A Phase II, Prospective, Randomized, Multicenter, Open-Label Study of GX-188E, an HPV DNA Vaccine, in Patients with Cervical Intraepithelial Neoplasia 3

Abstract

Purpose: To determine the efficacy of the therapeutic DNA vaccine GX-188E for inducing regression of cervical intraepithelial neoplasia (CIN) 3. Patients and Methods: We conducted a prospective, randomized, multicenter, open-label, phase II clinical trial of GX-188E in CIN3 patients positive for human papillomavirus (HPV) type 16/18. The primary endpoint was to determine the histopathologic regression to <= CIN1 at visit seven (V7; 20 weeks after the first GX-188E injection), and an extension study was pursued until visit 8 (V8; 36 weeks after the first GX-188E injection). HPV-sequencing analysis and an ex vivo IFN gamma ELISpot assay were performed using the collected cervical biopsy and blood samples from patients. Results: In total, 72 patients were enrolled and underwent randomization. Of them, 64 patients were included in per-protocol analysis (V7) and 52 in extension analysis (V8). Our data showed 52% (33/64) of patients at V7 and 67% (35/52) of patients at V8 presented histopathologic regression after receiving the GX-188E injection. We found that 73% (V7) and 77% (V8) of the patients with histologic regression showed HPV clearance. HPV clearance and histopathologic regression were significantly associated at V7 and at V8. Compared with the measurements at V1 (baseline), the patients at V8 with HPV clearance showed significantly higher fold changes in their IFN gamma ELISpot responses compared with those without HPV clearance. The HPV sequence analysis revealed that the HPV type 16 E6/E7 variants D25E, V83L, and N29S were inversely associated with histopathologic regression at V8. Conclusions: GX-188E is an effective therapeutic vaccine against a cohort containing only CIN3 patients.