Novel IO Yields ‘Encouraging’ Immunogenicity in Cervical HPV-Related Lesions

The investigational immunotherapy agent VTP-200 produced an encouraging immunogenicity profile and was generally well tolerated among patients with low-grade cervical human papillomavirus (HPV) lesions, according to a press release on topline interim data from the phase 1b/2 HPV001 study (NCT04607850).

"These interim data are a promising step in the right direction and we look forward to seeing the final data in early 2024," according to the manufacturers of VTP-200 regarding the phase 1b/2 HPV001 study.

Following a review of data from the first 58 patients who reached the 6-month timepoint in the study, immunogenicity results highlighted high responses following treatment with VTP-200. This was defined as an average of higher than 1000 spot-forming units per million peripheral blood mononuclear cells in an enzyme-linked immunosorbent spot assay, especially in E1, E2, and E6 antigens. Additionally, VTP-200 produced no grade 3 treatment-related adverse effects (TRAEs) and no serious TRAES.

Although results were unblinded, to preserve the integrity of the data results are not set to read out until after the study is complete. Investigators will present interim data from the HPV001 study at the International Papillomavirus Conference in Washington, DC on April 17 to 21, 2023.

“These interim data are a promising step in the right direction and we look forward to seeing the final data in early 2024,” Bill Enright, chief executive officer of Vaccitech, said in the press release. “Currently people with persistent HPV infections have no treatment options until they develop high grade lesions…. VTP-200 is intended to treat HPV infections, potentially before the virus causes these high-grade lesions.”

The investigational heterologous prime boost immunotherapy VTP-200 includes an initial dose with the ChAdOx vector and a second dose with MVA. Both doses encode the same HPV antigens, eliciting an immune response to HPV. Investigators are developing VTP-200 as a potential non-invasive treatment for persistent high-risk HPV infections and pre-cancerous lesions.

Investigators of the fully enrolled, randomized, multi-center, placebo-controlled phase 1b/2 HPV001 trial assessed the efficacy, safety, and immunogenicity of VTP-200 in patients with low-grade cervical lesions related to HPV. The study included a lead-in dose escalation phase of 9 patients followed by a blinded, randomized phase of roughly 96 patients with high-risk HPV.

Patients in the experimental arms received varying doses of the ChAdOx1-HPV and MVA-HPV vaccines, and those in the comparator arm received a saline-based placebo vaccine.

The primary end point of the study was the incidence of AEs, serious AEs, and grade 3 or higher vaccine-related AEs. Secondary end points included the effect of the VTP-200 vaccine on the clearance of high-risk HPV infection and on cervical intraepithelial neoplasia as well as the vaccine’s generation of complex cellular immune responses.

Patients 25 to 55 years old with a persistent HPV infection and low-grade cervical lesions confirmed with a histology or cytology report within 1 year prior to screening were eligible for enrollment on the trial. Additional inclusion criteria included not being pregnant and being willing to abstain from sexual activity for 48 hours prior to swabbing procedures.

Patients with the presence of any significant acute or chronic, uncontrolled medical illness including blood dyscrasias or those with immunosuppression following underlying illness or treatment were not eligible for enrollment. Patients were also unsuitable for enrollment if they had positive diagnostic tests for human immunodeficiency virus, hepatitis B, or hepatitis C; evidence of high-grade cervical lesions by colposcopy 1 year prior to screening; or received any investigational treatment within 3 months prior to administration of VTP-200.

Reference

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 21, 2023. yhoo.it/3JvAZIR