<PAGE>

                                                                    EXHIBIT 10.6



CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY WITH
THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE
OMITTED PORTION.


                               BETA TEST AGREEMENT

         This Agreement is made effective as of the 1st day of March, 2001,
between BioNumerik Pharmaceuticals, Inc., with a place of business at 8122
Datapoint Drive, Suite 1250, San Antonio, Texas 78229 ("BioNumerik"), and Cray
Inc., with a place of business at 411 1st Avenue S. Suite 600, Seattle, WA
98104-2860 ("CRAY").

                                    RECITALS:

         WHEREAS BioNumerik and a predecessor of CRAY entered into a Beta Test
Agreement, dated as of August 18, 1994, as amended.

         WHEREAS, BioNumerik and CRAY wish to amend and restate the Beta Test
Agreement to add Cray as a party and provide for the use and evaluation of
computer systems and software and the provision of certain services different
from those described in the original Beta Test Agreement.

         WHEREAS, BioNumerik and CRAY have therefore determined to amend and
restate the Beta Test Agreement with amended terms that will govern the
relationship between the parties with respect to such computer systems, software
and services.

         WHEREAS, this Agreement is a contractual arrangement between CRAY and
BioNumerik in which CRAY will provide BioNumerik with the use of certain CRAY
products for the purposes of testing the products and BioNumerik will provide to
CRAY information and data pertaining to their testing which CRAY may use without
charge to modify, improve or market the products,

         Now, therefore, the parties agree as follows:

1.       Definitions. For purpose of this Agreement, the following words, terms
         and phrases shall have the meanings set forth below:

         1.1      "Beta Test Period" shall mean the period of time described in
                  Section 2.1 during which testing of and adjustments to the
                  products contemplated hereunder will be undertaken.

         1.2      "Equipment" shall mean the computer system products described
                  in Exhibit A to this Agreement, together with any additions,
                  modifications or enhancements thereto provided by CRAY under
                  the terms of this Agreement.


<PAGE>

         1.3      "Software" shall mean the software products described in
                  Exhibit A to this Agreement, together with any additions,
                  modifications or enhancements thereto provided by CRAY under
                  the terms of this Agreement.

         1.4      "Documentation" shall mean the user manuals and other
                  documentation with respect to the Equipment and Software that
                  are provided to BioNumerik during the term of this Agreement.

         1.5      "Products" shall mean Equipment, Software and Documentation.

         1.6      "Principal Contacts" shall mean the individuals designated by
                  the parties to act as principal points of contact regarding
                  matters related to this Agreement.

         1.7      "Confidential Information" shal1 mean the Software, and all
                  other information that is (i) disclosed by either party in any
                  tangible form and clearly labeled or marked as confidential,
                  proprietary or its equivalent, or (ii) disclosed by either
                  party orally or visually, and designated confidential,
                  proprietary or its equivalent at the time of its disclosure
                  and summarized in writing and clearly marked or labeled as
                  confidential, proprietary or its equivalent within thirty (30)
                  days of disclosure.

2.       Beta Test Period and Obligations.

         2.1      Beta Test Period. BioNumerik agrees to act as a beta test site
                  for the Products for the Beta Test Period. The Beta Test
                  Period shall be the term of this Agreement.

         2.2      Beta Test Site. The beta test site shall be the principal
                  offices of BioNumerik located at the address set forth above.

         2.3      Beta Test Obligations. During the Beta Test Period, BioNumerik
                  and CRAY shall each undertake and perform their respective
                  obligations as set forth below.

         2.4      Specifications. BioNumerik shall participate with CRAY in the
                  development of the specifications for the installation and
                  operation of the Products.

         2.5      Testing. During the Beta Test Period BioNumerik agrees to run
                  such test suites and other test programs as may be provided by
                  CRAY. CRAY may request that BioNumerik use special and
                  non-standard operating procedures for the testing of the
                  Products; BioNumerik shall not unreasonably withhold its
                  consent to such a request.

         2.6      Error Notice. BioNumerik's Principal Contact shall notify
                  CRAY's Principal Contact of any material failure, error or
                  other malfunction of any part of the Products.



                                                             BETA TEST AGREEMENT
                                                                          PAGE 2

<PAGE>

         2.7      Access. During the Beta Test Period, BioNumerik will grant
                  CRAY access to the Products and allow CRAY to gain access to
                  the operational data contemplated under this Agreement at such
                  reasonable times as may be required by CRAY for the reasonable
                  purposes of CRAY with respect to the development and sale of
                  their equipment.


                                                             BETA TEST AGREEMENT
                                                                          PAGE 3

<PAGE>

         2.8      Modifications. During the Beta Test Period, BioNumerik's
                  Principal Contact will consult with CRAY 's Principal Contact
                  regarding the performance of the Products and will evaluate
                  the test data and error reports provided by BioNumerik. Should
                  CRAY modify or improve the Products as a result of
                  BioNumerik's testing, CRAY will provide such modification or
                  improvement to BioNumerik at no cost.

         2.9      Use. During the term of this Agreement, CRAY shall loan the
                  Products to BioNumerik. BioNumerik shall use the Products only
                  for the evaluation of the Products under this Agreement and
                  BioNumerik's internal business purposes. Subject to Section
                  12.6, BioNumerik will not offer for sale or otherwise offer or
                  deliver the Products to any third party. BioNumerik will at
                  all times cause the Products to be maintained and operated by
                  qualified personnel in accordance with applicable manuals,
                  will keep the Products in the environment specified in CRAY's
                  Site Planning Manual, and will comply with the requirements of
                  CRAY's insurers which are provided to BioNumerik in writing.
                  CRAY may at any time during normal business hours inspect the
                  Products to ascertain compliance with this Section 2.9. Any
                  equipment which BioNumerik purchases from CRAY during or prior
                  to the period of this agreement, will be wholly owned by
                  BioNumerik and governed only by the term of the purchase
                  contract, but portions of such systems which are not
                  purchased, but provided by CRAY and added to the Products
                  list, will be covered under this agreement.

         2.10     License. CRAY hereby grants a single, non-transferable and
                  non-exclusive license to use the Software during the term of
                  this Agreement. No rights to sublicense or distribute the
                  Software are granted. All rights not specifically granted to
                  BioNumerik by this license shall remain in CRAY. CRAY may
                  include features in the Software which restrict unlicensed use
                  or use of the Software or related data after license
                  expiration. The Software may be used by BioNumerik only on the
                  Equipment or on equipment purchased by BioNumerik from CRAY.
                  BioNumerik shall not modify, clone, reverse assemble, or
                  reverse compile any part of the Software or adopt any part of
                  the Software as its own. BioNumerik shall not translate the
                  Software into a computer language (e.g., FORTRAN or "C")
                  different from the language in which it was provided to
                  BioNumerik by CRAY. BioNumerik is licensed to use only the
                  binary format of the Software unless otherwise agreed in
                  writing by CRAY. The Software is not designed or licensed for
                  use in on-line control equipment in hazardous environments
                  such as operation of nuclear facilities, aircraft navigation
                  or control, life support systems or medical procedures.
                  BioNumerik assumes all risk for any such application and
                  agrees to indemnify CRAY and its suppliers for any and all
                  damages that may be incurred due to the use of Software in
                  such applications. BioNumerik acknowledges that the Software
                  is proprietary and shall remain the property of CRAY or its
                  suppliers. Notwithstanding the foregoing, BioNumerik shall
                  retain all ownership and rights to and may freely use
                  BioNumerik's own proprietary drug design and molecular
                  simulation software and no license is granted to CRAY with
                  respect to such software.



                                                             BETA TEST AGREEMENT
                                                                          PAGE 4

<PAGE>

         2.11     Subject to CRAY 's business priorities and needs, CRAY shall
                  provide reasonable technical assistance to BioNumerik in the
                  use and operation of the Products.

3.       Product Installation. BioNumerik will ensure that the site is
         adequately prepared to receive the Products. CRAY will ship the
         Products at no cost to BioNumerik, install them and run its tests to
         verify proper installation. The Products shall be installed by CRAY at
         the times described in Exhibit B hereto. BioNumerik shal1 cooperate and
         assist with the installation of the Products as reasonably necessary.
         Upon sixty (60) days notice to BioNumerik, CRAY shall also be permitted
         to install any modifications to the Products CRAY deems necessary to
         the proper function of the Products or to achieve the objectives of
         this Agreement. During the term of this Agreement, the parties may
         agree to the installation of other equipment or software that is
         additional to the Equipment or Software, or a modification to the
         Equipment or Software. All such additional equipment or modifications
         shall be deemed Equipment or Software that is subject to the terms of
         this Agreement. In addition to the use of the Products and to
         facilitate BioNumerik's performance of its obligations hereunder,
         during the term of this Agreement CRAY shall grant BioNumerik access to
         the CRAY datacenter systems described in Exhibit A to this Agreement,
         subject to the availability of such systems in CRAY 's datacenter and
         CRAY s business priorities and needs.

4.       Title and Risk of Loss. Title to all Products remains with CRAY.
         BioNumerik shall not sell the Products or encumber their title. CRAY
         assumes all risk of loss of or damage to Products throughout the Beta
         Test Period, except that BioNumerik will be responsible for loss or
         damage caused by negligence of BioNumerik or by environmental factors
         at the installation site.

5.       Obligations of BioNumerik. During the term of this Agreement,
         BioNumerik shall evaluate the Products and provide the results of that
         evaluation to CRAY as services described in Exhibit B to this
         Agreement, and shall provide the other services described in that
         Exhibit B in the times and in the manner described therein.

6.       Principal Contacts. Each party shall designate an individual to act as
         the primary point of contact with the other party with respect to
         issues related to the use of the Products, the obligations of
         BioNumerik and other matters related to this Agreement. The initial
         Principal Contacts are designated in Exhibit D to this Agreement. A
         party may change its Principal Contact by giving notice to the other
         party.

7.       Warranty. THE PRODUCTS PROVIDED TO BIONUMERIK UNDER THIS AGREEMENT ARE
         PROVIDED "AS IS", AND CRAY MAKES NO WARRANTY OF ANY KIND WITH RESPECT
         TO THE PRODUCTS, INCLUDING BUT NOT LIMITED TO ANY WARRANTY OF
         MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR FREEDOM FROM
         VIOLATION OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS, WHICH ARE HEREBY
         SPECIFICALLY EXCLUDED.



                                                             BETA TEST AGREEMENT
                                                                          PAGE 5

<PAGE>

8.       Indemnification.

         8.1      Cray shall indemnify BioNumerik and hold BioNumerik harmless
                  from all damages and all reasonable expenditures incurred by
                  BioNumerik as the result of any charge or claim of copyright
                  infringement or violation of proprietary rights asserted
                  against BioNumerik by third parties as a result of
                  BioNumerik's use of the Products hereunder, provided that CRAY
                  is given prompt notice of any such claim and BioNumerik
                  provides reasonable assistance to CRAY in connection with such
                  claims.

         8.2      Should the Products become, or in CRAY's opinion be likely to
                  become, the subject of a claim of infringement of a copyright
                  or violation of proprietary rights of another, CRAY may either
                  (i) procure for BioNumerik the right to continue to use the
                  Products as contemplated hereunder, or (ii) replace or modify
                  the Products to make the use and distribution of the Licensed
                  Products hereunder non-infringing. If neither option is
                  reasonably available to CRAY, this Agreement may be terminated
                  by either party at any time upon written notice subject to the
                  obligation of indemnification set forth above.

         8.3      CRAY shall have no liability for any claim of copyright
                  infringement or violation of proprietary rights to the extent
                  such claim is based on the use of the Products in a manner
                  other than is permitted under this Agreement or is based on a
                  modification of the Products by or for BioNumerik or a third
                  party, or any failure to implement any modification to the
                  Products supplied by CRAY.

         8.4      BioNumerik shall indemnify CRAY and hold CRAY harmless from
                  all damages and all reasonable expenditures incurred by CRAY
                  as the result of any charge or claim asserted against CRAY by
                  third parties resulting from BioNumerik's use of the results
                  of the use of the Products, other than any charge or claim of
                  copyright infringement or violation of proprietary rights, as
                  a result of BioNumerik's use of the Products hereunder,
                  provided that BioNumerik is given prompt notice of any such
                  claim and CRAY provides reasonable assistance to BioNumerik in
                  connection with such claims.

9.       Limitation of Liability.

         9.1      NEITHER PARTY SHALL BE LIABLE FOR ANY LOSS OR DAMAGE CAUSED BY
                  DELAY IN FURNISHING THE PRODUCTS OR SERVICES UNDER THIS
                  AGREEMENT, OR BY DELAY IN ANY OTHER PERFORMANCE UNDER OR
                  PURSUANT TO THIS AGREEMENT.

         9.2      IN NO EVENT WILL EITHER PARTY'S LIABILITY OF ANY KIND INCLUDE
                  ANY SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL LOSSES OR
                  DAMAGES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH POTENTIAL
                  LOSS OR DAMAGE



                                                             BETA TEST AGREEMENT
                                                                          PAGE 6

<PAGE>

10.      Term and Termination.

         10.1     This Agreement shall take effect as of the date first written
                  above and, unless earlier terminated as provided in Section
                  10.2 below, shall remain in effect for the initial Beta Test
                  Period of three (3) years after March 1, 2001. Thereafter,
                  this Agreement shall be automatically renewed for up to two
                  additional periods of one (1) year each, unless either party
                  shall have given notice to the other of its intention not to
                  renew not later than the date ninety (90) days prior to the
                  beginning of any renewal term of this Agreement.

         10.2     This Agreement may be terminated in accordance with the
                  following provisions:

                  (a)      Either party may terminate this Agreement by giving
                           notice in writing to the other party in the event the
                           other party is in breach of this Agreement and shall
                           have failed to cure such breach within thirty (30)
                           days of receipt of written notice thereof from the
                           first party.

                  (b)      Either party hereto may terminate this Agreement at
                           any time by giving notice in writing to the other
                           party, which notice shall be effective upon dispatch,
                           should the other party file a petition of any type as
                           to its bankruptcy, be declared bankrupt, become
                           insolvent, make an assignment for the benefit of
                           creditors, go into liquidation or receivership, or
                           otherwise lose legal control of its business, or
                           should the other party or a substantial part of its
                           business come under the control of a third party.

                  (c)      CRAY may terminate this Agreement upon sixty (60)
                           days notice if Dr. Hausheer terminates his
                           relationship with BioNumerik.

         10.3     Upon the termination of this Agreement, the parties shall have
                  the following rights and obligations:

                  (a)      The licenses granted to BioNumerik in this Agreement
                           shall terminate immediately, and BioNumerik shall
                           make the Products available to CRAY for
                           deinstallation and return and shall assist CRAY with
                           such deinstallation to the extent reasonably
                           necessary.

                  (b)      Each party shall promptly return to the other all
                           copies then in its possession of Confidential
                           Information provided by the other party.

                  (c)      The provisions of Sections 4, 7, 8, 9 and 11 of this
                           Agreement shall survive.


                                                             BETA TEST AGREEMENT
                                                                          PAGE 7

<PAGE>

11.      Confidentiality.

         11.1     A party receiving Confidential Information shall restrict the
                  use of the Confidential Information to those purposes
                  necessary for the exercise of the receiving party's rights, or
                  performance of the receiving party's obligations under this
                  Agreement. During the term of this Agreement and thereafter,
                  each party shall safeguard against disclosure of the
                  Confidential Information to third parties using the same
                  degree of care to prevent disclosure as it uses to protect its
                  own information of like importance, but at least reasonable
                  care. A party may make only the minimum number of copies of
                  any Confidential Information required to carry out the purpose
                  of this Agreement. All proprietary and copyright notices in
                  the original must be affixed to copies or partial copies.

         11.2     Neither party shall be obligated to maintain any information
                  in confidence or refrain from use if, (i) the information was
                  in the receiving party's possession or was known to it prior
                  to its receipt from the disclosing party, (ii) the information
                  is independently developed by the receiving party without the
                  utilization of Confidential Information of the disclosing
                  party, (iii) the information is or becomes public knowledge
                  without fault of the receiving party, (iv) the information is
                  or becomes available on an a nonconfidential basis to the
                  receiving party from a source other than the disclosing party,
                  (v) the information becomes available on a non-confidential
                  basis to a third party from the disclosing party or from
                  someone acting under its control, or (vi) the information is
                  publicly disclosed (i.e. not under adequate protective order)
                  by the receiving party under an order of a court or government
                  agency, provided that the receiving party provides prior
                  written notification to the disclosing party of such
                  obligation and the opportunity to oppose such order.

12.      General.

         12.1     This Agreement does not make either party the agent or legal
                  representative of the other for any purpose whatsoever.
                  Neither party is granted any right or authority to assume or
                  to create any obligation or responsibility, express or
                  implied, on behalf of or in the name of the other party. In
                  fulfilling its obligations pursuant to this Agreement, each
                  party shall be acting as an independent contractor.

         12.2     Neither party shall have the right to assign or otherwise
                  transfer its rights and obligations under this Agreement
                  except with the prior written consent of the other party. Any
                  prohibited assignment shall be null and void. Notwithstanding
                  the foregoing, subject to the provisions of Section 10.2(b)
                  either party may assign this Agreement without approval to an
                  entity that succeeds to all or substantially all of the
                  party's business or assets (by acquisition, merger or



                                                             BETA TEST AGREEMENT
                                                                          PAGE 8

<PAGE>

                  otherwise), so long as Dr. Frederick Hausheer remains in a
                  similar capacity with BioNumerik, its successors or assigns.

         12.3     Notices permitted or required to be given hereunder shall be
                  deemed sufficient if given by registered or certified mail,
                  postage prepaid, return receipt requested, addressed to the
                  respective addresses of each party as first above written or
                  at such other addresses as the respective parties may
                  designate by like notice from time to time. Notices shal1 be
                  effective upon the earlier to occur of (i) receipt by the
                  party to which notice is given, or (ii) the third (3rd)
                  business day following the date such notice was posted.

         12.4     This Agreement constitutes the entire agreement between the
                  parties with respect to the testing, evaluation and loan of
                  the Products and supersedes all previous agreements by and
                  between the parties related thereto, as well as all proposals,
                  oral or written, and all negotiations, conversations or
                  discussions held between the parties related to this
                  Agreement.

         12.5     This Agreement shall not be deemed or construed to be
                  modified, amended, rescinded or waived, in whole or in part,
                  except by written amendment signed by both parties.

         12.6     The terms of this Agreement are confidential and no party
                  shall issue press releases or engage in other types of
                  publicity of any nature dealing with the commercial and legal
                  details of this Agreement, or any information regarding the
                  performance of the products of the other party, without the
                  other party's prior written approval, which approval shall not
                  be unreasonably withheld. However, approval of such disclosure
                  shall be deemed to have been given to the extent such
                  disclosure is required to comply with governmental rules,
                  regulations or other governmental or legal requirements. In
                  such event, the publishing party shall furnish a copy of such
                  disclosure to the other party. Notwithstanding the foregoing,
                  BioNumerik shall retain the right to (i) demonstrate the
                  Products to third parties in accordance with the performance
                  of its obligations hereunder, and (ii) disclose the existence
                  of this Agreement in its informational material and the
                  material terms of this Agreement to its shareholders and
                  potential shareholders.

         12.7     In the event that any of the terms of this Agreement are in
                  conflict with any rule of law or statutory provision or
                  otherwise unenforceable under the laws or regulations of any
                  government or subdivision thereof, such terms shall be deemed
                  stricken from this Agreement, but such invalidity or
                  unenforceability shall not invalidate any of the other terms
                  of this Agreement and this Agreement shall continue in force,
                  unless the invalidity or unenforceability of any such
                  provisions of this Agreement does substantial violence to, or
                  where the invalid or unenforceable provisions comprise an
                  integral part of, or are otherwise inseparable from, the
                  remainder of this Agreement.


                                                             BETA TEST AGREEMENT
                                                                          PAGE 9

<PAGE>

         12.8     This Agreement may be executed in two or more counterparts and
                  each such counterpart shall be deemed an original of this
                  Agreement.

         12.9     No failure by either party to take any action or assert any
                  right hereunder shall be deemed to be a waiver of such right
                  in the event of the continuation or repetition of the
                  circumstances giving rise to such right.

         12.10    This Agreement shall be governed by, and interpreted and
                  construed in accordance with the laws of the State of
                  Washington.



BIONUMERIK PHARMACEUTICALS, INC.                  CRAY INC.


By: /s/ FREDERICK H. HAUSHEER, M.D.               By: /s/ JIM ROTTSOLK
Name:  Frederick H. Hausheer, M.D.                Name:  Jim Rottsolk

Title: Chief Executive Officer                    Title: Chief Executive Officer

Date:  June 27, 2001                              Date:  June 27, 2001



                                                             BETA TEST AGREEMENT
                                                                         PAGE 10

<PAGE>

                                    EXHIBIT A
                             EQUIPMENT AND SOFTWARE


[**]


[**] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.


                                                             BETA TEST AGREEMENT
                                                                         PAGE 11



<PAGE>

                                    EXHIBIT B

                                    PRODUCTS

Software Product
[**]



Cray Datacenter Systems

[**]

For purposes of this agreement, an hour of CPU time is measured as one CPU hour
of [**] time. CPU time on other systems is measured relative to a Cray [**]
based on the theoretical peak performance (the number of CPUs or Processing
Elements (PE's) employed times the theoretical peak performance of a single CPU
or PE) of the other system.

[**]



                                                             BETA TEST AGREEMENT
                                                                         PAGE 12

<PAGE>


[**] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.


                                                             BETA TEST AGREEMENT
                                                                         PAGE 13

<PAGE>

                                    EXHIBIT C

I.       Ongoing Obligations

         BioNumerik shall provide specific feedback to Cray Inc. with respect to
         [**]

II.      Annual Obligations [**]

III.     Additional Obligations  [**]



                                                             BETA TEST AGREEMENT
                                                                         PAGE 14

<PAGE>

[**] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.



                                                             BETA TEST AGREEMENT
                                                                         PAGE 15

<PAGE>

                                    EXHIBIT D

                               PRINCIPAL CONTACTS

The BioNumerik Principal Contact shall be [**], and [**] and [**] shall act as
alternate Principal Contacts.

The Cray Inc. Principal Contact shall be:

1.       With respect to the technical aspects of the relationship established
         in this Agreement, [**] or his subsequent designee.

2.       With respect to marketing aspects of the relationship established in
         this Agreement, [**] or his subsequent designee.

3.       With respect to the general terms of the relationship established in
         this Agreement, [**].

Cray Inc. shall reimburse BioNumerik for all reasonable out-of-pocket expenses
of the BioNumerik Principal Contact in satisfying BioNumerik's obligations under
this Agreement, including, but not limited to travel, lodging, meals, and a
negotiated per diem. All services provided by the BioNumerik Point of Contact
under this Agreement will be subject to the obligations of the BioNumerik Point
of Contact to BioNumerik, and Cray Inc. will cooperate with the BioNumerik Point
of Contact to avoid any interference with the operation of BioNumerik.



                                                             BETA TEST AGREEMENT
                                                                         PAGE 16

<PAGE>


[**] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.



                                                             BETA TEST AGREEMENT
                                                                         PAGE 17