An image of some reoviruses

Researchers are investigating whether modified reoviruses could help treat cancer (image from Wikipedia)

Over the last week or so, we’ve received a lot of enquiries to our helpline and email service about a new experimental cancer drug called reolysin. This followed several reports in the national press the week previously.

Reolysin is a relatively new drug developed from a fairly harmless type of virus called a reovirus. Most of us will have been infected with one type of reovirus or another at some point.

In most normal healthy cells, reoviruses don’t usually cause problems, but scientists have found that they reproduce in some types of cancer cell, killing them in the process. Not only that, but it seems this process also helps the body’s immune system to recognise cancer cells and attack them.

Like all new discoveries, reolysin will have to be rigorously tested to prove that it‘s safe and has a lasting effect. Many potential new treatments that look really promising in the laboratory either don’t work in people, or turn out to be no better than the treatments we already have.

Early days

The media headlines were driven by the results of an early phase trial with reolysin, which was published in the journal Clinical Cancer Research. In this trial, the drug was given with other treatments like radiotherapy and chemotherapy.

The trial was small, and was trying to establish if the drug was safe and if it had any effect on tumours in humans. Only 23 patients took part, but 14 of them seemed to show a response to the treatment – their tumours either stopped growing or shrank.

But so far, the progress of these patients has not been followed for very long. Larger trials are needed to find out if the effects seen in this trial were genuinely down to reolysin, or due to the other treatments the patients were receiving. Researchers also need to find out whether the effects of reolysin on cancers are long lasting, and to compare it with other treatments to see which is best.

As is often the case with research, it’s likely to be a few years before we know the answers to these questions. If these trials are successful, it will be longer still before the treatment becomes widely available, as the drug will need to be evaluated by medical regulators like the National Institute for Health and Clinical Excellence. We don’t know of any trials currently going on that people can join.

The journalists did a good job in reporting accurately on this drug. All the articles we read made it clear that the treatment wasn’t available yet and that the long term effects were unknown – although, as is often the case, the headline writers at some newspapers may have got a bit over-excited.

Wider impact

But reading about potential breakthroughs can have quite an impact on some people with cancer, especially those whose cancer cannot be cured. We had a lot of calls to our helpline from people who wanted to know if they could get hold of the drug, or join a trial.

Our nurses are skilled at responding to these types of enquiries. Even if people are very distressed or desperate for some hope, they are able to help them come to terms with the fact that a new drug or treatment they’ve read or heard about isn’t available yet, and that we don’t yet know how well it works.

The nurses who write for our website CancerHelp UK also had the page on reolysin updated the day the story broke, giving people with questions about it somewhere to go for reliable information. The website also has a database of clinical trials that people can look through to see if there are any trials that they might be able to join (although there aren’t any reolysin trials recruiting at the moment).

It is really important that the public get to hear about new developments in cancer treatment. It helps to give hope and shows that scientists and clinicians are really making progress. But it’s also important that organisations like us provide services like our helpline and patient information website. With empathy and compassion, we can help people understand what the significance of a new discovery is.

You can call our nurses on freephone 0808 800 4040 from 9am till 5pm Monday to Friday.


Martin Ledwick manages Cancer Research UK’s information nurses


Harrington, al (2010). Two-Stage Phase I Dose-Escalation Study of Intratumoral Reovirus Type 3 Dearing and Palliative Radiotherapy in Patients with Advanced Cancers Clinical Cancer Research, 16 (11), 3067-3077 DOI: 10.1158/1078-0432.CCR-10-0054