Current and Emerging Perspectives on Immunotherapy for Melanoma

Nidogen-2 (NID2) is a Key Factor in Collagen Causing Poor Response to Immunotherapy in Melanoma

Background

The incidence of cutaneous melanoma continues to rise rapidly and has an extremely poor prognosis. Immunotherapy strategies are the most effective approach for patients who have developed metastases, but not all cases have been successful due to the complex and variable mechanisms of melanoma response to immune checkpoint inhibition.

Methods

We synthesized collagen-coding gene expression data (second-generation and single-cell sequencing) from public Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Bioinformatics analysis was performed using R software and several database resources such as Metascape database, Gene Set Cancer Analysis (GSCA) database, and Cytoscape software, etc., to investigate the biological mechanisms that may be related with collagens. Immunofluorescence and immunohistochemical staining were used to validate the expression and localization of Nidogen-2 (NID2).

Results

Melanoma patients can be divided into two collagen clusters. Patients with high collagen levels (C1) had a shorter survival than those with low collagen levels (C2) and were less likely to benefit from immunotherapy. We demonstrated that NID2 is a potential key factor in the collagen phenotype, is involved in fibroblast activation in melanoma, and forms a barrier to limit the proximity of CD8+ T cells to tumor cells.

Conclusion

We clarified the adverse effects of collagen on melanoma patients and identified NID2 as a potential therapeutic target.

Immunotherapy with radiotherapy in urological malignancies

PURPOSE OF REVIEW

Radiotherapy has the potential to augment the host's immune response to cancer. Urological malignancies are highly immunogenic and the combination of radiotherapy and immunotherapy shows promise. In this review, we discuss the effects of radiotherapy on the cancer immune system and highlight the rationale for using the combined approach in prostate, urothelial and renal cancers. Current clinical studies are summarized emphasising the synergistic effects of the combination and the possibility of improved clinical outcomes.

RECENT FINDINGS

Local and abscopal effects have been observed in different urological cancers when using a combined approach. Large fraction size is associated with an increased immune response. Multiple radiotherapy/immunotherapy combinations are being studied in several clinical trials although no combination has yet been introduced in to standard practice.

SUMMARY

Although our knowledge of immunomodulation by radiotherapy has improved significantly in recent times, there remain several unanswered questions regarding how to best use the combination in clinical practice. Ongoing trials will provide further insight into complex mechanisms governing radiotherapy-immunotherapy interactions, with potential to improve clinical outcomes.

Endocrinopathies with use of cancer immunotherapies

BACKGROUND

Immunomodulatory therapies, including CTLA-4 and PD-1 inhibitors, provide a directed attack against cancer cells by preventing T cell deactivation. However, these drugs also prevent the downregulation of auto-reactive T cells, resulting in immune-related adverse events (IRAEs). Reports show a varied incidence of endocrine IRAEs, ranging from 0% to 63%.

OBJECTIVE

To describe the frequency and clinical characteristics of endocrine IRAEs in patients taking cancer immunomodulatory therapies.

DESIGN

Retrospective cohort study.

PATIENTS

A total of 388 patients aged ≥18 years who were prescribed ipilimumab, nivolumab and/or pembrolizumab between 2009 and 2016 at our institution.

MEASUREMENTS

Biochemical criteria were used to define endocrine IRAEs, including thyroid, pituitary, pancreas and adrenal dysfunction, following use of immunomodulatory therapies.

RESULTS

Fifty endocrine IRAEs occurred in our cohort, corresponding to a rate of 12.9%. The most common endocrine IRAEs were thyroid dysfunction (11.1%), with a lower incidence of pituitary dysfunction (1.8% of patients).

CONCLUSIONS

Over 12% of patients receiving ipilimumab, nivolumab and/or pembrolizumab in our study sample developed an endocrine IRAE. Patients who undergo treatment with immunomodulatory therapies should be monitored for the development of endocrine IRAEs.

Triple negative breast cancer - prognostic role of immune-related factors: a systematic review

PURPOSE

Treatment of breast cancer has been increasingly successful in recent years with the advent of HER2-receptor targeted treatment and endocrine treatment. However, the triple negative subgroup of breast cancer (TNBC) (estrogen-, progesterone- and HER2-receptor negative) still lacks targeted treatment options. TNBC is a type of breast cancer that often affects younger women, and generally has a worse prognosis than other types of breast cancer. Recently, the complex role of the immune system in cancer growth, elimination and metastasis has been the object of increased attention. There is hope that a more detailed understanding of the intricate roles of the constituents of the immune system, will hold potential both as prognostic or predictive markers of cancer progression, but also as treatment targets for a wide range of tumors, including TNBC. The aim of this review is to provide an overview of the cellular immune microenvironment in TNBC, and to highlight areas in which TNBC may differ from other types of breast cancer.

MATERIAL AND METHODS

A search of PubMed was made using the terms 'triple negative breast cancer' and 'tumor infiltrating lymphocytes', 'CD8', 'CD4', 'B cells', 'natural killer cells', 'macrophages', myeloid derived suppressor cells', 'dendritic cells', 'immune check point inhibitor', 'CTLA-4' and 'PD-L1'.

RESULTS

We find that whilst factors such as TILs and certain subgroups of TILs (e.g., CD8 + and regulator T-cells) have been extensively researched, none of these markers are currently applicable to routine clinical practice. Also, TNBC differs from other types of breast cancer with regards to cellular composition of the immune infiltrate and PD-L1 expression, and the prognostic significance of these.

CONCLUSIONS

Immune-related factors have the potential as both prognostic and predictive biomarkers for new treatments targeting the immune system in breast cancer. However, multivariate analyses, taking other well-known factors into account, are required to determine the true value of these biomarkers. Also, differences between TNBC and other types of breast cancer may have implications for treatment and use of immune-related factors as biomarkers.

Checkpoint inhibitors and gastrointestinal immune-related adverse events

PURPOSE OF REVIEW

Recent development of checkpoint inhibitors is a challenge for oncologists. Indeed, it leads to specific immune adverse events, close to autoimmune disorders, which require a specific management. Colitis is one of the most frequent immune adverse events, in particular with anticytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) therapy.

RECENT FINDINGS

Severe colitis is frequent with immune checkpoint inhibitors and leads in a few cases to bowel perforation and death. This review focuses on specific pathogenic pathway and recent findings on risk factors and managements of colitis.

SUMMARY

Anti-CTLA-4 antibodies are the most involved immune checkpoint inhibitors in colitis, and the combinations with anti-programmed death ligand 1 dramatically increase the rate of colitis. The early use of budesonide, and in some cases corticosteroids and/or infliximab should be recommended, as colitis is responsive to infliximab in almost all cases. Immune-related colitis shares some characteristics with inflammatory bowel disease but with little specificity. In particular, it has been recently showed that gut microbiota could interact with anti-CTLA-4 treatment to modulate efficacy but also to induce colitis. This opens the way for preventive or curative treatments capable of inducing modulation of the microbiota or fecal transplantation.

Targeting the PD-1 pathway in pediatric solid tumors and brain tumors

While remarkable advances have been made in the treatment of pediatric leukemia over the past decades, new therapies are needed for children with advanced solid tumors and high-grade brain tumors who fail standard chemotherapy regimens. Immunotherapy with immune checkpoint inhibitors acting through the programmed cell death-1 (PD-1) pathway has shown efficacy in some chemotherapy-resistant adult cancers, generating interest that these agents may also be helpful to treat certain refractory pediatric malignancies. In this manuscript we review current strategies for targeting the PD-1 pathway, highlighting putative biomarkers and the rationale for investigation of these drugs to treat common pediatric tumors such as sarcoma, neuroblastoma, and high-grade glioma. We summarize the completed and ongoing clinical trial data available, and suggest potential applications for further study.

PD-1 inhibitor gastroenterocolitis: case series and appraisal of 'immunomodulatory gastroenterocolitis'

AIMS

PD-1 inhibitors facilitate immune response against certain tumour types, including melanoma. These drugs have led to prolonged survival but can also result in autoimmune-type side effects, including gastrointestinal inflammation. The histopathological effects of this medication class have not been well studied.

METHODS AND RESULTS

We identified 37 gastrointestinal tract biopsies from 20 patients taking a PD-1 or PD-L1 inhibitor and evaluated clinicopathological findings. Diarrhoea was the most common symptom, and endoscopic findings ranged from mild erythema to erosion/ulceration. Common histological findings included lamina propria expansion, villous blunting (if applicable), intra-epithelial neutrophils and increased crypt/gland apoptosis, although intra-epithelial lymphocytes were rarely prominent. A few cases showed crypt rupture with resultant histiocytic/granulomatous response. Most patients responded to drug cessation and/or steroids, but follow-up endoscopies were not performed.

CONCLUSIONS

PD-1/PD-L1 inhibitors can cause gastritis, enteritis and colitis, similar to other immunomodulatory antibodies (such as CTLA-4 inhibitors and PI3Kδ inhibitors), but the histological findings vary somewhat among drug classes. Clinical history, lack of prominent intra-epithelial lymphocytes and crypt rupture may help to distinguish PD-1 inhibitor gastroenterocolitis from mimics, which include other medication effect, inflammatory bowel disease, graft-versus-host disease, cytomegalovirus infection and autoimmune enteropathy.

Pharmacological interventions for melanoma: Comparative analysis using bayesian meta-analysis

We conducted a network meta-analysis in order to compare different strategies for managing melanoma patients. Electronic databases were searched for eligible randomized trials that compared different strategies in efficacy and tolerability. Five interventions were associated with a significant improvement in PFS over chemotherapy (all HR < 1): Ipilimumab, Tremelimumab, Nivolumab, Pembrolizumab 2 mg/kg and Ipilimumab + Nivolumab. Three interventions exhibited significantly improved OS results over chemotherapy (all HR < 1): Ipilimumab, Nivolumab and Ipilimumab + Chemotherapy. Four interventions were superior to chemotherapy in CR and PR (all OR > 1): Nivolumab, Pembrolizumab 10 mg/kg, Pembrolizumab 2 mg/kg and Ipilimumab + Nivolumab. However, the other seven interventions were associated with an increased risk of pruritus compared to chemotherapy (all OR > 1). Ipilimumab, Tremelimumab, Ipilimumab + Nivolumab and Ipilimumab + Chemotherapy might result in a higher risk of diarrhea compared to chemotherapy (all OR > 1). Immune checkpoint therapy or combined interventions might be more effective than chemotherapy for managing melanoma patients. However, chemotherapy appears to be more tolerable than these combined strategies with respect to adverse events.

Towards tumor immunodiagnostics

Immunodiagnostic markers applicable on tissue or cytologic material may be prognostic or predictive of response to immunomodulatory drugs and may also be classified according to whether they are cell-specific or tumor-tissue-specific. Cell-specific markers are evaluated under the microscope as (I) morphological, corresponding to the assessment of tumor infiltrating immune cells on routine hematoxylin & eosin (H&E) sections; and (II) immunophenotypic, including the immunohistochemical (IHC) assessment of markers characteristic for tumor infiltrating immune cells. Tumor-tissue-specific markers are assessed in tissue extracts that may be enriched in neoplastic cells but almost inevitably also contain stromal and immune cells infiltrating the tumor. Such markers include (I) immune-response-related gene expression profiles, and (II) tumor genotype characteristics, as recently assessed with large-scale genotyping methods, usually next generation sequencing (NGS) applications. Herein, we discuss the biological nature of immunodiagnostic markers, their potential clinical relevance and the shortcomings that have, as yet, prevented their clinical application.

Toll-like receptor agonist therapy can profoundly augment the antitumor activity of adoptively transferred CD8(+) T cells without host preconditioning

Background

Lymphodepletion enhances adoptive T cell transfer (ACT) therapy by activating the innate immune system via microbes released from the radiation-injured gut. Microbial components, such as LPS, are key mediators of total body irradiation (TBI) enhancement, but our ability to strategically use these toll-like receptor (TLR) agonists to bolster the potency of T cell-based therapies for cancer remains elusive. Herein, we used TLR4 agonist LPS as a tool to address how and when to use TLR agonists to effectively improve cancer immunotherapy.

Methods

To determine the mechanisms of how innate immune activation via lymphodepletion potentiated antitumor T cell immunity, we utilized the pmel-1 melanoma mouse model. B16F10-bearing mice were preconditioned with 5Gy TBI and given a tripartite ACT therapy (consisting of transferred pmel-1 CD8⁺ T cells, vaccination with fowlpox encoding gp100, and IL-2) along with TLR4 agonist LPS. The timing of LPS administration and the requirement of individual components of the tripartite therapy were evaluated based on tumor growth and the phenotype of recovered splenocytes by flow cytometry. We also evaluated the role of non-toxic and clinically used TLR4 and TLR9 agonists—monophosphoryl lipid A (MPL) and CpG Oligodeoxynucleotide (CpG ODN), respectively— for ACT therapy.

Results

Here we report that while exogenous administration of LPS was able to enhance adoptively transferred CD8⁺ T cells’ tumor destruction, LPS treatment alone did not replace individual components of the tripartite ACT regimen, or obviate TBI. Moreover, we found that sequentially administering LPS during or one day prior to ACT therapy compromised tumor regression. In contrast, administering LPS after ACT potentiated the antitumor effectiveness of the regimen, thereby supporting the expansion of transferred tumor-specific CD8⁺ T cells over host CD4⁺ T cells. We also found that non-toxic TLR agonists MPL and CpG potentiated the antitumor activity of infused CD8⁺ T cells. Finally, TBI was no longer needed to regress tumors in mice who were depleted of host CD4⁺ T cells, given a tripartite ACT regimen and then treated with low dose LPS.

Conclusions

Collectively, our results identify how and when to administer TLR agonists to augment T cell-based immunotherapy in the absence or presence of host preconditioning for treatment of advanced malignancies. Our findings have clinical implications for the design of next generation immune-based therapies for patients with cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s40425-016-0110-8) contains supplementary material, which is available to authorized users.