Therapeutic Vaccines for HPV-Associated Malignancies

Human Papillomavirus and Associated Cancers: A Review

The human papillomavirus is the most common sexually transmitted infection in the world. Most HPV infections clear spontaneously within 2 years of infection; however, persistent infection can result in a wide array of diseases, ranging from genital warts to cancer. Most cases of cervical, anal, and oropharyngeal cancers are due to HPV infection, with cervical cancer being one of the leading causes of cancer death in women worldwide. Screening is available for HPV and cervical cancer, but is not available everywhere, particularly in lower-resource settings. HPV infection disproportionally affects individuals living with HIV, resulting in decreased clearance, increased development of cancer, and increased mortality. The development of the HPV vaccine has shown a drastic decrease in HPV-related diseases. The vaccine prevents cervical cancer with near 100% efficacy, if given prior to first sexual activity. Vaccination uptake remains low worldwide due to a lack of access and limited knowledge of HPV. Increasing awareness of HPV and access to vaccination are necessary to decrease cancer and HPV-related morbidity and mortality worldwide.

Tumor Antigens beyond the Human Exome

With the advent of immunotherapeutics, a new era in the combat against cancer has begun. Particularly promising are neo-epitope-targeted therapies as the expression of neo-antigens is tumor-specific. In turn, this allows the selective targeting and killing of cancer cells whilst healthy cells remain largely unaffected. So far, many advances have been made in the development of treatment options which are tailored to the individual neo-epitope repertoire. The next big step is the achievement of efficacious "off-the-shelf" immunotherapies. For this, shared neo-epitopes propose an optimal target. Given the tremendous potential, a thorough understanding of the underlying mechanisms which lead to the formation of neo-antigens is of fundamental importance. Here, we review the various processes which result in the formation of neo-epitopes. Broadly, the origin of neo-epitopes can be categorized into three groups: canonical, noncanonical, and viral neo-epitopes. For the canonical neo-antigens that arise in direct consequence of somatic mutations, we summarize past and recent findings. Beyond that, our main focus is put on the discussion of noncanonical and viral neo-epitopes as we believe that targeting those provides an encouraging perspective to shape the future of cancer immunotherapeutics.

Therapeutic Vaccines for HPV-Associated Cervical Malignancies: A Systematic Review

IMPORTANCE

Despite widespread prophylactic vaccination, cervical cancer continues to be a major health problem with considerable mortality. Currently, therapeutic vaccines for HPV-associated cervical malignancies are being evaluated as a potential complement to the standard treatment.

OBJECTIVE

The present systematic review was conducted on randomized controlled trials (RCTs) to investigate the effects of therapeutic vaccines on the treatment of patients with cervical cancer and cervical intraepithelial neoplasia (CIN) of Grades 2 and 3.

EVIDENCE REVIEW

The PubMed, Embase, and Cochrane Central Register of Controlled Trials databases were searched. Only articles in English published up until 31 January 2024 were selected. Also, reference lists of the selected original papers and recent review articles were manually searched for additional sources. Data on study characteristics were extracted from the selected articles. Data on outcomes of interest were synthesized, and vaccine efficacy endpoints (histological lesion regression, clinical response, and overall survival) were selected as the basis for grouping the studies.

FINDINGS

After screening 831 articles, nine RCTs with 800 participants were included, of which seven studies with 677 participants involved CIN2 and CIN3 and examined lesion regression to ≤CIN1 as the efficacy endpoint. Results of two of these studies were deemed to have a high risk of bias, and another one did not contain statistical analyses. Results of the other four studies were quantitively synthesized, and the pooling of p-values revealed a significant difference between the vaccine and placebo groups in terms of lesion regression (p-values of 0.135, 0.049, and 0.034 in RCTs, yielding a combined p-value of 0.010). The certainty of the evidence was rated as moderate. Patients with advanced cervical cancers were studied in two RCTs with 123 participants. Clinical response and overall survival were taken as endpoints, and the results were reported as not significant. The certainty of the evidence of these results was rated as very low, mainly due to the very small number of events. All studies reported good tolerance for the vaccines.

CONCLUSIONS AND RELEVANCE

The results indicate the potential for therapeutic vaccines in the regression of CIN2 and CIN3 lesions. Moreover, a potential gap in evidence is identified regarding the very low number of RCTs in patients with advanced cervical cancer.

A promising area of research in medicine: recent advances in properties and applications of Lactobacillus-derived exosomes

Lactobacillus-derived exosomes, small extracellular vesicles released by bacteria, have emerged as a promising area of research in recent years. These exosomes possess a unique structural and functional diversity that allows them to regulate the immune response and promote gut health. The isolation and purification of these exosomes are crucial for their effective use as a therapeutic agent. Several isolation and purification methods have been developed, including differential ultracentrifugation, density gradient centrifugation, and size-exclusion chromatography. Lactobacillus-derived exosomes have been demonstrated to have therapeutic potential in various diseases, such as inflammatory bowel disease, liver disease, and neurological disorders. Moreover, they have been shown to serve as effective carriers for drug delivery. Genetic engineering of these exosomes has also shown promise in enhancing their therapeutic potential. Overall, Lactobacillus-derived exosomes represent a promising area of research for the development of novel therapeutics for immunomodulation, gut health, and drug delivery.

Vaccines for HPV-associated diseases

Human papillomavirus (HPV) infection represents a significant global health concern owing to its role in the etiology of conditions ranging from benign low-grade lesions to cancers of the cervix, head and neck, anus, vagina, vulva, and penis. Prophylactic vaccination programs, primarily targeting adolescent girls, have achieved dramatic reductions in rates of HPV infection and cervical cancer in recent years. However, there is a clear demand for a strategy to manage the needs of the many people who are already living with persistent HPV infection and/or HPV-associated conditions. Unlike prophylactic vaccines, which act to prevent HPV infection, therapeutic vaccination presents an opportunity to induce cellular immunity against established HPV infections and lesions and prevent progression to cancer. Several HPV vaccines are undergoing clinical development, using a range of platforms. Peptide- or protein-based vaccines, vector-based vaccines, whole-cell vaccines, and nucleic acid vaccines each offer relative merits and limitations for the delivery of HPV antigens and the subsequent generation of targeted immune responses. There has been particular interest in DNA-based vaccines, which elicit both cellular and humoral immune responses to provide long-lasting immunity. DNA vaccines offer several practical advantages over other vaccine platforms, including the potential for rapid and scalable manufacturing, targeting of many different antigens, and potential for repeat boosting. Furthermore, unlike vectored approaches, DNA vaccines are thermostable over extended time periods, which may enable shipping and storage. Several delivery strategies are available to address the main challenge of DNA vaccines, namely their relatively low transfection efficiency. We review the latest clinical data supporting the development of DNA vaccines and reflect on this exciting prospect in the management of HPV-related disease.

Assessing the Genomic Landscape of Cervical Cancers: Clinical Opportunities and Therapeutic Targets

PURPOSE

Tumor genomic profiling is increasingly used to guide treatment strategy in patients with cancer. We integrated tumor genomic, clinical demographic, and treatment response data to assess how prospective tumor-normal sequencing impacted treatment selection in patients with cervical cancer.

EXPERIMENTAL DESIGN

Cervical cancers were prospectively analyzed using the MSK-IMPACT (Memorial Sloan Kettering Cancer Center - Integrated Mutation Profiling of Actionable Cancer Targets) next-generation sequencing panel. Clinical data, including histology, stage at diagnosis, treatment history, clinical trial enrollment and outcomes, date of last follow-up, and survival status were obtained from medical records.

RESULTS

A total of 177 patients with cervical cancer (squamous, 69; endocervical adenocarcinoma, 50; gastric type, 22; adenosquamous, 21; and other, 15) underwent MSK-IMPACT testing. The most prevalent genomic alterations were somatic mutations or amplifications in PIK3CA (25%), ERBB2 (12%), KMT2C (10%), and KMT2D (9%). Furthermore, 13% of patients had high tumor mutational burden (TMB >10 mut/Mb), 3 of which were also microsatellite instability-high (MSI-H). Thirty-seven percent of cases had at least one potentially actionable alteration designated as a level 3B mutational event according to the FDA-recognized OncoKB tumor mutation database and treatment classification system. A total of 30 patients (17%) were enrolled on a therapeutic clinical trial, including 18 (10%) who were matched with a study based on their MSK-IMPACT results. Twenty patients (11%) participated in an immune checkpoint inhibition study for metastatic disease; 2 remain progression free at >5 years follow-up.

CONCLUSIONS

Tumor genomic profiling can facilitate the selection of targeted/immunotherapies, as well as clinical trial enrollment, for patients with cervical cancer.

The tumor microenvironment state associates with response to HPV therapeutic vaccination in patients with respiratory papillomatosis

Recurrent respiratory papillomatosis (RRP) is a rare, debilitating neoplastic disorder caused by chronic infection with human papillomavirus (HPV) type 6 or 11 and characterized by growth of papillomas in the upper aerodigestive tract. There is no approved medical therapy, and patients require repeated debulking procedures to maintain voice and airway function. PRGN-2012 is a gorilla adenovirus immune-therapeutic capable of enhancing HPV 6/11-specific T cell immunity. This first-in-human, phase 1 study (NCT04724980) of adjuvant PRGN-2012 treatment in adult patients with severe, aggressive RRP demonstrates the overall safety and clinically meaningful benefit observed with PRGN-2012, with a 50% complete response rate in patients treated at the highest dose. Responders demonstrate greater expansion of peripheral HPV-specific T cells compared with nonresponders. Additional correlative studies identify an association between reduced baseline papilloma HPV gene expression, greater interferon responses and expression of CXCL9 and CXCL10, and greater papilloma T cell infiltration in responders. Conversely, nonresponders were characterized by greater HPV and CXCL8 gene expression, increased neutrophilic cell infiltration, and reduced T cell papilloma infiltration. These results suggest that papilloma HPV gene expression may regulate interferon signaling and chemokine expression profiles within the tumor microenvironment that cooperate to govern clinical response to therapeutic HPV vaccination in patients with respiratory papillomatosis.

Efficacy and safety of therapeutic HPV vaccines to treat CIN 2/CIN 3 lesions: a systematic review and meta-analysis of phase II/III clinical trials

OBJECTIVES

We aim to assess the efficacy and safety of therapeutic human papillomavirus (HPV) vaccines to treat cervical intraepithelial neoplasia of grade 2 or 3 (CIN 2/3).

DESIGN

Systematic review and meta-analysis, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations.

DATA SOURCES

PubMed, Embase, Web of Science, Global Index Medicus and CENTRAL Cochrane were searched up to 31 January 2022.

ELIGIBILITY CRITERIA

Phase II/III randomised controlled trials (RCTs) and single-arm studies reporting the efficacy of therapeutic vaccines to achieve regression of CIN 2/3 lesions were included. Studies evaluating only safety and side effects of the vaccine were excluded.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data and evaluated study quality. A random-effect model was used to pool the proportions of regression and/or HPV clearance.

RESULTS

12 trials met the inclusion criteria. Out of 734 women (all studies considered) receiving therapeutic HPV vaccine for CIN 2/3, 414 regressed to normal/CIN 1 with an overall proportion of regression of 0.54 (95% CI 0.39 to 0.69) for vaccinated group; 166 women (from five RCTs) receiving placebo only achieving a pooled normal/CIN 1 regression of 0.27 (95% CI 0.20 to 0.34). When including only the five two-arm studies, the regression proportion for the 410 vaccine group participants was higher than that of the 166 control group participants (relative risk (RR) 1.52; 95% CI 1.14 to 2.04). The pooled proportion of high-risk human papillomavirus (hrHPV) clearance was 0.42 (95% CI 0.32 to 0.52) in the vaccine group (six studies with a total of 357 participants) and 0.17 (95% CI 0.11 to 0.26) in the control group (three RCTs with a total of 104 participants). Based on these three RCTs, the hrHPV clearance was significantly higher in the vaccinated group (250 participants) compared with the control group (RR 2.03; 95% CI 1.30 to 3.16). Similar results were found regarding HPV 16/18 clearance. No significant unsolicited adverse events have been consistently reported.

CONCLUSIONS

The efficacy of the therapeutic vaccines in the treatment of CIN 2/3 was modest. Implementation issues such as feasibility, acceptability, adoption and cost-effectiveness need to be further studied.

PROSPERO REGISTRATION NUMBER

CRD42022307418.

Full eradication of pre-clinical human papilloma virus-induced tumors by a lentiviral vaccine

Human papillomavirus (HPV) infections are the cause of all cervical and numerous oropharyngeal and anogenital cancers. The currently available HPV vaccines, which induce neutralizing antibodies, have no therapeutic effect on established tumors. Here, we developed an immuno-oncotherapy against HPV-induced tumors based on a non-integrative lentiviral vector encoding detoxified forms of the Early E6 and E7 oncoproteins of HPV16 and 18 genotypes, namely, "Lenti-HPV-07". A single intramuscular injection of Lenti-HPV-07 into mice bearing established HPV-induced tumors resulted in complete tumor eradication in 100% of the animals and was also effective against lung metastases. This effect correlated with CD8+ T-cell induction and profound remodeling of the tumor microenvironment. In the intra-tumoral infiltrates of vaccinated mice, the presence of large amounts of activated effector, resident memory, and transcription factor T cell factor-1 (TCF-1)+ "stem-like" CD8+ T cells was associated with full tumor eradication. The Lenti-HPV-07-induced immunity was long-lasting and prevented tumor growth after a late re-challenge, mimicking tumor relapse. Lenti-HPV-07 therapy synergizes with an anti-checkpoint inhibitory treatment and therefore shows promise as an immuno-oncotherapy against established HPV-mediated malignancies.

Immunoinformatics applications in the development of therapeutic vaccines against human papillomavirus-related infections and cervical cancer

The human papillomavirus (HPV) represents the most prevalent sexually transmitted infectious agent worldwide. HPV penetrates the epithelium through microlesions and establishes an infectious focus that can lead to the development of cervical cancer. Prophylactic HPV vaccines are available, but do not affect already-established infections. Using in silico prediction tools is a promising strategy for identifying and selecting vaccine candidate T cell epitopes. An advantage of this strategy is that epitopes can be selected according to the degree of conservation within a group of antigenic proteins. This makes achieving comprehensive genotypic coverage possible with a small set of epitopes. Therefore, this paper revises the general characteristics of HPV biology and the current knowledge on developing therapeutic peptide vaccines against HPV-related infections and cervical cancer.

Advancing Immunotherapies for HPV-Related Cancers: Exploring Novel Vaccine Strategies and the Influence of Tumor Microenvironment

The understanding of the relationship between immunological responses and cancers, especially those related to HPV, has allowed for the study and development of therapeutic vaccines against these neoplasias. There is a growing number of studies about the composition and influence of the tumor microenvironment (TME) in the progression or establishment of the most varied types of cancer. Hence, it has been possible to structure immunotherapy approaches based on therapeutic vaccines that are even more specific and directed to components of TME and the immune response associated with tumors. Among these components are dendritic cells (DCs), which are the main professional antigen-presenting cells (APCs) already studied in therapy strategies for HPV-related cancers. On the other hand, tumor-associated macrophages are also potential targets since the profile present in tumor infiltrates, M1 or M2, influences the prognosis of some types of cancer. These two cell types can be targets for therapy or immunomodulation. In this context, our review aims to provide an overview of immunotherapy strategies for HPV-positive tumors, such as cervical and head and neck cancers, pointing to TME immune cells as promising targets for these approaches. This review also explores the potential of immunotherapy in cancer treatment, including checkpoint inhibitors, cytokine immunotherapies, immunotherapy vaccines, and cell therapies. Furthermore, it highlights the importance of understanding the TME and its effect on the design and achievement of immunotherapeutic methods.

NSP4 as adjuvant for immunogenicity and design of effective therapeutic HPV16 E6/E7/L1 DNA vaccine in tumor-bearing and healthy C57BL/6 mice

INTRODUCTION

In humans, approximately 5% of all cancers are attributable to HPV infection. Prophylactic vaccines can inhibit viral migration and persistence. However, further studies are still required to develop such treatments. To achieve this goal, we designed a therapeutic HPV DNA vaccine encoding a construct of E6/E7/L1 and used NSP4 antigen as an adjuvant to assess the efficiency of this construct in generating antigen-specific antitumor immune responses.

MATERIALS AND METHODS

Sixty female C57BL/6 mice (6-8 weeks old) were purchased from the Institute Pasteur of Iran. Through a subcutaneous (s.c) injection of a suspension of 100 µl PBS containing 106 TC-1 cells/mouse in the back side, 30 of them became cancerous, while 30 of them were healthy control mice. To amplify E6/E7/L1-pcDNA3 and NSP4-pcDNA3, the competent cells of DH5α and to generate a tumor, TC-1 cell line was used. Mice were then immunized with the HPV DNA vaccine. Cell proliferation was assessed by MTT assay. Finally, cytokine responses (IL-4, IL-12, IFN- γ) were measured in the supernatant of mice spleen cells.

RESULT

Mice receiving the NSP4/E6-E7-L1 vaccine had the highest stimulatory index compared to other groups, although it was not statistically significant. Interleukin 4/12 and IFN-γ production were significantly higher in E6-E7-L1 / NSP4 group and E6-E7-L1 group compared to other groups (P < 0.05). Among different groups, E6/E7/L1 + NSP4 group was able to slow down the tumor growth process, but it was not significant (p > 0.05). Among the aforementioned cytokines, IFN-γ and IL-12 are among the cytokines that stimulate the Th1 pathway and IL-4 cytokine stimulates the Th2 pathway and B lymphocytes.

CONCLUSION

Our data revealed that the present vaccine can reduce tumor size, and cytokine measurement showed that it stimulates innate and acquired immune responses, thus it can be a therapeutic vaccine in the tumor-bearing mice model.

Effect of a Multi-Ingredient Coriolus-versicolor-Based Vaginal Gel in Women with HPV-Dependent Cervical Lesions: The Papilobs Real-Life Prospective Study

Human papillomavirus (HPV) is responsible for virtually all cervical cancers in women. HPV infection and persistency may lead to different-grade squamous intraepithelial lesions that can result in high-grade lesions and cancer. The objective was to prospectively evaluate the results of using a Coriolus-versicolor-based vaginal gel (Papilocare®) on HPV-dependent low-grade cervical lesion repair in a real-life scenario. HPV-positive women ≥ 25 years with ASCUS/LSIL cervical cytology results and concordant colposcopy images were included, receiving the vaginal gel one cannula/day for 21 days (first month) + one cannula/alternate days (five months). A 6-month second treatment cycle was prescribed when needed. Repair of the cervical low-grade lesions through cytology and colposcopy, HPV clearance, and level of satisfaction, and tolerability were evaluated. In total, 192 and 201 patients accounted for the total and safety analyses, respectively, and 77.1% repaired cervical lesions at 6 or 12 months (76.0% for high-risk HPV). Additionally, 71.6% achieved HPV clearance throughout the study's duration (70.6% for high-risk HPV). Satisfaction level was rated 7.9 and 7.5 out of 10 at 6 and 12 months, respectively. Only three mild-moderate product-related adverse events were reported, and all of them were resolved by the end of the study. In our study, we observed higher regression rates of low-grade cervical lesions in women treated with Papilocare® vaginal gel than spontaneous regression rates reported in the literature.

HPV16 E6/E7 -based mRNA vaccine is therapeutic in mice bearing aggressive HPV-positive lesions

HPV (Human papillomavirus) affects 600,000 people worldwide each year. Almost all cervical cancers are associated with a past HPV infection. In particular, the positivity to the high-risk type HPV16 is detected in most of the invasive cervical cancers. FDA has approved prophylactic vaccines that protect against new HPV16 infections, but do not induce immunity in those patients with established infections or neoplasms. To date, no therapeutic vaccine targeting HPV16-associated lesions has been authorized. We have developed an mRNA-based vaccine against the HPV16 late oncoproteins E6 and E7, which are abundantly and exclusively expressed in high-grade squamous intraepithelial lesions (HSILs), a stage of the cervical disease that precedes the progression to carcinoma. Our in vitro and in vivo studies demonstrated that the translated mRNA is functional and elicits an antigen-specific adaptive immune response. Upon immunization with the vaccine, mice with HPV16+ lesions exhibited tumor growth inhibition, extension of lifespan, and development of a protective immune memory. In light of these results and the remarkable clinical success of mRNA vaccines against SARS-CoV2, we believe that our mRNA-based therapeutic vaccine has the potential to offer a non-invasive treatment alternative to the current standard of care for HPV16+ HSILs.

Development of HPV16 mouse and dog models for more accurate prediction of human vaccine efficacy

BACKGROUND

Animal models are essential to understand the physiopathology of human diseases but also to evaluate new therapies. However, for several diseases there is no appropriate animal model, which complicates the development of effective therapies. HPV infections, responsible for carcinoma cancers, are among these. So far, the lack of relevant animal models has hampered the development of therapeutic vaccines. In this study, we used a candidate therapeutic vaccine named C216, similar to the ProCervix candidate therapeutic vaccine, to validate new mouse and dog HPV preclinical models. ProCervix has shown promising results with classical subcutaneous murine TC-1 cell tumor isografts but has failed in a phase II study.

RESULTS

We first generated E7/HPV16 syngeneic transgenic mice in which the expression of the E7 antigen could be switched on through the use of Cre-lox recombination. Non-integrative LentiFlash^® viral particles were used to locally deliver Cre mRNA, resulting in E7/HPV16 expression and GFP reporter fluorescence. The expression of E7/HPV16 was monitored by in vivo fluorescence using Cellvizio imaging and by local mRNA expression quantification. In the experimental conditions used, we observed no differences in E7 expression between C216 vaccinated and control groups. To mimic the MHC diversity of humans, E7/HPV16 transgenes were locally delivered by injection of lentiviral particles in the muscle of dogs. Vaccination with C216, tested with two different adjuvants, induced a strong immune response in dogs. However, we detected no relationship between the level of cellular response against E7/HPV16 and the elimination of E7-expressing cells, either by fluorescence or by RT-ddPCR analysis.

CONCLUSIONS

In this study, we have developed two animal models, with a genetic design that is easily transposable to different antigens, to validate the efficacy of candidate vaccines. Our results indicate that, despite being immunogenic, the C216 candidate vaccine did not induce a sufficiently strong immune response to eliminate infected cells. Our results are in line with the failure of the ProCervix vaccine that was observed at the end of the phase II clinical trial, reinforcing the relevance of appropriate animal models.

Precision and correlation of ED50 and endpoint titer method in measuring HPV vaccine immunogenicity

Cervical cancer, the second leading cause of cancer-related deaths among women, is caused by human papillomavirus (HPV), a sexually transmitted virus. Vaccination is an effective preventive measure against viral infections and subsequent development of cervical cancer. Enzyme-linked immunosorbent assay (ELISA) is commonly used to measure specific binding antibody titers and assess the immunogenicity of test vaccines in preclinical models or clinical volunteers. Two methods of deriving titers, the endpoint titer (ET) and the effective dilution producing a median maximal effective fold of dilution (ED50) with a cut-off value, are widely used. For HPV, a pseudovirion-based neutralization assay (PBNA) is used to measure functional antibody titers. The ELISA binding titers and functional PBNA titers were found to be well-correlated for all nine HPV types tested in the vaccine, consistent with previous studies on HPV 16/18. Comparing the PBNA results with the two titration methods, the ED50 method showed higher precision and a closer correlation with PBNA results, both for individual types and pooled data analysis for all nine types. When comparing the titration results of the ET method based on a cut-off value with the ED50 method using all the data points across the dilution series, the ED50 method demonstrated better precision and a stronger correlation with PBNA results.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of gynecologic cancer

Advanced gynecologic cancers have historically lacked effective treatment options. Recently, immune checkpoint inhibitors (ICIs) have been approved by the US Food and Drug Administration for the treatment of cervical cancer and endometrial cancer, offering durable responses for some patients. In addition, many immunotherapy strategies are under investigation for the treatment of earlier stages of disease or in other gynecologic cancers, such as ovarian cancer and rare gynecologic tumors. While the integration of ICIs into the standard of care has improved outcomes for patients, their use requires a nuanced understanding of biomarker testing, treatment selection, patient selection, response evaluation and surveillance, and patient quality of life considerations, among other topics. To address this need for guidance, the Society for Immunotherapy of Cancer (SITC) convened a multidisciplinary panel of experts to develop a clinical practice guideline. The Expert Panel drew on the published literature as well as their own clinical experience to develop evidence- and consensus-based recommendations to provide guidance to cancer care professionals treating patients with gynecologic cancer.

The Tumor-Specific Immune Landscape in HPV+ Head and Neck Cancer

Human papillomaviruses (HPVs) are the causative agent of several anogenital cancers as well as head and neck cancers, with HPV+ head and neck squamous cell carcinoma (HNSCC) becoming a rapidly growing public health issue in the Western world. Due its viral etiology and potentially its subanatomical location, HPV+ HNSCC exhibits an immune microenvironment which is more inflamed and thus distinct from HPV-negative HNSCC. Notably, the antigenic landscape in most HPV+ HNSCC tumors extends beyond the classical HPV oncoproteins E6/7 and is extensively targeted by both the humoral and cellular arms of the adaptive immune system. Here, we provide a comprehensive overview of HPV-specific immune responses in patients with HPV+ HNSCC. We highlight the localization, antigen specificity, and differentiation states of humoral and cellular immune responses, and discuss their similarities and differences. Finally, we review currently pursued immunotherapeutic treatment modalities that attempt to harness HPV-specific immune responses for improving clinical outcomes in patients with HPV+ HNSCC.

Armored modified vaccinia Ankara in cancer immunotherapy

Cancer immunotherapy relies on unleashing the patient´s immune system against tumor cells. Cancer vaccines aim to stimulate both the innate and adaptive arms of immunity to achieve durable clinical responses. Some roadblocks for a successful cancer vaccine in the clinic include the tumor antigen of choice, the adjuvants employed to strengthen antitumor-specific immune responses, and the risks associated with enhancing immune-related adverse effects in patients. Modified vaccinia Ankara (MVA) belongs to the family of poxviruses and is a versatile vaccine platform that combines several attributes crucial for cancer therapy. First, MVA is an excellent inducer of innate immune responses leading to type I interferon secretion and induction of T helper cell type 1 (Th1) immune responses. Second, it elicits robust and durable humoral and cellular immunity against vector-encoded heterologous antigens. Third, MVA has enormous genomic flexibility, which allows for the expression of multiple antigenic and costimulatory entities. And fourth, its replication deficit in human cells ensures a excellent safety profile. In this review, we summarize the current understanding of how MVA induces innate and adaptive immune responses. Furthermore, we will give an overview of the tumor-associated antigens and immunomodulatory molecules that have been used to armor MVA and describe their clinical use. Finally, the route of MVA immunization and its impact on therapeutic efficacy depending on the immunomodulatory molecules expressed will be discussed.

Human Papilloma Virus: An Unraveled Enigma of Universal Burden of Malignancies

HPV, or Human Papilloma Virus, has been the primary causative agent of genital warts and cervical cancer worldwide. It is a sexually transmitted infection mainly affecting women of reproductive age group, also infecting men and high-risk group individuals globally, resulting in high mortality. In recent years, HPV has also been found to be the major culprit behind anogenital cancers in both gender and oropharyngeal and colorectal cancers. Few studies have reported the incidence of HPV in breast cancers as well. For a few decades, the burden of HPV-associated malignancies has been increasing at an alarming rate due to a lack of adequate awareness, famine vaccine coverage and hesitancy. The effectiveness of currently available vaccines has been limited to prophylactic efficacy and does not prevent malignancies associated with post-exposure persistent infection. This review focuses on the current burden of HPV-associated malignancies, their causes and strategies to combat the growing prevalence of the cancers. With the advent of new technologies associated with treatment pertaining to therapeutic interventions and employing effective vaccine coverage, the burden of this disease may be reduced in the population.

A sugar modified amphiphilic cationic nano-adjuvant ceased tumor immune suppression and rejuvenated peptide vaccine induced antitumor immunity in cervical cancer

Human papilloma virus (HPV), one of the most common cancer-causing viruses, accounts for more than 90% of human anal and cervical cancers. Clinical studies have focused on adjuvant therapy with vaccines to improve therapeutic outcomes in patients with late-stage HPV-related cancers. In the present study, a mannose receptor (CD206) targeting a lithocholic acid-modified polyethylenimine (PEI) nano-adjuvant delivering the toll-like receptor 7/8 agonist, resiquimod (R848) (mLAPMi-R848), in a HPV E6- and E7-expressing TC-1 tumor murine model was developed. Peritumoral administration of mLAPMi resulted in enhanced accumulation in tumor/tumor-draining lymph nodes and significantly targeted antigen presenting cells like macrophage and dendritic cells. PEI-based nanocarriers can exploit the adjuvant potency of R848 and improve the antitumor immunity. Hence, co-administration of mLAPMi-R848 along with an E6E7 peptide in TC-1 tumor mice eradicated tumor burden and elicited splenocyte-induced cytotoxicity in TC-1 cancer cells. In a bilateral TC-1 tumor model, administration of mLAPMi-R848 and E6E7 peptide significantly suppressed both primary and secondary tumor burdens and improved the overall survival rate. Immune cell profiling revealed elevated levels of mature DCs and CD8+ T cells but reduced levels of tumor-associated immunosuppressive cells (TAICs) like myeloid derived suppressor cells (MDSCs) and regulatory T (Treg) cells in distal tumors. Overall, this study demonstrated that mLAPMi-R848 has improved the antitumor immunity of the peptide antigen against HPV-induced cancers by targeted immunodulation of antigen presenting cells (APCs) and reducing TAICs. Furthermore, this nano-adjuvant has the potential to offer a new treatment option for patients with cervical cancer and can be applied for the treatment of other HPV induced cancers.

mRNA-Based Therapeutics in Cancer Treatment

Over the past two decades, significant technological innovations have led to messenger RNA (mRNA) becoming a promising option for developing prophylactic and therapeutic vaccines, protein replacement therapies, and genome engineering. The success of the two COVID-19 mRNA vaccines has sparked new enthusiasm for other medical applications, particularly in cancer treatment. In vitro-transcribed (IVT) mRNAs are structurally designed to resemble naturally occurring mature mRNA. Delivery of IVT mRNA via delivery platforms such as lipid nanoparticles allows host cells to produce many copies of encoded proteins, which can serve as antigens to stimulate immune responses or as additional beneficial proteins for supplements. mRNA-based cancer therapeutics include mRNA cancer vaccines, mRNA encoding cytokines, chimeric antigen receptors, tumor suppressors, and other combination therapies. To better understand the current development and research status of mRNA therapies for cancer treatment, this review focused on the molecular design, delivery systems, and clinical indications of mRNA therapies in cancer.

Towards Novel Gene and Cell Therapy Approaches for Cervical Cancer

Cervical cancer is one of the most common malignancies in women, and the majority of cases are caused by infection with high-risk human papilloma virus (HPV) subtypes. Despite effective preventative measures, such as vaccinations against HPV, over 300,000 women die world-wide from cervical cancer each year. Once cervical cancer is diagnosed, treatment may consist of radial hysterectomy, or chemotherapy and radiotherapy, or a combination of therapies dependent upon the disease stage. Unfortunately, overall prognosis for patients with metastatic or recurrent disease remains poor. In these cases, immunotherapies may be useful based on promising preclinical work, some of which has been successfully translated to the clinic. For example, approaches using monoclonal antibodies directed against surface proteins important for control of immune checkpoints (i.e., immune checkpoint inhibitors) were shown to improve outcome in many cancer settings, including cervical cancer. Additionally, initial clinical studies showed that application of cytotoxic immune cells modified to express chimeric antigen receptors (CAR) or T cell receptors (TCR) for better recognition and elimination of tumor cells may be useful to control cervical cancer. This review explores these important topics, including strengths and limitations of standard and developing approaches, and how some novel treatment strategies may be optimally used to offer the best possible treatment for cervical cancer patients.

Exploiting the immunogenic potential of standard of care radiation or cisplatin therapy in preclinical models of HPV-associated malignancies

BACKGROUND

While radiation and chemotherapy are primarily purposed for their cytotoxic effects, a growing body of preclinical and clinical evidence demonstrates an immunogenic potential for these standard therapies. Accordingly, we sought to characterize the immunogenic potential of radiation and cisplatin in human tumor models of HPV-associated malignancies. These studies may inform rational combination immuno-oncology (IO) strategies to be employed in the clinic on the backbone of standard of care, and in so doing exploit the immunogenic potential of standard of care to improve durable responses in HPV-associated malignancies.

METHODS

Retroviral transduction with HPV16 E7 established a novel HPV-associated sinonasal squamous cell carcinoma (SNSCC) cell line. Three established HPV16-positive cell lines were also studied (cervical carcinoma and head and neck squamous cell carcinoma). Following determination of sensitivities to standard therapies using MTT assays, flow cytometry was used to characterize induction of immunogenic cell stress following sublethal exposure to radiation or cisplatin, and the functional consequence of this induction was determined using impedance-based real time cell analysis cytotoxicity assays employing HPV16 E7-specific cytotoxic lymphocytes (CTLs) with or without N803 (IL-15/IL-15-Rα superagonist) or exogenous death receptor ligands. In vitro observations were translated using an in vivo xenograft NSG mouse model of human cervical carcinoma evaluating cisplatin in combination with CTL adoptive cell transfer.

RESULTS

We showed that subpopulations surviving clinically relevant doses of radiation or cisplatin therapy were more susceptible to CTL-mediated lysis in four of four tumor models of HPV-associated malignancies, serving as a model for HPV therapeutic vaccine or T-cell receptor adoptive cell transfer. This increased killing was further amplified by IL-15 agonism employing N803. We further characterized that radiation or cisplatin induced immunogenic cell stress in three of three cell lines, and consequently demonstrated that upregulated surface expression of Fas and TRAIL-R2 death receptors at least in part mediated enhanced CTL-mediated lysis. In vivo, cisplatin-induced immunogenic cell stress synergistically potentiated CTL-mediated tumor control in a human model of HPV-associated malignancy.

CONCLUSION

Standard of care radiation or cisplatin therapy induced immunogenic cell stress in preclinical models of HPV-associated malignancies, presenting an opportunity poised for exploitation by employing IO strategies in combination with standard of care.

Development of therapeutic vaccines for the treatment of diseases

Vaccines are one of the most effective medical interventions to combat newly emerging and re-emerging diseases. Prophylactic vaccines against rabies, measles, etc., have excellent effectiveness in preventing viral infection and associated diseases. However, the host immune response is unable to inhibit virus replication or eradicate established diseases in most infected people. Therapeutic vaccines, expressing specific endogenous or exogenous antigens, mainly induce or boost cell-mediated immunity via provoking cytotoxic T cells or elicit humoral immunity via activating B cells to produce specific antibodies. The ultimate aim of a therapeutic vaccine is to reshape the host immunity for eradicating a disease and establishing lasting memory. Therefore, therapeutic vaccines have been developed for the treatment of some infectious diseases and chronic noncommunicable diseases. Various technological strategies have been implemented for the development of therapeutic vaccines, including molecular-based vaccines (peptide/protein, DNA and mRNA vaccines), vector-based vaccines (bacterial vector vaccines, viral vector vaccines and yeast-based vaccines) and cell-based vaccines (dendritic cell vaccines and genetically modified cell vaccines) as well as combinatorial approaches. This review mainly summarizes therapeutic vaccine-induced immunity and describes the development and status of multiple types of therapeutic vaccines against infectious diseases, such as those caused by HPV, HBV, HIV, HCV, and SARS-CoV-2, and chronic noncommunicable diseases, including cancer, hypertension, Alzheimer's disease, amyotrophic lateral sclerosis, diabetes, and dyslipidemia, that have been evaluated in recent preclinical and clinical studies.

Current progress in the development of prophylactic and therapeutic vaccines

Vaccines are essential public health tools and play an important role in reducing the burden of infectious diseases in the population. Emerging infectious diseases and outbreaks pose new challenges for vaccine development, requiring the rapid design and production of safe and effective vaccines against diseases with limited resources. Here, we focus on the development of vaccines in broad fields ranging from conventional prophylactic vaccines against infectious diseases to therapeutic vaccines against chronic diseases and cancer providing a comprehensive overview of recent advances in eight different vaccine forms (live attenuated vaccines, inactivated vaccines, polysaccharide and polysaccharide conjugate vaccines, recombinant subunit vaccines, virus-like particle and nanoparticle vaccines, polypeptide vaccines, DNA vaccines, and mRNA vaccines) and the therapeutic vaccines against five solid tumors (lung cancer breast cancer colorectal cancer liver cancer and gastric cancer), three infectious diseases (human immunodeficiency virus, hepatitis B virus and human papillomavirus-induced diseases) and three common chronic diseases (hypertension, diabetes mellitus and dyslipidemia). We aim to provide new insights into vaccine technologies, platforms, applications and understanding of potential next-generation preventive and therapeutic vaccine technologies paving the way for the vaccines design in the future.

Human Papillomavirus: Challenges and Opportunities for the Control of Cervical Cancer

Viruses are the most abundant and genetically diverse entities on the planet, infect all life forms and have evolved with their hosts. To date, 263 viral species have been identified that infect humans, of which only seven are considered type I oncogenic. Human papillomavirus (HPV) is the main virus associated with cancer and is responsible for practically all cases of cervical carcinoma. Screening tests for early detection have been available since the 1960s. Undoubtedly, the entailment between knowledge of HPV biology and the natural history of cervical cancer has contributed to the significant advances that have been made for its prevention since the 21^st century, with the development of prophylactic vaccines and improved screening strategies. Therefore, it is possible to eradicate invasive cervical cancer as a worldwide public health problem, as proposed by the WHO with the 90-70-90 initiative based on vaccination coverage, screening, and treatment, respectively. In addition, the emerging knowledge of viral biology generates opportunities that will contribute to strengthening prevention and treatment strategies in HPV-associated neoplasms.

Enhancing the Effect of Nucleic Acid Vaccines in the Treatment of HPV-Related Cancers: An Overview of Delivery Systems

Prophylactic vaccines against human papillomavirus (HPV) have proven efficacy in those who have not been infected by the virus. However, they do not benefit patients with established tumors. Therefore, the development of therapeutic options for HPV-related malignancies is critical. Third-generation vaccines based on nucleic acids are fast and simple approaches to eliciting adaptive immune responses. However, techniques to boost immunogenicity, reduce degradation, and facilitate their capture by immune cells are frequently required. One option to overcome this constraint is to employ delivery systems that allow selective antigen absorption and help modulate the immune response. This review aimed to discuss the influence of these different systems on the response generated by nucleic acid vaccines. The results indicate that delivery systems based on lipids, polymers, and microorganisms such as yeasts can be used to ensure the stability and transport of nucleic acid vaccines to their respective protein synthesis compartments. Thus, in view of the limitations of nucleic acid-based vaccines, it is important to consider the type of delivery system to be used-due to its impact on the immune response and desired final effect.

A Therapeutic Antigen-Presenting Cell-Targeting DNA Vaccine VB10.16 in HPV16-Positive High-Grade Cervical Intraepithelial Neoplasia: Results from a Phase I/IIa Trial

PURPOSE

To evaluate the safety, immunogenicity and efficacy of a therapeutic DNA vaccine VB10.16, using a unique modular vaccine technology that is based on linking antigens to CCL3L1 targeting module, in women with HPV16-positive high-grade cervical intraepithelial neoplasia (CIN).

PATIENTS AND METHODS

We conducted a first-in-human, open-label, phase I/IIa clinical trial of VB10.16 in subjects with confirmed HPV16-positive CIN 2/3. The primary endpoint was the proportion of participants with adverse events, including dose-limiting toxicities. Secondary outcome measures included measuring the E6/E7-specific cellular immune response. In the Expansion cohort HPV16 clearance, regression of CIN lesion size and grading were assessed during a 12-month follow-up period.

RESULTS

A total of 34 women were enrolled: 16 in two dose cohorts and 18 in the expansion cohort. No serious adverse events or dose-limiting toxicities were observed, and none of the subjects discontinued treatment with VB10.16 due to an adverse event. Mild to moderate injection site reactions were the most commonly reported adverse event (79%). HPV16-specific T-cell responses were observed after vaccination in the majority of the subjects. In the expansion cohort, HPV16 clearance was seen in 8 of 17 evaluable subjects (47%). Reductions in lesion size were seen in 16 subjects (94%) and 10 subjects (59%) had regression to CIN 0/1. Correlation between strong IFNγ T-cell responses and lesion size reduction was statistically significant (P < 0.001).

CONCLUSIONS

The novel therapeutic DNA vaccine VB10.16 was well tolerated and showed promising evidence of efficacy and strong HPV16-specific T-cell responses in subjects with high-grade CIN.

Effects of hypoxia on antigen presentation and T cell-based immune recognition of HPV16-transformed cells

Attempts to develop a therapeutic vaccine against human papillomavirus (HPV)-induced malignancies have mostly not been clinically successful to date. One reason may be the hypoxic microenvironment present in most tumors, including cervical cancer. Hypoxia dysregulates the levels of human leukocyte antigen (HLA) class I molecules in different tumor entities, impacts the function of cytotoxic T cells, and leads to decreased protein levels of the oncoproteins E6 and E7 in HPV-transformed cells. Therefore, we investigated the effect of hypoxia on the presentation of HPV16 E6- and E7-derived epitopes in cervical cancer cells and its effect on epitope-specific T cell cytotoxicity. Hypoxia induced downregulation of E7 protein levels in all analyzed cell lines, as assessed by Western blotting. However, contrary to previous reports, no perturbation of antigen processing and presentation machinery (APM) components and HLA-A2 surface expression upon hypoxia treatment was detected by mass spectrometry and flow cytometry, respectively. Cytotoxicity assays performed in hypoxic conditions showed differential effects on the specific killing of HPV16-positive cervical cancer cells by epitope-specific CD8+ T cell lines in a donor- and peptide-specific manner. Effects of hypoxia on the expression of PD-L1 were ruled out by flow cytometry analysis. Altogether, our results under hypoxia show a decreased expression of E6 and E7, but an intact APM, and epitope- and donor-dependent effects on T cell cytotoxicity towards HPV16-positive target cells. This suggests that successful immunotherapies can be developed for hypoxic HPV-induced cervical cancer, with careful choice of target epitopes, and ideally in combination with hypoxia-alleviating measures.

Gene Expression and DNA Methylation in Human Papillomavirus Positive and Negative Head and Neck Squamous Cell Carcinomas

High-risk human papillomaviruses (HPV) are important agents, responsible for a large percentage of the 745,000 cases of head and neck squamous cell carcinomas (HNSCC), which were identified worldwide in 2020. In addition to being virally induced, tobacco and heavy alcohol consumption are believed to cause DNA damage contributing to the high number of HNSCC cases. Gene expression and DNA methylation differ between HNSCC based on HPV status. We used publicly available gene expression and DNA methylation profiles from the Cancer Genome Atlas and compared HPV positive and HPV negative HNSCC groups. We used differential gene expression analysis, differential methylation analysis, and a combination of these two analyses to identify the differences. Differential expression analysis identified 1854 differentially expressed genes, including PCNA, TNFRSF14, TRAF1, TRAF2, BCL2, and BIRC3. SYCP2 was identified as one of the top deregulated genes in the differential methylation analysis and in the combined differential expression and methylation analyses. Additionally, pathway and ontology analyses identified the extracellular matrix and receptor interaction pathway as the most altered between HPV negative and HPV positive HNSCC groups. Combining gene expression and DNA methylation can help in elucidating the genes involved in HPV positive HNSCC tumorigenesis, such as SYCP2 and TAF7L.

Review Article: Immune Landscape and Immunotherapy Options in Cervical Carcinoma

Simple Summary

Cervical cancer is one of the most common cancers with a high mortality rate, especially in women of reproductive age. A lot of treatment modalities are being used in clinical practice but they come with a wide range of toxic side effects, the relapse of cancer, and a low disease-free survival rate. Immunotherapy has revolutionized the treatment landscape of cervical cancer as it focuses majorly on agents that stimulate the body’s own immune system against tumor cells. A deeper understanding of immune system players and immune perturbations in the onset and progression of cervical cancer can pave the way to better treatment with zero relapse. Immunotherapy holds the key to a cancer-free future. This review summarizes the immune players that are perturbed in cervical cancer, and immunotherapy options that are being exploited, alone or in combination, for the treatment of cervical carcinoma in women.

Abstract

Carcinoma of the cervix is one of the most common cancers that claims women’s lives every year. Despite preventive HPV vaccines and conventional cancer treatments, approximately 273,000 women succumb to cervical carcinoma every year. Immune system perturbations help malignant cells in immune evasion, tumor establishment, invasion, and metastasis. An insight into immune system players that promote or suppress cervical cancer is important for the development of more targeted therapies with the fewest side effects. Immunotherapy has emerged as the most compliant approach to target cancer because it utilizes a natural course of action to stimulate the immune system against cancer cells. The major immunotherapy approaches for cervical carcinoma include monoclonal antibodies, immune checkpoint blockade therapy, adoptive cell transfer therapies, and oncolytic viruses. In October 2021 the FDA approved pembrolizumab in combination with chemotherapy or bevacizumab as a first-line treatment for cervical cancer. A recent breakthrough has been made in the cancer immunotherapy regimen in which a monoclonal antibody dostarlimab was able to completely cure all colorectal cancer patients, with disease-free progression after 6 months and counting. This creates hope that immunotherapy may prove to be the final nail in the coffin of this centuries-long prevalent disease of “cancer”.

Governing HPV-related carcinoma using vaccines: Bottlenecks and breakthroughs

Human papillomavirus (HPV) contributes to sexually transmitted infection, which is primarily associated with pre-cancerous and cancerous lesions in both men and women and is among the neglected cancerous infections in the world. At global level, two-, four-, and nine-valent pure L1 protein encompassed vaccines in targeting high-risk HPV strains using recombinant DNA technology are available. Therapeutic vaccines are produced by early and late oncoproteins that impart superior cell immunity to preventive vaccines that are under investigation. In the current review, we have not only discussed the clinical significance and importance of both preventive and therapeutic vaccines but also highlighted their dosage and mode of administration. This review is novel in its way and will pave the way for researchers to address the challenges posed by HPV-based vaccines at the present time.

Can Adjuvant HPV Vaccination Be Helpful in the Prevention of Persistent/Recurrent Cervical Dysplasia after Surgical Treatment?—A Literature Review

Simple Summary

Primary prophylactic, early detection and the treatment of precancerous lesions are the main goals of cervical cancer screening. Despite effective surgical treatment methods, using loop electrosurgical excision procedures and conization, the overall risk of the recurrence of HSIL lesions remains at approximately 6.6%. There is increasing evidence of the potential role of HPV vaccines in the adjuvant setting and their impact on the reduction of disease recurrence. This review aims to analyze the up-to-date research concerning the use and efficacy of secondary human papilloma virus (HPV) vaccination as an adjuvant method to surgical treatment in patients diagnosed with cervical HSILs.

Abstract

Cervical cancer formation is preceded by precursor lesions, including low-grade squamous intraepithelial lesions (LSILs) and high-grade squamous intraepithelial lesions (HSILs), which are usually diagnosed in women of reproductive age. Despite the recent advanced diagnostic and treatment methods, including colposcopy, the loop electrosurgical excision procedure (LEEP), and surgical conization, the recurrence or residual disease affects as many as 6.6% of patients. The lesions are often associated with human papilloma virus (HPV) infection. As HPV persistence is the leading and only modifiable factor affecting the risk of progression of CIN lesions into high-grade cervical dysplasia and cancer, it has been proposed to conduct adjuvant vaccination in patients treated for high-grade cervical dysplasia. To date, no vaccine has been approved for therapeutic use in patients diagnosed with HSILs; however, attempts have been made to determine the use of HPV prophylactic vaccination to reduce recurrent HSILs and prevent cervical cancer. The aim of this review was to analyze the up-to-date literature concerning the possible use of secondary human papilloma virus (HPV) vaccination as an adjuvant method to surgical treatment in patients diagnosed with cervical HSILs. Adjuvant HPV vaccination after surgical treatment may reduce the risk of recurrent cervical dysplasia.

Investigation of the Optimal Prime Boost Spacing Regimen for a Cancer Therapeutic Vaccine Targeting Human Papillomavirus

Therapeutic vaccine studies should be designed to elicit durable, high magnitude, and efficacious T cell responses, all of which can be impacted by the choice of the vaccination schedule. Here, we compare different prime-boost intervals (PBI) in a human papillomavirus (HPV) model using a HPV16E7E6 Venezuelan equine encephalitis virus replicon particle (VRP) vaccination to address the optimal boosting schedule, quality of immune response, and overall in vivo efficacy. Six different vaccine regimens were tested with each group receiving booster vaccinations at different time intervals. Analysis of T-cell responses demonstrated a significant HPV16 E7 specific CD8+ T cell response with at minimum a one-week PBI between antigen re-exposure. Significant E7-specific in vivo cytotoxicity was also observed with longer PBIs. Additionally, longer PBIs led to an enhanced memory recall response to tumor challenge, which correlated with differential expansion of T cell memory subsets. Our findings imply that when using alphavirus vector platforms as a vaccination strategy, a one-week PBI is sufficient to induce high magnitude effector T cells with potent anti-tumor activity. However, longer PBIs lead to enhanced long-term protective anti-tumor immunity. These findings have implications for therapeutic vaccine clinical trials in which shorter intervals of prime-boost regimens may lead to suboptimal durable immune responses.

Virus-like particle vaccinology, from bench to bedside

Virus-like particles (VLPs) have become key tools in biology, medicine and even engineering. After their initial use to resolve viral structures at the atomic level, VLPs were rapidly harnessed to develop antiviral vaccines followed by their use as display platforms to generate any kind of vaccine. Most recently, VLPs have been employed as nanomachines to deliver pharmaceutically active products to specific sites and into specific cells in the body. Here, we focus on the use of VLPs for the development of vaccines with broad fields of indications ranging from classical vaccines against viruses to therapeutic vaccines against chronic inflammation, pain, allergy and cancer. In this review, we take a walk through time, starting with the latest developments in experimental preclinical VLP-based vaccines and ending with marketed vaccines, which earn billions of dollars every year, paving the way for the next wave of prophylactic and therapeutic vaccines already visible on the horizon.

Preclinical and clinical studies of bintrafusp alfa, a novel bifunctional anti-PD-L1/TGFβRII agent: Current status

Bintrafusp alfa (anti-PD-L1/TGFβRII) is a first-in-class bifunctional agent designed to act both as a checkpoint inhibitor and as a "trap" for TGFβ in the tumor microenvironment (TME). This article is designed to review the preclinical studies interrogating the mode of action of bintrafusp alfa and to present a comprehensive overview of recent bintrafusp alfa clinical studies. Preclinical studies have demonstrated that bintrafusp alfa immune-mediating and antitumor activity can be enhanced by combining it with a human papillomavirus (HPV) therapeutic cancer vaccine, a tumor-targeting interleukin 12 (IL-12) immunocytokine and/or an IL-15 superagonist. The importance of TGFβ in HPV-associated malignancies is also reviewed. The clinical studies reviewed span extended phase I cohorts in patients with a spectrum of malignancies, two randomized phase II studies in lung and one in biliary tract cancers in which bintrafusp alfa did not demonstrate superiority over standard-of-care therapies, and provocative results in patients with HPV-associated malignancies, where as a monotherapy, bintrafusp alfa has shown response rates of 35%, compared to overall response rate (ORR) of 12-24% seen with other Food and Drug Administration (FDA)-approved or standard-of-care agents. This article also reviews preliminary phase II study results of patients with HPV+ malignancies employing bintrafusp alfa in combination with an HPV therapeutic vaccine and a tumor-targeting IL-12 immunocytokine in which the combination therapy outperforms standard-of-care therapies in both checkpoint naïve and checkpoint refractory patients. This review thus provides an example of the importance of conducting clinical studies in an appropriate patient population - in this case, exemplified by the role of TGFβ in HPV-associated malignancies. This review also provides preclinical and preliminary clinical study results of the combined use of multiple immune-modulating agents, each designed to engage different immune components and tumor cells in the TME.

Glycoconjugate Nanoparticle-Based Systems in Cancer Immunotherapy: Novel Designs and Recent Updates

For many years, cell-surface glycans (in particular, Tumor-Associated Carbohydrate Antigens, TACAs) have been the target of both passive and active anticancer immunotherapeutic design. Recent advances in immunotherapy as a treatment for a variety of malignancies has revolutionized anti-tumor treatment regimens. Checkpoint inhibitors, Chimeric Antigen Receptor T-cells, Oncolytic virus therapy, monoclonal antibodies and vaccines have been developed and many approvals have led to remarkable outcomes in a subset of patients. However, many of these therapies are very selective for specific patient populations and hence the search for improved therapeutics and refinement of techniques for delivery are ongoing and fervent research areas. Most of these agents are directed at protein/peptide epitopes, but glycans–based targets are gaining in popularity, and a handful of approved immunotherapies owe their activity to oligosaccharide targets. In addition, nanotechnology and nanoparticle-derived systems can help improve the delivery of these agents to specific organs and cell types based on tumor-selective approaches. This review will first outline some of the historical beginnings of this research area and subsequently concentrate on the last 5 years of work. Based on the progress in therapeutic design, predictions can be made as to what the future holds for increasing the percentage of positive patient outcomes for optimized systems.

Immunotherapeutic Approaches for the Treatment of HPV-Associated (Pre-)Cancer of the Cervix, Vulva and Penis

Human papillomavirus (HPV) infection drives tumorigenesis in almost all cervical cancers and a fraction of vulvar and penile cancers. Due to increasing incidence and low vaccination rates, many will still have to face HPV-related morbidity and mortality in the upcoming years. Current treatment options (i.e., surgery and/or chemoradiation) for urogenital (pre-)malignancies can have profound psychosocial and psychosexual effects on patients. Moreover, in the setting of advanced disease, responses to current therapies remain poor and nondurable, highlighting the unmet need for novel therapies that prevent recurrent disease and improve clinical outcome. Immunotherapy can be a useful addition to the current therapeutic strategies in various settings of disease, offering relatively fewer adverse effects and potential improvement in survival. This review discusses immune evasion mechanisms accompanying HPV infection and HPV-related tumorigenesis and summarizes current immunotherapeutic approaches for the treatment of HPV-related (pre-)malignant lesions of the uterine cervix, vulva, and penis.

An Update on Human Papilloma Virus Vaccines: History, Types, Protection, and Efficacy

Human papillomavirus (HPV) is the most common sexually transmitted agent worldwide. Early prevention with HPV vaccination is a safe and effective method against this disease. HPV vaccines provided more protection against several oncogenic HPV strains. Three prophylactic HPV vaccines have been approved to target high-risk HPV types and protect against HPV-related disorders. These existing vaccines are based on the recombinant DNA technology and purified L1 protein that is assembled to form HPV empty shells. The prophylactic vaccines are highly immunogenic and can induce production of specific neutralizing antibodies. However, therapeutic vaccines are different from these prophylactic vaccines. They induced cell-mediated immunity against transformed cells, instead of neutralizing antibodies. The second generation of prophylactic HPV vaccines, made from alternative viral components using cost-effective production strategies, is undergoing clinical evaluation. The purpose of this review is to provide a complete and up-to-date review of the types of HPV vaccines and the efficiency of each of them for readers.

Therapeutic DNA Vaccines against HPV-Related Malignancies: Promising Leads from Clinical Trials

In 2014 and 2021, two nucleic-acid vaccine candidates named MAV E2 and VGX-3100 completed phase III clinical trials in Mexico and U.S., respectively, for patients with human papillomavirus (HPV)-related, high-grade squamous intraepithelial lesions (HSIL). These well-tolerated but still unlicensed vaccines encode distinct HPV antigens (E2 versus E6+E7) to elicit cell-mediated immune responses; their clinical efficacy, as measured by HSIL regression or cure, was modest when compared with placebo or surgery (conization), but both proved highly effective in clearing HPV infection, which should help further optimize strategies for enhancing vaccine immunogenicity, toward an ultimate goal of preventing malignancies in millions of patients who are living with persistent, oncogenic HPV infection but are not expected to benefit from current, prophylactic vaccines. The major roadblocks to a highly efficacious and practical product remain challenging and can be classified into five categories: (i) getting the vaccines into the right cells for efficient expression and presentation of HPV antigens (fusion proteins or epitopes); (ii) having adequate coverage of oncogenic HPV types, beyond the current focus on HPV-16 and -18; (iii) directing immune protection to various epithelial niches, especially anogenital mucosa and upper aerodigestive tract where HPV-transformed cells wreak havoc; (iv) establishing the time window and vaccination regimen, including dosage, interval and even combination therapy, for achieving maximum efficacy; and (v) validating therapeutic efficacy in patients with poor prognosis because of advanced, recurrent or non-resectable malignancies. Overall, the room for improvements is still large enough that continuing efforts for research and development will very likely extend into the next decade.

Efficacy and Safety of Immunotherapy for Cervical Cancer—A Systematic Review of Clinical Trials

Purpose: To systematically review the current body of evidence on the efficacy and safety of immunotherapy for cervical cancer (CC). Material and Methods: Medline, the Cochrane Central Register of Controlled Trials and Web of Science were searched for prospective trials assessing immunotherapy in CC patients in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Full-text articles in English and German reporting outcomes of survival, response rates or safety were eligible. Results: Of 4655 screened studies, 51 were included (immune checkpoint inhibitors (ICI) n=20; therapeutic vaccines n = 25; adoptive cell transfer therapy n=9). Of these, one qualified as a phase III randomized controlled trial and demonstrated increased overall survival following treatment with pembrolizumab, chemotherapy and bevacizumab. A minority of studies included a control group (n = 7) or more than 50 patients (n = 15). Overall, response rates were low to moderate. No response to ICIs was seen in PD-L1 negative patients. However, few remarkable results were achieved in heavily pretreated patients. There were no safety concerns in any of the included studies. Conclusion: Strong evidence on the efficacy of strategies to treat recurrent or metastatic cervical cancer is currently limited to pembrolizumab in combination with chemotherapy and bevacizumab, which substantiates an urgent need for large confirmatory trials on alternative immunotherapies. Overall, there is sound evidence on the safety of immunotherapy in CC.

Human Papillomavirus-Directed Therapeutics for Human Papillomavirus-Associated Oropharyngeal Cancer

ABSTRACT

Despite the availability of prophylactic human papillomavirus (HPV) vaccines, there is a growing incidence of HPV-associated head and neck squamous cell carcinomas (HPV-HNSCC) worldwide. The viral etiology of HPV-HNSCC provides an opportunity to develop personalized immune-based therapies, which target the unique viral- or tumor-specific proteins. Novel HPV-targeted immunotherapeutic approaches in clinical development are reviewed. Early results from these trials highlight new opportunities and potential challenges ahead. Immunotherapies for HPV-associated HNSCCs will require a tailored combinatorial approach based on preexisting mechanisms of host immune resistance. As the field continues to identify the relevant HPV types 16 and 18 immunogenic epitopes that are presented by diverse HLA class I alleles, improved HPV-targeted biologics and clinical monitoring tools can be developed and applied to a broader cancer patient population.

Immunotherapeutic approaches for HPV-caused cervical cancer

Cervical cancer, the fourth most frequent women cancer worldwide, is mostly (about 99%) associated with human papillomavirus (HPV). Despite availability of three effective prophylactic vaccines for more than one decade and some other preventive measures, it is still the fourth cause of cancer death among women globally. Thus, development of therapeutic vaccines seems essential, which has been vastly studied using different vaccine platforms. Even with very wide efforts during the past years, no therapeutic vaccine has been approved yet, which might be partly due to the complex events and interactions taken place in the tumor microenvironment. On the other hand, immunotherapy has opened its way into the management plans of some cancers. The recent approval of pembrolizumab for the treatment of metastatic/recurrent cervical cancer brings new hopes to the management of this disease, while some other immunotherapeutic approaches are also under investigation either alone or in combination with vaccines. Here, following a summary about HPV and its pathogenesis, cervical cancer therapeutic vaccines would be reviewed. Cell-based vaccines as well as immunomodulation and other modalities used along with vaccines would be also discussed.

Transition metal-catalysed A-ring C-H activations and C(sp2)-C(sp2) couplings in the 13α-oestrone series and in vitro evaluation of antiproliferative properties

Facile syntheses of 3-O-carbamoyl, -sulfamoyl, or -pivaloyl derivatives of 13α-oestrone and its 17-deoxy counterpart have been carried out. Microwave-induced, Ni-catalysed Suzuki-Miyaura couplings of the newly synthesised phenol esters with phenylboronic acid afforded 3-deoxy-3-phenyl-13α-oestrone derivatives. The carbamate and pivalate esters proved to be suitable for regioselective arylations. 2-(4-Substituted) phenyl derivatives were synthesised via Pd-catalysed, microwave-assisted C-H activation reactions. An efficient, one-pot, tandem methodology was elaborated for the introduction of the carbamoyl or pivaloyl group followed by regioselective C-2-arylation and subsequent removal of the directing group. The antiproliferative properties of the novel 13α-oestrone derivatives were evaluated in vitro on five human adherent cancer cell lines of gynaecological origin. 3-Sulfamate derivatives displayed substantial cell growth inhibitory potential against certain cell lines. The newly identified antiproliferative compounds having hormonally inactive core might be promising candidates for the design of more active anticancer agents.

Humanized Mice as a Valuable Pre-Clinical Model for Cancer Immunotherapy Research

Immunotherapy with checkpoint inhibitors opened new horizons in cancer treatment. Clinical trials for novel immunotherapies or unexplored combination regimens either need years of development or are simply impossible to perform like is the case in cancer patients with limited life expectancy. Thus, the need for preclinical models that rapidly and safely allow for a better understanding of underlying mechanisms, drug kinetics and toxicity leading to the selection of the best regimen to be translated into the clinic, is of high importance. Humanized mice that can bear both human immune system and human tumors, are increasingly used in recent preclinical immunotherapy studies and represent a remarkably unprecedented tool in this field. In this review, we describe, summarize, and discuss the recent advances of humanized mouse models used for cancer immunotherapy research and the challenges faced during their establishment. We also highlight the lack of preclinical studies using this model for radiotherapy-based research and argue that it can be a great asset to understand and answer many open questions around radiation therapy such as its presumed associated "abscopal effect".

Development and Characterization of a Novel Non-Lytic Cancer Immunotherapy Using a Recombinant Arenavirus Vector Platform

Engineered viral vectors represent a promising strategy to trigger antigen-specific antitumor T cell responses. Arenaviruses have been widely studied because of their ability to elicit potent and protective T cell responses. Here, we provide an overview of a novel intravenously administered, replication-competent, non-lytic arenavirus-based vector technology that delivers tumor antigens to induce antigen-specific anti-cancer T cell responses. Preclinical studies in mice and cell culture experiments with human peripheral blood mononuclear cells demonstrate that arenavirus vectors preferentially infect antigen-presenting cells. This, in conjunction with a non-lytic functional activation of the infected antigen-presenting cells, leads to a robust antigen-specific CD8⁺ T cell response. T cell migration to, and infiltration of, the tumor microenvironment has been demonstrated in various preclinical tumor models with vectors encoding self- and non-self-antigens. The available data also suggest that arenavirus-based vector therapy can induce immunological memory protecting from tumor rechallenge. Based on promising preclinical data, a phase 1/2 clinical trial was initiated and is currently ongoing to test the activity and safety of arenavirus vectors, HB-201 and HB-202, created using lymphocytic choriomeningitis virus and Pichinde virus, respectively. Both vectors have been engineered to deliver non-oncogenic versions of the human papilloma virus 16 (HPV16) antigens E7 and E6 and will be injected intravenously with or without an initial intratumoral dose. This dose escalation/expansion study is being conducted in patients with recurrent or metastatic HPV16+ cancers. Promising preliminary data from this ongoing clinical study have been reported. Immunogenicity data from several patients demonstrate that a single injection of HB-201 or HB-202 monotherapy is highly immunogenic, as evidenced by an increase in inflammatory cytokines/chemokines and the expansion of antigen-specific CD8⁺ T cell responses. This response can be further enhanced by alternating injections of HB-202 and HB-201, which has resulted in frequencies of circulating HPV16 E7/E6-specific CD8⁺ T cells of up to 40% of the total CD8⁺ T cell compartment in peripheral blood in analyses to date. Treatment with intravenous administration also resulted in a disease control rate of 73% among 11 evaluable patients with head and neck cancer dosed every three weeks, including 2 patients with a partial response.

The Key Differences between Human Papillomavirus-Positive and -Negative Head and Neck Cancers: Biological and Clinical Implications

Head and neck squamous cell carcinoma (HNSCC) is a unique malignancy associated with two distinct risk factors: exposure to typical carcinogens and infection of human papillomavirus (HPV). HPV encodes the potent oncoproteins E6 and E7, which bypass many important oncogenic processes and result in cancer development. In contrast, HPV-negative HNSCC is developed through multiple mutations in diverse oncogenic driver genes. While the risk factors associated with HPV-positive and HPV-negative HNSCCs are discrete, HNSCC patients still show highly complex molecular signatures, immune infiltrations, and treatment responses even within the same anatomical subtypes. Here, we summarize the current understanding of biological mechanisms, treatment approaches, and clinical outcomes in comparison between HPV-positive and -negative HNSCCs.

Targeting Human Papillomavirus-Associated Cancer by Oncoprotein-Specific Recombinant Antibodies

In recent decades, recombinant antibodies against specific antigens have shown great promise for the therapy of infectious diseases and cancer. Human papillomaviruses (HPVs) are involved in the development of around 5% of all human cancers and HPV16 is the high-risk genotype with the highest prevalence worldwide, playing a dominant role in all HPV-associated cancers. Here, we describe the main biological activities of the HPV16 E6, E7, and E5 oncoproteins, which are involved in the subversion of important regulatory pathways directly associated with all known hallmarks of cancer. We then review the state of art of the recombinant antibodies targeted to HPV oncoproteins developed so far in different formats, and outline their mechanisms of action. We describe the advantages of a possible antibody-based therapy against the HPV-associated lesions and discuss the critical issue of delivery to tumour cells, which must be addressed in order to achieve the desired translation of the antibodies from the laboratory to the clinic.

Oral epithelial dysplasia: Recognition, grading and clinical significance

Histopathological grading of epithelial dysplasia remains the principal laboratory method for assessing the risk of malignant transformation in oral potentially malignant disorders (OPMDs). Current views on the molecular pathogenesis and histological interpretation of the features of epithelial dysplasia are described, and the use of grading systems for epithelial dysplasia is discussed. Changes to the current 2017 WHO criteria for diagnosis are proposed with emphasis on the architectural features of epithelial dysplasia. The predictive values of three-grade and binary systems are summarised, and categories of epithelial dysplasia are reviewed, including lichenoid and verrucous lesions, keratosis of unknown significance, HPV-associated dysplasia, differentiated and basaloid epithelial dysplasia. The implications of finding epithelial dysplasia in an oral biopsy for clinical management are discussed from the pathologists' viewpoint.