A clinical trial indicates that a therapeutic vaccine aimed at human papillomavirus type 16 (HPV16) led to the regression of advanced precancerous cervical lesions. This finding comes from a phase II study presented in the journal Clinical Cancer Research, published by the American Association for Cancer Research.
A clinical trial indicates that a therapeutic vaccine aimed at human papillomavirus type 16 (HPV16) led to the regression of advanced precancerous cervical lesions. This finding comes from a phase II study presented in the journal Clinical Cancer Research, published by the American Association for Cancer Research.
Refika Yigit, MD, who is the principal investigator and an oncological gynecologist at University Medical Centre Groningen in the Netherlands, stated, “Almost all precancerous cervical lesions and cervical cancers arise from HPV infections, with HPV16 being responsible for most cases.”
For individuals with grade 3 cervical intraepithelial neoplasia (CIN3), the cells are already moving toward malignancy. If not treated, around one-third of these cases may develop into cervical cancer within 10 years, and about half within 30 years, Yigit noted.
“The primary goal of our trial was to see if our therapeutic vaccine — Vvax001 — could serve as a viable alternative to the standard loop excision treatment, which often has associated complications,” Yigit remarked.
The Vvax001 vaccine is a modified Semliki Forest virus that cannot replicate and generates the oncogenic E6 and E7 proteins, which are present only in cells infected with HPV16.
During the phase II trial, 18 patients with HPV16-positive CIN3 received three doses of Vvax001 spaced three weeks apart. They were then monitored regularly through colposcopy and had a final colposcopy-guided biopsy at 19 weeks after vaccination.
Nine out of the 18 patients showed regression — six had low-grade dysplasia, while three showed complete regression with no signs of dysplasia. Notably, lesion sizes were significantly reduced in all but one patient, with these reductions observable just a month after completing the vaccination. The nine patients whose conditions did not regress underwent loop excision surgery, but no residual disease was detected in four, indicating that the delay before surgery might have facilitated complete lesion eradication, the authors suggested.
“As far as we know, this response rate makes Vvax001 one of the most potent therapeutic vaccines for HPV16-related CIN3 lesions reported so far,” Yigit explained. “If these findings are validated in a larger study, it could mean that at least half of the CIN3 patients might avoid surgery along with its potential side effects and complications.”
In standard treatment, clearing HPV is related to a lower chance of recurrence, and Yigit’s team anticipates a similar outcome here. Among the 16 patients assessed, 10 cleared HPV16, including all nine with regressed disease. Two patients without regression also cleared HPV16, but their lesions contained other HPV strains.
After a median follow-up period of 20 months, none of the patients experienced recurrences.
The study’s limitations include a short follow-up duration, a small participant group, and the absence of a control group for spontaneous regression due to ethical issues.
This research received funding from the Dutch Cancer Society (KWF) and ViciniVax.
