Landmark Study Demonstrates Potential for Nerve Regeneration Treatment of Stroke -- Inosine Treatment Stimulates Brain Rewiring and Improves Function in Animals Following Stroke. Study Published in the Proceedings of the National Academy of Sciences



Story Filed: Tuesday, June 25, 2002 9:01 AM EST

BOSTON, Jun 25, 2002 (BW HealthWire) -- A landmark study published in the June 25 print edition of the Proceedings of the National Academy of Sciences demonstrates that Inosine, a naturally occurring chemical, can induce axon (nerve fiber) growth within the brain and spinal cord, and thereby improve motor function after stroke in animal models.

In the study, Inosine was shown to stimulate nerve cells in undamaged parts of the brain to grow new connections into brain areas that had lost their normal connections as a result of a stroke; this "rewiring" partially compensated for the loss of the original connections, and resulted in significant improvement in several types of behavior compared to rats that did not receive Inosine.

"These findings are of both scientific and clinical interest," said Larry Benowitz, the Principal Investigator on the study. Dr. Benowitz is the head of the laboratory at Children's Hospital where much of the work was carried out, and an Associate Professor of Neurology at Harvard Medical School. "The study shows that Inosine induces a great deal of rewiring in the brain after stroke. This rewiring is apparently sufficient to promote substantial functional recovery. In terms of clinical implications, Inosine, which appears to have no apparent side effects in animals thus far, has potential as a novel nerve regeneration approach to treatment of stroke and other types of brain injuries."

It is estimated that 750,000 people suffer first or recurrent strokes every year in the U.S. Stroke occurs when the brain is deprived of its blood supply either by a blood clot blocking a blood vessel (ischemic stroke) or a blood vessel rupturing in the brain, leaking blood and damaging tissue (hemorrhagic stroke). The third leading cause of death in the U.S. after heart disease and cancer, stroke claims the lives of 160,000 Americans each year and costs $30 billion in medical and rehabilitation expenses and lost productivity. More than half a million Americans survive stroke each year, often with drastic losses that impact their quality of life and basic functioning. Current treatments after stroke are limited to methods to restore blood flow and prevent the damage from spreading; as yet, there are no clinically approved methods, however, to enhance wiring.

Boston Life Sciences, Inc (BLSI) is developing Inosine for the treatment of stroke and other CNS injuries. Marc Lanser, M.D., Chief Scientific Officer of BLSI stated "We are excited to be associated with this extremely important study of Inosine, which has the potential to be the first nerve regeneration approach to treatment of stroke. In a separate study (not included in this publication) we have found that Inosine is effective even when administered as much as 24 hours after stroke. This is an additional important potential advantage over other current therapies."


Study Results
Inosine dramatically improved performance on each measure used for this animal study:


- When held by the torso and lowered toward a table, rats
treated with Inosine after a stroke showed greater ability to
place their paws on the table than untreated rats. After 19
days, treated rats had nearly normal paw-placing ability,
whereas untreated rats remained 50% below normal.
- In a separate experiment, animals were trained to reach
through the bars of a cage to grasp food pellets placed just
outside. By the 4th week of the study, with their unaffected
paw restrained, half of the Inosine-treated rats used their
stroke-affected paws to reach for food, compared to none of
the untreated rats with strokes. Moreover, when
Inosine-treated rats were allowed to reach with either paw,
20% continued to use the paw affected by stroke. In
comparison, very few untreated rats attempted to reach for
food using the affected paw. Of those who did try, none
succeeded in getting food and all attempts eventually stopped.
- Treatment with Inosine also helped improve rats' swimming
function after a stroke. Normally, rats unaffected by stroke
swim using only their hind limbs, holding their forelimbs
motionless under the chin. After a stroke, rats were no longer
able to hold their forelimbs motionless. However, by week 8,
those that received Inosine showed significantly greater
ability to regain control of their forelimbs while swimming.
Results of anatomical studies correlated with functional results. Typically, after a stroke on one side of the brain, nerve cells in unaffected areas, including those on the undamaged side of the brain, show a small amount of compensatory growth. Inosine increases the capacity of nerve cells to make new connections to those brain areas that have lost their normal inputs because of a stroke. The Inosine-stimulated increases were 3 to 4 times higher than in the rats that did not receive Inosine after stroke.

"Stroke has been a poorly understood and inadequately treated area of medicine," said Dr. Lanser. "These data offer great hope that we may finally see a breakthrough in treatment that can repair the damage wreaked by stroke."


About Boston Life Sciences, Inc.
Boston Life Sciences, Inc. is a biotechnology company developing novel diagnostics and therapeutics for Parkinson's Disease (PD) and Attention Deficit Hyperactivity Disorder (ADHD) as well as treatments for cancer, autoimmune disease, and central nervous system disorders. BLSI's products in development include: Altropane, a radio imaging agent for the diagnosis of PD and ADHD; Troponin I, a naturally-occurring anti-angiogenesis factor for the treatment of solid tumors; AF-1 and Inosine, nerve growth factors for the treatment of stroke, spinal cord and optic nerve injury; novel therapeutics for the treatment of PD and ADHD; and transcription factors that may control the expression of molecules associated with autoimmune disease and allergies. Since 1992, BLSI has raised more than $65 million to fund its research programs, which are primarily conducted at Harvard Medical School and its affiliated medical centers.

Statements made in this press release other than statements of historical fact may represent forward-looking statements. Such statements include, with limitation, statements regarding expectations or beliefs as to future results or events, such as the expected timing and results of clinical trials, discussions with regulatory agencies, schedules of IND, NDA and all other regulatory submissions, the timing of product introductions, the possible approval of products, and the market size and possible advantages of the Company's products. All such forward-looking statement involves substantial risks and uncertainties, and actual results may vary materially from these statements. Factors that may affect future results include: the availability and adequacy of financial resources, the ability to obtain intellectual property protection, delays in the regulatory or development processes, results of scientific data from clinical trials, the outcome of discussions with potential partners, regulatory decisions, market acceptance of the Company's products, and other possible risks and uncertainties that have been noted in reports filed by the Company with the Securities and Exchange commission, including the Company's Annual Report on Form 10-K.


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