Zadaxin available in Mexico

August 2, 2000

SciClone Pharmaceuticals Launches Zadaxin® in Mexico

SAN MATEO, Calif., Aug. 2 /PRNewswire/ --

SciClone Pharmaceuticals (Nasdaq: SCLN) today announced that it has begun

marketing and distributing ZADAXIN®, its lead immunotherapy, in Mexico.

ZADAXIN is also approved for sale in other Latin American markets, including

Argentina, Venezuela and Peru.

ZADAXIN marketing and distribution in Latin America is managed for

SciClone by Craig Olson, a 19-year veteran of Schering-Plough Corporation's

Latin American business. Olson, who is based in Panama, was recently hired by

SciClone as Regional Managing Director, Latin America.

" Mexico represents our first North American product launch and a key to

the Latin American market as a whole, " said R. Sellers, SciClone's

President and Chief Executive Officer. " Introducing ZADAXIN into this market

will provide support for our continuing revenue growth and enable key

audiences in the U.S. to observe the safety and efficacy of ZADAXIN. "

ZADAXIN is approved for sale in 20 countries, principally for the

treatment of hepatitis B and hepatitis C and as a vaccine adjuvant for

patients with weakened immune systems.

SciClone plans to start a phase 3 ZADAXIN hepatitis C program in the U.S. by

the end of the year.

The U.S. program will be complemented by a phase 3 hepatitis C program in

Europe to be conducted by Sigma-Tau S.p.A., SciClone's partner. ZADAXIN is

in phase 2

development in the U.S. in combination with lamivudine for the treatment of

hepatitis B. SciClone plans to initiate U.S. phase 2 ZADAXIN clinical

programs in liver cancer and malignant melanoma by the end of the year. A

phase 3 ZADAXIN hepatitis B study is ongoing in Japan. ZADAXIN has been

administered to over 3,000 subjects in over 70 clinical trials covering a

broad range of diseases, and an estimated 7,000 patients commercially, with

virtually no serious drug related side effects or toxicities.

SciClone Pharmaceuticals is a global specialty pharmaceutical company that

develops and commercializes novel medicines for the treatment of a broad range

of the world's most serious diseases. The Company is currently targeting

malignant melanoma, liver cancer, hepatitis B, hepatitis C, HIV,

drug-resistant tuberculosis and cystic fibrosis. 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® 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 continuing ZADAXIN revenue growth, the commercial success of

ZADAXIN in Latin America, particularly in Mexico, and the ongoing and

prospective development and commercialization of ZADAXIN immunotherapy in the

U.S., Europe and Japan for cancer, hepatitis B and hepatitis C, the timing of

the start and potential for success of the Company's U.S. phase 2 studies for

cancer and its ZADAXIN phase 3 studies for hepatitis C in the U.S., and

Sigma-Tau's ZADAXIN phase 3 studies for hepatitis C in Europe. 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 the

Company's Annual Report on Form 10-K for the year ended December 31, 1999.

SOURCE SciClone Pharmaceuticals

-0- 08/02/2000

/CONTACT: Ruth Koh, Investor Relations of SciClone Pharmaceuticals,

650-358-3437; or Ian McConnell, Ph.D. of Noonan Russo Communications, Inc.,

415-677-4455, for SciClone Pharmaceuticals/

/Web site: http://www.sciclone.com/

(SCLN)