ReNeuron’s stem cell line ReN001 to treat disabled stroke patients in human trials

ReN001 stem-cell line, a experimental therapy that offers great promise to rejuvenate brain cells in stroke patients developed by ReNeuron, has been approved for clinical studies by UK government.

ReNeuron has received regulatory and conditional ethical approvals to commence a Phase I clinical trial in the UK with its lead ReN001 stem cell therapy for disabled stroke patients.

ReN001 stem-cell line will be administered in patients who suffered stroke early next year.

ReNeuron will be the first biotechnology to trial the use of fetal stem cells for treating stroke in humans. The stem cells extracted from fetal blood has been successfully tested  in rodents.

Earlier, a few other companies have tried stem cells derived from a patient’s bone marrow, fetal pig brain cells or tumors grown from germ eggs and sperm to treat stroke patients with little success.

Last year, Cell Therapeutics Corp, which was running a human trial using patients’ stem cells to stimulate growth of new brain cells in stroke patients, was asked to stop trials by North American regulators on safety reasons.

ReNeuron’s ReN001 stem-cell has been grown from a tissue sample taken in 2003 from the brain of an aborted fetus.

Fetal stem cells are grown from tissue taken from a fetus, which an embryo becomes eight weeks after conception.

ReNeuron can grow all the cells needed for treatment from the single tissue sample, and no need for more fetuses reports said.

ReNeuron has modified ReN001 stem cell line with a gene called c-myc. c-myc, a gene linked to cancer, provides a gear that enables doctors to control the cells’ growth by adding or removing the drug tamoxifen.

ReNeuron will enrol only men in ReN001 stem cell line trial because the drug needed to activate or inactivate the c-myc gene which could pose risks for certain women.

However, women stroke patients could be added in ReN001 stem cell line trial at a later stage.

ReNeuron is developing stem cell therapies for a number of other conditions, including peripheral arterial disease and diseases of the retina.

ReNeuron Group plc reported positive pre-clinical efficacy data with its ReN009 stem cell therapy for peripheral arterial disease (PAD) in November.

PAD is a chronic and debilitating disease that progressively restricts blood flow in the limbs, causing cramping, chronic pain and in extreme cases, loss of limb.  PAD is commonly associated with other conditions such as diabetes, obesity and stroke.  At least 1 in 20 people over the age of 55 have some degree of PAD and it becomes more common with increasing age.

In two studies, the researchers tested ReNeuron’s lead CTX neural stem cell line, via intramuscular injection, in a recognised murine hind limb ischaemia model.  A range of doses were used across the studies, from 3,000 to 3 million cells per treatment.

A significant and dose-dependant recovery of blood flow to the ischaemic limb was seen as soon as three days after ischaemia, with significantly increased revascularisation of the damaged tissue after 21 days, as measured by increased capillary and arteriole density.

The results of the above studies were presented by poster at the American Heart Association Scientific Sessions 2009 in Orlando, Florid.  An AHA Scientific Council travel stipend has been awarded to the Bristol team poster presenter in recognition of the scientific excellence of the abstract submitted to the Scientific Sessions.

ReNeuron is developing its ReN009 therapy as an allogeneic (non-patient specific) stem cell treatment for late-stage PAD, or critical limb ischaemia, in diabetic patients for whom PAD is a side-effect of their diabetes.

Further pre-clinical studies are currently in progress with ReN009, focusing on diabetic models and utilising the newly-developed frozen formulation of the CTX cell line which will be used in future clinical trials.

The results of these further studies will be reported in early 2010.

In the meantime, ReNeuron has scheduled meetings within the next month with both the UK Medicines and Healthcare Regulatory Agency (MHRA) and the UK Gene Therapy Advisory Committee (GTAC) in order to discuss and agree certain aspects of the late pre-clinical development plan for the ReN009 therapy.

ReNeuron is also planning meeting with regulatory authorities in other territories, including the US, ahead of initial clinical trials expected to commence in 2011.

ReNeuron failed to win US FDA approval for ReN001 stem-cell line three times.

ReN001 stem-cell line has a large potential market if the product is one day approved, analysts said.

Stem cells are the building blocks of life and researchers around the world are studying them to see whether they can be used safely for incurable diseases.

Stem cells derived from embryos have the ability to become any of the 210-odd types of cells in the human body.

ReNeuron has also developed a range of stem cell lines for non-therapeutic applications – its ReNcell® products for use in academic and commercial research.

RenNeuron’s ReNcell CX and ReNcell VM neural cell lines are marketed worldwide under license by USA-based Millipore Corporation.