A therapeutic vaccine targeting human papillomavirus type 16 (HPV16) promoted regression in high-grade precancerous cervical lesions, according to the results from a phase II clinical study published in Clinical Cancer Research, a journal of the American Association for Cancer Research.
The cells in patients with grade 3 cervical intraepithelial neoplasia (CIN3) are already headed toward cancer. According to Yigit, if treatment is not received, about one-third of these instances develop cervical cancer within ten years, and about half do so within thirty.
“Our trial’s primary goal was to determine whether our therapeutic vaccination, Vvax001-, might provide a viable substitute for the standard-of-care loop excision procedure, which is sometimes linked to problems,” Yigit continued.
The Semliki Forest virus used in the Vvax001 vaccine is altered to be incapable of replicating and to produce the carcinogenic E6 and E7 proteins, which are only expressed by HPV16-infected cells.
Following three doses of Vvax001 spaced three weeks apart, 18 patients with HPV16-positive CIN3 were routinely examined by colposcopy in the phase II trial. At 19 weeks after the vaccination, a final colposcopy-guided biopsy was performed.
Three of the 18 patients had full regressions with no dysplasia, and nine of them had regression-six to low-grade dysplasia. All except one of the patients experienced a considerable reduction in lesion size, which became apparent a month after the vaccine was completed. Loop excision surgery was performed on the nine patients whose disease did not regress; nonetheless, the investigators observed no residual disease in four of these patients, indicating that the extra time before surgery might have allowed for complete lesion elimination.
“As far as we are aware, this response rate places Vvax001 among the most potent therapeutic vaccines for HPV16-associated CIN3 lesions that have been documented thus far,” Yigit stated. According to our findings, “at least half of the patients with CIN3 might be able to omit surgery and prevent all its possible side effects and risks if proven in a bigger experiment.”
According to Yigit, her team anticipates that HPV clearance will result in a decreased risk of recurrence, just as it does in the standard-of-care environment. Of the 16 patients assessed, 10 had HPV16 cleared, including all nine whose illness had regressed. HPV16 was also eliminated in two individuals whose illness did not improve; however, additional HPV strains were present in their lesions.
There were no recurrences among the patients after a median follow-up of 20 months.
The study’s shortcomings include a small sample size, a short follow-up period, and the absence of a control group for spontaneous regression because to ethical concerns.
ViciniVax and the Dutch Cancer Society (KWF) provided support for this study. Yigit says he has no competing interests.
-NSH Digidesk
