Evaluation of VGX-3100 and Electroporation Alone or in Combination With Imiquimod for the Treatment of HPV-16 and/or HPV-18 Related Vulvar HSIL (Also Referred as: VIN 2 or VIN 3)

A treatment responder for the primary endpoint was defined as a participant with no histologic evidence of vulvar HSIL (normal tissue or vulvar low grade squamous intraepithelial lesions (LSIL) [vulval intraepithelial neoplasia 1 (VIN1)] or condyloma) and no evidence of HPV-16 or HPV-18 (i.e., elimination of the specific genotypes [16, 18, or both]) in vulvar tissue at evaluation and who did not receive any non-study related treatment for vulvar HSIL. All lesions were evaluated for histologic evidence of vulvar HSIL or evidence of HPV-16/18 in vulvar tissue.

An adverse event (AE) was defined as any unfavorable and unintended change in the structure, function, or chemistry of the body, or worsening of a pre-existing condition, temporally associated with the use of a product whether or not considered related to the use of the product. A TEAE was defined per protocol as any AE with onset after the administration of study medication through the end of the study (i.e., study discharge).

An AE was defined as any unfavorable and unintended change in the structure, function, or chemistry of the body, or worsening of a pre-existing condition, temporally associated with the use of a product whether or not considered related to the use of the product.

Participants with no histologic evidence of vulvar HSIL (normal tissue or vulvar LSIL [VIN1] or condyloma) based on histology (i.e. biopsies or excisional treatment) were considered. All lesions were evaluated for histologic evidence of vulvar HSIL.

Participants with no evidence of HPV-16 and/or HPV-18 indicated the clearance of the specific HPV genotypes [16, 18, or both]. All lesions were evaluated for evidence of HPV-16/18 in vulvar tissue.

A treatment responder for the endpoint was defined as a participant with no histologic evidence of vulvar HSIL (normal tissue or LSIL [VIN1] or condyloma) based on histology (i.e. biopsies or excisional treatment) or no evidence of HPV-16 or HPV-18 (i.e., elimination of the specific genotypes [16, 18, or both]) in vulvar tissue at evaluation and who did not receive any non-study related treatment for vulvar HSIL. All lesions were evaluated for histologic evidence of vulvar HSIL or evidence of HPV-16/18 in vulvar tissue.

Histologic regression was defined as a participant with no histologic evidence of vulvar HSIL, no evidence of LSIL (VIN1), and no evidence of condyloma. Histologic regression of vulvar HSIL to normal tissue was assessed.

Non-progression of vulvar HSIL to vulvar cancer was evaluated from baseline to Week 48. Progression was defined as advancement to carcinoma by histology.

Lesion(s), defined as areas that stain acetowhite were assessed. Analysis of qualifying lesions was defined as the change in total surface area of only lesions with both baseline and Week 48 measurements. Percent change in the cumulative surface area of the acetowhite vulvar lesion(s) was determined by the quantitative analysis of standardized prebiopsy photographic imaging of qualifying lesion(s) at Week 48 compared to baseline.

Peripheral blood mononuclear cells (PBMCs) were isolated from whole blood samples. Assessment of cellular immune activity was performed by IFN-γ enzyme-linked immunosorbent spot-forming (ELISpot) assay.

A standardized binding enzyme-linked immunosorbent assay (ELISA) was performed to measure the anti-HPV-16/18 antibody response induced by VGX-3100.

Assessment of cellular immune activity was measured using the application of flow cytometry for the purpose of performing a Lytic Granule Loading Assay. The Lytic Granule Loading Assay examines the following external cellular markers: cluster of differentiation 3 (CD3), CD4, CD8 (T-cell identification), CD137, CD38, and CD69 (T-cell activation markers) as well as PD-1 (exhaustion/activation marker). Here, a change from baseline in CD8+/CD137+ PBMCs expressing Perforin+ was reported.