In 2013, a biotech company called Ceregene reported disappointing results from their experimental gene therapy clinical trial for Parkinson’s. The data from the study suggested that the therapy had no clinical effect on the progression of Parkinson’s (Click here to read the press release).
Today, however, researchers associated with that biotech company have published a new report that suggests that the treatment had beneficial effects in the brain, but not enough of it was delivered.
The treatment was a gene therapy approach (which involves using DNA rather than drugs to treat medical conditions), and it involved a protein called neurturin.
In today’s post, we will discuss what neurturin is, we will review what this new study found, and consider what the implications could be for future gene therapy trials in Parkinson’s.
Reanalysing clinical trial data (called post-hoc analysis) provides a very useful way of generating new hypotheses even if the initial study did not reach its primary endpoint (that is to say the study did not demonstrate a successful outcome. Post-hoc analysis must be handled carefully, as the findings of such investigations can be viewed as selective ‘cherry picking’ of interesting outcomes. They will need to be tested to determine if they are real effects.
Even more important than post-hoc analysis, however, is following up participants who took part in a trial to see if there were any long-term benefits from the treatment. I often wonder how much important data is lost after a clinical trial simply becomes there is no long term follow up and study investigators lose track of participants as they drift away.
Precious nuggets of information can be gained from long-term analysis. And this week we saw a really interesting example of this.
Here is the research report:
Title: Long-term post-mortem studies following neurturin gene therapy in patients with advanced Parkinson’s disease.
Authors: Chu Y, Bartus RT, Manfredsson FP, Olanow CW, Kordower JH.
Journal: Brain. 2020 Mar 1;143(3):960-975.
PMID: 32203581 (This report is OPEN ACCESS if you wouldl like to read it)
In this study, the researchers were looking at postmortem brain sections from 2 participants who took part in a clinical trial investigating a treatment called neurturin.
What is neurturin?
Today – 27th February, 2019 – the long-awaited results of the Phase II GDNF clinical trial were published.
GDNF (or glial cell line-derived neurotrophic factor) is a protein that our bodies naturally produce to nurture and support cells. Extensive preclinical research suggested that this protein was particularly supportive of dopamine neurons – a group of cells in the brain that are affected by Parkinson’s.
The results of the Phase II clinical trial suggest that the treatment was having an effect in the brain (based on imaging data), but the clinic-based methods of assessment indicated no significant effect between the treatment and placebo groups.
In today’s post we will look at what GDNF is, review the previous research on the protein, discuss the results of the latest study, and look at what happens next.
And be warned this is going to be a long post!
Boulder, Colorado. Source: Rps
It all began way back in 1991.
George H. W. Bush was half way into his presidency, a rock band called Nirvana released their second album (‘Nevermind’), Michael Jordan and the Chicago Bulls rolled over the LA Lakers to win the NBA championship, and Arnold Schwarzenegger’s ‘Terminator 2’ was the top grossing movie of the year.
But in the city of Boulder (Colorado), a discovery was being made that would change Parkinson’s research forever.
In 1991, Dr Leu-Fen Lin and Dr Frank Collins – both research scientists at a small biotech company called Synergen, isolated a protein that they called glial cell-derived neurotrophic factor, or GDNF.
And in 1993, they shared their discovery with the world in this publication:
Title: GDNF: a glial cell line-derived neurotrophic factor for midbrain dopaminergic neurons.
Authors: Lin LF, Doherty DH, Lile JD, Bektesh S, Collins F.
Journal: Science, 1993 May 21;260(5111):1130-2.
For the uninitiated among you, when future historians write the full history of Parkinson’s, there will be no greater saga than GDNF.
In fact, in the full history of medicine, there are few experimental treatments that people get more excited, divided, impassioned and evangelical than GDNF.
This ‘wonder drug’ has been on a rollercoaster ride of a journey.
What exactly is GDNF?
This week a biotech company called Voyager Therapeutics announced the results of their ongoing phase Ib clinical trial. The trial is investigating a gene therapy approach for people with severe Parkinson’s disease.
Gene therapy is a technique that involves inserting new DNA into a cell using a virus. The DNA can help the cell to produce beneficial proteins that go on help to alleviate the motor features of Parkinson’s disease.
In today’s post we will discuss gene therapy, review the new results and consider what they mean for the Parkinson’s community.
On 25th August 2012, the Voyager 1 space craft became the first human-made object to exit our solar system.
After 35 years and 11 billion miles of travel, this explorer has finally left the heliosphere (which encompasses our solar system) and it has crossed into the a region of space called the heliosheath – the boundary area that separates our solar system from interstellar space. Next stop on the journey of Voyager 1 will be the Oort cloud, which it will reach in approximately 300 years and it will take the tiny craft about 30,000 years to pass through it.
Where is Voyager 1? Source: Tampabay
Where is Voyager actually going? Well, eventually it will pass within 1 light year of a star called AC +79 3888 (also known as Gliese 445), which lies 17.6 light-years from Earth. It will achieve this goal on a Tuesday afternoon in 40,000 years time.
Gliese 445 (circled). Source: Wikipedia
Remarkably, the Gliese 445 star itself is actually coming towards us. Rather rapidly as well. It is approaching with a current velocity of 119 km/sec – nearly 7 times as fast as Voyager 1 is travelling towards it (the current speed of the craft is 38,000 mph (61,000 km/h).
Interesting, but what does any of that have to do with Parkinson’s disease?
Well closer to home, another ‘Voyager’ is also ‘going boldly where no man has gone before’ (sort of).