In an early trial, an experimental vaccine was shown to trigger an immune response to attack HPV types that are known to cause nearly all cervical cancer precursors. Photo by huntlh/Pixabay

April 4 (UPI) -- Researchers have come up with a new therapy that wiped out a one-third HPV infections and lesions in women participating in a clinical trial, new research shows.

The therapeutic shot -- known as Tipapkinogen Sovacivec, or TS -- infuses a protein that activates an immune system response to combat high-risk HPV lesions, according to a study published Thursday in Gynecologic Oncology.


"There are very few products trying to cure women who already have an HPV infection," Diane Harper, a researcher at Michigan Medicine and study author, said in a news release. "It's very exciting. This is the first time we've seen something with this success rate that is relatively easy to implement."

Cervical precancerous lesions have three levels of severity: CIN 1, which normally go away without treatment; CIN 2, which can frequently go away on their own but at times advance to CIN 3 lesions. Within 30 years, just under half of CIN 3 lesions will turn cancerous.

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The study included 192 women who had either CIN 2 or CIN 3 lesions, with 129 receiving the vaccine while the rest of the women received placebos.

To treat HPV, women with CIN 2 or CIN 3 lesions normally have a piece of their cervix removed which leaves scarring and can cause complications during childbirth.

"The surgical procedure removes all the tissue that is headed towards cancer, but it doesn't remove all the HPV. You're not home-free. You still have HPV," Harper said. "It actually treats the cause of the disease, which is HPV."

Women who got vaccinated had twice the chance of getting any type of CIN removed than those who just got the placebo. However, women with CIN 3 were between 15 and 35 percent likely to have that type of lesion removed by the vaccine than women in a placebo group.

"We have no way to determine which women with CIN 3 will progress to cancer and which women will not. So we treat all women with CIN 2 or 3 as if they are likely to develop cancer," Harper said.