Boston Life Sciences' Stroke Recovery Therapeutic Demonstrates Further Favorable Results in Toxicity Tests.

Business Editors and Health/Medical Writers

BOSTON--(BW HealthWire)--March 22, 2002

Completed toxicity tests reveal no inosine-stimulated unwanted

abnormal axon growth in rats.

Boston Life Sciences, Inc. (NASDAQ: BLSI) announced that Inosine, the Company's pre-clinical product candidate designed to promote central nervous system (CNS) nerve regeneration, appears not to cause random, uncontrolled axon regeneration in normal rats. This conclusion is based on the results of a recently-completed 28-day toxicity test in rats. Prior pre-clinical studies have demonstrated significant useful axon formation in rats administered Inosine following stroke.

The 28-day toxicity test was performed in rats to determine whether there were any adverse general (non-CNS) or CNS-specific dose-limiting toxicity associated with continuous CNS administration of Inosine. The route of administration was chosen to be identical to that anticipated for use in the Company's planned Phase I/II clinical studies in stroke patients. The maximal dosage used in the toxicity test was up to 25-fold the established effective dose in rats. A detailed microscopic examination and analysis of brain tissue was performed to detect any random unwanted new axon growth in the brains of treated rats compared to the brains of untreated control rats. No increase in random, inappropriate axon growth or proteins associated with such growth was detected. However, as shown in prior pre-clinical studies, rats with experimentally-induced strokes when treated with Inosine demonstrate significant, useful, new, functionally relevant axon formation as compared to rats treated with saline alone. Inosine-induced new axon formation has been shown in pre-clinical studies to correlate with, and thus, apparently, to promote meaningful functional improvement after stroke in Inosine-treated rats compared to the control rats.

"Based on the accumulated efficacy data in our pre-clinical experimental stroke trials, we have been excited for some time about Inosine's potential to improve function after stroke by stimulating the growth of "normal" compensatory functional axons within the CNS," stated Dr. Marc Lanser, Chief Scientific Officer of BLSI. "Before filing our Investigational New Drug Application (IND) with the Food and Drug Administration (FDA) and seeking FDA approval to proceed with our clinical program, we wanted to prove to our satisfaction that Inosine would not also promote disruptive and non-regulated axon growth, which could potentially cause bizarre changes in behavior, personality or normal function. An important predictor in this regard would be whether Inosine would induce any axon regeneration when given to normal rats. The answer appears to be no," added Dr. Lanser.

BLSI is 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(TM) and FLUORATEC(TM) radioimaging agents 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 acute and chronic CNS disorders; novel therapies for the treatment of PD and ADHD; and transcription factors that may control the expression of molecules associated with autoimmune disease and allergies.

Statements made in this press release other than statements of historical fact represent forward-looking statements. Such statements include, without 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 statements involve 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. The Company does not intend to update any of the forward-looking statements after the date of this press release or to conform these statements to actual future events.