The biotech company Acorda Therapeutics Inc. yesterday announced that it was halting new recruitment for the phase III program of its drug Tozadenant (an oral adenosine A2a receptor antagonist).
In addition, participants currently enrolled in the trial will now have their blood monitoring conducted on a weekly basis.
The initial report looks really bad (tragically five people have died), but does this tragic news mean that the drug should be disregarded?
In todays post, we will look at what adenosine A2a receptor antagonists are, how they may help with Parkinson’s, and discuss what has happened with this particular trial.
Dr Ron Cohen, CEO of Acorda. Source: EndpointNews
Founded in 1995, Acorda Therapeutics Ltd is a biotechnology company that is focused on developing therapies that restore function and improve the lives of people with neurological disorders, particularly Parkinson’s disease.
Earlier this year, they had positive results in their phase III clinical trial of Inbrija (formerly known as CVT-301 – Click here to read a previous post about this). They have subsequently filed a New Drug Application with the US Food and Drug Administration (FDA) to make this inhalable form of L-dopa available in the clinic, but the application has been delayed due to manufacturing concerns from the FDA (Click here to read more about this). These issues should be solvable – the company and the FDA are working together on these matters – and the product will hopefully be available in the new year.
So what was the news yesterday?
Acorda Therapeutics has another experimental product going through the clinical trial process for Parkinson’s disease.
It’s called Tozadenant.
Tozadenant is an oral adenosine A2a receptor antagonist (and yes, we’ll discuss what all that means in a moment).
Yesterday Acorda Therapeutics Inc announced that they have halted new recruitment for their phase III clinical program. In addition the company is increasing the frequency of blood cell count monitoring (from monthly to weekly) for participants already enrolled in the company’s Phase 3 program of Tozadenant for Parkinson’s disease.
The Company took this action due to reports of cases of agranulocytosis.
The title of today’s post is written in jest – my job as a researcher scientist is to find a cure for Parkinson’s disease…which will ultimately make my job redundant! But all joking aside, today was a REALLY good day for the Parkinson’s community.
Last night (3rd August) at 23:30, a research report outlining the results of the Exenatide Phase II clinical trial for Parkinson’s disease was published on the Lancet website.
And the results of the study are good:while the motor symptoms of Parkinson’s disease subject taking the placebo drug proceeded to get worse over the study, the Exenatide treated individuals did not.
The study represents an important step forward for Parkinson’s disease research. In today’s post we will discuss what Exenatide is, what the results of the trial actually say, and where things go from here.
Last night, the results of the Phase II clinical trial of Exenatide in Parkinson’s disease were published on the Lancet website. In the study, 62 people with Parkinson’s disease (average time since diagnosis was approximately 6 years) were randomly assigned to one of two groups, Exenatide or placebo (32 and 30 people, respectively). The participants were given their treatment once per week for 48 weeks (in addition to their usual medication) and then followed for another 12-weeks without Exenatide (or placebo) in what is called a ‘washout period’. Neither the participants nor the researchers knew who was receiving which treatment.
At the trial was completed (60 weeks post baseline), the off-medication motor scores (as measured by MDS-UPDRS) had improved by 1·0 points in the Exenatide group and worsened by 2·1 points in the placebo group, providing a statistically significant result (p=0·0318). As you can see in the graph below, placebo group increased their UPDRS motor score over time (indicating a worsening of motor symptoms), while Exenatide group (the blue bar) demonstrated improvements (or a lowering of motor score).
Reduction in motor scores in Exenatide group. Source: Lancet
This is a tremendous result for Prof Thomas Foltynie and his team at University College London Institute of Neurology, and for the Michael J Fox Foundation for Parkinson’s Research who funded the trial. Not only do the results lay down the foundations for a novel range of future treatments for Parkinson’s disease, but they also validate the repurposing of clinically available drug for this condition.
In this post we will review what we know thus far. And to do that, let’s start at the very beginning with the obvious question:
So what is Exenatide?
In this post I review recently published research describing interesting new gene therapy tools.
“Gene therapy” involved using genetics, rather than medication to treat conditions like Parkinson’s disease. By replacing faulty sections of DNA (or genes) or providing supportive genes, doctors hope to better treat certain diseases.
While we have ample knowledge regarding how to correct or insert genes effectively, the problem has always been delivery: getting the new DNA into the right types of cells while avoiding all of the other cells.
Now, researchers at the California Institute of Technology may be on the verge of solving this issue with specially engineered viruses.
Gene therapy. Source: yourgenome
When you get sick, the usual solution is to visit your doctor. They will prescribe a medication for you to take, and then all things going well (fingers crossed/knock on wood) you will start to feel better. It is a rather simple and straight forward process, and it has largely worked well for most of us for quite some time.
As the overall population has started to live longer, however, we have become more and more exposed to chronic conditions which require long-term treatment regimes. The “long-term” aspect of this means that some people are regularly taking medication as part of their daily lives. In many cases, these medications are taken multiple times per day.
An example of this is Levodopa (also known as Sinemet or Madopar) which is the most common treatment for the chronic condition of Parkinson’s disease. When you swallow your Levodopa pill, it is broken down in the gut, absorbed through the wall of the intestines, transported to the brain via our blood system, where it is converted into the chemical dopamine – the chemical that is lost in Parkinson’s disease. This conversion of Levodopa increases the levels of dopamine in your brain, which helps to alleviate the motor issues associated with Parkinson’s disease.
Levodopa. Source: Drugs
This pill form of treating a disease is only a temporary solution though. People with Parkinson’s disease – like other chronic conditions – need to take multiple tablets of Levodopa every day to keep their motor features under control. And long term this approach can result in other complications, such as Levodopa-induced dyskinesias in the case of Parkinson’s.
Yeah, but is there a better approach?
Some researchers believe there is. But we are not quite there yet with the application of that approach. Let me explain: