Treatment failure in patients with HPV 16-induced vulvar intraepithelial neoplasia: understanding different clinical responses to immunotherapy

Importance of the Immune Microenvironment in the Spontaneous Regression of Cervical Squamous Intraepithelial Lesions (cSIL) and Implications for Immunotherapy

Cervical high-grade squamous intraepithelial lesions (cHSILs) develop as a result of a persistent high-risk human papilloma virus (hrHPV) infection. The natural course of cHSIL is hard to predict, depending on a multitude of viral, clinical, and immunological factors. Local immunity is pivotal in the pathogenesis, spontaneous regression, and progression of cervical dysplasia; however, the underlying mechanisms are unknown. The aim of this review is to outline the changes in the immune microenvironment in spontaneous regression, persistence, and responses to (immuno)therapy. In lesion persistence and progression, the immune microenvironment of cHSIL is characterized by a lack of intraepithelial CD3+, CD4+, and CD8+ T cell infiltrates and Langerhans cells compared to the normal epithelium and by an increased number of CD25+FoxP3+ regulatory T cells (Tregs) and CD163+ M2 macrophages. Spontaneous regression is characterized by low numbers of Tregs, more intraepithelial CD8+ T cells, and a high CD4+/CD25+ T cell ratio. A ‘hot’ immune microenvironment appears to be essential for spontaneous regression of cHSIL. Moreover, immunotherapy, such as imiquimod and therapeutic HPV vaccination, may enhance a preexisting pro-inflammatory immune environment contributing to lesion regression. The preexisting immune composition may reflect the potential for lesion regression, leading to a possible immune biomarker for immunotherapy in cHSILs.

Tumour virus vaccines: hepatitis B virus and human papillomavirus

Two of the most important human oncogenic viruses are hepatitis B virus (HBV) and human papillomavirus (HPV). HBV infection has been preventable by vaccination since 1982; vaccination of neonates and infants is highly effective, resulting already in decreased rates of new infections, chronic liver disease and hepato-cellular carcinoma. Nonetheless, HBV remains a global public health problem with high rates of vertical transmission from mother to child in some regions. Prophylactic HPV vaccines composed of virus-like particles (VLPs) of the L1 capsid protein have been licensed since 2006/2007. These target infection by the oncogenic HPVs 16 and 18 (the cause of 70% of cervical cancers); a new vaccine licensed in 2014/2015 additionally targets HPVs 31, 33, 45, 52, 58. HPV vaccines are now included in the national immunization programmes in many countries, with young adolescent peri-pubertal girls the usual cohort for immunization. Population effectiveness in women is now being demonstrated in countries with high vaccine coverage with significant reductions in high-grade cervical intra-epithelial neoplasia (a surrogate for cervical cancer), genital warts and vaccine HPV type genoprevalence. Herd effects in young heterosexual men and older women are evident. Cancers caused by HBV and HPV should, in theory, be amenable to immunotherapies and various therapeutic vaccines for HPV in particular are in development and/or in clinical trial.This article is part of the themed issue 'Human oncogenic viruses'.

Vulvar Intraepithelial Neoplasia (VIN) and Condylomata

Human papillomavirus (HPV) infection of the lower genital tract is common and its effects are variable. The majority of infections are transient and the related pathology is self-resolving. Condyloma accuminatum is caused predominantly by HPV 6, 11 and can be managed with medical or surgical therapy. Vulvar intraepithelial neoplasia is a treatable precursor to vulvar cancer with 2 main forms: one related to HPV and the other to chronic vulvar inflammatory conditions. It may be treated medically, surgically, or potentially via the use of therapeutic HPV vaccines. Preventive utilization of a quadrivalent HPV vaccine has the potential to decrease HPV-related lower genital disease burden substantially.

Vaccination against Oncoproteins of HPV16 for Noninvasive Vulvar/Vaginal Lesions: Lesion Clearance Is Related to the Strength of the T-Cell Response

PURPOSE

Therapeutic vaccination with human papillomavirus type 16 (HPV16) E6 and E7 synthetic long peptides (SLP) is effective against HPV16-induced high-grade vulvar and vaginal intraepithelial neoplasia (VIN/VaIN). However, clinical nonresponders displayed weak CD8(+) T-cell reactivity. Here, we studied if imiquimod applied at the vaccine site could improve CD8(+) T-cell reactivity, clinical efficacy, and safety of HPV16-SLP (ISA101).

EXPERIMENTAL DESIGN

A multicenter open-label, randomized controlled trial was conducted in patients with HPV16(+) high-grade VIN/VaIN. Patients received ISA101 vaccination with or without application of 5% imiquimod at the vaccine site. The primary objective was the induction of a directly ex vivo detectable HPV16-specific CD8(+) T-cell response. The secondary objectives were clinical responses (lesion size, histology, and virology) and their relation with the strength of vaccination-induced immune responses.

RESULTS

Forty-three patients were assigned to either ISA101 with imiquimod (n = 21) or ISA101 only (n = 22). Imiquimod did not improve the outcomes of vaccination. However, vaccine-induced clinical responses were observed in 18 of 34 (53%; 95% CI, 35.1-70.2) patients at 3 months and in 15 of 29 (52%; 95% CI, 32.5-70.6) patients, 8 of whom displayed a complete histologic response, at 12 months after the last vaccination. All patients displayed vaccine-induced T-cell responses, which were significantly stronger in patients with complete responses. Importantly, viral clearance occurred in all but one of the patients with complete histologic clearance.

CONCLUSIONS

This new study confirms that clinical efficacy of ISA101 vaccination is related to the strength of vaccine-induced HPV16-specific T-cell immunity and is an effective therapy for HPV16-induced high-grade VIN/VaIN. Clin Cancer Res; 22(10); 2342-50. ©2016 AACRSee related commentary by Karaki et al., p. 2317.

Medical and surgical interventions for the treatment of usual-type vulval intraepithelial neoplasia

BACKGROUND

Usual-type vulval intraepithelial neoplasia (uVIN) is a pre-cancerous condition of the vulval skin. Also known as high-grade VIN, VIN 2/3 or high-grade vulval squamous intraepithelial lesion (HSIL), uVIN is associated with high-risk subtype human papilloma virus (HPV) infection. The condition causes distressing vulval symptoms in the majority of affected women and may progress to vulval cancer, therefore is usually actively managed. There is no consensus on the optimal management of uVIN. High morbidity and recurrence rates associated with surgical treatments make less invasive treatments highly desirable.

OBJECTIVES

To determine which interventions are the most effective, safe and tolerable for treating women with uVIN.

SEARCH METHODS

We searched the Cochrane Gynaecological Cancer Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), Issue 8 2015, MEDLINE and EMBASE (up to 1 September 2015). We also searched registers of clinical trials, abstracts of scientific meetings, reference lists of included studies and contacted experts in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that assessed medical and surgical interventions in women with uVIN. If no RCTs were available, we included non-randomised studies (NRSs) with concurrent comparison groups that controlled for baseline case mix in multivariate analysis.

DATA COLLECTION AND ANALYSIS

We used Cochrane methodology with two review authors independently extracting data and assessing risk of bias. Where possible, we synthesised data in meta-analyses using random-effects methods. Network meta-analysis was not possible due to insufficient data.

MAIN RESULTS

We included six RCTs involving 327 women and five NRSs involving 648 women. The condition was variously named by investigators as uVIN, VIN2/3 or high-grade VIN. Five RCTs evaluated medical treatments (imiquimod, cidofovir, indole-3 carbinol), and six studies (one RCT and five NRSs) evaluated surgical treatments or photodynamic therapy. We judged two RCTs and four NRSs to be at a high or unclear risk of bias; we considered the others at relatively low risk of bias. Types of outcome measures reported in NRSs varied and we were unable to pool NRS data. Medical interventions: Topical imiquimod was more effective than placebo in achieving a response (complete or partial) to treatment at five to six months post-randomisation (three RCTs, 104 women; risk ratio (RR) 11.95, 95% confidence interval (CI) 3.21 to 44.51; high-quality evidence). At five to six months, a complete response occurred in 36/62 (58%) and 0/42 (0%) women in the imiquimod and placebo groups, respectively (RR 14.40, 95% CI 2.97 to 69.80). Moderate-quality evidence suggested that the complete response was sustained at one year (one RCT, nine complete responses out of 52 women (38%)) and beyond, particularly in women with smaller VIN lesions. Histologically confirmed complete response rates with imiquimod versus cidofovir at six months were 45% (41/91) and 46% (41/89), respectively (one RCT, 180 women; RR 1.00, 95% CI 0.73 to 1.37; moderate-quality evidence). Twelve-month data from this trial are awaited; however, interim findings suggested that complete responses were sustained at 12 months. Only one trial reported vulval cancer at one year (1/24 and 2/23 in imiquimod and placebo groups, respectively). Adverse events were more common with imiquimod than placebo and dose reductions occurred more frequently in the imiquimod group than in the placebo group (two RCTs, 83 women; RR 7.77, 95% CI 1.61 to 37.36; high-quality evidence). Headache, fatigue and discontinuation were slightly more common with imiquimod than cidofovir (moderate-quality evidence). Quality of life scores reported in one trial (52 women) were not significantly different for imiquimod and placebo. The evidence of effectiveness of topical treatments in immunosuppressed women was scant. There was insufficient evidence on other medical interventions. Surgical and other interventions: Low-quality evidence from the best included NRS indicated, when data were adjusted for confounders, that there was little difference in the risk of VIN recurrence between surgical excision and laser vaporisation. Recurrence occurred in 51% (37/70) of women overall, at a median of 14 months, and was more common in multifocal than unifocal lesions (66% versus 34%). Vulval cancer occurred in 11 women (15.1%) overall at a median of 71.5 months (9 to 259 months). The risk of vulval cancer did not differ significantly between excision and laser vaporisation in any of the NRSs; however, events were too few for robust findings. Alternative surgical procedures that might be as effective include Cavitron ultrasonic surgical aspiration (CUSA) and loop electrosurgical excision (LEEP) procedures, based on low- to very low-quality evidence, respectively. Very low-quality evidence also suggested that photodynamic therapy may be a useful treatment option.We found one ongoing RCT of medical treatment (imiquimod) compared with surgical treatment.

AUTHORS' CONCLUSIONS

Topical treatment (imiquimod or cidofovir) may effectively treat about half of uVIN cases after a 16-week course of treatment, but the evidence on whether this effect is sustained is limited. Factors predicting response to treatment are not clear, but small lesions may be more likely to respond. The relative risk of progression to vulval cancer is uncertain. However, imiquimod and cidofovir appear to be relatively well tolerated and may be favoured by some women over primary surgical treatment.There is currently no evidence on how medical treatment compares with surgical treatment. Women who undergo surgical treatment for uVIN have about a 50% chance of the condition recurring one year later, irrespective of whether treatment is by surgical excision or laser vaporisation. Multifocal uVIN lesions are at a higher risk of recurrence and progression, and pose greater therapeutic dilemmas than unifocal lesions. If occult cancer is suspected despite a biopsy diagnosis of uVIN, surgical excision remains the treatment of choice. If occult cancer is not a concern, treatment needs to be individualised to take into account the site and extent of disease, and a woman's preferences. Combined modalities may hold the key to optimal treatment of this complex disease.

Imiquimod in cervical, vaginal and vulvar intraepithelial neoplasia: a review

Human papillomavirus (HPV) infection is in the vast majority of patients accountable for the development of vulvar, cervical and vaginal intraepithelial neoplasia (VIN, CIN, VAIN); precursors of vulvar, cervical and vaginal cancers. The currently preferred treatment modality for high grade VIN, CIN and VAIN is surgical excision. Nevertheless surgical treatment is associated with adverse pregnancy outcomes and recurrence is not uncommon. The aim of this review is to present evidence on the efficacy, safety and tolerability of imiquimod (an immune response modifier) in HPV-related VIN, CIN and VAIN. A search for papers on the use of imiquimod in VIN, CIN and VAIN was performed in the MEDLINE, EMBASE and Cochrane library databases. Data was extracted and reviewed. Twenty-one articles met the inclusion criteria and were analyzed; 16 on VIN, 3 on CIN and 2 on VAIN. Complete response rates in VIN ranged from 5 to 88%. Although minor adverse effects were frequently reported, treatment with imiquimod was well tolerated in most patients. Studies on imiquimod treatment of CIN and VAIN are limited and lack uniformly defined endpoints. The available evidence however, shows encouraging effect. Complete response rates for CIN 2-3 and VAIN 1-3 ranged from 67 to 75% and 57 to 86% respectively. More randomized controlled trials on the use of imiquimod in CIN, VAIN and VIN with extended follow-up are necessary to determine the attributive therapeutic value in these patients.

Medical interventions for high-grade vulval intraepithelial neoplasia

BACKGROUND

This is an updated version of a review first published in theCochrane Database of Systematic Reviews, Issue 4, in 2011. Vulval intraepithelial neoplasia (VIN) is a pre-cancerous condition of the vulval skin and its incidence is increasing in women under 50 years. High-grade VIN (also called usual-type VIN (uVIN) or VIN 2/3 or high-grade vulval intraepithelial lesion) is associated with human papilloma virus (HPV) infection and may progress to vulval cancer, therefore is usually actively managed. There is no consensus on the optimal management of high-grade VIN; and the high morbidity and relapse rates associated with surgical interventions make less invasive interventions highly desirable.

OBJECTIVES

To evaluate the effectiveness and safety of medical (non-surgical) interventions for high-grade VIN.

SEARCH METHODS

We searched the Cochrane Gynaecological Cancer Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2015, Issue 3), MEDLINE and EMBASE (up to 30 March 2015). We also searched registers of clinical trials, abstracts of scientific meetings, reference lists of included studies and contacted experts in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that assessed non-surgical interventions in women diagnosed with high-grade VIN.

DATA COLLECTION AND ANALYSIS

We used Cochrane methodology with two review authors independently abstracting data and assessing risk of bias. Where possible, we synthesised data in meta-analyses using random effects methods.

MAIN RESULTS

Five trials involving 297 women with high-grade VIN (defined by trial investigators as VIN 2/3 or VIN 3 or 'high-grade' lesions) met our inclusion criteria: three trials assessed the effectiveness of topical imiquimod versus placebo; one assessed topical cidofovir versus topical imiquimod; and one assessed low- versus high-dose indole-3-carbinol in similar types of participants. Three trials were at a moderate to low risk of bias, two were at a potentially high risk of bias.Meta-analysis of the three trials comparing topical imiquimod 5% cream to placebo found that women in the active treatment group were more likely to show an overall response (complete and partial response) to treatment at five to six months compared with the placebo group (Risk Ratio (RR) 11.95, 95% confidence interval (CI) 3.21 to 44.51; participants = 104; studies = 3; I(2) = 0%; high-quality evidence). A complete response at five to six months occurred in 36/62 (58%) and 0/42 (0%) participants in the active and placebo groups, respectively (RR 14.40, 95% CI 2.97 to 69.80; participants = 104; studies = 3; I(2) = 0%). A single trial reported 12-month follow-up, which revealed a sustained effect in overall response in favour of the active treatment arm at 12 months (RR 9.10, 95% CI 2.38 to 34.77; moderate-quality evidence), with 9/24 (38%) and 0/23 (0%) complete responses recorded in the active and placebo groups respectively. Progression to vulval cancer was also documented in this trial (one versus two participants in the active and placebo groups, respectively) and we assessed this evidence as low-quality. Only one trial reported adverse events, including erythema, erosion, pain and pruritis at the site of the lesion, which were more common in the imiquimod group. Dose reductions occurred more frequently in the active treatment group compared with the placebo group (19/47 versus 1/36 participants; RR 7.77, 95% CI 1.61 to 37.36; participants = 83; studies = 2; I(2) = 0%; high-quality evidence). Only one trial reported quality of life (QoL) and there were no significant differences between the imiquimod and placebo groups.For the imiquimod versus cidofovir trial, 180 women contributed data. The overall response at six months was similar for the imiquimod and cidofovir treatment groups with 52/91 (57%) versus 55/89 (62%) participants responding, respectively (RR 0.92, 95% CI 0.73 to 1.18). A complete response occurred in 41 women in each group (45% and 46%, respectively; RR 1.00, 95% CI 0.73 to 1.37). Although not statistically different, total adverse events were slightly more common in the imiquimod group of this trial with slightly more discontinuations occurring in this group. Longer term response data from this trial are expected.The small trial comparing two doses of indole-3-carbinol contributed limited data. We identified five ongoing randomised trials of various interventions for VIN.

AUTHORS' CONCLUSIONS

Topical imiquimod appears to be a safe and effective treatment for high-grade VIN (uVIN), even though local side-effects may necessitate dose reductions. However, longer term follow-up data are needed to corroborate the limited evidence that response to treatment is sustained, and to assess any effect on progression to vulval cancer. Available evidence suggests that topical cidofovir may be a good alternative to imiquimod; however, more evidence is needed, particularly regarding the relative effectiveness on longer term response and progression. We await the longer-term response data and the results of the five ongoing trials.

VIN usual type-from the past to the future

Usual vulvar intraepithelial neoplasia (uVIN) is the most common VIN type, generally related to a human papillomavirus (HPV) infection, predominantly type 16. The incidence of uVIN has been increasing over the last decades, and a bimodal peak is observed at the age of 40–44 and over 55 years.

Almost 40% of patients with uVIN have a past, concomitant or future HPV-associated lesion of the lower genital tract. HPV-related malignancies are associated with a persistent HPV infection. The host immune response is of crucial importance in determining clearance or persistence of both HPV infections and HPV-related VIN. About 60% of the patients present with symptoms. Clinical features of uVIN vary in site, number, size, shape, colour, and thickness of lesions. Multicentric disease is often present.

Most uVIN lesions are positive at immunohistochemistry to p16^ink4a and p14^arf, but negative to p53.

Irrespective of surgical treatment used, uVIN recurrence rates are high. Positive margins do not predict the development of invasive disease and the need to re-excide the tissue around the scare remains to be demonstrated. Therefore, considering the low progression rate of uVIN and psycosexual sequelae, treatments should be as conservative as possible.

Medical treatments available are mainly based on immunotherapy to induce normalisation of immune cell count in uVIN. None are approved by the food and drug administration (FDA) for the treatment of uVIN. If medical treatment is performed, adequate biopsies are required to reduce the risk of unrecognised invasive disease. Some studies suggest that failure to respond to immunotherapy might be related to a local immunosuppressive microenvironment, but knowledge of the uVIN microenvironment is limited. Moreover, our knowledge of the potential mechanisms involved in the escape of HPV-induced lesions from the immune system has many gaps.

HPV vaccines have been demonstrated to be effective in preventing uVIN, with 94.9% efficacy in the HPV-naive population, while studies on therapeutic vaccines are limited. The low incidence of VIN requires large multicentre studies to determine the best way to manage affected patients and to investigate the immunological characteristics of the ‘vulvar microenviroment’ which leads to the persistence of HPV.

Sequential cisplatin therapy and vaccination with HPV16 E6E7L2 fusion protein in saponin adjuvant GPI-0100 for the treatment of a model HPV16+ cancer

Clinical studies suggest that responses to HPV16 E6E7L2 fusion protein (TA-CIN) vaccination alone are modest, and GPI-0100 is a well-tolerated, potent adjuvant. Here we sought to optimize both the immunogenicity of TA-CIN via formulation with GPI-0100 and treatment of HPV16+ cancer by vaccination after cisplatin chemotherapy. HPV16 neutralizing serum antibody titers, CD4+ T cell proliferative and E6/E7-specific CD8+ T cell responses were significantly enhanced when mice were vaccinated subcutaneously (s.c.) or intramuscularly (i.m.) with TA-CIN formulated with GPI-0100. Vaccination was tested for therapy of mice bearing syngeneic HPV16 E6/E7+ tumors (TC-1) either in the lung or subcutaneously. Mice treated with TA-CIN/GPI-0100 vaccination exhibited robust E7-specific CD8+ T cell responses, which were associated with reduced tumor burden in the lung, whereas mice receiving either component alone were similar to controls. Since vaccination alone was not sufficient for cure, mice bearing s.c. TC-1 tumor were first treated with two doses of cisplatin and then vaccinated. Vaccination with TA-CIN/GPI-0100 i.m. substantially retarded tumor growth and extended survival after cisplatin therapy. Injection of TA-CIN alone, but not GPI-0100, into the tumor (i.t.) was similarly efficacious after cisplatin therapy, but the mice eventually succumbed. However, tumor regression and extended remission was observed in 80% of the mice treated with cisplatin and then intra-tumoral TA-CIN/GPI-0100 vaccination. These mice also exhibited robust E7-specific CD8+ T cell and HPV16 neutralizing antibody responses. Thus formulation of TA-CIN with GPI-0100 and intra-tumoral delivery after cisplatin treatment elicits potent therapeutic responses in a murine model of HPV16+ cancer.