``Buy'' Rating for Questcor Pharmaceuticals Issued by Aurora Capital.

Business Editors

HAYWARD, Calif.--(BUSINESS WIRE)--June 29, 2000

Questcor Pharmaceuticals, Inc. (AMEX:QSC) announced today that Aurora Capital LLC analyst Ronald Urvater reiterated a BUY rating on the company late last week. The report cites significant reduction of the company's burn rate, a new potentially viable application for one drug candidate, and pivotal clinical trial results for two other drug candidates.

The report highlighted the steady progress Questcor, under the management of Charles J. Casamento, has made within just six months since the merger between RiboGene, Inc. and Cypros Pharmaceuticals Corp., in reducing the company's burn rate from $18 million to an estimated $11 million for fiscal year 2000. The report cites significant cost savings through the elimination of redundant staff positions after the merger and elimination of certain long-term leases. In addition, the company licensed its anti-bacterial drug discovery program Pathogen Specific Translation Mechanism to Dainippon Pharmaceutical Co., Ltd. of Japan in exchange for $2 million plus royalty payments. And finally, Questcor ceased a sickle cell anemia trial for the drug candidate Cordox(TM) and refocused that drug for a potentially lucrative use as a blood preservative. Ending that trial will result in savings of $6 million.

Cordox(TM) is currently in phase II clinical trials as a cytoprotective agent targeted at major indications such as coronary artery bypass graft and prevention of immune rejection due to organ transplants. The BUY report focused on the company's identification of the new indication for Cordox(TM) as a blood preservative. Blood is normally preserved for 6 to 12 weeks and then must be destroyed because the whole blood cells can no longer be used for transfusion. Questcor believes that Cordox(TM) may extend blood's storage life for an additional 6 to 8 weeks, which would represent significant cost savings to blood centers as well as extend the nation's blood supply. Trials are currently underway at Hoxworth at the University of Cincinnati. Pending eventual FDA approval, Cordox(TM) could reach market by 2003.

In addition, the BUY report cited two other near-term products that may be approved by the FDA and on the market by 2003. For the first, patient enrollment and treatment were completed in May for Emitasol(R), a drug designed to treat diabetic gastroparesis. Assuming Emitasol(R) is approved for this purpose, the report states that the potential royalty stream beginning in 2003 could start at $6 million per year with a 25 to 30% growth rate. In addition, phase III trials for controlling emesis due to cancer chemotherapy yielded extremely positive results. For the second drug candidate, phase II trials for Ceresine(TM), designed to treat congenital lactic acidosis, a lethal condition that affects infants, also yielded positive results, for which reports are currently being written. The report estimates a potential market for this use of the drug of $100 million assuming 80% market share. There currently is no therapy available for this ailment.

Finally, the BUY report comments on Questcor's currently approved products -- Ethamolin(TM), Sildaflo(TM), and Neoflo(TM) -- and their revenue generating progress. The report states that they may reach combined revenues of $30 million to $40 million over the next 3 to 4 years. The report also cites as positive factors the recent strengthening of management by adding a VP of Clinical and Regulatory Affairs and a VP of Sales and Marketing.

Questcor Pharmaceuticals, Inc. is a fully integrated specialty pharmaceutical company whose focus is to serve the needs of the acute care and critical care hospital market. The Company's strategy includes the acquisition and marketing of hospital pharmaceutical products, the generation of revenue streams from these products and the continued funding of late stage, acute care and critical care pharmaceutical research and development programs. Questcor was created as a result of the merger, on November 17, 1999, between Cypros Pharmaceutical Corp. and RiboGene, Inc.

For more information on Questcor, please contact our Web site at www.questcor.com.

Note: Except for the historical information contained herein, this press release contains forward-looking statements that involve risks and uncertainties. Such statements are subject to certain factors, which may cause the Company's results to differ. Factors that may cause such differences include, but are not limited to, the Company's need for additional funding, uncertainties regarding the company's intellectual property and other research, development, marketing and regulatory risks, and, the ability of the Company to implement its strategy and acquire products and, if acquired, to market them successfully as well as the risks discussed in Questcor's transition report on Form 10-K for the fiscal year ended December 31, 1999 and the Risk Factor section of Cypros' Registration Statement on form S-4 (No. 333-87611), RiboGene's Annual Report on Form 10-K for the fiscal year ended December 31, 1998 and other documents filed with the Securities and Exchange Commission. The risk factors and other information contained in these documents should be considered in evaluating Questcor's prospects and future financial performance.