Enhancing antitumor response by combining immune checkpoint inhibitors with chemotherapy in solid tumors

Inhibition of topoisomerase I shapes antitumor immunity through the induction of monocyte-derived dendritic cells

Understanding the rationale of combining immunotherapy and other anticancer treatment modalities is of great interest because of interpatient variability in single-agent immunotherapy. Here, we demonstrated that topoisomerase I inhibitors, a class of chemotherapeutic drugs, can alter the tumor immune landscape, corroborating their antitumor effects combined with immunotherapy. We observed that topotecan-conditioned TC-1 tumors were occupied by a vast number of monocytic cells that highly express CD11c, CD64, and costimulatory molecules responsible for the favorable changes in the tumor microenvironment. Ly6C⁺MHC-II⁺CD11c^hiCD64^hi cells, referred to as topotecan-induced monocyte-derived dendritic cells (moDCs), proliferate and activate antigen-specific CD8⁺ T cells to levels equivalent to those of conventional DCs. Phenotypic changes in Ly6C⁺ cells towards moDCs were similarly induced by exposure to topotecan in vitro, which was more profoundly facilitated in the presence of tumor cells. Notably, anti-M-CSFR reversed the acquisition of DC-like properties of topotecan-induced moDCs, leading to the abolition of the antitumor effect of topotecan combined with a cancer vaccine. In short, topoisomerase I inhibitors generate monocyte-derived antigen-presenting cells in tumors, which could be mediated by M-CSF-M-CSFR signaling.

Potentiated antitumor effects of APS001F/5-FC combined with anti-PD-1 antibody in a CT26 syngeneic mouse model

APS001F is a strain of Bifidobacterium longum genetically engineered to express cytosine deaminase that converts 5-fluorocytosine (5-FC) to 5-fluorouracil. In the present study, antitumor effects of APS001F plus 5-FC (APS001F/5-FC) in combination with anti-PD-1 monoclonal antibody were investigated using a CT26 syngeneic mouse model. Both of dosing of APS001F/5-FC before and after anti-PD-1 mAb in the combination dosing exhibited antitumor effects as well as prolonged survival over the nontreated control. The survival rate in the combination therapy significantly increased over the monotherapy with APS001F/5-FC and that with anti-PD-1 mAb. Regulatory T cells among CD4+ T cells in tumor decreased in the combination therapy, while the ratio of CD8+ T cells was maintained in all groups. Taken these results together, APS001F/5-FC not only demonstrates a direct antitumor activity, but also immunomodulatory effects once localized in the hypoxic region of the tumor, which allows anti-PD-1 mAb to exert potentiated antitumor effects.

First-Line Treatment Options for PD-L1-Negative Non-Small Cell Lung Cancer: A Bayesian Network Meta-Analysis

Background

First-line treatment strategies for programmed death-ligand 1 (PD-L1) negative non-small cell lung cancer (NSCLC) patients include chemotherapy and combination with anti-angiogenesis drugs and/or immune checkpoint inhibitor. We conducted a Bayesian network meta-analysis to evaluate the efficacy of these therapeutic options.

Methods

We included phase III randomized controlled trials comparing two or more treatments in the first-line setting for NSCLC, including data in PD-L1–negative patients. First-line strategies were compared and ranked based on the effectiveness in terms of overall survival (OS) and progression-free survival (PFS). A rank was assigned to each treatment after Markov Chain Monte Carlo analyses.

Results

Fourteen trials involving 14 regimens matched our eligibility criteria. For OS, none of the treatment were significantly more effective than chemotherapy. Nivolumab plus ipilimumab plus chemotherapy was probably the best option based on analysis of the treatment ranking (probability = 30.1%). For PFS, nivolumab plus chemotherapy plus bevacizumab, atezolizumab plus chemotherapy plus bevacizumab, and atezolizumab plus chemotherapy were statistically superior to chemotherapy in pairwise comparison. Nivolumab plus chemotherapy plus bevacizumab was likely to be the preferred option based on the analysis of the treatment ranking (probability = 72.9%).

Conclusions

Nivolumab plus chemotherapy, in combination with angiogenesis inhibition or anti-cytotoxic T-lymphocyte–associated antigen 4 (CTLA-4), had maximal benefits for NSCLC patient of PD-L1–negative expression. These findings may facilitate individualized treatment strategies. Safety at an individual patient level should be considered in decision making. Further validation is warranted.

Classification of Non-Small Cell Lung Cancer's Tumor Immune Micro-Environment and Strategies to Augment Its Response to Immune Checkpoint Blockade

Simple Summary

Immune checkpoint blockade (ICB) has become a major treatment for lung cancer. Better understanding of the tumor immune micro-environment (TIME) in non-small cell lung cancer (NSCLC) is urgently needed to better treat it with this type of therapy. In this review, we describe and explore how NSCLC’s TIME relates to response to ICB, as well as how to treat those with unresponsive types of TIME, which will significantly impact future research in lung cancer immunotherapy.

Abstract

Immune checkpoint blockade (ICB) with checkpoint inhibitors has led to significant and durable response in a subset of patients with advanced stage EGFR and ALK wild-type non-small cell lung cancer (NSCLC). This has been consistently shown to be correlated with the unique characteristics of each patient’s tumor immune micro-environment (TIME), including the composition and distribution of the tumor immune cell infiltrate; the expression of various checkpoints by tumor and immune cells, such as PD-L1; and the presence of various cytokines and chemokines. In this review, the classification of various types of TIME that are present in NSCLC and their correlation with response to ICB in NSCLC are discussed. This is conducted with a focus on the characteristics and identifiable biomarkers of different TIME subtypes that may also be used to predict NSCLC’s clinical response to ICB. Finally, treatment strategies to augment response to ICB in NSCLC with unresponsive types of TIME are explored.

PD-L1 targeting high-affinity NK (t-haNK) cells induce direct antitumor effects and target suppressive MDSC populations

Background

Although immune checkpoint inhibitors have revolutionized cancer treatment, clinical benefit with this class of agents has been limited to a subset of patients. Hence, more effective means to target tumor cells that express immune checkpoint molecules should be developed. For the first time, we report a novel natural killer (NK) cell line, programmed death-ligand 1 (PD-L1) targeting high-affinity natural killer (t-haNK), which was derived from NK-92 and was engineered to express high-affinity CD16, endoplasmic reticulum-retained interleukin (IL)-2, and a PD-L1-specific chimeric antigen receptor (CAR). We show that PD-L1 t-haNK cells also retained the expression of native NK receptors and carried a high content of granzyme and perforin granules.

Methods

NanoString, flow cytometry, and immunofluorescence analyses were performed to characterize the phenotype of irradiated PD-L1 t-haNK cells. In vitro PD-L1 t-haNK cell activity against cancer cell lines and human peripheral blood mononuclear cells (PBMCs) was determined via flow-based and ¹¹¹In-release killing assays. The antitumor effect of PD-L1 t-haNK cells in vivo was investigated using MDA-MB-231, H460, and HTB1 xenograft models in NOD-scid IL2Rgamma^null (NSG) mice. Additionally, the antitumor effect of PD-L1 t-haNK cells, in combination with anti-PD-1 and N-803, an IL-15 superagonist, was evaluated using mouse oral cancer 1 syngeneic model in C57BL/6 mice.

Results

We show that PD-L1 t-haNK cells expressed PD-L1-targeting CAR and CD16, retained the expression of native NK receptors, and carried a high content of granzyme and perforin granules. In vitro, we demonstrate the ability of irradiated PD-L1 t-haNK cells to lyse 20 of the 20 human cancer cell lines tested, including triple negative breast cancer (TNBC) and lung, urogenital, and gastric cancer cells. The cytotoxicity of PD-L1 t-haNK cells was correlated to the PD-L1 expression of the tumor targets and can be improved by pretreating the targets with interferon (IFN)-γ. In vivo, irradiated PD-L1 t-haNK cells inhibited the growth of engrafted TNBC and lung and bladder tumors in NSG mice. The combination of PD-L1 t-haNK cells with N-803 and anti-PD-1 antibody resulted in superior tumor growth control of engrafted oral cavity squamous carcinoma tumors in C57BL/6 mice. In addition, when cocultured with human PBMCs, PD-L1 t-haNK cells preferentially lysed the myeloid-derived suppressor cell population but not other immune cell types.

Conclusion

These studies demonstrate the antitumor efficacy of PD-L1 t-haNK cells and provide a rationale for the potential use of these cells in clinical studies.

Identification of gastric cancer subtypes based on pathway clustering

Gastric cancer (GC) is highly heterogeneous in the stromal and immune microenvironment, genome instability (GI), and oncogenic signatures. However, a classification of GC by combining these features remains lacking. Using the consensus clustering algorithm, we clustered GCs based on the activities of 15 pathways associated with immune, DNA repair, oncogenic, and stromal signatures in three GC datasets. We identified three GC subtypes: immunity-deprived (ImD), stroma-enriched (StE), and immunity-enriched (ImE). ImD showed low immune infiltration, high DNA damage repair activity, high tumor aneuploidy level, high intratumor heterogeneity (ITH), and frequent TP53 mutations. StE displayed high stromal signatures, low DNA damage repair activity, genomic stability, low ITH, and poor prognosis. ImE had strong immune infiltration, high DNA damage repair activity, high tumor mutation burden, prevalence of microsatellite instability, frequent ARID1A mutations, elevated PD-L1 expression, and favorable prognosis. Based on the expression levels of four genes (TAP2, SERPINB5, LTBP1, and LAMC1) in immune, DNA repair, oncogenic, and stromal pathways, we developed a prognostic model (IDOScore). The IDOScore was an adverse prognostic factor and correlated inversely with immunotherapy response in cancer. Our identification of new GC subtypes provides novel insights into tumor biology and has potential clinical implications for the management of GCs.

Camrelizumab Combined with Chemotherapy Followed by Camrelizumab plus Apatinib as First-line Therapy for Advanced Gastric or Gastroesophageal Junction Adenocarcinoma

PURPOSE

Capecitabine plus oxaliplatin (CAPOX) is one of the standard first-line treatments for unresectable, advanced, or metastatic gastric or gastroesophageal junction (G/GEJ) adenocarcinoma. Camrelizumab shows promising antitumor activity in advanced or metastatic G/GEJ adenocarcinoma in a phase I study. We reported the outcomes of cohort 1 in a multicenter, open-label, phase II trial, which assessed camrelizumab in combination with CAPOX followed by camrelizumab plus apatinib as a first-line combination regimen for advanced or metastatic G/GEJ adenocarcinoma.

PATIENTS AND METHODS

Systemic treatment-naïve patients with EGFR2-negative advanced or metastatic G/GEJ adenocarcinoma received initial camrelizumab plus CAPOX for 4-6 cycles, and patients without progressive disease were administrated subsequent camrelizumab plus apatinib. Primary endpoint was objective response rate (ORR).

RESULTS

All 48 enrolled patients comprised the efficacy and safety analysis population. The ORR was 58.3% [95% confidence interval (CI), 43.2-72.4] with this combination regimen. Median duration of response was 5.7 months (95% CI, 4.4-8.3). Median overall survival was 14.9 months (95% CI, 13.0-18.6), and median progression-free survival was 6.8 months (95% CI, 5.6-9.5), respectively. The most common grade ≥3 treatment-related adverse events (>10%) were decreased platelet count (20.8%), decreased neutrophil count (18.8%), and hypertension (14.6%). Treatment-related death occurred in 1 patient (2.1%) due to abnormal hepatic function and interstitial lung disease.

CONCLUSIONS

Camrelizumab combined with CAPOX followed by camrelizumab plus apatinib demonstrated encouraging antitumor activity and manageable toxicity as first-line therapy for patients with advanced or metastatic G/GEJ adenocarcinoma.

Selection of optimal first-line immuno-related therapy based on specific pathological characteristics for patients with advanced driver-gene wild-type non-small cell lung cancer: a systematic review and network meta-analysis

Background

Although immune checkpoint inhibitors (ICIs) have improved survival for advanced wild-type non-small cell lung cancer (NSCLC), a lack of direct comparisons of various first-line treatments is clouding clinical decision-making. A network meta-analysis was conducted to compare current first-line treatments and identify the optimal regimen for patients with specific characteristics.

Methods

PubMed, Embase, the Cochrane Central Register of Controlled Trials, Clinical Trials databases were searched from inception to 31 July 2020. Phase II/III randomized controlled trials (RCTs) comparing first-line treatments including chemotherapy, anti-angiogenesis, ICIs, and their combinations for previously untreated stage IIIB/IV or recurrent driver-gene wild-type NSCLC patients were included.

Results

Twenty-six RCTs were identified and included, involving 16,977 patients and a total of 18 regimens. ICI-containing treatments led to significantly prolonged overall survival (OS) compared with ICI-free treatments (0.82, 0.72-0.93). ICI plus chemotherapy had significantly longer progression-free survival (PFS; 0.70, 0.58-0.86) and marginally longer OS (0.90, 0.79-1.05) compared with ICIs alone. Ranking highest in the Bayesian network meta-analysis, pembrolizumab plus chemotherapy, nivolumab plus ipilimumab and chemotherapy, had significantly superior OS than standard chemotherapy with or without bevacizumab treatments. Pembrolizumab-chemotherapy ranked first for OS, 1-year OS rate, and subgroups of non-squamous, PD-L1 ⩾1%, non-smoking, and liver metastasis; while nivolumab-ipilimumab-chemotherapy for squamous, PD-L1 <1%, brain metastasis NSCLC. Furthermore, the ICI-containing bevacizumab-free treatments, such as pembrolizumab plus chemotherapy, nivolumab and ipilimumab with or without chemotherapy, were not significantly different from atezolizumab plus chemotherapy and bevacizumab in OS.

Conclusions

A combination of ICIs with chemotherapy, rather than double ICIs, is the best first-line treatment for advanced wild-type NSCLC, with synergy that leads to better long-term survival. The panoramic view of the relative efficacy of any two regimens with different rankings provides strong evidence for selecting optimal first-line ICIs according to patients' clinical characteristics.

Development of Immunotherapy Combination Strategies in Cancer

Harnessing the immune system to treat cancer through inhibitors of CTLA4 and PD-L1 has revolutionized the landscape of cancer. Rational combination strategies aim to enhance the antitumor effects of immunotherapies, but require a deep understanding of the mechanistic underpinnings of the immune system and robust preclinical and clinical drug development strategies. We review the current approved immunotherapy combinations, before discussing promising combinatorial approaches in clinical trials and detailing innovative preclinical model systems being used to develop rational combinations. We also discuss the promise of high-order immunotherapy combinations, as well as novel biomarker and combinatorial trial strategies. SIGNIFICANCE: Although immune-checkpoint inhibitors are approved as dual checkpoint strategies, and in combination with cytotoxic chemotherapy and angiogenesis inhibitors for multiple cancers, patient benefit remains limited. Innovative approaches are required to guide the development of novel immunotherapy combinations, ranging from improvements in preclinical tumor model systems to biomarker-driven trial strategies.

Cancer-activated doxorubicin prodrug nanoparticles induce preferential immune response with minimal doxorubicin-related toxicity

The effective chemotherapeutic drug, doxorubicin (DOX), elicits immunogenic cell death (ICD) and additional anticancer immune responses during chemotherapy. However, it also induces severe side effects and systemic immunosuppression, hampering its wide clinical application. Herein, we constructed cancer-activated DOX prodrug by conjugating the cathepsin B-cleavable peptide (Phe-Arg-Arg-Gly, FRRG) to a doxorubicin (DOX), resulting in FRRG-DOX that self-assembled into cancer-activated DOX prodrug nanoparticles (CAP-NPs). The resulting CAP-NPs were further stabilized with the FDA-approved compound, Pluronic F68. CAP-NPs formed stable prodrug nanoparticles and they were specifically cleaved to cytotoxic DOX molecules only in cathepsin B-overexpressing cancer cells, inducing a cancer cell-specific cytotoxicity. In particular, the CAP-NPs induced ICD through cathepsin B-cleavage mechanism only in targeted cancer cells in vitro. In colon tumor-bearing mice, selectively accumulated CAP-NPs at tumors enhanced antitumor immunity without DOX-related severe toxicity, inflammatory response and systemic immunosuppression. Moreover, cytotoxicity against immune cells infiltrated into tumor microenvironment was significantly reduced compared to free DOX, leading to increased response to checkpoint inhibitor immunotherapy. The combinatorial treatment of CAP-NPs with anti-PD-L1 exhibited high rate of complete tumor regression (50%) compared to free DOX with anti-PD-L1. Concurrently, DOX-related side effects were greatly reduced during chemoimmunotherapy. Collectively, our results suggest that cancer-activated DOX prodrug nanoparticles provide a promising approach to increase clinical benefit by inducing an immune response preferentially only to targeted cancer cells, not to normal cells and immune cells, and potentiates checkpoint inhibitor immunotherapy.

Neoadjuvant immunotherapy for non-small cell lung cancer: State of the art

Lung cancer mortality has decreased over the past decade and can be partly attributed to advances in targeted therapy and immunotherapy. Immune checkpoint inhibitors (ICIs) have rapidly evolved from investigational drugs to standard of care for the treatment of metastatic non-small cell lung cancer (NSCLC). In particular, antibodies that block inhibitory immune checkpoints, such as programmed cell death protein 1 (PD-1) and programmed cell death 1 ligand 1 (PD-L1), have revolutionized the treatment of advanced NSCLC, when administered alone or in combination with chemotherapy. Immunotherapy is associated with higher response rates, improved overall survival (OS), and increased tolerability compared with conventional cytotoxic chemotherapy. These benefits may increase the utility of immunotherapy and its combinational use with chemotherapy in the neoadjuvant treatment of patients with NSCLC. Early findings from various ongoing clinical trials suggest that neoadjuvant ICIs alone or combined with chemotherapy may significantly reduce systemic recurrence and improve long-term OS or cure rates in resectable NSCLC. Here we further summarize the safety and efficacy of various neoadjuvant treatment regimens including immunotherapy from ongoing clinical trials and elaborate the role of neoadjuvant immunotherapy in patients with resectable NSCLC. In addition, we discuss several unresolved challenges, including the evaluations to assess neoadjuvant immunotherapy response, the role of adjuvant treatment after neoadjuvant immunotherapy, the efficacy of treatment for oncogenic-addicted tumors, and predictive biomarkers. We also provide our perspective on ways to overcome current obstacles and establish neoadjuvant immunotherapy as a standard of care.

Biological bases of cancer immunotherapy

Immunotherapy has changed the landscape of cancer treatment and has significantly improved the outcome of several cancer types including breast, lung, colorectal and prostate. Neoantigen recognition and immune checkpoint inhibitors are nowadays the milestones of different immunotherapeutic regimes; however, high cost, primary and acquired resistance and the high variability of responses make their extensive use difficult. The development of better predictive biomarkers that represent tumour diversity shows promise because there is a significant body of clinical data showing a spectrum of immunotherapeutic responses that might be related back to their specific characteristics. This article makes a conceptual and historical review to summarise the main advances in our understanding of the role of the immune system in cancer, while describing the methodological details that have been successfully implemented on cancer treatments and that may hold the key to improved therapeutic approaches.

Immune Checkpoints Inhibitors and Chemotherapy as First-Line Treatment for Metastatic Urothelial Carcinoma: A Network Meta-Analysis of Randomized Phase III Clinical Trials

Simple Summary

On the basis of the efficacy and tolerable safety profiles of immune checkpoints inhibitors (ICIs) in second-line metastatic urothelial carcinoma (mUC) patients, some emerging clinical trials focus on the first-line treatment. Thus, we conducted a network meta-analysis (NMA) to assess and compare the response and toxicity of ICIs in naïve-chemotherapy mUC setting. According to our results, combination therapy (either ICIs plus chemotherapy (CTX) or ICIs plus ICIs) had a higher priority in terms of overall survival. Concerning monotherapy, ICIs are not inferior to CTX in terms of OS. In view of the adverse effect, ICIs are very tolerable, and combination therapy did not lead to a higher incidence of grade 3–5 AEs when compared with CTX.

Abstract

Immune checkpoints inhibitors (ICIs) were considered as second-line treatments in metastatic urothelial carcinoma (mUC) based on better survival benefit and safety profile than chemotherapy (CTX). We aimed to assess different ICIs regimens in the efficacy and safety for front-line treatments in mUC patients. A comprehensive literature search was performed and Phase II-III randomized controlled trials (RCTs) on ICIs for patients with mUC were included. The outcome was evaluated by overall survival (OS), progression of free survival (PFS), objective response rate (ORR), and grade 3–5 adverse events. Network meta-analysis was used to estimate the effect size. Surface under cumulative ranking curves (SUCRAs) were applied to rank the included treatments for each outcome. Results: The survival benefit of a single ICI was non-inferiority to chemotherapy (CTX). Although no superior effects were indicated, combination therapy (either ICIs plus CTX or ICIs plus ICIs) presented better OS compared with CTX alone. In terms of PFS, combination therapy produced a noticeable benefit over CTX. Regarding the SUCRA ranking, atezolizumab plus CTX was associated with the best ranking for OS and pembrolizumab plus CTX was the best in PFS. In terms of safety, a single ICI had better safety profile than CTX and combination therapy had a similar risk of grade 3–5 adverse events with CTX. Conclusions: Our NMA results revealed that combination therapy has better ranking compared with monotherapy in OS and acceptable AEs. ICIs alone present non-inferior OS but a lower incidence of AEs compared with CTX.

Comparative Efficacy and Safety of Immunotherapy Alone and in Combination With Chemotherapy for Advanced Non-small Cell Lung Cancer

There is a lack of direct cross-comparison studies in clinical trials between immunotherapy alone and combination treatment, especially in Non-Small Cell Lung Cancer (NSCLC) patients with high PD-L1 expression. To determine if anti-PD-(L)1 antibody combined with chemotherapy is more efficient than immune checkpoint inhibitor (ICI) monotherapy for advanced NSCLC patients in the real-world data. We retrospectively collected 325 patients with advanced NSCLC treated with ICI alone with or without chemotherapy from 11th July 2016 to 26th May 2020 to investigate which treatment scenario is the most efficient, and how clinical factors impact response. Patients with advanced NSCLC were treated with ICI monotherapy (178/325, 54.8%) or in combination with chemotherapy (147/325, 45.2%). The objective response rate and disease control rate were higher in the combination group than the monotherapy group. Patients (including those with distant metastasis) treated with chemo-immunotherapy were associated with a significantly longer median PFS and OS compared with the monotherapy group, irrespective of the PD-L1 expression level and previous treatment lines. No significant increase in the risk of immune-related adverse events (irAEs) was found after combination with chemotherapy (50.6 vs. 57.8%). IrAEs predicted better PFS of immunotherapy in the monotherapy group, especially for patients with late irAEs (after ≥4 cycles). Collectively, we demonstrated that ICI monotherapy plus chemotherapy might have better anti-tumor activity and an acceptable side-effect profile regardless of PD-L1 level or previous treatment lines. Both regimens were well-tolerated and cost-effective, the more efficient is usually recommended.

Clinical Outcomes for Patients With Metastatic Breast Cancer Treated With Immunotherapy Agents in Phase I Clinical Trials

BACKGROUND

Immuno-oncology (IO) agents have demonstrated efficacy across many tumor types and have led to change in standard of care. In breast cancer, atezolizumab and pembrolizumab were recently FDA-approved in combination with chemotherapy specifically for patients with PD-L1-positive metastatic triple-negative breast cancer (TNBC). However, the single agent PD-1/PD-L1 inhibitors demonstrate only modest single agent efficacy in breast cancer. The purpose of this study was to investigate the efficacy of novel IO agents in patients with metastatic breast cancer (MBC), beyond TNBC, treated in phase I clinical trials at the University of Colorado.

METHODS

We performed a retrospective analysis using a database of patients with MBC who received treatment with IO agents in phase I/Ib clinical trials at the University of Colorado Hospital from January 1, 2012 to July 1, 2018. Patient demographics, treatments and clinical outcomes were obtained.

RESULTS

We identified 43 patients treated with an IO agent either as a single agent or in combination. The average age was 53 years; 55.8% had hormone receptor-positive/HER2-negative breast cancer, 39.5% TNBC and 4.7% HER2-positive. Patients received an average of 2 prior lines of chemotherapy (range 0-7) in the metastatic setting. Most patients (72.1%) received IO alone and 27.9% received IO plus chemotherapy. Median progression-free survival (PFS) was 2.3 months and median overall survival (OS) was 12.1 months. Patients remaining on study ≥ 6 months (20.9%) were more likely to be treated with chemotherapy plus IO compared to patients with a PFS < 6 months (77.8% v. 14.7%). No differences in number of metastatic sites, prior lines of chemotherapy, breast cancer subtype, absolute lymphocyte count, or LDH were identified between patients with a PFS ≥ 6 months vs. < 6 months.

CONCLUSIONS

Our phase I experience demonstrates benefit from IO therapy that was not limited to patients with TNBC and confirms improved efficacy from IO agents in combination with chemotherapy. A subset of patients with MBC treated in phase I clinical trials with an IO agent derived prolonged clinical benefit. Predictors of response to immunotherapy in breast cancer remain uncharacterized and further research is needed to identify these factors.

Integrating immunotherapy in the (neo)adjuvant setting of early breast cancer

PURPOSE OF REVIEW

Breast cancer is a relative latecomer in the success story of immuno-oncology. In this review, we focus on the preclinical and clinical lines of evidence to justify the evaluation of immune checkpoint inhibition (ICI) for the curative-intent treatment of breast cancer, the latest and ongoing trials of (neo)adjuvant immunotherapy, and practical considerations in clinical practice associated with this new treatment paradigm.

RECENT FINDINGS

Insights from the immunobiology of breast cancer have paved the way for the new frontier of immunotherapy in this malignancy, starting from advanced stages and moving onto curable cases. Tumor-infiltrating lymphocyte quantification and PD-L1 immunohistochemistry are forerunners of predictive biomarkers for sensitivity to ICI in breast cancers. Preliminary results from phase III trials of combinatorial immunochemotherapy to treat early high-risk or locally advanced triple-negative breast cancer are encouraging for pathological complete response. Additional efficacy and patient-reported outcomes of (neo)adjuvant immunochemotherapy trials are awaited.

SUMMARY

The prospect of integrating ICI in the treatment of early-stage breast cancer is promising. Questions regarding patient selection, the choice of ICI agent and combination partner in escalation strategies, sequencing and duration of treatments, cost-effectiveness and mechanisms of resistance remain to be answered by future research.

Immune-related adverse events associated with immune checkpoint inhibitors: An updated comprehensive disproportionality analysis of the FDA adverse event reporting system

BACKGROUNDS

Immune-related adverse events were reported in patients treated with immune checkpoint inhibitors (ICIs). However, with the increasing number of immune-related adverse events (irAEs), the differences of each immune checkpoint inhibitor regimen had not been fully assessed.

METHODS

Disproportionality analysis was used in data mining of the suspected adverse events after ICIs administration based on the Food and Drug Administration Adverse Event Reporting System (FAERS) from January 2004 to December 2019. The onset time and fatality proportion of ICI-associated irAEs were further evaluated.

RESULTS

A total of 32,441 reports of ICI-associated irAEs were gathered. This study showed that all ICI regimens generated lung toxicity and endocrine toxicity signals. Colitis, pneumonitis and interstitial lung disease were the most common ICI-associated irAEs. Five regimens including durvalumab monotherapy, ipilimumab monotherapy, ipilimumab plus nivolumab, ipilimumab plus pembrolizumab, durvalumab plus tremelimumab were associated with irAEs. Anti-PD-1 agents generated more signals of ocular toxicities than anti-PD-L1 agents, while anti-PD-L1 agents reported more signals of hematologic toxicities. Anti-CTLA-4 agents showed more signals of gastrointestinal toxicities compared with anti-PD-1 or anti-PD-L1 agents. The highest fatality proportion of lung toxicities with durvalumab monotherapy, hematological toxicities with avelumab monotherapy, renal and skin toxicities with cemiplimab monotherapy were found.

CONCLUSION

Our results demonstrated that each ICI regimen had different characteristics of irAEs. Pembrolizumab had the highest fatality proportion. Ipilimumab plus pembrolizumab had the shortest median time to onset irAEs. Further studies were expected to assess whether there were clinically relevant differences exist among ICIs.

Granzyme B PET Imaging of Combined Chemotherapy and Immune Checkpoint Inhibitor Therapy in Colon Cancer

Purpose

Chemotherapeutic adjuvants, such as oxaliplatin (OXA) and 5-fluorouracil (5-FU), that enhance the immune system, are being assessed as strategies to improve durable response rates when used in combination with immune checkpoint inhibitor (ICI) monotherapy in cancer patients. In this study, we explored granzyme B (GZB), released by tumor-associated immune cells, as a PET imaging-based stratification marker for successful combination therapy using a fluorine-18 (¹⁸F)-labelled GZB peptide ([¹⁸F]AlF-mNOTA-GZP).

Methods

Using the immunocompetent CT26 syngeneic mouse model of colon cancer, we assessed the potential for [¹⁸F]AlF-mNOTA-GZP to stratify OXA/5-FU and ICI combination therapy response via GZB PET. In vivo tumor uptake of [¹⁸F]AlF-mNOTA-GZP in different treatment arms was quantified by PET, and linked to differences in tumor-associated immune cell populations defined by using multicolour flow cytometry.

Results

[¹⁸F]AlF-mNOTA-GZP tumor uptake was able to clearly differentiate treatment responders from non-responders when stratified based on changes in tumor volume. Furthermore, [¹⁸F]AlF-mNOTA-GZP showed positive associations with changes in tumor-associated lymphocytes expressing GZB, namely GZB+ CD8+ T cells and GZB+ NK+ cells.

Conclusions

[¹⁸F]AlF-mNOTA-GZP tumor uptake, driven by changes in immune cell populations expressing GZB, is able to stratify tumor response to chemotherapeutics combined with ICIs. Our results show that, while the immunomodulatory mode of action of the chemotherapies may be different, the ultimate mechanism of tumor lysis through release of Granzyme B is an accurate biomarker for treatment response.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11307-021-01596-y.

Cytokine Profiling of End Stage Cancer Patients Treated with Immunotherapy

Published data suggest that immunotherapy plays a role even in patients with very advanced tumours. We investigated the immune profile of end-stage cancer patients treated with immunotherapy to identify changes induced by treatment. Breast, colon, renal and prostate cancer patients were eligible. Treatment consisted of metronomic cyclophosphamide, low-dose interleukin-2 (IL-2) and a single radiation shot. A panel of 16 cytokines was assessed using automated ELISA before treatment (T0), after radiation (RT; T1), at cycle 2 (T2) and at disease progression (TPD). Receiving operating characteristic (ROC) analysis was used to identify cytokine cut-off related to overall survival (OS). Principal component analysis (PCA) was used to identify the immune profile correlating better with OS and progression-free survival. Twenty-three patients were enrolled. High IL-2, low IL-8 and CCL-2 correlated with OS. The PCA identified a cluster of patients, with high IL-2, IL-12 and IFN-γ levels at T0 having longer PFS and OS. In all cohorts, IL-2 and IL-5 increased from T0 to T2; a higher CCL-4 level compared to T2 and a higher IL-8 level compared to T0 were found at TPD. The progressive increase of the IL-10 level during treatment negatively correlated with OS. Our data suggested that baseline cytokine levels may predict patients’ outcome and that the treatment may affect their kinetic even in end-stage patients. Cytokine profiling of end-stage patients might offer a tool for medical decisions (EUDRACT: 2016-000578-39).

Opportunities and Challenges in Drug Development for Pediatric Cancers

The use of targeted small-molecule therapeutics and immunotherapeutics has been limited to date in pediatric oncology. Recently, the number of pediatric approvals has risen, and regulatory initiatives in the United States and Europe have aimed to increase the study of novel anticancer therapies in children. Challenges of drug development in children include the rarity of individual cancer diagnoses and the high prevalence of difficult-to-drug targets, including transcription factors and epigenetic regulators. Ongoing pediatric adaptation of biomarker-driven trial designs and further exploration of agents targeting non-kinase drivers constitute high-priority objectives for future pediatric oncology drug development. SIGNIFICANCE: Increasing attention to drug development for children with cancer by regulators and pharmaceutical companies holds the promise of accelerating the availability of new therapies for children with cancer, potentially improving survival and decreasing the acute and chronic toxicities of therapy. However, unique approaches are necessary to study novel therapies in children that take into account low patient numbers, the pediatric cancer genomic landscape and tumor microenvironment, and the need for pediatric formulations. It is also critical to evaluate the potential for unique toxicities in growing hosts without affecting the pace of discovery for children with these life-threatening diseases.

Combination Chemo-Immunotherapy for Pancreatic Cancer Using the Immunogenic Effects of an Irinotecan Silicasome Nanocarrier Plus Anti-PD-1

There is an urgent need to develop new life-prolonging therapy for pancreatic ductal adenocarcinoma (PDAC). It is demonstrated that improved irinotecan delivery by a lipid bilayer coated mesoporous silica nanoparticle, also known as a silicasome, can improve PDAC survival through a chemo-immunotherapy response in an orthotopic Kras-dependent pancreatic cancer model. This discovery is premised on the weak-basic properties of irinotecan, which neutralizes the acidic lysosomal pH in PDAC cells. This effect triggers a linked downstream cascade of events that include autophagy inhibition, endoplasmic reticulum stress, immunogenic cell death (ICD), and programmed death-ligand 1 (PD-L1) expression. ICD is characterized by calreticulin expression and high-mobility group box 1 (HMGB1) release in dying Kras-induced pancreatic cancer (KPC) cells, which is demonstrated in a vaccination experiment to prevent KPC tumor growth on the contralateral site. The improved delivery of irinotecan by the silicasome is accompanied by robust antitumor immunity, which can be synergistically enhanced by anti-PD-1 in the orthotopic model. Immunophenotyping confirms the expression of calreticulin, HMGB1, PD-L1, and an autophagy marker, in addition to perforin and granzyme B deposition. The chemo-immunotherapy response elicited by the silicasome is more robust than free or a liposomal drug, Onivyde. The silicasome plus anti-PD-1 leads to significantly enhanced survival improvement, and is far superior to anti-PD-1 plus either free irinotecan or Onivyde.

Efficacy and safety of anti-PD-1/PD-L1 combinations versus standard of care in cancer: a systematic review and meta-analysis

Immune checkpoint inhibitors (ICIs) as monotherapy in different solid tumors showed an early detrimental effect in a subset of patients reflected by the early crossover of the progression-free survival (PFS) curves. Currently, combination therapies with ICIs added to chemotherapy or targeted therapy are expanding the landscape of metastatic solid tumors. We have examined the benefits and risks of adding ICIs to the standard of care (SOC) versus SOC alone.

A search of randomized clinical trials (RCTs) comparing ICIs combinations versus the corresponding SOC in different metastatic tumors according to the PRISMA guidelines was performed. Selected endpoints included PFS, time-to-response (TTR), overall survival (OS), overall response rate (ORR), and ≥ grade 3 adverse events (AEs). Subgroup analyses based on backbone treatment and tumor type were included.

A total of 10536 patients (19 studies) were included (ICIs-arm: 5596 patients; SOC-arm: 4940 patients). Globally, PFS, OS, and ORR results favored ICIs-arm. No differences in terms of TTR were found between arms. ICI-arm was associated with a slight increase of ≥ G3 AEs (relative risk: 1.07). The results in multiple myeloma patients are controversial in favor of ICIs combinations.

Adding ICIs to SOC benefits a greater number of patients, prolonging survival with no early detrimental effect. The toxicity profile is safe, with a mild increase of high-grade manageable AEs.

Emerging Immunotherapy for Acute Myeloid Leukemia

Several immune checkpoint molecules and immune targets in leukemic cells have been investigated. Recent studies have suggested the potential clinical benefits of immuno-oncology (IO) therapy against acute myeloid leukemia (AML), especially targeting CD33, CD123, and CLL-1, as well as immune checkpoint inhibitors (e.g., anti-PD (programmed cell death)-1 and anti-CTLA4 (cytotoxic T-lymphocyte-associated protein 4) antibodies) with or without conventional chemotherapy. Early-phase clinical trials of chimeric antigen receptor (CAR)-T or natural killer (NK) cells for relapsed/refractory AML showed complete remission (CR) or marked reduction of marrow blasts in a few enrolled patients. Bi-/tri-specific antibodies (e.g., bispecific T-cell engager (BiTE) and dual-affinity retargeting (DART)) exhibited 11-67% CR rates with 13-78% risk of cytokine-releasing syndrome (CRS). Conventional chemotherapy in combination with anti-PD-1/anti-CTLA4 antibody for relapsed/refractory AML showed 10-36% CR rates with 7-24 month-long median survival. The current advantages of IO therapy in the field of AML are summarized herein. However, although cancer vaccination should be included in the concept of IO therapy, it is not mentioned in this review because of the paucity of relevant evidence.

Tumor Heterogeneity: A Great Barrier in the Age of Cancer Immunotherapy

Throughout the history of oncology research, tumor heterogeneity has been a major hurdle for the successful treatment of cancer. As a result of aberrant changes in the tumor microenvironment such as high mutational burden, hypoxic conditions and abnormal vasculature, several malignant subpopulations often exist within a single tumor mass. Therapeutic intervention can also increase selective pressure towards subpopulations with acquired resistance. This phenomenon is often the cause of relapse in previously responsive patients, drastically changing the expected outcome of therapy. In the case of cancer immunotherapy, tumor heterogeneity is a substantial barrier as acquired resistance often takes the form of antigen escape and immunosuppression. In an effort to combat intrinsic resistance mechanisms, therapies are often combined as a multi-pronged approach to target multiple pathways simultaneously. These multi-therapy regimens have long been a mainstay of clinical oncology with chemotherapy cocktails but are more recently being investigated in the emerging landscape of immunotherapy. Furthermore, as high throughput technology becomes more affordable and accessible, researchers continue to deepen their understanding of the factors that influence tumor heterogeneity and shape the TME over the course of treatment regimens. In this review, we will investigate the factors that give rise to tumor heterogeneity and the impact it has on the field of immunotherapy. We will discuss how tumor heterogeneity causes resistance to various treatments and review the strategies currently being employed to overcome this challenging clinical hurdle. Finally, we will outline areas of research that should be prioritized to gain a better understanding of tumor heterogeneity and develop appropriate solutions.

Peripheral blood T-cell receptor repertoire as a predictor of clinical outcomes in gastrointestinal cancer patients treated with PD-1 inhibitor

BACKGROUND

Identifying valid biomarkers for patient selection impressively promotes the success of anti-PD-1 therapy. However, the unmet need for biomarkers in gastrointestinal (GI) cancers remains significant. We aimed to explore the predictive value of the circulating T-cell receptor (TCR) repertoire for clinical outcomes in GI cancers who received anti-PD-1 therapy.

METHODS

137 pre- and 79 post-treated peripheral blood samples were included. The TCR repertoire was evaluated by sequencing of complementarity-determining region 3 (CDR3) in the TRB gene. The Shannon index was used to measure the diversity of the TCR repertoire, and Morisita's overlap index was used to determine TCR repertoire similarities between pre- and post-treated samples.

RESULTS

Among all enrolled patients, 76 received anti-PD-1 monotherapy and 61 received anti-PD-1 combination therapy. In the anti-PD-1 monotherapy cohort, patients with higher baseline TCR diversity exhibited a significantly higher disease control rate (77.8% vs. 47.2%; hazard ratio [HR] 3.92; 95% confidence interval [CI] 1.14-13.48; P = 0.030) and a longer progression-free survival (PFS) (median: 6.47 months vs. 2.77 months; HR 2.10; 95% CI 1.16-3.79; P = 0.014) and overall survival (OS) (median: NA vs. 8.97 months; HR 3.53; 95% CI 1.49-8.38; P = 0.004) than those with lower diversity. Moreover, patients with a higher TCR repertoire similarity still showed a superior PFS (4.43 months vs. 1.84 months; HR 13.98; 95% CI 4.37-44.68; P < 0.001) and OS (13.40 months vs. 6.12 months; HR 2.93; 95% CI 1.22-7.03; P = 0.016) even in the cohort with lower baseline diversity. However, neither biomarker showed predictive value in the anti-PD-1 combination therapy cohort. Interestingly, the combination of TCR diversity and PD-L1 expression can facilitate patient stratification in a pooled cohort.

CONCLUSION

The circulating TCR repertoire can serve as a predictor of clinical outcomes in anti-PD-1 therapy in GI cancers.

Chemotherapeutic and targeted agents can modulate the tumor microenvironment and increase the efficacy of immune checkpoint blockades

The development of immune checkpoint blockade (ICB)-based immunotherapy has dramatically changed methods of cancer treatment. This approach triggers a durable treatment response and prolongs patients' survival; however, not all patients can benefit. Accumulating evidence demonstrated that the efficacy of ICB is dependent on a robust antitumor immune response that is usually damaged in most tumors. Conventional chemotherapy and targeted therapy promote the antitumor immune response by increasing the immunogenicity of tumor cells, improving CD8+ T cell infiltration, or inhibiting immunosuppressive cells in the tumor microenvironment. Such immunomodulation provides a convincing rationale for the combination therapy of chemotherapeutics and ICBs, and both preclinical and clinical investigations have shown encouraging results. However, the optimal drug combinations, doses, timing, and sequence of administration, all of which affect the immunomodulatory effect of chemotherapeutics, as well as the benefit of combination therapy, are not yet determined. Future studies should focus on these issues and help to develop the optimal combination regimen for each cancer.

KEYNOTE-975 study design: a Phase III study of definitive chemoradiotherapy plus pembrolizumab in patients with esophageal carcinoma

Despite curative-intent treatment, most patients with locally advanced esophageal cancer will experience disease recurrence or locoregional progression, highlighting the need for new therapies. Current guidelines recommend definitive chemoradiotherapy in patients ineligible for surgical resection, but survival outcomes are poor. Pembrolizumab is well tolerated and provides promising antitumor activity in patients with previously treated, advanced, unresectable esophageal/esophagogastric junction cancer. Combining pembrolizumab with chemoradiotherapy may further improve outcomes in the first-line setting. Here, we describe the design and rationale for the double-blind, Phase III, placebo-controlled, randomized KEYNOTE-975 trial investigating pembrolizumab in combination with definitive chemoradiotherapy as first-line treatment in patients with locally advanced, unresectable esophageal/gastroesophageal junction cancer. Overall survival and event-free survival are the dual primary end points.

Clinical trial registration: NCT04210115 (ClinicalTrials.gov)

Evaluation of the Safety and Efficacy of Immunotherapy Rechallenge in Patients With Renal Cell Carcinoma

Importance

Several immune checkpoint inhibitors (ICIs) are approved for use in patients with metastatic renal cell carcinoma (mRCC), but the efficacy and safety of ICI rechallenge in mRCC is unknown.

Objective

To evaluate the safety and efficacy of ICI rechallenge in patients with mRCC.

Design, Setting, and Participants

This multicenter, retrospective cohort study included consecutive patients with mRCC from 9 institutions in the US who received at least 2 separate lines of ICI (ICI-1, ICI-2) between January 2012 and December 2019.

Exposure

Receipt of an ICI (anticytotoxic T-lymphocyte-associated protein 4, anti-programmed cell death protein 1, or anti-programmed cell death ligand 1), alone or in combination with other therapies, in at least 2 separate lines of therapy for mRCC.

Main Outcomes and Measures

Investigator-assessed best overall response and immune-related adverse events.

Results

A total of 69 patients were included. Median (range) age at diagnosis of mRCC was 61 (36-86) years. Of these, 50 were men and 19 were women. The most common therapies received at ICI-1 were single-agent ICI (n = 27 [39%]) or ICI in combination with targeted therapy (n = 29 [42%]), while at ICI-2, the most common therapies were single-agent ICI (n = 26 [38%]) or dual ICI (n = 22 [32%]). Most patients discontinued ICI-1 owing to disease progression (n = 50 [72%]) or toxic effects (n = 16 [23%]). The overall response rates at ICI-1 and ICI-2 were 37% and 23%, respectively. The likelihood of a response at ICI-2 was greatest among patients who had previously responded to ICI-1 (7 of 24 [29%]), although responses at ICI-2 were seen in those who had progressive disease as their best response following ICI-1 (3 of 14 [21%]) as well as in those who received single-agent ICI at ICI-2 (7 of 23 [30%]). Grade 3 or higher immune-related adverse events were seen in 18 patients (26%) and 11 patients (16%) at ICI-1 and ICI-2, respectively. There were no treatment-related deaths.

Conclusions and Relevance

The findings of this multicenter cohort study suggest that ICI rechallenge in patients with mRCC may be safe and reasonably efficacious, with an overall response rate of 23%. Data from prospective studies are needed to validate these findings and determine the role of sequential ICI regimens in treatment of mRCC.

Intratumoral expression of IL-7 and IL-12 using an oncolytic virus increases systemic sensitivity to immune checkpoint blockade

The immune status of the tumor microenvironment is a key indicator in determining the antitumor effectiveness of immunotherapies. Data support the role of activation and expansion of tumor-infiltrating lymphocytes (TILs) in increasing the benefit of immunotherapies in patients with solid tumors. We found that intratumoral injection of a tumor-selective oncolytic vaccinia virus encoding interleukin-7 (IL-7) and IL-12 into tumor-bearing immunocompetent mice activated the inflammatory immune status of previously poorly immunogenic tumors and resulted in complete tumor regression, even in distant tumor deposits. Mice achieving complete tumor regression resisted rechallenge with the same tumor cells, suggesting establishment of long-term tumor-specific immune memory. Combining this virotherapy with anti-programmed cell death-1 (PD-1) or anti-cytotoxic T lymphocyte antigen 4 (CTLA4) antibody further increased the antitumor activity as compared to virotherapy alone, in tumor models unresponsive to either of the checkpoint inhibitor monotherapies. These findings suggest that administration of an oncolytic vaccinia virus carrying genes encoding for IL-7 and IL-12 has antitumor activity in both directly injected and distant noninjected tumors through immune status changes rendering tumors sensitive to immune checkpoint blockade. The benefit of intratumoral IL-7 and IL-12 expression was also observed in humanized mice bearing human cancer cells. These data support further investigation in patients with non-inflamed solid tumors.

Neoadjuvant Chemoradiotherapy Combined with Atezolizumab for Resectable Esophageal Adenocarcinoma: A Single-arm Phase II Feasibility Trial (PERFECT)

PURPOSE

The CROSS trial established neoadjuvant chemoradiotherapy (nCRT) for patients with resectable esophageal adenocarcinoma (rEAC). In the PERFECT trial, we investigated the feasibility and efficacy of nCRT combined with programmed-death ligand-1 (PD-L1) inhibition for rEAC.

PATIENTS AND METHODS

Patients with rEAC received nCRT according to the CROSS regimen combined with five cycles of atezolizumab (1,200 mg). The primary endpoint was the feasibility of administering five cycles of atezolizumab in ≥75% patients. A propensity score-matched nCRT cohort was used to compare pathologic response, overall survival, and progression-free survival. Exploratory biomarker analysis was performed on repeated tumor biopsies.

RESULTS

We enrolled 40 patients of whom 85% received all cycles of atezolizumab. Immune-related adverse events of any grade were observed in 6 patients. In total, 83% proceeded to surgery. Reasons for not undergoing surgery were progression (n = 4), patient choice (n = 2), and death (n = 1). The pathologic complete response rate was 25% (10/40). No statistically significant difference in response or survival was found between the PERFECT and the nCRT cohort. Baseline expression of an established IFNγ signature was higher in responders compared with nonresponders (P = 0.043). On-treatment nonresponders showed either a high number of cytotoxic lymphocytes (CTL) with a transcriptional signature consistent with expression of immune checkpoints, or a low number of CTLs.

CONCLUSIONS

Combining nCRT with atezolizumab is feasible in patients with rEAC. On the basis of our exploratory biomarker study, future studies are necessary to elucidate the potential of neoadjuvant immunotherapy in patient subgroups.See related commentary by Catenacci, p. 3269.

Arginase Therapy Combines Effectively with Immune Checkpoint Blockade or Agonist Anti-OX40 Immunotherapy to Control Tumor Growth

Metabolic dysregulation is a hallmark of cancer. Many tumors exhibit auxotrophy for various amino acids, such as arginine, because they are unable to meet the demand for these amino acids through endogenous production. This vulnerability can be exploited by employing therapeutic strategies that deplete systemic arginine in order to limit the growth and survival of arginine auxotrophic tumors. Pegzilarginase, a human arginase-1 enzyme engineered to have superior stability and enzymatic activity relative to the native human arginase-1 enzyme, depletes systemic arginine by converting it to ornithine and urea. Therapeutic administration of pegzilarginase in the setting of arginine auxotrophic tumors exerts direct antitumor activity by starving the tumor of exogenous arginine. We hypothesized that in addition to this direct effect, pegzilarginase treatment indirectly augments antitumor immunity through increased antigen presentation, thus making pegzilarginase a prime candidate for combination therapy with immuno-oncology (I-O) agents. Tumor-bearing mice (CT26, MC38, and MCA-205) receiving pegzilarginase in combination with anti-PD-L1 or agonist anti-OX40 experienced significantly increased survival relative to animals receiving I-O monotherapy. Combination pegzilarginase/immunotherapy induced robust antitumor immunity characterized by increased intratumoral effector CD8⁺ T cells and M1 polarization of tumor-associated macrophages. Our data suggest potential mechanisms of synergy between pegzilarginase and I-O agents that include increased intratumoral MHC expression on both antigen-presenting cells and tumor cells, and increased presence of M1-like antitumor macrophages. These data support the clinical evaluation of I-O agents in conjunction with pegzilarginase for the treatment of patients with cancer.

The Periphery of Salivary Gland Carcinoma Tumors Reveals a PD-L1/PD-1 Biomarker Niche for the Evaluation of Disease Severity and Tumor-Immune System Interplay

The treatment options for patients with advanced salivary gland cancers (SGCs) are limited. Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment. However, the response to ICI immunotherapy is largely driven by the immune cell signatures within the tumor tissue and the para-tumoral tissue compartments. To date, there are no data on the expression of programed cell death protein-1/programed cell death protein-ligand 1 (PD-1/PD-L1) in SGC, which may enable the implementation of ICI immunotherapy for this disease. Thus, we performed an immunohistochemical analysis of PD-1 and PD-L1 expression in tumor cells and tumor-infiltrating immune cells (TIICs) in the tumor center and periphery of 62 SGC patients. The tumor periphery showed significantly higher expression of PD-L1 in tumor cells than in TIICs. Moreover, peripheral TIICs had significantly higher PD-1 expression than peripheral tumor cells. PD-1-positive tumor cells were detected exclusively in the tumor center of high-grade tumors, and most importantly, the presence of lymph node (LN) metastases and primary tumor stage significantly correlated with the presence of PD-L1-positive tumor cells in the tumor periphery. The PD-1/PD-L1 molecular signatures in SGC are clustered predominantly in the tumor periphery, reflect disease severity, and may predict the response to ICI immunotherapy in SGC patients.

The right Timing, right combination, right sequence, and right delivery for Cancer immunotherapy

Cancer immunotherapy (CI) represented by immune checkpoint inhibitors (ICIs) presents a new paradigm for cancer treatment. However, the types of cancer that attain a therapeutic benefit from ICIs are limited, and the efficacy of these treatments does not meet expectations. To date, research on ICIs has mainly focused on identifying biomarkers and patient characteristics that can enhance the therapeutic effect on tumors. However, studies on combinational strategies for CI are being actively conducted to overcome the resistance to ICI treatment. Moreover, it has been confirmed that dramatic anticancer effects are achieved through "neoadjuvant" immunotherapy with ICIs in treatment-naïve cancer patients; consequently, it has become necessary to consider how to best apply cancer immunotherapies for patients, even with respect to their tumor stages. In this review, we sought to discuss the right timing of ICI treatment in consideration of the progression of cancer with a changing tumor-immune microenvironment. Furthermore, we investigated which types of combinational treatments and their corresponding sequences of administration could optimize the therapeutic effect of ICIs to expand the applicable target of ICIs and increase their therapeutic efficacy. Finally, we discussed several delivery pathways and methods that can maximize the effect of ICIs.

Combined immune checkpoint blockade increases CD8+CD28+PD-1+ effector T cells and provides a therapeutic strategy for patients with neuroblastoma

Immune checkpoint therapy has resulted in minimal clinical response in many pediatric cancers. We sought to understand the influence of immune checkpoint inhibition using anti-PD-1 and anti-CTLA-4 antibodies individually, in combination, and after chemotherapy on immune responses in minimal and established murine neuroblastoma models. We also sought to understand the role of the tumor microenvironment (TME) and PD-L1 expression and their alteration post-chemotherapy in our models and human tissues. PD-L1 expression was enriched in human tumor-associated macrophages and up-regulated after chemotherapy. In a murine minimal disease model, single and dual immune checkpoint blockade promoted tumor rejection, improved survival, and established immune memory with long-term anti-tumor immunity against re-challenge. In an established tumor model, only dual immune checkpoint blockade showed efficacy. Interestingly, dual immune checkpoint therapy distinctly influenced adaptive and innate immune responses, with significant increase in CD8⁺CD28⁺PD-1⁺ T cells and inflammatory macrophages (CD11b^hiCD11c⁻F4/80⁺Ly6C^hi) in tumor-draining lymph nodes. Adding chemotherapy before immunotherapy provided significant survival benefit for mice with established tumors receiving anti-PD-1 or dual immune checkpoint blockade. Our findings demonstrate anti-PD-1 and anti-CTLA-4 therapy induces a novel subset of effector T cells, and support administration of induction chemotherapy immediately prior to immune checkpoint blockade in children with high-risk neuroblastoma.

The role of nivolumab combined to immunotherapy and/or chemotherapy in the first-line treatment of advanced Non Small Cell Lung Cancer

Introduction: One of the latest breakthroughs in the treatment of advanced Non Small Cell Lung Cancer (NSCLC) is represented by PD-1/PD-L1-targeting Immune Checkpoint Inhibitors (ICIs). However, only a limited subset of advanced NSCLC patients can receive first-line ICI monotherapy (advanced NSCLC patients without driver mutations and with a PD-L1 expression ≥50% or ≥1%) and naïve ICI-respondent patients represent an even more limited subgroup of patients, which eventually experience progression of disease after approximately 7-11 months. Therefore, different strategies are being evaluated to obtain a higher response rate and a more durable clinical response in this setting. A very encouraging one is represented by ICI-combination therapies, i.e. the use of an ICI combined to cytotoxic chemotherapy and/or another immunotherapeutic agent.Areas covered: This paper aims to assess currently available data from trials evaluating nivolumab-based first-line combination therapies.Expert opinion: Nivolumab-based combinations regimens will represent one of the standard treatments for naïve advanced NSCLC patients in a near future. However, in order to fully exploit these combination therapies, additional studies assessing potential predictive and/or prognostic biomarkers are required to better clarify which patients are more likely to benefit from these regimens, alongside with studies investigating safer and more durable second-line treatments.

Heterogeneous Tumor-Immune Microenvironments between Primary and Metastatic Tumors in a Patient with ALK Rearrangement-Positive Large Cell Neuroendocrine Carcinoma

Evolution of tumor-immune microenviroments (TIMEs) occurs during tumor growth and dissemination. Understanding inter-site tumor-immune heterogeneity is essential to harness the immune system for cancer therapy. While the development of immunotherapy against lung cancer with driver mutations and neuroendocrine tumors is ongoing, little is known about the TIME of large cell neuroendocrine carcinoma (LCNEC) or anaplastic lymphoma kinase (ALK) rearrangement-positive lung cancer. We present a case study of a 32-year-old female patient with ALK-rearrangement-positive LCNEC, who had multiple distant metastases including mediastinal lymph-node, bilateral breasts, multiple bones, liver and brain. Multiple biopsy samples obtained from primary lung and three metastatic tumors were analyzed by fluorescent multiplex immunohistochemistry. Tissue localizations of tumor-infiltrating lymphocytes in the tumor nest and surrounding stroma were evaluated. T cell and B cell infiltrations were decreased with distance from primary lung lesion. Although each tumor displayed a unique TIME, all tumors exhibited concomitant regression after treatment with an ALK-inhibitor. This study provides the first evidence of the coexistence of distinct TIME within a single individual with ALK-rearrangement-positive LCNEC. The present study contributes to our understanding of heterogeneous TIMEs between primary and metastatic lesions and provides new insights into the complex interplay between host-immunity and cancer cells in primary and metastatic lesions.

The therapeutic significance of the novel photodynamic material TPE-IQ-2O in tumors

Combination therapies based on photodynamic therapy (PDT) have received much attention in various cancers due to their strong therapeutic effects. Here, we aimed to explore the safety and effectiveness of a new mitochondria-targeting photodynamic material, TPE-IQ-2O, in combination therapies (combined with surgery or immunotherapy). The safety and effectiveness of TPE-IQ-2O PDT were verified with cytotoxicity evaluation in vitro and a zebrafish xenograft model in vivo, respectively. The effectiveness of TPE-IQ-2O PDT combined with surgery or immune checkpoint inhibitors (ICIs) was verified in tumor-bearing mice. Small animal in vivo imaging, immunohistochemistry, and flow cytometry were used to determine the underlying mechanism. TPE-IQ-2O PDT can not only reduce tumor recurrence in surgical treatment but also effectively improve the response to ICIs in immunotherapy without obvious toxicity. It was also found to ameliorate the immunosuppressive tumor microenvironment and promote the antitumor immunity induced by ICIs by increasing CD8⁺ tumor-infiltrating lymphocyte accumulation. Thus, TPE-IQ-2O PDT is a safe and effective antitumor therapy that can be combined with surgery or immunotherapy.

High-intensity statins are associated with improved clinical activity of PD-1 inhibitors in malignant pleural mesothelioma and advanced non-small cell lung cancer patients

BACKGROUND

In preclinical models, statins showed vaccine adjuvant activities and synergized with PD-1 inhibitors. We analyzed the impact of statin treatment on clinical outcome in thoracic cancer patients treated with PD-1 inhibitors.

METHODS

A total of 82 malignant pleural mesothelioma (MPM) and 179 advanced non-small cell lung cancer (aNSCLC) patients treated with PD-1 inhibitors as second or further line treatment were examined. Seventy-seven MPM patients treated with standard chemotherapy were analyzed as control cohort. Objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were calculated.

RESULTS

Among 253 patients with available data, statin use was associated with increased ORR (32% versus 18%, P = .02), PFS (median 6.7 versus 2.9 months, hazard ratio [HR] 0.57, 95% CI 0.39-0.83, P < .01), and OS (median 13.1 versus 8.7 months, HR 0.67, 95% CI 0.45-1.00, P = .05). In the control MPM cohort treated with chemotherapy (n = 77), no association was found. MPM patients who used statins showed improved ORR (22% versus 6%, P = .05), PFS (median 6.7 versus 2.4 months, P < .01), and OS (median not reached versus 6.0 months, P = .01). In aNSCLC patients, statin use was associated with improved ORR (40% versus 22%, P = .04) and PFS (median 7.8 versus 3.6 months, P = .03), but no significant difference in OS was found (median 13.1 versus 10.1 months, P = .30). Multivariable analysis confirmed the correlation between statin use and better PFS and OS in MPM and better PFS in aNSCLC. In the whole cohort, high but not low/moderate-intensity statins were associated with better OS compared to no user (P = .02 and P = .59, respectively).

CONCLUSIONS

Our study showed that statins are associated with better clinical outcome in MPM and aNSCLC patients treated with PD-1 inhibitors in an intensity-dependent manner.

Predictive Biomarkers for Immune Checkpoint Inhibitors in Advanced Non-Small Cell Lung Cancer: Current Status and Future Directions

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment paradigm for advanced non-small cell lung cancer (NSCLC). Although certain patients achieve significant, long-lasting responses from checkpoint blockade, the majority of patients with NSCLC do not and may be unnecessarily exposed to inadequate therapies and immune-related toxicities. Therefore, there is a critical need to identify biomarkers predictive of immunotherapy response. While tumor and immune cell expression of programmed death ligand-1 and, more recently, tumor mutational burden are used in clinical practice and may correlate with immunotherapy response in selected circumstances, neither consistently predicts an individual patient's likelihood of clinical benefit from ICI therapy. More recently, innovative approaches such as blood-based assays and combination biomarker strategies are under active investigation. This review will focus on the current role and challenges of programmed death ligand-1 and tumor mutational burden as predictive biomarkers for immunotherapy response in advanced NSCLC and explore promising novel biomarker strategies.

Immunotherapy for early breast cancer: too soon, too superficial, or just right?

Immunotherapy emerged as a new treatment modality for breast cancer, and its use is approved in combination with chemotherapy for first-line therapy in metastatic triple-negative breast cancer overexpressing PD-L1. As immune checkpoint inhibitors alone have modest clinical activity in advanced breast cancer, there is a growing interest in combinatorial modalities, and particularly for their rapid development in the early disease setting. The plethora of ongoing immunotherapy trials in early breast cancer comes at a time when solid data in advanced disease are still imperfect. This review offers a perspective on the efforts to establish the efficacy and safety of immunotherapeutic agents in early breast cancer.

Antitumor Drugs and Their Targets

Through novel methodologies, including both basic and clinical research, progress has been made in the therapy of solid cancer. Recent innovations in anticancer therapies, including immune checkpoint inhibitor biologics, therapeutic vaccines, small drugs, and CAR-T cell injections, mark a new epoch in cancer research, already known for faster (epi-)genomics, transcriptomics, and proteomics. As the long-sought after personalization of cancer therapies comes to fruition, the need to evaluate all current therapeutic possibilities and select the best for each patient is of paramount importance. This is a novel task for medical care that deserves prominence in therapeutic considerations in the future. This is because cancer is a complex genetic disease. In its deadly form, metastatic cancer, it includes altered genes (and their regulators) that encode ten hallmarks of cancer-independent growth, dodging apoptosis, immortalization, multidrug resistance, neovascularization, invasiveness, genome instability, inflammation, deregulation of metabolism, and avoidance of destruction by the immune system. These factors have been known targets for many anticancer drugs and treatments, and their modulation is a therapeutic goal, with the hope of rendering solid cancer a chronic rather than deadly disease. In this article, the current therapeutic arsenal against cancers is reviewed with a focus on immunotherapies.

The Dichotomous Role of Bone Marrow Derived Cells in the Chemotherapy-Treated Tumor Microenvironment

Bone marrow derived cells (BMDCs) play a wide variety of pro- and anti-tumorigenic roles in the tumor microenvironment (TME) and in the metastatic process. In response to chemotherapy, the anti-tumorigenic function of BMDCs can be enhanced due to chemotherapy-induced immunogenic cell death. However, in recent years, a growing body of evidence suggests that chemotherapy or other anti-cancer drugs can also facilitate a pro-tumorigenic function in BMDCs. This includes elevated angiogenesis, tumor cell proliferation and pro-tumorigenic immune modulation, ultimately contributing to therapy resistance. Such effects do not only contribute to the re-growth of primary tumors but can also support metastasis. Thus, the delicate balance of BMDC activities in the TME is violated following tumor perturbation, further requiring a better understanding of the complex crosstalk between tumor cells and BMDCs. In this review, we discuss the different types of BMDCs that reside in the TME and their activities in tumors following chemotherapy, with a major focus on their pro-tumorigenic role. We also cover aspects of rationally designed combination treatments that target or manipulate specific BMDC types to improve therapy outcomes.

Augmenting Anticancer Immunity Through Combined Targeting of Angiogenic and PD-1/PD-L1 Pathways: Challenges and Opportunities

Cancer immunotherapy (CIT) with antibodies targeting the programmed cell death 1 protein (PD-1)/programmed cell death 1 ligand 1 (PD-L1) axis have changed the standard of care in multiple cancers. However, durable antitumor responses have been observed in only a minority of patients, indicating the presence of other inhibitory mechanisms that act to restrain anticancer immunity. Therefore, new therapeutic strategies targeted against other immune suppressive mechanisms are needed to enhance anticancer immunity and maximize the clinical benefit of CIT in patients who are resistant to immune checkpoint inhibition. Preclinical and clinical studies have identified abnormalities in the tumor microenvironment (TME) that can negatively impact the efficacy of PD-1/PD-L1 blockade. Angiogenic factors such as vascular endothelial growth factor (VEGF) drive immunosuppression in the TME by inducing vascular abnormalities, suppressing antigen presentation and immune effector cells, or augmenting the immune suppressive activity of regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages. In turn, immunosuppressive cells can drive angiogenesis, thereby creating a vicious cycle of suppressed antitumor immunity. VEGF-mediated immune suppression in the TME and its negative impact on the efficacy of CIT provide a therapeutic rationale to combine PD-1/PD-L1 antibodies with anti-VEGF drugs in order to normalize the TME. A multitude of clinical trials have been initiated to evaluate combinations of a PD-1/PD-L1 antibody with an anti-VEGF in a variety of cancers. Recently, the positive results from five Phase III studies in non-small cell lung cancer (adenocarcinoma), renal cell carcinoma, and hepatocellular carcinoma have shown that combinations of PD-1/PD-L1 antibodies and anti-VEGF agents significantly improved clinical outcomes compared with respective standards of care. Such combinations have been approved by health authorities and are now standard treatment options for renal cell carcinoma, non-small cell lung cancer, and hepatocellular carcinoma. A plethora of other randomized studies of similar combinations are currently ongoing. Here, we discuss the principle mechanisms of VEGF-mediated immunosuppression studied in preclinical models or as part of translational clinical studies. We also discuss data from recently reported randomized clinical trials. Finally, we discuss how these concepts and approaches can be further incorporated into clinical practice to improve immunotherapy outcomes for patients with cancer.

Cancer Immunotherapy Dosing: A Pharmacokinetic/Pharmacodynamic Perspective

Immune check-point inhibitors are drugs that are markedly different from other anticancer drugs because of their indirect mechanisms of antitumoral action and their apparently random effect in terms of efficacy and toxicity. This marked pharmacodynamics variability in patients calls for reconsidering to what extent approved dosing used in clinical practice are optimal or whether they should require efforts for customization in outlier patients. To better understand whether or not dosing could be an actionable item in oncology, in this review, preclinical and clinical development of immune checkpoint inhibitors are described, particularly from the angle of dose finding studies. Other issues in connection with dosing issues are developed, such as the flat dosing alternative, the putative role therapeutic drug monitoring could play, the rise of combinatorial strategies, and pharmaco-economic aspects.

Upfront dose-reduced chemotherapy synergizes with immunotherapy to optimize chemoimmunotherapy in squamous cell lung carcinoma

Background

The survival benefits of combining chemotherapy (at the maximum tolerated dose, MTD) with concurrent immunotherapy, collectively referred to as chemoimmunotherapy, for the treatment of squamous cell lung carcinoma (SQCLC) have been confirmed in recent clinical trials. Nevertheless, optimization of chemoimmunotherapy in order to enhance the efficacy of immune checkpoint inhibitors (ICIs) in SQCLC remains to be explored.

Methods

Cell lines, syngeneic immunocompetent mouse models, and patients’ peripheral blood mononuclear cells were used in order to comprehensively explore how to enhance ectopic lymphoid-like structures (ELSs) and upregulate the therapeutic targets of anti-programmed death 1 (PD-1)/anti-PD-1 ligand (PD-L1) monoclonal antibodies (mAbs), thus rendering SQCLC more sensitive to ICIs. In addition, molecular mechanisms underlying optimization were characterized.

Results

Low-dose chemotherapy contributed to an enhanced antigen exposure via the phosphatidylinositol 3-kinase/Akt/transcription factor nuclear factor kappa B signaling pathway. Improved antigen uptake and presentation by activated dendritic cells (DCs) was observed, thus invoking specific T cell responses leading to systemic immune responses and immunological memory. In turn, enhanced antitumor ELSs and PD-1/PD-L1 expression was observed in vivo. Moreover, upfront metronomic (low-dose and frequent administration) chemotherapy extended the time window of the immunostimulatory effect and effectively synergized with anti-PD-1/PD-L1 mAbs. A possible mechanism underlying this synergy is the increase of activated type I macrophages, DCs, and cytotoxic CD8⁺ T cells, as well as the maintenance of intestinal gut microbiota diversity and composition. In contrast, when combining routine MTD chemotherapy with ICIs, the effects appeared to be additive rather than synergistic.

Conclusions

We first attempted to optimize chemoimmunotherapy for SQCLC by investigating different combinatorial modes. Compared with the MTD chemotherapy used in current clinical practice, upfront metronomic chemotherapy performed better with subsequent anti-PD-1/PD-L1 mAb treatment. This combination approach is worth investigating in other types of tumors, followed by translation into the clinic in the future.

Loganetin and 5-fluorouracil synergistically inhibit the carcinogenesis of gastric cancer cells via down-regulation of the Wnt/β-catenin pathway

Although most gastrointestinal tumours are sensitive to 5-fluorouracil (5FU), drug resistance is commonly occurred after 5FU therapy in gastric cancer (GC). Loganetin is the primary active compound in Cornus officinali. However, the synergetic effects of loganetin and 5FU on GC remain unknown. Here, we investigated the synergetic effects and the underlying mechanism of loganetin and 5FU on proliferation, stem-like properties, migration, and invasion of GC both in vitro and in vivo. We found that loganetin alone inhibited the proliferation, stem-like properties, migration and invasion of GC cells in vitro. Importantly, the loganetin remarkably enhanced the anti-cancer effect of 5FU on GC cells and the Wnt/β-catenin pathway might be involved in this process. Animal experiments further confirmed the synergistic effects of 5FU and loganetin on inhibiting cell growth and metastasis of GC. These results suggested that loganetin could synergistically increase the effect of 5FU against GC, which sheds light on effective combinational drug strategies for GC treatment.

Implications of metabolism-driven myeloid dysfunctions in cancer therapy

Immune homeostasis is maintained by an adequate balance of myeloid and lymphoid responses. In chronic inflammatory states, including cancer, this balance is lost due to dramatic expansion of myeloid progenitors that fail to mature to functional inflammatory neutrophils, macrophages, and dendritic cells (DCs), thus giving rise to a decline in the antitumor effector lymphoid response. Cancer-related inflammation orchestrates the production of hematopoietic growth factors and cytokines that perpetuate recruitment and activation of myeloid precursors, resulting in unresolved and chronic inflammation. This pathologic inflammation creates profound alterations in the intrinsic cellular metabolism of the myeloid progenitor pool, which is amplified by competition for essential nutrients and by hypoxia-induced metabolic rewiring at the tumor site. Therefore, persistent myelopoiesis and metabolic dysfunctions contribute to the development of cancer, as well as to the severity of a broad range of diseases, including metabolic syndrome and autoimmune and infectious diseases. The aims of this review are to (1) define the metabolic networks implicated in aberrant myelopoiesis observed in cancer patients, (2) discuss the mechanisms underlying these clinical manifestations and the impact of metabolic perturbations on clinical outcomes, and (3) explore new biomarkers and therapeutic strategies to restore immunometabolism and differentiation of myeloid cells towards an effector phenotype to increase host antitumor immunity. We propose that the profound metabolic alterations and associated transcriptional changes triggered by chronic and overactivated immune responses in myeloid cells represent critical factors influencing the balance between therapeutic efficacy and immune-related adverse effects (irAEs) for current therapeutic strategies, including immune checkpoint inhibitor (ICI) therapy.