Revolutionary cancer vaccine trials inspired by COVID jab begin
Initial trials in mice show that the vaccine can shrink tumours and increase survival rates.
The team behind the Oxford-AstraZeneca COVID-19 vaccine have used the same techniques to create a vaccine that could potentially ‘revolutionise’ cancer treatment.
The researchers have designed a two-dose cancer vaccine using the same viral vector technology used in the Oxford COVID vaccine to increase the levels of anti-tumour T cells and shrink tumours in mice. The vaccine targets specific structures, known as MAGE proteins, found on the surface of many cancers.
“We knew from our previous research that MAGE-type proteins act like red flags on the surface of cancer cells to attract immune cells that destroy tumours. MAGE proteins have an advantage over other cancer antigens as vaccine targets since they are present on a wide range of tumour types,” said Benoit Van den Eynde, Professor of Tumour Immunology at the University of Oxford.
“This broadens the potential benefit of this approach to people with many different types of cancer.
“Importantly for target specificity, MAGE-type antigens are not present on the surface of normal tissues, which reduces the risk of side-effects caused by the immune system attacking healthy cells.”
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When combined with existing anti-PD-1 immunotherapy treatments, the vaccine showed a greater reduction in tumour size and improved the survival of the mice.
Anti-PD-1 immunotherapy is a promising method of cancer treatment that works by ‘taking the brakes’ off anti-tumour T cells and inciting them to kill cancer cells. However, it has so far proven to be largely ineffective thanks in part to the low levels of T cells in the majority of cancer patients.
This is where the tech borrowed from the Oxford-AstraZeneca vaccine comes in – a two-dose treatment can help to boost the levels of cancer-fighting CD8+ T cells.
“Our cancer vaccines elicit strong CD8+ T cell responses that infiltrate tumours and show great potential in enhancing the efficacy of immune checkpoint blockade therapy and improving outcomes for patients with cancer,” said Prof Adrian Hill, Director of the Jenner Institute, University of Oxford.”
The team now plan to begin their first human clinical trial of the vaccine used in combination with anti-PD-1 immunotherapy in 80 patients with non-small cell lung cancer later this year as part of a collaboration between Vaccitech Oncology Limited (VOLT) and Cancer Research UK’s Centre for Drug Development.
“This new vaccine platform has the potential to revolutionise cancer treatment. The forthcoming trial in non-small cell lung cancer follows a Phase 2a trial of a similar cancer vaccine in prostate cancer undertaken by the University of Oxford that is showing promising results,” said Hill.
Reader Q&A: How does radiation kill cancer if it causes cancer?
Asked by: Odysseus Ray Lopez, US
It’s rather like the way guns can be used to commit crime, or stop it. Radiation causes cancer because its high-energy photons can cause breaks in the DNA strands in your cells. Cells can repair this damage up to a point, but sometimes the repair isn’t perfect and leaves some genes defective.
If the break affects one of the many tumour-suppressing genes in your DNA, that cell can become cancerous. But cancer cells are also more vulnerable to radiation than ordinary cells. Part of what makes them cancer cells is their ability to divide rapidly and this normally means that some of the DNA ‘spellcheck’ mechanisms are turned off.
So when a cancer cell suffers a break in a DNA strand, it’s less likely to repair it correctly. Depending where the break occurs, it might either kill the cell outright, or make it reproduce more slowly.
Radiation therapy uses a focused beam that is aimed at just the part of the body with the tumour, and the dose is carefully calculated to cause the minimum collateral damage to healthy cells. Even so, radiation therapy does very slightly increase your chances of developing a second cancer.
Jason is the commissioning editor for BBC Science Focus. He holds an MSc in physics and was named Section Editor of the Year by the British Society of Magazine Editors in 2019. He has been reporting on science and technology for more than a decade. During this time, he's walked the tunnels of the Large Hadron Collider, watched Stephen Hawking deliver his Reith Lecture on Black Holes and reported on everything from simulation universes to dancing cockatoos. He looks after the magazine’s and website’s news sections and makes regular appearances on the Instant Genius Podcast.