A new analysis of circulating tumor DNA (ctDNA) results from a clinical trial evaluating Versamune® HPV in locally advanced cervical cancer has revealed promising efficacy signals for the novel immunotherapy approach.
Significant ctDNA Clearance Demonstrates Treatment Response
The study enrolled 66 patients with locally advanced cervical cancer, with 49 receiving standard chemoradiotherapy (CRT) and 17 receiving CRT combined with Versamune® HPV. Researchers tracked HPV ctDNA levels through blood samples collected at baseline, weeks 1, 3, and 5 of treatment, and at 3-4 months post-treatment follow-up.
The results showed a marked difference between treatment groups. All HPV16-positive patients (5/5) who received the combination of CRT and Versamune® HPV achieved complete clearance of HPV16-positive ctDNA at the 3-4 month follow-up. In contrast, only 50% (3/6) of patients receiving standard CRT alone showed ctDNA clearance.
Strong Correlation with Survival Outcomes
The study demonstrated that HPV ctDNA clearance at 3-4 months strongly predicted better clinical outcomes. Patients who achieved ctDNA clearance showed significantly improved 2-year recurrence-free survival of 92.9% compared to 30% in those with detectable ctDNA (P = 0.0067). The predictive power of HPV ctDNA clearance was particularly robust, achieving a concordance index score of 0.83.
Impressive Long-term Survival Data
Long-term follow-up data further supported the therapeutic potential of Versamune® HPV. Among patients who received the full course of five doses combined with CRT, the 36-month overall survival rate reached 100%. Even in patients who received at least two doses of Versamune® HPV with CRT, the 36-month overall survival rate remained high at 84.4%.
Treatment Protocol and Monitoring
The trial protocol incorporated sophisticated monitoring techniques, including MRI scans at baseline and pre-brachytherapy to assess tumor shrinkage. With a median follow-up of 23 months, the study provided robust data on both short-term response and longer-term outcomes.
PDS Biotech, the company developing Versamune® HPV, is advancing its immunotherapy platform with plans to initiate a pivotal trial in HPV16-positive head and neck squamous cell cancers. The company is also exploring combination approaches, including pairing Versamune® HPV with checkpoint inhibitors and investigating a triple combination therapy that includes PDS01ADC, an IL-12 fused antibody drug conjugate.
