A new breakthrough in treating melanoma has been described as 'a real shot in the arm' for the development of tumour vaccines.
Drug companies Moderna and MSD say a vaccine treatment for the skin cancer has an overall survival rate of 96%.
A 157-patient trial showed that after two-and-a-half years, melanoma patients that had received the cancer vaccine combination had an overall survival rate of 96%, compared to 90.2% with cancer therapy Keytruda alone.
About 75% of the patients on the vaccine combination had a recurrence-free survival, compared to 55.6% on Keytruda alone.
MSD and Moderna, which have been collaborating since 2016, are also conducting a late-stage study of their vaccine and Keytruda combination.
Consultant Medical Oncologist Professor John Crown told The Hard Shoulder the vaccine can change depending on the patient's own tumour.
"It really is something to be excited about in the sense that it's the first real demonstration in an appropriately designed comparison study that a wholly new technology is improving outcomes compared to one of the standard treatments," he said.
"Somewhat unusual new technology [in] using the patient's own tumour to programme a vaccine that recognises that person's individual cancer and giving it together with another immunotherapy drug in producing better results".
'A bit to work out yet' on melanoma
Prof Crown said actual treatment for melanoma is likely sometime away.
"This is not a new treatment that people are going to be getting tomorrow or the next day," he said.
"The control arm of this study was a single immunotherapy drug - a good drug, a good actor drug.
"There are other combinations of drugs which are also somewhat superior to that in similar settings - so there will be a bit to work out yet.
"But it's a real - if you'll pardon the pun - shot in the arm for the whole concept of trying to develop tumour vaccines for patients".
A person is given a COVID-19 vaccine. Image: ANP / AlamyProf Crown said the COVID-19 pandemic likely helped to speed up the process.
"I think COVID and the COVID vaccine search helped really accelerate this whole process along too," he said.
"They take the patients tumour, they do a full sequence on the tumour.
"They're able to recognise mutations - areas where the genes in the tumour depart from normal - the pattern of these mutations would be different from cancer to cancer, from patient to patient.
"They are then able to programme a vaccine which would recognise the proteins that that would make".
'Holy grail'
Prof Crown said the immune system actually recognises a lot of foreign invaders such as melanoma.
"For decades the real holy grail was 'Could we use the immune system to fight cancer?'" he said.
"When we weren't able to do that successfully by the 1980s/1990s there was a depressing sense that perhaps the immune system - which was designed by nature to recognise foreign invaders in our body - was not designed to recognise our own cells if they misbehaved.
"In fact we were wrong: the immune system is well capable in many cases of recognising cancer as being something which should not be there."
Prof Crown said the reason the immune system doesn't eradicate cancer is down to "natural checks and balances".
"In one of those little quirks, the checks and balances which keep the immune system in check also help to protect cancer from the immune system," he said.
"The real incredible advance was discovering you could disable those breaks and let the immune system get working on cancer."
Prof Crown added that "every year" there seems to be more data coming out showing a benefit.
