Citicoline Stroke Trial Does Not Achieve Primary Clinical Endpoint.

Business Editors & Health/Medical Writers

LEXINGTON, Mass.--(BW HealthWire)--Jan. 10, 2000

Interneuron Pharmaceuticals, Inc. (NASDAQ: IPIC) today announced that a preliminary analysis of an 899-patient Phase 3 clinical trial with citicoline failed to meet its primary endpoint, a measure of improvement in neurological function among patients suffering from moderate to severe ischemic stroke. The double blind, placebo controlled trial, known as ECCO 2000 (Effects of Citicoline on Clinical Outcome - 2000 mg), was conducted at more than 170 hospitals in the U.S. and Canada.

The pre-specified, primary outcome measurement of the trial was the comparison of the percentages of patients treated with citicoline or placebo who achieved at least a 7-point improvement on NIHSS (National Institutes of Health Stroke Scale) scores from enrollment through the combined 12-week treatment and follow-up period. Secondary outcomes included additional comparisons of neurological function and infarct volume measurements among citicoline and placebo patients at the end of the study.

Although improvement in the primary outcome measurement was not achieved, certain secondary endpoints were positive. At the end of the 12-week trial period, a statistically significantly higher proportion of citicoline-treated patients achieved complete or near-complete recovery of neurological function compared to placebo-treated patients, as measured by the Rankin Scale. Likewise, at the same time point, NIHSS scores indicated a strongly positive trend in the number of citicoline-treated patients who achieved full neurological recovery. Although not statistically significant, a higher percentage of citicoline-treated patients achieved reduction in the size of their cerebral infarct compared to placebo-treated patients. In addition, preliminary review of findings from this study indicates that there were no significant adverse safety issues associated with citicoline.

"We are certainly disappointed with these results," said Glenn L. Cooper, M.D., president and chief executive officer of Interneuron. "This was a well-designed trial that incorporated everything we and others have learned over the past several years in the field of stroke study design. The findings underscore the historical difficulty in predicting the outcome of stroke trials and the actual clinical impact of drugs intended to treat this disease. For example, the placebo response rate for the primary outcome variable in this study exceeded 50 percent, higher than what we have seen in our previous trials involving several hundred patients. We hope that the knowledge gleaned from a full analysis of ECCO 2000 will add value to the overall database of clinical trials in stroke.

"Decisions regarding any future U.S. development of citicoline will be made in consultation with Takeda Chemical Industries, to whom Interneuron recently licensed rights for citicoline in the U.S. and Canada," said Dr. Cooper.

Full results of ECCO 2000 will be presented at the 25th International Stroke Conference, sponsored by the American Stroke Association and scheduled from February 10-12, 2000.

In 1993, Interneuron licensed exclusive marketing and manufacturing rights for citicoline in the U.S. and Canada from Ferrer Internacional, S.A., a leading European pharmaceutical company. Interneuron licensed to Takeda Chemical Industries Ltd. exclusive U.S. and Canadian commercialization rights to citicoline in December 1999.

Interneuron Pharmaceuticals is engaged in the development and commercialization of a portfolio of products and product candidates for central nervous system and other disorders, including multiple compounds in late-stage clinical development.

Except for the descriptions of historical facts contained herein, this press release contains forward-looking statements that involve risks and uncertainties that could cause the Company's actual results and financial condition to differ materially from those anticipated by the forward looking statements. These risks and uncertainties are set forth in the Company's filings under the Securities Act of 1933 and the Securities Exchange Act of 1934 under "Risk Factors" and elsewhere, and include, but are not limited to, risks relating to the Redux-related litigation, uncertainties relating to clinical trials and regulatory approvals; need for additional funds and corporate partners; history of operating losses and expectation of future losses; product liability; dependence on third parties for manufacturing and marketing; the early stage of products under development; government regulation, patent risks and competition.