UK-based ReNeuron have filed their first Investigational New Drug (IND) application with the US Food and Drug Administration (FDA) for ReN001, a stem cell therapy for stroke. If the application is approved, the company will begin Phase I clinical trials for the world's first stem cell treatment for a major neurological disorder.
Over 850,000 people suffer from a stroke each year in the US and UK. A third of those will be left with some form of permanent disability; making stroke is the single largest cause of adult disability in the developed world.
Currently, there are no treatments aimed at the causes of their disability. Instead, therapy is primarily based on the prevention of recurrent strokes. A stem cell treatment would be a major breakthrough because it would be able to repair some of the damage done by the stroke.
Stem cells have three properties that distinguish them from other types of cell. They are unspecified cells with no particular function and can go through many cycles of cell division over long periods of time. Finally, they can differentiate themselves into any specific cell types found in the body.
ReNeuron concentrate on producing somatic stem cell lines. These are cells that have already begun to differentiate into specific cell types. This type of tissue-specific cell is used because embryonic stem cells have been linked with forming tumours when transplanted. ReNeuron believe that somatic cells are therefore likely to be the safest form of stem cell to use in clinical applications.
The company use their patented c-mycER technology to generate the stem cell lines. The company believe this method is superior to rival technologies because it can generate genetically stable clonal stem lines.
"We can take any tissue derived stem cell and expand it up to a clonal line. There are a million possible doses [of ReN001] already made up," John Sinden, chief scientific officer at ReNeuron, told DrugResearcher.com.
The initial Phase I trial will run for 24 months and as well as monitoring the safety of the treatment, the length of the trial means that initial efficacy data can also be recorded. In addition to this data on therapeutic potential, Sindon said that the trial will also record MRI scan data and use cognitive measures and quality of life surveys to gain a fuller overview of the treatment.
It is unknown as to whether tem cell therapies can repair the whole region of stroke damage in the brain or, as is more likely, just the periphery.
Sinden said: "We will be looking at people who have had a stroke within the last 3 to 12 months and who have a stable level of disability that isn't going to improve spontaneously. We're hoping to regenerate the area of damage through the injection of stem cells."
"Ultimately, it is our goal to develop a therapy that can assist in repairing the whole area of damage."
Sinden went on to point out that because stroke has such a diversity of symptoms, that it is difficult to predict the range of effects a treatment such as this could have.
With this in mind, ReNeuron participates in a research project funded by the National institute of Health (NIH) called the Quantum Grant Programme. The project aims to engineer cell-based units that can be implanted into stoke patients and provide a source of neural and vascular cells to repair damage.
Earlier in the year, Renovis, a US biotechnology company announced that their neuroprotective drug, aimed at reducing the after-effects of a stroke, failed its Phase III clinical trial. The drug was developed in conjunction with AstraZeneca.
In their interim results for the six months ending in September, ReNeuron announced losses of £3.2m (€4.7m). The company hope that in the future, revenue from non-therapeutic commercial products can drive forward their research. For example, stem cells can be used in drug discovery to establish the toxicity of drugs or as a raw material in the manufacture of vaccines.