Abstract
We have previously demonstrated proof-of-principle of VGX-3100, an immunotherapy which targets HPV16/18 E6 and E7, in a Phase IIb study in women with premalignant cervical lesions caused by ...HPV16 or HPV18. After completion of the treatment regimen, cervical lesions underwent complete regression (CR) concomitant with elimination of underlying HPV16/18 infection in 40.0% of VGX-3100-treated patients and in only 14.3% of patients receiving placebo (p=0.002). Here we detail characteristics present that either correlated with or predicted therapeutic benefit with VGX-3100. Combining HPV typing and Pap smear data collected following the third dose (Week 14) was predictive for both CR and the elimination of HPV16/18 at the efficacy assessment twenty two weeks later (predictive value 94%, sensitivity 96%). Patients who had a significant elevation of peripheral blood CD137+ Perforin+ CD8+ T cells specific for the HPV type causing disease (p=0.001) were more likely to have lesion regression and HPV elimination than women without a detectable peripheral blood response. In comparisons of the intensity of cervical mucosal CD103+ and Perforin+ cell infiltrates pre- and post-vaccination, significant increases were observed in patients displaying exhibiting CR with elimination of HPV infection (p=0.027 and p=0.043, respectively). In sum, we found that quantitative measures associated with an effector response to VGX-3100 antigens were associated with subsequent lesion regression. These analyses indicate that certain immunologic responses are associated with successful resolution of HPV 16/18-induced pre-malignancy, with particular emphasis on the upregulation of Perforin in the immunotherapy induced immune response.
Immunotherapy that significantly impacts the clinical status of advanced cervical intraepithelial neoplasia (CIN) has the potential to provide physicians an important alternative to surgery to treat ...CIN 2/3 disease. Our previous two Phase I studies of VGX3100, a highly optimised DNA immunotherapy for HPV16/18, drove seroconversion to HPV antigens in 100% of patients while 78% of patients mounted an Interferon Gamma (IFNg) ELISpot response. Flow analysis revealed IFNg production from both CD4+ and CD8+ T cells, as well as the induction of patient CD8s with antigen specific CTL activity. This randomized, placebo-controlled, double-blind Phase II study assessed the safety and efficacy of VGX3100 in 167 women with biopsy-proven CIN 2/3 with concurrent HPV16 or 18 infection. The study evaluated cervical tissue changes after three 6 mg intramuscular doses of VGX-3100 with Inovio’s CELLECTRA® 2000 electroporation device at weeks 0, 4, 12. Cervical tissue was examined before starting blinded treatment and 9 months later. The study met its primary efficacy endpoint; Significantly higher percentage of VGX3100 treated patients versus placebo showed regression of CIN 2/3 to CIN 1 or no disease ( p = 0.017). In addition, VGX3100 recipients demonstrated significantly stronger post-vaccination IFNg ELISpot responses and cleared HPV infection concurrent with regression of CIN lesions. The efficacy data with VGX3100 support the exciting possibility of treating HPV-associated cancers.
We introduce two test procedures for comparing two survival distributions on the basis of randomly right-censored data consisting of both paired and unpaired observations. Our procedures are based on ...generalizations of a pooled rank test statistic previously proposed for uncensored data. One generalization adapts the Prentice-Wilcoxon score, while the other adapts the Akritas score. The use of these particular scoring systems in pooled rank tests with randomly right-censored paired data has been advocated by several researchers. Our test procedures utilize the permutation distributions of the test statistics based on a novel manner of permuting the scores. Permutation versions of tests for right-censored paired data and for two independent right-censored samples that use the proposed scoring systems are obtained as special cases of our test procedures. Simulation results show that our test procedures have high power for detecting scale and location shifts in exponential and log-logistic distributions for the survival times. We also demonstrate the advantages of our test procedures in terms of utilizing randomly occurring unpaired observations that are discarded in test procedures for paired data. The tests are applied to skin graft data previously reported elsewhere.
Abstract
Objectives
Assessment of the safety and efficacy and immunogenicity of VGX-3100 in women with biopsy-proven CIN2/3 with concurrent HPV16 and/or HPV18 infection.
Methods
The randomized, ...placebo-controlled, double-blind study, which was stratified by age and severity of CIN, evaluated cervical tissue changes after three 6 mg intramuscular doses of VGX-3100 followed by electroporation with Inovio’s CELLECTRA2000 device at weeks 0, 4, and 12.
Results
Among 167 vaccinated women, the study met its primary efficacy endpoint; the percentage of patients who had regression of CIN2/3 to CIN1 or no disease at 6 months post third dose was significantly higher in the VGX-3100 group compared to placebo (p=0.034). In addition, the trial demonstrated the ability of VGX-3100 to clear HPV infection concurrent with regression of CIN2/3 (p=0.003). Post-hoc immune analysis also revealed significantly elevated immune responses in treated patients who had CIN2/3 regression concurrent with HPV clearance when compared to those who did not. This included the presence of CD8+ T cells in the blood exhibiting CD137 expression concurrent with perforin (p=0.032) as well as perforin in addition to granzyme A (p=0.036) as well as an influx of CD8+ T cells into cervical tissue (p=0.008).
Conclusion
The successful phase 2b results represent a significant milestone in the development of active immunotherapies to treat HPV-related dysplasia and cancer. The data generated from the trial reveal statistically significant correlations between antigen specific T cell activity and clinical benefits afforded by VGX-3100. Thus VGX-3100 has the potential to provide an important alternative or adjunct to surgery in treating CIN 2/3 based on HPV specific T cell activity.
Background: Recurrent respiratory papillomatosis (RRP) is a rare disorder characterized by the generation of papillomas of the aerodigestive tract, usually associated with human papilloma virus (HPV) ...subtypes 6, 11. INO-3106 is a DNA plasmid-based immunotherapy targeting E6 and E7 proteins of HPV6, in order to create a robust immune T cell response. Methods: Testing of INO-3016 in animal models confirmed immunogenicity of the DNA-based therapy. A single-site open-label Phase 1 study was initiated for patients with HPV6-positive RRP. Patients were dosed with INO-3106 with or without INO-9012, a DNA plasmid immunotherapy that encodes IL-12, delivered intramuscularly (IM) in combination with electroporation (EP) with the CELLECTRA® device. Patients received an escalating dose of INO-3106, 3 mg once and then 6 mg for three additional doses, each dose three weeks apart, with the third and fourth doses co-administered with INO-9012. The primary objective of the study was to evaluate the safety and tolerability of INO-3106 with and without INO-9012. The secondary objective was to determine cellular immune responses to INO-3106 with and without INO-9012. Exploratory objectives included preliminary clinical efficacy to the therapy. Results: Three patients were enrolled in this study, of which two had RRP. Study therapy was well-tolerated, with no related serious adverse events and all related adverse events (AEs) were low-grade. Injection site pain was the most common related AE reported. Immunogenicity was evidenced by multiple immune assays showing engagement and expansion of an HPV6-specific cellular response, including cytotoxic T cells. Preliminary efficacy was demonstrated in patients with RRP in the form of reduction in need for surgical intervention for papilloma growth. Prior to intervention, both patients required surgical intervention approximately every 180 days. One patient demonstrated a greater than three-fold increase in surgery avoidance (584 days) and the other patient remains completely surgery-free as of the last contact at 915 days, a greater than 5-fold increase in surgery interval. Conclusion: INO-3106 with and without INO-9012 was well tolerated, immunogenic and demonstrated preliminary efficacy in patients with HPV6-associated RRP aerodigestive lesions. Further clinical study is indicated.
Abstract
The most recent Ebola outbreak in West Africa resulted in over 28,000 suspected cases of infection and over 11,000 deaths. As no specific immune correlate has been associated with protection ...against Ebola to date, the development of a vaccine that generates robust humoral and cellular immune responses may be the best approach to achieve full protection. INO-4201 is a plasmid-based prophylactic vaccine targeting Zaire Ebola glycoprotein (GP), designed to prevent Ebola infection. INO-4201 encodes a consensus antigen that encompasses genetic variability from previous outbreak strains to broaden immune coverage for divergent Ebola virus variants. Intradermal (ID) administration of a 2 or 3-dose regimen of INO-4201 followed by in vivo electroporation with the CELLECTRA® device was well tolerated in 140 healthy volunteers with no related Grade 3 or Grade 4 SAEs reported. INO-4201 induced robust Ebola GP-specific antibody and T cell responses in the healthy volunteers. The majority of patients seroconverted, as gauged by binding ELISA after only 2 doses of INO-4201. EBOV GP specific T cell response were assessed by Interferon gamma (IFNγ) ELISpot revealing a mean peak response magnitude of 295 SFU per 106 PBMCs. Intracellular cytokine staining indicated that immunization with INO-4201 drove statistically significant increases in the production of IFNγ or Tumor Necrosis Factor alpha in both the CD8+ T cell compartment (p=0.001) and CD4+ T cell compartment (p=0.004). ID administration of INO-4201 using the CELLECTRA® device was well tolerated and immunogenic as assessed by both humoral and cellular EBOV GP-specific immunoassays supporting INO-4201 as a strong candidate for further clinical development of a prophylactic Ebola vaccine.
Dallas and Rao (Biometrics 56 (2000) 154) proposed a class of permutation tests for testing the equality of two survival distributions based on randomly right censored survival time data consisting ...of both paired and unpaired observations. Data sets of this type can occur frequently in medical settings. Two members of this class were advocated for use due to their generally high power for detecting scale and location shifts in the exponential and log-logistic distributions for the survival times, and improved power over paired data test procedures that disregard unpaired observations. Because the computations for the tests become quite laborious as the sample sizes increase, computing routines are required for practical implementation of these tests. This paper provides computing routines to execute the tests.
Abstract
The advent of an immunotherapy that imparts a significant impact on the clinical status of advanced cervical intraepithelial neoplasia (CIN) has the potential to provide physicians an ...important alternative to surgery to treat CIN 2/3 disease. Our previous two phase I studies of VGX-3100, a highly optimized DNA immunotherapy for HPV16/18 delivered using electroporation, drove seroconversion as gauged by ELISA to at least one HPV antigen (E6 or E7) in 100% of patients while 78% of patients mounted a Interferon Gamma (IFNg) ELISpot response. Moreover, all patients showed the presence of CD8 T cells exhibiting full HPV-specific cytolytic functionality, a readout thought to be informative of the ability of VGX-3100 to induce an immune response that may be important for the direct elimination of HPV infected cells.
The phase II study, designated HPV-003, assessed the safety and efficacy of VGX-3100 in 167 women with biopsy-proven CIN 2 or CIN 3 with concurrent HPV16/18 infection. The randomized, placebo-controlled, double-blind study, was stratified by age and severity of CIN and evaluated cervical tissue changes after three 6 mg intramuscular doses of VGX-3100 followed by electroporation (EP) with Inovio's CELLECTRA® 2000 device at weeks 0, 4, and 12. Cervical tissue was examined before starting blinded treatment and 9 months later. The study met its primary efficacy endpoint; the percentage of patients who had regression of CIN 2 or CIN 3 to CIN 1 or no disease at 6 months post third dose was significantly higher in the VGX-3100 group compared to the placebo group (p = 0.017). In addition, the trial demonstrated the ability of VGX-3100 clear HPV infection concurrent with regression of CIN lesions. The study also explored cellular immune responses to VGX-3100 in blood samples taken prior to the first vaccine dose and periodically thereafter. IFN-γ ELISpot results revealed higher responses in the VGX-3100 treated group than in the placebo group, suggesting that VGX-3100 was able to robustly engage the cellular arm of the patients’ immune system.
Altogether, the successful phase 2 results represent a significant milestone in the development of active immunotherapies to treat cancer and infectious diseases and have the potential to provide physicians an important alternative to surgery to treat CIN 2/3 disease. They illustrate the highly promising potential of therapeutic immunization with DNA using electroporation for the treatment of HPV-related precancerous cervical disease in women and present the possibility of treating other HPV-associated cancers.
Citation Format: Matthew Morrow, Cornelia Trimble, Xuefei Shen, Michael Dallas, David Weiner, Jean Boyer, Jian Yan, Kimberly Kraynyak, Albert Sylvester, Mary Giffear, Kathleen Marcozzi-Pierce, Divya Shah, Kate Broderick, Amir Khan, Jessica Lee, Laurent Humeau, Niranjan Sardesai, Mark Bagarazzi. HPV specific immunotherapy for cervical intraepithelial neoplasia using VGX-3100 induces regression of cervical lesions and potent T-cell responses: Results from a randomized, double-blind, placebo-controlled phase II study. abstract. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT131. doi:10.1158/1538-7445.AM2015-CT131
Abstract
Here we report the results of a Phase II study assessing the safety and efficacy of VGX-3100 in 167 women with biopsy-proven CIN 2/3 with concurrent HPV16/18 infection. The randomized, ...placebo-controlled, double-blind study evaluated cervical tissue changes after three 6 mg intramuscular doses of VGX-3100 followed by electroporation (EP) with Inovio’s CELLECTRA®2000 device at weeks 0, 4, and 12. Cervical tissue was examined before treatment and 9 months later. The study met its primary efficacy endpoint; the percentage of patients who had regression of CIN 2/3 to CIN 1 or no disease at 6 months post third dose was significantly higher in the VGX-3100 group compared to the placebo group (p=0.017). In addition, the trial demonstrated the ability of VGX-3100 clear HPV infection concurrent with regression of CIN lesions. The study also explored humoral and cellular immune responses to VGX-3100 in blood samples taken periodically during the trial. ELISA as well as IFN-g ELISpot results revealed significantly higher responses in the VGX-3100 treated group than in the placebo group, suggesting that VGX-3100 was able to robustly engage the patients’ immune system. Altogether, the successful phase 2 results represent a significant milestone in the development of active immunotherapies not only to robustly engage the immune system but also to treat cancer and infectious diseases and have the potential to provide physicians an important alternative to surgery to treat CIN 2/3 disease.
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