Experimental treatment completely eliminates HPV in one-third of precursors of cervical cancer

A new potential immune treatment for the treatment of precancerous cervical cancer completely eliminated both the lesion and the underlying HPV infection in one-third of women enrolled in a clinical trial.

The vaccine, a therapeutic vaccine, injects a specific protein that triggers an immune system reaction to attack the high-risk HPV types responsible for almost all precursors of cervical cancer, called cervical intraepithelial neoplasia (CIN).

"Very few products are trying to cure women already infected with HPV," says Diane Harper, MD, M.P.H., MS, a professor of family medicine, obstetrics and gynecology at Michigan Medicine. "It's very exciting – it's the first time that this success rate is relatively easy to implement."

Precancerous cervical lesions are divided into three degrees of severity: CIN 1 lesions usually resolve on their own. CIN 2 lesions often go away on their own, but can also progress to CIN 3 lesions. CIN 3 is the most serious. This is a very slow growing disease however: less than half of the CIN 3 lesions will have become cancer in the next 30 years.

"But we have no way of determining which women with CIN 3 will progress to cancer and which ones will not, so we treat all women with CIN 2 or 3 as if they are at risk of developing cancer. "said Harper.

The study recruited 192 women diagnosed with CIN2 or CIN3, 129 randomized to receive the vaccine and 63 to receive a placebo. The women received three injections in the thigh, one per week for three weeks. Six months later, women were treated with standard surgical procedures for CIN 2/3 and the tissue removed was examined.

Women who received the vaccine were twice as likely as those who received a placebo to have their CIN eliminated, regardless of the type of HPV infection. The most striking results were the most striking in cases of CIN3 more severe: at least 15% and up to 36% of those who received the vaccine saw their CIN3 eliminated, while none of the women from the placebo group did not do it.

The researchers followed the participants for another two and a half years after the surgery, the longest study ever conducted by women in these trials. They showed that long-term follow-up was better for those who had received the vaccine compared to placebo, with more women in the vaccinated group remaining completely free of HPV. The study is published in Gynecologic oncology.

Harper notes that the therapeutic vaccine, called Tipapkinogen Sovacivec, or TS, is completely different from Gardasil9, the vaccine used to prevent HPV infection. Although Gardasil9 prevents infection with HPV, TS removes tissue already infected with HPV. CIN2 and CIN3 are always caused by high-risk HPV infections.

The typical treatment procedure for CIN2 or CIN3 involves removing a portion of the cone-shaped uterine cervix, called PNEA or cone. This results in scars and a shortened cervix, which can cause problems during delivery and increase the risk of caesarean section. In addition, women who undergo this procedure are at a very high risk of developing cervical cancer over the next 20 years if they do not continue their screening.

"The surgical procedure removes all the tissue that is heading for cancer, but does not eliminate all HPV.You are not homeless.You still have HPV," says Harper Rogel Cancer University of Michigan Center and Senior Associate Director of the Michigan Institute for Clinical and Health Research (MICHR).

With the vaccine, researchers found that it eliminated not only lesions, but also HPV infection.

"It actually deals with the cause of the disease, HPV," Harper said.

Women who received the vaccine injections reported sometimes severe reactions at the injection site. Harper says it was planned because the vaccine is designed to trigger the immune system. An immune reaction is likely to ignite the skin.

The study focused solely on cervical lesions, but HPV is badociated with several other types of cancer, including head and neck cancers and anus cancer. The researchers plan to test TS for these cancers in the future. Additional clinical trials are required before seeking TS approval from the US Food and Drug Administration. No trials are currently available.