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                                                                    EXHIBIT 10.5

                         COMMON STOCK PURCHASE AGREEMENT

        THIS COMMON STOCK PURCHASE AGREEMENT ("Agreement") is dated as of March
3, 2000 between SciClone Pharmaceuticals, Inc., a California corporation (the
"Company") and Sigma-Tau Finance S.A., a Luxembourg corporation having offices
at 13, bd du Prince Henri L-1724, Luxembourg (the "Investor").

                              W I T N E S S E T H:

        WHEREAS, the Company desires to sell and issue to the Investor, and the
Investor wishes to purchase from the Company, shares of the Company's Common
Stock, no par value, (the "Shares) with the number of Shares determined as
provided in Section 1.2 on the terms and conditions set forth herein

        NOW, THEREFORE, in consideration of the foregoing premises and the
covenants contained herein and other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the parties hereto
agree as follows:



                                    ARTICLE I

                        PURCHASE AND SALE OF COMMON STOCK

        Section 1.1 Purchase and Sale of Common Stock. Upon the following terms
and conditions, the Company shall issue and sell the Shares to the Investor, and
the Investor shall purchase the Shares from Company.

        Section 1.2 Purchase Price. The purchase price for the Shares shall be
three million dollars ($3,000,000) ("the Aggregate Purchase Price"). The number
of Shares shall be equal to the Aggregate Purchase Price divided by the Per
Share Price. For purposes of this Agreement, the "Per Share Price" shall be
$15.146, which price is equal to the average of the closing sale prices of the
Company's Common Stock as quoted on the Nasdaq Stock Market for the three (3)
trading days ending one (1) day prior to the Closing (as defined below) date.

        Section 1.3 The Closing. The closing of the purchase and sale of the
Shares shall take place immediately upon execution of this Agreement by both
parties (the "Closing"). Ten (10) days after the Closing (upon determination of
the number of Shares), the Company shall (i) deliver to Investor certificates,
with the number of and denomination of such certificates as reasonably requested
by Investor, representing the Shares purchased hereunder by Investor registered
in the name of Investor or its nominee or (ii) shall deposit such Common Shares
into accounts designated by Investor; at the Closing, Investor shall deliver to
the Company the Purchase Price for the Shares purchased by Investor hereunder by
wire transfer in immediately available funds to an account designated in writing
by the Company.



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                                   ARTICLE II

                         REPRESENTATIONS AND WARRANTIES

        Section 2.1 Representations and Warranties of the Company. The Company
hereby makes the following representations and warranties to Investor as of the
date hereof:

            (a) Organization and Qualification; Material Adverse Effect. The
Company is a corporation duly incorporated and existing in good standing under
the laws of the State of California.

            (b) Authorization; Enforcement. (i) the Company has the requisite
corporate power and authority to enter into and perform this Agreement and to
issue the Shares in accordance with the terms hereof, (ii) the execution and
delivery of this Agreement by the Company and the consummation by it of the
transactions contemplated hereby and thereby, including the issuance of the
Shares, have been duly authorized by all necessary corporate action, and no
further consent or authorization of the Company or its board of directors (the
"Board") or shareholders is required, and (iii) this Agreement constitutes a
valid and binding obligation of the Company, enforceable against the Company in
accordance with its terms, except as such enforceability may be limited by
applicable bankruptcy, insolvency, reorganization, moratorium, liquidation or
similar laws relating to, or affecting generally the enforcement of creditors'
rights and remedies or by other equitable principles of general application.

            (c) Issuance of the Shares. The Shares are duly authorized and
reserved for issuance and will, when issued, be validly issued, fully paid and
non-assessable, free and clear of any and all liens, claims and encumbrances,
other than securities law restrictive legends until the Shares can be sold
without being registered with the United States Securities and Exchange
Commission (the "SEC").

            (d) No Conflicts. The execution, delivery and performance of this
Agreement and the consummation by the Company of the transactions contemplated
hereby and thereby do not and will not (i) result in a violation of the
Company's organizational documents, or (ii) conflict with any agreement,
indenture or instrument to which the Company is a party, or (iii) result in a
violation of any law, rule, regulation, or any order, judgment or decree of any
court or governmental agency applicable to the Company. The Company is not
required to obtain any consent or authorization of any U.S. governmental agency
in order for it to perform its obligations under this Agreement.

        Section 2.2 Representations and Warranties of the Investor. Investor
hereby makes the following representations and warranties to the Company as of
the date hereof and on and as of the Closing Date:

            (a) Authorization; Enforcement. (i) Investor has the requisite power
and authority to enter into and perform this Agreement and to purchase the
Shares being sold hereunder, (ii) the execution and delivery of this Agreement
by Investor and the consummation by it of the transactions contemplated hereby
and thereby have been duly authorized by all necessary action,


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and (iii) this Agreement constitutes a valid and binding obligation of Investor,
enforceable against Investor in accordance with its terms, except as such
enforceability may be limited by applicable bankruptcy, insolvency,
reorganization, moratorium, liquidation or similar laws relating to, or
affecting generally the enforcement of creditors' rights and remedies or by
other equitable principles of general application.

            (b) No Conflicts. The execution, delivery and performance of this
Agreement and the consummation by Investor of the transactions contemplated
hereby and thereby do not and will not (i) result in a violation of Investor's
organizational documents, or (ii) conflict with any agreement, indenture or
instrument to which Investor is a party, or (iii) result in a violation of any
law, rule, regulation, or any order, judgment or decree of any court or
governmental agency applicable to Investor. Investor is not required to obtain
any consent or authorization of any governmental agency in order for it to
perform its obligations under this Agreement.

            (c) Investment Representation. Investor is purchasing the Shares for
its own account and not with a view to distribution in violation of any
applicable securities laws. Investor has no present intention to sell the Shares
and Investor has no present arrangement (whether or not legally binding) to sell
the Shares to or through any person or entity.

                                   ARTICLE III

                            SHARE RESALE RESTRICTIONS

        Section 3.1 Share Resale Restrictions.

            (a) Restricted Securities. Investor will not make any sale, transfer
or other disposition of the Shares during the year following the date of this
Agreement, and thereafter only if (i) such sale, transfer or other disposition
is within the limitations of and in compliance with Rule 144 promulgated by the
SEC under the Securities Act, (ii) some other exemption from registration under
the Securities Act is available with respect to any such proposed sale, transfer
or other disposition of the Shares, or (iii) such distribution of Shares has
been registered under the Securities Act.

            (b) Legend. Each certificate representing the Shares shall be
stamped or otherwise imprinted with a legend substantially in the following
form:

        THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
1933 OR ANY STATE SECURITIES LAWS. THEY MAY NOT BE SOLD, PLEDGED, TRANSFERRED OR
OTHERWISE DISPOSED OF EXCEPT IN ACCORDANCE WITH THE REQUIREMENTS OF THE
SECURITIES ACT OF 1933, AS AMENDED AND THE OTHER CONDITIONS SPECIFIED IN THE
COMMON STOCK PURCHASE AGREEMENT DATED AS OF MARCH 3, 2000 BETWEEN THE HOLDER OF
THIS CERTIFICATE AND SCICLONE PHARMACEUTICALS, INC.

        The Company agrees to reissue certificates representing the Shares
without the legend set forth above at such time as (i) the Shares have been held
for a period of two (2) years and (ii) the


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holder thereof is permitted to dispose of such Shares pursuant to Rule 144(k)
under the Securities Act, or such Shares are sold to a purchaser or purchasers
who (in the opinion of counsel to the seller or such purchaser(s), in form and
substance reasonably satisfactory to the Company and its counsel) are able to
dispose of such shares publicly without registration under the Securities Act.

            (c) Current Public Information. With a view to making available the
benefits of certain rules and regulations of the SEC which may at any time
permit the sale of the Shares to the public without registration, Company agrees
to use its reasonable best efforts to:

                (i) Make and keep current public information available, as those
terms are understood and defined in Rule 144 under the Securities Act, for at
least the next two (2) years after the date of this Agreement;

                (ii) File with the SEC in a timely manner all reports and other
documents required of Company under the Securities Act and the Securities
Exchange Act of 1934, as amended (the "Exchange Act"); and

                (iii) Furnish to Investor forthwith upon request a written
statement by Company as to its compliance with the conditions set forth in Rule
144 c), and the reporting requirements of the Securities Act and the Exchange
Act, a copy of the most recent annual or quarterly report of Company, and such
other reports and documents of Company and other information in the possession
of or reasonably obtainable by Company as Investor may reasonably request in
availing itself of any rule or regulation of the SEC allowing Investor to sell
any of the Shares without registration.

                                   ARTICLE IV

                                  MISCELLANEOUS

        Section 4.1 Specific Enforcement; Consent to Jurisdiction.

            (a) The Company and Investor acknowledge and agree that irreparable
damage would occur in the event that any of the provisions of this Agreement
were not performed in accordance with their specific terms or were otherwise
breached. It is accordingly agreed that the parties shall be entitled to an
injunction or injunctions to prevent or cure breaches of the provisions of this
Agreement and to enforce specifically the terms and provisions hereof, this
being in addition to any other remedy to which any of them may be entitled by
law or equity.

            (b) The Company and Investor (i) hereby irrevocably submit to the
exclusive jurisdiction of the United States District Court, the California State
courts and other courts of the United States sitting in San Mateo County,
California for the purposes of any suit, action or proceeding arising out of or
relating to this Agreement and (ii) hereby waive, and agree not to assert in any
such suit action or proceeding, any claim that it is not personally subject to
the jurisdiction of such court, that the suit, action or proceeding is brought
in an inconvenient forum or that the venue of the suit, action or proceeding is
improper. The Company and Investor consent to process being served in any such
suit, action or proceeding by mailing a copy thereof



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to such party at the address in effect for notices to it under this Agreement
and agrees that such service shall constitute good and sufficient service of
process and notice thereof. Nothing in this paragraph shall affect or limit any
right to serve process in any other manner permitted by law.

        Section 4.2 Entire Agreement; Amendment. This Agreement, contains the
entire understanding of the parties with respect to the matters covered hereby
and, except as specifically set forth herein, neither the Company nor Investor
make any representation, warranty, covenant or undertaking with respect to such
matters. No provision of this Agreement may be waived or amended other than by a
written instrument signed by the party against whom enforcement of any such
amendment or waiver is sought.

        Section 4.3 Notices. Any notice or other communication required or
permitted to be given hereunder shall be in writing and shall be effective upon
actual receipt of such notice. The addresses for such communications shall be:

        to the Company:             SciClone Pharmaceuticals, Inc.
                                    901 Mariners Island Boulevard
                                    San Mateo, California  94404
                                    Fax:  (650) 358-3469
                                    Attn:  Shawn K. Singh

        to Investor, then to the address set forth under Investor's name on the
signature page of this Agreement.

Any party hereto may from time to time change its address for notices by giving
at least ten (10) days written notice of such changed address to the other
parties hereto.

        Section 4.4 Indemnity. Each party shall indemnify each other party
against any loss, cost or damages (including reasonable attorney's fees but
excluding consequential damages) incurred as a result of such parties' breach of
any representation, warranty, covenant or agreement in this Agreement.

        Section 4.5 Waivers. No waiver by any party of any default with respect
to any provision, condition or requirement of this Agreement shall be deemed to
be a continuing waiver in the future or a waiver of any other provision,
condition or requirement hereof, nor shall any delay or omission of any party to
exercise any right hereunder in any manner impair the exercise of any such right
accruing to it thereafter.

        Section 4.6 Headings. The headings herein are for convenience only, do
not constitute a part of this Agreement and shall not be deemed to limit or
affect any of the provisions hereof.

        Section 4.7 Successors and Assigns. Except as otherwise provided herein,
this Agreement shall be binding upon and inure to the benefit of the parties and
their successors and permitted assigns. The parties hereto may amend this
Agreement without notice to or the consent of any third party. The Company and
Investor may not assign this Agreement or any rights or obligations hereunder
without the prior written consent of the other party (which



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consent shall not be unreasonably withheld), except that the Company may assign
this Agreement in connection with a merger, acquisition or the sale of all or
substantially all of its assets provided that the Company is not released from
any of its obligations hereunder, such assignee assumes all obligations of the
Company hereunder, and appropriate adjustment of the provisions contained in
this Agreement is made, in form and substance satisfactory to Investor, to place
Investor in the same position as it would have been but for such assignment; and
except further that upon 30 days prior written notice to the Company, the
Investor may assign at any time this Agreement or any rights or obligations
hereunder to any of Investor's Affiliate's without the prior written consent of
the Company. Affiliate means any person, firm or corporation which, directly or
indirectly, through one or more intermediaries, controls, is controlled by, or
is under common control with, a party. "Control" means the legal or beneficial
ownership of 50% or more of the voting or equity interests or the power or right
to direct the management and affairs of the business (including acting as the
general partner of a limited partnership).

        Section 4.8 No Third Party Beneficiaries. This Agreement is intended for
the benefit of the parties hereto and their respective permitted successors and
assigns and is not for the benefit of, nor may any provision hereof be enforced
by, any other person.

        Section 4.9 Governing Law. This Agreement shall be governed by and
construed and enforced in accordance with the internal laws of the State of
California without regard to such state's principles of conflict of laws.

        Section 4.10 Survival. The representations and warranties and the
agreements and covenants of the Company and the Investor contained herein shall
survive the Closing.

        Section 4.11 Execution. This Agreement may be executed in two or more
counterparts, all of which shall be considered one and the same agreement, it
being understood that all parties need not sign the same counterpart.

        Section 4.12 Attorney's Fees. Investor shall be entitled to recover from
the Company the reasonable attorney's fees and expenses incurred by Investor in
connection with enforcement by Investor of any obligation of the Company under
this Agreement.

        Section 4.13 Counterparts. This Agreement may be signed in multiple
counterparts. Signatures may be transmitted by facsimile telecopier.


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        IN WITNESS WHEREOF, the parties hereto have caused this Common Stock
Purchase Agreement to be duly executed as of the date first above written.


                                         COMPANY:

                                         SCICLONE PHARMACEUTICALS, INC.


                                         By: _________________________________
                                         Printed Name:
                                         Title:

                                         INVESTOR:

                                         SIGMA-TAU FINANCE S.A.


                                         By: _________________________________

                                         Printed Name:________________________

                                         Title: ______________________________



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