SciClone and Sigma-Tau Sign ZADAXIN Partnership For

Italy, Spain and Switzerland / SciClone Continues Discussions for Additional U.S./European Partnerships SAN MATEO, Calif. (ots-PRNewswire) - SciClone Pharmaceuticals (Nasdaq: SCLN) announced that it has entered into a strategic partnership with Italy-based Sigma-Tau S.p.A., one of the leading pharmaceutical companies in Southern Europe, for late stage development and commercialization of SciClone's lead product, ZADAXIN(R) thymosin alpha 1, an immune system enhancer for the treatment of hepatitis and cancer. In Italy, Sigma-Tau has licensed and is successfully marketing Glaxo Wellcome's interferon for the treatment of hepatitis and cancer. Under the terms of the deal, Sigma-Tau received semi-exclusive ZADAXIN development and marketing rights in Italy and Spain, and exclusive rights in Switzerland. The Sigma-Tau Group of companies made an up-front equity investment in SciClone at a premium to the market. ZADAXIN currently is approved in Italy as an influenza vaccine adjuvant. The envisaged therapeutic indications of ZADAXIN in Italy include hepatitis B, hepatitis C and cancer. Sigma Tau will be responsible for clinical development and submission of ZADAXIN marketing applications in Italy. "We look forward to adding ZADAXIN as an important new drug to our product portfolio," said Claudio Cavazza, President of Sigma- Tau. "Europe shares the growing concern worldwide about hepatitis and cancer. ZADAXIN is a proven immune enhancement drug around the world that fits well into our development programs." "Sigma-Tau is a strong partner for these important European markets," said Donald R. Sellers, SciClone's President and Chief Executive Officer. "This deal allows us to accelerate our revenue timetable in Italy, the fifth largest pharmaceutical market in the world, and expand registration activities into several European countries. Importantly, this partnership permits the essential flexibility required for additional partnering efforts." SciClone remains in discussions with potential partners for development and commercialization of ZADAXIN in the U.S. and Europe. ZADAXIN is approved for marketing in 13 countries, principally as a treatment for hepatitis B and hepatitis C: Argentina, Cambodia, the People's Republic of China, Italy, Kuwait, Mexico, Myanmar, Peru, Pakistan, the Philippines, Singapore, Venezuela and Vietnam. SciClone has filed for ZADAXIN marketing approval in 19 additional countries. Sigma-Tau is one of the leading pharmaceutical groups in Italy. Therapeutic areas on which the company's research and development are focused include oncological, neurological, cardiovascular, gastroenterological and immunological indications, among others. Sigma-Tau has operating subsidiaries in Spain, Switzerland, the Netherlands, France, Germany and the United States and maintains a presence in all of the world's major pharmaceutical markets through either licensees or representative offices. In 1998, Sigma-Tau produced consolidated revenues of approximately $450 million. Press releases and corporate information from Sigma-Tau are available on the Internet at www.sigma-tau.it. SciClone Pharmaceuticals is a global biopharmaceutical company that acquires, develops and commercializes specialist-oriented drugs for treating chronic and life-threatening diseases, such as hepatitis B, hepatitis C, cystic fibrosis, cancer and immune system disorders. Press releases and corporate information from SciClone Pharmaceuticals are available on the Internet at www.sciclone.com or by calling the Company's Investor Relations Department at 800/724-2566. SciClone's common stock is listed on the Nasdaq National Market(R) under the symbol SCLN. The information in this press release includes certain forward-looking statements concerning the Company's current expectations regarding future events, including prospective ZADAXIN partnering arrangements in the U.S. and Europe and future benefits to the Company and its shareholders from development and commercialization of ZADAXIN in Italy, Spain and Switzerland. Due to market factors and the nature of product development and the regulatory approval process, the forward-looking statements contained in this press release are subject to risks and uncertainties, including those reflected in the Company's filings with the Securities and Exchange Commission, particularly its Annual Report on Form 10-K for the year ended December 31, 1998. ots Original Text Service: SciClone Pharmaceuticals Internet: http://www.newsaktuell.de Contact: Shawn K. Singh, Senior Vice President of SciClone Pharmaceuticals, 650-358-1451 Company News On-Call: http://www.prnewswire.com/comp/775865.html or fax, 800- 758-5804, ext. 775865 Web site: http://www.sigma-tau.it Web site: http://www.sciclone.com Subscribers please note that material bearing the slug "PROTEXT" is not part of CTK's news service and is not to be published under the "CTK" slug. Protext is a commercial service providing distribution of press releases from clients, who are identified in the text of Protext reports and who bear full responsibility for their contents. PROTEXT