Stock Purchase Agreement

Stock Purchase Agreement




                                                                    EXHIBIT 10.1





                            STOCK PURCHASE AGREEMENT


         This STOCK PURCHASE AGREEMENT (this  "Agreement"),  dated as of May 24,
1997, is entered into by and between NEORX CORPORATION, a Washington corporation
(the  "Company"),  and SCHWARZ  PHARMA AG, a corporation  organized and existing
under the laws of the Federal Republic of Germany (the "Investor").

                                     RECITAL

         The  Investor  desires to purchase  from the  Company,  and the Company
desires to sell to the Investor,  shares of the Company's common stock, upon the
terms and conditions set forth herein and in connection  with the execution of a
separate Development and Distribution Agreement, dated as of even date herewith.

                                    AGREEMENT

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

1.       Purchase and Sale

         The Investor hereby agrees to purchase  shares of the Company's  common
stock  (the  "Shares")  from the  Company  for an  aggregate  purchase  price as
specified by the Investor (the "Purchase Price"), but not to exceed Four Million
U.S.  Dollars (US  $4,000,000).  The Company  hereby  agrees to issue,  sell and
deliver to the Investor in exchange for the Purchase Price that number of Shares
determined to the nearest whole number by dividing (a) the Purchase Price by (b)
the product of 1.5 multiplied by the average of the last reported sales price of
the Company's  common stock on the Nasdaq  National Market as reported by Nasdaq
on each of the 20 trading days immediately preceding the date of this Agreement.

         The closing of this purchase and sale of the Shares shall take place at
the offices of Perkins Coie, Seattle, Washington, on the date hereof and at such
time as may be mutually  agreed upon between the Company and the  Investor  (the
"Closing").  At the Closing,  the Investor  shall pay the Purchase  Price to the
Company by bank wire transfer to the account  designated  by the Company.  After
receipt of the Purchase Price, the Company shall (a) deliver to the Investor, or
instruct  its  transfer  agent  to  deliver  to  the  Investor,   a  certificate
representing the Shares,  (b) deliver a legal opinion to the Investor,  dated as
of the date of this Agreement,  and (c) cause its special counsel, Perkins Coie,
to deliver an opinion to the Investor, dated as of the date of this Agreement.



2.       Representations and Warranties of the Investor Regarding the Shares

         The Investor  hereby  represents  and warrants to the Company as of the
date of this Agreement as follows:

         2.1      High Degree of Risk

         The  Investor  recognizes  that the  Company  has not yet  developed  a
marketable  product and that there can be no assurance  that the Company will be
able to develop a marketable  product or that any such product developed will be
accepted in the marketplace.  There can be no assurance that the Company will be
able to obtain  its  projected  goals,  and the  Company  will need  significant
additional capital to be successful,  which capital may not be readily available
when and as needed.

         2.2      Professional Advice

         The Investor has obtained,  to the extent it deems  necessary,  its own
professional  advice with respect to the risks inherent in the investment in the
Shares,  the condition of the Company and the  suitability  of the investment in
the Shares in light of the Investor's financial condition and investment needs.

         2.3      Sophistication

         The Investor,  either alone or with the assistance of its  professional
advisors,  has such knowledge and  experience in financial and business  matters
that it is  capable  of  evaluating  the  merits  and  risks of the  prospective
investment in the Shares.

         2.4      Suitability

         The Investor has  adequate  net worth and means for  providing  for its
current  financial  needs and  contingencies  and has no need for  liquidity  of
investment  with respect to the Shares.  The  Investor's  overall  commitment to
investments that are illiquid or not readily marketable is not  disproportionate
to its net  worth,  and  investment  in the Shares  will not cause such  overall
commitment to become excessive.

         2.5      Access to Information

         The Investor has been given access to all  information  requested by it
regarding the Company, including, in particular, the current financial condition
of the Company and the risks associated therewith,  and has utilized such access

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to its satisfaction for the purpose of obtaining  information  about the Company
and the Investor has either  attended or been given a reasonable  opportunity to
attend a meeting with  representatives  of the Company for the purpose of asking
questions of, and receiving  answers from, such  representatives  concerning the
terms and  conditions of the offering of the Shares and to obtain any additional
information,  to the  extent  reasonably  available,  necessary  to  verify  the
accuracy of information provided about the Company.

         2.6      Purchase Entirely for Own Account

         The Shares will be  acquired  for  investment  for the  Investor's  own
account,  not as a nominee or agent,  and not with a view to the distribution of
any part thereof. The Investor has no present intention of selling, granting any
participation in or otherwise  distributing the same in a manner contrary to the
Securities Act of 1933, as amended (the "Act"),  including,  without limitation,
Regulation S of the Act  ("Regulation  S"), or any  applicable  state or foreign
securities or Blue Sky laws, and has no agreement or arrangement with any person
to sell, transfer or grant  participations to such person or to any third person
with respect to any of the Shares.

         2.7      Due Diligence

         The  Investor  has been solely  responsible  for its own due  diligence
investigation of the Company and the Company's business, and its own analysis of
the merits and risks of the investment made pursuant to this  Agreement,  and is
not relying on anyone  else's  analysis or  investigation  of the  Company,  its
business or the merits and risks of the Shares other than professionals employed
specifically  by the  Investor to assist the  Investor.  In taking any action or
performing  any role  relative to the  arranging  of the  investment  being made
pursuant to this  Agreement,  the  Investor has acted solely in its own interest
and not in the interest of any other person, and no other person has acted as an
agent or fiduciary for the Investor.

         2.8      Restricted Securities; Compliance with Regulation S

         The Investor  understands  that (a) the Shares have not been registered
under the Act,  (b) the Shares will be issued in reliance on  Regulation  S and,
therefore,  cannot be sold or transferred except in compliance with Regulation S
unless they are subsequently  registered under the Act or another exemption from
such  registration  is  available,  and (c) the  Shares  are  subject  to resale
restrictions  as set forth in Section 2.9 of this Agreement and the Investor may
not be able to liquidate  its  investment in the event of an emergency or pledge
the Shares as collateral  security for loans. In this  connection,  the Investor
represents  that it is familiar  with  Regulation S as currently in effect,  and

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understands  the resale  limitations  imposed thereby and by Section 2.9 of this
Agreement. The Investor acknowledges and understands that the Company's reliance
upon such exemptions  under Regulation S is predicated in part on the Investor's
representations  contained  herein.  The Investor is not a U.S.  person (as that
term is used in  Regulation  S), is not located in the U.S. and is acquiring the
Shares in an offshore transaction, and such Investor is not acquiring the Shares
for the  account  or  benefit  of any U.S.  person.  The  Investor  has not,  in
connection with the purchase of Shares  hereunder,  offered,  sold (including by
any short sale), or entered into any transaction  (including the purchase of any
put or sale of any call)  involving  the sale or  potential  sale of the  common
stock of the Company in the United States or to or for the account or benefit of
any U.S. person.

         2.9      Restrictions on Disposition

         (a) For the  period  of one  year  from the  date of the  Closing,  the
Investor may not sell,  assign or otherwise  transfer  any  interest,  direct or
indirect,  in all or any  part of the  Shares  or enter  into  any  transaction,
including  the  purchase  of any  put or sale of any  call  or any  short  sale,
involving the sale or potential sale of the Company's common stock.

         (b) Without in any way limiting  the  covenants  set forth  above,  the
Investor further agrees not to make any disposition of all or any portion of the
Shares unless and until:

                   (i) if  reasonably  requested  by the  Company,  the Investor
shall have  furnished the Company with an opinion of counsel  (which opinion may
be delivered by the Investor's in-house counsel), reasonably satisfactory to the
Company,  that such  disposition  will not require  registration  of such shares
under the Act; and

                  (ii) the Company shall have been  satisfied that such proposed
disposition  complies in all respects with  Regulation S or any  successor  rule
providing a safe harbor for such disposition without registration.

         (c) In addition to the  foregoing  provisions  of this  Section 2.9, in
order to preserve an orderly market for the Company's common stock, (A) at least
five business days prior to any such proposed  disposition,  the Investor  shall
provide  to the  Company  notice of such  disposition;  (B) the  Investor  shall
provide  the Company or its agent an  opportunity  to arrange the sale to one or
more parties of the Shares  proposed to be transferred and shall cooperate fully
with the Company or such agent in such  process  (including  discussions  of the
terms of such sale with no more than two brokers  designated  by the Company and
to sell such Shares to one or both of such  brokers if an agreement is reached);
and (C) if, after three  business  days from the date the notice  referred to in

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subparagraph (c)(i)(A) is received by the Company, an agreement regarding such a
sale has not been reached, the Investor may dispose of such Shares in any manner
it so chooses so long as such disposition is not in violation of this Agreement,
and the Company agrees to immediately  cause its transfer agent to issue a clean
certificate  evidencing the Shares,  without any restrictive legend thereon,  if
applicable  securities  laws do not  require a legend,  restriction  or  holding
period.

         2.10     Domicile; Principal Place of Business

         The Investor  represents that it is domiciled in, and has its principal
place of business in, the  jurisdiction set forth in the first paragraph of this
Agreement.

         2.11     Legends

         It is understood that the certificate evidencing the Shares will bear a
legend as follows:

                  "THE SECURITIES  EVIDENCED BY THIS  CERTIFICATE  HAVE NOT BEEN
                  REGISTERED  UNDER THE U.S.  SECURITIES ACT OF 1933 (THE "ACT")
                  OR THE SECURITIES LAWS OF ANY STATE. THE SECURITIES  EVIDENCED
                  BY THIS CERTIFICATE HAVE BEEN ISSUED IN A TRANSACTION GOVERNED
                  BY  REGULATION  S  PROMULGATED  UNDER  THE  ACT AND MAY NOT BE
                  TRANSFERRED  EXCEPT IN ACCORDANCE  WITH SAID  REGULATION S, OR
                  PURSUANT  TO  AN  EFFECTIVE   REGISTRATION   STATEMENT  OR  AN
                  APPLICABLE EXEMPTION FROM REGISTRATION UNDER THE ACT.

                  THE SECURITIES  EVIDENCED BY THIS  CERTIFICATE  ARE SUBJECT TO
                  CERTAIN RESALE  RESTRICTIONS  AS SET FORTH IN A STOCK PURCHASE
                  AGREEMENT DATED AS OF MAY 23, 1997, A COPY OF WHICH IS ON FILE
                  AT THE PRINCIPAL OFFICE OF THE COMPANY."

         2.12     Acknowledgment

         The Investor, by executing below, acknowledges that it understands that
the Company is relying upon the accuracy and completeness of its representations
and warranties set forth in this Agreement in deciding whether to sell shares of
the Company's  common stock to the Investor and in complying  with the Company's
obligations under applicable securities laws.

                                      -5-


3.       Representations and Warranties of the Investor

         The Investor  hereby  represents  and warrants to the Company as of the
date of this Agreement as follows:

         3.1      Organization and Existence

         The Investor is a corporation  duly organized,  validly existing and in
good  standing  under the laws of the  Federal  Republic  of Germany and has all
requisite  power and  authority  to enter into and perform this  Agreement.  The
Investor has  furnished to the Company  complete and accurate  information  with
respect to the beneficial owners of the Investor.  The Investor agrees to update
this information promptly if the beneficial owners of the Investor change at any
time.

         3.2      Authorization

         The  execution,  delivery  and  performance  by the  Investor  of  this
Agreement have been duly  authorized by all necessary  action on the part of the
Investor.  This  Agreement  constitutes  a valid and  binding  agreement  of the
Investor,   enforceable  in  accordance   with  its  terms  except  as  (a)  the
enforceability thereof may be limited by bankruptcy,  insolvency or similar laws
affecting  creditors'  rights  generally and (b) the  availability  of equitable
remedies may be limited by equitable principles of general applicability.

         3.3      Governmental Authorization

         No consent, approval or authorization of or designation, declaration or
filing with any  governmental  authority on the part of the Investor is required
in connection  with the valid  execution  and delivery of this  Agreement or the
purchase of the Shares.

         3.4      Noncontravention

         The  execution,  delivery  and  performance  by the  Investor  of  this
Agreement do not and will not (a) contravene or conflict with the organizational
documents of the Investor;  (b) assuming compliance with the matters referred to
in Section 3.3 hereof,  contravene or conflict with or constitute a violation of
any  provision of any law,  regulation,  judgment,  injunction,  order or decree
binding upon or applicable to the Investor; or (c) constitute a default under or
give rise to any  right of  termination,  cancellation  or  acceleration  of any
material right or obligation of the Investor under any provision of any material
agreement, contract or other instrument binding upon the Investor.

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         3.5      Finders' Fees

         There is no investment banker, broker, finder or other intermediary who
has been  retained by or is  authorized to act on behalf of the Investor and who
might be entitled to any fee or commission  from the Investor in connection with
the transactions contemplated by this Agreement.

         3.6      Financing

         The Investor has sufficient funds available to purchase the Shares.

4.       Representations and Warranties of the Company

         The Company  hereby  represents  and warrants to the Investor as of the
date of this Agreement as follows:

         4.1      Corporate Organization

         The Company is a corporation  duly organized,  validly  existing and in
good standing  under the laws of the State of  Washington  and has all requisite
power and authority to enter into and perform this Agreement.

         4.2      Corporate Authorization

         The  execution,  delivery  and  performance  by  the  Company  of  this
Agreement  are within the  corporate  powers of the  Company  and have been duly
authorized by all necessary  corporate  action on the part of the Company.  This
Agreement constitutes a valid and binding agreement of the Company,  enforceable
in  accordance  with its terms except as (a) the  enforceability  thereof may be
limited by bankruptcy,  insolvency or similar laws affecting  creditors'  rights
generally  and (b) the  availability  of  equitable  remedies  may be limited by
equitable principles of general applicability.

         4.3      Governmental Authorization

         No consent, approval or authorization of or designation, declaration or
filing with any governmental authority on the part of the Company is required in
connection with the valid execution and delivery of this Agreement or the offer,
sale or issuance of the Shares,  except qualification or registration (or taking
such action as may be  necessary to secure an exemption  from  qualification  or
registration,  if  available)  of the  offer  and sale of the  Shares  under all
applicable federal and state securities laws, which filings and  qualifications,
if required, will be accomplished in a timely manner.

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         4.4      Noncontravention

         The  execution,  delivery  and  performance  by  the  Company  of  this
Agreement do not and will not (a)  contravene  or conflict  with the Articles of
Incorporation or Bylaws of the Company; (b) assuming compliance with the matters
referred to in Section 4.3 hereof,  contravene  or conflict with or constitute a
violation of any provision of any law, regulation,  judgment,  injunction, order
or decree  binding upon or applicable to the Company;  (c)  constitute a default
under or give rise to any right of termination,  cancellation or acceleration of
any  material  right or  obligation  of the Company  under any  provision of any
material  agreement,  contract or other instrument binding upon the Company;  or
(d)  result  in the  creation  or  imposition  of any  lien on any  asset of the
Company.

         4.5      Validity of the Shares

         The Shares have been duly  authorized and, when issued and delivered to
and paid for by the Investor pursuant to this Agreement, will be validly issued,
fully paid and nonassessable,  and such shares are free of preemptive or similar
rights.

         4.6      Capitalization

         There has been no material  change in the  authorized  capital stock of
the Company as  disclosed in the  Company's  Report on Form 10-Q for the quarter
ended March 31, 1997.

         4.7      Nasdaq National Market

         The Company's  common stock is quoted on the Nasdaq National Market and
the Company is in compliance with the applicable provisions of Schedule D to the
By-laws of the National Association of Securities Dealers, Inc.

         4.8      Finders' Fees

         There is no investment banker, broker, finder or other intermediary who
has been  retained by or is  authorized  to act on behalf of the Company and who
might be entitled to any fee or commission  from the Company in connection  with
the transactions contemplated by this Agreement.

5.       Public Reports

         The Company has  provided to the Investor  true and complete  copies of
all reports,  proxy statements and other documents (the "Public  Reports") filed
by the  Company  with the SEC  under the  Securities  Exchange  Act of 1934,  as
amended (the  "Exchange  Act"),  since  December 31,  1996.  The Public  Reports

                                      -8-


include all the reports the Company has been required to file under the Exchange
Act since that date. As of their  respective  dates,  none of the Public Reports
contained any untrue statement of a material fact or omitted to state a material
fact required to be stated  therein or necessary in order to make the statements
therein not misleading.

6.       Miscellaneous

         6.1      Notices

         Any notice required or permitted to be given under this Agreement shall
be in writing, shall specifically refer to this Agreement and shall be effective
on receipt, when given by registered airmail or overnight courier and addressed,
unless otherwise specified in writing, to the addresses described below.

         For NeoRx:

                         NeoRx Corporation
                         410 West Harrison
                         Seattle, Washington 98119-4007
                         Attn:  President

         with a copy (which shall not constitute notice) to:

                         Perkins Coie
                         1201 Third Avenue, 40th Floor
                         Seattle, Washington 98101-3099
                         Fax:  (206) 583-8500
                         Attn: James R. Lisbakken

         For Schwarz Pharma:

                         Schwarz Pharma AG
                         Alfred-Nobel-Str. 10
                         40789 Monheim
                         Germany
                         Attn:  President

         6.2      Amendments; No Waivers

         (a) Any  provision of this  Agreement  may be amended or waived if, and
only if, such  amendment  or waiver is in writing and signed,  in the case of an

                                      -9-


amendment,  by the Investor and the Company or, in the case of a waiver,  by the
party against whom the waiver is to be effective.

         (b) No failure or delay by either party in exercising any right,  power
or privilege hereunder shall operate as a waiver thereof nor shall any single or
partial  exercise  thereof preclude any other or further exercise thereof or the
exercise of any other right, power or privilege.  The rights and remedies herein
provided  shall be  cumulative  and not  exclusive  of any  rights  or  remedies
provided by law.

         6.3      Expenses

         All costs and expenses incurred in connection with this Agreement shall
be paid by the party incurring such cost or expense.

         6.4      Successors and Assigns

         The provisions of this Agreement shall be binding upon and inure to the
benefit of the parties  hereto and their  respective  successors  and  permitted
assigns;  PROVIDED that neither party may assign, delegate or otherwise transfer
any of its rights or obligations under this Agreement without the consent of the
other party hereto.

         6.5      Governing Law

         The Investor agrees that this Agreement shall be enforced, governed and
construed  in  all  respects  in  accordance  with  the  laws  of the  State  of
Washington,  and that the rights,  powers and duties set forth  herein  shall be
binding upon the Investor and its  successors and permitted  assigns,  and shall
inure to the benefit of its successors and permitted assigns.

         6.6      Counterparts; Effectiveness

         This  Agreement  may be signed in any number of  counterparts,  each of
which shall be an original,  with the same effect as if the  signatures  thereto
and hereto were upon the same instrument.  This Agreement shall become effective
when each party hereto shall have  received a  counterpart  hereof signed by the
other party hereto.

         6.7      Entire Agreement

         This Agreement  constitutes  the entire  agreement  between the parties
with respect to the subject matter hereof and  supersedes all prior  agreements,
understandings and negotiations, both written and oral, between the parties with
respect to the subject matter of this Agreement. No representation,  inducement,
promise, understanding, condition or warranty not set forth herein has been made

                                      -10-


or relied upon by either party hereto.  Neither this Agreement nor any provision
hereof is intended to confer upon any person  other than the parties  hereto any
rights or remedies hereunder.

         6.8      Captions

         The captions  herein are included for convenience of reference only and
shall be ignored in the construction or interpretation hereof.

         6.9      Lock-Up Agreement

         The Investor  agrees that,  if requested by the Company in  conjunction
with an  underwritten  public  offering,  the Investor will enter into a written
agreement that it will not,  directly or indirectly,  offer,  sell,  contract to
sell,  grant any option to  purchase,  make any short sale,  pledge or grant any
interest in, or otherwise  dispose of,  transfer or make a  distribution  of any
shares of the  Company's  common  stock for a period of 180 days  after the date
such public offering is declared effective by the SEC.

         6.10     Survival

         Notwithstanding  any investigation made by any party to this Agreement,
all covenants,  agreements,  representations  and warranties made by the Company
and  the  Investor  herein  and in the  certificates  for the  Shares  delivered
pursuant hereto shall survive the execution of this  Agreement,  the delivery to
the Investor of the Shares being purchased and the payment therefor.

         IN WITNESS WHEREOF,  the parties hereto have executed this Agreement as
of the date first written above.

                                      NEORX CORPORATION

                                      By    /S/ PAUL G. ABRAMS
                                            -----------------------------
                                      Its   PRESIDENT AND CHIEF EXECUTIVE
                                             OFFICER


SCHWARZ PHARMA AG                     SCHWARZ PHARMA AG

By   /S/ PATRICK SCHWARZ-SCHUTTE      By    /S/ LARS EKMAN
     ---------------------------            ------------------------------
Its  CHIEF EXECUTIVE OFFICER          Its   VICE PRESIDENT OF RESEARCH


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