Immune Monitoring of Clinical Trials with Biotherapies

The therapeutic effect of wine-processed Corni Fructus on chronic renal failure in rats through the interference with the LPS/IL-1-mediated inhibition of RXR function

ETHNOPHARMACOLOGICAL RELEVANCE

Corni Fructus, derived from the fruit of Cornus officinalis Sieb. et Zucc, is a widely utilized traditional Chinese medicine (TCM) with established efficacy in the treatment of diverse chronic kidney diseases. Crude Corni Fructus (CCF) and wine-processed Corni Fructus (WCF) are the main processed forms of Corni Fructus. Generally, TCM is often used after processing (paozhi). Despite the extensive use of processed TCM, the underlying mechanisms of processing for most TCMs have been unclear so far.

AIM OF THE STUDY

In this study, an integrated strategy combined renal metabolomics with proteomics was established and investigated the potential processing mechanisms of CCF or WCF on chronic renal failure (CRF) models.

MATERIALS AND METHODS

Firstly, the differences in biochemical parameters and pathological histology were compared to evaluate the effects of CCF and WCF on CRF model rats. Then, the tissue differential metabolites and proteins between CCF and WCF on CRF model rats were screened based on metabolomics and proteomics technology. Concurrently, a combined approach of metabolomics and proteomics was employed to investigate the underlying mechanisms associated with these marker metabolic products and proteins.

RESULTS

Compared to the MG group, there were 27 distinct metabolites and 143 different proteins observed in the CCF-treatment group, while the WCF-treatment group exhibited 24 distinct metabolites and 379 different proteins. Further, the integration interactions analysis of the protein and lipid metabolite revealed that both WCF and CCF improved tryptophan degradation and LPS/IL-1-mediated inhibition of RXR function. WCF inhibited RXR function more than CCF via the modulation of LPS/IL-1 in the CRF model. Experimental results were validated by qRT-PCR and western blotting. Notably, the gene expression amount and protein levels of FMO3 and CYP2E1 among 8 genes influenced by WCF were higher compared to CCF.

CONCLUSION

The results of this study provide a theoretical basis for further study of Corni Fructus with different processing techniques in CRF. The findings also offer guidance for investigating the mechanism of action of herbal medicines in diseases employing diverse processing techniques.

Unlabeled image analysis-based cell viability assay with intracellular movement monitoring

The need for technologies to monitor cell health is increasing with advancements in the field of cell therapy and regenerative medicine. In this study, we demonstrated unlabeled optical metabolic imaging of cultured living cells. This imaging technique is based on motion vector analysis with a block-matching algorithm to compare sequential time-lapse images. Motion vector analysis evaluates the movement of intracellular granules observed with a phase-contrast microscope. We demonstrated that the motion speed of intracellular movement reflects adenosine triphosphate (ATP)-dependent intracellular trafficking in cells. We also confirmed that intracellular motion speed is correlated with the ATP concentrations of the cells. This assay can measure cellular viability at a single-cell level without requiring any reagents.

Statistical Considerations in Clinical Trial Design of Immunotherapeutic Cancer Agents

The classical model for identification and clinical development of anticancer agents was based on small molecules, which were often quite toxic. Early studies in small groups of patients would seek to identify a maximum tolerated dose and major dose-limiting toxicities. Tumor response (shrinkage) would be assessed after a minimum number of doses in phase II testing. The decision to take the drug into the randomized phase III clinical setting was usually based on the proportion and duration of objective tumor responses, along with overall survival compared with historical controls. Immune-oncologics that are designed to fight cancer by direct CD8(+) T-cell priming and activation or by blocking a negative regulatory molecule have a number of sharp distinctions from cytotoxic drugs. These include cytoreductive effects that may be very different in timing of onset from traditional chemotherapy and the potential for inducing long-term durable remissions even in heavily pretreated patients with metastatic disease. In this paper we review the different classes of immune-oncologic drugs in clinical development with particular attention to the biostatistical challenges associated with evaluating efficacy in clinical trials. Confronting these issues upfront is particularly important given the rapidly expanding number of clinical trials with both monotherapy and combination trials in immunooncology.

Prospect and progress of personalized peptide vaccinations for advanced cancers

INTRODUCTION

The field of cancer immunotherapy has made dramatic progress in the past 20 years, in part due to the identification of numerous tumor-associated antigens (TAAs). We have developed a novel immunotherapeutic approach called the personalized peptide vaccine (PPV), in which a maximum of four human leukocyte antigen (HLA)-matched vaccine peptides are selected based on the pre-existing host immunity before vaccination.

AREAS COVERED

This review describes recent progress in the use of PPV for various types of advanced cancer.

EXPERT OPINION

Although various approaches for therapeutic cancer immunotherapies, including peptide-based vaccines, have been developed and clinically examined, the diverse and heterogeneous characteristics of tumor cells and host immunity seem to limit their therapeutic efficacy. Selection of suitable peptide vaccines for individual patients based on the pre-existing host immunity before vaccination could resolve this limitation and could be a rational approach for developing effective cancer vaccines.

Immune responses to cancer: are they potential biomarkers of prognosis?

Recent technical improvements in evaluations of immune cells in situ and immune monitoring of patients with cancer have provided a wealth of new data confirming that immune cells play a key role in human cancer progression. This, in turn, has revived the expectation that immune endpoints might serve as reliable biomarkers of outcome or response to therapy in cancer. The recent successes in linking the T-cell signature in human colorectal carcinoma (CRC) with prognosis have provided a strong motive for searching for additional immune biomarkers that could serve as intermediate endpoints of response to therapy and outcome in human cancers. A number of potentially promising immune biomarkers have emerged, but most remain to be validated. Among them, the B-cell signature, as exemplified by expression of the immunoglobulin G kappa chain (IGKC) in tumor-infiltrating lymphocytes (TIL), has been validated as a biomarker of response to adjuvant therapy and better survival in patients with breast carcinoma and several other types of human solid tumors. Additional immune endpoints are being currently tested as potentially promising biomarkers in cancer. In view of currently growing use of immune cancer therapies, the search for immune biomarkers of prognosis are critically important for identifying patients who would benefit the most from adjuvant immunotherapy.

Personalized peptide vaccination: a new approach for advanced cancer as therapeutic cancer vaccine

Since both tumor cells and host immune cell repertoires are diverse and heterogeneous, immune responses against tumor-associated antigens should differ substantially among individual cancer patients. Selection of suitable peptide vaccines for individual patients based on the preexisting host immunity before vaccination could induce potent anti-tumor responses that provide clinical benefit to cancer patients. We have developed a novel immunotherapeutic approach of personalized peptide vaccination (PPV) in which a maximum of four human leukocyte antigen (HLA) class IA-matched peptides are selected for vaccination among pooled peptides on the basis of both HLA class IA type and the preexisting host immunity before vaccination. In this review, we discuss our recent results of preclinical and clinical studies of PPV for various types of advanced cancer.

Personalized peptide vaccination: a novel immunotherapeutic approach for advanced cancer

Since both tumor cells and immune cell repertoires are diverse and heterogeneous, immune responses against tumor-associated antigens might be substantially different among individual patients. Personalized selection of right peptides for individuals could thus be an appropriate strategy for cancer vaccines. We have developed a novel immunotherapeutic approach, personalized peptide vaccination (PPV), in which HLA-matched peptides are selected and administered, based on the pre-existing host immunity before vaccination. Recent clinical trials of PPV have demonstrated a feasibility of this new therapeutic approach in various types of advanced cancers. For example, a randomized phase II trial for patients with castration resistant prostate cancer showed a possible clinical benefit in the PPV group. In the patients undergoing PPV, lymphocyte counts, increased IgG responses to the vaccine peptides, and inflammatory factors in pre-vaccination peripheral blood might be potential biomarkers for prognosis. Further randomized phase III trials would be recommended to prove clinical benefits of PPV.

Generation of immunogenic and tolerogenic clinical-grade dendritic cells

Immunotherapy with dendritic cells (DCs), which have been manipulated ex vivo to become immunogenic or tolerogenic, has been tested in clinical trials for disease therapy. DCs are sentinels of the immune system, which after exposure to antigenic or inflammatory signals and crosstalk with effector CD4(+) T cells express high levels of costimulatory molecules and cytokines. Upregulation of either costimulatory molecules or cytokines promotes immunologic DCs, whereas their downregulation generates tolerogenic DCs (TDCs), which induce T regulatory cells (Tregs) and a state of tolerance. Immunogenic DCs are used for the therapy of infectious diseases such as HIV-1 and cancer, whereas tolerogenic DCs are used in treating various autoimmune diseases and in transplantation. DC vaccination is still at an early stage, and improvements are mainly needed in quality control of monitoring assays to generate clinical-grade DC products and to assess the effect of DC vaccination in future clinical trials. Here, we review the recent work in DC generation and monitoring approaches for DC-based trials with immunogenic or tolerogenic DCs.

Phase I trial of a personalized peptide vaccine for patients positive for human leukocyte antigen--A24 with recurrent or progressive glioblastoma multiforme

PURPOSE

Personalized selection of suitable peptides for patients could offer a novel approach to developing cancer vaccines that boost anticancer immunity. We present the results of a phase I trial of 14 kinds of vaccine candidates (ITK-1) in patients with recurrent or progressive glioblastoma multiforme (GBM).

PATIENTS AND METHODS

From January 2006 to January 2008, 12 patients from eight Japanese hospitals who were positive for human leukocyte antigen-A24, including 10 patients refractory to temozolomide (TMZ), were enrolled. The dose escalation trial included three dose groups (1, 3, and 5 mg) to determine the safety and tolerability of ITK-1 peptides. Immunologic response was monitored by measuring levels of cytotoxic T-lymphocyte precursors and peptide-specific immunoglobulin G. In another ITK-1 phase I trial for advanced prostate cancer, the vaccination schedule was skipped or discontinued in all three patients receiving the highest dose (5 mg/peptide) because of injection site reactions. This trial was therefore ended without enrollment for the highest dose, and data were analyzed by intention to treat.

RESULTS

No serious adverse drug reactions were encountered, and treatment was well tolerated. The vaccine induced dose-dependent immune boosting. The recommended dose of ITK-1 peptides is 3 mg/peptide.

CONCLUSION

Personalized vaccination with ITK-1 peptides could be recommended in further stages of clinical trials. The safety and increased frequency of immune boosting offers potential clinical benefits in cases of recurrent or progressive GBM, even in TMZ-refractory settings.

Overcoming the hurdles of randomised clinical trials of therapeutic cancer vaccines

Most of the recent randomised clinical trials of therapeutic cancer vaccines have failed to demonstrate a meaningful therapeutic benefit to patients over existing treatments. Furthermore, some clinical trials have demonstrated a detrimental effect on patients, resulting in poorer outcomes. These unexpected results have shed light on several important issues to be solved for further development of cancer vaccines. As has been discussed with respect to the use of granulocyte-macrophage colony-stimulating factor (GM-SCF) as an adjuvant, the failures of clinical trials may be explained, in part, by a vaccine-specific adverse event, i.e. the induction of an 'inconvenient immune response' that inhibits pre-existing host immunity. This hypothesis may be supported by the fact that randomised trials of personalised peptide vaccines that were selected in consideration of pre-existing host immunities in individual patients resulted in clear benefit to patients. The development of reliable biomarkers for the selection of appropriate patients and vaccine antigens would thus be pivotal to prevent such vaccine-specific adverse events. This article discusses possible ways to overcome the hurdles of randomised clinical trials of therapeutic cancer vaccines based on a review of recently conducted clinical trials.