A clinical development paradigm for cancer vaccines and related biologics

Analysis of physical and biological delivery systems for DNA cancer vaccines and their translation to clinical development

DNA cancer vaccines as an approach in tumor immunotherapy are still being investigated in preclinical and clinical settings. Nevertheless, only a small number of clinical studies have been published so far and are still active. The investigated vaccines show a relatively stable expression in in-vitro transfected cells and may be favorable for developing an immunologic memory in patients. Therefore, DNA vaccines could be suitable as a prophylactic or therapeutic approach against cancer. Due to the low efficiency of these vaccines, the administration technique plays an important role in the vaccine design and its efficacy. These DNA cancer vaccine delivery systems include physical, biological, and non-biological techniques. Although the pre-clinical studies show promising results in the application of the different delivery systems, further studies in clinical trials have not yet been successfully proven.

Mapping Vaccine Names in Clinical Trials to Vaccine Ontology using Cascaded Fine-Tuned Domain-Specific Language Models

Background

Vaccines have revolutionized public health by providing protection against infectious diseases. They stimulate the immune system and generate memory cells to defend against targeted diseases. Clinical trials evaluate vaccine performance, including dosage, administration routes, and potential side effects. ClinicalTrials.gov is a valuable repository of clinical trial information, but the vaccine data in them lacks standardization, leading to challenges in automatic concept mapping, vaccine-related knowledge development, evidence-based decision-making, and vaccine surveillance.

Results

In this study, we developed a cascaded framework that capitalized on multiple domain knowledge sources, including clinical trials, Unified Medical Language System (UMLS), and the Vaccine Ontology (VO), to enhance the performance of domain-specific language models for automated mapping of VO from clinical trials. The Vaccine Ontology (VO) is a community-based ontology that was developed to promote vaccine data standardization, integration, and computer-assisted reasoning. Our methodology involved extracting and annotating data from various sources. We then performed pre-training on the PubMedBERT model, leading to the development of CTPubMedBERT. Subsequently, we enhanced CTPubMedBERT by incorporating SAPBERT, which was pretrained using the UMLS, resulting in CTPubMedBERT + SAPBERT. Further refinement was accomplished through fine-tuning using the Vaccine Ontology corpus and vaccine data from clinical trials, yielding the CTPubMedBERT + SAPBERT + VO model. Finally, we utilized a collection of pre-trained models, along with the weighted rule-based ensemble approach, to normalize the vaccine corpus and improve the accuracy of the process. The ranking process in concept normalization involves prioritizing and ordering potential concepts to identify the most suitable match for a given context. We conducted a ranking of the Top 10 concepts, and our experimental results demonstrate that our proposed cascaded framework consistently outperformed existing effective baselines on vaccine mapping, achieving 71.8% on top 1 candidate's accuracy and 90.0% on top 10 candidate's accuracy.

Conclusion

This study provides a detailed insight into a cascaded framework of fine-tuned domain-specific language models improving mapping of VO from clinical trials. By effectively leveraging domain-specific information and applying weighted rule-based ensembles of different pre-trained BERT models, our framework can significantly enhance the mapping of VO from clinical trials.

Immunotherapies catering to the unmet medical need of cold colorectal cancer

As a common malignant tumor of gastrointestinal tract, the incidence of colorectal cancer (CRC) has gradually increased in recent years. In western developed countries, it has even become the second largest malignant tumor next to lung cancer. Immunotherapy is a hot topic in the field of cancer therapy, including immune checkpoint blockade (ICB), adoptive cell therapy (ACT), cancer vaccines and cytokines, aiming to improve the ability of the immune system to recognize, target and eliminate cancer cells. However, cold CRC, which accounts for a high proportion of CRC, is not so reactive to it. The development of immunotherapy to prevent cancer cells from forming “immune escape” pathways to the immune system in cold CRC, has been under increasing study attention. There is proof that an organic combination of radiotherapy, chemotherapy, and several immunotherapies can considerably boost the immune system’s capacity to eradicate tumor cells. In this review, we summarized the role of immunotherapy in colorectal cancer. In addition, we propose a breakthrough and strategy to improve the role of immunotherapy in cold CRC based on its characteristics.

Versatile tests for window mean survival time

Window mean survival time (WMST) evaluates the mean survival between a lower time horizon, τ 0 $$ {\tau}_0 $$ , and an upper time horizon, τ 1 $$ {\tau}_1 $$ . As a flexible extension of restricted mean survival time, specific clinically relevant windows of time can be assessed for survival difference accompanied by a communicable interpretation of estimates and tests. In its original application, WMST required the pre-specification of a window through the selection of appropriate window bounds, τ 0 $$ {\tau}_0 $$ and τ 1 $$ {\tau}_1 $$ . In the instance of severe window misspecification of τ 0 $$ {\tau}_0 $$ and τ 1 $$ {\tau}_1 $$ , the analysis may suffer from low power and a less meaningful interpretation. In this article, we introduce versatile tests whose procedures are based on the simultaneous use of multiple WMST test statistics that are asymptotically normal under the null hypothesis of no difference between two groups. Simulations are performed to examine the power of the tests in moderate sample sizes when the data are uncensored to heavily censored with a ramp-up enrollment period. The survival scenarios chosen for simulation are intended to imitate those which are commonly encountered in oncology, especially in trials involving immunotherapies. Implementation of the procedures is discussed in two real data examples for illustration. Functions for performing versatile WMST tests are provided in the survWMST package in R.

Deep Learning for the Automatic Diagnosis and Analysis of Bone Metastasis on Bone Scintigrams

OBJECTIVE

To develop an approach for automatically analyzing bone metastases (BMs) on bone scintigrams based on deep learning technology.

METHODS

This research included a bone scan classification model, a regional segmentation model, an assessment model for tumor burden and a diagnostic report generation model. Two hundred eighty patients with BMs and 341 patients with non-BMs were involved. Eighty percent of cases were randomly extracted from two groups as training set. Remaining cases were as testing set. A deep residual convolutional neural network with different structures was used to determine whether metastatic bone lesions existed, regions of lesions were automatically segmented. Bone scan tumor burden index (BSTBI) was calculated; finally, diagnostic report could be automatically generated. The sensitivity, specificity and accuracy of classification model were compared with three physicians with different clinical experience. The Dice coefficient evaluated the effect of segmentation model and compared to the result of nnU-Net model. The correlation between BSTBI and blood alkaline phosphatase (ALP) level was analyzed to verify the efficiency of BSTBI. The performance of report generation model was evaluated by the accuracy of interpretation of report.

RESULTS

In testing set, the sensitivity, specificity and accuracy of classification model were 92.59%, 85.51% and 88.62%, respectively. The accuracy showed no statistical difference with moderately and experienced physicians and obviously outperformed the inexperienced. The Dice coefficient of BMs area was 0.7387 in segmentation stage. Based on the whole model frame, our segmentation model outperformed the nnU-Net. BSTBI value changed as the BMs changed. There was a positive correlation between BSTBI and ALP level. The accuracy of report generation model was 78.05%.

CONCLUSION

Deep learning based on automatic analysis frameworks for BMs can accurately identify BMs, preliminarily realize a fully automatic analysis process from raw data to report generation. BSTBI can be used as a quantitative evaluation indicator to assess the effect of therapy on BMs in different patients or in the same patient before and after treatment.

In Silico Model Estimates the Clinical Trial Outcome of Cancer Vaccines

Over 30 years after the first cancer vaccine clinical trial (CT), scientists still search the missing link between immunogenicity and clinical responses. A predictor able to estimate the outcome of cancer vaccine CTs would greatly benefit vaccine development. Published results of 94 CTs with 64 therapeutic vaccines were collected. We found that preselection of CT subjects based on a single matching HLA allele does not increase immune response rates (IRR) compared with non-preselected CTs (median 60% vs. 57%, p = 0.4490). A representative in silico model population (MP) comprising HLA-genotyped subjects was used to retrospectively calculate in silico IRRs of CTs based on the percentage of MP-subjects having epitope(s) predicted to bind ≥ 1–4 autologous HLA allele(s). We found that in vitro measured IRRs correlated with the frequency of predicted multiple autologous allele-binding epitopes (AUC 0.63–0.79). Subgroup analysis of multi-antigen targeting vaccine CTs revealed correlation between clinical response rates (CRRs) and predicted multi-epitope IRRs when HLA threshold was ≥ 3 (r = 0.7463, p = 0.0004) but not for single HLA allele-binding epitopes (r = 0.2865, p = 0.2491). Our results suggest that CRR depends on the induction of broad T-cell responses and both IRR and CRR can be predicted when epitopes binding to multiple autologous HLAs are considered.

Cancer vaccines: An unkept promise?

Two decades ago, cancer vaccines were hailed as a prominent breakthrough for the treatment of cancer. However, the vaccines failed to show any improvement in median survival time in various clinical trials, even though they stimulated the immune response and showed exceptional safety profiles. The resistance of cancer cells to the immune response was revealed as a significant hurdle. In this review, I discuss the different types of cancer vaccines and the strategies used to design them. I also highlight how cancer cells develop resistance to the immune response, and how therapies, such as monoclonal antibodies (mAbs) and small interfering (si)RNA/short hairpin (sh)RNA could be used to address some of the shortcomings of cancer vaccine treatments.

Lights and Shadows in Immuno-Oncology Drug Development

The rapidly evolving landscape of immuno-oncology (IO) is redefining the treatment of a number of cancer types. IO treatments are becoming increasingly complex, with different types of drugs emerging beyond checkpoint inhibitors. However, many of the new drugs either do not progress from phase I-II clinical trials or even fail in late-phase trials. We have identified at least five areas in the development of promising IO treatments that should be redefined for more efficient designs and accelerated approvals. Here we review those critical aspects of IO drug development that could be optimized for more successful outcome rates in all cancer types. It is important to focus our efforts on the mechanisms of action, types of response and adverse events of these novel agents. The use of appropriate clinical trial designs with robust biomarkers of response and surrogate endpoints will undoubtedly facilitate the development and subsequent approval of these drugs. Further research is also needed to establish biomarker-driven strategies to select which patients may benefit from immunotherapy and identify potential mechanisms of resistance.

Design for immuno-oncology clinical trials enrolling both responders and nonresponders

A typical challenge facing the design and analysis of immuno-oncology (IO) trials is the prevalence of nonproportional hazards (NPH) patterns manifested in Kaplan-Meier curves under time-to-event endpoints. The NPH patterns would violate the proportional hazards assumption, and yet conventional design and analysis strategies often ignore such a violation, resulting in underpowered or even falsely negative IO studies. In this article, we show, both empirically and analytically, that treating nonresponders in IO studies of inadequate size would give rise to a variety of NPH patterns; we then present a novel design and analysis strategy, P%-responder information embedded (PRIME), to properly incorporate the dichotomized response incurred from treating nonresponders. Empirical studies demonstrate that the proposed strategy can achieve desirable power, whereas the conventional alternative leads to a severe power loss. The PRIME strategy allows us to quantify the impact of treating nonresponders on study efficiency, thereby enabling a proper design of IO trials with an adequate power. More importantly, it pinpoints a solution to enhance the study efficiency and alleviates the NPH patterns by enrolling more prospective responders. An R package (Immunotherapy.Design) is developed for implementation.

Antibody-guided structure-based vaccines

The vaccine field is pursuing diverse approaches to translate the molecular insights from analyses of effective antibodies and their targeted epitopes into immunogens capable of eliciting protective immune responses. Here we review current antibody-guided strategies including conformation-based, epitope-based, and lineage-based vaccine approaches, which are yielding promising vaccine candidates now being evaluated in clinical trials. We summarize directions being employed by the field, including the use of sequencing technologies to monitor and track developing immune responses for understanding and improving antibody-based immunity. We review opportunities and challenges to transform powerful new discoveries into safe and effective vaccines, which are encapsulated by vaccine efforts against a variety of pathogens including HIV-1, influenza A virus, malaria parasites, respiratory syncytial virus, and SARS-CoV-2. Overall, this review summarizes the extensive progress that has been made to realize antibody-guided structure-based vaccines, the considerable challenges faced, and the opportunities afforded by recently developed molecular approaches to vaccine development.

Evaluation of the contribution of randomised cancer clinical trials evaluating agents without documented single-agent activity

BACKGROUND

With the development of targeted agents, the approach to combination cancer therapy has evolved to focus on identifying ways in which pathway inhibition by one agent may enhance the activity of other agents. In theory, this implies that under this new paradigm, agents are no longer required to show single-agent activity, as the pathway inhibited by the targeted agent may only have a therapeutic effect when given with other agents. This raises the question of the extent to which anticancer agents without single-agent activity can contribute to effective combination regimens.

PATIENTS AND METHODS

We reviewed outcomes of randomised phase 2 combination trials sponsored by the National Cancer Institute Cancer Therapy Evaluation Program that were activated in 2008 to 2017 and noted the single-agent activity of the experimental agents.

RESULTS

Fifty-three trials were identified, and 50 had available results: 7 (14%), 15 (30%) and 28 (56%) had experimental agents with single-agent activity classified as active, inactive and indeterminate, respectively. Thirteen per cent (95% CI=1.7% to 40.5%) of trials evaluating inactive agents and 11.6% (95% CI=3.9% to 25.1%) of trials evaluating agents without known single-agent activity (pooled inactive and indeterminate) were positive, compared with 42.9% (95% CI=9.9% to 81.6%) for agents with single-agent activity.

CONCLUSIONS

Incorporating agents without documented single-agent activity into treatment regimens is unlikely to produce meaningful improvements in activity unless there is compelling biological rationale. This finding has important implications for the prioritisation of anticancer agents for combination testing, and for the allocation of clinical trial resources.

Defining tumor resistance to PD-1 pathway blockade: recommendations from the first meeting of the SITC Immunotherapy Resistance Taskforce

As the field of cancer immunotherapy continues to advance at a fast pace, treatment approaches and drug development are evolving rapidly to maximize patient benefit. New agents are commonly evaluated for activity in patients who had previously received a programmed death receptor 1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitor as standard of care or in an investigational study. However, because of the kinetics and patterns of response to PD-1/PD-L1 blockade, and the lack of consistency in the clinical definitions of resistance to therapy, the design of clinical trials of new agents and interpretation of results remains an important challenge. To address this unmet need, the Society for Immunotherapy of Cancer convened a multistakeholder taskforce-consisting of experts in cancer immunotherapy from academia, industry, and government-to generate consensus clinical definitions for resistance to PD-(L)1 inhibitors in three distinct scenarios: primary resistance, secondary resistance, and progression after treatment discontinuation. The taskforce generated consensus on several key issues such as the timeframes that delineate each type of resistance, the necessity for confirmatory scans, and identified caveats for each specific resistance classification. The goal of this effort is to provide guidance for clinical trial design and to support analyses of emerging molecular and cellular data surrounding mechanisms of resistance.

Blood-derived dendritic cell vaccinations induce immune responses that correlate with clinical outcome in patients with chemo-naive castration-resistant prostate cancer

BACKGROUND

Clinical benefit of cellular immunotherapy has been shown in patients with castration-resistant prostate cancer (CRPC). We investigated the immunological response and clinical outcome of vaccination with blood-derived CD1c⁺ myeloid dendritic cells (mDCs; cDC2) and plasmacytoid DCs (pDCs).

METHODS

In this randomized phase IIa trial, 21 chemo-naive CRPC patients received maximally 9 vaccinations with mature mDCs, pDCs or a combination of mDCs plus pDCs. DCs were stimulated with protamine/mRNA and loaded with tumor-associated antigens NY-ESO-1, MAGE-C2 and MUC1. Primary endpoint was the immunological response after DC vaccination, which was monitored in peripheral blood and in T cell cultures of biopsies of post-treatment delayed-type hypersensitivity-skin tests. Main secondary endpoints were safety, feasibility, radiological PFS (rPFS) and overall survival. Radiological responses were assessed by MRIs and contrast-enhanced ⁶⁸Ga-prostate-specific membrane antigen PET/CT, according to RECIST 1.1, PCWG2 criteria and immune-related response criteria.

RESULTS

Both tetramer/dextramer-positive (dm⁺) and IFN-γ-producing (IFN-γ⁺) antigen specific T cells were detected more frequently in skin biopsies of patients with radiological non-progressive disease (5/13 patients; 38%) compared to patients with progressive disease (0/8 patients; 0%). In these patients with vaccination enhanced dm⁺ and IFN-γ⁺ antigen-specific T cells median rPFS was 18.8 months (n = 5) vs. 5.1 months (n = 16) in patients without IFN-γ-producing antigen-specific T cells (p = 0.02). The overall median rPFS was 9.5 months. All DC vaccines were well tolerated with grade 1-2 toxicity.

CONCLUSIONS

Immunotherapy with blood-derived DC subsets was feasible and safe and induced functional antigen-specific T cells. The presence of functional antigen-specific T cells correlated with an improved clinical outcome.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02692976, registered 26 February 2016, retrospectively registered.

Immunotherapy in HER2-positive breast cancer: state of the art and future perspectives

Breast cancer (BC) is a complex disease with primary or acquired incurability characteristics in a significant part of patients. Immunotherapeutical agents represent an emerging option for breast cancer treatment, including the human epidermal growth factor 2 positive (HER2+) subtype. The immune system holds the ability to spontaneously implement a defensive response against HER2+ BC cells through complex mechanisms which can be exploited to modulate this response for obtaining a clinical benefit. Initial immune system modulating strategies consisted mostly in vaccine therapies, which are still being investigated and improved. However, the entrance of trastuzumab into the scenery of HER2+ BC treatment was the real game changing event, which embodied a dominant immune-mediated mechanism. More recently, the advent of the immune checkpoint inhibitors has caused a new paradigm shift for immuno-oncology, with promising initial results also for HER2+ BC. Breast cancer has been traditionally considered poorly immunogenic, being characterized by relatively low tumor mutation burden (TMB). Nevertheless, recent evidence has revealed high tumor infiltrating lymphocytes (TILs) and programmed cell death-ligand 1 (PD-L1) expression in a considerable proportion of HER2+ BC patients. This may translate into a higher potential to elicit anti-cancer response and, therefore, wider possibilities for the use and implementation of immunotherapy in this subset of BC patients. We are herein presenting and critically discussing the most representative evidence concerning immunotherapy in HER2+ BC cancer, both singularly and in combination with therapeutic agents acting throughout HER2-block, immune checkpoint inhibition and anti-cancer vaccines. The reader will be also provided with hints concerning potential future projection of the most promising immutherapeutic agents and approaches for the disease of interest.

Immuno-Imaging to Predict Treatment Response in Infection, Inflammation and Oncology

Background: Molecular nuclear medicine plays a pivotal role for diagnosis in a preclinical phase, in genetically susceptible patients, for radio-guided surgery, for disease relapse evaluation, and for therapy decision-making and follow-up. This is possible thanks to the development of new radiopharmaceuticals to target specific biomarkers of infection, inflammation and tumour immunology. Methods: In this review, we describe the use of specific radiopharmaceuticals for infectious and inflammatory diseases with the aim of fast and accurate diagnosis and treatment follow-up. Furthermore, we focus on specific oncological indications with an emphasis on tumour immunology and visualizing the tumour environment. Results: Molecular nuclear medicine imaging techniques get a foothold in the diagnosis of a variety of infectious and inflammatory diseases, such as bacterial and fungal infections, rheumatoid arthritis, and large vessel vasculitis, but also for treatment response in cancer immunotherapy. Conclusion: Several specific radiopharmaceuticals can be used to improve diagnosis and staging, but also for therapy decision-making and follow-up in infectious, inflammatory and oncological diseases where immune cells are involved. The identification of these cell subpopulations by nuclear medicine techniques would provide personalized medicine for these patients, avoiding side effects and improving therapeutic approaches.

A Bayesian design for phase I cancer therapeutic vaccine trials

Phase I clinical trials are the first step in drug development to test a new drug or drug combination on humans. Typical designs of Phase I trials use toxicity as the primary endpoint and aim to find the maximum tolerable dosage. However, these designs are poorly applicable for the development of cancer therapeutic vaccines because the expected safety concerns for these vaccines are not as much as cytotoxic agents. The primary objectives of a cancer therapeutic vaccine phase I trial thus often include determining whether the vaccine shows biologic activity and the minimum dose necessary to achieve a full immune or even clinical response. In this paper, we propose a new Bayesian phase I trial design that allows simultaneous evaluation of safety and immunogenicity outcomes. We demonstrate the proposed clinical trial design by both a numeric study and a therapeutic human papillomavirus vaccine trial.

Designing cancer immunotherapy trials with random treatment time-lag effect

In some clinical settings such as the cancer immunotherapy trials, a treatment time-lag effect may be present and the lag duration possibly vary from subject to subject. An efficient study design and analysis procedure should not only take into account the time-lag effect but also consider the individual heterogeneity in the lag duration. In this paper, we present a Generalized Piecewise Weighted Logrank (GPW-Logrank) test, designed to account for the random time-lag effect while maximizing the study power with respect to the weights. Based on the proposed test, both analytic and numeric approaches are developed for the sample size and power calculation. Asymptotic properties are derived and finite sample efficiency is evaluated in simulations. Compared with the standard practice ignoring the delayed effect, the proposed design and analysis procedures are substantially more efficient when a random lag is expected; further, compared with the existing methods by Xu et al considering the fixed time-lag effect, the proposed approaches are significantly more robust when the lag model is misspecified. An R package (DelayedEffect.Design) is developed for implementation.

Immune Checkpoint Inhibitor Cancer Therapy: Spectrum of Imaging Findings

Immune checkpoint inhibitors are a new class of cancer therapeutics that have demonstrated striking successes in a rapid series of clinical trials. Consequently, these drugs have dramatically increased in clinical use since being first approved for advanced melanoma in 2011. Current indications in addition to melanoma are non-small cell lung cancer, head and neck squamous cell carcinoma, renal cell carcinoma, urothelial carcinoma, and classical Hodgkin lymphoma. A small subset of patients treated with immune checkpoint inhibitors undergoes an atypical treatment response pattern termed pseudoprogression: New or enlarging lesions appear after initiation of therapy, thereby mimicking tumor progression, followed by an eventual decrease in total tumor burden. Traditional response standards applied at the time of initial increase in tumor burden can falsely designate this as treatment failure and could lead to inappropriate termination of therapy. Currently, when new or enlarging lesions are observed with immune checkpoint inhibitors, only follow-up imaging can help distinguish patients with pseudoprogression from the large majority in whom this observation represents true treatment failure. Furthermore, the unique mechanism of immune checkpoint inhibitors can cause a distinct set of adverse events related to autoimmunity, which can be severe or life threatening. Given the central role of imaging in cancer care, radiologists must be knowledgeable about immune checkpoint inhibitors to correctly assess treatment response and expeditiously diagnose treatment-related complications. The authors review the molecular mechanisms and clinical applications of immune checkpoint inhibitors, the current strategy to distinguish pseudoprogression from progression, and the imaging appearances of common immune-related adverse events. ^©RSNA, 2017.

Serum immunoglobulin E response as a marker for unfavorable prognosis following cholesteryl pullulan-MAGE A4 vaccination

Since 2009, a cancer vaccine clinical trial was conducted with melanoma antigen gene-A4 as an immunogenic agent. The levels of IgG1, IgG2 and IgG3, which are known to be Type 1 T helper cell-associated antibodies, and the levels of IgG4 and IgE, which are known to be Type 2 T helper cell-associated antibodies, were measured and used as biomarkers for predicting therapeutic effect. The results of the present study indicated a strong positive correlation between IgG2 and IgG4, with a correlation coefficient of R=0.808 (P<0.0001). The survival time of patients in which IgE responses were induced was significantly shorter compared with the survival time of patients with no IgE induction. The results of the present study suggest that caution is required when antigen-specific IgE responses are induced during cancer vaccination therapy.

Immune-related tumour response assessment criteria: a comprehensive review

Growing emphasis on precision medicine in oncology has led to increasing use of targeted therapies that encompass a spectrum of drug classes including angiogenesis inhibitors, immune modulators, signal transduction inhibitors, DNA damage modulators, hormonal agents etc. Immune therapeutic drugs constitute a unique group among the novel therapeutic agents that are transforming cancer treatment, and their use is rising. The imaging manifestations in patients on immune therapies appear to be distinct from those typically seen with conventional cytotoxic therapies. Patients on immune therapies may demonstrate a delayed response, transient tumour enlargement followed by shrinkage, stable size, or initial appearance of new lesions followed by stability or response. These newer patterns of response to treatment have rendered conventional criteria such as World Health Organization and response evaluation criteria in solid tumours suboptimal in monitoring changes in tumour burden. As a consequence, newer imaging response criteria such as immune-related response evaluation criteria in solid tumours and immune-related response criteria are being implemented in many trials to effectively monitor patients on immune therapies. In this review, we discuss the traditional and new imaging response criteria for evaluation of solid tumours, review the outcomes of various articles which compared traditional criteria with the new immune-related criteria and discuss pseudo-progression and immune-related adverse events.

Melanoma antigen family A4 protein produced by transgenic silkworms induces antitumor immune responses

Recent clinical trials with the aim of developing tumor antigen (TA)-specific cancer vaccines against a number of malignancies have focused on the identification of TAs presented by tumor cells and recognized by T cells. In the present study, the TA melanoma antigen family A4 (MAGE-A4) protein was produced using a transgenic (TG) silkworm system. Using in vitro stimulation, it was subsequently determined whether MAGE-A4 protein induced MAGE-A4-specific T cells from peripheral blood mononuclear cells of healthy donors. TG silkworm lines expressing a MAGE-A4 gene under an upstream activating sequence (UAS) were mated with those expressing a yeast transcription activator protein (GAL4) at the middle silk glands (MSGs) and embryos that harbored both the GAL4 and UAS constructs were selected. Recombinant MAGE-A4 protein was extracted from the MSGs of TG silkworms and evaluated using SDS-PAGE and western blot analysis. It was observed that MAGE-A4 produced by the TG silkworm system successfully induced MAGE-A4-specific CD4⁺ T cell responses. Furthermore, MAGE-A4-specific CD4⁺ T cells recognized antigen-presenting cells when pulsed with a MAGE-A4⁺ tumor cell lysate. The present data suggests that recombinant tumor antigen production using the TG silkworm system may be a novel tool in the preparation of cancer vaccines.

Immuno-Oncology: The Third Paradigm in Early Drug Development

Clinical researchers in oncology face the difficulty of developing new drugs for treating cancer patients. This challenge nowadays extends towards new horizons since a high number of drugs are developed in each of the three paradigms: classical cytotoxics, new targeted agents, and emergent immunotherapeutic approaches. Over the last decade, there has been an unstoppable progress in this third paradigm, to the extent that in 2013 immunotherapy was granted the scientific breakthrough of the year. However, the novel mechanisms of action of these immunotherapeutic agents entail a whole new series of concepts, resulting in a number of unresolved questions to which clarification is crucial for their success: establishment of accurate preclinical models able to predict human toxicities, better selection of candidate populations, finding and validation of predictive biomarkers, definition of suitable endpoints, improvements in first-in-human study designs, proposal of more accurate radiological response criteria, management of novel immune-related toxicities and development of combinations based on a biological rationale. In this article, we review the major challenges to overcome in forthcoming years. The final role of immunotherapy in cancer will be determined by our capacity to shed some light on some of these key points.

Paradoxical response to osimertinib therapy in a patient with T790M-mutated lung adenocarcinoma

A 'paradoxical response' to cancer treatment is a term used to describe the emergence of unexpected new lesions and the progression of existing lesions, despite appropriate and effective therapy. 'Pseudo-progression' is a phenomenon in which lymphocytes activated by an immune checkpoint inhibitor accumulate in a tumor and expand its shadow, mimicking enlargement of the primary lesion or development of a new metastatic lesion. Patients receiving cancer chemotherapy may respond differently to treatment, by exhibiting a response, deterioration, or the simultaneous occurrence of both. These variations may be attributed to the heterogeneity of the cancer. However, differences in the temporary response to epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment are rarely observed. If such a phenomenon is observed, it should not affect the evaluation of the therapeutic effect or be considered as an indication for the discontinuation of treatment. We herein report a rare case of a transient increase in carcinomatous pleural fluid as a paradoxical response to osimertinib treatment in a patient with T790M-mutated lung adenocarcinoma. The primary lesion and pulmonary metastases responded well to therapy. Although this paradoxical response is very rare, of non-malignant nature, and does not usually require treatment modification of, physicians must acknowledge that it is not a clinically discouraging characteristic when using EGFR-TKI to treat T790M-mutated lung adenocarcinoma.

Optimizing tumor immune response through combination of radiation and immunotherapy

Radiation therapy and immunotherapy are two highly evolving modalities for the treatment of solid tumors. Immunotherapeutic drugs can either stimulate the immune system via immunogenic pathways or target co-inhibitory checkpoints. An augmented tumor cell recognition by host immune cells can be achieved post-irradiation, as irradiated tissues can release chemical signals which are sensed by the immune system resulting in its activation. Different strategies combining both treatment modalities were tested in order to achieve a better therapeutic response and longer tumor control. Both regimens act synergistically to one another with complimentary mechanisms. In this review, we explore the scientific basis behind such a combination, starting initially with a brief historical overview behind utilizing radiation and immunotherapies for solid tumors, followed by the different types of these two modalities, and the biological concept behind their synergistic effect. We also shed light on the common side effects and toxicities associated with radiation and immunotherapy. Finally, we discuss previous clinical trials tackling this multimodality combination and highlight future ongoing research.

Immune Checkpoint Inhibitors in Lung Cancer: Imaging Considerations

OBJECTIVE

The purpose of this article is to review the mechanisms of action of immune checkpoint inhibitors in the treatment of non-small cell lung cancer (NSCLC), highlight imaging manifestations of common adverse events, and discuss new criteria for using imaging to assess unique treatment response patterns.

CONCLUSION

Immune checkpoint inhibitor therapy is a breakthrough in cancer treatment that has shown unprecedented success when used for a variety of malignancies. In recent phase 3 clinical trials for NSCLC, monoclonal antibodies that target the programmed death-1 (PD-1) receptor and its ligand PD-L1 (i.e., the PD-1/PD-L1 axis) were associated with better overall survival in head-to-head comparisons with conventional cytotoxic chemotherapy. On the strength of the results of these trials, the PD-1 inhibitors nivolumab and pembrolizumab and the PD-L1 inhibitor atezolizumab recently received regulatory approval by the U.S. Food and Drug Administration for the treatment of advanced NSCLC. Because of their unique mechanisms of action, these agents differ from conventional cytotoxic chemotherapy in both patterns of treatment response and treatment-related adverse events. Given the rapidly expanding clinical use of immune checkpoint inhibitors and the central role of radiology in the care of patients with lung cancer, it is important for radiologists to be familiar with these agents and their unique imaging findings.

iRECIST: guidelines for response criteria for use in trials testing immunotherapeutics

Tumours respond differently to immunotherapies compared with chemotherapeutic drugs, raising questions about the assessment of changes in tumour burden-a mainstay of evaluation of cancer therapeutics that provides key information about objective response and disease progression. A consensus guideline-iRECIST-was developed by the RECIST working group for the use of modified Response Evaluation Criteria in Solid Tumours (RECIST version 1.1) in cancer immunotherapy trials, to ensure consistent design and data collection, facilitate the ongoing collection of trial data, and ultimate validation of the guideline. This guideline describes a standard approach to solid tumour measurements and definitions for objective change in tumour size for use in trials in which an immunotherapy is used. Additionally, it defines the minimum datapoints required from future trials and those currently in development to facilitate the compilation of a data warehouse to use to later validate iRECIST. An unprecedented number of trials have been done, initiated, or are planned to test new immune modulators for cancer therapy using a variety of modified response criteria. This guideline will allow consistent conduct, interpretation, and analysis of trials of immunotherapies.

Recurrent pleural effusions and cardiac tamponade as possible manifestations of pseudoprogression associated with nivolumab therapy- a report of two cases

Background

Checkpoint inhibitors are a class of agents that employ host’s adaptive immune defenses in fighting cancer. With many new indications and several ongoing clinical trials in a variety of malignancies, the usage of these agents is set to increase significantly. One of the key challenges patients and physicians face while using these drugs is with the appropriate assessment of response to therapy.

Case presentation

We are reporting two patients with lung cancer who were treated with nivolumab and experienced rapidly accumulating recurrent pleural effusions requiring multiple thoracenteses (6 and 4 times each for patient 1 and 2 respectively) with in the first few weeks of initiation of therapy and also developed pericardial effusion with cardiac tamponade requiring pericardiocentesis. Both patients had prior history of malignant spread to pleural and pericardial space in their disease course. Therapy was continued in the first patient with spontaneous resolution of effusions after 8 weeks and the disease showed near complete response to treatment on imaging at 16 weeks. Second patient declined to continue further treatment with nivolumab after 3 cycles due to recurrent effusions and cardiac tamponade, although there was some evidence of clinical response at discontinuation.

Conclusions

Patients with history of malignant involvement of visceral spaces should be monitored closely for rapidly accumulating effusions and particularly for cardiac tamponade, after initiation of therapy with nivolumab. This presentation could represent pseudoprogression, and continuation of therapy with close monitoring is prudent as long as effusions are manageable and there is no definitive evidence of progression elsewhere.

Designing therapeutic cancer vaccine trials with delayed treatment effect

Arming the immune system against cancer has emerged as a powerful tool in oncology during recent years. Instead of poisoning a tumor or destroying it with radiation, therapeutic cancer vaccine, a type of cancer immunotherapy, unleashes the immune system to combat cancer. This indirect mechanism-of-action of vaccines poses the possibility of a delayed onset of clinical effect, which results in a delayed separation of survival curves between the experimental and control groups in therapeutic cancer vaccine trials with time-to-event endpoints. This violates the proportional hazard assumption. As a result, the conventional study design based on the regular log-rank test ignoring the delayed effect would lead to a loss of power. In this paper, we propose two innovative approaches for sample size and power calculation using the piecewise weighted log-rank test to properly and efficiently incorporate the delayed effect into the study design. Both theoretical derivations and empirical studies demonstrate that the proposed methods, accounting for the delayed effect, can reduce sample size dramatically while achieving the target power relative to a standard practice. Copyright © 2016 John Wiley & Sons, Ltd.

RECIST 1.1 - Standardisation and disease-specific adaptations: Perspectives from the RECIST Working Group

Radiologic imaging of disease sites plays a pivotal role in the management of patients with cancer. Response Evaluation Criteria in Solid Tumours (RECIST), introduced in 2000, and modified in 2009, has become the de facto standard for assessment of response in solid tumours in patients on clinical trials. The RECIST Working Group considers the ability of the global oncology community to implement and adopt updates to RECIST in a timely manner to be critical. Updates to RECIST must be tested, validated and implemented in a standardised, methodical manner in response to therapeutic and imaging technology advances as well as experience gained by users. This was the case with the development of RECIST 1.1, where an expanded data warehouse was developed to test and validate modifications. Similar initiatives are ongoing, testing RECIST in the evaluation of response to non-cytotoxic agents, immunotherapies, as well as in specific diseases. The RECIST Working Group has previously outlined the level of evidence considered necessary to formally and fully validate new imaging markers as an appropriate end-point for clinical trials. Achieving the optimal level of evidence desired is a difficult feat for phase III trials; this involves a meta-analysis of multiple prospective, randomised multicentre clinical trials. The rationale for modifications should also be considered; the modifications may be proposed to improve surrogacy, to provide a more mechanistic imaging technique, or be designed to improve reproducibility of the imaging biomarker. Here, we present the commonly described modifications of RECIST, each of which is associated with different levels of evidence and validation.

Combining TGF-β1 knockdown and miR200c administration to optimize antitumor efficacy of B16F10/GPI-IL-21 vaccine

TGF-β1 secreted abundantly by tumors cells as well as present in the local microenvironment promotes neoplasm invasion and metastasis by triggering the epithelial to mesenchymal transition (EMT). MiR200c has been shown to suppress EMT and to regulate the cellular epithelial and interstitial state conversion, whereas the tumor vaccines are intended to specifically initiate or amplify a host response against evolving tumor cells. Our study aimed at optimizing the antitumor effects of the B16F10/glycosylphosphatidylinositol-interleukin 21 (B16F10/GPI-IL-21) tumor vaccine on melanoma bearing mice by combining the TGF-β1 knockdown and the administration of miR200c agomir. The mice were subcutaneously vaccinated with inactivated B16F10/GPI-IL-21 vaccine and challenged by B16F10 cells transfected with shTGF-β1 (B16F10/shTGF-β1 cells) or B16F10/shTGF-β1 cells with the administration of miR200c agomir. The later combination showed that, when compared with the mice in the control group that received no vaccination, vaccinated mice significantly increased NK and CTL activities, enhanced levels of IFN-γ, and reduced expression of TGF-β1, N-cadherin, Vimentin, Gli1/2, P-Smad2/3 and others involved in promoting expression of EMT-related molecules in tumor areas, and inhibited the melanoma metastasis in lungs and lymph nodes. Altogether, our findings demonstrate that this synergistic anti-cancer regimen effectively induces strong immune response and diminishes the melanoma progression.

Development of immuno-oncology drugs - from CTLA4 to PD1 to the next generations

Since the regulatory approval of ipilimumab in 2011, the field of cancer immunotherapy has been experiencing a renaissance. This success is based on progress in both preclinical and clinical science, including the development of new methods of investigation. Immuno-oncology has become a sub-specialty within oncology owing to its unique science and its potential for substantial and long-term clinical benefit. Immunotherapy agents do not directly attack the tumour but instead mobilize the immune system - this can be achieved through various approaches that utilize adaptive or innate immunity. Therefore, immuno-oncology drug development encompasses a broad range of agents, including antibodies, peptides, proteins, small molecules, adjuvants, cytokines, oncolytic viruses, bi-specific molecules and cellular therapies. This Perspective summarizes the recent history of cancer immunotherapy, including the factors that led to its success, provides an overview of novel drug-development considerations, summarizes three generations of immunotherapies that have been developed since 2011 and, thus, illustrates the breadth of opportunities these new generations of immunotherapies represent.

A Phase III Clinical Trial of the Epidermal Growth Factor Vaccine CIMAvax-EGF as Switch Maintenance Therapy in Advanced Non-Small Cell Lung Cancer Patients

PURPOSE

EGFR is a well-validated target for patients with non-small cell lung cancer (NSCLC). CIMAvax-EGF is a therapeutic cancer vaccine composed of human recombinant EGF conjugated to a carrier protein and Montanide ISA51 as adjuvant. The vaccine is intended to induce antibodies against self EGFs that block EGF-EGFR interaction.

EXPERIMENTAL DESIGN

To evaluate overall survival, safety, immunogenicity, and EGF concentration in serum after CIMAvax-EGF, a randomized phase III trial was done in patients with advanced NSCLC. Four to 6 weeks after first-line chemotherapy, 405 patients with stage IIIB/IV NSCLC were randomly assigned to a vaccine group, which received CIMAvax-EGF or a control group, treated with best supportive care.

RESULTS

Long-term vaccination was very safe. Most frequent adverse reactions were grade 1 or 2 injection-site pain, fever, vomiting, and headache. Vaccination induced anti-EGF antibodies and decreased serum EGF concentration. In the safety population, median survival time (MST) was 10.83 months in the vaccine arm versus 8.86 months in the control arm. These differences were not significant according the standard log rank (HR, 0.82; P = 0.100), but according a weighted log rank (P = 0.04) that was applied once the nonproportionality of the HR was verified. Survival benefit was significant (HR, 0.77; P = 0.036) in the per-protocol setting (patients receiving at least four vaccine doses): MST was 12.43 months for the vaccine arm versus 9.43 months for the control arm. MST was higher (14.66 months) for vaccinated patients with high EGF concentration at baseline.

CONCLUSIONS

Switch maintenance with CIMAvax-EGF was well tolerated and significantly increased MST of patients that completed induction vaccination. Baseline EGF concentration predicted survival benefit. Clin Cancer Res; 22(15); 3782-90. ©2016 AACR.

Imaging Biomarkers in Immunotherapy

Immune-based therapies have been in use for decades but recent work with immune checkpoint inhibitors has now changed the landscape of cancer treatment as a whole. While these advances are encouraging, clinicians still do not have a consistent biomarker they can rely on that can accurately select patients or monitor response. Molecular imaging technology provides a noninvasive mechanism to evaluate tumors and may be an ideal candidate for these purposes. This review provides an overview of the mechanism of action of varied immunotherapies and the current strategies for monitoring patients with imaging. We then describe some of the key researches in the preclinical and clinical literature on the current uses of molecular imaging of the immune system and cancer.

Emerging Therapeutic Options for HER2-Positive Breast Cancer

The natural history of HER2-positive breast cancer has progressively improved since the introduction of the first anti-HER2 directed therapy (trastuzumab). Trastuzumab has significantly increased survival of patients with HER2-positive metastatic breast cancer and, after the standardization of the use of this drug in the adjuvant setting in 2005, has also avoided many disease recurrences and, consequently, saved many lives. Later on, the introduction of lapatinib offered new choices for patients with advanced HER2-positive breast cancer, although the drug has failed to show a clear efficacy in the adjuvant setting. New promising drugs have been approved to broaden the horizon of HER2-positive breast cancer such as pertuzumab or T-DM1, but we need new options to further improve the management of these diseases. In this review, we cover new strategies that are currently under evaluation for the treatment of patients with HER2-positive breast cancer, including new tyrosine kinase inhibitors (neratinib, ONT-380), new antibody-drug conjugates targeting HER2 (MM-302), and new indications of already approved drugs (T-DM1), as well as the potential dual combinations of anti-HER2 therapy with phosphoinositide 3-kinase/mTOR or cell cycle inhibitors (palbociclib, abemaciclib). Last but not least, we briefly review a new paradigm of emerging approaches that involve the host immune response, HER2 breast cancer vaccines, and other immune strategies, including immune checkpoint inhibition.

Studying the lay of the land: views and experiences of professionals in the translational pluripotent stem cell field

AIM

The inherent uncertainty of first-in-human trials, combined with the technical complexity of pluripotent stem cells (PSCs), makes early phase PSC studies ethically challenging. Conducting parallel bioethics research based on experiences and views of professionals in the stem cell field is therefore important.

MATERIALS & METHODS

We conducted semistructured interviews with various stakeholders to get a lay of the land of ethical issues professionals find relevant to the translation of PSCs.

RESULTS

We identified four themes in the interviews: the uniqueness of PSCs, the suitability of the current research paradigm, the justification for early phase PSC studies and the involvement of patients and research participants.

CONCLUSION

We conclude that a debate should take place discussing the suitability of the current research paradigm for translational PSC studies.

Releasing the Brakes on Cancer Immunotherapy

This year's Lasker∼DeBakey Clinical Research Award goes to James Allison for discovering that antibody blockade of the T cell molecule CTLA-4 unleashes the body's immune response against malignant tumors. This has led to development of multiple "immune checkpoint therapies" that are prolonging and saving the lives of thousands of cancer patients.

Immunotherapy response assessment in neuro-oncology: a report of the RANO working group

Immunotherapy is a promising area of therapy in patients with neuro-oncological malignancies. However, early-phase studies show unique challenges associated with the assessment of radiological changes in response to immunotherapy reflecting delayed responses or therapy-induced inflammation. Clinical benefit, including long-term survival and tumour regression, can still occur after initial disease progression or after the appearance of new lesions. Refinement of the response assessment criteria for patients with neuro-oncological malignancies undergoing immunotherapy is therefore warranted. Herein, a multinational and multidisciplinary panel of neuro-oncology immunotherapy experts describe immunotherapy Response Assessment for Neuro-Oncology (iRANO) criteria based on guidance for the determination of tumour progression outlined by the immune-related response criteria and the RANO working group. Among patients who demonstrate imaging findings meeting RANO criteria for progressive disease within 6 months of initiating immunotherapy, including the development of new lesions, confirmation of radiographic progression on follow-up imaging is recommended provided that the patient is not significantly worse clinically. The proposed criteria also include guidelines for the use of corticosteroids. We review the role of advanced imaging techniques and the role of measurement of clinical benefit endpoints including neurological and immunological functions. The iRANO guidelines put forth in this Review will evolve successively to improve their usefulness as further experience from immunotherapy trials in neuro-oncology accumulate.

Validity of combination active specific immunotherapy for colorectal cancer: a meta-analysis of 2993 patients

BACKGROUND AIMS

The aim of this study was to investigate whether active specific immunotherapy (ASI) is able to demonstrate therapeutic efficacy against colorectal cancer.

METHODS

We conducted a systematic review of published papers from MEDLINE, the Cochrane Central Register of Controlled Trials, EMBASE, the Wanfang Database, the China Science and Technology Periodical Database and China Journal Net. Published data were extracted independently by two authors who used predefined database templates. The effects of ASI were compared with those of surgery alone, and a pooled analysis was performed with the use of the data from random- or fixed-effect models.

RESULTS

Twelve trials matched our inclusion criteria (n = 2993, including 1842 control subjects). The overall analysis showed a significant survival benefit [1-, 2-, 3-, 4-, 5-, 6- and 7-year overall survival (OS), P < 0.05; 10-year OS, P < 0.001] in favor of ASI immunotherapy combined with surgery, but there was not an improvement in the 8- or 9-year OS (P > 0.05). The disease-free survival (DFS) rate was improved after the combination of ASI immunotherapy (2-, 3-, 5- and 10-year DFS, P < 0.05), but no significant improvement was noted for the 1-, 4-, 6-, 7-, 8- or 9-year DFS (P > 0.05). In addition, the disease-specific survival (DSS) was improved at some time points after the combination of ASI immunotherapy and surgery (2-, 3-, 4-, 5- and 6-year DSS, P < 0.05, but not the 1-, 7-, 8- or 9-year DSS, P > 0.05). An improved 2-, 3-, 4-, 5- and 6-year recurrence-free interval (RFI) (P < 0.05) was also observed in patients who received ASI therapy, but this was not observed for the 1-year RFI (P > 0.05). Furthermore, an analysis of the recurrence-free survival (RFS) showed that it was significantly increased in the ASI plus surgery group (1-, 2-, 3-, 4-, 5- and 6-year RFS, P < 0.001). The funnel plots showed that the analyses were relatively reliable and the publication bias was small.

CONCLUSIONS

The combination of ASI immunotherapy and surgery was superior in prolonging the overall survival time and enhancing the recurrence-free survival rate compared with surgery alone.

Critical issues in cancer vaccine trial design

As the clinical experience with cancer vaccines and cancer immunotherapy increases, there are important lessons that can be learned from the successes and failures of past trials. Many lessons affect the design and conduct of clinical trials themselves. Appropriate patient selection, clinical trial design, immunologic monitoring, and appropriate endpoints are all essential to the efficiency and success of bringing cancer vaccines from conception to clinical use.

Safety and preliminary evidence of biologic efficacy of a mammaglobin-a DNA vaccine in patients with stable metastatic breast cancer

PURPOSE

Mammaglobin-A (MAM-A) is overexpressed in 40% to 80% of primary breast cancers. We initiated a phase I clinical trial of a MAM-A DNA vaccine to evaluate its safety and biologic efficacy.

EXPERIMENTAL DESIGN

Patients with breast cancer with stable metastatic disease were eligible for enrollment. Safety was monitored with clinical and laboratory assessments. The CD8 T-cell response was measured by ELISPOT, flow cytometry, and cytotoxicity assays. Progression-free survival (PFS) was described using the Kaplan-Meier product limit estimator.

RESULTS

Fourteen subjects have been treated with the MAM-A DNA vaccine and no significant adverse events have been observed. Eight of 14 subjects were HLA-A2(+), and the CD8 T-cell response to vaccination was studied in detail. Flow cytometry demonstrated a significant increase in the frequency of MAM-A-specific CD8 T cells after vaccination (0.9% ± 0.5% vs. 3.8% ± 1.2%; P < 0.001), and ELISPOT analysis demonstrated an increase in the number of MAM-A-specific IFNγ-secreting T cells (41 ± 32 vs. 215 ± 67 spm; P < 0.001). Although this study was not powered to evaluate progression-free survival (PFS), preliminary evidence suggests that subjects treated with the MAM-A DNA vaccine had improved PFS compared with subjects who met all eligibility criteria, were enrolled in the trial, but were not vaccinated because of HLA phenotype.

CONCLUSION

The MAM-A DNA vaccine is safe, capable of eliciting MAM-A-specific CD8 T-cell responses, and preliminary evidence suggests improved PFS. Additional studies are required to define the potential of the MAM-A DNA vaccine for breast cancer prevention and/or therapy.