Otago University scientists have taken a first step towards what could eventually be a Keytruda-type drug to fight cervical cancer.
They have identified one protein in the human papillomavirus (HPV) which suppresses the body's T-cells which normally fight cancers naturally.
Their discovery may help to develop a new drug which may do for cervical cancer what the recently approved drug Keytruda has done for skin cancer - blocking the molecules that suppress the cancer-fighting T-cells.
"It's important because it provides some of that basic understanding that can lead to those types of drugs that may allow us in the future to treat women with cervical cancer," said Associate Professor Merilyn Hibma, the research leader.
But she said it took 20 years from the first patient being treated with Keytruda to get that drug on to the market, so it could take decades to develop a similar treatment for cervical cancer - and potentially for other cancers.
"Potentially the mechanism may be broader than only HPV [the main precursor to cervical cancer]," she said.
"The same mechanism could potentially apply to other cancers, but we don't understand what that suppressant mechanism is. Until we understand that mechanism, we can't say that."
HPV infections are very common, infecting 50 to 80 per cent of all sexually active men and women at some point in their lives.
The body's immune system naturally fights off the infections in the vast majority of cases, but the virus persists in 10 to 20 per cent of cases and sometimes develops into cancer.
About 160 women develop cervical cancer every year, and about 50 die from it.
Since 2008 all girls in New Zealand have been able to get free injections from year 8 in intermediate school (about age 12) which prevent HPV in most cases. Pharmac decided in July to start funding the vaccine for boys as well as girls up to age 26.
The Otago research was done in mice and was mainly carried out by a Malaysian doctoral student, Khairunadwa Jemon, who is now teaching at a Malaysian university.
Hibma said the Otago team was now researching how the body's immune system is activated and how the E7 protein suppresses the cancer-fighting T-cells.