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                                                                     EXHIBIT 4.4

CONFIDENTIAL TREATMENT - EDITED COPY

                                OPTION AGREEMENT

                                                                October 26, 2000

UBS AG, London Branch
c/o UBS Warburg LLC
[****]
[****]

Dear Sirs:

        SciClone Pharmaceuticals, Inc. (the "Company") wishes to confirm its
arrangement with you (the "Purchaser") in connection with (a) the issuance to
you, in exchange for a payment of $420,000 in immediately available funds as of
the Closing Date (as defined herein) , of an option (the "Series A Option") to
purchase, on the terms set forth herein, zero coupon convertible notes in the
form attached hereto as Annex I (the "Series A Convertible Notes"), in an
aggregate principal amount of $2,956,522 and convertible initially into 191,903
fully paid and non-assessable shares (each a "Share") of the Company's Common
Stock, no par value (the "Common Stock"), subject to adjustment as set forth in
the Series A Convertible Notes, and (b) the issuance from time to time between
the date hereof and December 15, 2000 (or such later date as you and we agree),
in exchange for payments in amounts to be agreed between you and us in writing
(such subsequent written agreements to be attached hereto and become a part
hereof), of options to purchase, on the terms set forth herein, additional
convertible notes, issuable in series, having such principal amounts, with such
series designation and convertible initially into such number of Shares as
agreed between us and set forth in such subsequent written agreements, but in
all other respects having the terms set forth in the form attached hereto as
Annex I (and with the applicable series designation, principal amount and
Conversion Rate inserted therein). The Series A Option and all other Options
which you purchase hereunder are collectively referred to as the "Options". The
Series A Convertible Notes and all other series of convertible notes the subject
of Options which you purchase hereunder are collectively referred to as the
"Convertible Notes."

        Simultaneously with the execution and delivery of this Agreement, you
and the Company have entered into a Registration Rights Agreement, dated as of
the date hereof (the "Registration Rights Agreement"), pursuant to which the
Company has agreed to register the Convertible Notes and the Shares under
certain circumstances. All capitalized terms not defined herein shall have the
meaning ascribed in the form of Convertible Notes.

        1. AGREEMENT TO ISSUE AND ACCEPT.

               (a) On the basis of the representations and warranties and
subject to the terms and conditions set forth herein, the Company agrees to
issue to you, and you agree to purchase from the Company, the Series A Option,
in consideration of which you agree to make a payment in the amount of $420,000
to the Company, as of the Closing Date, by wire transfer to the


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CONFIDENTIAL TREATMENT - EDITED COPY

Company's account [****]. The closing of the issuance and acceptance of the
Series A Option shall take place on November 2, 2000 (the "Closing Date").

               (b) Any subsequent issuance of Options will be similarly effected
on the basis of the representations and warranties and subject to the terms and
conditions set forth herein, in consideration of your agreement to make the
scheduled payments therefor, as set forth in writing as agreed between us. The
closing of the issuance and acceptance of each Option shall take place on such
date and time as you and the Company agree, at which time the Company shall
deliver to you a signed copy of the applicable terms, which shall thereupon be
attached to and become part of this Agreement.

               (c) The Company agrees that you may make a one-time election, on
or prior to December 31, 2000, to exchange Options of any two or more series for
Options of a single series, to purchase convertible notes having a Conversion
Rate equal to the weighted average of the Conversion Rates of the convertible
notes underlying the Options surrendered for exchange, but in all other respects
having the terms set forth in Annex I.

        2. EXERCISE OF CALL OPTION.

               (a) The Purchaser may exercise any Options issued hereunder at
any time on or prior to November 2, 2005, by delivering a written notice to the
Company (a "Purchaser's Call Option Notice") requiring the Company to issue and
sell (in which event the Purchaser shall purchase) Convertible Notes covered by
such Option having the principal amount specified in such notice (but not less
than $1,000,000 nor in excess of the maximum amount covered by such Option as
specified in the applicable terms) and the Conversion Rate specified in the
applicable terms but having the maturity date and in all other respects having
the terms set forth in the form attached hereto as Annex I (and with the
applicable series designation, principal amount and Conversion Rate inserted
therein), at a purchase price of 100% of the principal amount thereof.

               (b) Any issuance of Convertible Notes will be effected on the
basis of the representations and warranties and subject to the terms and
conditions set forth herein, against payment of the above-specified purchase
price therefor. The closing of the issuance and acceptance of such Convertible
Notes against such payment shall take place on such date and time as may be
specified in the Purchaser's Call Option Notice but no earlier than three
Business Days and no later than twenty Business Days after the date of delivery
of the Purchaser's Call Option Notice, at which time the Company shall deliver
to the Purchaser such Convertible Notes in certificated form against delivery by
the Purchaser of a wire transfer of the purchase price to the Company's account
[****]. Upon the occurrence of any Change of Control, the Company shall take
appropriate action to ensure that the Purchaser shall have the right to exercise
the Options after the Change of Control.

               (c) Subject to the conditions set forth in this Section 2(c), the
Company, upon five business days' notice to the Purchaser, may elect, in lieu of
delivering Convertible Notes pursuant to this Section 2, to deliver the number
of shares of Common Stock determined pursuant to the following formula:


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CONFIDENTIAL TREATMENT - EDITED COPY

                  N = P  x   CR
                            ----
                            1000

            where N = the number of shares of Common Stock so deliverable,

                  P = the principal amount of the Convertible Notes in lieu of
                      which such shares of Common Stock are delivered; and

                 CR = the Conversion Rate of the Convertible Notes in lieu of
                      which such shares of Common Stock are delivered, as set
                      forth in the applicable terms.

               (d) The Company covenants and agrees with the Purchaser that:

                      (i) If any Convertible Notes or shares of Common Stock to
be issued in lieu thereof pursuant to this Section 2 require registration with
or approval of any governmental authority under any State law or any other
Federal law before such shares may be validly issued or delivered, such
registration shall have been completed, have become effective and such approval
shall have been obtained, in each case, at or prior to the time of issuance of
such Convertible Notes or shares;

                      (ii) The shares of Common Stock issuable upon conversion
of such Convertible Notes or so deliverable shall have been approved for
quotation in the Nasdaq National Market or listed on a national securities
exchange at or prior to the time of issuance of such Convertible Notes or
shares; and

                      (iii) All shares of Common Stock issuable upon conversion
of such Convertible Notes or so deliverable shall be issued out of the Company's
authorized but unissued Common Stock and will, upon issue, be duly and validly
issued and fully paid and non-assessable and free of any preemptive rights.

        Notwithstanding any other provision of this Security, the Company shall,
if the holder so elects, deliver any shares of Common Stock issuable pursuant to
this Section 2 to any third party designated in writing by the holder.

               (e) In addition to any other rights available to the Purchaser,
if the Company defaults in its obligation to deliver to the Purchaser the
Convertible Notes (or shares of Common Stock in lieu thereof) required to be
delivered to it pursuant to this Section 2, the Company shall pay the Purchaser,
upon the Purchaser's demand, as liquidated damages by cash or wire transfer in
immediately available funds to the account of the Purchaser, or as otherwise
directed by the Purchaser, an amount determined pursuant to the following
formula:

                                   [* * * *]


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CONFIDENTIAL TREATMENT - EDITED COPY

                                   [* * * *]

        3. REPRESENTATIONS AND WARRANTIES OF THE COMPANY. The Company hereby
makes the representations and warranties to you set forth on Annex II hereto.
The Company will promptly notify you if at any time prior to the completion of
the purchases of Convertible Notes pursuant to the Agreement, for any reason
such representations and warranties are no longer in all respects true and
correct.

        4. AGREEMENTS OF PURCHASER. You covenant and agree with the Company
that:

               (a) You will not offer, sell, assign, hypothecate or otherwise
transfer the Convertible Notes except (i) pursuant to an effective registration
statement under the Securities Act of 1933 (the "Act"), (ii) to a person you
reasonably believe to be an "accredited investor" within the meaning of Rule 501
under the Act, pursuant to an available exemption under the Act or (iii) in
offshore transactions within the meaning and meeting the requirements of Rule
903 under the Act.

               (b) You will not offer, sell, assign, hypothecate or otherwise
transfer any Shares issued upon conversion, repurchase or payment of the
Convertible Notes or pursuant to this Agreement except (i) pursuant to an
effective registration statement under the Act; (ii) to a person you reasonably
believe to be an "accredited investor" within the meaning of Rule 501 under the
Act, pursuant to an available exemption under the Act or (iii) in an offshore
transaction within the meaning and meeting the requirements of Rule 903 under
the Act.

               (c) You are an "accredited investor" within the meaning of Rule
501 under the Act.

        5. CONDITIONS. Your obligations under this Agreement in respect of each
Option shall be subject to the condition that all representations and warranties
and other statements of the Company herein are true and correct at and as of the
closing of the purchase and sale of such Option; the condition that the Company
shall have performed all of its obligations hereunder theretofore to be
performed in respect of such Option; and the following additional conditions:

               (a) Counsel for the Company specified in Annex III hereto shall
have furnished to you their written opinion, dated the date of such closing, in
form and substance reasonably satisfactory to you, to the effect set forth in
Annex III hereto.

               (b) On the date of such closing, the Company shall have furnished
to you such appropriate further information, certificates and documents as you
may reasonably request.

               (c) Since the respective dates as of which information is given
in the Exchange Act Reports (as defined in Annex II hereto) to and including the
date of such closing, there shall not have been any material adverse change in
the capital stock or long-term debt of the Company or any of its subsidiaries or
any material adverse change, or any development that


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CONFIDENTIAL TREATMENT - EDITED COPY

is known to the Company to involve a prospective material adverse change, in or
affecting the business, properties, financial position, shareholders' equity or
results of operations of the Company and its subsidiaries, otherwise than as set
forth or contemplated in the Exchange Act Reports.

               (d) Up to and including the date of such closing, there shall not
have occurred any of the following: (i) a suspension or material limitation in
trading in securities generally on the New York Stock Exchange or the Nasdaq
National Market; (ii) a suspension or material limitation in trading in the
Company's securities on the Nasdaq National Market; (iii) a general moratorium
on commercial banking activities declared by either Federal or New York State
authorities; or (iv) the outbreak or escalation of hostilities involving the
United States or the declaration by the United States of a national emergency or
wary, if the effect of any such event specified in this Clause (iv) in your
reasonable judgment makes it impracticable or inadvisable to proceed with the
purchase of the Option on the terms and in the manner contemplated in this
Agreement.

        6. MISCELLANEOUS.

               (a) This Agreement shall be binding upon, and inure solely to the
benefit of, you and the Company and the respective executors, administrators,
successors and assigns thereof, and no other person shall acquire or have any
right under or by virtue of this Agreement. No purchaser of any Option from you
shall be deemed a successor or assign by reason merely of such purchase.

               (b) Any notice or other communication required or permitted to be
given hereunder shall be deemed effectively given when made by telephone and
confirmed in writing by certified mail, facsimile or overnight courier service
addressed as follows (as applicable):

               If to the Company, to:

               SciClone Pharmaceuticals, Inc.
               901 Mariner's Island Blvd., #205
               San Mateo, California  94404

               Attention: [****]
               Telephone Number: [****]
               Facsimile Transmission Number: [****]

               with a copy to:

               Gray Cary Ware & Freidenrich
               400 Hamilton Avenue
               Palo Alto, California  94301


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CONFIDENTIAL TREATMENT - EDITED COPY

               Attention:  David A. Hubb
               Telephone Number: 650-833-2164
               Facsimile Transmission Number: 650-327-3699

               If to the Purchaser, to:

               UBS AG, London Branch
               c/o UBS Warburg LLC
               [****]
               [****]

               Attention: [****]
               Telephone Number: [****]
               Facsimile Transmission Number: [****]

               with copies of the written notice to:

               UBS Warburg LLC
               [****]
               [****]

               Attention: [****]
               Telephone Number: [****]
               Facsimile Transmission Number: [****]

               Attention: [****]
               Telephone Number: [****]
               Facsimile Transmission Number: [****]

or to such other address or number and to the attention of such other person as
either party may designate by written notice to the other party. Notice shall be
effective upon actual receipt.

        For so long as the Purchaser is a holder of a Convertible Note, notices
to the Purchaser required or permitted to be given in under the terms of such
Convertible Note shall be given in the manner provided in this Section.

               (c) THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

               (d) Time shall be of the essence in the performance of this
Agreement.


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CONFIDENTIAL TREATMENT - EDITED COPY

               (e) This Agreement may be executed by the parties hereto in any
number of counterparts, each of which shall be deemed to be an original, but all
such respective counterparts shall together constitute one and the same
instrument.

                               Very truly yours,

                               SciClone Pharmaceuticals, Inc.

                               By:
                                    --------------------------------------------
                                    Name:  Donald R. Sellers
                                    Title: President and Chief Executive Officer

Accepted as of the date hereof:

UBS AG, London Branch


By:
    --------------------------------
    Name:
    Title:


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