FINANCIAL RELEASES - FIRST QUARTER 1998

AUTOIMMUNE INC. INITIATES COLLORAL® PHASE III TRIAL AND REPORTS FIRST QUARTER 1998 RESULTS

-- Preliminary Results of a Phase II Trial of Oral Insulin to be Presented at ADA in June --

Lexington, Massachusetts, May 5, 1998 -- AutoImmune Inc. (Nasdaq: AIMM) today announced that patient enrollment is well underway for the Colloral® Phase III trial for rheumatoid arthritis. The double-blind pivotal trial will enter a minimum of 800 patients at 36 participating U.S. centers. The study design compares a once a day 60 microgram oral dose of Colloral to placebo by traditional measures at the end of a six-month treatment period.

"The start of this pivotal trial marks a significant milestone for Colloral," said Robert C. Bishop, President and Chief Executive Officer of AutoImmune. "We have carefully designed the study based on a comprehensive analysis of data from the more than 1,200 patients who participated in our Phase II trials. We have seen rapid enrollment since the initiation of the trial in March and expect to complete the study in mid-1999."

Interim results for a U.S. Phase II trial for AI-401, AutoImmune's oral tolerance product for diabetes, will be presented at a poster session at the 1998 American Diabetes Association (ADA) Meeting in Chicago, June 13-16. The trial evaluates the feasibility of oral insulin therapy as a means to delay beta cell destruction in the pancreas, and thus preserve endogenous insulin secretion in newly diagnosed Type 1 diabetes patients. This study is one of four trials currently underway using AI-401, an oral formulation of recombinant human insulin. Eli Lilly and Company is AutoImmune's worldwide partner in autoimmune (Type 1) diabetes.

The Company also noted that its tenth and eleventh U.S. patents relating to oral tolerance technology were recently issued. Both patents are directed to the area of rheumatoid arthritis.

AutoImmune reported a net loss of $2.8 million, or $0.17 per share, for the quarter ended March 31, 1998, compared with a net loss of $7.6 million, or $0.47 per share, for the same quarter one year earlier. Research and development expenses decreased to $2.9 million for the quarter ended March 31, 1998, from $7.5 million in the comparable 1997 period, reflecting reduced research and clinical trial activity levels. As of March 31, 1998, the Company reported $27.5 million in cash and marketable securities.

AutoImmune is a biopharmaceutical company developing a new class of drug therapy for the treatment of cell-mediated inflammatory conditions. With highly focused human and capital resources, the Company has advanced several product candidates, all based on the principle of oral tolerance, into human clinical testing.

This release contains forward-looking statements which involve risks and uncertainties. The Company's actual results may differ significantly from results discussed in the forward-looking statements due to a number of important factors, including, but not limited to, the developmental stage of the Company's products and uncertainties of clinical trial results; the Company's capital requirements, history of operating losses and lack of product revenue, its limited manufacturing and marketing experience, and the risks of technological change and competition. These factors are more fully discussed in the Company's most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission.