ApolloBio, Inovio Pharmaceuticals' (Nasdaq: INO) Chinese partner, has announced that VGX-3100, a DNA immunotherapy targeting HPV16 and HPV18, met its primary efficacy endpoint in a pivotal Phase III trial for cervical high-grade squamous intraepithelial lesions (HSIL), providing the clinical basis for a regulatory submission in China where no approved pharmacological treatment for cervical dysplasia currently exists.
The Phase III study is a multicenter, randomized, double-blind, placebo-controlled trial conducted across 22 tertiary hospitals in China, led by Professor Lingying Wu of the Cancer Hospital, Chinese Academy of Medical Sciences. The primary endpoint was a composite response rate at Week 36, requiring both histopathologic regression to CIN1 or normal histology and clearance of HPV-16 and/or HPV-18 infection. ApolloBio reported the trial met this predefined endpoint, with no new significant safety signals observed and an overall favorable tolerability profile. Specific response rates were not disclosed in the topline announcement; full data are expected at upcoming international conferences and in peer-reviewed publications.
VGX-3100 works by delivering DNA plasmids encoding optimized HPV16 and HPV18 E6 and E7 oncoproteins, delivered via Inovio's proprietary CELLECTRA electroporation device, to stimulate antigen-specific CD8+ T cell responses against HPV-infected dysplastic cells. The cervical HSIL space has no approved pharmacological therapy in any major market; current standard of care relies entirely on excisional procedures such as LEEP and cold knife conization, which carry risks of cervical incompetence and preterm birth in women of reproductive age.
VGX-3100 has a long development history in the US, where Inovio previously reported mixed Phase III results in cervical HSIL. The company’s REVEAL 1 study, announced in 2021, did not meet its primary endpoint under the FDA-agreed analysis plan, and subsequent US development was deprioritized. The positive China Phase III outcome therefore represents a potential revival of the program through ApolloBio’s regional development strategy.