymphoma and in angioimmunoblastic T cell lymphoma (AITL) employing multiple immunofluorescent immunolabeling. We found that PD-L1-positive cells and PD-1-positive cells both in Hodgkin lymphoma and in AITL belong to two completely different cell lineages. In both lymphomas, PD-1 was found exclusively in T-lymphocytes, whereas PD-L1 was revealed in the tumor microenvironment cells including macrophages. PD-L1 was also detected in CD30-positive cells in Hodgkin lymphoma but not in AITL. The marker of B-cell lineage, CD20, was not detectable in PD-L1-positive cells both in AITL and in Hodgkin. Our study highlights the importance of comprehensive assessment of PD-1/PD-L1 regulatory pathways for employing PD-L1 as a predictive biomarker in clinical practice. PD-L1-antibody therapy is proven in Hodgkin lymphoma. Comparative immunophenotyping of the PD-1/PD-L1 axis provides a support for attempts to prove this principle also for AITL.

Specific T-cell immune responses against colony-forming cells including leukemic progenitor cells of AML patients were increased by immune checkpoint inhibition

The efficacy of immunotherapies in cancer treatment becomes more and more apparent not only in different solid tumors but also in hematological malignancies. However, in acute myeloid leukemia (AML), mechanisms to increase the efficacy of immunotherapeutic approaches have to be further elucidated. Targeting leukemic progenitor and stem cells (LPC/LSC) by specific CTL, for instance, in an adjuvant setting or in minimal residual disease, might be an option to prevent relapse of AML or to treat MRD. Therefore, we investigated the influence of immune checkpoint inhibitors on LAA-specific immune responses by CTL against leukemic myeloid blasts and colony-forming cells including leukemic progenitor cells (CFC/LPC). In functional immunoassays like CFU/CFI (colony-forming units/immunoassays) and ELISpot analysis, we detected specific LAA-directed immune responses against CFC/LPC that are postulated to be the source population of relapse of the disease. The addition of nivolumab (anti-PD-1) significantly increases LAA-directed immune responses against CFC/LPC, no effect is seen when ipilimumab (anti-CTLA-4) is added. The combination of ipilimumab and nivolumab does not improve the effect compared to nivolumab alone. The anti-PD1-directed immune response correlates to PD-L1 expression on progenitor cells. Our data suggest that immunotherapeutic approaches have the potential to target malignant CFC/LPC and anti-PD-1 antibodies could be an immunotherapeutic approach in AML. Moreover, combination with LAA-directed vaccination strategies might also open interesting application possibilities.

Clinical Characteristics and Adverse Impact of Hepatotoxicity due to Immune Checkpoint Inhibitors

INTRODUCTION

We conducted this study to characterize the incidence, clinical features, treatment, and outcomes of immune checkpoint inhibitor (ICI) hepatotoxicity.

METHODS

Patients who received ICIs (with either single-agent or combination regimens) from January 1, 2010, to March 31, 2018, were identified. Hepatotoxicity was defined as alanine aminotransferase (ALT) >5 times the upper limit of normal (ULN), in the absence of an alternate cause, and categorized as grade 3 (ALT 5-20× ULN) or grade 4 (ALT >20× ULN), according to Common Terminology Criteria for Adverse Events 4.03.

RESULTS

Among 5,762 patients, 100 (2%) developed hepatotoxicity, occurring in a higher proportion of recipients of combination therapy (9.2%) compared with monotherapy (up to 1.7%, P < 0.001). ICIs were discontinued permanently in 69 and temporarily in 31 patients. Sixty-seven patients received steroids, 10 of whom (14%) had recurrent hepatotoxicity after the steroid taper. Thirty-one patients resumed ICIs after ALT improvement, 8 of whom (26%) developed recurrent hepatotoxicity. Characteristics of liver injury, response to steroids, and outcomes were similar between 38 individuals with and 62 without possible pre-existing liver disease. The severity and outcome of hepatotoxicity due to combination therapy were not significantly different from monotherapy. There were 36 deaths. Two had liver failure at the time of death, both with progression of liver metastases and grade 3 hepatotoxicity.

DISCUSSION

Clinically significant ICI-related hepatotoxicity was uncommon but led to permanent ICI discontinuation in the majority. ICIs were restarted in a sizable proportion of patients, most of whom did not experience recurrent hepatotoxicity.

Advances in Diagnostic Procedures and Their Applications in the Era of Cancer Immunotherapy

Diagnostic procedures play critical roles in cancer immunotherapy. In this chapter, we briefly discuss three major diagnostic procedures widely used in immunotherapy: immunohistochemistry, next-generation sequencing, and flow cytometry. We also describe the uses of other diagnostic procedures and preclinical animal models in cancer immunotherapy translational research.

Immunotherapy in Lung Cancer: From a Minor God to the Olympus

Over the last decade, we have witnessed a paradigm shift in cancer treatment, with the advent of novel therapeutic approaches that target or manipulate the immune system, also known as immunotherapy. Blocking immune checkpoints has emerged as an effective strategy with unprecedented results in several solid tumors, including lung cancer. Since 2012 when PD(L)-1 inhibitors showed first clinical signals of activity in lung cancer, immune checkpoint blockade (ICB) has emerged as a novel effective therapeutic strategy in different settings, determining a dramatic change in the therapeutic landscape of both non-small cell lung cancer (NSCLC) and, more recently, small cell lung cancer (SCLC). Although the benefit from this novel therapeutic approach is undeniable, several open questions still remain unanswered. Herein, we summarize the major breakthroughs in the immunotherapy journey in lung cancer and how it is changing our clinical practice.