A phase 1b study of intraperitoneal oncolytic viral immunotherapy in platinum-resistant or refractory ovarian cancer.

OBJECTIVE: Our objective was to assess safety and adverse events associated with intraperitoneal Olvi-Vec virotherapy in patients with platinum-resistant or refractory ovarian cancer (PRROC). Secondary objectives included objective response rate (ORR) per RECIST 1.1 and progression-free survival (PFS). METHODS: Olvi-Vec is a modified vaccinia virus that causes oncolysis and immune activation. An open-label phase 1b trial using a 3 + 3 dose escalation was conducted. Intraperitoneal Olvi-Vec was given as monotherapy in two consecutive daily doses. Translational analyses included anti-virus antibody levels, viral shedding, circulating tumor cells (CTCs) and T cells. RESULTS: Twelve patients (median age: 69 years, range: 45-77) with median 5 prior therapies (range: 2-10) and 2 prior platinum lines (range: 1-5) were enrolled. There were three dose level cohorts: 3 × 109 (n = 6), 1 × 1010 (n = 5), and 2.5 × 1010 (n = 1) plaque forming units (PFU)/day on two consecutive days. Treatment-related adverse events (TRAEs) included G1/G2 nausea (n = 6), fever (n = 6), abdominal distention (n = 5), and abdominal pain (n = 4). There were no Grade 4 TRAEs, no dose relationship to TRAEs, and no deaths attributed to Olvi-Vec. The ORR was 9% (1/11). Stable disease (SD) was 64% (7/11), and SD ≥15 weeks was 46% (5/11). Median PFS was 15.7 weeks (95%CI: 5.7-34.5), including extended PFS in four patients (23.2, 34.5, 59.4+ and 70.8 weeks). Three patients had extended overall survival (deceased 33.6 months, and alive with disease at 54 and 59 months). CTCs diminished in 6/8 (75%) baseline-positive patients. Immune activation was demonstrated from virus-enhanced tumor infiltration of CD8+ T-cells and activation of tumor-specific T-cells in peripheral blood. CONCLUSIONS: Oncolytic viral therapy with intraperitoneal Olvi-Vec showed promising safety, clinical activities, and immune activation in patients with PRROC, warranting further clinical investigation.

Chlamydia trachomatis, Pelvic Inflammatory Disease, and Epithelial Ovarian Cancer.

Epidemiologic, clinical, molecular and translational research findings support an interrelationship between Chlamydia trachomatis, pelvic inflammatory disease (PID), and epithelial ovarian cancer (EOC). Overall, the link between C. trachomatis, PID, and EOC seems to be relatively weak, although nondifferential misclassification bias may have attenuated the results. The predominant tubal origin of EOC and the role of chronic inflammation in tumorigenesis suggest that the association is biologically plausible. Thus, C. trachomatis and PID may represent potential risk factors or risk markers for EOC. However, many steps in this chain of events are still poorly understood and need to be addressed in future studies. Research gaps include time of exposure in relation to the long-term consequences and lag time to EOC. Data of differential risk for EOC between chlamydial and nonchlamydial PID is also needed. Another major research gap has been the absence of high-performance biomarkers for C. trachomatis, PID, and EOC, as well as EOC precursors. Biomarkers for C. trachomatis and PID leading to increased risk of EOC should be developed. If the association is confirmed, C. trachomatis and PID prevention efforts may play a role in reducing the burden of EOC.

Human papillomavirus infection: Is it associated with epithelial ovarian cancer?

PURPOSE: Human papillomavirus (HPV), the causative agent of cervical cancer, is associated with several other epithelial malignancies. Previous reports on HPV infection and its association with ovarian cancer are highly contradicting. Reports on HPV association with ovarian cancer in Indian women are also rare. Hence, the purpose of this study was to screen women with serous epithelial ovarian cancer for possible HPV infection. METHODS: Tumor samples, collected at the time of surgery from 88 women with serous epithelial ovarian cancer were screened using a specific and sensitive PCR. The PCR results were confirmed with Southern blotting using HPV genome-specific probes, both of high-risk HPV type 16 and 18 and low-risk HPV type 6 and 11. All the samples were again tested for another 14 high-risk HPV genotypes with a commercially available qRT-PCR. RESULTS: All the samples screened and confirmed by various tests did not show presence of either low-risk or high-risk HPV DNA, indicating the absence of HPV infections in these ovarian cancer tissues. CONCLUSIONS: The present study shows that HPV infection may not be associated with epithelial ovarian cancer. The result of the current investigation strongly supports the results of earlier research that, HPV is not associated with ovarian cancer.

Anti-tumor effect of a dual cancer-specific recombinant adenovirus on ovarian cancer cells.

BACKGROUND: Apoptin can specifically kill cancer cells but has no toxicity to normal cells. Human telomerase reverse transcriptase (hTERT) acts as a tumor-specific promoter, triggering certain genes to replicate or express only in tumor cells, conferring specific replication and killing abilities. This study aimed at investigating the anticancer potential of the recombinant adenovirus Ad-apoptin-hTERTp-E1a (Ad-VT) in ovarian cancer treatment. METHODS: Crystal Violet staining and WST-1 assays were used to analyze the inhibitory effect of Ad-VT on ovarian cancer SKOV3 and OVCAR-3 cells. Ad-VT-induced apoptosis of ovarian cancer cells, was detected using Hoechst, Annexin V-FITC/PI, JC-1 staining. Cell migration and invasion of ovarian cancer cells were detected using cell-scratch and Transwell assays. The pGL4.51 plasmid was used to transfect and to generate SKOV3-LUC cells, that stably express luciferase. The in vivo tumor inhibition effect of Ad-VT was subsequently confirmed using a tumor-bearing nude mouse model. RESULTS: Ad-VT had a strong apoptosis-inducing effect on SKOV3 and OVCAR-3 cells, that was mainly mediated through the mitochondrial apoptotic pathway. The Ad-VT could significantly increase the inhibition of ovarian cancer cell migration and invasion. The Ad-VT also can inhibit tumor growth and reduce toxicity in vivo. CONCLUSIONS: The recombinant adenovirus, comprising the apoptin protein and the hTERTp promoter, was able to inhibit the growth of ovarian cancer cells and promote their apoptosis.

Serologic markers of Chlamydia trachomatis and other sexually transmitted infections and subsequent ovarian cancer risk: Results from the EPIC cohort.

A substantial proportion of epithelial ovarian cancer (EOC) arises in the fallopian tube and other epithelia of the upper genital tract; these epithelia may incur damage and neoplastic transformation after sexually transmitted infections (STI) and pelvic inflammatory disease. We investigated the hypothesis that past STI infection, particularly Chlamydia trachomatis, is associated with higher EOC risk in a nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort including 791 cases and 1669 matched controls. Serum antibodies against C. trachomatis, Mycoplasma genitalium, herpes simplex virus type 2 (HSV-2) and human papillomavirus (HPV) 16, 18 and 45 were assessed using multiplex fluorescent bead-based serology. Conditional logistic regression was used to estimate relative risks (RR) and 95% confidence intervals (CI) comparing women with positive vs. negative serology. A total of 40% of the study population was seropositive to at least one STI. Positive serology to C. trachomatis Pgp3 antibodies was not associated with EOC risk overall, but with higher risk of the mucinous histotype (RR = 2.30 [95% CI = 1.22-4.32]). Positive serology for chlamydia heat shock protein 60 (cHSP60-1) was associated with higher risk of EOC overall (1.36 [1.13-1.64]) and with the serous subtype (1.44 [1.12-1.85]). None of the other evaluated STIs were associated with EOC risk overall; however, HSV-2 was associated with higher risk of endometrioid EOC (2.35 [1.24-4.43]). The findings of our study suggest a potential role of C. trachomatis in the carcinogenesis of serous and mucinous EOC, while HSV-2 might promote the development of endometrioid disease.

Detection and genotyping of CMV and HPV in tumors and fallopian tubes from epithelial ovarian cancer patients.

Viral and bacterial infections are detected in epithelial ovarian cancer (EOC) tissues. Since the fallopian tubes are often affected by pelvic inflammatory disease (PID) and the majority of serous EOCs appear to originate from dysplastic lesions in the distal tube, it is relevant to consider the potential role that infectious agents may play in ovarian carcinogenesis. We sought to analyze the prevalence of human papillomavirus (HPV) and cytomegalovirus (CMV) in EOC tissue and fallopian tube specimens obtained at tumor resection. Ovarian cancer and fallopian tube tissue samples obtained from patients with EOC were analyzed by both qualitative and quantitative PCR to detect and quantify viral DNA. The presence of CMV and HPV DNA was detected in 70% and 74% cancerous ovarian tissues, respectively, and was significantly higher in EOC than in benign tumor cases (P ≤ 0.01). CMV or HPV infection was observed also in the fallopian tube samples. Infection with HPV16 was determined in 70% of EOC cases. Almost two thirds of EOC patients demonstrated coinfection with CMV and HPV in the pathological samples. The results revealed that the presence of CMV and HPV in EOC samples is common. CMV and HPV infections can be potential risks for EOC development.

Sexually transmitted infections and risk of epithelial ovarian cancer: results from the Nurses' Health Studies.

BACKGROUND: Sexually transmitted infections (STIs) are associated with pelvic inflammatory disease and tubal pathologies. Given the tubal origin of a proportion of ovarian cancers, STIs may be relevant in their aetiology. METHODS: Antibodies indicating past infection with Chlamydia trachomatis, Mycoplasma genitalium, herpes simplex virus type 2, and against human papillomavirus oncogenes (L1 and E6+E7 oncoproteins of types 16, 18, 45) were measured in prediagnosis plasma samples in a nested case-control study in the Nurses' Health Studies (n = 337 cases 1:1 matched to controls). Logistic regression was used to estimate multivariable-adjusted relative risks (RRs) and 95% confidence intervals [CIs] comparing women seropositive vs. seronegative among all cases (invasive and borderline), invasive (n = 257), and invasive serous ovarian cancers; n = 170), and borderline ovarian tumours (n = 80). RESULTS: C. trachomatis seropositivity was associated with higher risk of ovarian cancer overall (RR = 2.07 [1.25-3.43]); results were similar for invasive, invasive serous, and borderline tumours. We observed no associations for the other STIs. Relative to women seronegative to all infections, strongest associations were observed for seropositivity to C. trachomatis plus another STI (2.74 [1.20-6.27]; C. trachomatis alone, 1.88 [1.03-3.42]; all cases); however, the RRs were not significantly different. CONCLUSIONS: C. trachomatis infection may increase ovarian cancer risk; additional studies are required.

Antagonism of Glycolysis and Reductive Carboxylation of Glutamine Potentiates Activity of Oncolytic Adenoviruses in Cancer Cells.

Tumor cells exhibiting the Warburg effect rely on aerobic glycolysis for ATP production and have a notable addiction to anaplerotic use of glutamine for macromolecular synthesis. This strategy maximizes cellular biosynthetic potential while avoiding excessive depletion of NAD+ and provides an attractive anabolic environment for viral infection. Here, we evaluate infection of highly permissive and poorly permissive cancer cells with wild-type adenoviruses and the oncolytic chimeric adenovirus enadenotucirev (EnAd). All adenoviruses caused an increase in glucose and glutamine uptake along with increased lactic acid secretion. Counterintuitively, restricting glycolysis using 2-deoxyglucose or by limiting glucose supply strongly improved virus activity in both cell types. Antagonism of glycolysis also boosted EnAd replication and transgene expression within human tumor biopsies and in xenografted tumors in vivo. In contrast, the virus life cycle was critically dependent on exogenous glutamine. Virus activity in glutamine-free cells was rescued with exogenous membrane-permeable α-ketoglutarate, but not pyruvate or oxaloacetate, suggesting an important role for reductive carboxylation in glutamine usage, perhaps for production of biosynthetic intermediates. This overlap between the metabolic phenotypes of adenovirus infection and transformed tumor cells may provide insight into how oncolytic adenoviruses exploit metabolic transformation to augment their selectivity for cancer cells. SIGNIFICANCE: This study describes changes in glucose and glutamine metabolism induced by oncolytic and wild-type adenoviruses in cancer cells, which will be important to consider in the preclinical evaluation of oncolytic viruses.

Ad5NULL-A20: A Tropism-Modified, αvß6 Integrin-Selective Oncolytic Adenovirus for Epithelial Ovarian Cancer Therapies.

Purpose: Virotherapies are maturing in the clinical setting. Adenoviruses (Ad) are excellent vectors for the manipulability and tolerance of transgenes. Poor tumor selectivity, off-target sequestration, and immune inactivation hamper clinical efficacy. We sought to completely redesign Ad5 into a refined, tumor-selective virotherapy targeted to αvß6 integrin, which is expressed in a range of aggressively transformed epithelial cancers but nondetectable in healthy tissues.Experimental Design: Ad5NULL-A20 harbors mutations in each major capsid protein to preclude uptake via all native pathways. Tumor-tropism via αvß6 targeting was achieved by genetic insertion of A20 peptide (NAVPNLRGDLQVLAQKVART) within the fiber knob protein. The vector's selectivity in vitro and in vivo was assessed.Results: The tropism-ablating triple mutation completely blocked all native cell entry pathways of Ad5NULL-A20 via coxsackie and adenovirus receptor (CAR), αvß3/5 integrins, and coagulation factor 10 (FX). Ad5NULL-A20 efficiently and selectively transduced αvß6+ cell lines and primary clinical ascites-derived EOC ex vivo, including in the presence of preexisting anti-Ad5 immunity. In vivo biodistribution of Ad5NULL-A20 following systemic delivery in non-tumor-bearing mice was significantly reduced in all off-target organs, including a remarkable 107-fold reduced genome accumulation in the liver compared with Ad5. Tumor uptake, transgene expression, and efficacy were confirmed in a peritoneal SKOV3 xenograft model of human EOC, where oncolytic Ad5NULL-A20-treated animals demonstrated significantly improved survival compared with those treated with oncolytic Ad5.Conclusions: Oncolytic Ad5NULL-A20 virotherapies represent an excellent vector for local and systemic targeting of αvß6-overexpressing cancers and exciting platforms for tumor-selective overexpression of therapeutic anticancer modalities, including immune checkpoint inhibitors. Clin Cancer Res; 24(17); 4215-24. ©2018 AACR.