Molecular Circuits of Immune Sensing and Response to Oncolytic Virotherapy.

Oncolytic virotherapy is a promising immunotherapy approach for cancer treatment that utilizes viruses to preferentially infect and eliminate cancer cells while stimulating the immune response. In this review, we synthesize the current literature on the molecular circuits of immune sensing and response to oncolytic virotherapy, focusing on viral DNA or RNA sensing by infected cells, cytokine and danger-associated-signal sensing by neighboring cells, and the subsequent downstream activation of immune pathways. These sequential sense-and-response mechanisms involve the triggering of molecular sensors by viruses or infected cells to activate transcription factors and related genes for a breadth of immune responses. We describe how the molecular signals induced in the tumor upon virotherapy can trigger diverse immune signaling pathways, activating both antigen-presenting-cell-based innate and T cell-based adaptive immune responses. Insights into these complex mechanisms provide valuable knowledge for enhancing oncolytic virotherapy strategies.

Strategies to reprogram anti-inflammatory macrophages towards pro-inflammatory macrophages to support cancer immunotherapies.

Tumor-associated myeloid cells, including macrophages and myeloid-derived suppressor cells, can be highly prevalent in solid tumors and play a significant role in the development of the tumor. Therefore, myeloid cells are being considered potential targets for cancer immunotherapies. In this review, we focused on strategies aimed at targeting tumor-associated macrophages (TAMs). Most strategies were studied preclinically but we also included a limited number of clinical studies based on these strategies. We describe possible underlying mechanisms and discuss future challenges and prospects.

Oncolytic alphavirus replicons mediated recruitment and activation of T cells.

Oncolytic viruses show promise in enhancing tumor immunogenicity by releasing immunogenic signals during tumor cell infection and lysis. In this study, we improved the virus-induced tumor immunogenicity of recombinant Semliki Forest virus (rSFV)-based replicon particles by encoding immunogenic cytokines such as C-X-C motif chemokine ligand 10 (CXCL10), FMS-like tyrosine kinase 3 ligand (Flt3L), or interferon-gamma (IFN-Æ´). Real-time imaging and flow cytometry of human cancer cell-based monolayer and spheroid cultures, using LNCaP or PANC-1 cells, revealed effective infection and transgene expression in both models. LNCaP cells exhibited higher and earlier rSFV infection compared to PANC-1 cells. While infected LNCaP cells effectively triggered immune recruitment and T cell activation even without encoding cytokines, PANC-1 cells demonstrated improved immune responses only when infected with replicons encoding cytokines, particularly IFN-Æ´, which enhanced tumor immunogenicity irrespective of cancer cell susceptibility to infection. Our study demonstrates that despite innate phenotypic disparities in cancer cells, rSFV-based replicons encoding cytokines can potentially generate effective immune responses in the tumor.

Histone Deacetylase 3-Directed PROTACs Have Anti-inflammatory Potential by Blocking Polarization of M0-like into M1-like Macrophages.

Macrophage polarization plays a crucial role in inflammatory processes. The histone deacetylase 3 (HDAC3) has a deacetylase-independent function that can activate pro-inflammatory gene expression in lipopolysaccharide-stimulated M1-like macrophages and cannot be blocked by traditional small-molecule HDAC3 inhibitors. Here we employed the proteolysis targeting chimera (PROTAC) technology to target the deacetylase-independent function of HDAC3. We developed a potent and selective HDAC3-directed PROTAC, P7, which induces nearly complete HDAC3 degradation at low micromolar concentrations in both THP-1 cells and human primary macrophages. P7 increases the anti-inflammatory cytokine secretion in THP-1-derived M1-like macrophages. Importantly, P7 decreases the secretion of pro-inflammatory cytokines in M1-like macrophages derived from human primary macrophages. This can be explained by the observed inhibition of macrophage polarization from M0-like into M1-like macrophage. In conclusion, we demonstrate that the HDAC3-directed PROTAC P7 has anti-inflammatory activity and blocks macrophage polarization, demonstrating that this molecular mechanism can be targeted with small molecule therapeutics.

Modelling the spatial dynamics of oncolytic virotherapy in the presence of virus-resistant tumour cells.

Oncolytic virotherapy is a promising form of cancer treatment that uses native or genetically engineered viruses to target, infect and kill cancer cells. Unfortunately, this form of therapy is not effective in a substantial proportion of cancer patients, partly due to the occurrence of infection-resistant tumour cells. To shed new light on the mechanisms underlying therapeutic failure and to discover strategies that improve therapeutic efficacy we designed a cell-based model of viral infection. The model allows us to investigate the dynamics of infection-sensitive and infection-resistant cells in tumour tissue in presence of the virus. To reflect the importance of the spatial configuration of the tumour on the efficacy of virotherapy, we compare three variants of the model: two 2D models of a monolayer of tumour cells and a 3D model. In all model variants, we systematically investigate how the therapeutic outcome is affected by the properties of the virus (e.g. the rate of viral spread), the tumour (e.g. production rate of resistant cells, cost of resistance), the healthy stromal cells (e.g. degree of resistance to the virus) and the timing of treatment. We find that various therapeutic outcomes are possible when resistant cancer cells arise at low frequency in the tumour. These outcomes depend in an intricate but predictable way on the death rate of infected cells, where faster death leads to rapid virus clearance and cancer persistence. Our simulations reveal three different causes of therapy failure: rapid clearance of the virus, rapid selection of resistant cancer cells, and a low rate of viral spread due to the presence of infection-resistant healthy cells. Our models suggest that improved therapeutic efficacy can be achieved by sensitizing healthy stromal cells to infection, although this remedy has to be weighed against the toxicity induced in the healthy tissue.

The combined signatures of hypoxia and cellular landscape provides a prognostic and therapeutic biomarker in hepatitis B virus-related hepatocellular carcinoma.

Prognosis and treatment options of hepatitis B virus-related hepatocellular carcinoma (HBV-HCC) are generally based on tumor burden and liver function. Yet, tumor growth and therapeutic resistance of HBV-HCC are strongly influenced by intratumoral hypoxia and cells infiltrating the tumor microenvironment (TME). We, therefore, studied whether linking parameters associated with hypoxia and TME cells could have a better prediction of prognosis and therapeutic responses. Quantification of 109 hypoxia-related genes and 64 TME cells was performed in 452 HBV-HCC tumors. Prognostic hypoxia and TME cells signatures were determined based on Cox regression and meta-analysis for generating the Hypoxia-TME classifier. Thereafter, the prognosis, tumor, and immune characteristics as well as the benefit of therapies in Hypoxia-TME defined subgroups were analyzed. Patients in the Hypoxialow /TMEhigh subgroup showed a better prognosis and therapeutic responses than any other subgroups, which can be well elucidated based on the differences in terms of immune-related molecules, tumor somatic mutations, and cancer cellular signaling pathways. Notably, our analysis furthermore demonstrated the synergistic influence of hypoxia and TME on tumor metabolism and proliferation. Besides, the classifier allowed a further subdivision of patients with early- and late-HCC stages. In addition, the Hypoxia-TME classifier was validated in another independent HBV-HCC cohort (n = 144) and several pan-cancer cohorts. Overall, the Hypoxia-TME classifier showed a pretreatment predictive value for prognosis and therapeutic responses, which might provide new directions for strategizing patients with optimal therapies.

A systematic analysis on the clinical safety and efficacy of onco-virotherapy.

Several onco-virotherapy candidates have been developed and clinically evaluated for the treatment of cancer, and several are approved for clinical use. In this systematic review we explored the clinical impact of onco-virotherapy compared to other cancer therapies by analyzing factors such as trial design, patient background, therapy design, delivery strategies, and study outcomes. For this purpose, we retrieved clinical studies from three platforms: ClinicalTrials.gov, PubMed, and EMBASE. We found that most studies were performed in patients with advanced and metastatic tumors, using a broad range of genetically engineered vectors and mainly administered intratumorally. Therapeutic safety was the most frequently assessed outcome, while relatively few studies focused on immunological antitumor responses. Moreover, only 59 out of 896 clinical studies were randomized controlled trials reporting comparative data. This systemic review thus reveals the need of more, and better controlled, clinical studies to increase our understanding on the application of onco-virotherapy either as a single treatment or in combination with other cancer immunotherapies.

Resistance Mechanisms Influencing Oncolytic Virotherapy, a Systematic Analysis.

Resistance to therapy is a frequently observed phenomenon in the treatment of cancer, and as with other cancer therapeutics, therapies based on oncolytic viruses also face the challenges of resistance, such as humoral and cellular antiviral responses, and tumor-associated interferon-mediated resistance. In order to identify additional mechanisms of resistance that may contribute to therapeutic failure, we developed a systematic search strategy for studies published in PubMed. We analyzed 6143 articles on oncolytic virotherapy and found that approximately 8% of these articles use resistance terms in the abstract and/or title. Of these 439 articles, 87 were original research. Most of the findings reported pertain to resistance mediated by tumor-cell-dependent interferon signaling. Yet, mechanisms such as epigenetic modifications, hypoxia-mediated inhibition, APOBEC-mediated resistance, virus entry barriers, and spatiotemporal restriction to viral spread, although not frequently assessed, were demonstrated to play a major role in resistance. Similarly, our results suggest that the stromal compartment consisting of, but not limited to, myeloid cells, fibroblasts, and epithelial cells requires more study in relation to therapy resistance using oncolytic viruses. Thus, our findings emphasize the need to assess the stromal compartment and to identify novel mechanisms that play an important role in conferring resistance to oncolytic virotherapy.

Re-polarization of immunosuppressive macrophages to tumor-cytotoxic macrophages by repurposed metabolic drugs.

M2-like tumor-associated macrophages promote tumor progression by establishing an immunosuppressive tumor microenvironment. The phenotype and activity of immunosuppressive macrophages are related to their mitochondrial metabolism. Thus, we studied if drugs targeting mitochondrial metabolic pathways can repolarize macrophages from M2 into an M1-like phenotype or can prevent M0-to-M2 polarization. The drugs selected are clinically approved or in clinical trials and target M2-specific metabolic pathways: fatty acid oxidation (Perhexiline and Trimetazidine), glutaminolysis (CB-839), PPAR activation (HX531), and mitochondrial electron transport chain (VLX-600). Murine bone marrow-derived macrophages were either polarized to M2 using IL-4 in the presence of the drugs or polarized first into M2 and then treated with the drugs in presence of IFN-γ for re-polarization. Targeting both fatty acid oxidation with Perhexiline or the electron transport chain with VLX-600 in the presence of IFN-γ, impaired mitochondrial basal, and maximal respiration and resulted in M2 to M1-like re-polarization (increased iNOS expression, NO production, IL-23, IL-27, and TNF-α secretion), similar to LPS+IFN-γ re-polarization. Moreover, drug-induced macrophage re-polarization resulted in a strong tumor-cytotoxic activity. Furthermore, the polarization of M0- to M2-like macrophages was impaired by CB-839, Trimetazidine, HX531, and Perhexiline, while Hx531 and Perhexiline also reduced MCP-1 secretion. Our results show that by targeting cell metabolism, macrophages could be re-polarized from M2- into an anti-tumoral M1-like phenotype and that M0-to-M2 polarization could be prevented. Overall, this study provides rational for the use of clinically applicable drugs to change an immunosuppressive tumor environment into a pro-inflammatory tumor environment that could support cancer immunotherapies.

First-in-Human Phase I Clinical Trial of an SFV-Based RNA Replicon Cancer Vaccine against HPV-Induced Cancers.

A first-in-human phase I trial of Vvax001, an alphavirus-based therapeutic cancer vaccine against human papillomavirus (HPV)-induced cancers was performed assessing immunological activity, safety, and tolerability. Vvax001 consists of replication-incompetent Semliki Forest virus replicon particles encoding HPV16-derived antigens E6 and E7. Twelve participants with a history of cervical intraepithelial neoplasia were included. Four cohorts of three participants were treated per dose level, ranging from 5 × 105 to 2.5 × 108 infectious particles per immunization. The participants received three immunizations with a 3-week interval. For immune monitoring, blood was drawn before immunization and 1 week after the second and third immunization. Immunization with Vvax001 was safe and well tolerated, with only mild injection site reactions, and resulted in both CD4+ and CD8+ T cell responses against E6 and E7 antigens. Even the lowest dose of 5 × 105 infectious particles elicited E6/E7-specific interferon (IFN)-γ responses in all three participants in this cohort. Overall, immunization resulted in positive vaccine-induced immune responses in 12 of 12 participants in one or more assays performed. In conclusion, Vvax001 was safe and induced immune responses in all participants. These data strongly support further clinical evaluation of Vvax001 as a therapeutic vaccine in patients with HPV-related malignancies.

Therapeutic Vaccines and Cancer Immunotherapy.

Cancer immunotherapy and immunization are the next steps towards safe and effective cancer treatment [...].

Hepatitis C Virus Proteins Core and NS5A Are Highly Sensitive to Oxidative Stress-Induced Degradation after eIF2α/ATF4 Pathway Activation.

Hepatitis C virus (HCV) infection is accompanied by increased oxidative stress and endoplasmic reticulum stress as a consequence of viral replication, production of viral proteins, and pro-inflammatory signals. To overcome the cellular stress, hepatocytes have developed several adaptive mechanisms like anti-oxidant response, activation of Unfolded Protein Response and autophagy to achieve cell survival. These adaptive mechanisms could both improve or inhibit viral replication, however, little is known in this regard. In this study, we investigate the mechanisms by which hepatocyte-like (Huh7) cells adapt to cellular stress in the context of HCV protein overexpression and oxidative stress. Huh7 cells stably expressing individual HCV (Core, NS3/4A and NS5A) proteins were treated with the superoxide anion donor menadione to induce oxidative stress. Production of reactive oxygen species and activation of caspase 3 were quantified. The activation of the eIF2α/ATF4 pathway and changes in the steady state levels of the autophagy-related proteins LC3 and p62 were determined either by quantitative polymerase chain reaction (qPCR) or Western blotting. Huh7 cells expressing Core or NS5A demonstrated reduced oxidative stress and apoptosis. In addition, phosphorylation of eIF2α and increased ATF4 and CHOP expression was observed with subsequent HCV Core and NS5A protein degradation. In line with these results, in liver biopsies from patients with hepatitis C, the expression of ATF4 and CHOP was confirmed. HCV Core and NS5A protein degradation was reversed by antioxidant treatment or silencing of the autophagy adaptor protein p62. We demonstrated that hepatocyte-like cells expressing HCV proteins and additionally exposed to oxidative stress adapt to cellular stress through eIF2a/ATF4 activation and selective degradation of HCV pro-oxidant proteins Core and NS5A. This selective degradation is dependent on p62 and results in increased resistance to apoptotic cell death induced by oxidative stress. This mechanism may provide a new key for the study of HCV pathology and lead to novel clinically applicable therapeutic interventions.

GMP manufacturing of Vvax001, a therapeutic anti-HPV vaccine based on recombinant viral particles.

Therapeutic vaccination is being explored as a treatment strategy for the treatment of patients with primary or metastatic tumours. We developed a vaccine targeted to Human papillomavirus (HPV)-induced tumours based on recombinant Semliki Forest virus (rSFV) encoding a fusion protein of the E6 and E7 proteins of HPV type 16. To enable a phase I clinical trial with this vaccine, Vvax001, a Good Manufacturing Practice (GMP)-compliant manufacturing process was set up and clinical material was produced. Upstream production of the clinical material resulted in viral titers from 2.4 × 107 to 1.3 × 109 infectious particles/ mL in the harvest. The total volume of 6.0 liter crude virus was purified in 13 consecutive downstream purification runs. The mean titer after purification was 4.0 × 108 infectious particles/ mL and the mean recovery was 19%. Finally, clinical material was filled at a target concentration of 1.25 × 108 infectious particles/mL. Release testing included tests for viral titer and virus identity, biological activity, sterility, bacterial endotoxins, adventitious viruses and absence of replication competent virus. The product complied with all specifications and was released for use as an investigational medicinal product. This is the first GMP production process developed for a SFV-based therapeutic vaccine. The vaccine, Vvax001 is targeted to HPV and has shown promising results in preclinical studies. The GMP-produced Vvax001 material met the quality criteria and was of sufficient quantity to enable assessment of its immunogenicity, safety and efficacy in a clinical setting.

Alphavirus-based hepatitis C virus therapeutic vaccines: can universal helper epitopes enhance HCV-specific cytotoxic T lymphocyte responses?

BACKGROUND: Antigen-specific T cell immune responses play a pivotal role in resolving acute and chronic hepatitis C virus (HCV) infections. Currently, no prophylactic or therapeutic vaccines against HCV are available. We previously demonstrated the preclinical potency of therapeutic HCV vaccines based on recombinant Semliki Forest virus (SFV) replicon particles. However, clinical trials do not always meet the high expectations of preclinical studies, thus, optimization of vaccine strategies is crucial. In efforts to further increase the frequency of HCV-specific immune responses in the candidate SFV-based vaccines, the authors assessed whether inclusion of three strong, so-called universal helper T cell epitopes, and an endoplasmic reticulum localization, and retention signal (collectively termed sigHELP-KDEL cassette) could enhance HCV-specific immune responses. METHODS: We included the sigHELP-KDEL cassette in two of the candidate SFV-based HCV vaccines, targeting NS3/4A and NS5A/B proteins. We characterized the new constructs in vitro for the expression and stability of the transgene-encoded proteins. Their immune efficacy with respect to HCV-specific immune responses in vivo was compared with the parental SFV vaccine expressing the corresponding HCV antigen. Further characterization of the functionality of the HCV-specific CD8+ T cells was assessed by surface and intracellular cytokine staining and flow cytometry analysis. RESULTS: Moderate, but significantly, enhanced frequencies of antigen-specific immune responses were achieved upon lower/suboptimal dosage immunization. In optimal dosage immunization, the inclusion of the cassette did not further increase the frequencies of HCV-specific CD8+ T cells when compared with the parental vaccines and the frequencies of effector and memory populations were identical. CONCLUSION: We hypothesize that the additional effect of the sigHELP-KDEL cassette in SFV-based vaccines depends on the immunogenicity, nature, and stability of the target antigen expressed by the vaccine.

Hepatitis C virus core or NS3/4A protein expression preconditions hepatocytes against oxidative stress and endoplasmic reticulum stress.

OBJECTIVES: The occurrence of oxidative stress and endoplasmic reticulum (ER) stress in hepatitis C virus (HCV) infection has been demonstrated and play an important role in liver injury. During viral infection, hepatocytes must handle not only the replication of the virus, but also inflammatory signals generating oxidative stress and damage. Although several mechanisms exist to overcome cellular stress, little attention has been given to the adaptive response of hepatocytes during exposure to multiple noxious triggers. METHODS: In the present study, Huh-7 cells and hepatocytes expressing HCV Core or NS3/4A proteins, both inducers of oxidative and ER stress, were additionally challenged with the superoxide anion generator menadione to mimic external oxidative stress. The production of reactive oxygen species (ROS) as well as the response to oxidative stress and ER stress were investigated. RESULTS: We demonstrate that hepatocytes diminish oxidative stress through a reduction in ROS production, ER-stress markers (HSPA5 [GRP78], sXBP1) and apoptosis (caspase-3 activity) despite external oxidative stress. Interestingly, the level of the autophagy substrate protein p62 was downregulated together with HCV Core degradation, suggesting that hepatocytes can overcome excess oxidative stress through autophagic degradation of one of the stressors, thereby increasing cell survival. Duscussion: In conclusion, hepatocytes exposed to direct and indirect oxidative stress inducers are able to cope with cellular stress associated with viral hepatitis and thus promote cell survival.

The cellular stress response in hepatitis C virus infection: A balancing act to promote viral persistence and host cell survival.

Oxidative- and endoplasmic reticulum (ER)-stress are common events during hepatitis C virus (HCV) infection and both regulate cell survival and determine clinical outcome. In response to intrinsic and extrinsic cellular stress, different adaptive mechanisms have evolved in hepatocytes to restore cellular homeostasis like the anti-oxidant response, the unfolded protein response (UPR) and the integrated stress response (ISR). In this review, we focus on the cellular stress response in the context of acute and chronic HCV infection. The mechanisms of induction and modulation of oxidative- and ER-stress are reviewed and analyzed from both perspectives: viral persistence and cell survival. Besides, we delve into the activation of the eIF2α/ATF4 pathway and selective autophagy induction; pathways involved in the elimination of harmful viral proteins after oxidative stress induction. For this, the negative role of autophagy upon HCV infection or negative regulation of viral replication is analyzed. Finally, we hypothesize that the cellular stress response in hepatocytes plays a major role for HCV control thus acting as an important host-factor for virus clearance during the early stages of HCV infection.

An alphavirus-based therapeutic cancer vaccine: from design to clinical trial.

Cancer immunotherapy has greatly advanced in recent years. Most immunotherapeutic strategies are based on the use of immune checkpoint blockade to unleash antitumor immune responses or on the induction or adoptive transfer of immune effector cells. We aim to develop therapeutic vaccines based on recombinant Semliki Forest virus vectors to induce tumor-specific effector immune cells. In this review, we describe our ongoing work on SFV-based vaccines targeted against human papillomavirus- and hepatitis C virus-related infections and malignancies, focusing on design, delivery, combination strategies, preclinical efficacy and product development for a first-in-man clinical trial with an HPV-specific vaccine.

Potent therapeutic efficacy of an alphavirus replicon DNA vaccine expressing human papilloma virus E6 and E7 antigens.

Cervical cancer develops as a result of infection with high-risk human papillomavirus (HPV) through persistent expression of early proteins E6 and E7. Our group pioneered a recombinant viral vector system based on Semliki Forest virus (SFV) for vaccination against cervical cancer. The most striking benefit of this alphavirus vector-based vaccine platform is its high potency. DNA vaccines on the other hand, have a major advantage with respect to ease of production. In this study, the benefits associated with both SFV-based vaccines and DNA vaccines were combined with the development of a DNA-launched RNA replicon (DREP) vaccine targeting cervical cancer. Using intradermal delivery followed by electroporation, we demonstrated that DREP encoding for E6,7 (DREP-E6,7) induced effective, therapeutic antitumor immunity. While immunizations with a conventional DNA vaccine did not prevent tumor outgrowth, immunization with a 200-fold lower equimolar dose of DREP (0.05 µg of DREP) resulted in approximately 85% of tumor-free mice. To overcome the safety concern of potential malignant transformation at the vaccination site, we evaluated the anti-tumor effect of a DREP vaccine encoding a shuffled version of E7 (DREP-E7sh). DREP-E7sh delayed tumor growth yet not to the same extent as DREP-E6,7. In addition, inclusion of a helper cassette and an ER targeting signal (sigHelp) did not significantly further enhance the suppression of tumor outgrowth in the long term, albeit exhibiting better tumor control early after immunization. Collectively, this study points towards the clinical evaluation of DREP encoding HPV antigens as a potent immunotherapy for patients with HPV16 (pre)-malignancies.

Antigen-specific active immunotherapy for ovarian cancer.

BACKGROUND: This is the second update of the review first published in the Cochrane Library (2010, Issue 2) and later updated (2014, Issue 9).Despite advances in chemotherapy, the prognosis of ovarian cancer remains poor. Antigen-specific active immunotherapy aims to induce tumour antigen-specific anti-tumour immune responses as an alternative treatment for ovarian cancer. OBJECTIVES: Primary objective• To assess the clinical efficacy of antigen-specific active immunotherapy for the treatment of ovarian cancer as evaluated by tumour response measured by Response Evaluation Criteria In Solid Tumors (RECIST) and/or cancer antigen (CA)-125 levels, response to post-immunotherapy treatment, and survival differences◦ In addition, we recorded the numbers of observed antigen-specific humoral and cellular responsesSecondary objective• To establish which combinations of immunotherapeutic strategies with tumour antigens provide the best immunological and clinical results SEARCH METHODS: For the previous version of this review, we performed a systematic search of the Cochrane Central Register of Controlled Trials (CENTRAL; 2009, Issue 3), in the Cochrane Library, the Cochrane Gynaecological Cancer Group Specialised Register, MEDLINE and Embase databases, and clinicaltrials.gov (1966 to July 2009). We also conducted handsearches of the proceedings of relevant annual meetings (1996 to July 2009).For the first update of this review, we extended the searches to October 2013, and for this update, we extended the searches to July 2017. SELECTION CRITERIA: We searched for randomised controlled trials (RCTs), as well as non-randomised studies (NRSs), that included participants with epithelial ovarian cancer, irrespective of disease stage, who were treated with antigen-specific active immunotherapy, irrespective of type of vaccine, antigen used, adjuvant used, route of vaccination, treatment schedule, and reported clinical or immunological outcomes. DATA COLLECTION AND ANALYSIS: Two reviews authors independently extracted the data. We evaluated the risk of bias for RCTs according to standard methodological procedures expected by Cochrane, and for NRSs by using a selection of quality domains deemed best applicable to the NRS. MAIN RESULTS: We included 67 studies (representing 3632 women with epithelial ovarian cancer). The most striking observations of this review address the lack of uniformity in conduct and reporting of early-phase immunotherapy studies. Response definitions show substantial variation between trials, which makes comparison of trial results unreliable. Information on adverse events is frequently limited. Furthermore, reports of both RCTs and NRSs frequently lack the relevant information necessary for risk of bias assessment. Therefore, we cannot rule out serious biases in most of the included trials. However, selection, attrition, and selective reporting biases are likely to have affected the studies included in this review. GRADE ratings were high only for survival; for other primary outcomes, GRADE ratings were very low.The largest body of evidence is currently available for CA-125-targeted antibody therapy (17 studies, 2347 participants; very low-certainty evidence). Non-randomised studies of CA-125-targeted antibody therapy suggest improved survival among humoral and/or cellular responders, with only moderate adverse events. However, four large randomised placebo-controlled trials did not show any clinical benefit, despite induction of immune responses in approximately 60% of participants. Time to relapse with CA-125 monoclonal antibody versus placebo, respectively, ranged from 10.3 to 18.9 months versus 10.3 to 13 months (six RCTs, 1882 participants; high-certainty evidence). Only one RCT provided data on overall survival, reporting rates of 80% in both treatment and placebo groups (three RCTs, 1062 participants; high-certainty evidence). Other small studies targeting many different tumour antigens have presented promising immunological results. As these strategies have not yet been tested in RCTs, no reliable inferences about clinical efficacy can be made. Given the promising immunological results and the limited side effects and toxicity reported, exploration of clinical efficacy in large well-designed RCTs may be worthwhile. AUTHORS' CONCLUSIONS: We conclude that despite promising immunological responses, no clinically effective antigen-specific active immunotherapy is yet available for ovarian cancer. Results should be interpreted cautiously, as review authors found a significant dearth of relevant information for assessment of risk of bias in both RCTs and NRSs.

Changes in (risk) behavior and HPV knowledge among Dutch girls eligible for HPV vaccination: an observational cohort study.

BACKGROUND: Implementation of human papillomavirus (HPV) vaccination raised concerns that vaccination could lead to riskier sexual behavior. This study explored how possible differences in sexual behavior and HPV knowledge developed over time between HPV-vaccinated and unvaccinated girls. METHODS: A random sample of 19,939 girls (16-17 year olds) eligible for the catch-up HPV vaccination campaign in the Netherlands was invited for a longitudinal study with questionnaires every 6 months over a two-year follow-up period. Possible differences over time between vaccinated and unvaccinated participants were studied using generalized equations estimation (GEE). RESULTS: A total of 2989 girls participated in round one, of which 1574 participated (52.7%) in the final 5th round. Vaccinated girls were more likely to live in more urban areas (OR 1.28, 95%CI 1.10-1.47) and to use alcohol (OR 1.46, 95%CI 1.24-1.70) and contraceptives (OR 1.69, 95%CI 1.45-1.97). Vaccinated and unvaccinated girls showed comparable knowledge on HPV, HPV vaccination, and transmission. Vaccinated girls were more likely to be sexually active (OR 1.19, 95%CI 1.02-1.39), and this difference increased over time (OR for interaction 1.06, 95%CI 1.00-1.12). However, they had a slightly lower number of lifetime sexual partners (mean difference - 0.20, 95%CI -0.41-0.00). Vaccinated girls were less likely to use a condom with a steady partner (aOR 0.71, 95%CI 0.56-0.89). However, the difference between vaccinated and unvaccinated girls with regard to condom use with casual or steady partner(s) did not significantly change over time. CONCLUSION: Overall, we did not find indications that vaccination influenced sexual behavior in girls during 2 years of follow-up. The few differences found may be related to existing disparities in the socio-demographic characteristics of the young population pointing to the importance and improvement of education with regard to safe sex practices. Our findings do not suggest that vaccination status is associated with changes in sexual risk behavior and thus it is unlikely that this might influence the effectiveness of the vaccination program.