Neotrofin™

Neotrofin, otherwise known as Leteprinim potassium or AIT-082, is a compound which can cross the blood-brain barrier and seems to stimulate the genes which produce what are known as neurotrophic factors. These are large proteins which are involved in nerve growth and neural protection and regeneration.

Clinical trials of Neotrofin have been underway for some time in the treatment of Alzheimer's disease and the results are currently being analysed. Further trials programmes relating to stroke, spinal cord injury and early Parkinson's disease have commenced. The phase 2 study of Neotrofin in Parkinson's is being conducted at five US hospitals specializing in the treatment of Parkinson's disease and movement disorders. To date, twenty-eight patients have been enrolled in the study, which is expected to conclude by the year-end.

The neurotrophic factors are naturally present in the brain, but they are not normally there in sufficient concentrations to protect fully against the causes of neuron death in Parkinson's, nor to replace the damaged cells. Neotrofin appears to stimulate multiple genes to produce these factors in the higher concentrations required. The neuroprotective effect of Neotrofin is thought to be due to its stimulation of the production of Heme oxygenase 1, which has been shown to protect against oxidative stress, a key factor in neurodegeneration.

With the announcement that Neotrofin causes neural stem cell proliferation, hopes are raised that this will provide a non-controversial alternative to the use of embryonic stem cells. In one of the studies with mice an increase in the number of mature neurons was observed after six weeks, although not in a second study. It remains to be discovered, however, whether these cells can become dopaminergic and take up residence in the substantia nigra.

The trials will be looking out for any adverse side effects following the administration of this drug. None seems to have been reported yet. Since it is orally administered, it may be that stopping the treatment would also cause the genes producing the higher concentrations of neurotrophic factors to switch off again and so curtail any further adverse effects on the brain - unlike stem cell transplants which are essentially irreversible.