Antitumor activity and safety of pembrolizumab in patients with advanced recurrent ovarian cancer: results from the phase II KEYNOTE-100 study

Blood natural killer cells during treatment in recurrent ovarian cancer

OBJECTIVE

Recent research indicated favorable prognostic impact of intratumoral natural killer (NK) cells in ovarian carcinoma (OC). The role of NK cells during chemotherapy in OC is unknown. We investigated impact of NK cells in OC patients treated with palliative chemotherapy.

METHODS

Participants receiving palliative chemotherapy for recurrent OC (N = 72) had prospectively blood samples at baseline and before cycle 2. NK cell counts were quantified by flow cytometry. NK cell activity was measured by the NK Vue^® assay, estimating interferon-gamma production. Overall survival (OS) was the primary endpoint. Cutoffs were predefined, NK numbers (≥184 × 10⁶ cells/L vs. <184 × 10⁶ cells/L) and NK activity (<200 pg/mL vs. ≥200 pg/mL).

RESULTS

Median OS in patients with low vs. high NK cell count at baseline was 7.1 months vs. 15.6 months (p = .028), respectively, and before cycle 2 was 5.7 vs. 17.3 months, p < .001, respectively. The difference in restricted mean survival (ΔRMST) was 5.7 months (95% CI: 3.3-8.0) at cycle 2 vs. 2.5 months (95% CI: -0.6 to 5.6) at baseline, showing a significant difference with no overlap of confidence intervals. In multivariate analyses, low NK cell count remained significant with a hazard ratio (HR)=2.83, 95% CI: 1.53-5.22, p = .001 (baseline) and HR = 3.34, 95% CI: 1.67-6.71, p = .001 (before cycle 2). Patients with both low NK count and NK activity at baseline (N = 20) had median OS 6.5 months vs. 11.5 months in patients with either high activity, high count or both (p = .007). In parallel, patients with both low NK activity and count at cycle 2 (N = 18) had a median survival of 4.0 months vs. 15.4 months (p < .001).

CONCLUSIONS

A low blood NK cell count in recurrent metastatic ovarian cancer during chemotherapy is associated with unfavorable prognostic impact. Early increase in survival difference based on NK cell status suggests an association between NK cell count and treatment benefit.

Modulation of Immune Infiltration of Ovarian Cancer Tumor Microenvironment by Specific Subpopulations of Fibroblasts

Tumor immune infiltration plays a key role in the progression of solid tumors, including ovarian cancer, and immunotherapies are rapidly emerging as effective treatment modalities. However, the role of cancer-associated fibroblasts (CAFs), a predominant stromal constituent, in determining the tumor-immune microenvironment and modulating efficacy of immunotherapies remains poorly understood. We have conducted an extensive bioinformatic analysis of our and other publicly available ovarian cancer datasets (GSE137237, GSE132289 and GSE71340), to determine the correlation of fibroblast subtypes within the tumor microenvironment (TME) with the characteristics of tumor-immune infiltration. We identified (1) four functional modules of CAFs in ovarian cancer that are associated with the TME and metastasis of ovarian cancer, (2) immune-suppressive function of the collagen 1,3,5-expressing CAFs in primary ovarian cancer and omental metastases, and (3) consistent positive correlations between the functional modules of CAFs with anti-immune response genes and negative correlation with pro-immune response genes. Our study identifies a specific fibroblast subtype, fibroblast functional module (FFM)2, in the ovarian cancer tumor microenvironment that can potentially modulate a tumor-promoting immune microenvironment, which may be detrimental toward the effectiveness of ovarian cancer immunotherapies.

Identification of serum cytokine clusters associated with outcomes in ovarian clear cell carcinoma

Serum cytokine and chemokine networks may reflect the complex systemic immunological interactions in cancer patients. Studying groups of cytokines and their networks may help to understand their clinical biology. A total of 178 cases of ovarian cancer were analyzed in this study, including 73 high-grade serous (HGSC), 66 clear cell (CCC) and 39 endometrioid carcinomas. Suspension cytokine arrays were performed with the patients’ sera taken before the primary surgery. Associations between each cytokine and clinicopathological factors were analyzed in all patients using multivariate linear regression models, and cluster analyses were performed for each histotype. In the multivariate analyses, twelve of 27 cytokines were correlated with histotypes. Cluster analyses in each histotype revealed 2 cytokine signatures S1 and S2 in HGSC, and similarly C1 and C2 in CCC. Twenty-two of 27 cytokines were commonly clustered in HGSC and CCC. Signature S1 and C1 included IL-2,6,8,15, chemokines and angiogenic factors, whereas signature S2 and C2 included IL-4,5,9,10,13, TNF-α and G-CSF. Four subgroups based on a high or low level for each signature were identified, and this cluster-based classification demonstrated significantly different progression-free and overall survivals for CCC patients (P = 0.00097 and P = 0.017).

Further Understanding of High-Grade Serous Ovarian Carcinogenesis: Potential Therapeutic Targets

High-grade serous ovarian carcinoma (HGSOC) is the most common type of ovarian cancer and the most lethal gynecologic malignancy due to advanced stage at presentation. Recent years have witnessed progress in the therapy of HGSOC with the introduction of PARP (poly-adenosine diphosphate ribose polymerase) inhibitors and the anti-angiogenic monoclonal antibody bevacizumab to the backbone of chemotherapy or as maintenance therapy after chemotherapy. The improved molecular understanding of ovarian cancer pathogenesis, which has brought these therapies into the clinic, aspires to extend the boundaries of therapies through elucidation of other molecular aspects of ovarian carcinogenesis. This accumulating knowledge has started to be translated to additional targeted therapies that are in various stages of development. These include inhibitors of the function of other proteins involved in homologous recombination deficiency (HRD), such as WEE1 kinase, ATM/ATR kinases and CDK12 inhibitors. Despite disappointing results with immune checkpoint inhibitors monotherapy, harnessing the immune system in HGSOC with combination therapies that promote antigen production and immune cell activation is an avenue being explored. This paper examines arising HGSOC therapies based on molecular understanding of pathogenesis.

Emerging role of immune checkpoint inhibitors in the treatment of ovarian cancer

INTRODUCTION

In recent years, ovarian cancer (OC) treatment has been enriched with many new target therapies, most of all antiangiogenic drugs and PARP inhibitors (PARPis), which have literally changed the natural history of the disease. The impressive results of immunotherapy in other malignancies, mainly melanoma and lung cancer, and the good signals of activity in gynecological neoplasms like cervical and microsatellite instable (MSI-H) endometrial cancer, opened the space to the introduction of immune-stimulatory drugs in ovarian cancer.

AREA COVERED

The goal of this article is to summarize the newest evidence on the use of immune check point inhibitors in OC trying to explain why, at present, this strategy has failed to improve clinical outcome and focusing on the possible strategies to overcome treatment failure.

EXPERT OPINION

Although numerous trials have been undertaken, only scanty results have been obtained so far with immune check-point inhibitors (ICIs) in OC either when used as single agents or in combination with antiangiogenic therapy and ongoing trials are exploring the association of ICIs with PARPis and other ICIs. A better knowledge of predictive biomarkers of response and mechanisms of immunotherapy resistance, will help in identifying the most appropriate population to treat with ICIs.

The current landscape of molecular profiling in the treatment of epithelial ovarian cancer

Advances in next generation sequencing have allowed for rapid and economical germline and tumor genomic profiling. Targeted therapies based on molecular tumor profiling are now integrated into treatment guidelines for many solid tumors. In epithelial ovarian cancer, 50% of tumors possess damaging mutations in homologous recombination repair genes (aka homologous recombination deficiency or HRD) which includes the BRCA genes. Deleterious BRCA mutations and HRD have recently emerged as predictive biomarkers for the use of PARP inhibitors in ovarian cancer. Every patient with ovarian cancer must be referred for genetic counseling and germline testing for BRCA mutations. Multigene panel genetic testing may be more informative and cost-effective than limited testing of cancer susceptibility genes. Patients without a germline deleterious BRCA mutation must be assessed for a somatic BRCA mutation. Assays for HRD may help guide treatment options in women who do not have a BRCA mutation. Currently, all patients with a germline or somatic BRCA mutation should be offered upfront maintenance therapy with a PARP inhibitor. During May 2020, options for maintenance therapy with a PARP inhibitor were expanded to patients with HRD and HR-proficient tumors.

Avelumab: search for combinations of immune checkpoint inhibition with chemotherapy

INTRODUCTION

Immune checkpoint inhibition (ICI) has proved successful for selected tumors and a subpopulation of patients. The human monoclonal IgG1 antibody (mAB) avelumab capable of mediating antibody-dependent cytotoxicity (ADCC) lysis is directed to programmed death ligand-1 (PD-L1) of tumor cells and is tested in trials aiming to improve ICI in combination with chemotherapeutic drugs.

AREAS COVERED

This article presents an overview of the current trials to enhance ICI regimens using avelumab in combination with chemotherapeutics, antiangiogenetic drugs, and immunomodulators. Predictive factors for this kind of immunochemotherapy are discussed.

EXPERT OPINION

Clinical data demonstrate that avelumab shows efficacy in cancer patients against Merkel cell carcinoma (MCC), renal cell carcinoma (RCC), and urothelial cancers as single agent. Furthermore, avelumab in combination with axitinib in RCC increases survival and exhibits activity in combination with docetaxel in urothelial carcinoma. However, several other immunochemotherapy trials for ovarian cancer, gastric cancer, and non-small lung cancer (NSCLC) showed no activity due to factors disfavoring administration of immunotherapy combos.

Association of PD-L1 expression by immunohistochemistry and gene microarray with molecular subtypes of ovarian tumors

Identifying patients who respond to immune checkpoint blockade (ICB) is a significant challenge in oncology. While PD-L1 expression by immunohistochemistry (IHC) is the current diagnostic gold standard for patient selection, it nevertheless does not capture all patients who may respond to ICB. Recent gene expression studies in high-grade serous ovarian carcinoma have defined an immunoreactive molecular subtype that has a measurable difference in patient survival compared with non-immunoreactive subtypes, but no studies have yet demonstrated its impact on predicting response to ICB. As a step toward establishing the predictive value of gene expression classifiers in ICB, we assessed the relationship between PD-L1 IHC and molecular subtypes of ovarian epithelial cancer. This was done by analyzing a total of 93 tissue specimens from patients with stage III and IV disease, and comparing PD-L1 IHC with gene expression by Agilent microarrays using TCGA-defined subtypes. We showed that ovarian tumors with elevated IHC PD-L1 expression are most strongly associated with immunoreactive subtype as compared with other molecular subtypes, reaching statistical significance against differentiated (Dunn's test, 33.39, p = 0.0003) and mesenchymal (39.63, p < 0.0001) subtypes. Comparing PD-L1 scoring with CPS vs. TPS showed similar trends, but with stronger correlation strength when using CPS (Kruskal-Wallis, H = 27.52, p < 0.0001), as opposed to TPS (H = 25.04, p < 0.0001). Interestingly, while PD-L1 gene expression by microarray was significantly increased in the immunoreactive subtype (H = 20.25, p = 0.0002), it showed a positive but relatively poor correlation to IHC. Overall, the results demonstrate potential value in use of the molecular classifier to select patients for ICB, pending further studies that assess its ability to predict treatment outcomes. In the future, integration of cellular, protein, and genomic biomarkers in the tumor and tumor microenvironment may improve current methods of predicting treatment response.

Application and reflection of genomic scar assays in evaluating the efficacy of platinum salts and PARP inhibitors in cancer therapy

Defective DNA repair is one of the most important features of tumors. BRCA1/2 participates in homologous recombination repair as a key tumor suppressor gene. BRCA1/2 mutation is an important biomarker for predicting the sensitivity of platinum salts and Poly (ADP-ribose) polymerase (PARP) inhibitors in breast cancer, ovarian cancer, and other cancers. However, epigenetic modifications and other mutations in homologous recombination repair (HRR) genes can also cause homologous recombination deficiency (HRD). Patients with no BRCA1/2 mutations, but bearing similar molecular phenotypes (BRCAness) can still obtain clinical benefits from treatment with platinum salts or PARP inhibitors. Therefore, an accurate assessment of HRD is essential for the formulation of personalized treatments. However, methods to identify HRD in tumors vary and are controversial. Currently, genomic scar assays have been used in multiple clinical trials to assess patient clinical benefit. This review summarizes the therapeutic effects of platinum salts and PARP inhibitors in breast and ovarian cancer, clarifies the predictive value of genomic scar assays in evaluating the clinical benefit of different patient groups and treatment options, and proposes the limitations and optimization of current HRD scoring methods. Using and optimizing genomic scar assays can help to accurately screen the population with the most benefit, expand the scope of drug application, and make the most suitable clinical decision based on individual differences.

Definition and Independent Validation of a Proteomic-Classifier in Ovarian Cancer

Simple Summary

The heterogeneity of epithelial ovarian cancer and its associated molecular biological characteristics are continuously integrated in the development of therapy guidelines. In a next step, future therapy recommendations might also be able to focus on the patient’s systemic status, not only the tumor’s molecular pattern. Therefore, new methods to identify and validate host-related biomarkers need to be established. Using mass spectrometry, we developed and independently validated a blood-based proteomic classifier, stratifying epithelial ovarian cancer patients into good and poor survival groups. We also determined an age dependence of the prognostic performance of this classifier and its association with important biological processes. This work highlights that, just like molecular markers of the tumor itself, the systemic condition of a patient (partly reflected in proteomic patterns) also influences survival and therapy response and could therefore be integrated into future processes of therapy planning.

Abstract

Mass-spectrometry-based analyses have identified a variety of candidate protein biomarkers that might be crucial for epithelial ovarian cancer (EOC) development and therapy response. Comprehensive validation studies of the biological and clinical implications of proteomics are needed to advance them toward clinical use. Using the Deep MALDI method of mass spectrometry, we developed and independently validated (development cohort: n = 199, validation cohort: n = 135) a blood-based proteomic classifier, stratifying EOC patients into good and poor survival groups. We also determined an age dependency of the prognostic performance of this classifier, and our protein set enrichment analysis showed that the good and poor proteomic phenotypes were associated with, respectively, lower and higher levels of complement activation, inflammatory response, and acute phase reactants. This work highlights that, just like molecular markers of the tumor itself, the systemic condition of a patient (partly reflected in proteomic patterns) also influences survival and therapy response in a subset of ovarian cancer patients and could therefore be integrated into future processes of therapy planning.

Morphological and molecular heterogeneity of epithelial ovarian cancer: Therapeutic implications

Ovarian epithelial cancer (OEC) is the most lethal gynecologic malignancy. Despite current chemotherapeutic and surgical options, this high lethality can be attributed to multiple factors, including late-stage presentation. In order to optimize OEC treatment, it is important to highlight that it is composed of five main subtypes: high-grade serous ovarian carcinoma (HGSOC), low-grade serous ovarian carcinoma (LGSOC), endometrioid ovarian carcinoma (EOC), ovarian clear cell carcinoma (CCOC), and mucinous ovarian carcinoma (MOC). These subtypes differ in their precursor lesions, as well as in epidemiological, morphological, molecular and clinical features. OEC is one of the tumours in which most pathogenic germline mutations have been identified. Accordingly, up to 20% OC show alterations in BRCA1/2 genes, and also, although with a lower frequency, in other low penetrance genes associated with homologous recombination deficiency (HRD), mismatch repair genes (Lynch syndrome) and TP53. The most important prognostic factor is the 2014 FIGO staging, while older age is also associated with worse survival. HGSOC in all stages and CCC and MOC in advanced stages have the worse prognosis among histological types. Molecular markers have emerged as prognostic factors, particularly mutations in BRCA1/2, which are associated with a better outcome. Regarding treatment, whereas a proportion of HGSOC is sensible to platinum-based treatment and PARP inhibitors due to HRD, the rest of the histological types are relatively chemoresistant. New treatments based in specific molecular alterations are being tested in different histological types. In addition, immunotherapy could be an option, especially for EOC carrying mismatch repair deficiency or POLE mutations.

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The five different histological types have different precursor lesions and epidemiological, morphological, genetic, epigenetic and clinical features.

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Histological type is an important prognostic factor.

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Drugs targeting homologous recombination deficiency have been approved for treatment.

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The use of immunotherapy is limited due to lack of predictive biomarkers

Combined pembrolizumab and pegylated liposomal doxorubicin in platinum resistant ovarian cancer: A phase 2 clinical trial

OBJECTIVE

Pegylated liposomal doxorubicin (PLD) in vitro may have immunomodulatory abilities and preclinical evidence suggests it synergizes with immune checkpoint blockade. We hypothesized that combining PLD and pembrolizumab would be active in patients with platinum-resistant ovarian cancer (PROC).

METHODS

This was a single-arm, multi-center phase II trial. Eligible patients had PROC with ≤2 prior lines of cytotoxic therapy for recurrent or persistent disease. Twenty-six patients were enrolled and given pembrolizumab 200 mg intravenously (IV) every 3 weeks and PLD 40 mg/m² IV every 4 weeks. Patients were assessed radiographically every 8 weeks. The primary endpoint was clinical benefit rate (CBR), defined as complete response (CR) + partial response (PR) + stable disease (SD) ≥24 weeks. The study was powered to detect an improvement in CBR from 25% to 50%, with rejection of the null hypothesis if at least 10 patients achieved clinical benefit. T-cell inflamed gene expression profiles (GEP) and PD-L1 were assessed and correlated with clinical outcome.

RESULTS

Twenty-three patients were evaluable for best overall response. The study satisfied its primary endpoint, with 12 patients achieving clinical benefit for a CBR of 52.2% (95% CI 30.6-73.2%). There were 5 PRs (21.7%) and 1 CR (4.3%), for an overall response rate (ORR) of 26.1%. Six patients had SD lasting at least 24 weeks. Combination therapy was well tolerated without unexpected toxicities.

CONCLUSIONS

The combination of pembrolizumab and PLD was manageable, without unexpected toxicities, and showed preliminary evidence of clinical benefit in the treatment of platinum resistant ovarian cancer. ORR and median PFS of combination therapy in this study was higher than historical comparisons of PLD alone or anti-PD-1/PD-L1 agents alone.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT02865811.

Significance of tumor mutation burden combined with immune infiltrates in the progression and prognosis of ovarian cancer

Background

Ovarian cancer (OC) is the most malignant tumor in the female reproductive system. About 75% of OC in complete remission of clinical symptoms still develop a recurrence. Therefore, searching for new treatment methods plays an important role in improving the prognosis of OC.

Methods

We downloaded the MAF files, RNA-seq data and clinical information from the TCGA database. The “maftools” package in R software was used to visualize the OC mutation data. We calculated the tumor mutation burden (TMB) of OC and analyzed its correlation with clinicopathological parameters and prognostic value. Tumor mutation burden related signature model was constructed to predict the overall survival (OS) of OC.

Results

The results revealed that there was a statistical correlation between TMB and FIGO stage, grade and tumor residual size of ovarian cancer patients. The Kaplan–Meier curve indicated that a high TMB is associated with better clinical outcomes of OC. The difference analysis indicated 24 upregulated genes and 619 downregulated genes in the high-TMB group compared with the low-TMB group. Besides, the TMBRS model based on five hub genes (RBMS3, PLA2G5, CDH2, AMHR2 and ADAMTS8) was constructed to predict the OS of OC. The ROC curve and validation data sets all revealed that the TMBRS model was reliable in predicting recurrence risk. Immune microenvironment analysis indicated the correlations between TMB and infiltrating immune cells.

Conclusions

Our results suggest that TMB plays an important role in the prognosis and guiding immunotherapy of OC. By detecting the TMB of OC, clinicians can more accurately treat patients with immunotherapy, thereby improving their survival rate.

Profound Functional Suppression of Tumor-Infiltrating T-Cells in Ovarian Cancer Patients Can Be Reversed Using PD-1-Blocking Antibodies or DARPin® Proteins

PD-1/PD-L1 blockade has revolutionized the field of immunooncology. Despite the relative success, the response rate to anti-PD-1 therapy requires further improvements. Our aim was to explore the enhancement of T-cell function by using novel PD-1-blocking proteins and compare with clinically approved monoclonal antibodies (mAbs). We isolated T-cells from the ascites and tumor of 17 patients with advanced epithelial ovarian cancer (EOC) and analyzed the effects using the mAbs nivolumab and pembrolizumab and two novel engineered ankyrin repeat proteins (DARPin® proteins). PD-1 blockade with either mAb or DARPin® molecule significantly increased the release of IFN-γ, granzyme B, IL-2, and TNF-α, demonstrating successful reinvigoration. The monovalent DARPin® protein was less effective compared to its bivalent equivalent, demonstrating that bivalency brings an additional benefit to PD-1 blockade. Overall, we found a higher fold increase of lymphokine secretion in response to the PD-1 blockade by tumor-derived T-cells; however, the absolute amounts were significantly lower compared to the release from ascites-derived T-cells. Our results demonstrate that PD-1 blockade can only partially reinvigorate functionally suppressed T-cells from EOC patients. This warrants further investigation preferably in combination with other therapeutics. The study provides an early pilot proof-of-concept for the potential use of DARPin® proteins as eligible alternative scaffold proteins to block PD-1.

Brain Metastases from Ovarian Cancer: Current Evidence in Diagnosis, Treatment, and Prognosis

With this review, we provide the state of the art concerning brain metastases (BMs) from ovarian cancer (OC), a rare condition. Clinical, pathological, and molecular features, treatment options, and future perspectives are comprehensively discussed. Overall, a diagnosis of high-grade serous OC and an advanced disease stage are common features among patients who develop brain metastases. BRCA1 and BRCA2 gene mutations, as well as the expression of androgen receptors in the primary tumor, are emerging risk and prognostic factors which could allow one to identify categories of patients at greater risk of BMs, who could benefit from a tailored follow-up. Based on present data, a multidisciplinary approach combining surgery, radiotherapy, and chemotherapy seem to be the best approach for patients with good performance status, although the median overall survival (<1 year) remains largely disappointing. Hopefully, novel therapeutic avenues are being explored, like PARP inhibitors and immunotherapy, based on our improved knowledge regarding tumor biology, but further investigation is warranted.

A multicenter phase II randomized trial of durvalumab (MEDI-4736) versus physician's choice chemotherapy in recurrent ovarian clear cell adenocarcinoma (MOCCA)

BACKGROUND

The optimal treatment of recurrent ovarian clear cell carcinoma remains unknown. There is increasing rationale to support the role of immune checkpoint inhibitors targeting the programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) axis in ovarian clear cell carcinoma.

PRIMARY OBJECTIVE

To evaluate the efficacy of durvalumab (MEDI-4736) compared with standard chemotherapy in patients with recurrent ovarian clear cell carcinoma.

STUDY HYPOTHESIS

Patients with recurrent ovarian clear cell carcinoma treated with durvalumab will have improved progression-free survival compared with those treated with chemotherapy of physician's choice.

TRIAL DESIGN

The MOCCA study is a multicenter, open-label, randomized phase II trial in patients with recurrent ovarian clear cell carcinoma, which recruited from eight sites across Gynecologic Cancer Group Singapore (GCGS), Korean Gynecologic-Oncology Group (KGOG), and Australia New Zealand Gynecological Oncology Group (ANZGOG). Enrolled patients were randomized in a 2:1 ratio to receive durvalumab or physician's choice of chemotherapy until disease progression, intolerable toxicity, or withdrawal of patient consent.

MAJOR INCLUSION/EXCLUSION CRITERIA

Eligible patients required histologically documented diagnosis of recurrent ovarian clear cell carcinoma, as evidenced by WT1 negativity. All patients must have been of Eastern Cooperative Oncology Group (ECOG) performance status 2 or better, and have had previous treatment with, and progressed or recurred after prior platinum-based chemotherapy. No more than four prior lines of treatment were allowed and prior immune checkpoint inhibitor treatment was not permitted.

PRIMARY ENDPOINTS

The primary endpoint was the median progression-free survival following treatment with durvalumab, compared with physician's choice of chemotherapy. Progression-free survival was defined as the time from the first day of treatment to the first observation of disease progression, or death due to any cause, or last follow-up.

SAMPLE SIZE

The target sample size was 46 patients.

ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS

Accrual has been completed and results are expected to be presented by mid-2021.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT03405454.

Targeted therapies in gynecological cancers: a comprehensive review of clinical evidence

Advanced and recurrent gynecological cancers are associated with poor prognosis and lack of effective treatment. The developments of the molecular mechanisms on cancer progression provide insight into novel targeted therapies, which are emerging as groundbreaking and promising cancer treatment strategies. In gynecologic malignancies, potential therapeutic targeted agents include antiangiogenic agents, poly (ADP-ribose) polymerase (PARP) inhibitors, tumor-intrinsic signaling pathway inhibitors, selective estrogen receptor downregulators, and immune checkpoint inhibitors. In this article, we provide a comprehensive review of the clinical evidence of targeted agents in gynecological cancers and discuss the future implication.

Early Onset Immune-Related Adverse Event to Identify Pseudo-Progression in a Patient With Ovarian Cancer Treated With Nivolumab: A Case Report and Review of the Literature

Background: Immune checkpoint inhibitors (ICIs) have shown clinical benefit in many advanced tumors, however, pseudo-progression is a noted phenomenon of ICIs characterized by radiologic enlargement of the tumor burden, followed by regression. How to differentiate pseudo-progression from progression remains a critical clinical issue. Recent studies have demonstrated the association between immune-related adverse events (irAEs) and efficacy of ICIs. Here we demonstrated an ovarian cancer patient treated with nivolumab in whom the early-onset irAE was identified to differentiate pseudo-progression from progression.

Case presentation: Here we present the case of a 47-years-old woman with histopathologically confirmed diagnosis of metastatic ovarian cystadenocarcinoma. Immunohistochemical examination showed 10% of tumor cells to express the programmed cell death receptor ligand 1 (PD-L1) and a 381-gene panel sequencing in a College of American Pathologists (CAP) certificated lab revealed a moderate mutational tumor burden with 5.7 Mutants/Mb. The patient received nivolumab 100 mg every 2 weeks as a fourth line treatment. Within the first 2 months, the tumor volume increased by 23.6%. However, the patient experienced an elevation of Alanine aminotransferase (ALT) and Aspartate aminotransmerase (AST), which was diagnosed as the immune-related hepatitis. Thus, the treatment continued and afterwards, the patient reached a partial response (PR) to nivolumab and the progression-free survival was 9 months.

Conclusion: To our knowledge, this is the first case describing early-onset immune-related adverse events to identify pseudo-progression in a patient with ovarian cancer treated with nivolumab, and PD-L1 expression level may be a predictive biomarker in the immunotherapy of ovarian cancer.

Patient-derived ovarian cancer organoids capture the genomic profiles of primary tumours applicable for drug sensitivity and resistance testing

The use of primary patient-derived organoids for drug sensitivity and resistance testing could play an important role in precision cancer medicine. We developed expandable ovarian cancer organoids in < 3 weeks; these organoids captured the characteristics of histological cancer subtypes and replicated the mutational landscape of the primary tumours. Seven pairs of organoids (3 high-grade serous, 1 clear cell, 3 endometrioid) and original tumours shared 59.5% (36.1–73.1%) of the variants identified. Copy number variations were also similar among organoids and primary tumours. The organoid that harboured the BRCA1 pathogenic variant (p.L63*) showed a higher sensitivity to PARP inhibitor, olaparib, as well as to platinum drugs compared to the other organoids, whereas an organoid derived from clear cell ovarian cancer was resistant to conventional drugs for ovarian cancer, namely platinum drugs, paclitaxel, and olaparib. The overall success rate of primary organoid culture, including those of various histological subtypes, was 80% (28/35). Our data show that patient-derived organoids are suitable physiological ex vivo cancer models that can be used to screen effective personalised ovarian cancer drugs.

Efficacy of PD-1/PD-L1 blockade monotherapy in clinical trials

Background:

Inhibitors targeting programmed cell death 1 (PD-1) and programmed death-ligand 1 (PD-L1) have unprecedented effects in cancer treatment. However, the objective response rates (ORRs), progression-free survival (PFS), and overall survival (OS) of PD-1/PD-L1 blockade monotherapy have not been systematically evaluated.

Methods:

We searched Embase, PubMed, and Cochrane database from inception to July 2019 for prospective clinical trials on single-agent PD-1/PD-L1 antibodies (avelumab, atezolizumab, durvalumab, cemiplimab, pembrolizumab, and nivolumab) with information regarding ORR, PFS, and OS.

Results:

Totally, 28,304 patients from 160 perspective trials were included. Overall, 4747 responses occurred in 22,165 patients treated with PD-1/PD-L1 monotherapy [ORR, 20.21%; 95% confidence interval (CI), 18.34–22.15%]. Compared with conventional therapy, PD-1/PD-L1 blockade immunotherapy was associated with more tumor responses (odds ratio, 1.98; 95% CI, 1.52–2.57) and better OS [hazard ratio (HR), 0.75; 95% CI, 0.67–0.83]. The ORRs varied significantly across cancer types and PD-L1 expression status. Line of treatment, clinical phase and drug target also impacted the response rates in some tumors. A total of 2313 of 9494 PD-L1 positive patients (ORR, 24.39%; 95% CI, 22.29–26.54%) and 456 of 4215 PD-L1 negative patients (ORR, 10.34%; 95% CI, 8.67–12.14%) achieved responses. For PD-L1 negative patients, the ORR (odds ratio, 0.92; 95% CI, 0.70–1.20) and PFS (HR, 1.15; 95% CI, 0.87–1.51) associated with immunotherapy and conventional treatment were similar. However, PD-1/PD-L1 blockade monotherapy decreased the risk of death in both PD-L1 positive (HR, 0.66; 95% CI, 0.60–0.72) and PD-L1 negative (HR, 0.86; 95% CI, 0.74–0.99) patients compared with conventional therapy.

Conclusion:

The efficacies associated with PD-1/PD-L1 monotherapy vary significantly across cancer types and PD-L1 expression. This comprehensive summary of clinical benefit from immunotherapy in cancer patients provides an important guide for clinicians.

Immune checkpoint inhibitors in women with gynecologic cancers: Practical considerations

Immune checkpoint inhibitors are an exciting new class of cancer therapeutics. Recently, a PD-1 inhibitor has been approved by the Food and Drug Administration for several indications that are relevant to patients with gynecologic malignancies. In this review, we explore the clinical considerations for the use of checkpoint inhibitor therapy in this population. Specifically, we will discuss the approved indications, recommended dosing, clinical monitoring while on treatment, common adverse events, and treatment of adverse events should they arise. Additionally, we will review mechanisms of resistance and other challenges associated with the use of checkpoint inhibitors. We will conclude with a discussion of possible future directions for immunotherapy in women with gynecologic cancers.

Preclinical and Clinical Immunotherapeutic Strategies in Epithelial Ovarian Cancer

In the past 20 years, the immune system has increasingly been recognized as a major player in tumor cell control, leading to considerable advances in cancer treatment. While promising with regards to melanoma, renal cancer and non-small cell lung cancer, immunotherapy provides, for the time being, limited success in other cancers, including ovarian cancer, potentially due to insufficient immunogenicity or to a particularly immunosuppressive microenvironment. In this review, we provide a global description of the immune context of ovarian cancer, in particular epithelial ovarian cancer (EOC). We describe the adaptive and innate components involved in the EOC immune response, including infiltrating tumor-specific T lymphocytes, B lymphocytes, and natural killer and myeloid cells. In addition, we highlight the rationale behind the use of EOC preclinical mouse models to assess resistance to immunotherapy, and we summarize the main preclinical studies that yielded anti-EOC immunotherapeutic strategies. Finally, we focus on major published or ongoing immunotherapy clinical trials concerning EOC.

Cutaneous metastasis of PD-L1 positive ovarian carcinoma

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Ovarian cancer (OC) metastasizes cutaneous in up to 6% of cases.

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Cutaneous metastasis to the vulva is rare; with only one prior report in the literature.

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Resection of cutaneous metastasis offers symptom relief as well as a potential survival benefit.

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Molecular tumor profiling should be employed to expand therapy options.

Endometriosis-Associated Ovarian Cancer: The Origin and Targeted Therapy

Endometrial cysts (ECs) are thought to be the origin of endometriosis-associated ovarian cancer (EAOC). A hypothesis that the oxidative stress of iron in cysts causes “malignant transformation of ECs” has been proposed, but this has not been verified. Several population-based studies showed that endometriosis was a risk factor but did not reflect the “malignant transformation of ECs”. A review showed that most patients were diagnosed with EAOC early in monitoring following detection of ECs, and that these cases might have been cancer from the start. Epidemiologically, EAOC was reduced by hysterectomy rather than by cystectomy of ECs. Gene mutation analyses identified oncogenic mutations in endometriosis and normal endometrium and revealed that the same mutations were present at different endometriotic lesions. It was also shown that most of the gene mutations found in endometriosis occurred in normal endometrium. Taking together, EAOC might be caused by eutopic endometrial glandular epithelial cells with oncogenic mutations that have undergone menstrual blood reflux and engrafted in the ovary, rather than by low-risk ECs acquiring oncogenic mutations and becoming malignant. This review discusses the mechanisms of EAOC development and targeted therapy based on genetic variation in EAOC with a focus on eutopic endometrium.

Current and future strategies for treatment of ovarian clear cell carcinoma

Ovarian clear cell carcinoma (OCCC) is one of the five histological types of epithelial ovarian cancer (EOC). OCCC comprises 23% of all EOC cases in Japan, whereas the rate of OCCC in North America and Europe is much lower. OCCC is generally categorized as a rare gynecologic malignancy, and there is limited evidence for specific treatment. The clinical basis for treatment of OCCC is mostly based on retrospective studies, many of which were performed in Japan. Until recently, most randomized clinical trials for EOC have included OCCC; therefore, current treatment for OCCC is basically the same as that for other histologic types of EOC. However, the clinical characteristics of OCCC differ from those of high-grade serous carcinoma, particularly for chemosensitivity, and there is a need to develop new treatment for OCCC. The molecular background of OCCC has unique features: tumors are usually negative for p53 mutations and positive for ARID1A and/or PIK3CA mutations, whereas p53 mutations are common in high-grade serous or endometrioid carcinomas. These features may help in development of new treatment for OCCC. In this review, we described the current evidence for treatment of OCCC, including surgery, radiotherapy, chemotherapy, molecular targeted therapy and immunotherapy, and we discuss ongoing clinical trials and preclinical studies of new treatment approaches for OCCC.

BRCA Mutations, Homologous DNA Repair Deficiency, Tumor Mutational Burden, and Response to Immune Checkpoint Inhibition in Recurrent Ovarian Cancer

PURPOSE

Homologous DNA repair-deficient (HRD) ovarian cancers (OCs), including those with BRCA1/2 mutations, have higher levels of genetic instability, potentially resulting in higher immunogenicity, and have been suggested to respond better to immune checkpoint inhibitors (ICIs) than homologous DNA repair-proficient OCs. However, clinical evidence is lacking. The study aimed to evaluate the associations between BRCA1/2 mutations, HRD, and other genomic parameters and response to ICIs and survival in OC.

METHODS

This is a single-institution retrospective analysis of women with recurrent OC treated with ICIs. BRCA1/2 mutation status and clinicopathologic variables were abstracted from the medical records. Targeted and whole-exome sequencing data available for a subset of patients were used to assess tumor mutational burden (TMB), HRD, and fraction of genome altered (FGA). ICI response was defined as lack of disease progression for ≥ 24 weeks. Associations of BRCA1/2 status and genomic alterations with progression-free survival (PFS) and overall survival (OS) were determined using Cox proportional hazards models.

RESULTS

Of the 143 women treated with ICIs, 134 had known BRCA1/2 mutation status. Deleterious germline or somatic BRCA1/2 mutations were present in 31 women (24%). There was no association between presence of BRCA1/2 mutations and response (P = .796) or survival. Genomic analysis in 73 women found no association between TMB (P = .344) or HRD (P = .222) and response, PFS, or OS. There were also no significant differences in somatic genetic alterations between responders and nonresponders. High FGA was associated with an improvement in PFS (P = .014) and OS (P = .01).

CONCLUSION

TMB, BRCA1/2 mutations, and HRD are not associated with response or survival, cautioning against their use as selection criteria for ICI in recurrent OC. FGA should be investigated further as a biomarker of response to immunotherapy in OC.

Sustained response to pembrolizumab without prior chemotherapy in high-grade serous ovarian carcinoma with CSMD3 mutation

•Metastatic CSMD3 mutated HGSOC showed objective and sustained response to pembrolizumab.•The tumor was massively infiltrated by CD8⁺ T cells while PD-L1 TPS was at 10%.•CSMD3 mutated HGSOC showed up-regulation of CCL5 and CXCL9.

Utility of serum CA-125 monitoring in patients with ovarian cancer undergoing immune checkpoint inhibitor therapy

OBJECTIVE

This study aimed to evaluate the utility of serum cancer antigen-125 (CA-125) levels to monitor patients with epithelial ovarian cancer (EOC) undergoing immune checkpoint inhibitor (ICI) therapy.

METHOD

This was a single-center retrospective review of all patients with EOC who were treated with ICI therapy from January 2013 to May 2017. This study compared the percentage change in baseline CA-125 in patients who had clinical benefit, defined as complete response, partial response, or stable disease by RECIST 1.1, with duration ≥24 weeks, versus those who did not. The groups were compared by Wilcoxon rank-sum test.

RESULTS

Fifty-nine (66%) of 89 patients who underwent ICI therapy had CA-125 data at baseline and during treatment. Of those who derived clinical benefit, 11/15 (73%) experienced an increase in CA-125 from baseline to end of treatment. Of those who did not derive clinical benefit, 36/44 (82%) experienced a CA-125 increase (p = 0.48). The average % increase from baseline to within 12 weeks of treatment initiation for patients with and without clinical benefit was 34% and 195%, respectively (p = 0.008).

CONCLUSION

Our analysis demonstrates a statistically significant difference in the magnitude of increase in CA-125 levels within the first 12 weeks of treatment between patients who achieved clinical benefit and those who did not. However, both groups of patients were equally likely to experience an increase in CA-125 within 12 weeks. These findings suggest that physicians should apply caution when using early CA-125 data to guide treatment decisions for patients with EOC undergoing ICI therapy.

Immunotherapy for platinum-resistant ovarian cancer

Ovarian cancer is characterized by a high mortality on incidence ratio. Although the majority of patients achieve complete response after primary treatment, approximately 65-80% of patients recur with the first 5 years. Platinum-free interval is one of the main prognostic factors. Patients recurring with 6 months within the end of platinum-based chemotherapy are characterized by poor prognosis. To date no effective treatment modality are identified for those patients. The mainstay of treatment for platinum-resistant ovarian cancer is single agent chemotherapy. Other treatment modalities have tested in this setting with discouraging results. Growing evidence suggested that immunotherapy would improve outcomes of patients with various types of solid tumors including melanoma, non-small cell lung cancer as well as uterine malignancies. Here, we reviewed current evidence on the adoption of immunotherapy in platinum-resistant ovarian cancer. To date no mature evidence supports the routine adoption of immunotherapy in ovarian cancer patients. Further strategies have to be explored.

Tamrintamab pamozirine (SC-003) in patients with platinum-resistant/refractory ovarian cancer: Findings of a phase 1 study

OBJECTIVE

Epithelial ovarian carcinoma (EOC) is diagnosed at advanced stage in the majority of women and, despite being initially chemosensitive, eventually recurs and develops resistance to known therapies. SC-003 is a pyrrolobenzodiazepine-based antibody-drug conjugate targeting dipeptidase 3 (DPEP3), a membrane-bound dipeptidase associated with tumor-initiating cells in patient-derived EOC xenograft models. This first-in-human phase 1a/1b study evaluated the safety/tolerability, pharmacokinetics, and preliminary antitumor activity of SC-003 alone or in combination with budigalimab (formerly ABBV-181), an antibody targeting PD-1, in patients with platinum-resistant/refractory EOC (NCT02539719).

METHODS

Patients received SC-003 at 1 of 6 dose levels (0.025-0.4 mg/kg) every 3 weeks (Q3W), utilizing a standard 3 + 3 design (dose-limiting toxicity [DLT] period: 21 days). Patients with DPEP3-positive tumors were enrolled in the dose-expansion phase of the study and treated with SC-003 monotherapy or in combination with budigalimab.

RESULTS

Seventy-four patients (n = 29, dose escalation; n = 45, dose expansion; n = 3 budigalimab combination) were enrolled and received ≥1 dose of study drug. One DLT occurred (grade 3 ileus) but was considered unrelated to study drug. The MTD for the Q3W schedule was 0.3 mg/kg and the SC-003 doses selected for the dose-expansion phase of the study were 0.3 mg/kg and 0.2 mg/kg. The most common treatment-emergent adverse events were fatigue, nausea, decreased appetite, pleural effusion, abdominal pain, and peripheral edema. The overall response rate was low (4%), and responses were not durable. Post-hoc examination of antitumor activity suggested a higher response rate in patients with higher DPEP3 expression.

CONCLUSIONS

SC-003 lacked the requisite safety profile and antitumor activity to warrant further development.

First-Line Management of Advanced High-Grade Serous Ovarian Cancer

PURPOSE OF REVIEW

Epithelial ovarian cancer is a disease that encompasses a number of histologically and molecularly distinct entities; the most prevalent subtype being high-grade serous (HGS) carcinoma. Standard first-line treatment of advanced HGS carcinoma includes cytoreductive surgery plus intravenous paclitaxel/platinum-based chemotherapy. Despite excellent responses to initial treatment, the majority of patients develop recurrent disease within 3 years. The introduction of the vascular endothelial growth factor (VEGF) inhibitor, bevacizumab, and poly(ADP-ribose) polymerase (PARP) inhibitors into first-line management has changed the outlook for this lethal disease. In this review, we summarise the most recent clinical trials that determine current primary therapy of advanced HGS carcinoma and the ongoing trials that aim to change management in the future.

RECENT FINDINGS

Recent phase III clinical trials have shown that delayed primary surgery after completing neo-adjuvant chemotherapy is non-inferior to immediate primary surgery, but could provide a survival benefit in FIGO (International Federation of Gynecology and Obstetrics) stage IV disease. The use of weekly intravenous chemotherapy regimens has not been proven to be more effective than standard 3-weekly regimens in Western patient populations, and the use of intraperitoneal chemotherapy remains controversial in the first-line setting. In contrast, newer systemic anti-cancer therapies targeting angiogenesis and/or HR-deficient tumours have been successfully incorporated into front-line therapeutic regimens to treat HGS carcinoma. Recent results from randomised trials investigating the use of PARP inhibitors as monotherapy and in combination with the anti-angiogenic agent, bevacizumab, have demonstrated highly impressive efficacy when combined with traditional first-line multi-modality therapy. Management of HGS carcinoma is evolving, but further work is still required to optimise and integrate tumour and plasma biomarkers to exploit the potential of these highly efficacious targeted agents.

Adoptive cell therapy in combination with checkpoint inhibitors in ovarian cancer

Immune therapy is a promising field within oncology but has been unsuccessful in ovarian cancer (OC). Still, there is rationale and evidence supporting immune therapy in OC. We investigated the potential for adoptive cell therapy (ACT) from in vitro expanded tumor-infiltrating lymphocytes (TILs) in combination with checkpoint inhibitors (ICI) and conducted immunological testing of ex vivo expanded TILs (REP-TILs).

Six patients with late-stage metastatic high-grade serous OC were treated with immune therapy consisting of ipilimumab followed by surgery to obtain TILs and infusion of REP-TILs, low-dose IL-2 and nivolumab.

One patient achieved a partial response and 5 others experienced disease stabilization for up to 12 months. Analysis of the REP-TILs with flow- and mass-cytometry show primarily activated and differentiated effector memory T cells. REP-TILs showed in vitro reactivity and expression of inhibitory receptors, such as LAG-3 and PD-1. Furthermore, our data indicate that addition of ipilimumab therapy improves the T cell fold expansion during production, increase the level of CD8 T cell tumor reactivity, and favorably affect the T cell phenotype.

We show that the combination of ICI and ACT is feasible and safe. With one partial response and one long-lasting SD, we demonstrated the potential of ACT in OC.

Safety, immunogenicity, and clinical efficacy of durvalumab in combination with folate receptor alpha vaccine TPIV200 in patients with advanced ovarian cancer: a phase II trial

BACKGROUND

Immune checkpoint inhibitors (ICIs) to date have demonstrated limited activity in advanced ovarian cancer (OC). Folate receptor alpha (FRα) is overexpressed in the majority of OCs and presents an attractive target for a combination immunotherapy to potentially overcome resistance to ICI in OCs. The current study sought to examine clinical and immunologic responses to TPIV200, a multiepitope FRα vaccine administered with programmed death ligand 1 (PD-L1) inhibitor durvalumab in patients with advanced platinum-resistant OC.

METHODS

Following Simon two-stage phase II trial design, 27 patients were enrolled. Treatment was administered in 28-day cycles (intradermal TPIV200 and granulocyte-macrophage colony-stimulating factor (GM-CSF) for 6 cycles and intravenous durvalumab for 12 cycles). Primary endpoints included overall response rate and progression-free survival at 24 weeks. Translational parameters focused on tumor microenvironment, PD-L1 and FRα expression, and peripheral vaccine-specific immune responses.

RESULTS

Treatment was well tolerated, with related grade 3 toxicity rate of 18.5%. Increased T cell responses to the majority of peptides were observed in all patients at 6 weeks (p<0.0001). There was one unconfirmed partial response (3.7%) and nine patients had stable disease (33.3%). Clinical benefit was not associated with baseline FRα or PD-L1 expression. One patient with prolonged clinical benefit demonstrated loss of FRα expression and upregulation of PD-L1 in a progressing lesion. Despite the low overall response rate, the median overall survival was 21 months (13.5-∞), with evidence of benefit from postimmunotherapy regimens.

CONCLUSIONS

Combination of TPIV200 and durvalumab was safe and elicited robust FRα-specific T cell responses in all patients. Unexpectedly durable survival in this heavily pretreated population highlights the need to investigate the impact of FRα vaccination on the OC biology post-treatment.

Clinical Implications of DNA Repair Defects in High-Grade Serous Ovarian Carcinomas

Despite significant improvements in surgical and medical management, high grade serous ovarian cancer (HGSOC) still represents the deadliest gynecologic malignancy and the fifth most frequent cause of cancer-related mortality in women in the USA. Since DNA repair alterations are regarded as the “the Achille’s heel” of HGSOC, both DNA homologous recombination and DNA mismatch repair deficiencies have been explored and targeted in epithelial ovarian cancers in the latest years. In this review, we aim at focusing on the therapeutic issues deriving from a faulty DNA repair machinery in epithelial ovarian cancers, starting from existing and well-established treatments and investigating new therapeutic approaches which could possibly improve ovarian cancer patients’ survival outcomes in the near future. In particular, we concentrate on the role of both Poly (ADP-ribose) Polymerase (PARP) inhibitors (PARPis) and immune checkpoint inhibitors in HGSOC, highlighting their activity in relation to BRCA1/2 mutational status and homologous recombination deficiency (HRD). We investigate the biological rationale supporting their use in the clinical setting, pointing at tracking their route from the laboratory bench to the patient’s bedside. Finally, we deal with the onset of mechanisms of primary and acquired resistance to PARPis, reporting the pioneering strategies aimed at converting homologous-recombination (HR) proficient tumors into homologous recombination (HR)-deficient HGSOC.

Prognostic significance of baseline T cells, B cells and neutrophil-lymphocyte ratio (NLR) in recurrent ovarian cancer treated with chemotherapy

PURPOSE

Biomarkers are needed to guide treatment decisions in recurrent ovarian cancer, as a high proportion of patients do not benefit from treatments. Data on immune subsets in patients receiving chemotherapy are scarce. We investigated the impact of T cells, B cells, neutrophils and the neutrophil-lymphocyte ratio (NLR) in ovarian cancer patients receiving palliative chemotherapy.

METHODS

Blood samples were collected prospectively at baseline in recurrent ovarian cancer (N = 72) receiving chemotherapy. T cells, B cells, neutrophils, and NLR were analyzed. Primary and secondary endpoints were overall survival (OS) and treatment response, respectively. Cut-offs for T and B cells were predefined.

RESULTS

In patients with low vs. high T and B cells counts, OS was 6.1 months vs 12.0 months (P = 0.017) and 6.1 months vs 12.0 months (P = 0.011, respectively. Low T and B cells analyzed as continuous variables were also associated with unfavorable OS, P = 0.011 and P = 0.007, respectively. Neutrophils had no significant prognostic impact. Median NLR was 4.1. High vs. low NLR was associated with poor survival, 7.4 months vs. 15.9 months (P = 0.012). In multivariate analysis including platinum sensitivity, number of prior lines of chemotherapy, and performance status, high NLR remained an independent poor prognostic factor HR: 2.17 (95% CI 1.21-3.88) (P = 0.009). High NLR was also significantly associated with lack of response, OR 0.15 (95% CI: 0.04-0.51) (P = 0.002).

CONCLUSION

In recurrent ovarian cancer patients undergoing palliative chemotherapy, low T and B lymphocyte counts had an unfavorable prognostic impact. High NLR was associated with lack of response and a poor prognosis, and the parameter may be used in patient counselling and treatment decisions.

A gene signature for immune subtyping of desert, excluded, and inflamed ovarian tumors

PROBLEM

The current tumor immunology paradigm emphasizes the role of the immune tumor microenvironment and distinguishes several histologically and transcriptionally different immune tumor subtypes. However, the experimental validation of such classification is so far limited to selected cancer types. Here, we aimed to explore the existence of inflamed, excluded, and desert immune subtypes in ovarian cancer, as well as investigate their association with the disease outcome.

METHOD OF STUDY

We used the publicly available ovarian cancer dataset from The Cancer Genome Atlas for developing subtype assignment algorithm, which was next verified in a cohort of 32 real-world patients of a known tumor subtype.

RESULTS

Using clinical and gene expression data of 489 ovarian cancer patients in the publicly available dataset, we identified three transcriptionally distinct clusters, representing inflamed, excluded, and desert subtypes. We developed a two-step subtyping algorithm with COL5A2 serving as a marker for separating excluded tumors, and CD2, TAP1, and ICOS for distinguishing between inflamed and desert tumors. The accuracy of gene expression-based subtyping algorithm in a real-world cohort was 75%. Additionally, we confirmed that patients bearing inflamed tumors are more likely to survive longer.

CONCLUSION

Our results highlight the presence of transcriptionally and histologically distinct immune subtypes among ovarian tumors and emphasize the potential benefit of immune subtyping as a clinical tool for treatment tailoring.

Triptolide prevents bone loss via suppressing osteoclastogenesis through inhibiting PI3K-AKT-NFATc1 pathway

Bone loss (osteopenia) is a common complication in human solid tumour. In addition, after surgical treatment of gynaecological tumour, osteoporosis often occurs due to the withdrawal of oestrogen. The major characteristic of osteoporosis is the low bone mass with micro-architectural deteriorated bone tissue. And the main cause is the overactivation of osteoclastogenesis, which is one of the most important therapeutic targets. Inflammation could induce the interaction of RANKL/RANK, which is the promoter of osteoclastogenesis. Triptolide is derived from the traditional Chinese herb lei gong teng, presented multiple biological effects, including anti-cancer, anti-inflammation and immunosuppression. We hypothesized that triptolide could inhibits osteoclastogenesis by suppressing inflammation activation. In this study, we confirmed that triptolide could suppress RANKL-induced osteoclastogenesis in bone marrow mononuclear cells (BMMCs) and RAW264.7 cells and inhibited the osteoclast bone resorption functions. PI3K-AKT-NFATc1 pathway is one of the most important downstream pathways of RANKL-induced osteogenesis. The experiments in vitro indicated that triptolide suppresses the activation of PI3K-AKT-NFATc1 pathway and the target point located at the upstream of AKT because both NFATc1 overexpression and AKT phosphorylation could ameliorate the triptolide suppression effects. The expression of MDM2 was elevated, which demonstrated the MDM-p53-induced cell death might contribute to the osteoclastogenesis suppression. Ovariectomy-induced bone loss and inflammation activation were also found to be ameliorated in the experiments in vivo. In summary, the new effect of anti-cancer drug triptolide was demonstrated to be anti-osteoclastogenesis, and we demonstrated triptolide might be a promising therapy for bone loss caused by tumour.

Randomized Phase II Trial of Nivolumab Versus Nivolumab and Ipilimumab for Recurrent or Persistent Ovarian Cancer: An NRG Oncology Study

PURPOSE

Single-agent PD-1 blockade exhibits limited efficacy in epithelial ovarian cancer (EOC). We evaluated ipilimumab plus nivolumab compared with nivolumab alone in women with persistent or recurrent EOC.

METHODS

Eligibility criteria included measurable disease, 1-3 prior regimens, and platinum-free interval (PFI) < 12 months. Participants were randomly allocated to intravenous nivolumab (every 2 weeks) or induction with nivolumab plus ipilimumab for 4 doses (every 3 weeks), followed by every-2-week maintenance nivolumab for a maximum of 42 doses. The primary null hypothesis was equal probability of objective response within 6 months of random allocation in each arm.

RESULTS

One hundred patients were allocated to receive either nivolumab (n = 49), or nivolumab plus ipilimumab (n = 51), with PFI of < 6 months in 62%. Six (12.2%) responses occurred within 6 months in the nivolumab group and 16 (31.4%) in the nivolumab plus ipilimumab group (odds ratio, 3.28; 85% CI, 1.54 to infinity; P = .034). The median progression-free survival (PFS) was 2 and 3.9 months in the nivolumab and nivolumab plus ipilimumab groups, respectively, with a PFI-stratified hazard ratio of 0.53 (95% CI, 0.34 to 0.82); the respective hazard ratio for death was 0.79 (95% CI, 0.44 to 1.42). Grade ≥ 3 related adverse events occurred in 33% of patients in the nivolumab group and 49% in the combination group, with no treatment-related deaths. PD-L1 expression was not significantly associated with response in either treatment group.

CONCLUSION

Compared with nivolumab alone, the combination of nivolumab and ipilimumab in EOC resulted in superior response rate and longer, albeit limited, PFS, with toxicity of the combination regimen comparable to prior reports. Additional combination studies to enhance durability of the dual regimen are warranted.

Pembrolizumab monotherapy in Japanese patients with advanced ovarian cancer: Subgroup analysis from the KEYNOTE-100

Interim results from the two-cohort, phase 2 KEYNOTE-100 study (NCT02674061) of 376 patients with previously treated advanced recurrent ovarian cancer (ROC) showed that pembrolizumab monotherapy was associated with an objective response rate (ORR) of 8.0% (95% CI, 5.4-11.2). We present outcomes for the Japanese patients (n = 21) enrolled in KEYNOTE-100. Patients with epithelial ROC had received either 1-3 prior chemotherapy lines and had platinum-free interval or treatment-free interval (PFI; TFI) of 3-12 months (cohort A) or 4-6 prior chemotherapy lines and had PFI/TFI of ≥3 months (cohort B). All patients received pembrolizumab 200 mg every 3 weeks as monotherapy for 2 years or until progression, death, unacceptable toxicity or consent withdrawal. Primary objectives were ORR per RECIST v1.1 for each cohort and higher programmed death ligand-1 (PD-L1) tumor expression. The relationship between PD-L1 expression (measured as combined positive score [CPS]) and ORR was assessed. Twenty-one Japanese patients (cohort A, n = 19; cohort B, n = 2) were treated. The median (range) age was 57 (37-78) years; 19 (90.5%) patients had ECOG status of 0 and 16 (76.2%) patients had stage III-IV disease. ORR was 19.0% (95% CI, 5.4-41.9) and seemed to increase with increasing PD-L1 expression. A total of 13 (61.9%) patients had treatment-related adverse events (TRAE), and 5 (23.8%) had grade 3-4 TRAE. There were no treatment-related deaths in this subpopulation. Pembrolizumab monotherapy was associated with antitumor activity in Japanese patients with ROC, with no new safety signals identified in this subpopulation. The data suggested a trend toward higher PD-L1 expression among some patients with higher ORR.

Combining novel agents with radiotherapy for gynecologic malignancies: beyond the era of cisplatin

Therapeutic strategies combining radiation therapy with novel agents have become an area of intense research focus in oncology and are actively being investigated for a wide range of solid tumors. The mechanism of action of these systemic agents can be stratified into three general categories: (1) enhancement or alteration of the immune system; (2) disruption of DNA damage response mechanisms; and (3) impediment of cellular signaling pathways involving growth, angiogenesis, and hypoxia. Pre-clinical data suggest that radiation therapy has immunogenic qualities and may optimize response to immuno-oncology therapies by priming the immune system, whereas other novel systemic agents can enhance radiosensitivity through augmentation of genomic instability and alteration of central signaling pathways related to growth and survival. Gynecologic cancers in particular have the potential for synergistic response to combination approaches incorporating radiation therapy and novel systemic therapies. Several clinical trials have been proposed to elucidate the efficacy and safety of such approaches. Here we discuss the mechanisms of novel therapies and the rationale for these combination strategies, reviewing the relevant pre-clinical and clinical data. We explore their optimal use with respect to indications, interactions, and potential synergy in combination with radiation therapy and review ongoing trials and active areas of investigation.

Lymphocytic infiltration and Chemotherapy Response Score as prognostic markers in ovarian cancer patients treated with Neoadjuvant chemotherapy

Neoadjuvant Chemotherapy (NACT) followed by Interval Debulking Surgery (IDS) is an accepted frontline treatment in patients with advanced Epithelial Ovarian Cancer (EOC). Histopathologic assessment of tumor post NACT may provide a surrogate for response to treatment. The present study aims to characterize the pathological response and to examine its prognostic significance in these patients. Medical records of women with EOC treated in our institution from 2011 to 2016 were retrospectively identified. IDS specimens were reviewed by study pathologist and Chemotherapy Response Score (CRS), lymphocytic infiltration, necrosis and mitosis were assessed. 55 patients with EOC treated with NACT were identified and 48 had complete clinical and pathological data. Median age was 63 years. CRS assessed at omentum predicted PFS when adjusted for age, stage, debulking status (complete, optimal, suboptimal) and post IDS bevacizumab administration (mPFS CRS 1 vs 2 vs 3: 10.3-14-18.7 months 95% CI [7.4-15.7], [12.2-22.9], [13.5-31.3]). Presence of lymphocytic infiltration was associated with improved OS (log-rank test P = 0.015). Post IDS bevacizumab was associated with shorter PFS in patients with lymphocytic infiltration. BRCA status was known for 25 patients and presence of BRCA1/2 mutations was strongly correlated with lymphocytic infiltration (P = 0.011) but not CRS omentum (P = 0.926). Our study confirms the predictive value of CRS in EOC patients treated with NACT and IDS, but also demonstrates the prognostic significance of lymphocytic infiltration as well as its possible interaction with bevacizumab treatment.

Immune Checkpoint Inhibitors in Epithelial Ovarian Cancer: An Overview on Efficacy and Future Perspectives

Epithelial ovarian cancer (EOC) is the leading cause of death among gynecological cancers. Despite improvements in medical treatments, the prognosis for EOC remains poor, and there is an urgent need for new therapeutic strategies. Immune checkpoint inhibitors (CPIs) have dramatically improved survival of several cancers and are under evaluation in OC. Unfortunately, CPIs have shown globally unsatisfactory results. The aim of this manuscript is to critically review the results from early-phase trials with CPIs in terms of safety and activity, discuss the possible reasons for disappointing results and the new therapeutic approaches to improve patient outcomes.

Immunotherapy for Gynecologic Cancer: Current Applications and Future Directions

The role of the immune system in the development of cancer has been a subject of ongoing clinical investigation in recent years. Emerging data demonstrate that tumorigenesis resulting in ovarian, uterine, and cervical cancers is a consequence of impaired host immune responses to cancerous cells. Leveraging the immune system through the use of immune checkpoint inhibitors, therapeutic vaccine therapy, and adoptive cell transfer presents a profound opportunity to revolutionize cancer treatment. This review will encompass the role of the immune system in development of gynecologic cancers and highlight recent data regarding immunotherapy applications in ovarian, uterine, and cervical cancers.

Combining DNMT and HDAC6 inhibitors increases anti-tumor immune signaling and decreases tumor burden in ovarian cancer

Novel therapies are urgently needed for ovarian cancer, the deadliest gynecologic malignancy. Ovarian cancer has thus far been refractory to immunotherapies that stimulate the host immune system to recognize and kill cancer cells. This may be because of a suppressive tumor immune microenvironment and lack of recruitment and activation of immune cells that kill cancer cells. Our previous work showed that epigenetic drugs including DNA methyltransferase inhibitors and histone deacetylase 6 inhibitors (DNMTis and HDAC6is) individually increase immune signaling in cancer cells. We find that combining DNMTi and HDAC6i results in an amplified type I interferon response, leading to increased cytokine and chemokine expression and higher expression of the MHC I antigen presentation complex in human and mouse ovarian cancer cell lines. Treating mice bearing ID8 Trp53-/- ovarian cancer with HDAC6i/DNMTi led to an increase in tumor-killing cells such as IFNg+ CD8, NK, and NKT cells and a reversal of the immunosuppressive tumor microenvironment with a decrease in MDSCs and PD-1hi CD4 T cells, corresponding with an increase in survival. Thus combining the epigenetic modulators DNMTi and HDAC6i increases anti-tumor immune signaling from cancer cells and has beneficial effects on the ovarian tumor immune microenvironment.

Improving cancer immunotherapy using nanomedicines: progress, opportunities and challenges

Multiple nanotherapeutics have been approved for patients with cancer, but their effects on survival have been modest and, in some examples, less than those of other approved therapies. At the same time, the clinical successes achieved with immunotherapy have revolutionized the treatment of multiple advanced-stage malignancies. However, the majority of patients do not benefit from the currently available immunotherapies and many develop immune-related adverse events. By contrast, nanomedicines can reduce - but do not eliminate - the risk of certain life-threatening toxicities. Thus, the combination of these therapeutic classes is of intense research interest. The tumour microenvironment (TME) is a major cause of the failure of both nanomedicines and immunotherapies that not only limits delivery, but also can compromise efficacy, even when agents accumulate in the TME. Coincidentally, the same TME features that impair nanomedicine delivery can also cause immunosuppression. In this Perspective, we describe TME normalization strategies that have the potential to simultaneously promote the delivery of nanomedicines and reduce immunosuppression in the TME. Then, we discuss the potential of a combined nanomedicine-based TME normalization and immunotherapeutic strategy designed to overcome each step of the cancer-immunity cycle and propose a broadly applicable 'minimal combination' of therapies designed to increase the number of patients with cancer who are able to benefit from immunotherapy.

Optimizing immunotherapy for gynecologic cancers

PURPOSE OF REVIEW

This review will provide an update on the most recent clinical developments in immuno-oncology in advanced gynecologic cancers and will also highlight ongoing studies in this field.

RECENT FINDINGS

Although immune checkpoint blockade (ICB) therapy is rapidly altering the treatment landscape in a myriad of solid tumors, the efficacy of ICB therapy with antibodies directed against CTLA-4, PD-1, and PD-L1 in advanced gynecologic cancers has been limited. The exception has been the PD-1 inhibitor pembrolizumab in microsatellite instability high (MSI-H) or mismatch repair-deficient (dMMR) advanced endometrial cancers, highlighted by the recent conditional approval of pembrolizumab in recurrent/metastatic PD-L1-positive cervical cancers and the accelerated approval of pembrolizumab and lenvatinib in microsatellite stable (MSS) or mismatch repair-proficient (pMMR) advanced endometrial cancer. The discovery of novel, rational ICB combinatorial approaches in advanced gynecologic cancers is highly warranted.

SUMMARY

Recent advances in the genomic characterization of gynecologic malignancies have informed clinical trial design. However, improved molecular and immunophenotypic biomarkers to more accurately identify patients who will most benefit from immunotherapeutic approaches are urgently needed. This is especially critical as we attempt to integrate immune-oncology agents, chemotherapy, targeted therapy, and radiation therapy in the management of gynecologic cancers.