Combined Nivolumab and Ipilimumab or Monotherapy in Untreated Melanoma

Cancer immunotherapy: the beginning of the end of cancer?

These are exciting times for cancer immunotherapy. After many years of disappointing results, the tide has finally changed and immunotherapy has become a clinically validated treatment for many cancers. Immunotherapeutic strategies include cancer vaccines, oncolytic viruses, adoptive transfer of ex vivo activated T and natural killer cells, and administration of antibodies or recombinant proteins that either costimulate cells or block the so-called immune checkpoint pathways. The recent success of several immunotherapeutic regimes, such as monoclonal antibody blocking of cytotoxic T lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD1), has boosted the development of this treatment modality, with the consequence that new therapeutic targets and schemes which combine various immunological agents are now being described at a breathtaking pace. In this review, we outline some of the main strategies in cancer immunotherapy (cancer vaccines, adoptive cellular immunotherapy, immune checkpoint blockade, and oncolytic viruses) and discuss the progress in the synergistic design of immune-targeting combination therapies.

Nivolumab in combination with ipilimumab for the treatment of melanoma

Melanoma patients develop resistance to most therapies, including chemo- and targeted-therapy drugs. Single-agent therapies are ineffective due to the heterogeneous nature of tumors comprising several subpopulations. Treatment of melanoma with immune-based therapies such as anti-cytotoxic T-lymphocyte activation-4 and anti-programmed death-1 antibodies has shown modest but long-lasting responses. Unfortunately, only subsets of melanoma patients respond to antibody-based therapies. Heterogeneity in lymphocyte infiltration and low frequency of anti-melanoma-reactive T-cells in tumor lesions are partly responsible for a lack of response to antibody-based therapies. Both antibodies have same biological function but they bind to different ligands at various phases of T-cell activity. Thus, combination therapy of antibodies has shown superior response rates than single-agent therapy. However, toxicity is a cause of concern in these therapies. Future identification of therapy-response biomarkers, mobilization of tumor-reactive T-cell infiltration using cancer vaccines, or non-specific targeted-therapy drugs will minimize toxicity levels and provide long-term remissions in melanoma patients.

Current clinical immunotherapeutic approaches for head and neck cancer

It was estimated that 59,340 new cases of head and neck cancer would be diagnosed in the US alone in 2015 and that 12,290 deaths would be attributed to the disease. Local and regional recurrences may be treated with chemotherapy and radiation; however, metastatic head and neck cancer is fatal and is treated with chemotherapy for palliation. Recent successful treatment of a variety of solid and hematological malignancies by immunotherapeutic approaches (i.e. harnessing the body's own immune system to combat disease) has added a fourth therapeutic option for the treatment of cancer. This commentary will review the status of immunotherapies in clinical development for the specific treatment of head and neck cancer.

Mass spectrometry-based antigen discovery for cancer immunotherapy

The antigenic landscape of tumors is distinct from healthy cells and has been the rationale behind a variety of vaccination trials. Typically the target tumor-associated antigens have been of self origin and have rarely induced effective anti-tumor responses. Recent data show that activation of the immune system by immune checkpoint blocking therapies leads to tumor rejection and that recognition of mutated antigens, known as 'neo-antigens' plays a key role. Discovery of neo-antigens relies mainly on prediction-based interrogation of the 'mutanome' using genomic information as input, followed by T-cell screening. Recent breakthroughs in mass spectrometry (MS) based immunopeptidomics have allowed the discovery of very large pools of naturally presented peptides, among them neo-epitopes. This review highlights the current progress related to neo-antigens discovery with emphasis on prediction algorithms and MS as well as the synergy of the two methodologies and how they can be exploited to develop effective personalized immunotherapy.

Taking a Toll on Self-Renewal: TLR-Mediated Innate Immune Signaling in Stem Cells

Innate immunity has evolved as the front-line cellular defense mechanism to acutely sense and decisively respond to microenvironmental alterations. The Toll-like receptor (TLR) family activates signaling pathways in response to stimuli and is well-characterized in both resident and infiltrating immune cells during neural inflammation, injury, and degeneration. Innate immune signaling has also been observed in neural cells during development and disease, including in the stem and progenitor cells that build the brain and are responsible for its homeostasis. Recently, the activation of developmental programs in malignant brain tumors has emerged as a driver for growth via cancer stem cells. In this review we discuss how innate immune signaling interfaces with stem cell maintenance in the normal and neoplastic brain.

Severe acute interstitial nephritis after combination immune-checkpoint inhibitor therapy for metastatic melanoma

Immune-checkpoint inhibitors are emerging as revolutionary drugs for certain malignancies. However, blocking the co-inhibitory signals may lead to immune-related adverse events, mainly in the spectrum of autoimmune diseases including colitis, endocrinopathies and nephritis. Here, we report a case of a 75-year-old man with metastatic malignant melanoma treated with a combination of nivolumab (anti-PD1-antibody) and ipilimumab (anti-CTLA-4 antibody) who developed systemic rash along with severe acute tubulointerstitial nephritis after two doses of combination therapy. Kidney biopsy and peripheral blood immune profile revealed highly proliferative and cytotoxic T cell features. Herein, we discuss the pathophysiology and management of immune checkpoint blockade-related adverse events.

Sequential treatment with immunotherapy and BRAF inhibitors in BRAF-mutant advanced melanoma

PURPOSE

Immunotherapy (IT) agents and BRAF inhibitors (BRAFi) are effective treatments for patients with advanced BRAF-mutant melanoma although the optimal sequence remains to be elucidated. The aim of this study was to compare the outcomes of two different cohorts of patients treated with BRAFi first, then IT or the reverse sequence.

PATIENTS AND METHODS

This is a retrospective study on two groups of patients: a cohort was treated first with BRAFi followed by immunotherapy (BRAFi-IT) and the other cohort with the reverse sequence (IT-BRAFi). Baseline characteristics and clinical outcomes were compared between the two cohorts.

RESULTS

A total of 25 patients were included in the study. Sixteen patients were given BRAFi-IT sequence and nine received IT-BRAFi sequence. No differences were observed in the characteristics of patients prior to each treatment between cohorts. Objective response rate (ORR) achieved by BRAFi were not different among groups. ORR achieved by IT was higher when administered after BRAFi (43.8 vs 0 %). Survival rates at 1-2 years were similar in both cohorts and median overall survival was not different for BRAFi-IT and IT-BRAFi (log rank test p = 0.97).

CONCLUSIONS

No differences were observed in OS between the two cohorts. These results support the indistinct use of IT or BRAFi as initial treatment in patients with metastatic BRAF-mutant melanoma, although higher rate of response to IT was observed when administered after BRAFi. Prospective randomized clinical trials are needed on this issue.

Harnessing the immune system for the treatment of melanoma: current status and future prospects

When malignant melanoma is diagnosed early, surgical resection is the intervention of choice and is often curative, but many patients present with unresectable disease at later stages. Due to its complex etiology paired with well-documented chemoresistance and high metastatic potential, patients with advanced melanoma had a poor prognosis, and the treatment of this disease remained unsatisfactory for many years. Recently, targeted therapy, immune checkpoint inhibition, or combinatory approaches have revolutionized the therapeutic options of melanoma allowing considerable improvement in disease control and survival. In this review we will summarize these novel therapeutic strategies with particular focus on combinatory immunotherapies and further discuss recent data derived from immunogenomic studies and potential options to improve the therapeutic efficacy of immune modulatory approaches.

Ipilimumab (Anti-Ctla-4 Mab) in the treatment of metastatic melanoma: Effectiveness and toxicity management

In the last years the onset of new therapies changed the management of malignant melanoma. Anti CTLA-4 antibody ipilimumab was the first drug to achieve a significant improvement in survival of advanced stage melanoma. This new therapeutic agent is characterized by a number of side effects that are totally different from those of traditional chemotherapy, mainly caused by the immune system activation. The purpose of this paper is to underline the central role of ipilimumab in the treatment of metastatic melanoma and to characterize related adverse events in terms of incidence, duration and severity of presentation. The early recognition of these side effects is crucial in order to ensure an appropriate management of the toxicities, thus reducing the long term clinical sequelae and the inappropriate treatment discontinuation.

Current Challenges in Cancer Treatment

PURPOSE

In this review, we highlight the current concepts and discuss some of the current challenges and future prospects in cancer therapy. We frequently use the example of lung cancer.

METHODS

We conducted a nonsystematic PubMed search, selecting the most comprehensive and relevant research articles, clinical trials, translational papers, and review articles on precision oncology and immuno-oncology. Papers were prioritized and selected based on their originality and potential clinical applicability.

FINDINGS

Two major revolutions have changed cancer treatment paradigms in the past few years: targeting actionable alterations in oncogene-driven cancers and immuno-oncology. Important challenges are still ongoing in both fields of cancer therapy. On the one hand, druggable genomic alterations are diverse and represent only small subsets of patients in certain tumor types, which limits testing their clinical impact in biomarker-driven clinical trials. Next-generation sequencing technologies are increasingly being implemented for molecular prescreening in clinical research, but issues regarding clinical interpretation of large genomic data make their wide clinical use difficult. Further, dealing with tumor heterogeneity and acquired resistance is probably the main limitation for the success of precision oncology. On the other hand, long-term survival benefits with immune checkpoint inhibitors (anti-programmed death cell protein-1/programmed death cell ligand-1[PD-1/L1] and anti-cytotoxic T lymphocyte antigen-4 monoclonal antibodies) are restricted to a minority of patients, and no predictive markers are yet robustly validated that could help us recognize these subsets and optimize treatment delivery and selection. To achieve long-term survival benefits, drug combinations targeting several molecular alterations or cancer hallmarks might be needed. This will probably be one of the most challenging but promising precision cancer treatment strategies in the future.

IMPLICATIONS

Targeting single molecular abnormalities or cancer pathways has achieved good clinical responses that have modestly affected survival in some cancers. However, this approach to cancer treatment is still reductionist, and many challenges need to be met to improve treatment outcomes with our patients.

Immune infiltrates in the breast cancer microenvironment: detection, characterization and clinical implication

Although unlike melanoma, breast cancer is not generally viewed as a highly immunogenic cancer, recent studies have described a rich tumor immune microenvironment in a subset of breast cancers. These immune infiltrates, comprised cells from the innate and adaptive immune response, can be detected and characterized in biopsy specimens and have prognostic value. Tumor-infiltrating lymphocytes (TILs) represent the majority of mononuclear immune infiltrates in the breast tumor microenvironment and can be easily identified in formalin-fixed paraffin-embedded tissues after standard hematoxylin and eosin staining. High levels of TILs are most common in HER2+ and basal-like subtypes where they are associated with good prognosis and with response to certain therapies such as the anti-HER2 antibody trastuzumab. International collaborative efforts are underway to standardize the assessment of TILs so as to facilitate their implementation as a breast cancer biomarker. Using immunohistochemistry to further characterize TILs, recent reports describe the presence of important lymphocyte populations including CD8+ cytotoxic, FOXP3+ regulatory, and CD4+ helper and follicular T cells which have overlapping associations with prognosis and response to therapies. Moreover, recently identified immune checkpoint markers (PD-1, PD-L1) are present in some breast cancers, implying some cases might be especially amenable to immune checkpoint inhibitor treatment strategies which are being evaluated in a number of active clinical trials.

PD-L1 expression in non-small cell lung cancer: Correlations with genetic alterations

Inhibition of the PD-1/PD-L1 pathway may induce anticancer immune responses in non-small cell lung cancer (NSCLC). Two PD-L1 immunohistochemistry (IHC) assays have been approved as companion diagnostic tests for therapeutic anti-PD-1 antibodies. However, many aspects of PD-L1 prevalence and association with genetically defined subtypes have not been addressed systematically. Here, we analyzed PD-L1 expression in 436 genetically annotated NSCLC specimens enriched for early stages using PD-L1 antibody 5H1. Expression of PD-L1 was detected in the tumor cells (TC) (34% of cases) and in associated immune cells (IC) (49%) across all stages of NSCLC, either alone or in combination. PD-L1 IHC-positive TC, but not IC showed significantly higher PD-L1 RNA expression levels. Expression in TC was associated with TP53, KRAS and STK11 mutational status in adenocarcinomas (AD) and with NFE2L2 mutations in squamous cell carcinomas (SQ). No correlations with histological subtype, clinical characteristics and overall survival were found. The presence of PD-L1-positive IC was significantly associated with patients' smoking status in AD. The findings are in agreement with the emerging concept that tumors with high mutational burden are more likely to benefit from immunotherapy, since TP53 and KRAS mutations are linked to smoking, increased numbers of somatic mutations and expression of neoantigens. Current clinical studies focus on stage IIIB and IV NSCLC; however, PD-L1 expression occurs in earlier stages and might be a predictive biomarker in clinical trials testing (neo-) adjuvant strategies.

Clinical activity and safety of Pembrolizumab in Ipilimumab pre-treated patients with uveal melanoma

BACKGROUND

Untreated metastatic uveal melanoma (UM) carries a grave prognosis. Unlike cutaneous melanoma (CM), there are no established treatments known to significantly improve outcomes for a meaningful proportion of patients. Inhibition of the PD1-PDL1 axis has shown promise in the management of CM and we here report a two center experience of UM patients receiving pembrolizumab.

METHODS

To assess the efficacy and safety of pembrolizumab, we retrospectively analyzed outcome data of 25 consecutive UM patients participating in the MK3475 expanded access program (EAP) who received pembrolizumab at 2 mg/kg 3 weekly. Tumor assessment was evaluated using RECIST 1.1 and immune-related Response Criteria (irRC) by CT scanning. Toxicity was recorded utilizing Common Terminology Criteria for Adverse Events ("CTCAE") v4.03.

RESULTS

Twenty-five patients were identified receiving a median of six cycles of treatment. Two patients achieved a partial response and six patients stable disease. After a median follow-up of 225 d median progression free survival (PFS) was 91 d and overall survival (OS) was not reached. There was a significant trend for improved outcomes in patients with extrahepatic disease progression as opposed to liver only progression at the outset. Five patients experienced grade 3 or 4 adverse events (AEs); there were no treatment related deaths.

CONCLUSIONS

Pembrolizumab 2mg/kg q3w is a safe option in UM patients. Disease control rates, particularly in the subgroup of patients without progressive liver disease at the outset are promising; these results merit further investigation in clinical trials possibly incorporating liver targeted treatment modalities.

Immunotherapy of cancer: from monoclonal to oligoclonal cocktails of anti-cancer antibodies: IUPHAR Review 18

Antibody-based therapy of cancer employs monoclonal antibodies (mAbs) specific to soluble ligands, membrane antigens of T-lymphocytes or proteins located at the surface of cancer cells. The latter mAbs are often combined with cytotoxic regimens, because they block survival of residual fractions of tumours that evade therapy-induced cell death. Antibodies, along with kinase inhibitors, have become in the last decade the mainstay of oncological pharmacology. However, partial and transient responses, as well as emergence of tumour resistance, currently limit clinical application of mAbs. To overcome these hurdles, oligoclonal antibody mixtures are being tested in animal models and in clinical trials. The first homo-combination of two mAbs, each engaging a distinct site of HER2, an oncogenic receptor tyrosine kinase (RTK), has been approved for treatment of breast cancer. Likewise, a hetero-combination of antibodies to two distinct T-cell antigens, PD1 and CTLA4, has been approved for treatment of melanoma. In a similar vein, additive or synergistic anti-tumour effects observed in animal models have prompted clinical testing of hetero-combinations of antibodies simultaneously engaging distinct RTKs. We discuss the promise of antibody cocktails reminiscent of currently used mixtures of chemotherapeutics and highlight mechanisms potentially underlying their enhanced clinical efficacy.

Mechanism-driven biomarkers to guide immune checkpoint blockade in cancer therapy

With recent approvals for multiple therapeutic antibodies that block cytotoxic T lymphocyte associated antigen 4 (CTLA4) and programmed cell death protein 1 (PD1) in melanoma, non-small-cell lung cancer and kidney cancer, and additional immune checkpoints being targeted clinically, many questions still remain regarding the optimal use of drugs that block these checkpoint pathways. Defining biomarkers that predict therapeutic effects and adverse events is a crucial mandate, highlighted by recent approvals for two PDL1 diagnostic tests. Here, we discuss biomarkers for anti-PD1 therapy based on immunological, genetic and virological criteria. The unique biology of the CTLA4 immune checkpoint, compared with PD1, requires a different approach to biomarker development. Mechanism-based insights from such studies may guide the design of synergistic treatment combinations based on immune checkpoint blockade.

HemOnc Today Melanoma and Cutaneous Malignancies and American College of Cardiology

Key sessions at HemOnc Today covered systemic and locoregional use of immunotherapies. At the cardiology meeting, preventive strategies took center stage.

Immune checkpoint blockade: Releasing the brake towards hematological malignancies

Tumor cells utilize co-inhibitory molecules to avoid host immune destruction. Checkpoint blockade has emerged as a promising approach to treat cancer by restoring T cell effector function and breaking a tumor permissive microenvironment. Patients with hematological malignancies often have immune dysregulation, thus the role of checkpoint blockade in treatment of these neoplasms is particularly intriguing. In early trials, antibodies targeting cytotoxic T lymphocyte antigen 4 (CTLA-4) or the programmed death 1 (PD-1) signaling pathway have displayed significant efficacy with minimal toxicity in patients with relapsed and refractory hematological neoplasms. In this review, we provide evidence of dysregulation of CTLA-4 and PD-1/PD-Ls in the context of several major types of hematological neoplasms and summarize relevant clinical practice points for checkpoint blockade. The preclinical rationale and preliminary clinical data of potential combination approaches designed to optimize checkpoint antagonists are well presented.

Anti-CD137 monoclonal antibodies and adoptive T cell therapy: a perfect marriage?

CD137(4-1BB) costimulation and adoptive T cell therapy strongly synergize in terms of achieving maximal efficacy against experimental cancers. These costimulatory biological functions of CD137 have been exploited by means of introducing the CD137 signaling domain in clinically successful chimeric antigen receptors and to more efficiently expand T cells in culture. In addition, immunomagnetic sorting of CD137-positive T cells among tumor-infiltrating lymphocytes selects for the fittest antitumor T lymphocytes for subsequent cultures. In mouse models, co-infusion of both agonist antibodies and T cells attains marked synergistic effects that result from more focused and intense cytolytic activity visualized under in vivo microscopy and from more efficient entrance of T cells into the tumor through the vasculature. These several levels of dynamic interaction between adoptive T cell therapy and CD137 offer much opportunity to raise the efficacy of current cancer immunotherapies.

Silymarin suppressed lung cancer growth in mice via inhibiting myeloid-derived suppressor cells

In this study, we investigated the antitumor activity of Silymarin in a mouse model of colon cancer xenograft of Lewis lung cancer (LLC) cells. Silymarin significantly suppressed tumor growth and induced apoptosis of cells in tumor tissues at a dose of 25 and 50mg/kg. Silymarin treatment enhanced the infiltration and function of CD8(+) T cells. In the meantime, Silymarin decreased the level of IL-10 while elevated the level of IL-2 and IFN-γ in the serum of tumor-bearing mice. Finally, Silymarin reduced the proportion of myeloid-derived suppressor cells (MDSC) in the tumor tissue and also the mRNA expressions of inducible nitric oxide synthases-2 (iNOS2), arginase-1 (Arg-1) and MMP9, which indicated that the function of MDSC in tumor tissues were suppressed. Altogether, our data here showed that Silymarin inhibited the MDSC and promoted the infiltration and function of CD8(+) T cells thus suppressed the growth of LLC xenografts, which provides evidence for the possible use of Silymarin against lung cancer.

Data Interoperability of Whole Exome Sequencing (WES) Based Mutational Burden Estimates from Different Laboratories

Immune checkpoint inhibitors, which unleash a patient’s own T cells to kill tumors, are revolutionizing cancer treatment. Several independent studies suggest that higher non-synonymous mutational burden assessed by whole exome sequencing (WES) in tumors is associated with improved objective response, durable clinical benefit, and progression-free survival in immune checkpoint inhibitors treatment. Next-generation sequencing (NGS) is a promising technology being used in the clinic to direct patient treatment. Cancer genome WES poses a unique challenge due to tumor heterogeneity and sequencing artifacts introduced by formalin-fixed, paraffin-embedded (FFPE) tissue. In order to evaluate the data interoperability of WES data from different sources to survey tumor mutational landscape, we compared WES data of several tumor/normal matched samples from five commercial vendors. A large data discrepancy was observed from vendors’ self-reported data. Independent data analysis from vendors’ raw NGS data shows that whole exome sequencing data from qualified vendors can be combined and analyzed uniformly to derive comparable quantitative estimates of tumor mutational burden.

Efficacy and toxicity of treatment with the anti-CTLA-4 antibody ipilimumab in patients with metastatic melanoma after prior anti-PD-1 therapy

Background:

Recent phase III clinical trials have established the superiority of the anti-PD-1 antibodies pembrolizumab and nivolumab over the anti-CTLA-4 antibody ipilimumab in the first-line treatment of patients with advanced melanoma. Ipilimumab will be considered for second-line treatment after the failure of anti-PD-1 therapy.

Methods:

We retrospectively identified a cohort of 40 patients with metastatic melanoma who received single-agent anti-PD-1 therapy with pembrolizumab or nivolumab and were treated on progression with ipilimumab at a dose of 3 mg kg⁻¹ for a maximum of four doses.

Results:

Ten percent of patients achieved an objective response to ipilimumab, and an additional 8% experienced prolonged (>6 months) stable disease. Thirty-five percent of patients developed grade 3–5 immune-related toxicity associated with ipilimumab therapy. The most common high-grade immune-related toxicity was diarrhoea. Three patients (7%) developed grade 3–5 pneumonitis leading to death in one patient.

Conclusions:

Ipilimumab therapy can induce responses in patients who fail the anti-PD-1 therapy with response rates comparable to previous reports. There appears to be an increased frequency of high-grade immune-related adverse events including pneumonitis that warrants close surveillance.

Summary and Recommendations from the National Cancer Institute's Clinical Trials Planning Meeting on Novel Therapeutics for Non-Muscle Invasive Bladder Cancer

The NCI Bladder Cancer Task Force convened a Clinical Trials Planning Meeting (CTPM) Workshop focused on Novel Therapeutics for Non-Muscle Invasive Bladder Cancer (NMIBC). Meeting attendees included a broad and multi-disciplinary group of clinical and research stakeholders and included leaders from NCI, FDA, National Clinical Trials Network (NCTN), advocacy and the pharmaceutical and biotech industry. The meeting goals and objectives were to: 1) create a collaborative environment in which the greater bladder research community can pursue future optimally designed novel clinical trials focused on the theme of molecular targeted and immune-based therapies in NMIBC; 2) frame the clinical and translational questions that are of highest priority; and 3) develop two clinical trial designs focusing on immunotherapy and molecular targeted therapy. Despite successful development and implementation of large Phase II and Phase III trials in bladder and upper urinary tract cancers, there are no active and accruing trials in the NMIBC space within the NCTN. Disappointingly, there has been only one new FDA approved drug (Valrubicin) in any bladder cancer disease state since 1998. Although genomic-based data for bladder cancer are increasingly available, translating these discoveries into practice changing treatment is still to come. Recently, major efforts in defining the genomic characteristics of NMIBC have been achieved. Aligned with these data is the growing number of targeted therapy agents approved and/or in development in other organ site cancers and the multiple similarities of bladder cancer with molecular subtypes in these other cancers. Additionally, although bladder cancer is one of the more immunogenic tumors, some tumors have the ability to attenuate or eliminate host immune responses. Two trial concepts emerged from the meeting including a window of opportunity trial (Phase 0) testing an FGFR3 inhibitor and a second multi-arm multi-stage trial testing combinations of BCG or radiotherapy and immunomodulatory agents in patients who recur after induction BCG (BCG failure).

Elevated Levels of SOX10 in Serum from Vitiligo and Melanoma Patients, Analyzed by Proximity Ligation Assay

Background

The diagnosis of malignant melanoma currently relies on clinical inspection of the skin surface and on the histopathological status of the excised tumor. The serum marker S100B is used for prognostic estimates at later stages of the disease, but analyses are marred by false positives and inadequate sensitivity in predicting relapsing disorder.

Objectives

To investigate SOX10 as a potential biomarker for melanoma and vitiligo.

Methods

In this study we have applied proximity ligation assay (PLA) to detect the transcription factor SOX10 as a possible serum marker for melanoma. We studied a cohort of 110 melanoma patients. We further investigated a second cohort of 85 patients with vitiligo, which is a disease that also affects melanocytes.

Results

The specificity of the SOX10 assay in serum was high, with only 1% of healthy blood donors being positive. In contrast, elevated serum SOX10 was found with high frequency among vitiligo and melanoma patients. In patients with metastases, lack of SOX10 detection was associated with treatment benefit. In two responding patients, a change from SOX10 positivity to undetectable levels was seen before the response was evident clinically.

Conclusions

We show for the first time that SOX10 represents a promising new serum melanoma marker for detection of early stage disease, complementing the established S100B marker. Our findings imply that SOX10 can be used to monitor responses to treatment and to assess if the treatment is of benefit at stages earlier than what is possible radiologically.

Timing of CSF-1/CSF-1R signaling blockade is critical to improving responses to CTLA-4 based immunotherapy

Colony stimulating factor-1 (CSF-1) is produced by a variety of cancers and recruits myeloid cells that suppress antitumor immunity, including myeloid-derived suppressor cells (MDSCs.) Here, we show that both CSF-1 and its receptor (CSF-1R) are frequently expressed in tumors from cancer patients, and that this expression correlates with tumor-infiltration of MDSCs. Furthermore, we demonstrate that these tumor-infiltrating MDSCs are highly immunosuppressive but can be reprogrammed toward an antitumor phenotype in vitro upon CSF-1/CSF-1R signaling blockade. Supporting these findings, we show that inhibition of CSF-1/CSF-1R signaling using an anti-CSF-1R antibody can regulate both the number and the function of MDSCs in murine tumors in vivo. We further find that treatment with anti-CSF-1R antibody induces antitumor T-cell responses and tumor regression in multiple tumor models when combined with CTLA-4 blockade therapy. However, this occurs only when administered after or concurrent with CTLA-4 blockade, indicating that timing of each therapeutic intervention is critical for optimal antitumor responses. Importantly, MDSCs present within murine tumors after CTLA-4 blockade showed increased expression of CSF-1R and were capable of suppressing T cell proliferation, and CSF-1/CSF-1R expression in the human tumors was not reduced after treatment with CTLA-4 blockade immunotherapy. Taken together, our findings suggest that CSF-1R-expressing MDSCs can be targeted to modulate the tumor microenvironment and that timing of CSF-1/CSF-1R signaling blockade is critical to improving responses to checkpoint based immunotherapy.

SIGNIFICANCE

Infiltration by immunosuppressive myeloid cells contributes to tumor immune escape and can render patients resistant or less responsive to therapeutic intervention with checkpoint blocking antibodies. Our data demonstrate that blocking CSF-1/CSF-1R signaling using a monoclonal antibody directed to CSF-1R can regulate both the number and function of tumor-infiltrating immunosuppressive myeloid cells. In addition, our findings suggest that reprogramming myeloid responses may be a key in effectively enhancing cancer immunotherapy, offering several new potential combination therapies for future clinical testing. More importantly for clinical trial design, the timing of these interventions is critical to achieving improved tumor protection.

The Long and Winding Road: From the High-Affinity Choline Uptake Site to Clinical Trials for Malignant Brain Tumors

Malignant brain tumors are one of the most lethal cancers. They originate from glial cells which infiltrate throughout the brain. Current standard of care involves surgical resection, radiotherapy, and chemotherapy; median survival is currently ~14-20 months postdiagnosis. Given that the brain immune system is deficient in priming systemic immune responses to glioma antigens, we proposed to reconstitute the brain immune system to achieve immunological priming from within the brain. Two adenoviral vectors are injected into the resection cavity or remaining tumor. One adenoviral vector expresses the HSV-1-derived thymidine kinase which converts ganciclovir into a compound only cytotoxic to dividing glioma cells. The second adenovirus expresses the cytokine fms-like tyrosine kinase 3 ligand (Flt3L). Flt3L differentiates precursors into dendritic cells and acts as a chemokine that attracts dendritic cells to the brain. HSV-1/ganciclovir killing of tumor cells releases tumor antigens that are taken up by dendritic cells within the brain tumor microenvironment. Tumor killing also releases HMGB1, an endogenous TLR2 agonist that activates dendritic cells. HMGB1-activated dendritic cells, loaded with glioma antigens, migrate to cervical lymph nodes to stimulate a systemic CD8+ T cells cytotoxic immune response against glioma. This immune response is specific to glioma tumors, induces immunological memory, and does neither cause brain toxicity nor autoimmune responses. An IND was granted by the FDA on 4/7/2011. A Phase I, first in person trial, to test whether reengineering the brain immune system is potentially therapeutic is ongoing.

SCIB2, an antibody DNA vaccine encoding NY-ESO-1 epitopes, induces potent antitumor immunity which is further enhanced by checkpoint blockade

Checkpoint blockade has demonstrated promising antitumor responses in approximately 10-40% of patients. However, the majority of patients do not make a productive immune response to their tumors and do not respond to checkpoint blockade. These patients may benefit from an effective vaccine that stimulates high-avidity T cell responses in combination with checkpoint blockade. We have previously shown that incorporating TRP-2 and gp100 epitopes into the CDR regions of a human IgG1 DNA (ImmunoBody®: IB) results in significant tumor regression both in animal models and patients. This vaccination strategy is superior to others as it targets antigen to antigen-presenting cells and stimulates high-avidity T cell responses. To broaden the application of this vaccination strategy, 16 NY-ESO-1 epitopes, covering over 80% of HLA phenotypes, were incorporated into the IB (SCIB2). They produced higher frequency and avidity T cell responses than peptide vaccination. These T cells were of sufficient avidity to kill NY-ESO-1-expressing tumor cells, and in vivo controlled the growth of established B16-NY-ESO-1 tumors, resulting in long-term survival (35%). When SCIB2 was given in combination with Treg depletion, CTLA-4 blockade or PD-1 blockade, long-term survival from established tumors was significantly enhanced to 56, 67 and 100%, respectively. Translating these responses into the clinic by using a combination of SCIB2 vaccination and checkpoint blockade can only further improve clinical responses.

Immunotherapy for lung cancer

Treatment of lung cancer remains a challenge, and lung cancer is still the leading cause of cancer-related mortality. Immunotherapy has previously failed in lung cancer but has recently emerged as a very effective new therapy, and there is now growing worldwide enthusiasm in cancer immunotherapy. We summarize why immune checkpoint blockade therapies have generated efficacious and durable responses in clinical trials and why this has reignited interest in this field. Cancer vaccines have also been explored in the past with marginal success. Identification of optimal candidate neoantigens may improve cancer vaccine efficacy and may pave the way to personalized immunotherapy, alone or in combination with other immunotherapy such as immune checkpoint blockade. Understanding the steps in immune recognition and eradication of cancer cells is vital to understanding why previous immunotherapies failed and how current therapies can be used optimally. We hold an optimistic view for the future prospect in lung cancer immunotherapy.

Targeting NK Cells for Anticancer Immunotherapy: Clinical and Preclinical Approaches

The recent success of checkpoint blockade has highlighted the potential of immunotherapy approaches for cancer treatment. Although the majority of approved immunotherapy drugs target T cell subsets, it is appreciated that other components of the immune system have important roles in tumor immune surveillance as well and thus represent promising additional targets for immunotherapy. Natural killer (NK) cells are the body’s first line of defense against infected or transformed cells, as they kill target cells in an antigen-independent manner. Although several studies have clearly demonstrated the active role of NK cells in cancer immune surveillance, only few clinically approved therapies currently exist that harness their potential. Our increased understanding of NK cell biology over the past few years has renewed the interest in NK cell-based anticancer therapies, which has lead to a steady increase of NK cell-based clinical and preclinical trials. Here, the role of NK cells in cancer immune surveillance is summarized, and several novel approaches to enhance NK cell cytotoxicity against cancer are discussed.

Phase II Study of Autologous Monocyte-Derived mRNA Electroporated Dendritic Cells (TriMixDC-MEL) Plus Ipilimumab in Patients With Pretreated Advanced Melanoma

Purpose

Autologous monocyte-derived dendritic cells (DCs) electroporated with synthetic mRNA (TriMixDC-MEL) are immunogenic and have antitumor activity as a monotherapy in patients with pretreated advanced melanoma. Ipilimumab, an immunoglobulin G1 monoclonal antibody directed against the cytotoxic T-lymphocyte-associated protein 4 receptor that counteracts physiologic suppression of T-cell function, improves the overall survival of patients with advanced melanoma. This phase II study investigated the combination of TriMixDC-MEL and ipilimumab in patients with pretreated advanced melanoma.

Patients and Methods

Thirty-nine patients were treated with TriMixDC-MEL (4 × 106 cells administered intradermally and 20 × 106 cells administered intravenously) plus ipilimumab (10 mg/kg every 3 weeks for a total of four administrations, followed by maintenance therapy every 12 weeks in patients who remained progression free). Six-month disease control rate according to the immune-related response criteria served as the primary end point.

Results

The 6-month disease control rate was 51% (95% CI, 36% to 67%), and the overall tumor response rate was 38% (including eight complete and seven partial responses). Seven complete responses and one partial tumor response are ongoing after a median follow-up time of 36 months (range, 22 to 43 months). The most common treatment-related adverse events (all grades) consisted of local DC injection site skin reactions (100%), transient post–DC infusion chills (38%) and flu-like symptoms (84%), dermatitis (64%), hepatitis (13%), hypophysitis (15%), and diarrhea/colitis (15%). Grade 3 or 4 immune-related adverse events occurred in 36% of patients. There was no grade 5 adverse event.

Conclusion

The combination of TriMixDC-MEL and ipilimumab is tolerable and results in an encouraging rate of highly durable tumor responses in patients with pretreated advanced melanoma.

Long-Term Progression-Free and Overall Survival in Two Melanoma Patients Treated with Patient-Specific Therapeutic Vaccine Eltrapuldencel-T After Resection of a Solitary Liver Metastasis

Hepatic metastases from melanoma are usually associated with recurrence and short survival, even in patients with a solitary metastasis. Two patients, one with melanoma of unknown primary and one with ocular melanoma, underwent resection of a solitary liver metastasis followed by treatment with eltrapuldencel-T, a patient-specific therapeutic vaccine consisting of autologous dendritic cells loaded with antigens from irradiated melanoma cells obtained from an autologous tumor cell line. Following surgical resection, the ocular melanoma patient remained progression free for more than 4.5 years and was known to be alive more than 8.5 years later, while the other patient, who previously had experienced lung and small bowel metastases, has remained disease free and is alive more than 12 years later. These two cases illustrate how immunotherapies designed to induce immune responses to tumor-associated antigens (TAA), as opposed to releasing previously existing responses to TAA that have been suppressed, may also enhance long-term disease control and survival.

Adapting Cancer Immunotherapy Models for the Real World

Early experiments in mice predicted the success of checkpoint blockade immunotherapy in cancer patients. However, these same animal studies failed to accurately predict many of the limitations and toxicities of treatment. One of the likely reasons for this discrepancy is the nearly universal use of young healthy mice, which stand in stark contrast to diverse patient populations varying in age, weight, diet, and hygiene. Because these variables impact immunity and metabolism, they also influence outcomes during immunotherapy and should be incorporated into the study design of preclinical experiments. Here, we discuss recent findings that highlight how efficacy and toxicity of cancer immunotherapy are affected by patient variation, and how distinct host environments can be better modeled in animal studies.

The significance and therapeutic potential of PD-1 and its ligands in ovarian cancer: A systematic review

Surgery, radiotherapy and chemotherapy are the mainstay of malignant cancer treatments. However, with the development of immunology, the emerging immunotherapy represents a rational and alternative approach for the treatment of human cancer, including ovarian cancer (OC). Based on a body of evidence and the clinical success of immunotherapy in many malignancies, it is confirmed that blocking the programmed death 1 (PD-1) and its ligands in OC is feasible and valid both in animal models and patients. Immunotherapy may play a significant role in the future clinical management and improve the prognosis of OC. This review will focus on the biological functions, treatment response, toxicity and viable target of PD-1 and its ligands in OC. Recognition of the multiple functions of PD-1 and its ligands in ovarian cancer will serve to deepen our understanding of the nature of OC, develop novel immunotherapy approaches and discover possible diagnostic and prognostic biomarkers in future clinical decisions.

Inflammation-Induced Plasticity in Melanoma Therapy and Metastasis

Phenotype switching contributes to nongenomic heterogeneity in melanoma and other cancers. These dynamic and in part reversible phenotype changes impose diagnostic and therapeutic challenges. Understanding the reciprocal coevolution of melanoma and immune cell phenotypes during disease progression and in response to therapy is a prerequisite to improve current treatment strategies. Here we discuss how proinflammatory signals promote melanoma cell plasticity and govern interactions of melanoma and immune cells in the tumor microenvironment. We examine phenotypic plasticity and heterogeneity in different melanoma mouse models with respect to their utility for translational research and emphasize the interplay between melanoma cells and neutrophils as a critical driver of metastasis.

Preclinical exploration of combining plasmacytoid and myeloid dendritic cell vaccination with BRAF inhibition

BACKGROUND

Melanoma is the most lethal type of skin cancer and its incidence is progressively increasing. The introductions of immunotherapy and targeted therapies have tremendously improved the treatment of melanoma. Selective inhibition of BRAF by vemurafenib results in objective clinical responses in around 50 % of patients suffering from BRAFV600 mutated melanoma. However, drug resistance often results in hampering long-term tumor control. Alternatively, immunotherapy by vaccination with natural dendritic cells (nDCs) demonstrated long-term tumor control in a proportion of patients. We postulate that the rapid tumor debulking by vemurafenib can synergize the long-term tumor control of nDC vaccination to result in an effective treatment modality in a large proportion of patients. Here, we investigated the feasibility of this combination by analyzing the effect of vemurafenib on the functionality of nDCs.

METHODS

Plasmacytoid DCs (pDCs) and myeloid DCs (mDCs) were isolated from PBMCs obtained from buffy coats from healthy volunteers or vemurafenib-treated melanoma patients. Maturation of pDCs, mDCs and immature monocyte-derived DCs was induced by R848 in the presence or absence of vemurafenib and analyzed by FACS. Cytokine production and T cell proliferation induced by mature DCs were analyzed.

RESULTS

Vemurafenib inhibited maturation and cytokine production of highly purified nDCs of healthy volunteers resulting in diminished allogeneic T cell proliferation. This deleterious effect of vemurafenib on nDC functionality was absent when total PBMCs were exposed to vemurafenib. In patients receiving vemurafenib, nDC functionality and T cell allostimulatory capacity were unaffected.

CONCLUSION

Although vemurafenib inhibited the functionality of purified nDC of healthy volunteers, this effect was not observed when nDCs were matured in the complete PBMC fraction. This might have been caused by increased vemurafenib uptake in absence of other cell types. In accordance, nDCs isolated from patients on active vemurafenib treatment showed no negative effects. In conclusion, our results pave the way for a combinatorial treatment strategy and, we propose that combining vemurafenib with nDC vaccination represent a powerful opportunity that deserves more investigation in the clinic.

Strategic Combinations: The Future of Oncolytic Virotherapy with Reovirus

The dominant cancer treatment modalities such as chemotherapy, radiotherapy, and even targeted kinase inhibitors and mAbs are limited by low efficacy, toxicity, and treatment-resistant tumor subclones. Oncolytic viral therapy offers a novel therapeutic strategy that has the potential to dramatically improve clinical outcomes. Reovirus, a double-stranded benign human RNA virus, is a leading candidate for therapeutic development and currently in phase III trials. Reovirus selectively targets transformed cells with activated Ras signaling pathways; Ras genes are some of the most frequently mutated oncogenes in human cancer and it is estimated that at least 30% of all human tumors exhibit aberrant Ras signaling. By targeting Ras-activated cells, reovirus can directly lyse cancer cells, disrupt tumor immunosuppressive mechanisms, reestablish multicellular immune surveillance, and generate robust antitumor responses. Reovirus therapy is currently being tested in combination with radiotherapy, chemotherapy, immunotherapy, and surgery. In this review, we discuss the current successes of these combinatorial therapeutic strategies and emphasize the importance of prioritizing combination oncolytic viral therapy as reovirus-based treatments progress in clinical development. Mol Cancer Ther; 15(5); 767-73. ©2016 AACR.

Cutaneous, gastrointestinal, hepatic, endocrine, and renal side-effects of anti-PD-1 therapy

BACKGROUND

Anti-programmed cell death receptor-1 (PD-1) antibodies represent an effective treatment option for metastatic melanoma as well as for other cancer entities. They act via blockade of the PD-1 receptor, an inhibitor of the T-cell effector mechanisms that limit immune responses against tumours. As reported for ipilimumab, the anti-PD-1 antibodies pembrolizumab and nivolumab can induce immune-related adverse events (irAEs). These side-effects affect skin, gastrointestinal tract, liver, endocrine system and other organ systems. Since life-threatening and fatal irAEs have been reported, adequate diagnosis and management are essential.

METHODS AND FINDINGS

In total, 496 patients with metastatic melanoma from 15 skin cancer centers were treated with pembrolizumab or nivolumab; 242 side-effects were described in 138 patients. In 116 of the 138 patients, side-effects affected the skin, gastrointestinal tract, liver, endocrine, and renal system. Rare side-effects included diabetes mellitus, lichen planus, and pancreas insufficiency due to pancreatitis.

CONCLUSION

Anti-PD1 antibodies can induce a plethora of irAEs. The knowledge of them will allow prompt diagnosis and improve the management resulting in decreased morbidity.

Enhanced Cancer Immunotherapy by Microneedle Patch-Assisted Delivery of Anti-PD1 Antibody

Despite recent advances in melanoma treatment through the use of anti-PD-1 (aPD1) immunotherapy, the efficacy of this method remains to be improved. Here we report an innovative self-degradable microneedle (MN) patch for the sustained delivery of aPD1 in a physiologically controllable manner. The microneedle is composed of biocompatible hyaluronic acid integrated with pH-sensitive dextran nanoparticles (NPs) that encapsulate aPD1 and glucose oxidase (GOx), which converts blood glucose to gluconic acid. The generation of acidic environment promotes the self-dissociation of NPs and subsequently results in the substantial release of aPD1. We find that a single administration of the MN patch induces robust immune responses in a B16F10 mouse melanoma model compared to MN without degradation trigger or intratumoral injection of free aPD1 with the same dose. Moreover, this administration strategy can integrate with other immunomodulators (such as anti-CTLA-4) to achieve combination therapy for enhancing antitumor efficacy.

Neurological, respiratory, musculoskeletal, cardiac and ocular side-effects of anti-PD-1 therapy

BACKGROUND

Anti-programmed cell death 1 (PD-1) antibodies represent an effective treatment option for metastatic melanoma and other cancer entities. They act via blockade of the PD-1 receptor, an inhibitor of the T-cell effector mechanisms that limit immune responses against tumours. As reported for ipilimumab, the anti-PD-1 antibodies pembrolizumab and nivolumab can induce immune-related adverse events (irAEs). These side-effects can involve skin, gastrointestinal tract, liver, the endocrine system and other organ systems. Since life-threatening and fatal irAEs have been reported, adequate diagnosis and management are essential.

METHODS AND FINDINGS

In total, 496 patients with metastatic melanoma from 15 skin cancer centres were treated with pembrolizumab or nivolumab. Two hundred forty two side-effects in 138 patients have been analysed. In 77 of the 138 patients side-effects affected the nervous system, respiratory tract, musculoskeletal system, heart, blood and eyes. Not yet reported side-effects such as meningo-(radiculitis), polyradiculitis, cardiac arrhythmia, asystolia, and paresis have been observed. Rare and difficult to manage side-effects such as myasthenia gravis are described in detail.

CONCLUSION

Anti-PD-1 antibodies can induce a plethora of irAEs. The knowledge of them will allow prompt diagnosis and improve the management resulting in decreased morbidity.

Combination dabrafenib and trametinib in the management of advanced melanoma with BRAFV600 mutations

INTRODUCTION

In the 40-50% of advanced melanoma patients with tumors harboring BRAF V600E and V600 K mutations, BRAF inhibitors such as dabrafenib are a highly effective treatment. However, most patients develop resistance after several months on treatment. The addition of a MEK inhibitor, such as trametinib, to BRAF inhibition mitigates one key pathway of resistance, further increasing response rates and improving survival.

AREAS COVERED

This article summarizes the mechanism of action of the combination of dabrafenib and trametinib, its evolution through Phase I, II and III clinical trials and discusses its current use in the management of patients with advanced melanoma.

EXPERT OPINION

Combination therapy with dabrafenib and trametinib improves response rate, progression-free survival and overall survival when compared to dabrafenib or vemurafenib alone. The addition of trametinib to dabrafenib changes the adverse event profile, making hyperkeratosis and cutaneous squamous cell carcinomas less common but side effects such as fever and nausea more common. How dabrafenib/trametinib is best sequenced with other effective treatments such as immune checkpoint blockade remains uncertain.

Embracing rejection: Immunologic trends in brain metastasis

Brain metastases represent the most common type of brain tumor. These tumors offer a dismal prognosis and significantly impact quality of life for patients. Their capacity for central nervous system (CNS) invasion is dependent upon induced disruptions to the blood-brain barrier (BBB), alterations to the brain microenvironment, and mechanisms for escaping CNS immunosurveillance. In the emerging era of immunotherapy, understanding how metastases are influenced by the immunologic peculiarities of the CNS will be crucial to forging therapeutic advances. In this review, the immunology of brain metastasis is explored.

Off-label use of targeted therapies in oncology

Off-label use is defined by the prescription of a marketed drug outside the conditions described in the summary of product characteristics. In oncology, off-label prescribing of targeted therapies may occur in patients with other tumor types expressing the same target. Agents associated to phenotypic approaches such as therapies against the tumoral vasculature (anti-angiogenic drugs) and new immunotherapies (checkpoint inhibitors) also carry the potential of alternative indications or combinations. Off-label use of targeted therapies is little documented and appears to be in the same range than that regarding older drugs with wide variations among agents. When compared with older agents, off-label use of targeted therapies is probably more rational through tumoral genotyping but is faced with a limited clinical support, reimbursement challenges related to the very high pricing and the cost of genotyping or molecular profiling, when applicable.

Targeting the tumor microenvironment: removing obstruction to anticancer immune responses and immunotherapy

The tumor microenvironment (TME) is an integral part of cancer. Recognition of the essential nature of the TME in cancer evolution has led to a shift from a tumor cell-centered view of cancer development to the concept of a complex tumor ecosystem that supports tumor growth and metastatic dissemination. Accordingly, novel targets within the TME have been uncovered that can help direct and improve the actions of various cancer therapies, notably immunotherapies that work by potentiating host antitumor immune responses. Here, we review the composition of the TME, how this attenuates immunosurveillance, and discuss existing and potential strategies aimed at targeting cellular and molecular TME components.

Dissecting the multicellular ecosystem of metastatic melanoma by single-cell RNA-seq

To explore the distinct genotypic and phenotypic states of melanoma tumors, we applied single-cell RNA sequencing (RNA-seq) to 4645 single cells isolated from 19 patients, profiling malignant, immune, stromal, and endothelial cells. Malignant cells within the same tumor displayed transcriptional heterogeneity associated with the cell cycle, spatial context, and a drug-resistance program. In particular, all tumors harbored malignant cells from two distinct transcriptional cell states, such that tumors characterized by high levels of the MITF transcription factor also contained cells with low MITF and elevated levels of the AXL kinase. Single-cell analyses suggested distinct tumor microenvironmental patterns, including cell-to-cell interactions. Analysis of tumor-infiltrating T cells revealed exhaustion programs, their connection to T cell activation and clonal expansion, and their variability across patients. Overall, we begin to unravel the cellular ecosystem of tumors and how single-cell genomics offers insights with implications for both targeted and immune therapies.