Immunogenicity and safety of the human papillomavirus vaccine in young survivors of cancer in the USA: a single-arm, open-label, phase 2, non-inferiority trial.

BACKGROUND: Young survivors of cancer are at increased risk for cancers that are related to human papillomavirus (HPV), primarily caused by oncogenic HPV types 16 and 18. We aimed to examine the immunogenicity and safety of the three-dose series of HPV vaccine in young survivors of cancer. METHODS: We conducted an investigator-initiated, phase 2, single-arm, open-label, non-inferiority trial at five National Cancer Institute-designated comprehensive cancer centres in the USA. Eligible participants were survivors of cancer who were HPV vaccine-naive, were aged 9-26 years, in remission, and had completed cancer therapy between 1 and 5 years previously. Participants received three intramuscular doses of either quadrivalent HPV vaccine (HPV4; enrolments on or before March 1, 2016) or nonavalent HPV vaccine (HPV9; enrolments after March 1, 2016) over 6 months (on day 1, at month 2, and at month 6). We also obtained data from published clinical trials assessing safety and immunogenicity of HPV4 and HPV9 in 9-26-year-olds from the general population, as a comparator group. The primary endpoint was antibody response against HPV types 16 and 18 at month 7 in the per-protocol population. A response was deemed non-inferior if the lower bound of the multiplicity-adjusted 95% CI was greater than 0·5 for the ratio of anti-HPV-16 and anti-HPV-18 geometric mean titres (GMTs) in survivors of cancer versus the general population. Responses were examined separately in male and female participants by age group (ie, 9-15 years and 16-26 years). Safety was assessed in all participants who received at least one vaccine dose and for whom safety data were available. This study is registered with ClinicalTrials.gov, NCT01492582. This trial is now completed. FINDINGS: Between Feb 18, 2013, and June 22, 2018, we enrolled 453 survivors of cancer, of whom 436 received one or more vaccine doses: 203 (47%) participants had survived leukaemia, 185 (42%) were female, and 280 (64%) were non-Hispanic white. Mean age at first dose was 15·6 years (SD 4·6). 378 (83%) of 453 participants had evaluable immunogenicity data; main reasons for exclusion from per-protocol analysis were to loss to follow-up, patient reasons, and medical reasons. Data were also obtained from 26 486 general population controls. The ratio of mean GMT for anti-HPV types 16 and 18 in survivors of cancer versus the general population was more than 1 for all subgroups (ie, aged 9-15 years, aged 16-26 years, male, and female groups) in both vaccine cohorts (ranging from 1·64 [95% CI 1·12-2·18] for anti-HPV type 16 in female participants aged 9-15 years who received HPV9, to 4·77 [2·48-7·18] for anti-HPV type 18 in male participants aged 16-26 years who received HPV4). Non-inferiority criteria were met within each age and sex subgroup, except against HPV type 18 in female participants aged 16-26 years receiving HPV9 (4·30 [0·00-9·05]). Adverse events were reported by 237 (54%) of 435 participants; injection site pain was most common (174 [40%] participants). One serious adverse event (ie, erythema nodosum) was possibly related to vaccine (HPV9; 16-26 year female cohort). INTERPRETATION: Immunogenicity and safety of HPV vaccine three-dose series in survivors of cancer is similar to that in the general population, providing evidence for use in this clinically vulnerable population. FUNDING: US National Cancer Institute, Merck, Sharp & Dohme, and American Lebanese Syrian Associated Charities.

A Potential Herbal Adjuvant Combined With a Peptide-Based Vaccine Acts Against HPV-Related Tumors Through Enhancing Effector and Memory T-Cell Immune Responses.

Viral infection is associated with many types of tumorigenesis, including human papillomavirus (HPV)-induced cervical cancer. The induction of a specific T-cell response against virus-infected cells is desired to develop an efficient therapeutic approach for virus-associated cancer. Chinese herbal medicine (CHM) has a long history in the treatment of cancer patients in Asian countries. Hedyotis diffusa Willd (Bai Hua She She Cao, BHSSC) is frequently used clinically and has been shown to inhibit tumor growth in vitro. However, in vivo data demonstrating the antitumor efficacy of BHSSC are still lacking. We showed that BHSSC induces murine and human antigen-presenting cell (APC) activation via the MAPK signaling pathway and enhances antigen presentation in bone marrow-derived dendritic cells (BMDCs) in vitro. Furthermore, we identified that treatment with BHSSC leads to improved specific effector and memory T-cell responses in vivo. Variant peptide-based vaccines combined with BHSSC improved antitumor activity in preventive, therapeutic, and recurrent HPV-related tumor models. Furthermore, we showed that rutin, one of the ingredients in BHSSC, induces a strong specific immune response against HPV-related tumors in vivo. In summary, we demonstrated that BHSSC extract and its active compound, rutin, can be used as adjuvants in peptide-based vaccines to increase immunogenicity and to bypass the requirement of a conditional adjuvant.

Cervical Microbiome and Response to a Human Papillomavirus Therapeutic Vaccine for Treating High-Grade Cervical Squamous Intraepithelial Lesion.

Human papillomavirus (HPV) infection is associated with the vast majority of cervical cancer cases as well as with other anogenital cancers. PepCan is an investigational HPV therapeutic vaccine for treating cervical high-grade squamous intraepithelial lesions. The present study was performed to test whether the cervical microbiome influences vaccine responses and to explore host factors as determinants of the cervical microbiome composition in women with biopsy-proven high-grade squamous intraepithelial lesions. In a recently completed Phase I clinical trial of PepCan, histological response rate of 45% (14 of 31 patients), a significant increase in circulating T-helper type 1 cells, and a significant decrease in HPV 16 viral load were reported. DNA, extracted from liquid cytology specimens collected before and after vaccinations, were amplified and then hybridized to a G4 PhyloChip assay to characterize the microbiome. We describe trends that certain bacterial taxa in the cervix may be enriched in non-responders in comparison to responders (Padj = .052 for phylum Caldithrix and Padj = .059 for phylum Nitrospirae). There was no difference in bacterial diversity between the 2 groups. A permutational analysis of variance performed for various demographic and immune parameters showed significant clustering with microbiome beta diversity for race, HPV 16 status, peripheral T-helper type 1 cells, and HLA-B40 (P = .001, .014, .037, and .024, respectively). Further analyses showed significant differences at the empirical Operational Taxonomic Unit level for race and HPV 16 status. As these results are from a small Phase I study, further studies are needed to examine the role of cervical microbiome in response to HPV therapeutic vaccines.

A Novel Human Papillomavirus 16 L1 Pentamer-Loaded Hybrid Particles Vaccine System: Influence of Size on Immune Responses.

Cervical cancer remains the second-most prevalent female malignancy around the world, leading to a great majority of cancer-related mortality that occurs mainly in developing countries. Developing an effective and low-cost vaccine against human papillomavirus (HPV) infection, especially in medically underfunded areas, is urgent. Compared with vaccines based on HPV L1 viruslike particles (VLPs) in the market, recombinant HPV L1 pentamer expressed in Escherichia coli represents a promising and potentially cost-effective vaccine for preventing HPV infection. Hybrid particles comprising a polymer core and lipid shell have shown great potential compared to conventional aluminum salts adjuvant and is urgently needed for HPV L1 pentamer vaccines. It is well-reported that particle sizes are crucial in regulating immune responses. Nevertheless, reports on the relationship between the particulate size and the resultant immune response have been in conflict, and there is no answer to how the size of particles regulates specific immune response for HPV L1 pentamer-based candidate vaccines. Here, we fabricated HPV 16 L1 pentamer-loaded poly(d,l-lactide- co-glycolide) (PLGA)/lecithin hybrid particles with uniform sizes (0.3, 1, and 3 µm) and investigated the particle size effects on antigen release, activation of lymphocytes, dendritic cells (DCs) activation and maturation, follicular helper CD4+ T (TFH) cells differentiation, and release of pro-inflammatory cytokines and chemokines. Compared with the other particle sizes, 1 µm particles induced more powerful antibody protection and yielded more persistent antibody responses, as well as more heightened anamnestic responses upon repeat vaccination. The superior immune responses might be attributed to sustainable antigen release and robust antigen uptake and transport and then further promoted a series of cascade reactions, including enhanced DCs maturation, increased lymphocytes activation, and augmented TFH cells differentiation in draining lymph nodes (DLNs). Here, a powerful and economical platform for HPV vaccine and a comprehensive understanding of particle size effect on immune responses for HPV L1 pentamer-based candidate vaccines are provided.

Displaying 31RG-1 peptide on the surface of HPV16 L1 by use of a human papillomavirus chimeric virus-like particle induces cross-neutralizing antibody responses in mice.

Current available human papillomavirus (HPV) vaccines are based on the major capsid protein L1 virus-like particles (VLPs), which mainly induce type-specific neutralizing antibodies against vaccine types. Continuing to add more types of VLPs in a vaccine raises the complexity and cost of production which remains the principal impediment to achieve broad implementation of HPV vaccines, particularly in developing regions. In this study, we constructed 16L1-31L2 chimeric VLP (cVLP) by displaying HPV31 L2 aa.17-38 on the h4 coil surface region of HPV16 L1, and assessed its immunogenicity in mouse model. We found that the cVLP adjuvanted with alum plus monophosphoryl lipid A could induce cross-neutralizing antibody responses against 16 out of 17 tested HPV pseudoviruses, and the titer against HPV16 was as high as that was induced by HPV16 L1VLP (titer > 105), more importantly, titers over 103 were observed against two HR-HPVs including HPV31 (titer, 2,200) and -59 (titer, 1,013), among which HPV59 was not covered by Gardasil-9, and medium or low titers of cross-neutralizing antibodies against other 13 tested HPV pseudoviruses were also observed. Our data demonstrate that 16L1-31L2 cVLP is a promising candidate for the formulation of broader spectrum HPV vaccines.

Enhancement of therapeutic DNA vaccine potency by melatonin through inhibiting VEGF expression and induction of antitumor immunity mediated by CD8+ T cells.

To be effective, therapeutic cancer vaccines should stimulate both an effective cell-mediated and a robust cytotoxic CD8+ T-cell response against human papillomavirus (HPV)-infected cells to treat the pre-existing tumors and prevent potential future tumors. In this study, the therapeutic experiments were designed in order to evaluate antitumor effect against the syngeneic TC-1 tumor model. The anti-tumor efficacy of a HPV-16 E7 DNA vaccine adjuvanted with melatonin (MLT) was evaluated in a C57BL/6 mouse tumor model by measuring tumor growth post vaccination and the survival rate of tumor-bearing mice, analyzing the specific lymphocyte proliferation responses in control and vaccinated mice by MTT assay. The E7-specific cytotoxic T cells (CTL) were analyzed by lymphocyte proliferation and lactate dehydrogenates (LDH) release assays. IFN-γ, IL-4 and TNF-α secretion in splenocyte cultures as well as vascular endothelial growth factor (VEGF) and IL-10 in the tumor microenvironment were assayed by ELISA. Our results demonstrated that subcutaneous administration of C57BL/6 mice with a DNA vaccine adjuvanted with MLT dose-dependently and significantly induced strong HPV16 E7-specific CD8+ cytotoxicity and IFN-γ and TNF-α responses capable of reducing HPV-16 E7-expressing tumor volume. A significantly higher level of E7-specific T-cell proliferation was also found in the adjuvanted vaccine group. Furthermore, tumor growth was significantly inhibited when the DNA vaccine was combined with MLT and the survival time of TC-1 tumor bearing mice was also significantly prolonged. In vivo studies further demonstrated that MLT decreased the accumulation of IL-10 and VEGF in the tumor microenvironment of vaccinated mice. These data indicate that melatonin as an adjuvant augmented the cancer vaccine efficiency against HPV-associated tumors in a dose dependent manner.

HPV16 induces a wasting syndrome in transgenic mice: Amelioration by dietary polyphenols via NF-κB inhibition.

Cancer patients often show a wasting syndrome for which there are little therapeutic options. Dietary polyphenols have been proposed for treating this syndrome, but their usefulness in cases associated with human papillomavirus (HPV)-induced cancers is unknown. We characterized HPV16-transgenic mice as a model of cancer cachexia and tested the efficacy of long-term oral supplementation with polyphenols curcumin and rutin. Both compounds were orally administered to six weeks-old HPV16-transgenic mice showing characteristic multi-step skin carcinogenesis, for 24weeks. Skin lesions and blood, liver and spleen inflammatory changes were characterized histologically and hematologically. Hepatic oxidative stress, skeletal muscle mass and the levels of muscle pro-inflammatory transcription factor NF-κB were also assessed. Skin carcinogenesis was associated with progressive, severe, systemic inflammation (leukocytosis, hepatitis, splenitis), significant mortality and cachexia. Curcumin and rutin totally suppressed mortality while reducing white blood cells and the incidence of splenitis and hepatitis. Rutin prevented muscle wasting more effectively than curcumin. Preservation of muscle mass and reduced hepatic inflammation were associated with down-regulation of the NF-κB canonical pathway and with reduced oxidative stress, respectively. These results point out HPV16-transgenic mice as a useful model for studying the wasting syndrome associated with HPV-induced cancers. Dietary NF-κB inhibitors may be useful resources for treating this syndrome.

Non-clinical safety assessment of single and repeated intramuscular administration of a human papillomavirus-16/18 vaccine in rabbits and rats.

The human papillomavirus (HPV)-16/18 vaccine (Cervarix®) is a prophylactic vaccine for the prevention of cervical cancer. The vaccine contains recombinant virus-like particles assembled from the L1 major capsid proteins of the cervical cancer-causing viral types HPV-16 and HPV-18, and Adjuvant System 04 (AS04), which contains the immunostimulant MPL and aluminium salt. To evaluate potential local and systemic toxic effects of the HPV-16/18 vaccine or AS04 alone, three repeated-dose studies were performed in rabbits and rats. One rabbit study also included a single-dose evaluation. In rabbits (~2.5 kg), the full human dose (HD) of the vaccine was evaluated (0.5 ml per injection site), and in rats (~250 g), 1/5 HD of vaccine was evaluated, corresponding to ≥ 12 times the dosage in humans relative to body weight. In both animal models, the treatment-related changes included a slight transient increase in the number of circulating neutrophils as well as a local inflammatory reaction at the injection site. These treatment-related changes were less pronounced after four doses of AS04 alone than after four doses of the HPV-16/18 vaccine. Additional treatment-related changes in the rat included lower albumin/globulin ratios and microscopic signs of inflammation in the popliteal lymph nodes. In both animal models, 13 weeks after the fourth dose, recovery was nearly complete, although at the injection site in some animals there were signs of discoloration, muscle-fibre regeneration and focal points of macrophage infiltration. Therefore, in these non-clinical models, the single and repeated dose administrations of the HPV-16/18 vaccine or AS04 alone were safe and well tolerated.

Polymeric nanoparticles for co-delivery of synthetic long peptide antigen and poly IC as therapeutic cancer vaccine formulation.

The aim of the current study was to develop a cancer vaccine formulation for treatment of human papillomavirus (HPV)-induced malignancies. Synthetic long peptides (SLPs) derived from HPV16 E6 and E7 oncoproteins have been used for therapeutic vaccination in clinical trials with promising results. In preclinical and clinical studies adjuvants based on mineral oils (such as incomplete Freund's adjuvant (IFA) and Montanide) are used to create a sustained release depot at the injection site. While the depot effect of mineral oils is important for induction of robust immune responses, their administration is accompanied with severe adverse and long lasting side effects. In order to develop an alternative for IFA family of adjuvants, polymeric nanoparticles (NPs) based on hydrophilic polyester (poly(d,l lactic-co-hydroxymethyl glycolic acid) (pLHMGA)) were prepared. These NPs were loaded with a synthetic long peptide (SLP) derived from HPV16 E7 oncoprotein and a toll like receptor 3 (TLR3) ligand (poly IC) by double emulsion solvent evaporation technique. The therapeutic efficacy of the nanoparticulate formulations was compared to that of HPV SLP+poly IC formulated in IFA. Encapsulation of HPV SLP antigen in NPs substantially enhanced the population of HPV-specific CD8+ T cells when combined with poly IC either co-encapsulated with the antigen or in its soluble form. The therapeutic efficacy of NPs containing poly IC in tumor eradication was equivalent to that of the IFA formulation. Importantly, administration of pLHMGA nanoparticles was not associated with adverse effects and therefore these biodegradable nanoparticles are excellent substitutes for IFA in cancer vaccines.

Treatment of established lesions caused by high-risk human papilloma virus using a synthetic vaccine.

Here, we review a novel vaccine modality, characterized by the administration of long (23 to 45 amino acids) synthetic peptides in incomplete Freund's adjuvant (mineral oil based, Montanide ISA-51), delivered subcutaneously. Such vaccines were first demonstrated to be much more potent in preclinical T-cell response induction and tumor therapy experiments than were short major histocompatibility complex class I-binding peptides. Nevertheless, a recent study has shown the clinical efficacy of an anchor-modified short gp100 peptide in melanoma patients. We now review the evidence and mode of action of a long peptide vaccine consisting of 13 overlapping peptides, together covering the entire length of the 2 oncogenic proteins E6 and E7 of high-risk human papilloma virus type 16 (HPV16), causing complete regression of all lesions and eradicating virus in 9 of 20 women with high-grade vulvar intraepithelial neoplasia. The nature and strength of the vaccine-induced T-cell response correlated significantly with the clinical response. This vaccine promises to be of use not only in patients with premalignant lesions caused by high-risk HPV16 but also in malignant tumors caused by this virus, including HPV16-positive cervical cancer, vulvar cancer, anal cancer, and head and neck cancer.

Treatment with imiquimod enhances antitumor immunity induced by therapeutic HPV DNA vaccination.

BACKGROUND: There is an urgent need to develop new innovative therapies for the control of advanced cancer. The combination of antigen-specific immunotherapy with the employment of immunomodulatory agents has emerged as a potentially plausible approach for the control of advanced cancer. METHODS: In the current study, we explored the combination of the DNA vaccine encoding calreticulin (CRT) linked to human papillomavirus type 16 (HPV-16) E7 antigen (CRT/E7) with the TLR7 agonist imiquimod for their ability to generate E7-specific immune responses and antitumor effects in tumor-bearing mice. RESULTS: We observed that treatment with CRT/E7 DNA in combination with imiquimod leads to an enhancement in the E7-specific CD8+ T cell immune responses and a decrease in the number of myeloid-derived suppressor cells in the tumor microenvironment of tumor-bearing mice. Furthermore, treatment with CRT/E7 DNA in combination with imiquimod leads to significantly improved antitumor effects and prolonged survival in treated mice. In addition, treatment with imiquimod led to increased number of NK1.1+ cells and F4/80+ cells in the tumor microenvironment. Macrophages and NK1.1+ cells were found to play an important role in the antitumor effects mediated by treatment with CRT/E7 DNA in combination with imiquimod. CONCLUSIONS: Thus, our data suggests that the combination of therapeutic HPV DNA vaccination with topical treatment with the TLR7 agonist imiquimod enhances the antitumor immunity induced by DNA vaccination. The current study has significant implications for future clinical translation.

Effect of alternative aluminum adjuvants on the absorption and immunogenicity of HPV16 L1 VLPs in mice.

Aluminum adjuvants are commonly used in prophylactic vaccines to enhance antigen immunogenicity through induction of high-titer antibody responses. Three major forms of aluminum adjuvants with substantially different physical and chemical properties have been described: aluminum phosphate (AlPO(4)), aluminum hydroxide (AlOH) and amorphous aluminum hydroxyphosphate sulfate (AAHS). Here we describe the effect of these different aluminum adjuvants on the formulation and subsequent immunogenicity in mice of virus-like particles (VLPs) consisting of the L1 protein of Human Papillomavirus (HPV) Type 16. Electron microscopy demonstrated that the physical appearance of the phosphate-containing aluminum adjuvants was markedly different from that of aluminum hydroxide. All three aluminum adjuvants were found to display unique surface charge profiles over a range of pH, while AAHS demonstrated the greatest inherent capacity for adsorption of L1 VLPs. These differences were associated with differences in immunogenicity: anti-HPV L1 VLP responses from mice immunized with AAHS-formulated HPV16 vaccine were substantially greater than those produced by mice immunized with the same antigen formulated with aluminum hydroxide. In addition, HPV L1 VLPs formulated on AAHS also induced a substantial interferon-gamma secreting T cell response to L1 peptides indicating the potential for an enhanced memory response to this antigen. These results indicate that the chemical composition of aluminum adjuvants can have a profound influence on the magnitude and quality of the immune response to HPV VLP vaccines.