Marine sponge vaccine will 'hunt, kill tumours'
A melanoma vaccine to be tested on humans for the first time in Wellington could open the door to better cancer treatments that use the body's immune system to fight tumours.
After five years of research and $4.5 million spent, Associate Professor Ian Hermans will see his work at the Malaghan Institute put to the test from next month.
"We've had chemotherapy and we've had radiotherapy and surgery, and they've all been useful and effective to some degree," he said. "But there hasn't been a big new treatment modality for a long time, so that's why people are excited. I think the real excitement will be how we slot it into some of these existing treatments."
A key synthetic ingredient of the vaccine is based on a natural product discovered in marine sponges 10 years ago.
Dr Hermans believes this ingredient will boost the immune system's response to cancer by activating T cells in the blood to hunt out and kill tumour cells.
Half of the trial patients will receive a potent version of the vaccine containing the marine sponge derivative, and half will receive a vaccine without it. "What we're actually measuring is the size of the immune response that the vaccine generates. We can count the number of T cells that have anti-tumour activity."
All going well, the vaccine will be refined in the laboratory with the ultimate aim of creating a synthetic "off-the shelf" version that does not involve taking cells from individual patients and mixing them with manufactured ingredients.
The trial fits in with other research at the Malaghan Institute on how the immune system can be used to attack cancer from within. "It's a really exciting time to be in this area," Dr Hermans said.
Melanoma survivor Sarah Wilson, of Waikanae, said it was one of the "few sources of hope" as there had not been any giant leaps in melanoma treatment for several decades. Surgery worked for her back in 1999 and the melanoma was caught before it spread. "Mine was tiny, it was the size of a head of a pin, just really black. I've got a scar on my knee of about 7 to 8 centimetres."
Dr Hermans said manufacturing the vaccine had been a nationwide project involving Callaghan Innovation, Cancer Trials New Zealand and the University of Auckland.
Capital & Coast District Health Board is also involved, as people will receive the vaccine at Wellington Hospital.
Just over 40 people will be recruited from next month to take part in the trial, which is expected to take two years to complete.
Participants will have to meet strict criteria, including a history of successfully treated melanoma.
Cancer Society chief executive Dalton Kelly said research into new treatments was always welcome. "It won't just be one thing that resolves cancer, there are many types of cancer and we need to be working on them."
New Zealand has one of the highest rates of melanoma in the world - about 300 people die each year from the most aggressive type of skin cancer.
HOW THE VACCINE WORKS
Dendritic immune cells will be removed from a patient's blood and mixed with synthetic protein fragments that are common to melanomas. A glycolipid called alpha-galactosylceramide will be added – this is a synthetic version of a natural product found in a marine sponge.
The vaccine will be left in the laboratory for a few days before being injected into the patient. Lead researcher Ian Hermans believes the synthetic version of alpha-galactosylceramide will make the vaccine more potent by activating specific T cells that kill tumours.
"The dendritic cells are like the generals of the army who just come along and instruct the immune system to get out and recognise cells that have got these unique cells in them. The cells that do the dirty bits, the killing, that's the T cells.
"They can actually pick out a tumour cell and kill it and leave normal cells inside it intact."
The Dominion Post