PD-1 blockade with nivolumab in endemic Kaposi sarcoma

Endemic Kaposi's Sarcoma

Kaposi's sarcoma (KS) is a common neoplasm in Eastern and central Africa reflecting the spread of human gammaherpesvirus-8 (HHV-8), now considered a necessary causal agent for the development of KS. The endemic KS subtype can follow an aggressive clinical course with ulcerative skin lesions with soft tissue invasion or even bone or visceral involvement. In the latter cases, a thorough imaging work-up and better follow-up schedules are warranted. As KS is a chronic disease, the therapeutic goal is to obtain sustainable remission in cutaneous and visceral lesions and a good quality of life. Watchful monitoring may be sufficient in localized cutaneous forms. Potential therapeutic modalities for symptomatic advanced KS include systemic chemotherapies, immunomodulators, immune checkpoint inhibitors, and antiangiogenic drugs.

Targeted therapies and checkpoint inhibitors in sarcoma

Sarcomas are defined as a group of mesenchymal malignancies with over 100 heterogeneous subtypes. As a rare and difficult to diagnose entity, micrometastasis is already present at the time of diagnosis in many cases. Current treatment practice of sarcomas consists mainly of surgery, (neo)adjuvant chemo- and/or radiotherapy. Although the past decade has shown that particular genetic abnormalities can promote the development of sarcomas, such as translocations, gain-of-function mutations, amplifications or tumor suppressor gene losses, these insights have not led to established alternative treatment strategies so far. Novel therapeutic concepts with immunotherapy at its forefront have experienced some remarkable success in different solid tumors while their impact in sarcoma remains limited. In this review, the most common immunotherapy strategies in sarcomas, such as immune checkpoint inhibitors, targeted therapy and cytokine therapy are concisely discussed. The programmed cell death (PD)-1/PD-1L axis and apoptosis-inducing cytokines, such as TNF-related apoptosis-inducing ligand (TRAIL), have not yielded the same success like in other solid tumors. However, in certain sarcoma subtypes, e.g. liposarcoma or undifferentiated pleomorphic sarcoma, encouraging results in some cases when employing immune checkpoint inhibitors in combination with other treatment options were found. Moreover, newer strategies such as the targeted therapy against the ancient cytokine macrophage migration inhibitory factor (MIF) may represent an interesting approach worth investigation in the future.

Immunotherapy for KSHV-associated diseases

Kaposi sarcoma herpesvirus (KSHV)-associated diseases (Kaposi sarcoma, multicentric Castleman disease, primary effusion lymphoma, and KSHV inflammatory cytokine syndrome) are associated with immune suppression and dysregulation and loss of KSHV-specific immunity. These diseases are most frequent in people living with HIV as well as those with primary or iatrogenic immune deficiencies. KSHV itself can modulate the immune system via viral homologs of host cytokines or downregulation of immune-surface markers altering host immune surveillance. These factors make KSHV-associated diseases prime targets for immunotherapy approaches. Several agents have been studied or are under investigation in KSHV-associated diseases, including monoclonal antibodies, immunomodulatory agents, and therapeutic cytokines. Here, we review the role of immunotherapies in KSHV-associated diseases.

Management of Vascular Sarcoma

Vascular sarcomas encompass 3 well-defined sarcoma types: hemangioendothelioma, Kaposi sarcoma, and angiosarcoma. These distinct types are exceedingly rare and very different in terms of clinical behavior, biological features, and treatment approach. Because of this rarity and heterogeneity, it is crucial that vascular sarcomas are treated in sarcoma reference centers or networks, in order to ensure optimal management. The diversity of vascular sarcomas also needs to be taken into account in the design of clinical trials, in order to produce meaningful results that can be consistently translated into everyday clinical practice.

Yield of FDG PET/CT for Defining the Extent of Disease in Patients with Kaposi Sarcoma

Simple Summary

The potential role of positron emission tomography/computed tomography with fluorodeoxyglucose (FDG PET/CT) for assessing the extent of Kaposi sarcoma is not well studied. We analyzed FDG PET/CTs performed on 75 patients referred to our department for Kaposi sarcoma staging or restaging. FDG PET/CTs detected most lymph nodes, bone, and muscle lesions, whereas digestive and mucous lesions could be missed. Most cutaneous lesions can be identified when whole-body FDG PET/CT (including lower limbs) is performed. Thus, a true whole-body FDG PET/CT can be recommended for staging purposes in patients with active Kaposi sarcoma and, if positive, be useful for therapeutic evaluation and follow-up.

Abstract

Background: Positron emission tomography/computed tomography with fluorodeoxyglucose (F-18) (FDG PET/CT) is increasingly used in Kaposi sarcoma (KS), but its value has not been assessed. Objectives: In this study, we aimed to evaluate the diagnostic accuracy of FDG PET/CT to define the extent of disease in KS. Methods: Consecutive patients with KS referred to our department for FDG PET/CT were included. The diagnostic accuracy of FDG PET/CT for cutaneous and extra-cutaneous KS staging was assessed on a per lesion basis compared to staging obtained from clinical examination, standard imaging, endoscopy, histological analyses, and follow-up. Results: From 2007 to 2017, 75 patients with FDG PET/CT were analyzed. The sensitivity and specificity of FDG PET/CT for the overall detection of KS lesions were 71 and 98%, respectively. Sensitivity and specificity were 100 and 85% for lymph nodes, 87 and 98% for bone, 87 and 100% for lungs, and 100 and 100% for muscle involvement, whereas sensitivity was only 17% to detect KS digestive involvement. The sensitivity of the diagnostic for KS cutaneous involvement increased from 73 to 88% when using a whole-body examination. Conclusion: FDG PET/CT showed good sensitivity and specificity for KS staging (digestive involvement excepted) and could be used for staging patients with active KS.

Impact of Anti PD-1 Immunotherapy on HIV Reservoir and Anti-Viral Immune Responses in People Living with HIV and Cancer

The role of immune checkpoints (ICPs) in both anti-HIV T cell exhaustion and HIV reservoir persistence, has suggested that an HIV cure therapeutic strategy could involve ICP blockade. We studied the impact of anti-PD-1 therapy on HIV reservoirs and anti-viral immune responses in people living with HIV and treated for cancer. At several timepoints, we monitored CD4 cell counts, plasma HIV-RNA, cell associated (CA) HIV-DNA, EBV, CMV, HBV, HCV, and HHV-8 viral loads, activation markers, ICP expression and virus-specific T cells. Thirty-two patients were included, with median follow-up of 5 months. The CA HIV-DNA tended to decrease before cycle 2 (p = 0.049). Six patients exhibited a ≥0.5 log₁₀ HIV-DNA decrease at least once. Among those, HIV-DNA became undetectable for 10 months in one patient. Overall, no significant increase in HIV-specific immunity was observed. In contrast, we detected an early increase in CTLA-4 + CD4+ T cells in all patients (p = 0.004) and a greater increase in CTLA-4+ and TIM-3 + CD8+ T cells in patients without HIV-DNA reduction compared to the others (p ≤ 0.03). Our results suggest that ICP replacement compensatory mechanisms might limit the impact of anti-PD-1 monotherapy on HIV reservoirs, and pave the way for combination ICP blockade in HIV cure strategies.

Therapeutic Perspectives in the Systemic Treatment of Kaposi’s Sarcoma

Simple Summary

Alternative systemic treatments are needed for patients who develop chemotherapy-refractory KS. Anti-angiogenic therapies constitute interesting therapeutic targets in this context, due to the central role of angiogenesis in KS pathogenesis, and could represent attractive alternatives. Immune checkpoints blockade could also be an interesting therapeutic approach in order to restore anti-HHV-8 immunity and tumor control.

Abstract

In patients with Kaposi’s sarcoma (KS), the therapeutic goal is to achieve a durable remission in the size and number of skin and visceral lesions. Although most patients show tumor regression in response to standard systemic chemotherapy regimens, alternative systemic treatments are needed for patients who develop refractory KS. Anti-angiogenic therapies represent attractive therapeutic targets in this context, due to the central role of angiogenesis in KS pathogenesis. Pomalidomide, which exhibits such anti-angiogenic activity through inhibition of VEGF, currently constitutes the most promising agent of this class and has been recently approved by the FDA. In addition, immune checkpoint blockade also represents an interesting alternative therapeutic approach through the restoration of immunity against HHV-8, the causative agent of KS, and improvement of tumor control. Although small series of cases treated successfully with these drugs have been reported, there is no marketing approval for anti-immune checkpoint antibodies for KS to date. In the present review, we will discuss potential therapeutic options for patients with recurrent or refractory KS, including systemic chemotherapies, immune checkpoint inhibitors, anti-herpesvirus agents, and anti-angiogenic drugs. Well-conducted clinical trials in this population are urgently needed to correctly address the efficacy of targeted agents and immunomodulators, while monitoring for adverse effects.

Current and Future Tools for Diagnosis of Kaposi's Sarcoma

Simple Summary

Kaposi’s sarcoma, a rare opportunistic tumor, is observed in four epidemiological conditions (AIDS-related, iatrogenic, endemic or classic KS). Although in most cases KS is an indolent disease, it can be locally aggressive and/or it can invade other organs than the skin, resulting in more severe presentations, especially in patients with severe immunosuppression. There is no consensus on the imaging workup that is necessary for either the initial staging of the disease or the follow-up. Future perspectives include the use of certain non-invasive imaging tools that may help to evaluate the clinical response to treatment, as well as certain new histological markers that may help in guiding the treatment planning for this atypical neoplasm.

Abstract

Kaposi’s sarcoma (KS) is a rare, atypical malignancy associated with immunosuppression and can be qualified as an opportunistic tumor, which responds to immune modulation or restoration. Four different epidemiological forms have been individualized (AIDS-related, iatrogenic, endemic or classic KS). Although clinical examination is sufficient to diagnose cutaneous lesions of KS, additional explorations are necessary in order to detect lesions involving other organs. New histological markers have been developed in recent years concerning the detection of HHV-8 latent or lytic proteins in the lesions, helping to confirm the diagnosis when it is clinically doubtful. More recently, the evaluation of the local immune response has also been shown to provide some guidance in choosing the appropriate therapeutic option when necessary. We also review the indication and the results of conventional radiological imaging and of non-invasive imaging tools such as ¹⁸F-fluoro-deoxy-glucose positron emission tomography, thermography and laser Doppler imaging for the diagnosis of KS and for the follow-up of therapeutic response in patients requiring systemic treatment.

Expression of Programmed Cell Death Proteins in Kaposi Sarcoma and Cutaneous Angiosarcoma

Not only for cutaneous angiosarcoma (CAS) patients but also for advanced and therapy-refractory patients with classic Kaposi sarcoma (CKS) and human immunodeficiency virus (HIV)-associated Kaposi sarcoma (HIV-KS) there is a high need for more effective treatment modalities. The aim of this work was to study programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) protein expression and related immune parameters in CKS, HIV-KS, and CAS and correlate it with other immunologic parameters and clinical data. Immunohistochemistry was performed on formalin-fixed paraffin-embedded tumor tissue of 19 CKS, 7 HIV-KS, and 12 CAS patients using antibodies against the following (and they are): PD-1, PD-L1, CD4, CD8, CD56, and FOXP3. PD-1 expression significantly correlated with PD-L1 expression Moreover, PD-1 and PD-L1 expression significantly correlated with CD56 and FOXP3 expression. High intratumoral FOXP3 expression was significantly associated with disease relapse (P=0.029). CD4 and FOXP3 expression was significantly higher in CKS and CAS, as compared with HIV-KS. All in all, PD-1 and PD-L1 expression was relatively weak and did not significantly differ between CKS, HIV-KS, and CAS patients. Nevertheless, PD-1 was positive in 31.6% of CKS, 28.6% of HIV-KS, and 33.3% of CAS patients. PD-L1 was expressed in 36.6% of CKS, 28.6% of HIV-KS, and 41.7% of CAS patients. We have provided evidence that PD-1/PD-L1 signalling is of importance in angiosarcomas such as CKS, HIV-KS, and CAS. Our results support the notion that the use of PD-1/PD-L1 inhibitors may represent an effective strategy against these tumors.

Systemic Treatment Initiation in Classical and Endemic Kaposi's Sarcoma: Risk Factors and Global Multi-State Modelling in a Monocentric Cohort Study

Simple Summary

Over the past decades, clinical features and patients’ outcome of iatrogenic and HIV-related KS epidemiological subtypes have been widely described in large cohort series. Due to their lower incidence and the limited resources available in endemic KS countries, classical and endemic KS epidemiological studies remain scarce, thus increasing the challenge of such clinically heterogeneous chronic diseases’ management. In this large retrospective cohort study, six risk factors for treatment initiation were identified: time between first symptoms and diagnosis ≥1 year, endemic KS, total number of lesions ≥10, visceral or head/neck localization and edema. No response or treatment-free time difference was observed between the most frequently used therapeutic options: chemotherapy and interferon-alpha. Assessment for systemic treatment risk factors provides guidance for adequate follow-up and patients’ information on disease outcome. Absence of efficacy difference between systemic regimens allows treatment choice based on fitness.

Abstract

Background: Although several studies described the clinical course of epidemic and post-transplant Kaposi’s Sarcoma (KS), the lack of large cohorts of classic/endemic KS, precluded such characterization. Methods: We used multi-state modelling in a retrospective monocentric study to evaluate global disease evolution and identify risk factors for systemic treatment (ST) initiation. 160 classic/endemic KS patients consecutively diagnosed between 1990 and 2013 were included. Results: 41.2% of classic/endemic KS patients required ST. Cumulative incidence of ST after 2 years of follow-up was 28.4% [95% CI: 20.5; 35.5]. Multivariate analysis identified six risk factors for ST initiation: time between first symptoms and diagnosis ≥1 year, endemic KS, total number of lesions ≥10, visceral, head or neck localization and presence of edema. Type of ST, type of KS, age and time between diagnosis and ST were not associated with response. Mean treatment-free time during the first 5 years following ST was 44 months for interferon and 44.6 months for chemotherapy treated patients (Mean difference: −0.5 months [95% CI: −9.5; 4.9]). Conclusions: Our study reveals ST risk factors in classic/endemic KS and highlights the clinical aggressiveness of the endemic KS subtype. No efficacy difference was observed between standard of care treatments, enabling treatment choice based on patient’s fitness.

Immunotherapy and Gene Therapy for Oncoviruses Infections: A Review

Immunotherapy has been shown to be highly effective in some types of cancer caused by viruses. Gene therapy involves insertion or modification of a therapeutic gene, to correct for inappropriate gene products that cause/may cause diseases. Both these types of therapy have been used as alternative ways to avoid cancers caused by oncoviruses. In this review, we summarize recent studies on immunotherapy and gene therapy including the topics of oncolytic immunotherapy, immune checkpoint inhibitors, gene replacement, antisense oligonucleotides, RNA interference, clustered regularly interspaced short palindromic repeats Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based gene editing, transcription activator-like effector nucleases (TALENs) and custom treatment for Epstein-Barr virus, human T-lymphotropic virus 1, hepatitis B virus, human papillomavirus, hepatitis C virus, herpesvirus associated with Kaposi's sarcoma, Merkel cell polyomavirus, and cytomegalovirus.

Histopathologic PD-L1 Tumor Expression and Prognostic Significance in Nonmelanoma Skin Cancers: A Systematic Review

ABSTRACT

PD-L1 and PD-1 inhibitors are being increasingly used to treat a variety of nonmelanoma skin cancers (NMSCs). This systematic review summarizes PD-L1 expression in NMSCs and determines its use for prognosis using targeted immunotherapy. A primary search of peer-reviewed English-language medical literature was conducted for studies on PD-L1 tumor expression in biopsied or excised NMSCs. Fifty-nine articles met criteria for inclusion. PD-L1 expression in advanced NMSCs ranged from 22%-89% for basal cell carcinomas, 42%-50% for Merkel cell carcinomas, and 26%-100% for squamous cell carcinomas. Study limitations included clone heterogeneity across studies, complicating comparison of PD-L1 expression. Differences were also noted in the selection of tumor reactivity threshold. We conclude that there is insufficient evidence to determine the prognostic significance of PD-L1 expression in NMSCs as a whole, but this remains a promising area. More investigation into the role of tumor PD-L1 as a biomarker for predicting clinical response to PD-L1 and PD-1 inhibitors in NMSCs is needed.

Is immunotherapy in the future of therapeutic management of sarcomas?

Sarcomas are rare, ubiquitous and heterogeneous tumors usually treated with surgery, chemotherapy, target therapy, and radiotherapy. However, 25-50% of patients experience local relapses and/or distant metastases after chemotherapy with an overall survival about 12-18 months. Recently, immuno-therapy has revolutionized the cancer treatments with initial indications for non-small cell lung cancer (NSCLC) and melanoma (immune-checkpoint inhibitors).Here, we provide a narrative review on the topic as well as a critical description of the currently available trials on immunotherapy treatments in patients with sarcoma. Given the promising results obtained with anti-PD-1 monoclonal antibodies (pembrolizumab and nivolumab) and CAR-T cells, we strongly believe that these new immunotherapeutic approaches, along with an innovative characterization of tumor genetics, will provide an exciting opportunity to ameliorate the therapeutic management of sarcomas.

Clinicopathologic Correlation of Kaposi Sarcoma Involving the Ocular Adnexa: Immunophenotyping of Diagnostic and Therapeutic Targets

PURPOSE

To describe the clinicopathologic characteristics and the expression of diagnostic/treatment targets in ocular adnexal Kaposi Sarcoma.

METHODS

We conducted a clinical-pathologic retrospective case series. Immunohistochemical staining for cluster of differentiation 31 (CD31), human herpesvirus-8 (HHV8), platelet-derived growth factor receptor alpha (PDGFR-A), vascular endothelial growth factor receptor-1 (VEGF), tyrosine-protein kinase Kit (c-Kit), and programmed cell death protein 1 (PD-1) were performed. Percentage of positive tumor cells was recorded for PD-1; staining intensity and distribution (H-score) were determined for the remaining stains. A Friedman non-parametric ANOVA analysis evaluated the staining.

RESULTS

The study cohort included 13 patients (age 25 to 95 years; mean 46): 7 lesions were in the eyelid, 5 in the conjunctiva, and 1 in the cornea. Nine of 11 lesions (82%) were in human immunodeficiency syndrome-positive patients (human immunodeficiency syndrome status was unknown in 2 cases). Staging included 6 plaques and 7 nodules. The mean H-scores of CD31, HHV8, c-Kit, VEGF, and PDGF-A were 8.00, 8.23, 2.77, 11.54, and 10.31, respectively. Mean PD-1 staining was 6.46%. The Friedman non-parametric ANOVA analysis showed VEGF, PDGF-A, CD31, and HHV8 differed significantly, and all differed significantly from c-Kit. Programmed cell death protein 1 staining was not significant with any clinical variable.

CONCLUSIONS

Cluster of differentiation 31 and HHV8 are helpful diagnostic adjuncts for ocular adnexal Kaposi Sarcoma. Platelet-derived growth factor receptor alpha and VEGF are promising treatment targets. Programmed cell death protein 1/PD-L1 and c-Kit are targets that are useful in several tumors; their roles in ocular adnexal Kaposi Sarcoma warrant further studies.

PD-1 and PD-L1 expression in Kaposi sarcoma: A comparative study according to the pathological stage and clinical characteristics

BACKGROUND

Kaposi sarcoma (KS) is a mesenchymal tumor with distinct histopathological features according to stage of progression. Programmed death-1 (PD-1) and its ligand PD-L1 play major roles in the immune escape strategy of tumors.

OBJECTIVES

This study evaluated expression of PD-1 and PD-L1 in various stages of KS and investigated associations between their expression and clinical characteristics.

METHODS

Fifty cases with histopathologically diagnosed KS were classified as early or late stage. These specimens were stained with anti-PD-1 and anti-PD-L1 antibodies. The extent of expression in the intratumoral and peritumoral areas was judged by two dermatopathologists.

RESULTS

PD-1 and PD-L1 were expressed in 72.2% (13/18) and 11.1% (2/18) of early-stage cases, respectively, compared with 43.8% (14/32) and 28.1% (9/32) of late-stage cases, respectively. At the late stage, PD-1 expression was significantly higher in the peritumoral area than in the intratumoral area (P = 0.001). PD-1 expression in the intratumoral area was significantly higher at the early stage than at the late stage (P = 0.013). PD-L1 expression in the peritumoral area was significantly higher at the late stage than at the early stage (P = 0.038).

CONCLUSIONS

The pattern of PD-1 and PD-L1 expression differs according to the stage of KS, but is unaffected by clinical variables.

Immune checkpoint inhibitors to treat cutaneous malignancies

As the incidence of cutaneous malignancies continues to rise and their treatment with immunotherapy expands, dermatologists and their patients are more likely to encounter immune checkpoint inhibitors. While the blockade of immune checkpoint target proteins (cytotoxic T-lymphocyte-associated protein-4, programmed cell death-1, and programmed cell death ligand-1) generates an antitumor response in a substantial fraction of patients, there is a critical need for reliable predictive biomarkers and approaches to address refractory disease. The first article of this Continuing Medical Education series reviews the indications, efficacy, safety profile, and evidence supporting checkpoint inhibition as therapeutics for metastatic melanoma, cutaneous squamous cell carcinoma, and Merkel cell carcinoma. Pivotal studies resulting in the approval of ipilimumab, pembrolizumab, nivolumab, cemiplimab, and avelumab by regulatory agencies for various cutaneous malignancies, as well as ongoing clinical research trials, are discussed.

PD-1 blockade for disseminated Kaposi sarcoma in a patient with atopic dermatitis and chronic CD8 lymphopenia

We describe a 53-year-old male patient with a history of long-standing atopic dermatitis (AD) who presented with disseminated Kaposi sarcoma (KS). Although he never had received long-term immunosuppressive treatment for his AD, he had a 16-year history of CD8 lymphopenia. Because of his heavily pretreated progressive KS in lymph nodes and soft tissues, we treated the patient using pembrolizumab 2 mg/kg body weight 3-weekly. On PET-computed tomography 3-months after the initiation of pembrolizumab therapy, a solid treatment response was detected in all tumor sites - 6-months later a mixed response was observed. Pembrolizumab therapy for further 10 months resulted in stable disease. Notably, his AD also improved during the pembrolizumab treatment period. This report highlights a rare association between AD and KS that was complicated by chronic CD8 lymphopenia of unknown origin. Even though our patient was immunocompromised, he showed an overall good response to pembrolizumab treatment.

Assessment of the Safety of Pembrolizumab in Patients With HIV and Advanced Cancer-A Phase 1 Study

Importance

Anti-PD-1 (anti-programmed cell death 1) and anti-PD-L1 (anti-programmed cell death ligand 1) regimens are preferred therapies for many cancers, including cancers associated with HIV. However, patients with HIV were excluded from most registered trials.

Objective

The primary objective was to evaluate the safety of pembrolizumab in people with HIV and advanced cancer; the secondary objective was to evaluate tumor responses.

Design, Setting, and Participants

Open-label, nonrandomized, phase 1 multicenter study conducted at 7 Cancer Immunotherapy Trials Network sites. Patients with HIV and advanced cancer as well as a CD4 count greater than or equal to 100 cells/μL, antiretroviral therapy (ART) for 4 or more weeks, and an HIV viral load of less than 200 copies/mL were eligible. Exclusion criteria included uncontrolled hepatitis B or C infection, active immunosuppressive therapy, or a history of autoimmune disease requiring systemic therapy.

Interventions

Pembrolizumab, 200 mg, administered intravenously every 3 weeks for up to 35 doses in 3 CD4 count-defined cohorts. Participants continued ART.

Main Outcomes and Measures

Safety and tolerability were assessed using current NCI Common Terminology Criteria for Adverse Events. Immune-related adverse events grade 2 or higher were considered immune-related events of clinical interest (irECI). Tumor responses were evaluated using standard tumor-specific criteria.

Results

Thirty participants (28 men and 2 women; median [range] age, 57 [39-77] years) were enrolled from April 2016 through March 2018; 6 had Kaposi sarcoma (KS), 5 had non-Hodgkin lymphoma (NHL), and 19 had non-AIDS-defining cancers. Safety was observed over 183 cycles of treatment with pembrolizumab. Most treatment-emergent adverse events at least possibly attributed to pembrolizumab were grade 1 or 2 (n = 22), and 20% (n = 6) were grade 3. The irECI included hypothyroidism (6 participants), pneumonitis (3 participants), rash (2 participants), an elevated aminotransferase/alanine aminotransferase level (1 participant), and a musculoskeletal event (1 participant). One participant with pretreatment KS herpesvirus (KSHV) viremia developed a polyclonal KSHV-associated B-cell lymphoproliferation and died. HIV was controlled in all participants. Increases in CD4 count were not statistically significant (median increase, 19 cells/μL; P = .18). Best tumor responses included complete response (lung, 1 patient), partial response (NHL, 2 patients), stable disease for 24 weeks or more (KS, 2 patients), stable disease for less than 24 weeks (15 patients), and progressive disease (8 patients); 2 patients were not evaluable.

Conclusions and Relevance

Pembrolizumab has acceptable safety in patients with cancer, HIV treated with ART, and a CD4+ T-cell count of greater than 100 cells/μL but may be associated with KSHV-associated B-cell lymphoproliferation. Clinical benefit was noted in lung cancer, NHL, and KS. Anti-PD-1 therapy is appropriate for US Food and Drug Administration-approved indications and clinical trials in this population.

Trial Registration

ClinicalTrials.gov identifier: NCT02595866.

Recent advances and application of PD-1 blockade in sarcoma

The role of the programmed death-1 (PD-1) signaling pathway in tumor immunotherapy is becoming increasingly important, and several PD-1-blocking agents have been approved by the US Food and Drug Administration. PD-1-blocking therapy alone or in combination with other therapeutic modalities has become a standard treatment for several kinds of solid tumors. However, sarcomas are not indications for anti-PD-1 therapy. Sarcomas are a group of heterogeneous diseases that can currently only be cured by surgery at the early stage. No effective treatments exist for sarcoma patients in advanced stages. Owning to the diversity of sarcomas, it is very difficult to conduct randomized controlled clinical studies on specific subtypes of sarcomas. Although clinical studies of sarcomas continue, few breakthroughs in the treatment of sarcomas have been achieved over the past decades. This review summarizes recent progress in anti-PD-1 therapy for sarcomas. Based on the published data, PD-1 blockade may be more effective in combination with other modalities for the treatment of sarcomas. In addition, biomarkers may be used to ascertain sensitivity to PD-1 blockade in sarcoma patients.

Kaposi Sarcoma Updates

Kaposi sarcoma (KS) is an angioproliferative mesenchymal neoplasm caused by Kaposi sarcoma-related herpesvirus. This review outlines our current understanding of the epidemiology, pathogenesis, clinical presentation, and staging for this disease. Recent research has informed a more comprehensive understanding of the epidemiology of KS in the post-antiretroviral therapy era, and highlights the continued need to better characterize the African endemic subtype. Advances in clinical oncology, including checkpoint inhibitors and new skin-directed therapies, have translated into exciting new developments for the future of KS treatment options.

Recent advances in HIV-associated Kaposi sarcoma

Kaposi sarcoma (KS) is a mesenchymal tumour caused by KS-associated herpesvirus and is an AIDS-defining illness. Despite a decline in incidence since the introduction of combination anti-retroviral therapy, KS remains the most common cancer in people living with HIV in sub-Saharan Africa, where it causes significant morbidity and mortality. This review reflects on recent epidemiological data as well as current management, unmet needs and future perspectives in the treatment of HIV-associated KS with particular emphasis on the potential role of immune checkpoint inhibitors.

Combination of CTLA-4 and PD-1 blockers for treatment of cancer

Targeting checkpoints of immune cell activation has been demonstrated to be the most effective approach for activation of anti-tumor immune responses. Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1), both inhibitory checkpoints commonly seen on activated T-cells have been found to be the most reliable targets for the treatment of cancer. Six drugs targeting PD-1 or its ligand PD-L1 and one drug targeting CTLA-4 have been approved for treatment of different types of cancers and several others are in advanced stages of development. The drugs when administered as monotherapy had dramatic increase in durable response rates and had manageable safety profile, but more than 50% of patients failed to respond to treatment. Combination of CTLA-4 and PD-1 blockers was then evaluated to increase the response rates in patients, and ipilimumab (anti-CTLA-4) plus nivolumab (anti-PD-1) combination was shown to significantly enhance efficacy in metastatic melanoma patients. Subsequently, ipilimumab plus nivolumab was approved for treatment of metastatic melanoma, advanced renal cell carcinoma and metastatic colorectal cancer with MMR/MSI-H aberrations. The success of combination encouraged multiple clinical studies in other cancer types. Efficacy of the combination has been shown in a number of published studies and is under evaluation in multiple ongoing studies. This review aims to support future research in combination immunotherapy by discussing the basic details of CTLA-4 and PD-1 pathways and the results from clinical studies that evaluated combination of CTLA-4 and PD-1/PD-L1 blockers.

Programmed cell death 1 protein and programmed death-ligand 1 inhibitors in the treatment of nonmelanoma skin cancer: A systematic review

BACKGROUND

Immunotherapy using programmed cell death 1 protein (PD-1) or programmed death-ligand 1 (PD-L1) inhibitors has been increasingly reported in a variety of nonmelanoma skin cancers (NMSCs).

OBJECTIVE

To analyze the evidence of PD-1 and PD-L1 inhibitors in the treatment of NMSC.

METHODS

A primary literature search was conducted with the PubMed, Cochrane Library, EMBASE, Web of Science, and CINAHL databases through October 28, 2018, to include studies on the use of PD-1 or PD-L1 inhibitors in patients for NMSC. Two reviewers independently performed study selection, data extraction, and critical appraisal.

RESULTS

This systematic review included 51 articles. The most robust evidence was in the treatment of Merkel cell carcinoma and cutaneous squamous cell carcinomas, as supported by phase 1 and 2 clinical trials. Treatment of basal cell carcinoma, cutaneous sarcoma, sebaceous carcinoma, and malignant peripheral nerve sheath tumor also showed benefit with PD-1/PD-L1 inhibitors, but data are limited. There does not appear to be efficacy for PD-1/PD-L1 inhibitors in cutaneous lymphomas.

LIMITATIONS

More investigation is needed to determine the efficacy, tumor responsiveness, and the safety profile of PD-1 and PD-L1 inhibitors in NMSC.

CONCLUSION

PD-1 and PD-L1 inhibitors exhibit treatment efficacy in a variety of NMSCs.

Kaposi sarcoma

Kaposi sarcoma (KS) gained public attention as an AIDS-defining malignancy; its appearance on the skin was a highly stigmatizing sign of HIV infection during the height of the AIDS epidemic. The widespread introduction of effective antiretrovirals to control HIV by restoring immunocompetence reduced the prevalence of AIDS-related KS, although KS does occur in individuals with well-controlled HIV infection. KS also presents in individuals without HIV infection in older men (classic KS), in sub-Saharan Africa (endemic KS) and in transplant recipients (iatrogenic KS). The aetiologic agent of KS is KS herpesvirus (KSHV; also known as human herpesvirus-8), and viral proteins can induce KS-associated cellular changes that enable the virus to evade the host immune system and allow the infected cell to survive and proliferate despite viral infection. Currently, most cases of KS occur in sub-Saharan Africa, where KSHV infection is prevalent owing to transmission by saliva in childhood compounded by the ongoing AIDS epidemic. Treatment for early AIDS-related KS in previously untreated patients should start with the control of HIV with antiretrovirals, which frequently results in KS regression. In advanced-stage KS, chemotherapy with pegylated liposomal doxorubicin or paclitaxel is the most common treatment, although it is seldom curative. In sub-Saharan Africa, KS continues to have a poor prognosis. Newer treatments for KS based on the mechanisms of its pathogenesis are being explored.

Successful Treatment of HIV-Associated Kaposi Sarcoma with Immune Checkpoint Blockade

Kaposi sarcoma (KS) is an incurable, human immunodeficiency virus (HIV)-associated malignancy. We reviewed 320 immunotherapy-treated patient records. Seventeen had HIV-associated malignancies, including nine men with KS. Median viral load was 20 copies/mL (range, undetectable to 549,704) and median CD4 count was 256 cells/μL (range, 10-603). Eight patients received nivolumab and one received pembrolizumab. Six patients (67%) achieved partial (N = 5) or complete remission (N = 1). No drug-related grade >2 toxicities occurred. In seven patients, CD4 counts increased (P = 0.09). Tissue and/or blood-derived circulating tumor DNA (ctDNA) was evaluated by next-generation sequencing. Four evaluable patients each showed anomalies in distinct genes: TP53, KRAS, TLL2, PTPN6 (tissue and/or ctDNA), and NF1 (ctDNA). Tumor mutational burden was low, and PD-L1 immunohistochemistry was negative (three and four assessable patients, respectively). Responders included patients with low CD4 counts, high HIV load, and/or visceral disease. In summary, checkpoint blockade demonstrated significant antitumor activity and low toxicity in patients with HIV-associated KS. Cancer Immunol Res; 6(10); 1129-35. ©2018 AACR.