GDNF trial: a miracle cure?

In February, UK TV channel BBC Two aired ‘Parkinson’s Drug Trial: A Miracle Cure?’, a two-part documentary following the journey of nine people with Parkinson’s taking part in a medical trial.

We caught up with three of the participants to discuss the experience, what scared them the most – and why clinical trials are essential if we are to build a future without Parkinson’s

The multimillion pound GDNF clinical trial received global media attention earlier this year for offering hope that it may be possible to restore cells damaged by Parkinson’s.

The study, funded by Parkinson’s UK and The Cure Parkinson’s Trust and launched in 2012, aimed to reverse the effects of Parkinson’s. As part of the trial, 42 participants underwent brain surgery, with half being injected with glial cell-derived neurotrophic factor (GDNF) – a special protein that is naturally produced by the brain to protect cells – and half receiving a placebo for the first phase of the study.

The trial was followed by UK television channel BBC Two, and was aired in a two-part special in February 2019. We caught up with three participants, Vicki Dillon, 47, Darren Calder, 51, and Kay Cotton (pictured above), 57, about their experience – and whether or not the treatment improved their Parkinson’s symptoms.

What made you decide to volunteer for the GDNF trial?

Vicki Dillon: I used to be a nurse, so I was always interested in the medical side of my condition. I’ve also always been proactive. After I was diagnosed, I didn’t want to sit in a corner and wallow, I wanted to do something about it.

Kay Cotton: The GDNF trial came at a time when I was feeling like I didn’t have a purpose. When I saw the opportunity, I thought ‘I can do this’. It felt like I was being called to take part.

Darren Calder: It may sound crazy, but I’ve always believed that I have Parkinson’s for a reason – that there’s a purpose.

Dr Alan Whone (the principal investigator of the trial) was my consultant and he asked me if I would like to take part. I immediately knew the answer would be yes, because I wanted to try and make a difference.

What were your fears about the trial? 

Vicki: My fears were not about the dangers, but more that overall the trial would fail. Sadly, those fears were realised.

Darren: I had to undergo two operations to get the delivery system working correctly. I worried that if the GDNF didn’t work, I would be left worse off with my Parkinson’s. I kept these feelings to myself as I had a huge amount of faith in the team around me.

Kay: My main fear was the surgery itself and the possible side effects.

Darren Calder took part in the five-year GDNF trial that was televised on UK channel BBC Two.

What exactly did the GDNF trial involve?

Vicki: It involved invasive brain surgery, monthly infusions and assessments for which you had to come off medication. In short, you handed your life over on a plate to the team. Total dedication was needed.

Darren: I had to attend the hospital every month to receive an infusion into my brain. I had to carry out many assessments both off and on my medication, and give factual feedback on how I was feeling and whether there had been any notable improvements.

When did you start to feel any improvement in your symptoms after receiving GDNF?

Vicki: I noticed improvements after the second infusion! I felt better, I had more energy and better spatial awareness.

Darren: The improvements for me were enormous. GDNF quite frankly turned my life around, and although my DBS (deep brain stimulation) is now working brilliantly for me, I would have it all removed if I could get GDNF back.

Kay: I was convinced I was receiving GDNF from the start of the trial, I could see myself getting faster at the tests we had to do, and I could do things I hadn’t been able to do for a long time – things like sewing, doing up my shoe laces and buttoning a shirt. I generally had a lot more movement in the first nine months. My sense of smell also came back, it was fantastic to smell flowers again.

Do you think it is important for people in Parkinson’s community to volunteer for clinical trials?

Vicki: I would definitely encourage others to take part in clinical trials. It’s not everybody’s cup of tea, but you owe it to yourself and others. If nobody did it, we wouldn’t get anywhere. One day, I hope we can say that Parkinson’s is something that we used to have.

Darren: I would absolutely recommend taking part in clinical trials. Without the commitment of trial participants, treatments and cures would never advance. I always tell myself: “He who is not courageous enough to take risks will accomplish nothing in life.”

Kay: I took part for myself, but also for future generations. I have a son and grandchildren and I don’t want them to ever have to live with Parkinson’s.

Vicki Dillon, a participant in the groundbreaking televised GDNF trial says, “It has opened hearts, minds and eyes”.

What was the hardest part?

Vicki: Some parts of the trial were really hard for me for reasons that had nothing to do directly with the trial. Just before it started, I lost my mum, but that was actually one of the things that made me want to go on with it – I wanted to make the most of my life.

Darren: The hardest part of the trial was losing Tom Isaacs, he was our figurehead and a true champion, a complete inspiration to me.

Kay: I found it really difficult living on my own. I needed to clean the port (through which the GDNF is delivered) every day, which involved holding a mirror as well as trying to clean it. With my tremor it was impossible.

Do you think the documentary has helped to raise awareness about Parkinson’s?

Vicki: Definitely. It has opened hearts, minds and eyes.

Darren: I think the documentary will continue to raise awareness of Parkinson’s for many years to come. It is such a misunderstood condition and I am truly grateful to the filmmakers for the way they portrayed the trial so accurately.

Kay: Yes, people need to know about the hidden side of Parkinson’s. It is very difficult to step into view with this unpredictable condition, it’s much easier to hide.

You can watch the documentary here.

Image credit: Parkinson’s UK

Read more:

From diagnosis to clinical trial: my worldwide Parkinson’s journey

Could robots replace animals in Parkinson’s medical trials?