An on-going clinical trial conducted by Living Cell Technologies Limited (LCT), a company based in New Zealand, has shown promising results to treat people with Parkinson disease using pig brain cell implants.
PARKINSON’S DISEASE OVERVIEW
Parkinson’s disease is a chronic and gradually progressive neurodegenerative disorder that affects locomotion and coordination. Most noteworthy symptoms include tremors, slow or lack of movements, impaired balance and coordination etc. This disease generally starts developing due to dying neurons in a brain region called substantia nigra. These neurons are primarily responsible for producing a chemical called dopamine which acts in different brain regions to control muscle movements.
More than 10 million individuals suffer from this neurological disorder worldwide. Moreover, it is one and half times more likely to affect men than women. Especially relevant is that in about 4% of patients, the age of disease onset is below 50 years.
SCIENCE BEHIND CELL THERAPY
The company developed an alginate coated capsule, NTCELL®, which contains pathogen-free neonatal cells from the choroid plexus in pigs. This particular brain region produces many growth factors and signaling molecules. Hence these are mainly responsible for regulating neural stem cells and maintain a healthy nervous system.
The notion of the clinical trial is to implant these capsules in the human brain, so that growth factors produced from these pig cells can excite healthy neurons to produce dopamine.
The company’s patented technology, IMMUPEL™, can help in this implantation. In addition, it allows packaging pig cells inside a protected capsule that prevent them from being rejected by the human immune system. The technology is beneficial to such cell therapies as there is no need to co-treat patients with immunosuppressive drugs.
LARGER CLINICAL TRIALS
The aim of any scientific study is to take it to the public. Consequently, this is where the company has already begun working. Phase I/IIa clinical study of NTCELL for treating Parkinson’s disease has already been completed in June 2015. Furthermore, with a primary aim to measure safety issues related to the cell therapy, the trial provided satisfactory results in 4 patients.
The trial involved implanting 40 capsules into the putamen. It is a brain structure associated with feedback control of limb movement, in one side of the brain.
Improvement in disease state measured using Unified Parkinson’s Disease Rating Scale showed promising outcome in all 4 patients 130 weeks after the surgery.
“Such sustained improvement is interesting and encouraging,” says Dr. Barry Snow, the principal investigator from the Auckland City Hospital.
However, further evaluation is necessary to eliminate possibilities of placebo effects. Since the effect could be patient’s belief in the treatment rather than the actual effect of the therapy.
According to Steven Gill from the University of Bristol, UK, results obtained from the trial could have been due to placebo effects since improvements are observed immediately after the surgery. “Nerve cells don’t regrow that fast,” he says.
He also suggests that such quick improvement might be due to patient’s overstatement on their symptom severities to get a place on the trial.
HOPE FOR THE PATIENTS
In March 2016, the company has started phase IIb clinical study. It is aiming to validate the most effective dose of cell therapy and evaluate possible placebo effects of the response.
“The results to date certainly validate the Phase IIb dose ranging study in progress, in which higher doses of NTCELL are implanted into the putamen on both sides of the brain and which includes a sham surgical-controlled placebo group,” Dr Ken Taylor, CEO of LCT, says.
In the on-going trial, 18 patients were operated to place 140 capsules in both sides of their brains.
On successful completion of the trial, the company plans to apply for provisional consent for treating patients with Parkinson’s in New Zealand.The futuristic technique using pig cells, which is still very early on in trials, shows promising signs as a potential new remedy
“Our goal, subject to continued satisfactory data, remains to obtain provisional consent and launch NTCELL. This could be the first disease modifying treatment for Parkinson’s disease in 2018,” says Dr Taylor.
Better treatment for Parkinson’s disease is on the horizon.