Nivolumab for previously treated unresectable metastatic anal cancer (NCI9673): a multicentre, single-arm, phase 2 study

Targeting Programmed Cell Death -1 (PD-1) and Ligand (PD-L1): A new era in cancer active immunotherapy

Improved understanding of the immune system and its role in cancer development and progression has led to impressive advances in the field of cancer immunotherapy over the last decade. Whilst the field is rapidly evolving and the list of drugs receiving regulatory approval for the treatment of various cancers is fast growing, the group of PD1- PDL-1 inhibitors is establishing a leading role amongst immunomodulatory agents. PD1- PDL-1 inhibitors act against pathways involved in adaptive immune suppression resulting in immune checkpoint blockade. Within the last four years two PD-1 and three PD-L1 inhibitors have been utilized in clinical practice against a variety of malignancies. Focus was initially placed on targeting cancers considered immunogenic such as melanoma, renal and lung cancers but subsequently the application expanded to include amongst others Hodgkin Lymphoma, urothelial as well as head and neck cancer. This article provides a comprehensive review of the early and late phase trials that led to the regulatory approval of all five PD1- PDL-1 inhibitors in the corresponding cancer types. It presents available data on the combinations of PD1- PDL-1 inhibitors with other therapies (immunotherapy, targeted therapy and chemotherapy), the toxicity profile of the PD1- PDL-1 inhibitors and ongoing trials testing the efficacy of these agents in cancer types beyond those that have been addressed already. Finally, current and future challenges in the application of PD-1 and PD-L1 inhibitors are discussed with emphasis on the role of predictive biomarkers.

Recent advances in the management of anal cancer

Anal cancer is a rare condition, although its incidence has been increasing over the past several decades, particularly in women. The majority of anal cancers are squamous cell cancers and are linked with human papilloma virus (HPV) infection. Recent work in HPV basic science has delineated the mechanism by which the virus leads to the development of anal cancer. With widespread availability of an HPV vaccine since 2006, vaccination has become an important strategy for anal cancer prevention. However, in the US, there remain no guidelines for anal cancer screening. Treatment of anal cancer is dictated largely by accurate staging, which is generally accomplished with a combination of physical exam, magnetic resonance imaging, computed tomography, and positron emission tomography. Chemoradiation remains the mainstay of treatment for most patients, with surgery reserved for salvage therapy. Recent trials have identified the optimal use of available chemotherapeutics. Exciting developments in immune therapies targeting HPV oncoproteins as well as therapeutic vaccines may soon dramatically change the way patients with anal cancer are managed.

FOLFCIS Treatment and Genomic Correlates of Response in Advanced Anal Squamous Cell Cancer

BACKGROUND

Treatment of advanced anal squamous cell cancer (SCC) is usually with the combination of cisplatin and 5-fluorouracil, which is associated with heterogeneous responses across patients and significant toxicity. We examined the safety and efficacy of a modified schedule, FOLFCIS (leucovorin, fluorouracil, and cisplatin), and performed an integrated clinical and genomic analysis of anal SCC.

PATIENTS AND METHODS

We reviewed all patients with advanced anal SCC receiving first-line FOLFCIS chemotherapy - essentially a FOLFOX (leucovorin, fluorouracil, and oxaliplatin) schedule with cisplatin substituted for oxaliplatin - in our institution between 2007 and 2017, and performed deep sequencing to identify genomic markers of response and key genomic drivers.

RESULTS

Fifty-three patients with advanced anal SCC (48 metastatic; 5 unresectable, locally advanced) received first-line FOLFCIS during this period; all were platinum-naive. The response rate was 48% (95% confidence interval [CI], 32.6%-63%). With a median follow-up of 41.6 months, progression-free survival and overall survival were 7.1 months (95% CI, 4.4-8.6 months) and 22.1 months (95% CI, 16.9-28.1 months), respectively. Among all patients with advanced anal SCC that underwent sequencing during the study period, the most frequent genomic alterations consisted of chromosome 3q amplification (51%) and mutations in PIK3CA (29%) and KMT2D (22%). No genomic alteration correlated with response to platinum-containing treatment. Although there were few cases, patients with human papillomavirus-negative anal SCC did not appear to benefit from FOLFCIS, and all harbored distinct genomic profiles with TP53, TERT promoter, and CDKN2A mutations.

CONCLUSIONS

FOLFCIS appears effective and safe as first-line chemotherapy in patients with advanced anal SCC and represents an alternative treatment option for these patients.

Prognostic Factors for Checkpoint Inhibitor Based Immunotherapy: An Update With New Evidences

Checkpoint inhibitor (CPI) based immunotherapy (i.e., anit-CTLA-4/PD-1/PD-L1 antibodies) can effectively prolong overall survival of patients across several cancer types at the advanced stage. However, only part of patients experience objective responses from such treatments, illustrating large individual differences in terms of both efficacy and adverse drug reactions. Through the observation on a series of CPI based clinical trials in independent patient cohorts, associations of multiple clinical and molecular characteristics with CPI response rate have been determined, including microenvironment, genomic alterations of the cancer cells, and even gut microbiota. A broad interest has been drawn to the question whether and how these prognostic factors can be used as biomarkers for optimal usage of CPIs in precision immunotherapy. Therefore, we reviewed the candidate prognostic factors identified by multiple trials and the experimental investigations, especially those reported in the recent 2 years, and described the possibilities and problems of them in routine clinical usage of cancer treatment as biomarkers.

Immune-checkpoint inhibitors to treat cancers in specific immunocompromised populations: a critical review

INTRODUCTION

Because of their efficacy against numerous cancers, immune-checkpoint inhibitors (ICIs), anti-cytotoxic T-lymphocyte antigen-4, and anti-programmed cell death monoclonal antibodies are being used ever more often in oncology. However, some patients were excluded from clinical trials because of their comorbidities despite their potentially higher cancer frequencies, as is the case for immunocompromised patients. Areas covered: We analyzed reported preclinical and clinical information and evaluated the risk/benefit ratio for four immunocompromised populations: people living with human immunodeficiency virus (PLHs), solid-organ transplant recipients, recipients of hematopoietic stem-cell allografts, and patients with autoimmune diseases. Expert commentary: Information available in the literature is fragmentary and scarce, making it difficult to evaluate the risk/benefit ratio. It can, nonetheless, be noted that ICI use in PLHs seems possible. For solid-organ transplant recipients, the risk for the graft seems elevated. For the other two populations, it is difficult to conclude at this time.

Complete response to ipilimumab and nivolumab therapy in a patient with extensive extrapulmonary high-grade small cell carcinoma of the pancreas and HIV infection

BACKGROUND

Immune checkpoint inhibitors (CPIs) have shown promising results in many solid tumors. There are limited data on the safety and efficacy of these drugs in HIV infected patients as they have traditionally been excluded from CPIs clinical trials.

CASE PRESENTATION

We present a case of an HIV-positive patient with extensive extrapulmonary high-grade small cell carcinoma who was treated with dual CPIs (nivolumab and ipilimumab) with a complete response to therapy and with a manageable safety profile. We performed a comprehensive literature review identifying 62 total HIV positive cases treated with CPIs showing this to be a potentially safe option in HIV-positive patients.

CONCLUSION

HIV infection is not an absolute contraindication to CPI therapy. Our case and others provide justification for ongoing trials of CPI therapy in patients with HIV infection, a group that has traditionally been excluded from clinical trials.

Keeping Tumors in Check: A Mechanistic Review of Clinical Response and Resistance to Immune Checkpoint Blockade in Cancer

Immune checkpoints are a diverse set of inhibitory signals to the immune system that play a functional role in adaptive immune response and self-tolerance. Dysregulation of these pathways is a vital mechanism in the avoidance of immune destruction by tumor cells. Immune checkpoint blockade (ICB) refers to targeted strategies to disrupt the tumor co-opted immune suppression to enhance anti-tumor immunity. Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death 1 (PD-1) are two immune checkpoints that have the widest range of antibody-based therapies. These therapies have gone from promising approaches to Food and Drug Administration-approved first- and second-line agents for a number of immunogenic cancers. The burgeoning investigations of ICB efficacy in blood and solid cancers have underscored the importance of identifying the predictors of response and resistance to ICB. Identification of response correlates is made complicated by the observations of mixed reactions, or different responses in multiple lesions from the same patient, and delayed responses that can occur over a year after the induction therapy. Factors that can influence response and resistance in ICB can illuminate underlying molecular mechanisms of immune activation and suppression. These same response predictors can guide the identification of patients who would benefit from ICB, reduce off-target immune-relate adverse events, and facilitate the use of combinatorial therapies to increase efficacy. Here we review the underlying principles of immune checkpoint therapy and results of single-agent ICB clinical trials, and summarize the predictors of response and resistance.

Preclinical Development of Oncolytic Immunovirotherapy for Treatment of HPVPOS Cancers

Immunotherapy for HPV^POS malignancies is attractive because well-defined, viral, non-self tumor antigens exist as targets. Several approaches to vaccinate therapeutically against HPV E6 and E7 antigens have been adopted, including viral platforms such as VSV. A major advantage of VSV expressing these antigens is that VSV also acts as an oncolytic virus, leading to direct tumor cell killing and induction of effective anti-E6 and anti-E7 T cell responses. We have also shown that addition of immune adjuvant genes, such as IFNβ, further enhances safety and/or efficacy of VSV-based oncolytic immunovirotherapies. However, multiple designs of the viral vector are possible—with respect to levels of immunogen expression and method of virus attenuation—and optimal designs have not previously been tested head-to-head. Here, we tested three different VSV engineered to express a non-oncogenic HPV16 E7/6 fusion protein for their immunotherapeutic and oncolytic properties. We assessed their profiles of efficacy and toxicity against HPV^POS and HPV^NEG murine tumor models and determined the optimal route of administration. Our data show that VSV is an excellent platform for the oncolytic immunovirotherapy of tumors expressing HPV target antigens, combining a balance of efficacy and safety suitable for evaluation in a first-in-human clinical trial.

Docetaxel, cisplatin, and fluorouracil chemotherapy for metastatic or unresectable locally recurrent anal squamous cell carcinoma (Epitopes-HPV02): a multicentre, single-arm, phase 2 study

BACKGROUND

The incidence of anal squamous cell carcinoma has been increasing markedly in the past few decades. Currently, there is no validated treatment for advanced-stage anal squamous cell carcinoma. Therefore, we aimed to validate the clinical activity and safety of docetaxel, cisplatin, and fluorouracil (DCF) chemotherapy in patients with metastatic or unresectable locally recurrent anal squamous cell carcinoma.

METHODS

We did a multicentre, single-arm, phase 2 study. We recruited patients from 25 academic hospitals, cancer research centres, and community hospitals in France who were aged 18 years or older with histologically confirmed anal squamous cell carcinoma, with metastatic disease or with unresectable local recurrence; an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1; and with at least one evaluable lesion according to the Response Evaluation Criteria in Solid Tumors (version 1.1). Chemotherapy-naive patients received either six cycles of standard DCF (75 mg/m² docetaxel and 75 mg/m² cisplatin on day 1 and 750 mg/m² per day of fluorouracil for 5 days, every 3 weeks) or eight cycles of modified DCF (40 mg/m² docetaxel and 40 mg/m² cisplatin on day 1 and 1200 mg/m² per day of fluorouracil for 2 days, every 2 weeks), which were administered intravenously. The choice between the standard versus modified regimens was recommended based on, but not limited to, age (≤75 years vs >75 years) and ECOG performance status (0 vs 1). The primary endpoint was investigator-assessed progression-free survival at 12 months from the first DCF cycle; for the primary endpoint to be met, at least 11 (17%) of 66 enrolled patients had to be alive without disease progression at 12 months. Efficacy and safety analyses were done in a modified intention-to-treat population, defined as all patients who were evaluable for progression at 12 months who received at least one cycle of DCF. This trial is registered at ClinicalTrials.gov, number NCT02402842, and the final results are presented here.

FINDINGS

Between Sept 17, 2014, and Dec 7, 2016, we enrolled 69 patients. Of these patients, three did not receive DCF. Of the 66 patients who received treatment, 36 received the standard DCF regimen and 30 received modified DCF. The primary endpoint was met: 31 (47%) of 66 patients were alive and progression free at 12 months. 22 (61%) of 36 patients who received the standard DCF regimen and 18 (60%) of 30 patients who received the modified DCF regimen had disease progression at data cutoff. 46 (70%) of 66 patients had at least one grade 3-4 adverse event (30 [83%] of 36 in the standard DCF regimen and 16 [53%] of 30 in the modified DCF regimen). The most common grade 3-4 adverse events were neutropenia (15 [23%]; eight [22%] for standard DCF vs seven [23%] for modified DCF), diarrhoea (12 [18%]; nine [25%] vs three [10%]), asthenia (ten [15%]; eight [22%] vs two [7%]), anaemia (ten [15%]; six [17%] vs four [13%]), lymphopenia (eight [12%]; three [8%] vs five [17%]), mucositis (seven [11%]; seven [19%] vs none), and vomiting (seven [11%]; five [14%] vs two [7%]). No grade 4 non-haematological adverse events and febrile neutropenia were observed with modified DCF, whereas three (8%) grade 4 non-haematological adverse events and five (14%) cases of febrile neutropenia were reported with standard DCF. 97 serious adverse events were reported (69 in patients who received the standard DCF regimen [61 drug-related] and 28 in those given the modified DCF regimen [14 drug-related]). No treatment-related deaths were recorded.

INTERPRETATION

Compared with standard DCF, modified DCF provided long-lasting response with good tolerability in patients with metastatic or unresectable locally recurrent anal squamous cell carcinoma with ECOG performance status of 0-1 in the first-line setting, and therefore could be considered as a new standard of care for these patients. Regarding the elevated risk of high-grade and serious adverse events and febrile neutropenia, standard DCF cannot be recommended in this situation.

FUNDING

Besançon University Hospital and Ligue contre le cancer Grand-Est.

Pan-cancer adaptive immune resistance as defined by the Tumor Inflammation Signature (TIS): results from The Cancer Genome Atlas (TCGA)

The Tumor Inflammation Signature (TIS) is an investigational use only (IUO) 18-gene signature that measures a pre-existing but suppressed adaptive immune response within tumors. The TIS has been shown to enrich for patients who respond to the anti-PD1 agent pembrolizumab. To explore this immune phenotype within and across tumor types, we applied the TIS algorithm to over 9000 tumor gene expression profiles downloaded from The Cancer Genome Atlas (TCGA). As expected based on prior evidence, tumors with known clinical sensitivity to anti-programmed cell death protein 1 (PD-1) blockade had higher average TIS scores. Furthermore, TIS scores were more variable within than between tumor types, and within each tumor type a subset of patients with elevated scores was identifiable although with different prevalence associated with each tumor type, the latter consistent with the observed clinical responsiveness to anti PD-1 blockade. Notably, TIS scores only minimally correlated with mutation load in most tumors and ranking tumors by median TIS score showed differing association to clinical sensitivity to PD-1/PD-1 ligand 1 (PD-L1) blockade than ranking of the same tumors by mutation load. The expression patterns of the TIS algorithm genes were conserved across tumor types yet appeared to be minimally prognostic in most cancers, consistent with the TIS score serving as a pan-cancer measurement of the inflamed tumor phenotype. Characterization of the prevalence and variability of TIS will lead to increased understanding of the immune status of untreated tumors and may lead to improved indication selection for testing immunotherapy agents.

Skin microbiota-host interactions

The skin is a complex and dynamic ecosystem that is inhabited by bacteria, archaea, fungi and viruses. These microbes-collectively referred to as the skin microbiota-are fundamental to skin physiology and immunity. Interactions between skin microbes and the host can fall anywhere along the continuum between mutualism and pathogenicity. In this Review, we highlight how host-microbe interactions depend heavily on context, including the state of immune activation, host genetic predisposition, barrier status, microbe localization, and microbe-microbe interactions. We focus on how context shapes the complex dialogue between skin microbes and the host, and the consequences of this dialogue for health and disease.

Extended-Field Chemoradiation Therapy for Definitive Treatment of Anal Canal Squamous Cell Carcinoma Involving the Para-Aortic Lymph Nodes

PURPOSE

To report cancer control rates and adverse events (AEs) of curative-intent, extended-field chemoradiation therapy administered to patients with squamous cell carcinoma (SCC) of the anal canal presenting with distant metastasis limited to the para-aortic (PA) lymph nodes.

METHODS

This was a retrospective review of patients with SCC of the anal canal metastatic to the PA lymph nodes at initial diagnosis who were treated with curative-intent, extended-field chemoradiation therapy between September 2002 and February 2016 at two tertiary care centers. Outcomes assessed included treatment-related AEs (Common Terminology Criteria for Adverse Events, version 4.0), disease control (cumulative incidence estimates), and survival (Kaplan-Meier estimates).

RESULTS

Thirty patients were included. Involved and elective PA nodes were treated to median doses of 51 Gy (range 45-57.6) and 45 Gy (range 30.6-50.4) in 29 fractions (range 17-32). All patients received one of these concomitant regimens: 6 weekly cycles of cisplatin with 5-fluoruracil/capecitabine (5-FU) (n = 22), 2 cycles of mitomycin-C with 5-FU (n = 7), or daily capecitabine (n = 1). After a median follow-up period of 3.1 years, 18 patients (60%) remained alive and 17 patients were without evidence of anal cancer after definite and salvage treatments. Overall and disease-free survival at 3 years was 67% (95% CI 49%-89%) and 42% (95% CI 25%-69%). Fifteen (50%) patients experienced a recurrence at a median of 0.9 year (range 0.5-3.5 years). The predominant site of recurrence was distant metastases, with a 3-year cumulative incidence of 50% (95% CI 20%-68%). There was no acute grade 5 AE. Grade 3 to 4 gastrointestinal, dermatologic, and hematologic AEs occurred in 30%, 27%, and 20% of patients respectively.

CONCLUSIONS

Extended-field chemoradiation therapy is a potentially curative treatment option for patients presenting with SCC of the anal canal with metastases limited to the PA lymph nodes.

Systemic Therapies for Advanced Squamous Cell Anal Cancer

PURPOSE OF REVIEW

We aim to summarise the available evidence on systemic therapies for advanced anal cancer.

RECENT FINDINGS

There is no universal consensus on the management of this condition and the prognosis remains poor. Nevertheless, significant progress has been recently made including completion of the first, ever-conducted, randomised trial in the first-line setting, investigation of immunotherapy in the refractory setting and use of comprehensive genomic profiling for a better molecular characterisation of this disease and the identification of novel potential targets. The combination of a platinum agent and a fluoropyrimidine is generally considered the standard first-line treatment. Other cytotoxic agents, especially docetaxel and paclitaxel, have shown activity in both the chemotherapy-naive and chemo-refractory setting and are currently being investigated in clinical trials. Finally, further to the promising results of early clinical trials, immunotherapy with checkpoint inhibitors (i.e. nivolumab and pembrolizumab) is likely to become a standard second-line treatment option.

Landscape of Tumor Mutation Load, Mismatch Repair Deficiency, and PD-L1 Expression in a Large Patient Cohort of Gastrointestinal Cancers

The efficacy of immunotherapy varies widely among different gastrointestinal cancers. Response to immune checkpoint inhibitors is shown to correlate with tumor mutation load (TML), mismatch repair deficiency (dMMR) status, and programmed cell death-ligand 1 (PD-L1) expression. Herein, we quantify TML, dMMR, and PD-L1 expression and determine their interrelationship in gastrointestinal cancers. Here, a total of 4,125 tumors from 14 different gastrointestinal cancer sites were studied using validated assays. Next-generation sequencing was performed on genomic DNA isolated from formalin-fixed paraffin-embedded tumor specimens using the NextSeq platform. TML was calculated using only somatic nonsynonymous missense mutations sequenced with a 592-gene panel. Microsatellite instability (MSI) was assessed using direct analysis of altered known MSI loci in the target regions of the sequenced genes. PD-L1 expression was analyzed by IHC. Interestingly, right-sided colon and small-bowel adenocarcinomas had the highest prevalence of TML-high tumors (14.6% and 10.2%, respectively). Pancreatic neuroendocrine tumors and gastrointestinal stromal tumors had the lowest rates of TML-high (1.3% and 0%, respectively). TML-high was strongly associated with MSI-H (P < 0.0001). However, all TML-high anal cancers (8.3%) were microsatellite stable (MSS). Higher PD-L1 expression was more likely to be seen in MSI compared with MSS tumors (20.6% vs. 7.8%, P < 0.0001).Implications: TML-high rate varied widely among gastrointestinal cancers. Although MSI is conceivably the main driver for TML-high, other factors may be involved. Future clinical trials are needed to evaluate whether the integration of TML, MSI, and PD-L1 could better identify potential responders to immunotherapy. Mol Cancer Res; 16(5); 805-12. ©2018 AACR.

Evaluation of Prexasertib, a Checkpoint Kinase 1 Inhibitor, in a Phase Ib Study of Patients with Squamous Cell Carcinoma

Purpose: Prexasertib, a checkpoint kinase 1 inhibitor, demonstrated single-agent activity in patients with advanced squamous cell carcinoma (SCC) in the dose-escalation portion of a phase I study (NCT01115790). Monotherapy prexasertib was further evaluated in patients with advanced SCC.Patients and Methods: Patients were given prexasertib 105 mg/m² as a 1-hour infusion on day 1 of a 14-day cycle. Expansion cohorts were defined by tumor and treatment line. Safety, tolerability, efficacy, and exploratory biomarkers were analyzed.Results: Prexasertib was given to 101 patients, including 26 with SCC of the anus, 57 with SCC of the head and neck (SCCHN), and 16 with squamous cell non-small cell lung cancer (sqNSCLC). Patients were heavily pretreated (49% ≥3 prior regimens). The most common treatment-related adverse event was grade 4 neutropenia (71%); 12% of patients had febrile neutropenia. Median progression-free survival was 2.8 months [90% confidence interval (CI), 1.9-4.2] for SCC of the anus, 1.6 months (90% CI, 1.4-2.8) for SCCHN, and 3.0 months (90% CI, 1.4-3.9) for sqNSCLC. The clinical benefit rate at 3 months (complete response + partial response + stable disease) across tumors was 29% (23% SCC of the anus, 28% SCCHN, 44% sqNSCLC). Four patients with SCC of the anus had partial or complete response [overall response rate (ORR) = 15%], and three patients with SCCHN had partial response (ORR = 5%). Biomarker analyses focused on genes that altered DNA damage response or increased replication stress.Conclusions: Prexasertib demonstrated an acceptable safety profile and single-agent activity in patients with advanced SCC. The prexasertib maximum-tolerated dose of 105 mg/m² was confirmed as the recommended phase II dose. Clin Cancer Res; 24(14); 3263-72. ©2018 AACR.

Importance of immune monitoring approaches and the use of immune checkpoints for the treatment of diffuse intrinsic pontine glioma: From bench to clinic and vice versa (Review)

On the basis of immunological results, it is not in doubt that the immune system is able to recognize and eliminate transformed cells. A plethora of studies have investigated the immune system of patients with cancer and how it is prone to immunosuppression, due in part to the decrease in lymphocyte proliferation and cytotoxic activity. The series of experiments published following the demonstration by Dr Allison's group of the potential effect of anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) paved the way for a new perception in cancer immunotherapy: Immune checkpoints. Several T cell-co-stimulatory molecules including cluster of differentiation (CD)28, inducible T cell co-stimulatory, 4-1BB, OX40, glucocorticoid-induced tumor necrosis factor receptor-related gene and CD27, and inhibitory molecules including T cell immunoglobulin and mucin domain-containing-3, programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1), V-domain immunoglobulin suppressor of T cells activation, T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain, and B and T lymphocyte attenuator have been described in regulating T cell functions, and have been demonstrated to be essential targets in immunotherapy. In preclinical studies, glioblastoma multiforme, a high-grade glioma, the monotherapy targeting PD-1/PD-L1 and CTLA-4 resulted in increased survival times. An improved understanding of the pharmacodynamics and immune monitoring on glioma cancers, particularly in diffuse intrinsic pontine glioma (DIPG), an orphan type of cancer, is expected to have a major contribution to the development of novel therapeutic approaches. On the basis of the recent preclinical and clinical studies of glioma, but not of DIPG, the present review makes a claim for the importance of investigating the tumor microenvironment, the immune response and the use of immune checkpoints (agonists or antagonists) in preclinical/clinical DIPG samples by immune monitoring approaches and high-dimensional analysis. Evaluating the potential predictive and correlative biomarkers in preclinical and clinical studies may assist in answering certain crucial questions that may be useful to improve the clinical response in patients with DIPG.

Anal squamous cell carcinoma - State of the art management and future perspectives

Anal squamous cell carcinoma (ASCC) is associated with infection with high-risk strains of human papilloma virus (HPV) in 70-90% of cases and a rise in incidence has been observed in the last decades. Definitive chemoradiotherapy (CRT) using 5-fluorouracil and mitomycin C constitutes the standard treatment for localized disease, but about 30% of patients do not respond or relapse locally. Phase I/II trials testing targeted agents, such as epidermal-growth-factor receptor (EGFR) inhibitors, have failed to improve clinical outcome and resulted in increased toxicities. Modern imaging methods and biomarkers, also in the context of HPV status, should be further explored to improve patient stratification. In the present review, we will discuss the current clinical evidence and future perspectives in the management of ASCC. HPV-positive ASCC is more immunogenic with a higher density of tumor infiltrating lymphocytes that correlate with better response to CRT and more favorable prognosis compared to HPV-negative tumors. Immunotherapies including immune checkpoint inhibitors have brought new hope and promising results were recently demonstrated in metastatic ASCC. The addition of immunotherapies to CRT for localized disease is tested in early phase trials, and these results could have a profound impact on the way we treat ASCC in near future. Further research and novel approaches are expected to enhance our understanding of tumor biology and immunology, and improve patient stratification and treatment adaptation in the context of personalized medicine.

Treatment of squamous cell carcinoma of the anal canal: A new strategies with anti-EGFR therapy and immunotherapy

The incidence of squamous cell carcinoma of the anal canal (SCAC) is increasing in both sexes but the standard treatment remains that of 20 years ago. However, interesting data have recently emerged on the use of anti-epidermal growth factor receptor (EGFR) agents and immunotherapy in advanced disease. Thus, new avenues of research are opening up that will hopefully lead to more effective therapeutic strategies. We provide an overview of the latest studies published on this tumor and discuss the possible future therapeutic options for combination therapy, anti-EGFR treatment and radiotherapy.

Treatment outcomes of patients with localized anal squamous cell carcinoma according to HIV infection: systematic review and meta-analysis

Background

Definitive chemoradiation (CRT) is the standard treatment for localized squamous cell carcinoma of the anus (SCCA). Because most phase III trials in SCCA have excluded patients with HIV, the evidence on treatment outcomes of these patients is lacking. We performed a systematic review and meta-analysis on the efficacy and toxicity profiles of HIV-positive SCCA patients treated with definitive CRT.

Methods

The systematic search was conducted Embase, Medline, Cochrane Libary, Scopus, Lilacs and Opengrey, from inception until September 2017. Eligible studies were clinical trials, prospective or retrospective cohort studies. The main outcome variables were 3-year disease-free survival (DFS) and overall survival (OS) rates and frequency of grade 3 or 4 (G3/4) treatment-related toxicities, according to HIV status. Meta-analyses using pooled risk ratios were performed for binary outcomes from comparative studies from the antiretroviral therapy (HAART) era with the fixed effects model.

Results

Out of 3,951 studies, 40 were deemed eligible, with a total of 3,720 patients. One third (N=1,298; 34%) were HIV-positive and their median pre CRT CD4 count was 347 µm/L. HIV-positive patients presented higher risk of G3/4 cutaneous toxicities [risk ratio (RR) =1.34; 95% CI, 1.10-1.64; P=0.004; I²=77.7%], worse 3-year DFS rate (RR =1.32; 95% CI, 1.01-1.74; P=0.043; I²=52.19%), and 3-year OS rate (RR =1.77; 95% CI, 1.35-2.32; P<0.001; I²=6%).

Conclusions

Patients with localized SCCA and HIV infection treated with CRT tend to experience higher risk of toxicities and worse DFS and OS rates. Our findings suggest that future trials should be tailored to HIV-positive patients.

Cancer vaccine: learning lessons from immune checkpoint inhibitors

Cancer vaccines have been exclusively studied all through the past decades, and have made exceptional achievements in cancer treatment. Few cancer vaccines have been approved by the US Food and Drug Administration (FDA), for instance, Provenge, which was approved for the treatment of prostate carcinoma in 2012. Moreover, more recently, T-VEC got approval for the treatment of melanoma. While, the overall therapeutic effects of cancer vaccines have been taken into consideration as below expectations, low antigenicity of targeting antigen and tumor heterogeneity are the two key limiting barriers encountered by the cancer vaccines. Nonetheless, recent developments in cancer immune-therapies together with associated technologies, for instance the unparalleled achievements bagged by immune checkpoint inhibitor based therapies and neo-antigen identification tools, envisage potential improvements in cancer vaccines in respect to the treatments of malignancies. This review brings forth measures for the purpose of refining therapeutic cancer vaccines by learning lessons from the success of PD-1 inhibitor based immune-therapies.

Programmed death-ligand 1 expression correlates with diminished CD8+ T cell infiltration and predicts poor prognosis in anal squamous cell carcinoma patients

Objective

Increased expression of programmed death-ligand 1 (PD-L1) on tumor cells can be found in various malignancies; however, very limited information is known about its role in anal squamous cell carcinoma (ASCC). This study explored PD-L1 expression in ASCC patients and its association with patients' clinicopathological features, CD8+ T cell infiltration, and prognosis.

Methods

Formalin-fixed paraffin-embedded tumor samples from 26 patients with ASCC were retrieved. The levels of PD-L1 expression on the membrane of both tumor cells and tumor-infiltrating mononuclear cells (TIMCs) were evaluated by immunohistochemistry. CD8+ T cell densities, both within tumors and at the tumor-stromal interface, were also analyzed. Baseline clinicopathological characteristics, human papilloma virus (HPV) status, and outcome data correlated with PD-L1-positive staining.

Results

PD-L1 expression on tumor cells and TIMCs was observed in 46% and 50% of patients, respectively. Nineteen patients (73%) were HPV positive, with 7 showing PD-L1-positive staining on tumor cells and 9 showing PD-L1-positive staining on TIMCs. Increasing CD8+ density within tumors, but not immune stroma, was significantly associated with decreased PD-L1 expression by both tumor cells and TIMCs (P=0.0043 and P=0.0007). Patients with negative PD-L1 expression had significantly better progression-free survival (P=0.038 and P=0.0443) and a non-statistically significant trend toward longer overall survival (P=0.0882 and P=0.1222) compared with patients with positive PD-L1 expression.

Conclusion

PD-L1 is widely expressed on the membrane of tumor cells and TIMCs in ASCCs. Its negative impact on prognosis may be due to the diminished CD8+ T cell infiltration within tumors.

Exome sequencing reveals aberrant signalling pathways as hallmark of treatment-naive anal squamous cell carcinoma

Anal squamous cell carcinomas (ASCC) are rare tumours in humans. The etiological role of HPV infection is now well established but little is known about the molecular landscape and signalling pathways involved in the pathogenesis of this cancer. Here we report the results from a whole exome sequencing of a homogeneous group of 20 treatment-naive ASCC. A total of 2422 somatic single nucleotide variations (SNV) were found, with an overall moderate rate of somatic mutations per tumour (median: 105 relevant SNV per tumour) but a high mutational load in 3 tumours. The mutational signatures associated with age and APOBEC were observed in 100% and 60% of tumours respectively. The most frequently mutated genes were PIK3CA (25%) followed by FBXW7 (15%), FAT1 (15%), and TRIP12 (15%), the two last ones having never been described in ASCC. The main copy number alterations were gains of chromosome 3q (affecting PIK3CA) and losses of chromosome 11q (affecting ATM). The combined analysis of somatic mutations and copy number alterations show that recurrent alterations of the PI3K/AKT/mTOR pathway are frequent (60%) in these tumours, as well as potentially targetable alterations of other signalling pathways that have never been described in ASCC such as chromatin remodelling (45%) and ubiquitin mediated proteolysis (35%). These results highlight the possible implication of these aberrant signalling pathways in anal carcinogenesis and suggest promising new therapeutic approaches in ASCC. The high somatic mutation burden found in some tumours, suggesting an elevated neoantigen load could also predict sensitivity of ASCC to immunotherapy.

Radiation generates an abscopal response and complete resolution of metastatic squamous cell carcinoma of the anal canal: a case report

The abscopal effect is a rare phenomenon in the setting of radiation therapy (RT) for metastatic cancer where tumor regression occurs distant from the site of treatment. A proposed mechanism of the abscopal effect is the activation of a systemic antitumor immune response by localized RT. We report the first case, to our knowledge, of the abscopal effect in squamous carcinoma of the anal canal with metastases to pelvic lymph nodes, liver and bone. After palliative RT to the pelvis with sensitizing chemotherapy, complete response was observed not only in the primary tumor but also in bone and multiple liver metastases at 4 months after treatment, an effect that remained durable at 4-year follow-up. Understanding of the abscopal effect and the immune mechanisms associated with anal cancer may lead to new avenues of research to improve outcome for patients with this rare disease.

Immune Checkpoint Inhibitors in Melanoma and HIV Infection

Introduction:

Immunotherapy with immune checkpoint inhibitors increases the overall survival of patients with metastatic melanoma regardless of their oncogene addicted mutations. However, no data is available from clinical trials of effective therapies in subgroups of melanoma patients that carry chronic infective diseases such as HIV. Evidences suggest a key role of the immune checkpoint molecules as a mechanism of immune escape not only from melanoma but also from HIV host immune response.

Conclusion:

In this article, firstly, we will describe the role of the immune checkpoint molecules in HIV chronic infection. Secondly, we will summarize the most relevant clinical evidences utilizing immune checkpoint inhibitors for the treatment of melanoma patients. Lastly, we will discuss the potential implications as well as the potential applications of immune checkpoint molecule-based immunotherapy in patients with melanoma and HIV infection.

Pulmonary pleomorphic carcinoma with few PD-1-positive immune cells and regulatory T cells that showed a complete response to nivolumab

Pulmonary pleomorphic carcinoma has been shown to respond remarkably to PD‐1 inhibitors; however, the biomarkers for this therapy have not been fully proven. We report a case of pulmonary pleomorphic carcinoma with overexpressed PD‐L1, in which a complete response to nivolumab was sustained for >14 months. Immunohistochemical analysis revealed few PD‐1⁺ immune cells and regulatory T cells in the tumor, in addition to predominant infiltration of CD8⁺ cells and macrophages. Our findings suggest that the presence of a small number of PD‐1⁺ immune cells and regulatory T cells should be investigated as candidate therapeutic biomarkers.

Immune-Related Adverse Events Associated with Anti-PD-1/PD-L1 Treatment for Malignancies: A Meta-Analysis

Background: Treatment of cancers with programmed cell death protein 1 (PD-1) pathway inhibitors can lead to immune-related adverse events (irAEs), which could be serious and even fetal. Therefore, clinicians should be aware of the characteristics of irAEs associated with the use of such drugs. Methods: The MEDLINE, EMBASE, and Cochrane databases were searched to find potential studies using the following strategies: anti-PD-1/PD-L1 treatment; irAEs; and cancer. R© package Meta was used to pool incidence. Results: Forty-six studies representing 12,808 oncologic patients treated with anti-PD-1/PD-L1 agents were included in the meta-analysis. The anti-PD-1/PD-L1 agents included nivolumab, pembrolizumab, atezolizumab, durvalumab, avelumab, and BMS-936559. The tumor types were melanomas, Hodgkin lymphomas, urothelial carcinomas, breast cancers, non-small cell lung cancers, renal cell carcinomas (RCC), colorectal cancers, and others. We described irAEs according to organ systems, namely, the skin (pruritus, rash, maculopapular rash, vitiligo, and dermatitis), endocrine system (hypothyroidism, hyperthyroidism, hypophysitis, thyroiditis, and adrenal insufficiency), digestive system (colitis, diarrhea, pancreatitis, and increased AST/ALT/bilirubin), respiratory system (pneumonitis, lung infiltration, and interstitial lung disease), and urinary system (increased creatinine, nephritis, and renal failure). In patients treated with the PD-1 signaling inhibitors, the overall incidence of irAEs was 26.82% (95% CI, 21.73-32.61; I², 92.80) in any grade and 6.10% (95% CI, 4.85-7.64; I², 52.00) in severe grade, respectively. The development of irAEs was unrelated to the dose of anti-PD-1/PD-L1 agents. The incidence of particular irAEs varied when different cancers were treated with different drugs. The incidence of death due to irAEs was around 0.17%. Conclusion: The occurrence of irAEs was organ-specific and related to drug and tumor types.

Telomere Dynamics in Immune Senescence and Exhaustion Triggered by Chronic Viral Infection

The progressive loss of immunological memory during aging correlates with a reduced proliferative capacity and shortened telomeres of T cells. Growing evidence suggests that this phenotype is recapitulated during chronic viral infection. The antigenic volume imposed by persistent and latent viruses exposes the immune system to unique challenges that lead to host T-cell exhaustion, characterized by impaired T-cell functions. These dysfunctional memory T cells lack telomerase, the protein capable of extending and stabilizing chromosome ends, imposing constraints on telomere dynamics. A deleterious consequence of this excessive telomere shortening is the premature induction of replicative senescence of viral-specific CD8+ memory T cells. While senescent cells are unable to expand, they can survive for extended periods of time and are more resistant to apoptotic signals. This review takes a closer look at T-cell exhaustion in chronic viruses known to cause human disease: Epstein–Barr virus (EBV), Hepatitis B/C/D virus (HBV/HCV/HDV), human herpesvirus 8 (HHV-8), human immunodeficiency virus (HIV), human T-cell leukemia virus type I (HTLV-I), human papillomavirus (HPV), herpes simplex virus-1/2 (HSV-1/2), and Varicella–Zoster virus (VZV). Current literature linking T-cell exhaustion with critical telomere lengths and immune senescence are discussed. The concept that enduring antigen stimulation leads to T-cell exhaustion that favors telomere attrition and a cell fate marked by enhanced T-cell senescence appears to be a common endpoint to chronic viral infections.

Effect of CD4 Count on Treatment Toxicity and Tumor Recurrence in Human Immunodeficiency Virus-Positive Patients With Anal Cancer

PURPOSE

To study the effects of immunosuppression on treatment toxicity, long-term cancer recurrence risk, and survival among human immunodeficiency virus (HIV)-positive anal cancer patients.

METHODS AND MATERIALS

From a nationwide retrospective cohort of veterans with anal cancer we identified 142 HIV-positive patients with stage I-III disease, diagnosed between 2000 and 2015 and treated with definitive-intent chemotherapy and radiation. We used regression models to study the impact of pretreatment CD4 counts and longitudinal posttreatment CD4 counts on outcomes including acute toxicity, long-term ostomy rates, cancer recurrence, cancer-specific survival, and overall survival. All models were adjusted for potential confounders.

RESULTS

The median pretreatment CD4 count was 375 cells/mm³, which dropped to 157 cells/mm³ after treatment. Each 100-cell/mm³ decrease in pretreatment CD4 count was associated with an increased risk of acute hematologic toxicity (odds ratio 1.19, 95% confidence interval [CI] 1.01-1.42, P=.04) and hospitalization for hematologic toxicity (odds ratio 1.24, 95% CI 1.00-1.54, P=.049) but not gastrointestinal toxicity, tumor recurrence, or cancer-specific mortality (P>.05). Each 100-cells/mm³ decrease in posttreatment CD4 count increased the risk of recurrence by 54% (hazard ratio 1.54, 95% CI 1.09-2.17, P=.01) and cancer mortality by 46% at a trend level (hazard ratio 1.46, 95% CI 0.99-2.14, P=.06). Neither pre- nor posttreatment CD4 count influenced long-term ostomy rates or overall survival (all P>.05).

CONCLUSIONS

Lower pretreatment CD4 counts were associated with acute hematologic toxicity, and lower posttreatment CD4 count levels were associated with an increased risk of tumor recurrence. These results suggest that immune surveillance may play an important role in long-term disease control in anal cancer.

Trial watch: Immune checkpoint blockers for cancer therapy

Immune checkpoint blockers (ICBs) are literally revolutionizing the clinical management of an ever more diversified panel of oncological indications. Although considerable attention persists around the inhibition of cytotoxic T lymphocyte-associated protein 4 (CTLA4) and programmed cell death 1 (PDCD1, best known as PD-1) signaling, several other co-inhibitory T-cell receptors are being evaluated as potential targets for the development of novel ICBs. Moreover, substantial efforts are being devoted to the identification of biomarkers that reliably predict the likelihood of each patient to obtain clinical benefits from ICBs in the absence of severe toxicity. Tailoring the delivery of specific ICBs or combinations thereof to selected patient populations in the context of precision medicine programs constitutes indeed a major objective of the future of ICB-based immunotherapy. Here, we discuss recent preclinical and clinical advances on the development of ICBs for oncological indications.

Clinical utility of circulating cell-free DNA in advanced colorectal cancer

BACKGROUND

Circulating cell-free DNA (cfDNA) isolated from the plasma of cancer patients (pts) has been shown to reflect the genomic mutation profile of the tumor. However, physician and patient assessment of clinical utility of these assays in patients with metastatic colorectal cancer (mCRC) has not been previously described.

METHODS

Patients were prospectively consented to a prospective genomic matching protocol (Assessment of Targeted Therapies Against Colorectal Cancer [ATTACC]), with collection of blood for cfDNA extraction and sequencing of a 54-gene panel in a CLIA-certified lab. Formalin-fixed, paraffin-embedded (FFPE) tissue from prior resections or biopsies underwent 50-gene sequencing. Results from both assays were returned to the treating physicians for patient care and clinical trial selection. Follow-up surveys of treating physicians and chart reviews assessed clinical utility.

RESULTS

128 mCRC pts were enrolled between 6/2014 and 1/2015. Results were returned in median of 13 and 26 days for cfDNA and FFPE sequencing, respectively. With cfDNA sequencing, 78% (100/128) of samples had a detectable somatic genomic alteration. 50% of cfDNA cases had potentially actionable alterations, and 60% of these could be genomically matched to at least one clinical trial in our institution. 50% (15/30) of these pts enrolled onto an identified matched trial. Physicians reported that the cfDNA testing improved the quality of care they could provide in 73% of the cases, and that 89% of pts reported greater satisfaction with the efforts to personalize experimental therapeutic agents.

CONCLUSIONS

cfDNA sequencing can provide timely information on potentially actionable mutations and amplifications, thereby facilitating clinical trial enrollment and improving the perceived quality of care.

Comprehensive Genomic Profiling of Metastatic Squamous Cell Carcinoma of the Anal Canal

Squamous cell carcinoma of the anal canal (SCCA) is a rare gastrointestinal malignancy with an increasing annual incidence globally. The majority of cases are linked to prior infection with the human papillomavirus (HPV). For patients with metastatic SCCA, no consensus standard treatment exists. Identification of relevant targeted agents as novel therapeutic approaches for metastatic SCCA has been limited by a lack of comprehensive molecular profiling. We performed whole-exome sequencing on tumor-normal pairs from 24 patients with metastatic SCCA. Tumor tissue from 17 additional patients was analyzed using a 263-gene panel as a validation cohort. Gene expression profiling was performed on available frozen tissue to assess for differential expression patterns. Based on these findings, patient-derived xenograft (PDX) models of SCCA were generated to test targeted therapies against PI3K and EGFR. Despite a low mutation burden, mutations in PIK3CA, MLL2, and MLL3 were among the most commonly mutated genes. An association between TP53 mutations and HPV-negative SCCA tumors was observed. Gene expression analysis suggested distinct tumor subpopulations harboring PIK3CA mutations and for which HPV had integrated into the host genome. In vivo studies demonstrated improvement with anti-EGFR treatment. Gene mutation frequencies, tumor mutation burden, and gene expression patterns for metastatic SCCA appear similar to other HPV-associated malignancies.Implications: This first comprehensive genomic characterization for patients with metastatic SCCA provides further rationale for the integration of SCCA into the development of novel targeted therapies across HPV-related cancers. Mol Cancer Res; 15(11); 1542-50. ©2017 AACR.

PD-1/PD-L blockade in gastrointestinal cancers: lessons learned and the road toward precision immunotherapy

Gastrointestinal (GI) malignancies are the most prevalent tumors worldwide, with increasing incidence and mortality. Although surgical resection, chemotherapy, radiotherapy, and molecular targeted therapy have led to significant advances in the treatment of GI cancer patients, overall survival is still low. Therefore, alternative strategies must be identified to improve patient outcomes. In the tumor microenvironment, tumor cells can escape the host immune response through the interaction of PD-1 and PD-L, which inhibits the function of T cells and tumor-infiltrating lymphocytes while increasing the function of immunosuppressive T regulatory cells. The use of an anti-PD-1/PD-L blockade enables reprogramming of the immune system to efficiently identify and kill tumor cells. In recent years, the efficacy of PD-1/PD-L blockade has been demonstrated in many tumors, and this treatment is expected to be a pan-immunotherapy for tumors. Here, we review the signaling pathway underlying the dysregulation of PD-1/PD-L in tumors, summarize the current clinical data for PD-1/PD-L inhibitors in GI malignancies, and discuss road toward precision immunotherapy in relation to PD-1/PD-L blockade. The preliminary data for PD-1/PD-L inhibitors are encouraging, and the precision immunotherapy of PD-1/PD-L inhibitors will be a viable and pivotal clinical strategy for GI cancer therapy.