EXHIBIT 10.45

                                     FORM OF
                            STOCK PURCHASE AGREEMENT

         This STOCK PURCHASE AGREEMENT (this "AGREEMENT") is dated as of this
5th day of February, 2001 by and between La Jolla Pharmaceutical Company, a
Delaware corporation with its principal office at 6455 Nancy Ridge Drive, San
Diego, California (the "COMPANY"), and the several purchasers named in Exhibit A
attached hereto (each, a "PURCHASER" and collectively, the "PURCHASERS").

         WHEREAS, the Company desires to issue and sell to the Purchasers an
aggregate of up to 5,700,000 shares (the "SHARES") of the authorized but
unissued shares of common stock, $0.01 par value per share, of the Company (the
"COMMON STOCK"); and

         WHEREAS, the Purchasers, severally, wish to purchase the Shares on the
terms and subject to the conditions set forth in this Agreement.

         NOW THEREFORE, in consideration of the mutual agreements,
representations, warranties and covenants herein contained, the parties hereto
agree as follows:

         1.       Definitions. As used in this Agreement, the following terms
shall have the following respective meanings:

                  (a)      "Affiliate" of a party means any corporation or other
business entity controlled by, controlling or under common control with such
party. For this purpose "CONTROL" shall mean direct or indirect beneficial
ownership of fifty percent (50%) or more of the voting or income interest in
such corporation or other business entity.

                  (b)      "Closing Date" means the date of the Closing.

                  (c)      "Exchange Act" means the Securities Exchange Act of
1934, as amended, and all of the rules and regulations promulgated thereunder.

                  (d)      "Registration Rights Agreement" shall mean that
certain Registration Rights Agreement, dated as of the date hereof, among the
Company and the Purchasers.

                  (e)      "Majority Purchasers" shall mean Purchasers which, at
any given time, hold greater than fifty percent (50%) of the voting power of the
outstanding Shares.

                  (f)      "SEC" shall mean the Securities and Exchange
Commission.

                  (g)      "Securities Act" shall mean the Securities Act of
1933, as amended, and all of the rules and regulations promulgated thereunder.

         2.       Purchase and Sale of Shares.

                  2.1      Purchase and Sale. Subject to and upon the terms and
conditions set forth in this Agreement, the Company agrees to issue and sell to
each Purchaser, and each Purchaser, severally, hereby agrees to purchase from
the Company, at the Closing, the number of shares of Common Stock set forth
opposite the name of such Purchaser under the heading "Number of Shares to be
Purchased" on Exhibit A hereto, at a purchase price of $6.20 per share. The
total purchase price payable by each Purchaser for the number of shares of
Common Stock that such Purchaser is hereby agreeing to purchase is set forth
opposite the name of such Purchaser under the heading "Purchase Price" on
Exhibit A hereto. The aggregate purchase price payable by the Purchasers to the
Company for all of the Shares shall be $35,340,000.

                  2.2      Closing. The closing of the transactions contemplated
under this Agreement (the "CLOSING") shall take place at the offices of Gibson,
Dunn & Crutcher LLP in Irvine, California on February 7, 2001, or at such other
location, date and time as may be agreed upon between the Purchasers and the
Company. At the Closing, the Company shall deliver to each Purchaser a single
stock certificate, registered in the name of such Purchaser, representing the
number of shares of Common Stock



purchased by such Purchaser, against payment of the purchase price therefor by
wire transfer of immediately available funds to such account or accounts as the
Company shall designate in writing.

         3.       Representations and Warranties of the Company. The Company
hereby represents and warrants to each of the Purchasers as follows:

                  3.1      Incorporation. The Company is a corporation duly
organized, validly existing and in good standing under the laws of the State of
Delaware and is qualified to do business in each jurisdiction in which the
character of its properties or the nature of its business requires such
qualification, except where the failure to so qualify would not have a material
adverse effect upon the Company. The Company has all requisite corporate power
and authority to carry on its business as now conducted.

                  3.2      Capitalization. The authorized capital stock of the
Company consists of (i) 100,000,000 shares of Common Stock, of which 29,395,087
shares are outstanding as of January 30, 2001, and (ii) 8,000,000 shares of
preferred stock, of which no shares are outstanding on the date hereof. Except
as set forth in Schedule 3.2 hereto, there are no existing options, warrants,
calls, preemptive (or similar) rights, subscriptions or other rights,
agreements, arrangements or commitments of any character obligating the Company
to issue, transfer or sell, or cause to be issued, transferred or sold, any
shares of the capital stock of the Company or other equity interests in the
Company or any securities convertible into or exchangeable for such shares of
capital stock or other equity interests, and there are no outstanding
contractual obligations of the Company to repurchase, redeem or otherwise
acquire any shares of its capital stock or other equity interests.

                  3.3      Authorization. All corporate action on the part of
the Company, its officers, directors and stockholders necessary for the
authorization, execution, delivery and performance of this Agreement and the
Registration Rights Agreement and the consummation of the transactions
contemplated herein and therein has been taken. When executed and delivered by
the Company, each of this Agreement and the Registration Rights Agreement shall
constitute the legal, valid and binding obligation of the Company, enforceable
against the Company in accordance with its terms, except as such may be limited
by bankruptcy, insolvency, reorganization or other laws affecting creditors'
rights generally and by general equitable principles. The Company has all
requisite corporate power to enter into this Agreement and the Registration
Rights Agreement and to carry out and perform its obligations under the terms of
this Agreement, and the Registration Rights Agreement.

                  3.4      Valid Issuance of the Shares. The Shares being
purchased by the Purchasers hereunder will, upon issuance pursuant to the terms
hereof, be duly authorized and validly issued, fully paid and nonassessable.

                  3.5      Financial Statements. The Company has furnished to
each Purchaser its audited Statements of Income, Stockholders' Equity and Cash
Flows for the fiscal year ended December 31, 1999, its audited Balance Sheet as
of December 31, 1999, its unaudited Statements of Income, Stockholders' Equity
and Cash Flows for the period from December 31, 1999 through September 30, 2000
and its unaudited Balance Sheet as of September 30, 2000. All such financial
statements are hereinafter referred to collectively as the "FINANCIAL
STATEMENTS". The Financial Statements have been prepared in accordance with
generally accepted accounting principles applied on a consistent basis during
the periods involved, and fairly present, in all material respects, the
financial position of the Company and the results of its operations as of the
date and for the periods indicated thereon, except that the unaudited financial
statements may not be in accordance with generally accepted accounting
principles because of the absence of footnotes normally contained therein and
are subject to normal year-end audit adjustments which, individually, and in the
aggregate, will not be material. Since September 30, 2000 to the Company's
knowledge, there has been no material adverse change (actual or threatened) in
the assets, liabilities (contingent or other), affairs, operations, prospects or
condition (financial or other) of the Company.

                  3.6      SEC Documents. The Company has furnished to each
Purchaser, a true and complete copy of the Company's Annual Report on Form 10-K,
as amended, for the year ended December 31, 1999, the Company's Quarterly
Reports on Form 10-Q for three months ended March 31, 2000, June 30, 2000 and
September 30, 2000 and any other statement, report, registration statement

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(other than registration statements on Form S-8) or definitive proxy statement
filed by the Company with the SEC during the period commencing December 31, 1999
and ending on the date hereof. The Company will, promptly upon the filing
thereof, also furnish to each Purchaser all statements, reports (including,
without limitation, Quarterly Reports on Form 10-Q and Current Reports on Form
8-K), registration statements and definitive proxy statements filed by the
Company with the SEC during the period commencing on the date hereof and ending
on the Closing Date (all such materials required to be furnished to each
Purchaser pursuant to this sentence or pursuant to the next preceding sentence
of this Section 3.6 being called, collectively, the "SEC DOCUMENTS"). Except as
set forth on Schedule 3.6, as of their respective filing dates, the SEC
Documents complied or will comply in all material respects with the requirements
of the Exchange Act or the Securities Act, as applicable, and none of the SEC
Documents contained or will contain any untrue statement of a material fact or
omitted or will omit to state a material fact required to be stated therein or
necessary in order to make the statements made therein, in light of the
circumstances under which they were made, not misleading, as of their respective
filing dates, except to the extent corrected by a subsequently filed SEC
Document.

                  3.7      Consents. All consents, approvals, orders and
authorizations required on the part of the Company in connection with the
execution, delivery or performance of this Agreement and the Registration Rights
Agreement and the consummation of the transactions contemplated herein and
therein have been obtained and will be effective as of the Closing Date.

                  3.8      No Conflict. The execution and delivery of this
Agreement and the Registration Rights Agreement by the Company and the
consummation of the transactions contemplated hereby and thereby will not
conflict with or result in any violation of or default (with or without notice
or lapse of time, or both) under, or give rise to a right of termination,
cancellation or acceleration of any obligation or to a loss of a material
benefit under (i) any provision of the Certificate of Incorporation or bylaws of
the Company or (ii) any agreement or instrument, permit, franchise, license,
judgment, order, statute, law, ordinance, rule or regulations, applicable to the
Company or its respective properties or assets.

                  3.9      Brokers or Finders. Except for Pacific Growth
Equities, Inc. ("PGE") and Fortis Securities, Inc. ("FORTIS"), the Company has
not dealt with any broker or finder in connection with the transactions
contemplated by this Agreement, and, except for certain fees and expenses
payable by the Company to PGE and Fortis, the Company has not incurred, and
shall not incur, directly or indirectly, any liability for any brokerage or
finders' fees or agents commissions or any similar charges in connection with
this Agreement or any transaction contemplated hereby.

                  3.10     Nasdaq National Market. The Common Stock is listed on
the Nasdaq National Market System, and there are no proceedings to revoke or
suspend such listing.

                  3.11     Absence of Litigation. There is no action, suit or
proceeding or, to the Company's knowledge, any investigation, pending, or to the
Company's knowledge, threatened by or before any governmental body against the
Company and in which an unfavorable outcome, ruling or finding in any said
matter, or for all matters taken as a whole, might have a material adverse
effect on the Company. The foregoing includes, without limitation, any such
action, suit, proceeding or investigation that questions this Agreement or the
Registration Rights Agreement or the right of the Company to execute, deliver
and perform under same.

                  3.12     No Bad Acts. The Company represents and warrants
that, to the best of its knowledge, none of its directors or officers is or has
been the subject of, or a defendant in: (i) an enforcement action or prosecution
(or settlement in lieu thereof) brought by a governmental authority relating to
a violation of securities, fiduciary or criminal laws, or (ii) a civil action
(or settlement in lieu thereof) brought by shareholders or investors for
violation of duties owed to the shareholders or investors.

                  3.13     Freedom to Operate. To the best of the Company's
knowledge, the conduct by the Company of its businesses, and the manufacture by
the Company of its products, does not conflict with, infringe upon or violate
any patent, copyright, trademark, registration or other intellectual property
right of any other person or entity.

                                       3



         4.       Representations and Warranties of the Purchasers. Each
Purchaser severally for itself, and not jointly with the other Purchasers,
represents and warrants to the Company as follows:

                  4.1      Authorization. All action on the part of such
Purchaser and, if applicable, its officers, directors, shareholders, managers,
members and equityholders necessary for the authorization, execution, delivery
and performance of this Agreement and the Registration Rights Agreement and the
consummation of the transactions contemplated herein and therein has been taken.
When executed and delivered, each of this Agreement and the Registration Rights
Agreement will constitute the legal, valid and binding obligation of such
Purchaser, enforceable against such Purchaser in accordance with its terms,
except as such may be limited by bankruptcy, insolvency, reorganization or other
laws affecting creditors' rights generally and by general equitable principles.
Such Purchaser has all requisite corporate power to enter into each of this
Agreement and the Registration Rights Agreement and to carry out and perform its
obligations under the terms of this Agreement and the Registration Rights
Agreement.

                  4.2      Purchase Entirely for Own Account. Such Purchaser is
acquiring the Shares being purchased by it hereunder for investment, for its own
account, and not for resale or with a view to distribution thereof in violation
of the Securities Act.

                  4.3      Investor Status; Etc. Such Purchaser certifies and
represents to the Company that at the time such Purchaser acquires any of the
Shares, such Purchaser will be an "Accredited Investor" as defined in Rule 501
of Regulation D promulgated under the Securities Act and was not organized for
the purpose of acquiring the Shares. Such Purchaser's financial condition is
such that it is able to bear the risk of holding the Shares for an indefinite
period of time and the risk of loss of its entire investment. Such Purchaser has
been afforded the opportunity to ask questions of and receive answers from the
management of the Company concerning this investment and has sufficient
knowledge and experience in investing in companies similar to the Company in
terms of the Company's stage of development so as to be able to evaluate the
risks and merits of its investment in the Company.

                  4.4      Shares Not Registered. Such Purchaser understands
that the Shares have not been registered under the Securities Act, by reason
of their issuance by the Company in a transaction exempt from the registration
requirements of the Securities Act, and that the Shares must continue to be held
by such Purchaser unless a subsequent disposition thereof is registered under
the Securities Act or is exempt from such registration. The Purchaser
understands that the exemptions from registration afforded by Rule 144 (the
provisions of which are known to it) promulgated under the Securities Act depend
on the satisfaction of various conditions, and that, if applicable, Rule 144 may
afford the basis for sales only in limited amounts.

                  4.5      No Conflict. The execution and delivery of this
Agreement and the Registration Rights Agreement by such Purchaser and the
consummation of the transactions contemplated hereby and thereby will not
conflict with or result in any violation of or default by such Purchaser (with
or without notice or lapse of time, or both) under, or give rise to a right of
termination, cancellation or acceleration of any obligation or to a loss of a
material benefit under (i) any provision of the organizational documents of such
Purchaser or (ii) any agreement or instrument, permit, franchise, license,
judgment, order, statute, law, ordinance, rule or regulations, applicable to
such Purchaser or its respective properties or assets.

                  4.6      Brokers. Such Purchaser has not retained, utilized or
been represented by any broker or finder in connection with the transactions
contemplated by this Agreement.

                  4.7      Consents. All consents, approvals, orders and
authorizations required on the part of such Purchaser in connection with the
execution, delivery or performance of this Agreement and the consummation of the
transactions contemplated herein have been obtained and are effective as of the
Closing Date.

         5.       Conditions Precedent.

                  5.1.     Conditions to the Obligation of the Purchasers to
Consummate the Closing. The obligation of each Purchaser to consummate the
Closing and to purchase and pay for the Shares being

                                       4



purchased by it pursuant to this Agreement is subject to the satisfaction of the
following conditions precedent:

                  (a)      The representations and warranties contained herein
of the Company shall be true and correct on and as of the Closing Date with the
same force and effect as though made on and as of the Closing Date (it being
understood and agreed by each Purchaser that, in the case of any representation
and warranty of the Company contained herein which is not hereinabove qualified
by application thereto of a materiality standard, such representation and
warranty need be true and correct only in all material respects in order to
satisfy as to such representation or warranty the condition precedent set forth
in the foregoing provisions of this Section 5.1(a)).

                  (b)      The Registration Rights Agreement shall have been
executed and delivered by the Company.

                  (c)      The Company shall not have been adversely affected in
any material way prior to the Closing Date; and the Company shall have performed
all obligations and conditions herein required to be performed or observed by
the Company on or prior to the Closing Date.

                  (d)      No proceeding challenging this Agreement or the
transactions contemplated hereby, or seeking to prohibit, alter, prevent or
materially delay the Closing, shall have been instituted before any court,
arbitrator or governmental body, agency or official and shall be pending.

                  (e)      The purchase of and payment for the Shares by the
Purchasers shall not be prohibited by any law or governmental order or
regulation. All necessary consents, approvals, licenses, permits, orders and
authorizations of, or registrations, declarations and filings with, any
governmental or administrative agency or of any other person with respect to any
of the transactions contemplated hereby shall have been duly obtained or made
and shall be in full force and effect.

                  (f)      All instruments and corporate proceedings in
connection with the transactions contemplated by this Agreement to be
consummated at the Closing shall be satisfactory in form and substance to such
Purchaser, and such Purchaser shall have received copies (executed or certified,
as may be appropriate) of all documents which such Purchaser may have reasonably
requested in connection with such transactions.

                  5.2.     Conditions to the Obligation of the Company to
Consummate the Closing. The obligation of the Company to consummate the Closing
and to issue and sell to each of the Purchasers the Shares to be purchased by it
at the Closing is subject to the satisfaction of the following conditions
precedent:

                  (a)      The representations and warranties contained herein
of such Purchaser shall be true and correct on and as of the Closing Date with
the same force and effect as though made on and as of the Closing Date (it being
understood and agreed by the Company that, in the case of any representation and
warranty of each Purchaser contained herein which is not hereinabove qualified
by application thereto of a materiality standard, such representation and
warranty need be true and correct only in all material respects in order to
satisfy as to such representation or warranty the condition precedent set forth
in the foregoing provisions of this Section 5.2(a)).

                  (b)      The Registration Rights Agreement shall have been
executed and delivered by each Purchaser.

                  (c)      The Purchasers shall have performed all obligations
and conditions herein required to be performed or observed by the Purchasers on
or prior to the Closing Date.

                  (d)      No proceeding challenging this Agreement or the
transactions contemplated hereby, or seeking to prohibit, alter, prevent or
materially delay the Closing, shall have been instituted before any court,
arbitrator or governmental body, agency or official and shall be pending.

                                       5


                  (e)      The sale of the Shares by the Company shall not be
prohibited by any law or governmental order or regulation. All necessary
consents, approvals, licenses, permits, orders and authorizations of, or
registrations, declarations and filings with, any governmental or administrative
agency or of any other person with respect to any of the transactions
contemplated hereby shall have been duly obtained or made and shall be in full
force and effect.

                  (f)      Each of the Purchasers shall have executed and
delivered to the Company a Investor Questionnaire, in substantially the form
attached hereto as Exhibit B, pursuant to which each such Purchaser shall
provide information necessary to confirm each such Purchaser's status as an
"accredited investor" (as such term is defined in Rule 501 promulgated under the
Securities Act).

                  (g)      Each of the other Purchasers shall have purchased, in
accordance with this Agreement, the number of shares of Common Stock set forth
opposite its name under the heading "Number of Shares to be Purchased."

                  (h)      All instruments and corporate proceedings in
connection with the transactions contemplated by this Agreement to be
consummated at the Closing shall be satisfactory in form and substance to the
Company, and the Company shall have received counterpart originals, or certified
or other copies of all documents, including without limitation records of
corporate or other proceedings, which it may have reasonably requested in
connection therewith.

         6.       Transfer; Legends.

                  6.1.     Securities Law Transfer Restrictions. No Purchaser
shall sell, assign, pledge, transfer or otherwise dispose or encumber any of the
Shares being purchased by it hereunder, except (i) pursuant to an effective
registration statement under the Securities Act or (ii) pursuant to an available
exemption from registration under the Securities Act and applicable state
securities laws and, if requested by the Company, upon delivery by such
Purchaser of an opinion of counsel reasonably satisfactory to the Company to the
effect that the proposed transfer is exempt from registration under the
Securities Act and applicable state securities laws. Any transfer or purported
transfer of the Shares in violation of this Section 6.1 shall be voidable by the
Company. The Company shall not register any transfer of the Shares in violation
of this Section 6.1. The Company may, and may instruct any transfer agent for
the Company, to place such stop transfer orders as may be required on the
transfer books of the Company in order to ensure compliance with the provisions
of this Section 6.1.

                  6.2.     Legends. Each certificate requesting any of the
Shares shall be endorsed with a legend in substantially the form set forth
below, and each Purchaser covenants that, except to the extent such restrictions
are waived by the Company, it shall not transfer the shares represented by any
such certificate without complying with the restrictions on transfer described
in this Agreement and the legends endorsed on such certificate:

         THE SHARES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
         REGISTERED UNDER THE SECURITIES ACT OF 1933 AND MAY NOT BE
         OFFERED, SOLD, ASSIGNED, PLEDGED TRANSFERRED OR OTHERWISE
         DISPOSED OF IN THE ABSENCE OF AN EFFECTIVE REGISTRATION
         STATEMENT UNDER SAID ACT OR PURSUANT TO AN AVAILABLE EXEMPTION
         FROM REGISTRATION UNDER SAID ACT AND, IF REQUESTED BY THE
         COMPANY, UPON DELIVERY OF AN OPINION OF COUNSEL REASONABLY
         SATISFACTORY TO THE COMPANY THAT THE PROPOSED TRANSFER IS
         EXEMPT FROM SAID ACT.

         7.       Termination; Liabilities Consequent Thereon. This Agreement
may be terminated and the transactions contemplated hereunder abandoned at any
time prior to the Closing only as follows:

                  (a)      by the Purchasers, upon notice to the Company if the
conditions set forth in Section 5.1 shall not have been satisfied on or prior to
February 28, 2001; or

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                  (b)      by the Company, upon notice to the Purchasers if the
conditions set forth in Section 5.2 shall not have been satisfied on or prior to
February 28, 2001; or

                  (c)      at any time by mutual agreement of the Company and
the Purchasers; or

                  (d)      by the Purchasers, if there has been any breach of
any representation or warranty or any material breach of any covenant of the
Company contained herein and the same has not been cured within 15 days after
notice thereof, (it being understood and agreed by each Purchaser that, in the
case of any representation or warranty of the Company contained herein which is
not hereinabove qualified by application thereto of a materiality standard, such
representation or warranty will be deemed to have been breached for purposes of
this Section 7.1(d) only if such representation or warranty was not true and
correct in all material respects at the time such representation or warranty was
made by the Company); or

                  (e)      by the Company, if there has been any breach of any
representation, warranty or any material breach of any covenant of any Purchaser
contained herein and the same has not been cured within 15 days after notice
thereof (it being understood and agreed by the Company that, in the case of any
representation and warranty of the Purchaser contained herein which is not
hereinabove qualified by application thereto of a materiality standard, such
representation or warranty will be deemed to have been breached for purposes of
this Section 7.1(e) only if such representation or warranty was not true and
correct in all material respects at the time such representation or warranty was
made by such Purchaser).

         Any termination pursuant to this Section 7 shall be without liability
on the part of any party, unless such termination is the result of a material
breach of this Agreement by a party to this Agreement in which case such
breaching party shall remain liable for such breach notwithstanding any
termination of this Agreement.

         8.       Miscellaneous Provisions.

                  8.1      Public Statements or Releases. None of the parties to
this Agreement shall make, issue, or release any announcement, whether to the
public generally, or to any of its suppliers or customers, with respect to this
Agreement or the transactions provided for herein, or make any statement or
acknowledgment of the existence of, or reveal the status of, this Agreement or
the transactions provided for herein, without the prior consent of the other
parties, which shall not be unreasonably withheld or delayed, provided, that
nothing in this Section 8.1 shall prevent any of the parties hereto from making
such public announcements as it may consider necessary in order to satisfy its
legal obligations.

                  8.2      Further Assurances. Each party agrees to cooperate
fully with the other party and to execute such further instruments, documents
and agreements and to give such further written assurances, as may be reasonably
requested by the other party to better evidence and reflect the transactions
described herein and contemplated hereby, and to carry into effect the intents
and purposes of this Agreement.

                  8.3      Notification of Effectiveness of Registration
Statement. The Company covenants that it will provide notice to the Purchasers
that the Company's registration statement on Form S-3 registering the Shares
sold hereunder to the Purchasers has been declared effective by the SEC.

                  8.4      Rights Cumulative. Each and all of the various
rights, powers and remedies of the parties shall be considered to be cumulative
with and in addition to any other rights, powers and remedies which such parties
may have at law or in equity in the event of the breach of any of the terms of
this Agreement. The exercise or partial exercise of any right, power or remedy
shall neither constitute the exclusive election thereof nor the waiver of any
other right, power or remedy available to such party.

                  8.5      Pronouns. All pronouns or any variation thereof shall
be deemed to refer to the masculine, feminine or neuter, singular or plural, as
the identity of the person, persons, entity or entities may require.

                                       7



                  8.6      Notices.

                  (a)      Any notices, reports or other correspondence
(hereinafter collectively referred to as "CORRESPONDENCE") required or permitted
to be given hereunder shall be sent by postage prepaid first class mail, courier
or telecopy or delivered by hand to the party to whom such correspondence is
required or permitted to be given hereunder. The date of giving any notice shall
be the date of its actual receipt.

                  (b)      All correspondence to the Company shall be addressed
as follows:

                           La Jolla Pharmaceutical Company
                           6455 Nancy Ridge Drive
                           San Diego, California  92121
                           Attention: Steven B. Engle
                           Telecopier: (858) 452-6893

                                       8



                           with a copy to:

                           Gibson, Dunn & Crutcher LLP
                           4 Park Plaza
                           Irvine, California 92614
                           Attention:  Leonard J. McGill
                           Telecopier: (949) 451-4220

                  (c)      All correspondence to any Purchaser shall be sent to
such Purchaser at the address set forth in Exhibit A.

                  (d)      Any entity may change the address to which
correspondence to it is to be addressed by notification as provided for herein.

                  8.7      Captions. The captions and paragraph headings of this
Agreement are solely for the convenience of reference and shall not affect its
interpretation.

                  8.8      Severability. Should any part or provision of this
Agreement be held unenforceable or in conflict with the applicable laws or
regulations of any jurisdiction, the invalid or unenforceable part or provisions
shall be replaced with a provision which accomplishes, to the extent possible,
the original business purpose of such part or provision in a valid and
enforceable manner, and the remainder of this Agreement shall remain binding
upon the parties hereto.

                  8.9      Governing Law; Injunctive Relief.

                  (a)      This Agreement shall be governed by and construed in
accordance with the internal and substantive laws of the State of California and
without regard to any conflicts of laws concepts that would apply the
substantive law of some other jurisdiction.

                  (b)      Each of the parties hereto acknowledges and agrees
that damages will not be an adequate remedy for any material breach or violation
of this Agreement if such material breach or violation would cause immediate and
irreparable harm (an "IRREPARABLE BREACH"). Accordingly, in the event of a
threatened or ongoing Irreparable Breach, each party hereto shall be entitled to
seek, in any state or federal court in the State of California, equitable relief
of a kind appropriate in light of the nature of the ongoing or threatened
Irreparable Breach, which relief may include, without limitation, specific
performance or injunctive relief; provided, however, that if the party bringing
such action is unsuccessful in obtaining the relief sought, the moving party
shall pay the non-moving party's costs, including actual attorney's fees,
incurred in connection with defending such action. Such remedies shall not be
the parties' exclusive remedies, but shall be in addition to all other remedies
provided in this Agreement.

                  8.10     Waiver. No waiver of any term, provision or condition
of this Agreement, whether by conduct or otherwise, in any one or more
instances, shall be deemed to be, or be construed as, a further or continuing
waiver of any such term, provision or condition or as a waiver of any other
term, provision or condition of this Agreement.

                  8.11     Expenses. Each party will bear its own costs and
expenses in connection with this Agreement.

                  8.12     Assignment. The rights and obligations of the parties
hereto shall inure to the benefit of and shall be binding upon the authorized
successors and permitted assigns of each party. Neither party may assign its
rights or obligations under this Agreement or designate another person (i) to
perform all or part of its obligations under this Agreement or (ii) to have all
or part of its rights and benefits under this Agreement, in each case without
the prior written consent of the other party. In the event of any assignment in
accordance with the terms of this Agreement, the assignee shall specifically
assume and be bound by the provisions of the Agreement by executing and agreeing
to an assumption agreement reasonably acceptable to the other party.

                                       9



                  8.13     Survival. The respective representations and
warranties given by the parties hereto, and the other covenants and agreements
contained herein, shall survive the Closing Date and the consummation of the
transactions contemplated herein for a period of two years, without regard to
any investigation made by any party.

                  8.14     Entire Agreement. This Agreement along with the
exhibits attached hereto and incorporated herewith constitute the entire
agreement between the parties hereto respecting the subject matter hereof and
supersedes all prior agreements, negotiations, understandings, representations
and statements respecting the subject matter hereof, whether written or oral. No
modification, alteration, waiver or change in any of the terms of this Agreement
shall be valid or binding upon the parties hereto unless made in writing and
duly executed by the Company and the Majority Purchasers.

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         IN WITNESS WHEREOF, the parties hereto have executed this Stock
Purchase Agreement as of the day and year first above written.

                                          LA JOLLA PHARMACEUTICAL COMPANY

                                          By: _________________________________
                                              Steven B. Engle
                                              Chief Executive Officer

THE PURCHASER'S SIGNATURE TO THE INVESTOR QUESTIONNAIRE DATED EVEN DATE HEREWITH
SHALL CONSTITUTE THE PURCHASER'S SIGNATURE TO THIS STOCK PURCHASE AGREEMENT.