For years now, the human papillomavirus (HPV) vaccine Gardasil9 has been a safe, effective way to prevent HPV and, therefore cervical cancer, in women — but now a potential new vaccine could get rid of the virus and precancerous cells after you already have them.
In a clinical trial, researchers used the immune-based therapeutic injection on precancerous cells in the cervix, and one-third of the women treated were completely cured of the precancer and the underlying HPV infection.
The shot contains a protein that activates the immune system against high-risk types of HPV that can lead to cervical cancer, according to the study published in Gynecologic Oncology.
"There are very few products trying to cure women who already have an HPV infection," says study author Diane Harper, M.D., professor of family medicine and obstetrics and gynecology at Michigan Medicine, in a press release. "It's very exciting. This is the first time we've seen something with this success rate that is relatively easy to implement."
Precancerous lesions in the cervix are divided into three categories based on their severity:
- CIN 1 which usually go away on their own without treatment.
- CIN 2, which may clear up on their own but may also progress to the next stage.
- CIN 3, the most severe, which may become cancer over time.
Women with CIN 2 and CIN 3 were involved in the study: 129 women received the vaccine, and 63 received a placebo. Once a week for three weeks, women got a shot of the vaccine in the thigh. There were some women who had severe inflammation at the injection site, but that’s to be expected with immune reactions, Harper said.
After six months, cervical tissue was examined — and the results were overwhelmingly positive: Women who got the vaccine were more than twice as likely to be cured of their CIN, along with the HPV that caused it. For the women with CIN 3, as many as 36 percent who got the vaccine no longer had the precancer; for those with CIN 2, 33 percent were cleared. None of the women with CIN 3 in the placebo group saw their CIN eliminated.
Two and a half years later, long-term follow-up was also better for women who received the vaccine than for those who received the placebo — the vaccinated women were more likely to remain completely clear of HPV.
The new vaccine, called Tipapkinogen Sovacivec (TS), gets rid of tissue already infected with HPV (along with the HPV itself) — not to be confused with Gardasil9, the existing vaccine that can prevent HPV from occurring in the first place.
While the success of this vaccine is encouraging news, it will be a while before the TS vaccine will be available publicly. Researchers need to do additional clinical trials before the U.S. Food and Drug Administration considers approving the vaccine.
Treatment options for cervical cancer that are available now include:
- Surgery to remove the cancer
- Chemotherapy, which uses drugs to stop and kill cancer cells
- Radiation therapy, in which radiation destroys the cancer cells
- Immunotherapy, which uses your immune system to attack cancer cells
- Targeted therapy, or when drugs or other substances fight cancer cells, leaving healthy cells unharmed
The type of treatment you receive depends mainly on the stage of your cancer, according to the National Cancer Institute.