PHOTO
Kiwi cancer patients have been at the forefront of an international trial that may revolutionise melanoma treatment.
Developed by drug companies Merck and Moderna, the vaccine Intismeran has been used alongside current immunotherapy treatment Keytruda among more than 1000 patients around the world, including 45 from New Zealand.
While the results of that trial are not yet available, medical oncologist and Melanoma NZ spokesperson Gareth Rivalland said earlier tests showed considerable promise.
“We don’t have the results of this big trial, but there was an earlier, smaller trial with 150 people that’s just had its five-year follow-up announced,” Rivalland said.
“We use these medications after someone’s had a high-risk melanoma removed, and we want to reduce the chance of it coming back and giving them trouble.
“If we think about our standard therapy, which the government funded about 18 months ago — Keytruda v a placebo — that reduced the chances of this coming back by about 40%.
“If you add on the mRNA vaccine to Keytruda, that reduces it by a further 50%, so it looks like the early information held a lot of promise.”
Rivalland said the results of the worldwide trial would be available in September. About 40 of those participants were based in Auckland.
“Melanoma is very common in New Zealand and it was a real privilege to have people part of this cutting-edge therapy,” he said.
“Interestingly, the thing we always worry about with any of these new medications is will it increase side-affects, what is the quality of life like and, for the majority of people, we really haven’t seen a ramp-up of nasty side-effects.
“Potentially, we’ve got something really beneficial without the side-effects and that’s the type of treatment we’re looking for.”
Rivalland described the process involved in treating cancer.
“One of the things cancers have to do to become a cancer and spread and move and give us the trouble we all know about, they have to find a way around the immune system,” he said. “One of the jobs of your immune system is to go around taking out these rogue cells before they turn into cancer.
“Since the 1980s, people have been trying to vaccinate against the cancers, telling the immune system, ‘please go and look for these things’, but we didn’t realise the cancer had already found a way to escape the immune system.
“Medications like Keytruda, as it’s branded, unmask the cancer and allow your immune system to see the cancer cells, attack and then kill them.
“Keytruda has been a real revolution and this whole idea of immunotherapy using the immune system to treat cancer has changed melanoma, lung cancer, bladder cancer over the past 15 years, but as those successes have come through, people have wondered if there was something around the immune system still not able to see the cancer cells and therefore the vaccine came back into view.
“If we combine the vaccine with this unmasking drug like Keytruda, are we going to get a better response? This is what this groundbreaking 1000-plus person trial has shown us.”
Rivalland thinks this treatment may benefit 300-400 NZ cancer sufferers.
“Obviously, we have no idea of costs, but there’s a potential to be curing people much earlier, and that knock-on effect where people are developing stage 4 disease or have it be life-threatening.
“That’s really what we’re trying to do. This treatment is pushing that ambulance up the cliff, so as a country, we’re dealing with far fewer people at that more significant stage of illness.”
The treatment may also be the key to combatting other forms of cancer.
“We’ve been involved, using this mRNZ technology for lung cancer and other types of skin cancer, and we have a trial now for stage 4 melanoma using this technology,” Rivalland said.
“That horse has already bolted — the early promise has been lived up to now and we hope it will be a gamechanger against multiple different cancers.
“Common cancers like breast cancer or bowel cancer tend to respond less well to our current immunotherapies, so the big question is can something like this mRNA technology change the game for those really common, really important cancers that are becoming more frequent?”