VTP-200 Elicits Immunogenic Responses, Tolerability in HPV+ Cervical Lesions

VTP-200 generated immunogenic responses and tolerability in patients with human papillomavirus (HPV)–positive cervical lesions, according to topline interim data from the phase 1b/2 HPV001 trial (NCT04607850).¹

Among women who reached the 6-month timepoint in the placebo-controlled study (n = 58), immunogenicity data demonstrated high responses, defined as an average more than 1000 spot-forming units per million peripheral blood mononuclear cells in an ELISPOT assay, especially to the E1, E2 and E6 antigens.

Additionally, no grade 3 unsolicited treatment-related adverse effects (TRAEs) and no serious TRAEs were reported.

Although results were unblinded by group, the results will not be fully reported until the trial is complete and the data are fully unblinded. Interim data will be presented at the International Papillomavirus Conference, which is being held from April 17-21 in Washington, D.C.

“These interim data are a promising step in the right direction, and we look forward to seeing the final data in early 2024. Currently people with persistent HPV infections have no treatment options until they develop high grade lesions. Being told to return for a repeat cervical screening every 6 to 12 months without a treatment option can be frustrating and anxiety-provoking,” Bill Enright, chief executive officer of Vaccitech, stated in a news release. “VTP-200 is intended to treat HPV infections, potentially before the virus causes these high-grade lesions.”

VTP-200 is an investigational heterologous prime boost immunotherapy consisting of an initial dose using the ChAdOx vector and a second dose using modified vaccinia virus Ankara (MVA), both encoding the same HPV antigens, to elicit an immune response to HPV. VTP-200 is being developed as a potential noninvasive treatment for persistent high-risk HPV infections and associated pre-cancerous lesions.

HPV001 is a randomized, placebo-controlled phase 1b/2 multicenter trial evaluating the safety, efficacy, and immunogenicity of VTP-200. The study has been fully enrolled.

The trial included an open-label, non-randomized, dose-escalation lead-in phase that enrolled 9 women, which was followed by a blinded, randomized main phase of approximately 96 patients with high-risk HPV.

The trial enrolled women between the ages of 25 and 55 with a persistent high-risk HPV infection and a low-grade cervical lesion (CIN1 or HPV-related change only) confirmed by histology and/or cytology report within the 1 year prior to screening.²

In the blinded portion of the trial, patients were randomly assigned to 1 of 5 treatment groups evaluating different doses of ChAdOx1-HPV and MVA-HPV, or a sixth group that received placebo.

Safety is serving as the primary end point of the trial. Secondary end points include determining the dose of ChAdOx1-HPV plus MVA-HPV for future trials, the effect of ChAdOx1-HPV plus MVA-HPV on clearance of HPV, and the effect of ChAdOx1-HPV plus MVA-HPV on cervical intraepithelial neoplasia. Other end points consist of assessing cellular immune response.

References

1. Vaccitech’s VTP-200 ph 1b/2 study demonstrates favorable tolerability and immunogenicity profile at interim analysis in women with low-grade human papillomavirus (HPV)-related cervical lesions. News release. Vaccitech. March 20, 2023. Accessed March 20, 2023. https://investors.vaccitech.co.uk/news-and-events/
2. Prime-boost vaccine study in women with low-grade cervical HPV lesions. ClinicalTrials.gov. Updated January 10, 2023. Accessed March 20, 2023. https://clinicaltrials.gov/ct2/show/NCT04607850