Immunotherapy: puzzles and promise

Immunotherapy works by harnessing the power of our own immune system to attack and kill cancer cells – something it normally does, but that cancer can interfere with. It’s also a promising alternative to less targeted options like chemotherapy that we’ve become familiar with.

How did this deceptively simple-sounding idea of using our own cells to treat cancer come about?

Then, in the 1890s, the surgeon William Coley first tried to use mixtures of bacteria to make the immune system attack cancer. For this, he’s recognised as the father of immunotherapy, although some problems with infection (perhaps unsurprisingly) arose from his otherwise innovative plan.

The challenges

Despite justifiable optimism, we still have to overcome some big hurdles before immunotherapy starts to show the same benefits we’ve seen from more established treatments like radiotherapy.

First, advances in immunotherapy aren’t helping everyone yet. It’s been transformative for a fortunate minority, so the next step is to make sure immunotherapies work against more cancer types and for more people.

Second, the immune system is powerful and potentially dangerous. Auto-immune diseases like multiple sclerosis, psoriasis and rheumatoid arthritis happen when our immune system doesn’t know when to quit. Overreactions to infections can cause coma or even be fatal. So, if we can boost our immunity to attack tumours, we also need to make sure it doesn’t spiral out of control or last too long.

Third, solid cancers have proven much more difficult to treat with immunotherapy than blood cancers. Tumours can be like walled-off castles, blocking access to our army of immune cells. They can also exhaust immune cells so they can’t make a difference, or the tumour environment can be so full of obstacles blocking their function that they simply can’t do their jobs, even if they’re already inside.

This is where combination treatments come in, which could help overcome barriers to safe and effective immunotherapy. But these can also create more hurdles, particularly in terms of side effects, which can be severe and affect a lot of people.

It’s essential we fund more discovery research that helps us learn exactly what’s going on in different tumour types – and even inside individual tumours – so that personalised immunotherapies tailored to unique tumour environments can reach their potential and wipe cancer out.

Combining immunotherapies together or with other cancer treatments – even ones that haven’t showed very promising results to date – is also a promising strategy. In the 1990s, scientists thought that by cutting off tumour blood vessels using anti-angiogenic drugs, they could starve tumours – like killing a weed root-first. But the drugs’ performance was, unfortunately, disappointing.

Now, clinical trials are finding that anti-angiogenics can ‘normalise’ blood vessels growing into tumours, which can help ICI drugs to awaken immune cells. Immunotherapy combinations like this can even be effective against some late-stage cancers that have already spread, and metastasis remains one of the greatest challenges for cancer treatment.

Here’s a glimpse of the research we’re funding that’s helping to break through barriers to available, successful and safe immunotherapies.

Inside the toolbox

At a glance: our immunotherapy innovators

Understanding and predicting cancer’s trajectory

Learning details like this can be the key to overcoming treatment resistance through better drugs and new combination therapies.

Vaccines setting the immune system’s sights on lung cancer