The annual conference of the American Society of Clinical Oncology (ASCO) is probably the largest gathering of cancer specialists in the world. Almost 30,000 experts assembled in Chicago over the weekend for arguably the most important meeting in the cancer research calendar.
In its 46th year, this year’s meeting has revealed some exciting results from clinical trials of new treatment approaches, as well as setting out the challenges that we must rise to if we are to beat cancer. Here are highlights of a couple of talks that caught our attention.
Long-awaited progress in treating advanced melanoma
There was a buzz around the results of a large-scale (phase 3) trial involving patients with advanced melanoma, the deadliest form of skin cancer. Although surgery is very effective at treating the disease in its early stages, the chances of surviving drop rapidly once the cancer has spread. And the incidence of melanoma has climbed faster than any other cancer type over the past few decades, probably due to excessive sun exposure and sunbed use.
Researchers have been interested in using immunotherapy to treat advanced melanoma for some years now, but many promising treatments haven’t lived up to expectations. Excitingly, this new trial showed that adding ipilimumab, an experimental immunotherapy drug, to a vaccine treatment (called gp100) extends survival beyond that seen with the vaccine alone.
Ipilimumab is a monoclonal antibody that activates the immune system’s T-cells, which then in turn seek out and destroy melanoma cells in the body.
While the benefits were modest – people given both treatments survived for 10 months on average, compared with just over 6 months for those receiving the vaccine alone – this is the first real progress in the treatment of advanced melanoma for thirty years. Against a backdrop of decades of failed trials, this landmark study feels like a new start in tackling this hard-to-treat cancer for which few treatment options currently exist.
Indeed, lead researcher Dr Steven O’Day, from the University of Southern California Keck School of Medicine in Los Angeles, said that this was “the first time that a treatment has been shown to improve survival in a phase 3 study for advanced melanoma”.
But the treatment isn’t without its problems. While patients generally tolerated ipilimumab well, the trial showed an increased risk of side effects, including inflammation of the colon and diarrhoea. Assuming the drug makes it into general usage, it will be important for doctors to follow up any patients receiving treatment to check for early signs of side effects and take prompt action to reduce them.
The researchers now plan to investigate ipilimumab further to see if they can bring more benefits to patients, for example by combining the drug with other treatments. And there are hopes that it could be applied to other cancer types. Ipilimumab has already shown some potential against prostate cancer, and Cancer Research UK is supporting a new study to test the drug in small cell lung cancer.
So after a long time, we hope we are now on the path towards being able to offer better treatments for people with this advanced form of skin cancer.
Advances in lung cancer treatment
It was encouraging to see lung cancer appearing as a hot topic at this year’s ASCO conference, with many researchers presenting results of recent clinical trials aiming to improve the current poor survival rates for the disease. Most of the focus has been on non-small cell lung cancer (NSCLC), which accounts for over three-quarters of all lung cancers.
Many studies presented at the conference looked at a set of drugs that target a protein called EGFR. Examples include erlotinib (Tarceva) and gefitinib (Iressa). Altered EGFR is an important driver in several cancers, including many lung cancers. Scientists are now working on how to target these treatments to the right patients, based on their molecular signature, and finding ways to tackle drug resistance.
One of the most exciting presentations on lung cancer related to a new experimental drug called crizotinib (PF-02341066) – a targeted treatment. Dr Yung-Jue Bang, professor at Seoul National University College of Medicine in Seoul, Korea, presented his results of a small-scale (phase 1) trial involving a very specific group of advanced NSCLC patients.
All the patients had an overactive version of a protein called ALK, which plays an important role in controlling cell growth and survival. The new drug works by blocking ALK, halting the growth of cancer cells.
The researchers saw impressive results for such an early stage study, with most of the patients responding to treatment to some extent. Dr Bang said “These results are quite dramatic, and represent an important improvement over what we would see with standard chemotherapy for patients with metastatic disease.” Scientists think that about one in 20 lung cancer patients have NSCLC with overactive ALK. They are a particularly hard group of patients to treat as they don’t appear to respond to current lung cancer treatments, including drugs that target EGFR mentioned above.
We have to remember that this was only a small study. The key will be to see if these kinds of responses are repeated in a large-scale trial, which is now under way. If it lives up to its early promise then crizotinib could become the standard of care for this particular group of lung cancer patients.
This study provides a taste of things to come as we move into the rapidly emerging era of personalised treatment. It shows what a difference we can make by targeting a drug to those patients most likely to benefit..
It’s also worth pointing out that this work has moved at a rapid pace. It only took three years to go from the discovery that ALK is overactive in NSCLC to starting early clinical trials of the drug – breakneck pace in the world of research, and a sign that scientists all over the world are making real progress in beating cancer.
Helen George, Head of Science Information at Cancer Research UK