<PAGE>

                                                                   EXHIBIT 10.46

                                                                    CONFIDENTIAL



               COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT


                                    between


                      3-DIMENSIONAL PHARMACEUTICALS, INC.


                                      and


                                ATHERSYS, INC.


NOTE:    Certain portions of this Collaborative Research and Development
----
Agreement and its exhibits, which are identified by the symbol "[* *]", have
been omitted and filed separately with the Securities and Exchange Commission
pursuant to a confidential treatment request.
<PAGE>

ARTICLE 1      DEFINITIONS.....................................................1

ARTICLE 2      JOINT COMMITTEES...............................................10

     2.1    Joint Steering Committee..........................................10

     2.2    Chairperson.......................................................10

     2.3    Joint Development Committee.......................................11

     2.4    Responsibilities of the Joint Committees..........................11

     2.5    Voting............................................................12

     2.6    Opinion of Patent Counsel.........................................12

ARTICLE 3      RESEARCH PROGRAM...............................................12

     3.1    Goal of Research Program..........................................12

     3.2    Selection of Athersys Target and 3DP Target.......................12

     3.3    Rejection.........................................................13

     3.4    Selection/Rejection of Joint Targets..............................13

     3.5    Athersys Responsibilities.........................................13

     3.6    3DP Responsibilities..............................................14

     3.7    Completion of Lead Generation.....................................14

     3.8    Additional Efforts................................................14

     3.9    Termination of Research Program For a Joint Target................15

     3.10   Optional 3DP Continued Research...................................15

     3.11   Re-instatement of Terminated Joint Target.........................15

     3.12   [*                        *]......................................16

     3.13   Expansion of Research Program.....................................16

ARTICLE 4      DEVELOPMENT PROGRAM............................................17

     4.1    Goal of Development Program; Development Plans....................17

     4.2    Responsibilities During the Development Program...................17

     4.3    Determination to Move from Lead Generation to Lead Optimization...17

     4.4    Progression into Lead Optimization................................18

     4.5    Athersys Responsibilities.........................................18

     4.6    3DP Responsibilities..............................................18

     4.7    Progression into Pre-Clinical Development and Clinical
            Development.......................................................18

     4.8    Development Efforts...............................................18

     4.9    Opting Out........................................................18

                                       i
<PAGE>

     4.10   Termination of Development Program for a Joint Compound...........19

ARTICLE 5      COMMERCIALIZATION..............................................20

     5.1    Commercialization of Joint Products...............................20

     5.2    Division of Revenues for Joint Products...........................20

     5.3    Athersys Product Commercialization................................21

     5.4    3DP Product Commercialization.....................................22

ARTICLE 6      EXCLUSIVITY....................................................23

     6.1    Athersys Restriction..............................................23

     6.2    3DP Restriction...................................................23

ARTICLE 7      COSTS AND FINANCIAL RECORD KEEPING.............................23

     7.1    Research Program Costs............................................23

     7.2    Development Program Costs.........................................23

     7.3    Record Keeping....................................................24

     7.4    Quarterly Reconciliation..........................................24

     7.5    Audits............................................................25

ARTICLE 8      CROSS-LICENSES.................................................25

     8.1    License Grant by 3DP..............................................25

     8.2    License Grant by Athersys.........................................26

     8.3    3DP's Libraries...................................................26

ARTICLE 9      RESEARCH PROGRAM AND DEVELOPMENT PROGRAM RECORD KEEPING........26

     9.1    Laboratory Notebooks..............................................27

     9.2    Audit.............................................................27

     9.3    Policies for Maintaining Records; Assignments of Inventions.......27

ARTICLE 10     CONFIDENTIAL INFORMATION.......................................27

     10.1   Confidentiality Obligations.......................................27

     10.2   Written Assurances and Permitted Uses of Confidential
            Information.......................................................28

                                       ii
<PAGE>

     10.3   Publication.......................................................28

     10.4   Permitted Disclosures.............................................29

ARTICLE 11     PATENTS AND INTELLECTUAL PROPERTY..............................30

     11.1   Ownership; Inventions.............................................30

     11.2   Prosecution and Maintenance of Patent Rights......................32

     11.3   Prosecution and Maintenance of Joint Targets, Joint Lead
            Compounds, Joint Safety Assessment Compounds and Joint
            Development Compounds.............................................32

     11.4   Cooperation.......................................................33

     11.5   Third Party Infringement..........................................33

     11.6   Other Intellectual Property Infringement..........................34

     11.7   Patent Term Extensions............................................35

ARTICLE 12     REPRESENTATIONS AND WARRANTIES.................................35

     12.1   Authority.........................................................35

     12.2   Commercially Reasonable Efforts...................................35

     12.3   No Conflicts......................................................35

     12.4   No Existing Third Party Rights....................................35

     12.5   Intellectual Property.............................................35

     12.6   Access to Athersys Cell Lines.....................................36

     12.7   Access to 3DP Compounds...........................................36

     12.8   Disclaimer of Warranties..........................................37

ARTICLE 13     INDEMNIFICATION................................................37

     13.1   Indemnification by Athersys.......................................37

     13.2   Indemnification By 3DP............................................38

     13.3   Insurance Proceeds................................................38

     13.4   Insurance.........................................................38

ARTICLE 14     TERM AND TERMINATION...........................................38

     14.1   Term..............................................................38

     14.2   Extension of Research Program.....................................39

     14.3   Partial Termination...............................................39

     14.4   Breach............................................................39

     14.5   Insolvency or Bankruptcy..........................................39

     14.6   Survival of Obligations...........................................40

     14.7   Effects of Termination............................................40

                                      iii
<PAGE>

ARTICLE 15     DISPUTE RESOLUTION.............................................41

     15.1   Dispute Resolution Process........................................41

     15.2   Dispute Resolution Panel..........................................41

     15.3   Arbitration.......................................................41

ARTICLE 16     MISCELLANEOUS PROVISIONS.......................................42

     16.1   Entire Agreement..................................................42

     16.2   Further Actions...................................................42

     16.3   Binding Effect....................................................42

     16.4   Assignment........................................................42

     16.5   No Implied Licenses...............................................42

     16.6   No Waiver.........................................................42

     16.7   Force Majeure.....................................................42

     16.8   Independent Contractors...........................................42

     16.9   Notices and Deliveries............................................43

     16.10  Public Announcements..............................................43

     16.11  Headings..........................................................44

     16.12  Severability......................................................44

     16.13  No Consequential Damages..........................................44

     16.14  Applicable Law....................................................44

     16.15  Counterparts......................................................44

                                       iv
<PAGE>

                COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
                ------------------------------------------------

         This Agreement, made as of the 25th day of October, 2001 (the
"Effective Date"), between 3-Dimensional Pharmaceuticals, Inc., a corporation
 --------------
organized under the laws of Delaware and having a place of business at 1020
Stony Hill Road, Suite 300, Yardley, Pennsylvania 19067 (herein referred to as
"3DP") and Athersys, Inc., a corporation organized under the laws of Delaware
 ---
and having a place of business at 3201 Carnegie Avenue, Cleveland, Ohio 44115
(herein referred to as "Athersys") (3DP and Athersys are each referred to as a
                        --------
"Party" and collectively, the "Parties").
                               -------

                               WITNESSETH THAT:

         WHEREAS, 3DP is engaged in drug discovery research for a variety of
pharmacologically active compounds and the development of technologies to
facilitate such research and 3DP has patented and other proprietary systems for
generating chemical compounds having desired pharmaceutical properties including
DiscoverWorks(TM) Technology;

         WHEREAS, Athersys is engaged in discovery and production of drug
discovery targets and drug discovery screens and has proprietary technologies
therefor, including RAGE-VT Technology and RAGE-PE Technology; and

         WHEREAS, the Parties wish to enter into a strategic alliance in which
they will collaborate on the selection of drug discovery targets to be produced
and developed into screens by Athersys, on the screening by Athersys of
compounds to be selected or synthesized and provided by 3DP, and on the further
research and development and commercialization of compounds that are shown to be
active in such screens.

         NOW, THEREFORE, in consideration of the covenants and obligations
expressed herein, and intending to be legally bound, and otherwise to be bound
by proper and reasonable conduct, the Parties agree as follows:

                                    ARTICLE 1
                                   DEFINITIONS

         1.1   "Affiliate" means, with respect to any Party, any corporation or
                ---------
other business entity, which controls, is controlled by, or is under common
control with such Party. A corporation or other entity shall be regarded as in
control of another corporation or entity if it owns or directly or indirectly
controls at least fifty (50%) of the voting stock or other ownership interest of
the other corporation or entity (or alternatively with respect to foreign
entities, if it owns the maximum such ownership interest permitted by law), or
if it possesses, directly or indirectly, the power to direct or cause the
direction of the management and policies of the corporation or other entity or
the power to elect or appoint at least fifty (50%) of the members of the
governing body of the corporation or other entity.

         1.2   "Athersys" means Athersys and its Affiliates.
                --------
<PAGE>

         1.3   "Athersys Compound" means a Compound that is selected or
                -----------------
otherwise results from screening against the Athersys Target during Lead
Generation.

         1.4   "Athersys Development Compound" means a Development Compound
                -----------------------------
directed against an Athersys Target that results from Pre-Clinical Development
undertaken by Athersys and has been selected for Clinical Development.

         1.5   "Athersys Indemnitees" shall have the meaning set forth in
                --------------------
Section 13.2.

         1.6   "Athersys Lead Compound" means a Lead Compound directed against
                ----------------------
an Athersys Target that results from Lead Generation and has been selected for
Lead Optimization or is identified during Lead Optimization.

         1.7   "Athersys Product" means a Product that comprises an Athersys
                ----------------
Development Compound.

         1.8   "Athersys Safety Assessment Compound" means a Safety Assessment
                -----------------------------------
Compound directed against an Athersys Target that results from Lead Optimization
undertaken by Athersys and has been selected for Pre-Clinical Development.

         1.9   "Athersys Target" means the Target that is selected by Athersys
                ---------------
for screening of Compounds provided by 3DP during Lead Generation under this
Agreement to develop a Product that will be owned exclusively by Athersys.

         1.10  "Candidate Target" means a Target listed in Schedule 1.10,
                ----------------                           -------------
Targets that are relevant to the disease areas listed in Schedule 1.10,
                                                         -------------
and Targets that are within the families of Targets listed in Schedule 1.10,
                                                              -------------
as may be amended by the JSC from time to time.

         1.11  "Clinical Development" means the full range of Phase I, Phase II
                --------------------
and Phase III clinical development that are required to obtain a Regulatory
Approval to market a Product.

         1.12  "Clinical Development Plan" means the detailed program of
                -------------------------
Clinical Development activities documented by the JDC for each Joint Target and
its respective Joint Development Compound and including those elements described
in Section 4.1.

         1.13  "Combination Product" means a Product that includes one or more
                -------------------
active ingredients in addition to a Development Compound developed under this
Agreement.

         1.14  "Compound" means an organic chemical compound that is selected or
                --------
synthesized by 3DP from the 3DP Probe Library or associated 3DP Synthetically
Accessible Libraries or from other sources owned or controlled by 3DP for use in
the Research Program. A flowchart of the potential progression of a Compound
through Pre-Clinical Development and Clinical Development and into a Product is
attached hereto as Schedule 1.14.
                   -------------

         1.15  "Confidential Information" means all proprietary, non-public
                ------------------------
information that has or could have commercial value or other utility in a
Party's business, or the unauthorized disclosure of which could be detrimental
to the Party's interests, including confidential information, inventions,
know-how, data and materials relating to chemical structures, Targets,

                                       2
<PAGE>

screens, assays, utility against Targets, Compounds, Lead Compounds, Safety
Assessment Compounds, Development Compounds or Products provided by the Parties
or otherwise developed under this Agreement, and shall include, without
limitation, research, technical, development, manufacturing, commercialization,
financial, personnel and other business information and plans, whether in oral,
written, graphic or electronic form.

         1.16  "Development Compound" means a Safety Assessment Compound that
                --------------------
results from Pre-Clinical Development and has characteristics considered
required for a successful IND submission and, therefore, suitable for and has
been selected for Clinical Development.

         1.17  "Development Plan" means a Lead Optimization Plan, Pre-Clinical
                ----------------
Development Plan or Clinical Development Plan.

         1.18  "Development Program" means the activities and tasks that
                -------------------
comprise Lead Optimization, Pre-Clinical Development, Clinical Development,
manufacture and registration of a Product as applied to Joint Lead Compounds,
Joint Safety Assessment Compounds, Joint Development Compounds and Joint
Products as outlined in ARTICLE 4. Schedule 1.14 graphically depicts the
                                   -------------
elements of the Development Program and its relationship to the Research
Program.

         1.19  "Development Term" means with respect to each Lead Compound, the
                ----------------
period of time beginning with selection of such Lead Compound for Lead
Optimization and ending with the earlier of (i) termination by the JSC or the
JDC, as applicable, of the Development Program for such Lead Compound or Safety
Assessment Compounds or Development Compounds derived therefrom, and (ii) the
first commercial sale of a Product that results from such Lead Compound or
Safety Assessment Compound or Development Compound derived therefrom.

         1.20  "Disclosing Party" shall have the meaning set forth in Section
                ----------------
10.1.

         1.21  "Discontinuing Party" means a Party that elects to opt out of
                -------------------
further development and funding of a Joint Lead Compound, Joint Safety
Assessment Compound or Joint Development Compound, as further provided in
Section 4.9.

         1.22  "DiscoverWorks(TM) Technology" means 3DP's full panoply of drug
                ----------------------------
discovery and compound and library synthesis technologies including but not
limited to DirectedDiversity(R) technology, ThermoFluor(R) Technology, 3DP Probe
Libraries, 3DP Synthetically Accessible Libraries and Proteomica(TM) technology,
notwithstanding that not all such technologies and resources will be utilized
under this Agreement.

         1.23  "Effective Date" shall have the meaning set forth in the
                --------------
preamble.

         1.24  "FTE" means a full time equivalent scientific employee (i.e., one
                ---
full-time or multiple part-time employees aggregating to one full-time employee)
employed by a Party and assigned to work on the Research Program or Development
Program with such time and effort to constitute one employee working on the
Research Program or Development Program on a full-time basis consistent with
normal business and scientific practice (i.e., on an annual basis, at

                                       3
<PAGE>

least forty (40) hours per week of dedicated effort for at least forty-eight
(48) weeks per year). In no event does an FTE include a subcontractor.

         1.25  "FTE Rate" means [* *] per year per FTE for the first contract
                --------
year subject to an annual increase of [* *] compounded annually thereafter to
reflect inflation.

         1.26  "Funding Party" means a Party that elects to continue development
                -------------
of a Joint Lead Compound, Joint Safety Assessment Compound or Joint Development
Compound as further provided in Section 4.9 after the other Party opts out of
further development, i.e., becomes a Discontinuing Party.
                     ----

         1.27  "IND" means (a) (i) an Investigational New Drug Application, as
                ---
defined in the U.S. Federal Food, Drug and Cosmetic Act, as amended, and the
regulations promulgated thereunder, that is required to be filed with the FDA
before beginning clinical testing of a Development Compound in human subjects,
or any successor application or procedure and (ii) any foreign counterpart of a
U.S. Investigational New Drug Application, and (b) all supplements and
amendments that may be filed with respect to the foregoing.

         1.28  "Intellectual Property" means all of the following or their
                ---------------------
substantial equivalent or counterpart in any jurisdiction throughout the world:
(i) patents, patent applications and patent disclosures, (ii) trademarks,
service marks, trade dress, trade names, corporate names, logos and Internet
domain names, (iii) copyrights and copyrightable works, (iv) registrations and
applications for any registration for any of the foregoing and (v) trade
secrets, confidential information and inventions.

         1.29  "Iterative Chemistry Limitations" means limitations inherent in
                -------------------------------
synthesizing compounds through iterative rounds of chemistry using combinatorial
chemistry reaction schemes as developed for the 3DP Synthetically Accessible
Library. A further explanation and examples of such iterative chemistry
limitations are provided in Schedule 1.29.
                            -------------

         1.30  "Joint Compound" means a Compound that is selected or otherwise
                --------------
results from screening against a Joint Target during Lead Generation.

         1.31  "Joint Development Compound" means a Development Compound
                --------------------------
directed against a Joint Target that results from Pre-Clinical Development
undertaken by the Parties and has been selected by the JDC for Clinical
Development.

         1.32  "Joint Lead Compound" means a Lead Compound directed against a
                -------------------
Joint Target that results from Lead Generation and has been selected by the JSC
for Lead Optimization.

         1.33  "Joint Product" means a Product that comprises a Joint
                -------------
Development Compound.

         1.34  "Joint Safety Assessment Compound" means a Safety Assessment
                --------------------------------
Compound directed against a Joint Target that results from Lead Optimization
undertaken by the Parties and has been selected by the JSC for Pre-Clinical
Development.

                                       4
<PAGE>


         1.35  "Joint Target" means one of the [*  *] Targets that are selected
                ------------
by the JSC in accordance with Section 3.4 for screening by Athersys of Compounds
provided by 3DP under this Agreement to develop a Product that will be owned
jointly by Athersys and 3DP.

         1.36  "JDC" means the Joint Development Committee established as
                ---
provided in Section 2.3. Schedule 1.14 graphically depicts the relation of the
                         -------------
JDC and the JSC to the Research and Development Program activities.

         1.37  "JSC" means the Joint Steering Committee established as provided
                ---
in Section 2.1.

         1.38  "Lead Compound" means a Compound that has a well-understood
                -------------
structure-activity relationship with respect to a Target and is suitable for
Lead Optimization, such that derivatives of the Compound, e.g., homologs,
                                                          ----
analogs, polymorphs and isomers, can be designed which would reasonably be
expected to have greater Potency, selectivity, pharmacokinetics,
pharmacodynamics and acute safety. "Lead Compound" also includes such
derivatives, e.g., homologs, analogs, polymorphs, and isomers up to the point of
             ----
selection as a Safety Assessment Compound.

         1.39  "Lead Generation" means a program of identifying Lead Compounds
                ---------------
by using Primary Screens and Secondary Screens to screen Compounds from the 3DP
Probe Library and using up to three rounds of 3DP's proprietary iterative
combinatorial chemical synthesis developed from the 3DP Synthetically Accessible
Library, and DirectedDiversity(R) Technology to identify Compounds or classes of
Compounds having superior activity and by using Secondary Screens to assist 3DP
in determining the structure-activity relationships of Compounds being screened
and confirm cell-based functional activity of the Compounds.

         1.40  "Lead Generation Plan" means the detailed program of Lead
                --------------------
Generation activities as documented by the JSC for each Joint Target and
including those elements described in Section 2.4.1.

         1.41  "Lead Optimization" means a program of activities to progress
                -----------------
Lead Compounds into Safety Assessment Compounds by using customized or novel
medicinal chemistry technologies to make specific derivatives, e.g., homologs,
                                                               ----
analogs, polymorphs and isomers, of Lead Compounds and testing such derivatives
in in vitro, ex vivo assays and/or in vivo animal models and using the data
therefrom to improve Lead Compounds' structure-activity relationships, Potency,
selectivity, pharmacokinetics, pharmacodynamics and acute safety. It is
understood that Lead Optimization and Pre-Clinical Development overlap in the
sense that certain data developed during Lead Optimization are useful in
Pre-Clinical Development.

         1.42  "Lead Optimization Plan" means the detailed program of Lead
                ----------------------
Optimization activities as documented by the JSC for each Joint Target and its
respective Joint Lead Compound and including those elements described in Section
4.1.

         1.43  "LMP" means license fees, milestone payments, purchase price or
                ---
the fair market value of non-cash consideration received from a Third Party in
exchange for a right or license granted, or the sale or assignment of rights, by
Athersys in an Athersys Lead Compound, Athersys Safety Assessment Compound,
Athersys Development Compound and/or Athersys

                                       5
<PAGE>

Product or by 3DP in a 3DP Lead Compound, 3DP Safety Assessment Compound, 3DP
Development Compound and/or 3DP Product, as the case may be. LMP shall not
include consideration received for services provided to the Third Party and
shall also not include royalties received on Net Sales made by such Third Party.

         1.44  "NDA" means (a) (i) a New Drug Application pursuant to 21 U.S.C.
                ---
Section 505(b)(1) submitted to the FDA or any successor application or procedure
and (ii) any foreign counterpart of a U.S. New Drug Application, and (b) all
supplements and amendments, including supplemental New Drug Applications (and
any foreign counterparts), that may be filed with respect to the foregoing.

         1.45  "Net Sales" means the gross amount invoiced for sale of a Product
                ---------
in the Territory by a Party or any of its Affiliates, licensees or sublicensees,
to a Third Party end user, including but not limited to distributors, in bona
fide, arm's-length transactions, after deduction of the following items (to the
extent actually incurred or reasonably estimated and accrued and to the extent
not already deducted in the amount invoiced): (i) customary trade, quantity and
cash discounts, wholesaler-charge backs, or rebates (including, but not limited
to, rebates to governmental agencies, managed care organizations, health
management organizations, pharmacy benefit managers and group purchasing
organizations); (ii) customary credits or allowances for rejection or return of
previously sold Products; (iii) excise, sales and other consumption taxes and
customs duties; (iv) retroactive price reductions including but not limited to
those imposed by governmental agencies; and (iv) any charge for freight or
insurance if separately stated on the same invoice as for the sale of Product
and directly related to the sale or distribution of the Product. A "sale" of a
Product is deemed to occur upon the invoicing, or if no invoice is issued, upon
the earlier of shipment or transfer of title in the Product to a Third Party.

         In the event that all the active ingredients of a Combination Product
are also sold separately and in identical strengths to those contained in the
Combination Product, then Net Sales shall be calculated as set forth above on
the basis of the gross invoice price of a Product containing the same weight of
the active ingredient in the Athersys Product, the 3DP Product or the Joint
Products, as the case may be, sold independently [ A ] divided by the sum of the
gross invoice price of each of the active ingredients contained in the
Combination Product sold independently [ B + A ], multiplied by the gross
invoice price of the Combination Product, as shown by the following formula:

         Net Sales =     [ A ]       x [gross sales of the Combination Product]
                     --------------
                       [ B + A ]

         In the event that the Athersys Product, the 3DP Product or the Joint
Products, as the case may be, and/or any of the other active ingredients of a
Combination Product are not sold separately in identical strengths to those
contained in the Combination Product, then the Parties agree to negotiate in
good faith the calculation of Net Sales with regard to such Combination Product
based upon the relative value of the active ingredients as determined by the
Parties hereto in good faith.

                                       6
<PAGE>

         Sales between or among a Party and its Affiliates, licensees or
sublicensees shall not be used to calculate Net Sales unless the purchasing
Affiliate, licensee or sublicensee is an end-user.

         Net Sales for purposes of Sections 5.2, 5.3 and 5.4 includes sales by
Third Party assignees or Third Party purchasers of a Party's rights thereunder.

         1.46  "Non-publishing Party" shall have the meaning set forth in
                --------------------
Section 10.3.2.

         1.47  "Opt-Out Point" shall have the meaning set forth in Section 14.3.
                -------------

         1.48  "Party" and/or "Parties" shall have the meaning set forth in the
                -----          -------
preamble hereto.

         1.49  "Patent Prosecution" shall have the meaning set forth in Section
                ------------------
11.2.

         1.50  "Patent Rights" means all existing patents and patent
                -------------
applications and all patent applications hereafter filed, including any
continuations, continuations-in-part, divisions, provisionals or any substitute
applications, any patent issued with respect to any such patent applications,
any reissue, reexamination, renewal or extension (including any supplemental
patent certificate) of any such patent, and any confirmation patent or
registration patent or patent of addition based on any such patent, and all
foreign counterparts of any of the foregoing.

         1.51  "Phase I" means a complete program of one or more human clinical
                -------
trials in any country that is intended to initially evaluate the safety and/or
pharmacological effect of a Product in subjects or that would otherwise satisfy
the requirements of 21 CFR 312.21(a), or its foreign equivalent.

         1.52  "Phase II" means a complete program of one or more human clinical
                --------
trials in any country that is intended to initially evaluate the effectiveness
of a Product for a particular indication or indications in patients with the
disease or indication under study or that would otherwise satisfy the
requirements of 21 CFR 312.21(b), or its foreign equivalent.

         1.53  "Phase III" means a complete program of one or more pivotal human
                ---------
clinical trials in any country the results of which could be used to establish
safety and efficacy of a Product as a basis for a Biologics License Application,
Product License Application, NDA or similar application for marketing approval
of a Product or that would otherwise satisfy the requirements of 21 CFR
312.21(c), or its foreign equivalent.

         1.54  "Phase IV" means a program of one or more human clinical trials
                --------
in any country after approval for marketing in that country, including a trial
that begins before approval but concludes after approval.

         1.55  "Potency" means the level of activity against a Target at a given
                -------
molar concentration. A Compound is more potent than another Compound if it has a
higher level of activity at the same or lower molar concentration or if it has
the same or a higher level of activity at a lower molar concentration.

                                       7
<PAGE>

         1.56  "Pre-Clinical Development" means a program of developing Safety
                ------------------------
Assessment Compounds into Development Compounds by undertaking the full range of
pre-clinical studies, and the full range of safety and pathology/toxicology
studies required to file an IND including but not limited to drug metabolism,
pharmacokinetics, Potency, selectivity, and safety/toxicology studies.

         1.57  "Pre-Clinical Development Plan" means the detailed program of
                -----------------------------
Pre-Clinical Development activities, as documented by the JDC for each Joint
Target and its respective Joint Safety Assessment Compound and including those
elements described in Section 4.1.

         1.58  "Primary Screen" means a fluorometric, cell-based assay useful to
                --------------
screen Compounds for activity against Targets.

         1.59  "Program Compound" means a Compound, a Lead Compound, a Safety
                ----------------
Assessment Compound and/or a Development Compound.

         1.60  "Product" means any commercial product comprising an Athersys
                -------
Development Compound, a 3DP Development Compound or a Joint Development Compound
as an active ingredient.

         1.61  "Profits" means the amount, on an annual basis, equal to Net
                -------
Sales by a Party less any costs directly associated with such Net Sales,
including, but not limited to, costs of goods sold, selling and marketing
expenses, Phase IV expenses and royalties on Net Sales paid to the other Party
and to Third Parties to the extent applicable. Net Sales for the purpose of this
definition specifically exclude such Net Sales by a licensee or sublicensee.

         1.62  "Publication Plan" shall have the meaning set forth in Section
                ----------------
10.3.1.

         1.63  "Publishing Party" shall have the meaning set forth in Section
                ----------------
10.3.2.

         1.64  "RAGE-PE Technology" means Athersys' proprietary methods for
                ------------------
creation of protein expression libraries using Athersys' Random Activation of
Gene Expression(TM) technology.

         1.65  "RAGE-VT Technology" means Athersys' proprietary methods for
                ------------------
creation and isolation of human cell lines expressing validated drug targets of
interest using Athersys' Random Activation of Gene Expression(TM) technology.

         1.66  "Receiving Party" shall have the meaning set forth in Section
                ---------------
10.1.

         1.67  "Regulatory Approval" means any and all approvals (including any
                -------------------
applicable governmental price and reimbursement approvals), licenses,
registrations, or authorizations of any federal, national, multinational, state,
provincial or local regulatory agency, department, bureau or other governmental
entity necessary for the manufacture, use, storage, import, transport,
promotion, marketing and sale of a Product in a country.

                                       8
<PAGE>

         1.68  "Research Program" means the drug discovery program that
                ----------------
comprises selection of Joint Targets, the Athersys Target and the 3DP Target,
Screen Development and Lead Generation, and associated activities and tasks as
outlined in ARTICLE 3.

         1.69  "Research Program Costs" shall have the meaning set forth in
                ----------------------
Section 7.1.

         1.70  "Research Term" means, with respect to each of the Joint Targets,
                -------------
the 3DP Target or the Athersys Target, the period beginning on the Effective
Date and ending [* *] after the initiation of Lead Generation, unless this [* *]
period is (i) extended in whole or in part by mutual written agreement of the
Parties as set forth in Section 14.2 or (ii) terminated earlier pursuant to
Section 2.4.5.

         1.71  "Royalty Term" means, with respect to each of the Athersys
                ------------
Product, the 3DP Product, and the Joint Products and on a country-by-country
basis, the period of time beginning on the date of the first commercial sale of
such product and ending on the later of (a) when all claims of a patent covering
such Product are expired or rendered invalid or unenforceable and (b) ten (10)
years from the date of such first commercial sale in such country.

         1.72  "Safety Assessment Compound" means a Lead Compound that has
                --------------------------
undergone Lead Optimization and has adequate Potency, efficacy, selectivity,
pharmacokinetic/pharmacodynamic properties, and acute safety profile that is
suitable for Pre-Clinical Development and has been selected for Pre-Clinical
Development.

         1.73  "Screen Development" means a program of developing a Primary
                ------------------
Screen by selecting Targets using Athersys' proprietary gene expression
technology, RAGE-VT Technology, to express Targets in cell lines and developing
screens to identify Compounds that are active against Targets.

         1.74  "Secondary Screen" means a single, confirmatory cell-based assay
                ----------------
for a Target to determine or confirm function in a cell-based assay and to
assist in determining structure-activity relationships for each Target.

         1.75  "Small Molecule" means a non-peptidic, organic compound with a
                --------------
molecular weight of less than [*  *] daltons.

         1.76  "Target" means a human drug discovery target that is a G
                ------
Protein-coupled Receptor or an ion channel and human cell lines expressing such
receptor or ion channel.

         1.77  "Territory" means the entire world.
                ---------

         1.78  "ThermoFluor(R) Technology" means the Patent Rights of 3DP and
                -------------------------
associated proprietary 3DP know-how and instruments used to evaluate
ligand-binding parameters.

         1.79  "Third Party" means a person or party other than 3DP and Athersys
                -----------
or their Affiliates.

         1.80  "3DP" means 3DP and its Affiliates.
                ---

                                       9
<PAGE>

         1.81  "3DP Compound" means a Compound that is selected or otherwise
                ------------
results from screening against the 3DP Target during Lead Generation.

         1.82  "3DP Development Compound" means a Development Compound directed
                ------------------------
against a 3DP Target that results from Pre-Clinical Development undertaken by
3DP and has been selected for Clinical Development.

         1.83  "3DP Indemnitees" shall have the meaning set forth in Section
                ---------------
13.1.

         1.84  "3DP Lead Compound" means a Lead Compound directed against a 3DP
                -----------------
Target that results from Lead Generation and has been selected for Lead
Optimization.

         1.85  "3DP Probe Library" means 3DP's proprietary chemical library of
                -----------------
Small Molecules, synthesized by 3DP for the purpose of screening to find Lead
Compounds, of approximately [* *] diverse synthesized compounds in existence as
of the Effective Date.

         1.86  "3DP Product" means a Product that comprises a 3DP Development
                -----------
Compound.

         1.87  "3DP Safety Assessment Compound" means a Safety Assessment
                ------------------------------
Compound directed against a 3DP Target that results from Lead Optimization
undertaken by 3DP and has been selected for Pre-Clinical Development.

         1.88  "3DP Synthetically Accessible Library" means 3DP's proprietary
                ------------------------------------
Small Molecule compound library of approximately [* *] compounds available for
on-demand synthesis.

         1.89  "3DP Target" means the Target that is selected by 3DP for
                ----------
screening by Athersys of Compounds provided by 3DP under this Agreement to
develop a Product that will be owned exclusively by 3DP.

                                   ARTICLE 2
                                JOINT COMMITTEES

         2.1   Joint Steering Committee. Promptly following the Effective Date,
               ------------------------
the Parties shall establish a Joint Steering Committee ("JSC") that will be
                                                         ---
staffed by an equal number of 3DP and Athersys appointees. The total number of
JSC members will be six (6), but the number may be adjusted upward or downward
by the JSC from time to time provided the number of 3DP appointees is always the
same as the number of Athersys appointees. Each Party may replace any of one or
more of its appointees at will by giving written notice thereof to the other
Party.

         2.2   Chairperson. The Chairperson shall be selected initially by 3DP
               -----------
from among the 3DP appointees and shall serve in such role for six (6) months.
After such six (6) month period, Athersys shall designate the Chairperson from
among the Athersys appointees, and such person shall serve in such role for six
(6) months. Thereafter, 3DP and Athersys shall continue to alternate designation
of the Chairperson from their respective appointees every six (6) months
throughout the Research Term. The Chairperson will be responsible for calling
and chairing

                                       10
<PAGE>

meetings, developing meeting agendas, and recording meeting minutes and
decisions taken. The Chairperson shall call at least one meeting every three (3)
months during the Research Term.

         2.3   Joint Development Committee. Promptly after the JSC selects the
               ---------------------------
first Joint Safety Assessment Compound to progress into Pre-Clinical
Development, the Parties will establish a Joint Development Committee (the
"JDC") with a structure and governance as outlined for the JSC under Sections
 ---
2.1 and 2.2. In contrast to the JSC, however, the JDC will govern the
Pre-Clinical Development and Clinical Development. The JDC will review, approve,
and oversee the implementation of the Pre-Clinical Development Plans and
Clinical Development Plans. Schedule 1.14 graphically depicts the relation of
                            -------------
the JDC and the JSC to the Research Program and Development Program activities.

         2.4   Responsibilities of the Joint Committees.
               ----------------------------------------

               2.4.1  In general, the responsibilities of the JSC, will be to
adopt, review, and amend Lead Generation Plans, as described below, and Lead
Optimization Plans, as described in Section 4.1, and oversee and, whenever
practicable, expedite the implementation of such plans. Each Lead Generation
Plan shall contain, as early as possible before or during the Lead Generation
process, guidelines or criteria for determining whether a Compound constitutes a
Lead Compound, such guidelines or criteria to be amended thereafter with
increasing specificity during Lead Generation activities as practical. The JSC
will appoint Compounds that successfully complete Lead Generation as Joint Lead
Compounds and appoint Joint Lead Compounds that successfully complete Lead
Optimization as Joint Safety Assessment Compounds.

               2.4.2  The JSC shall be responsible for selecting the Joint
Targets and for approving the Primary Screens and Secondary Screens developed by
Athersys using the Joint Targets. If the JSC reasonably determines that a
Primary Screen or a Secondary Screen is unlikely to yield a Lead Compound, then
the JSC shall direct Athersys to terminate further efforts directed to such
screen(s). If the JSC terminates a screening effort directed to a Joint Target,
subject to there being sufficient time remaining in the Research Term, Athersys
shall attempt to develop a replacement screen using its existing capabilities on
the same Target.

               2.4.3  In general, the responsibilities of the JDC will be to
adopt, review, and amend Pre-Clinical Development Plans and Development Plans,
as described in Section 4.1, and oversee and, whenever practicable, expedite the
implementation of such plans. The JDC will appoint Joint Safety Assessment
Compounds that successfully complete Pre-Clinical Development as Joint
Development Compounds.

               2.4.4  The JDC shall be responsible for determining whether or
not and to what extent to pursue back-up Joint Safety Assessment Compounds and
back-up Joint Development Compounds.

               2.4.5  If (i) at any time the JSC or the JDC, as the case may be,
determines that further research using a Joint Target is unlikely to yield a
Joint Lead Compound, Joint Safety Assessment Compound or Joint Development
Compound, as the case may be, or (ii) a Lead Compound is not selected for Lead
Optimization following Lead Generation using a given Joint

                                       11
<PAGE>

Target and the Parties have not agreed to undertake additional research as
provided in Section 3.8 with respect to that Joint Target, then the Research
Term or Development Term, as the case may be, relating to the given Joint Target
shall terminate. In either such case, the JSC or the JDC, as the case may be,
shall document the reasons for termination of the Research Program or
Development Program, as the case may be, including the known or suspected
reasons that Compounds failed to meet the guidelines or criteria established for
a Lead Compound, if applicable, to provide a basis for potential re-instatement
of such programs under Sections 3.10 and 3.11 and Sections 4.10.4 and 4.10.5,
respectively.

               2.4.6  For each project undertaken during the Research Program or
Development Program, as the case may be, the JSC or the JDC will select either
Athersys, 3DP or both to maintain comprehensive project projections, budgets and
tracking reports in accordance with the Lead Optimization Plan, the Pre-Clinical
Development Plan and the Clinical Development Plan.

               2.4.7  The JSC and the JDC shall have such other responsibilities
as are expressly set forth elsewhere in this Agreement or as are assigned to it
as mutually agreed upon by the Parties.

         2.5   Voting. Regardless of the number of representatives from each
               ------
Party, each Party shall present one consolidated view and have one vote on any
issue in dispute. If the JSC or the JDC fails to reach agreement on any matter
within the scope of its responsibilities as described in this Agreement or as
expressly delegated to the JSC or the JDC by written agreement of the Parties,
the dispute shall be resolved as provided in ARTICLE 15.

         2.6   Opinion of Patent Counsel. The JSC may, at its discretion, retain
               -------------------------
patent counsel to provide an analysis and legal opinion regarding possible
infringement of Third Party patents by the use of Joint Targets or Compounds in
the Research Program.

                                   ARTICLE 3
                                RESEARCH PROGRAM

         3.1   Goal of Research Program. The goal of the Research Program is to
               ------------------------
identify at least one Compound as a Lead Compound for each of the 3DP Target,
the Athersys Target and the [*  *] Joint Targets. Schedule 1.14 graphically
                                                  -------------
depicts the elements of the Research Program and its relationship to elements of
the Development Program.

         3.2   Selection of Athersys Target and 3DP Target. Promptly following
               -------------------------------------------
the Effective Date, Athersys shall select the Athersys Target and 3DP shall
select the 3DP Target. In the event that the Parties each select the same
Target, that Target shall become one of the [*  *] Joint Targets. A Party can
reject the selection by the other Party of a 3DP Target or Athersys Target prior
to initiation of Screen Development:

               3.2.1  if the rejecting Party reasonably believes that use of
such 3DP Target or Athersys Target, as applicable, would create a commercially
unacceptable risk of infringement of dominating Patent Rights of Third Parties;

                                       12
<PAGE>

               3.2.2  for which the rejecting Party has a preexisting, ongoing
and active internal research program for which cell line development or
screening has commenced before its designation as an Athersys Target or 3DP
Target, as applicable; or

               3.2.3  for which the rejecting Party has a preexisting exclusive
collaborative arrangement with a Third Party or is engaged in bona fide
negotiations with a Third Party regarding the same before its designation as an
Athersys Target or a 3DP Target, as applicable.

         3.3   Rejection. Notwithstanding the foregoing, if a Party rejects the
               ---------
selection of the other Party's designation of a 3DP Target or Athersys Target,
as applicable, such rejecting Party may not designate such rejected Target as
its own 3DP Target or Athersys Target, as applicable.

         3.4   Selection/Rejection of Joint Targets. In addition to any Targets
               ------------------------------------
that become Joint Targets pursuant to Section 3.2, the JSC shall select
additional Targets from among the Candidate Targets until there are a total of
[*  *] Joint Targets. The Parties will strive to select Joint Targets that (i)
are complementary to both Parties' current therapeutic area/disease focus for
its internal drug discovery efforts and (ii) are amenable to screening in a
Primary Screen. Either Party can reject the selection of a Joint Target prior to
initiation of Screen Development:

               3.4.1  if that Party reasonably believes that use of such Target
would create a commercially unacceptable risk of infringement of dominating
Patent Rights of Third Parties;

               3.4.2  for which a Party has a preexisting, ongoing and active
internal research program for which cell line development or screening has
commenced before its designation as a Joint Target;

               3.4.3  for which a Party has a preexisting exclusive
collaborative arrangement with a Third Party or is engaged in bona fide
negotiations with a Third Party regarding the same before its designation as a
Joint Target;

               3.4.4  that, for either scientific, technical or business reasons
in such Party's reasonable judgment, do not have a reasonable likelihood of
leading to a commercially successful Product that is a Small Molecule; or

               3.4.5  that does not have a readily identifiable market size or
value significant enough to justify the anticipated Research Program and
Development Program investments of such Party.

         3.5   Athersys Responsibilities.
               -------------------------

               3.5.1  As specifically described in Schedule 3.5, Athersys shall
                                                   ------------
be responsible for Screen Development using the RAGE-VT Technology in Primary
Screens and Secondary Screens and the screening of Compounds provided by 3DP
using the Athersys Target, the 3DP Target and the Joint Targets.

               3.5.2  Athersys shall use reasonable efforts to develop all
Primary Screens using the Athersys Target, the 3DP Target and the Joint Targets
and to screen Compounds provided by

                                       13
<PAGE>

3DP in all such Primary Screens in parallel. To the extent that resource
limitations preclude such parallel efforts, first priority shall be given to
[*  *] Joint Targets after which the 3DP Target shall be given priority over the
Athersys Target, which shall be given priority over the remaining Joint Target;
provided, however, that it is acknowledged that due to uncontrollable biological
variability Targets may be developed at different rates which may preclude
parallel or preferred screening sequence. Athersys shall use reasonable efforts
to screen all Compounds provided by 3DP for screening against each Joint Target
and the 3DP Target. To the extent that resource limitations require
prioritization of screening, 3DP shall prioritize the Compounds for screening
against Targets. Athersys, at its own discretion, may screen any or all
Compounds provided by 3DP against the Athersys Target.

               3.5.3  Athersys shall develop replacement screens using the 3DP
Target as provided in Section 3.6.2.

               3.5.4  Athersys shall be responsible for selecting the Athersys
Target and for approving the Primary Screens and Secondary Screens developed by
Athersys using the Athersys Target.

         3.6   3DP Responsibilities.
               --------------------

               3.6.1  As specifically described in Schedule 3.6 during Lead
                                                   ------------
Generation, 3DP will be responsible for providing subsets of [* *] Compounds
from the 3DP Probe Library for screening by Athersys in Primary Screens and
Secondary Screens of the Joint Targets, the Athersys Target and the 3DP Target,
and for all subsequent Compounds synthesized from the iterative rounds of
chemistry from the 3DP Synthetically Accessible Library and utilizing elements
of its Directed Diversity(R) Technology during Lead Generation using Joint
Targets, the Athersys Target and the 3DP Target.

               3.6.2  3DP shall be responsible for selecting the 3DP Target and
for approving the Primary Screens and Secondary Screens developed by Athersys
using the 3DP Target as set forth in Schedule 3.5. If 3DP reasonably determines
                                     ------------
that a Primary Screen or a Secondary Screen is unlikely to perform adequately to
yield a Lead Compound, then, subject to there being sufficient time remaining in
the Research Term, Athersys shall attempt to develop a replacement screen using
its existing capabilities on the same Target.

         3.7   Completion of Lead Generation. Lead Generation with respect to a
               -----------------------------
particular Target shall be deemed completed when at least one Compound is
selected as a Lead Compound or a maximum of [* *] rounds of iterative chemical
synthesis of Compounds selected from the 3DP Synthetically Accessible Libraries
with a [* *] Compounds are synthesized, subject to Iterative Chemistry
Limitations or screening results that do not provide a structure-activity
relationship.

         3.8   Additional Efforts. The JSC may determine that efforts additional
               ------------------
to those assigned to a Party in this Agreement (including the efforts set forth
in the Schedules hereto), e.g., selectivity assays, cell biology assays, animal
modeling, toxicological studies, ADME studies, etc., are warranted at any time
during the Research Program with respect to the Joint

                                       14
<PAGE>

Targets. In this case, the JSC will assign responsibility for such additional
efforts to a Party or will outsource the efforts subject to the cost sharing
provisions of Section 7.1.

         3.9   Termination of Research Program For a Joint Target. Upon
               --------------------------------------------------
termination of the Research Term for a Joint Target, as provided in Section
2.4.5, or upon expiration of the Research Term for a Joint Target:

               3.9.1  subject to Section 3.11, all further activities with
respect to such Joint Target hereunder shall cease;

               3.9.2  the Joint Target shall be counted as one of the [*  *]
Joint Targets; and

               3.9.3  this Agreement shall terminate with respect to such Joint
Target unless reinstated under Section 3.11.

         3.10  Optional 3DP Continued Research. 3DP, at its election any time
               -------------------------------
during the [*   *] period immediately following the termination date of the
Research Term for a Joint Target, may request in writing to Athersys to continue
the Research Program for the Joint Target independently of Athersys and at 3DP's
sole cost and expense. If 3DP so elects, Athersys shall provide 3DP with the
cells for the Primary Screen(s) and Secondary Screen(s) and the related know-how
for that Joint Target, and grants to 3DP a non-exclusive, royalty-free license
to use such cells during the remainder of such [*  *] period after notice by 3DP
solely for the purpose of continuing research to attempt to identify Lead
Compound(s) for that Joint Target. Should 3DP be successful in obtaining new
data or developing reasons that it believes overcome the prior reasons of the
JSC for terminating the Research Program, 3DP shall notify the JSC of such under
Section 3.11. Should 3DP be unsuccessful during such period in obtaining new
data or developing reasons that overcome the prior reasons of the JSC for
terminating the Research Program, 3DP shall return or destroy, as directed by
Athersys, the cells for the Primary Screen(s) and Secondary Screen(s), return
all physical embodiments of know-how provided by Athersys associated therewith,
and destroy all copies, in whole or in part, of such embodiments, and this
Agreement shall terminate with respect to such Joint Target.

         3.11  Re-instatement of Terminated Joint Target. If, at any time during
               -----------------------------------------
the [* *] period immediately following the Research Term for a Joint Target, 3DP
obtains new data that overcomes, or believes that changed circumstances
overcome, the prior reasons of the JSC for terminating the Research Program, 3DP
shall notify the JSC of such. Upon agreement of the JSC that the reasons
advocated by 3DP do overcome the JSC's prior reasons for termination of the
Research Program, 3DP shall give Athersys written notice thereof and of the
reasons and changed circumstances leading to the desire to reinitiate the
Research Program for such Joint Target. In that case, Athersys shall within
[* *] of receiving such notice, give notice to 3DP that it does or does not want
to reinitiate the Research Program for such Joint Target under the terms of this
Agreement; provided, however, that Athersys shall not be entitled to accept
re-instatement of the Research Program for such Joint Target if Athersys has
entered an agreement with a Third Party to co-develop (cost sharing, as opposed
to having merely licensed out the cells) Small Molecule drugs for that Joint
Target. If Athersys does not give notice within such time period, notifies 3DP
that

                                       15
<PAGE>

it does not desire to reinitiate the Research Program for such Joint Target, or
has agreed to co-develop that Joint Target with a Third Party, then 3DP shall
have the right to continue research and/or development on its own or with a
Third Party and Athersys shall be deemed to have opted out, as provided in
Section 4.9, as of the initiation of Lead Optimization Opt-Out Point, but such
exclusive right of 3DP as the Funding Party therein shall be subject to any then
existing rights Athersys has granted or agreed to grant to a Third Party, and
Section 6.1 shall not apply. For the avoidance of doubt and notwithstanding
anything to the contrary herein, the Research Term for any Joint Target shall
not extend and may not be reinstated under this Section 3.11 beyond [* *] from
the Effective Date, absent mutual agreement to the contrary. For the further
avoidance of doubt, during the [* *] period immediately following the Research
Term for a Joint Target, Athersys may not grant rights in the Joint Target to a
Third Party that would preclude 3DP from re-instating the Research Program under
this Agreement.

         3.12  [*                                                        *]:

               3.12.1 [*                                                 *];

               3.12.2 [*                                                 *];

               3.12.3 [*                                                 *];

               3.12.4 [*                                                 *]; and

               3.12.5 [*                                                 *].

         3.13  Expansion of Research Program. If the Parties mutually agree, the
               -----------------------------
Research Program will be expanded by adding additional targets identified by
Athersys through the RAGE-PE Technology or RAGE-VT Technology. 3DP and Athersys
shall discuss and agree to relative values of the RAGE-PE Technology or RAGE-VT
Technology and the ThermoFluor(R) Technology in conjunction with such expansion
of the Research Program. The Parties acknowledge that Targets other than the
Targets used in the expanded Research Program may be more amenable to the
application of the ThermoFluor(R) Technology for screening purposes, in addition
to use of screens developed by Athersys.

                                   ARTICLE 4
                               DEVELOPMENT PROGRAM

         4.1   Goal of Development Program; Development Plans. The goal of the
               ----------------------------------------------
Development Program is to move at least one Joint Lead Compound forward and to
develop it into a Joint Product for each of the [*  *] Joint Targets. Schedule
                                                                      --------
1.14 graphically depicts the elements of the Development Program and its
----
relationship to the Research Program. The responsibilities and obligations of
Athersys and 3DP in the Development Program shall be described in a Lead
Optimization Plan for each Joint Target and related Joint Lead Compound, in a
Pre-Clinical Development Plan for each Joint Safety Assessment Compound and in a
Clinical Development Plan for each Joint Development Compound. Such plans shall
address the specific roles and responsibilities of each Party, budgets (for the
completion of the particular

                                       16
<PAGE>

Development Program activity, i.e., Lead Optimization, Pre-Clinical Development,
                              ----
Phase I, Phase II or Phase III) tasks to be outsourced, timelines, key "go/no
go" decisions, objectives for each major activity including, manufacturing of
pre-clinical, clinical and commercial supplies, chemical profiles required to
advance Compounds, pre-clinical and clinical study plans including study
endpoints, formulation, development, regulatory and marketing strategies. The
Parties, through the JSC and the JDC, shall use diligent efforts in preparing
such plans (1) to achieve a 50/50 balance in utilization of their respective
internal resources to the extent possible, (2) to exploit the relative strengths
and skills of each Party, and (3) to utilize outsourcing to complement the
Parties' collective strengths, skills and resources and otherwise to avoid
unduly straining the resources of a Party.

         4.2   Responsibilities During the Development Program. The Athersys
               -----------------------------------------------
Target and the 3DP Target and the progress of Athersys Lead Compounds and 3DP
Lead Compounds through Lead Optimization, Pre-Clinical Development, Development
and commercialization are excluded from the Development Program. 3DP shall have
full responsibility for and control over 3DP Lead Compounds, 3DP Safety
Assessment Compounds, 3DP Development Compounds and 3DP Products. Athersys shall
have full responsibility for and control over development of Athersys Lead
Compounds, Athersys Safety Assessment Compounds, Athersys Development Compounds
and Athersys Products. All matters pertaining to the Joint Lead Compounds, Joint
Safety Assessment Compounds and Joint Development Compounds during the
Development Program shall be managed by the JSC for Joint Lead Compounds and by
the JDC for Joint Safety Assessment Compounds and Joint Development Compounds.

         4.3   Determination to Move from Lead Generation to Lead Optimization.
               ---------------------------------------------------------------
3DP shall determine whether or not to progress 3DP Compounds for which Lead
Generation is completed into Lead Optimization. Athersys shall determine whether
or not to progress Athersys Compounds for which Lead Generation is completed
into Lead Optimization. Subject to Section 4.4, the JSC shall determine whether
or not to progress Joint Compounds for which Lead Generation is completed into
Lead Optimization.

         4.4   Progression into Lead Optimization. The JSC shall progress Joint
               ----------------------------------
Compounds for which Lead Generation is completed into Lead Optimization if it
reasonably determines that:

               4.4.1  there is sufficient understanding of the
structure-activity relationships to design new Joint Compounds that are likely
to have greater Potency and to have adequate selectivity to justify investing in
Lead Optimization, Pre-Clinical Development and Clinical Development;

               4.4.2  a commercially feasible method for synthesizing such new
Compounds is foreseeable or reasonably anticipated and the area of chemistry
under consideration does not involve a commercially unacceptable risk of
violation of others' Intellectual Property;

               4.4.3  an economically reasonable strategy for conducting Lead
Optimization, Pre-Clinical Development and Clinical Development is reasonably
foreseeable; and

                                       17
<PAGE>

               4.4.4  the reasonably foreseeable market opportunity for a Joint
Product justifying the anticipated investment in a Development Program may
reasonably be expected to result from Lead Optimization.

               Upon consideration of the foregoing criteria and designation of a
Joint Compound as a Joint Lead Compound, the JSC shall develop a Lead
Optimization Plan for each Joint Target and related Joint Lead Compounds as
provided in Section 4.1.

         4.5   Athersys Responsibilities. During the Development Program and to
               -------------------------
the extent consistent with its internal capabilities, Athersys shall be
responsible for developing models for pre-clinical confirmation of
pharmacological activity, and screening Joint Lead Compounds and Joint Safety
Assessment Compounds.

         4.6   3DP Responsibilities. During the Development Program and to the
               --------------------
extent consistent with its internal capabilities, 3DP shall be responsible for
medicinal chemistry aspects of Lead Optimization and synthesizing derivatives of
Joint Lead Compounds during Lead Optimization.

         4.7   Progression into Pre-Clinical Development and Clinical
               ------------------------------------------------------
Development. The JSC shall determine when to terminate Lead Optimization using
-----------
Joint Lead Compounds and whether or not to designate such Joint Lead Compounds
as Safety Assessment Compounds for Pre-Clinical Development. The JDC shall
determine how to progress a Safety Assessment Compound through Pre-Clinical
Development and onwards into and through Clinical Development.

         4.8   Development Efforts. Each Party will exercise its reasonable
               -------------------
efforts and diligence in developing Joint Lead Compounds, Joint Safety
Assessment Compounds and Joint Development Compounds and in undertaking all
investigations and actions required to obtain appropriate Regulatory Approvals
to develop and market Joint Products.

         4.9   Opting Out.
               ----------

               4.9.1  Discontinuing Party; Funding Party. Either Party may
                      ----------------------------------
terminate its responsibilities under this Agreement with respect to any or all
Joint Lead Compounds, Joint Safety Assessment Compounds or Joint Development
Compounds as provided in Section 14.3. In this event, the other Party shall have
the exclusive right and, at its election, may continue to develop the relevant
compound or compounds and the Party opting out (the "Discontinuing Party") shall
                                                     -------------------
provide reasonable ongoing assistance during a reasonable transition period. The
Discontinuing Party shall have no continuing funding obligations after the
Opt-Out Point, and the other Party (the "Funding Party"), if it elects to
                                         -------------
continue the Development Program, [*   *] (i.e., Lead Optimization, Pre-Clinical
                                           ----
Development, Phase I, Phase II, or Phase III) [*   *], whichever is shorter;
provided, however, such budget funding obligation shall not apply if the Funding
Party licenses out, assigns or sells rights in such compound [*   *].

                                       18
<PAGE>

               4.9.2  Discontinuing Party Duties. In the event that Athersys
                      --------------------------
becomes a Discontinuing Party for a Joint Lead Compound, Joint Safety Assessment
Compound or Joint Development Compound, Athersys will provide 3DP with the cells
for the Primary Screen(s) and Secondary Screen(s) and the related know-how for
that Joint Target. In the event that 3DP becomes a Discontinuing Party for a
Joint Lead Compound, Joint Safety Assessment Compound or Joint Development
Compound, 3DP will provide Athersys with the know-how associated with such
Compound(s) for that Joint Target.

         4.10  Termination of Development Program for a Joint Compound. If
               -------------------------------------------------------
(i) the JSC or the JDC, as applicable, determines not to progress a Joint Lead
Compound, Joint Safety Assessment Compound or Joint Development Compound on to
the next stage of the Development Program or (ii) both Parties opt-out with
respect to continued development of any Joint Lead Compound, Joint Safety
Assessment Compound or Joint Development Compound (i.e., both Parties become
Discontinuing Parties), then:

               4.10.1 the JSC or JDC shall promptly give written notice to the
Parties confirming such termination or mutual opt-out;

               4.10.2 subject to Section 4.10.5, all further activities with
respect to such Joint Lead Compound, Joint Safety Assessment Compound or Joint
Development Compound, as the case may be, hereunder shall cease;

               4.10.3 the Development Term shall expire and this Agreement shall
terminate with respect to such Joint Lead Compound, Joint Safety Assessment
Compound or Joint Development Compound, as the case may be, unless reinstated
under Section 4.10.5; and

               4.10.4 at 3DP's request, during the [*  *] period immediately
following the expired Development Term, Athersys shall promptly provide 3DP with
the cells for the Primary Screen(s) and Secondary Screen(s) and the related
know-how for that Joint Target, and grants to 3DP a non-exclusive, royalty-free
license to use such cells during the remainder of such [*  *] period after 3DP's
request solely for the purpose of generating data that may cause the Parties to
re-instate the Development Program; and

               4.10.5 except for the purpose of generating data that may cause
the Parties to re-instate the Development Program, during this [*  *], neither
3DP nor Athersys, independent of the other Party, shall use the Joint Lead
Compound, Joint Safety Assessment Compound or Joint Development Compound for
Lead Optimization, Pre-Clinical Development or Clinical Development unless 3DP
or Athersys, as the case may be, first (a) obtains the agreement of the JSC that
changed circumstances warrant re-instating the Development Program for such
Compound and that the prior reasons of the JSC for terminating the Development
Program have been overcome and (b) offers to the other Party the ability to
re-instate Lead Optimization, Pre-Clinical Development or Clinical Development
under this Agreement and to extend the Development Term for this purpose and
such other Party opts-out in accordance with Section 4.9. A Party's failure to
accept re-instatement of the Development Program within [*  *] of receiving a
valid request under subsection 4.10.6(b) shall be deemed an opt-out in
accordance with Section 4.9.

                                       19
<PAGE>

                                   ARTICLE 5
                                COMMERCIALIZATION

         5.1   Commercialization of Joint Products. Unless a Party has elected
               -----------------------------------
to opt out in accordance with Section 4.9, upon the initiation of a Phase III
trial for a Joint Development Compound, or earlier if the Parties mutually
agree, the Parties shall, enter into a written agreement setting forth the terms
under which the Parties will jointly commercialize the Joint Product. While the
basis of cost and profit sharing will be [* *], items to be covered in such
agreement will include which countries to launch directly, where to partner, how
many field forces will detail product, who will promote a Joint Product, how
pricing will be determined, and sales and marketing strategy.

         5.2   Division of Revenues for Joint Products.
               ---------------------------------------

               5.2.1  Profits from commercialization of a Joint Product by the
Parties shall be shared [* *] by the Parties. LMPs derived from a Joint Product
as well as any royalties paid by a Third Party to the Parties derived from Net
Sales by such Third Party of a Joint Product shall also be shared [* *].

               5.2.2  In the event that a Party elects to opt out as provided in
Section 4.9, and if the other Party elects to continue the Development Program
as a Funding Party, then the Funding Party shall share Profits or LMPs derived
from commercializing the former Joint Product, i.e., the then Athersys Product
or the then 3DP Product, as the case may be, and shall pay a royalty on Net
Sales thereof, the value of which shall depend upon the point at which the
Discontinuing Party discontinued funding, as provided in Schedule 5.2.
                                                         ------------

         5.3   Athersys Product Commercialization.
               ----------------------------------

               5.3.1  Upon commercialization by Athersys of an Athersys Product,
Athersys shall pay 3DP an amount equal to [* *] of Profits of such Athersys
Product. In addition, Athersys shall pay to 3DP a royalty equal to [* *] of Net
Sales of the Athersys Product.

               5.3.2  If Athersys licenses, assigns or sells to a Third Party
the rights to an Athersys Product during Lead Optimization for such Athersys
Product, then Athersys shall pay 3DP an amount equal to [* *] of LMPs of such
Athersys Product. In addition, Athersys shall pay to 3DP a royalty equal to [*
*] of Net Sales of the Athersys Product by such Third Party.

               5.3.3  If Athersys licenses, assigns or sells to a Third Party
the rights to an Athersys Product during Pre-Clinical Development for such
Athersys Product, then Athersys shall pay 3DP an amount equal to [* *] of LMPs
of such Athersys Product. In addition, Athersys shall pay to 3DP a royalty equal
to [* *] of Net Sales of the Athersys Product by such Third Party.

               5.3.4  If Athersys licenses, assigns or sells to a Third Party
the rights to an Athersys Product during Phase I for such Athersys Product, then
Athersys shall pay 3DP an

                                       20
<PAGE>

amount equal to [* *] of LMPs of such Athersys Product. In addition, Athersys
shall pay to 3DP a royalty equal to [* *] of Net Sales of the Athersys Product
by such Third Party.

               5.3.5  If Athersys licenses, assigns or sells to a Third Party
the rights to an Athersys Product during Phase II for such Athersys Product,
then Athersys shall pay 3DP an amount equal to [* *] of LMPs of such Athersys
Product. In addition, Athersys shall pay to 3DP a royalty equal to [* *] of Net
Sales of the Athersys Product by such Third Party.

               5.3.6  If Athersys licenses, assigns or sells to a Third Party
the rights to an Athersys Product during Phase III for such Athersys Product,
then Athersys shall pay 3DP an amount equal to [* *] of LMPs of such Athersys
Product. In addition, Athersys shall pay to 3DP a royalty equal to [* *] of Net
Sales of the Athersys Product by such Third Party.

               5.3.7  With respect to each license, assignment or sale, the
amounts payable under the foregoing Sections 5.3.1 through 5.3.6 are all
mutually exclusive of one another such that Athersys shall only pay such amounts
and royalties under the first to occur of any such Section for the same
transaction and as exemplified in Schedule 5.3.7. Any royalty obligation will
                                  --------------
continue only for the duration of the Royalty Term. Section 5.2.2, but not this
Section 5.3, shall apply to commercialization, license, assignment or sale of
Athersys Products which are former Joint Products for which 3DP opted out. [*
*].

         5.4   3DP Product Commercialization.
               -----------------------------

               5.4.1  Upon commercialization by 3DP of a 3DP Product, 3DP shall
pay Athersys an amount equal to [* *] of Profits of 3DP Product. In addition,
3DP shall pay to Athersys a royalty equal to [* *] of Net Sales of the 3DP
Product.

               5.4.2  If 3DP licenses, assigns or sells to a Third Party the
rights to a 3DP Product during Lead Optimization for such 3DP Product, then 3DP
shall pay Athersys an amount equal to [* *] of LMPs of such 3DP Product. In
addition, 3DP shall pay to Athersys a royalty equal to [* *] of Net Sales of the
3DP Product by such Third Party.

               5.4.3  If 3DP licenses, assigns or sells to a Third Party the
rights to a 3DP Product during Pre-Clinical Development for such 3DP Product,
then 3DP shall pay Athersys an amount equal to [* *] of LMPs of such 3DP
Product. In addition, 3DP shall pay to Athersys a royalty equal to [* *] of Net
Sales of the 3DP Product by such Third Party.

               5.4.4  If 3DP licenses, assigns or sells to a Third Party the
rights to a 3DP Product during Phase I for such 3DP Product, then 3DP shall pay
Athersys an amount equal to [* *] of LMPs of such 3DP Product. In addition, 3DP
shall pay to

                                       21
<PAGE>

Athersys a royalty equal to [* *] of Net Sales of the 3DP Product by such Third
Party.

               5.4.5  If 3DP licenses, assigns or sells to a Third Party the
rights to a 3DP Product during Phase II for such 3DP Product, then 3DP shall pay
Athersys an amount equal to [* *] of LMPs of such 3DP Product. In addition, 3DP
shall pay to Athersys a royalty equal to [* *] of Net Sales of the 3DP Product
by such Third Party.

               5.4.6  If 3DP licenses, assigns or sells to a Third Party the
rights to a 3DP Product during Phase III for such 3DP Product, then 3DP shall
pay Athersys an amount equal to [* *] of LMPs of such 3DP Product. In addition,
3DP shall pay to Athersys a royalty equal to [* *] of Net Sales of the 3DP
Product by such Third Party.

               5.4.7  With respect to each license, assignment or sale, the
amounts under the foregoing Sections 5.4.1 through 5.4.6 are all mutually
exclusive of one another such that 3DP shall only pay such amounts and royalties
under the first to occur of any such Section for the same transaction and as
exemplified in Schedule 5.3.7. Any royalty obligation will continue only for the
               --------------
duration of the Royalty Term. Section 5.2.2, but not this Section 5.4, shall
apply to commercialization, license, assignment or sale of 3DP Products which
are former Joint Products for which Athersys opted out. [* *].

                                    ARTICLE 6
                                   EXCLUSIVITY

         6.1   Athersys Restriction. Subject to any obligations of Athersys that
               --------------------
exist prior to designation of a Candidate Target as a Joint Target, during the
Research Term, Development Term and Royalty Term for each of the 3DP Target and
the Joint Targets, respectively, Athersys shall not, through use of the RAGE-VT
Technology, RAGE-PE Technology or otherwise, (i) provide the 3DP Target or the
Joint Targets to any Third Party for Small Molecule drug discovery or
development against the 3DP Target or the Joint Targets or (ii) run Small
Molecule screens against the 3DP Target or Joint Targets for purposes of drug
discovery or development directed thereto, except as explicitly allowed pursuant
to the terms of this Agreement. For the avoidance of doubt, the foregoing shall
not be construed to restrict Athersys' ability to license to others or use
itself the 3DP Target or Joint Targets for purposes of developing therapeutics
other than Small Molecule drugs and/or counterscreening, i.e., screening to
determine specificity for another drug discovery target.

         6.2   3DP Restriction. During the Research Term, Development Term and
               ---------------
Royalty Term for each of the Athersys Target and the Joint Targets and the
Athersys Lead Compound and Joint Lead Compounds, respectively, 3DP shall not,
through the use of its 3DP Probe Library, 3DP Synthetically Accessible Library,
DiscoverWorks(TM) Technology or otherwise, use or provide its chemically
synthesizable libraries with or to any Third Party for screening Small Molecules
against the Joint Targets or the Athersys Target.

                                       22
<PAGE>

                                   ARTICLE 7
                       COSTS AND FINANCIAL RECORD KEEPING

         7.1   Research Program Costs. Athersys and 3DP agree to provide their
               ----------------------
relevant technologies as set forth in Schedule 3.5 and Schedule 3.6,
                                      ------------     ------------
respectively, in support of the Research Program. The costs incurred by each
Party for such support are considered equivalent and there will be no
requirement for any financial settlement between the Parties in respect of the
application of the technologies of either Party for such purpose. The Parties
estimate that the total cost for the Research Program will be [* *] for each
Target, i.e., [* *] for each Party and for each Target ("Research Program
                                                         ----------------
Costs"). If the JSC determines, in accordance with Section 3.8, that efforts
-----
additional to those assigned to a Party in this Agreement including the
Schedules hereto, e.g., selectivity assays, cell biology assays, animal
                  ----
modeling, toxicological studies, ADME studies, etc., are warranted at any time
during the Research Program with respect to the Joint Targets, then the Parties
shall share these costs equally. The JSC will select patent counsel to provide
an analysis and legal opinion regarding possible infringement of Third Party
patents by the use of proposed Joint Targets, with such costs to be shared
equally between the Parties. Each Party will be responsible for the expense for
any independent analysis on the Joint Targets, or the 3DP Target or the Athersys
Target, that it may choose to obtain.

         7.2   Development Program Costs. For Joint Lead Compounds, Joint Safety
               -------------------------
Assessment Compounds and Joint Development Compounds, the Parties will mutually
agree which Party or contract organization shall conduct each task beyond Lead
Generation, recognizing each Party's then-existing competencies and expertise.
All costs and expenses for activities during the Development Program will be
shared equally, including, without limitation, the costs of FTEs, at the FTE
Rate, and out-of-pocket costs paid to Third Parties in accordance with budgeted
items approved by the JSC or JDC, as applicable, and set forth in the Lead
Optimization Plans, Pre-Clinical Development Plans, and Clinical Development
Plans. To the extent any such cost or expense will exceed such pre-approved
budgeted item by more than the lesser of (a) [* *] or (b) [* *], the Party
incurring such excess cost or expense shall be solely responsible for such cost
or expense unless such additional amount was approved in advance by the JSC or
the JDC, as applicable.

         7.3   Record Keeping. For a period of two (2) years after the end of
               --------------
the Development Term, the Parties shall keep complete and accurate records of
its FTEs and out-of-pocket costs and expenses directly related to the
Development Program to the extent made or incurred by such Party during the
Development Program.

         7.4   Quarterly Reconciliation.
               ------------------------

               7.4.1  Within thirty (30) days following the end of each calendar
quarter, Athersys shall submit to 3DP a written report setting forth in
reasonable detail, separately with respect to each Joint Lead Compound, Joint
Safety Assessment Compound and Joint Development Compound, all FTEs and
out-of-pocket costs and expenses to the extent made or incurred by Athersys
during the Development Program and in accordance with Section 7.2.

                                       23
<PAGE>

               7.4.2  Within thirty (30) days following the end of each calendar
quarter, 3DP shall submit to Athersys a written report setting forth in
reasonable detail, separately with respect to each Joint Target, Joint Lead
Compound, Joint Safety Assessment Compound and Joint Development Compound, all
FTEs and out-of-pocket costs and expenses to the extent made or incurred by 3DP
during the Development Program and in accordance with Section 7.2.

               7.4.3  Within forty-five (45) days following the end of each
calendar quarter, 3DP shall submit to Athersys a written report setting forth in
reasonable detail the costs and expenses incurred by each Party during the
Development Program and the calculation of any net amount owed by Athersys to
3DP or by 3DP to Athersys, as the case may be, in order to ensure an equal
sharing of such costs and expenses during the Development Program. The net
amount payable shall be paid by 3DP or Athersys, as the case may be, within
fifteen (15) days after receipt of such written report, without regard to any
dispute as to the amounts under this Section 7.4.3; provided that the amounts
are in accordance with Section 7.2, and that, in the event of a dispute, the
disputing Party shall provide written notice within such fifteen (15) day period
after receipt of the written report in question, specifying in detail such
dispute. The Parties shall promptly thereafter meet and negotiate in good faith
a resolution to such dispute. In the event that the Parties are unable to
resolve such dispute within thirty (30) days after notice by the disputing
Party, the matter shall be resolved in a manner consistent with the procedures
set forth in Section 15.2, provided, that, in the case that the matter has not
been resolved by the Chief Executive Officers, such matter shall be referred to
an internationally recognized independent accounting firm acceptable to both
Parties for binding resolution. Any outstanding amounts payable following
resolution shall be subject to interest calculated using the prime rate plus
three percent (3%) for the time from which the amounts should have been paid
until the time of actual payment.

         7.5   Audits. Each Party shall keep complete and accurate records of
               ------
the underlying costs and expense data relating to the reports and payments
required by Section 7.4. Each Party will have the right once annually at its own
expense to have an independent, certified public accountant, selected by such
Party and reasonably acceptable to the other Party, review any such records of
the other Party in the location(s) where such records are maintained by the
other Party upon reasonable notice and during regular business hours and under
obligations of strict confidence, for the sole purpose of verifying the basis
and accuracy of payments made, in each case within the prior twenty-four (24)
month period. If the review of such records reveals that the other Party has
failed to accurately report information, then the other Party shall promptly pay
to the auditing Party any resulting amounts due, together with interest
calculated using the prime rate plus three percent (3%) for the time from which
the amounts should have been paid until the time of actual payment. If any
amounts due under Section 7.4 as a result of such audit are greater than five
percent (5%) of the amounts actually due for a calendar year, the other Party
shall pay all of the costs of such review. If a Party in good faith disputes any
conclusion of the accounting firm under this Section 7.5, including that such
Party owes additional amounts, then such Party shall inform the other Party by
written notice within thirty (30) days of receipt of a copy of the audit in
question, specifying in detail such dispute. The Parties shall promptly
thereafter meet and negotiate in good faith a resolution to such dispute. In the
event that the Parties are unable to resolve such dispute within thirty (30)
days after notice by the disputing Party, the matter shall be resolved in a
manner consistent with the procedures set forth in Section

                                       24
<PAGE>

15.2, provided, that, in the case that the matter has not been resolved by the
Chief Executive Officers, such matter shall be referred to an internationally
recognized independent accounting firm acceptable to both Parties for binding
resolution. Any amounts payable at the conclusion of such dispute shall include
interest calculated using the prime rate plus three percent (3%) for the time
from which the amounts should have been paid until the time of actual payment.

                                   ARTICLE 8
                                 CROSS-LICENSES

         8.1   License Grant by 3DP.
               --------------------

               8.1.1  3DP grants to Athersys a royalty-free, non-exclusive
license under its Patent Rights and know-how to use Compounds for purposes of
discovering and developing an Athersys Lead Compound, an Athersys Safety
Assessment Compound and/or an Athersys Development Compound. This license shall
terminate when and to the extent it is no longer required for the stated
purposes. For the avoidance of doubt, this license includes the right to
sublicense rights in Athersys Lead Compounds, Athersys Safety Assessment
Compounds and Athersys Development Compounds to Third Parties for the purpose of
licensing out rights in an Athersys Product as contemplated by Sections 5.3.2 -
5.3.6.

               8.1.2  3DP grants to Athersys the exclusive right, with the right
to grant sublicenses, under 3DP's Patent Rights and know-how, to make, have
made, use, import, offer for sale and sell Athersys Products under the terms of
this Agreement. The license grant under this Section 8.1.2 is present, shall
terminate when and to the extent it is no longer required for the stated
purposes and is not conditioned upon the Parties reaching agreement as to the
form and substance of any future separate license agreement, if any, documenting
such license.

         8.2   License Grant by Athersys.
               -------------------------

               8.2.1  Athersys grants to 3DP a royalty-free, non-exclusive
license under Athersys' Patent Rights and know-how to use the cell lines
developed by Athersys that express the 3DP Target for Lead Generation, Lead
Optimization, Pre-Clinical Development and Clinical Development of 3DP
Compounds, 3DP Lead Compounds, 3DP Safety Assessment Compounds and 3DP
Development Compounds under this Agreement. This license shall be exclusive in
the field of Small Molecule drug discovery and development. This license shall
terminate when and to the extent it is no longer required for the stated
purposes.

               8.2.2  Athersys grants to 3DP a royalty-free, non-exclusive
license to use the cell lines developed by Athersys that express the Joint
Targets for Lead Generation, Lead Optimization, Pre-Clinical Development and
Clinical Development of Joint Compounds, Joint Lead Compounds, Joint Safety
Assessment Compounds and Joint Development Compounds under this Agreement. This
license shall terminate when and to the extent it is no longer required for the
stated purposes or as may be otherwise provided in the commercialization
agreement contemplated under Section 5.1.

               8.2.3  Athersys grants to 3DP the exclusive right, with the right
to grant sublicenses, under its Patent Rights and know-how, to make, have made,
use, import, offer for

                                       25
<PAGE>

sale and sell, under the terms of this Agreement, 3DP Products. The license
under this Section 8.2.3 is present, shall terminate when and to the extent it
is no longer required for the stated purposes and is not conditioned upon the
Parties reaching agreement as to the form and substance of any future separate
license agreement, if any, documenting such license.

               8.2.4 If 3DP wishes to use cell lines developed by Athersys to
screen Compounds against Targets other than the 3DP Target or Joint Targets, 3DP
will notify Athersys and Athersys and 3DP shall use good faith efforts to agree
to a license upon commercially reasonable terms for such additional screening.

         8.3   3DP's Libraries. Notwithstanding: (i) the exclusive license
               ---------------
granted to Athersys in ARTICLE 8, (ii) the ownership by Athersys of Athersys
Lead Compounds synthesized by Athersys, Athersys Development Compounds and
Athersys Safety Assessment Compounds as provided in ARTICLE 11, (iii) any Patent
Rights Athersys may acquire as a result of Lead Optimization under this
Agreement, or (iv) anything to the contrary in this Agreement, 3DP shall have
the free and unencumbered right to use the 3DP Synthetically Accessible Library,
the 3DP Probe Library, any other 3DP Small Molecule chemical compound libraries,
as they exist now or in the future and including each and every compound in the
libraries even if the compounds are Athersys Lead Compounds, Athersys Safety
Assessment Compounds, Athersys Development Compounds or Athersys Products,
solely for purpose of screen development and lead generation by 3DP (such terms
to be construed as consistently as possible with the terms "Screen Development"
and "Lead Generation" as defined hereunder).

                                   ARTICLE 9
             RESEARCH PROGRAM AND DEVELOPMENT PROGRAM RECORD KEEPING

         9.1   Laboratory Notebooks. All work conducted by either Party in the
               --------------------
course of the Research Program and the Development Program shall be completely
and accurately recorded, in sufficient detail and in good scientific manner, in
laboratory notebooks kept separately from the other research and development
activities of the Party.

         9.2   Audit. On reasonable notice, and at reasonable intervals, each
               -----
Party shall have the right to inspect and copy all such records of the other
Party reflecting inventions, ideas, information or data developed in the course
of or work done under the Research Program or the Development Program, to the
extent reasonably required to carry out its respective obligations and to
exercise its respective rights hereunder. Notwithstanding the definition of
"Confidential Information," all such records shall constitute Confidential
Information of the Party creating such records.

         9.3   Policies for Maintaining Records; Assignments of Inventions. In
               -----------------------------------------------------------
order to protect the Parties' Patent Rights under U.S. law in any inventions
conceived or reduced to practice during or as a result of the Research Program
or the Development Program, each Party agrees to maintain a policy which
requires its employees to record and maintain all data and information developed
during the Research Program and Development Program in such a manner as to
enable the Parties to use such records to establish the earliest date of
invention and/or diligence to reduction to practice. At a minimum, the policy
shall require such individuals to record all inventions generated by them in
standard laboratory notebooks which are dated and corroborated

                                       26
<PAGE>

by non-inventors on a regular, contemporaneous basis. The policy shall also
require all employees engaged in the Research Program or Development Program to
assign all Intellectual Property conceived or reduced to practice in connection
therewith to their respective employer, and the Parties shall ensure that each
such employee has signed such an agreement before any work on the Research
Program or Development Program commences.

                                   ARTICLE 10
                            CONFIDENTIAL INFORMATION

         10.1  Confidentiality Obligations. The Parties agree that, for the term
               ---------------------------
of this Agreement and for ten (10) years thereafter, either Party that receives
Confidential Information (a "Receiving Party") from the other Party (a
                             ---------------
"Disclosing Party") shall keep completely confidential and shall not publish or
 ----------------
otherwise disclose and shall not use for any purpose (except as expressly
permitted hereunder) any Confidential Information furnished to it by the
Disclosing Party pursuant to this Agreement (including without limitation,
know-how), except to the extent that it can be established by the Receiving
Party that such Confidential Information: (a) was already known to the Receiving
Party, other than under an obligation of confidentiality from the Disclosing
Party; (b) was generally available to the public or otherwise part of the public
domain at the time of its disclosure to the Receiving Party; (c) became
generally available to the public or otherwise part of the public domain after
its disclosure and other than through any act or omission of the Receiving Party
in breach of this Agreement; (d) was subsequently lawfully disclosed to the
Receiving Party by a Third Party; (e) can be shown by written records to have
been independently developed by the Receiving Party without reference to the
Confidential Information received from the Disclosing Party and without breach
of any of the provisions of this Agreement; or (f) is information that the
Disclosing Party has specifically agreed in writing that the Receiving Party may
disclose. The obligations of confidentiality and non-use set forth in this
Section 10.1 shall also apply to biological material and chemical compounds and
associated information (including without limitation know-how) disclosed by one
Party to the other prior to or during the Term.

         10.2  Written Assurances and Permitted Uses of Confidential
               -----------------------------------------------------
Information.
-----------

               10.2.1 Each Party shall inform its employees and consultants who
perform work on the Research Program or the Development Program, of the
obligations of confidentiality specified in Section 10.1 and all such persons
shall be bound by the terms of confidentiality set forth therein.

               10.2.2 The Receiving Party may disclose Confidential Information
to the extent the Receiving Party is compelled to disclose such information by a
court or other tribunal of competent jurisdiction; provided however, that in
such case the Receiving Party shall immediately give notice to the Disclosing
Party so that the Disclosing Party may seek a protective order or other remedy
from said court or tribunal. In any event, the Receiving Party shall disclose
only that portion of the Confidential Information that, in the opinion of its
legal counsel, is legally required to be disclosed and will exercise reasonable
efforts to ensure that any such information so disclosed will be accorded
confidential treatment by said court or tribunal.

                                       27
<PAGE>

               10.2.3 To the extent it is reasonably necessary or appropriate to
fulfill its obligations and exercise its rights under this Agreement, either
Party may disclose Confidential Information to its Affiliates, on a need-to-know
basis on condition that such Affiliates agree to keep the Confidential
Information confidential for the same time periods and to the same extent as
such Party is required to keep the Confidential Information confidential under
this Agreement.

               10.2.4 The existence and the terms and conditions of this
Agreement which the Parties have not specifically agreed to disclose pursuant to
this Section 10.2 shall be treated by each Party as Confidential Information of
the other Party.

         10.3  Publication. 3DP and Athersys, by mutual consent, will jointly
               -----------
determine to publish or publicly present the results of the Research Program or
Development Program (the "Results") subject to the following terms and
                          -------
conditions:

               10.3.1 As soon as reasonably necessary after its formation, the
JSC or JDC, as applicable, will establish a long term strategic publication plan
governing publication of the Results and public appearances (congresses,
presentations, press releases, advisory boards and the like) with the goal to
use and combine all existing data to support and maximize the commercial success
of the Products (the "Publication Plan"). The Parties will each provide, from
                      ----------------
time to time, a list of proposed publications regarding Joint Compounds, Joint
Lead Compounds, Joint Safety Assessment Compounds, Joint Development Compounds,
Joint Targets or Joint Products to the JSC or JDC, as applicable, for mutual
approval, and a list of proposed publications regarding its own Compounds, Lead
Compounds, Safety Assessment Compounds, Development Compounds, Targets or
Products to the JSC or JDC, as applicable, for review and comment provided that
no approval will be required by the JSC or JDC, as applicable, or the other
Party for those Compounds, Lead Compounds, Safety Assessment Compounds,
Development Compounds, Targets or Products that are not jointly owned.
Authorship of each publication will be determined at time of submission for
publication based on the contributions provided thereto.

               10.3.2 The Party proposing to publish or publicly present the
Results (the "Publishing Party") will submit thirty (30) days in advance, a
              ----------------
draft of any proposed manuscript or speech to the other Party (the
"Non-Publishing Party") for comments from the other Party and the JSC or JDC, as
 --------------------
applicable, and, if such proposed manuscript or speech involves Joint Compounds,
Joint Lead Compounds, Joint Safety Assessment Compounds, Joint Development
Compounds, Joint Targets or Joint Products, for approval by the JSC or JDC, as
applicable, and inclusion in the Publication Plan.

               10.3.3 The Parties will use their best efforts to gain the right
to review proposed publications by consultants or contractors relating to the
subject matter of the Research Program.

               10.3.4 No Party may publish Confidential Information of the other
Party, the use of which is restricted under this ARTICLE 10, without the consent
of the other Party.

               10.3.5 If the Parties determine that patent protection is
suitable for any information or results desired to be published or such results
or information is the subject of patent protection, no Party may publish such
information or results without first obtaining

                                       28
<PAGE>

approval from patent counsel in charge of prosecuting that patent application
(who shall take into consideration the absolute novelty requirements of
applicable jurisdictions).

               10.3.6 This ARTICLE 10 shall be inapplicable to the publication
of information presented in substantially the same form in which was previously
published or disclosed to the public, and to any other disclosures which, on the
advice of counsel, are required by law to be disclosed.

         10.4  Permitted Disclosures. Notwithstanding anything to the contrary
               ---------------------
herein, either Party may, upon the advice of its counsel and without the prior
consent of the other Party, disclose or publish Confidential Information, the
name or the trademarks of the other Party or information concerning the Research
Program or Development Program as required by law, government regulation, court
order or alternative dispute resolution process, including without limitation in
connection with filings with the U.S. Securities and Exchange Commission or
otherwise pursuant to applicable securities laws and regulations, filings with
the Internal Revenue Service and otherwise pursuant to applicable tax laws and
regulations, or to comply with discovery or similar requests in litigation and
alternative dispute resolution proceedings; provided, however, in any such case
the Party seeking to make such disclosure or publication, if permissible under
all laws or regulations, provides the other Party with advance written notice of
such disclosure or publication and provides the other Party with a reasonable
opportunity to secure protection of the Confidential Information therein.

                                   ARTICLE 11
                        PATENTS AND INTELLECTUAL PROPERTY

         11.1  Ownership; Inventions.
               ---------------------

               11.1.1 Inventions. Inventorship for patentable inventions
                      ----------
conceived or reduced to practice during the course of the performance of
activities pursuant to this Agreement shall be determined in accordance with
U.S. patent laws for determining inventorship. Subject to Section 11.1.2,
ownership shall be initially determined based on inventorship. In the event of a
dispute regarding inventorship, if the Parties are unable to resolve such
inventorship dispute, the JSC shall establish a procedure to resolve such
dispute, which may include engaging a Third Party patent attorney jointly
selected by the Parties to resolve such dispute.

               11.1.2 Ownership.
                      ---------

                      (a)    Joint Targets, Joint Lead Compounds, Joint Safety
                             -------------------------------------------------
Assessment Compounds, Joint Development Compounds and Joint Products.
--------------------------------------------------------------------

                             (i)    Subject to Sections 11.1.2(a)(ii) and
11.1.2(e), each Party shall own a fifty percent (50%) undivided interest in all
inventions, discoveries and research information made, conceived, reduced to
practice or generated jointly by employees or agents of both Parties relating to
Joint Targets, Joint Lead Compounds, Joint Safety Assessment Compounds, Joint
Development Compounds and Joint Products. Each Party shall promptly notify the
other upon the making, conceiving or reducing to practice of any invention or
discovery referred to in this Section 11.1.2(a)(i). For purposes of this Section
11.1.2(a)(i), Joint

                                       29
<PAGE>

Lead Compounds shall only include Compounds that are synthesized through
medicinal chemistry during Lead Optimization and all other Lead Compounds shall
be owned, as between the Parties, by 3DP.

                             (ii)   In the event that either a Research Term for
a Joint Target expires or is terminated with no corresponding follow-on
Development Program or a Development Program for a Joint Target is terminated
with no corresponding follow-on Product, then as between the Parties, (A)
Athersys shall own all right, title and interest in and to the Joint Target and
any inventions, discoveries and research made, conceived, reduced to practice or
generated solely by either Party or jointly by employees or agents of both
Parties, subject to Sections 3.12.4 and 4.10.5, as applicable, and 3DP shall
execute all further instruments to document Athersys' ownership therein as
reasonably requested by Athersys, and (B) 3DP shall own all right, title and
interest in and to the Compounds screened against such Joint Target.

                             (iii)  Notwithstanding 11.1.2(a)(ii), in the event
that either a Research Term for a Joint Target expires or is terminated with no
corresponding follow-on Development Program or a Development Program for a Joint
Target is terminated with no corresponding follow-on Product, then as between
the Parties, each Party shall own a fifty percent (50%) undivided interest in
and to all right, title and interest in and to any inventions, discoveries and
research information made, conceived, reduced to practice or generated jointly
by employees or agents of both Parties relating to disease pathways or
mechanisms of action (e.g., a discovery that a certain Joint Target is useful as
a drug discovery target for a new indication or a discovery that a class of
drugs acts against a Joint Target). Each Party shall promptly notify the other
upon the making, conceiving or reducing to practice of any invention or
discovery referred to in this Section 11.1.2(a)(iii). Each Party shall execute
all further instruments to document each other's ownership therein as reasonably
requested by the other Party.

                      (b)    Athersys Targets, Athersys Lead Compounds, Athersys
                             ---------------------------------------------------
Safety Assessment Compounds, Athersys Development Compounds and Athersys
------------------------------------------------------------------------
Product. As between the Parties, Athersys shall exclusively own all Athersys
-------
Lead Compounds, Athersys Safety Assessment Compounds and Athersys Development
Compounds that are synthesized by Athersys through the use of its own
chemistries and that are not identical to Compounds provided by 3DP, subject
only to Patent Rights deriving from patent applications filed by 3DP prior to
Athersys' synthesis thereof. Athersys shall be the owner of inventions,
discoveries and research information made, conceived, reduced to practice or
generated relating to an Athersys Target, Athersys Lead Compound, Athersys
Safety Assessment Compound, Athersys Development Compound or Athersys Product.
In the event an employee, agent or other person under obligations to assign
inventions or discoveries to 3DP is deemed an inventor of such inventions or
discoveries that relate to an Athersys Target, Athersys Lead Compound, Athersys
Safety Assessment Compound, Athersys Development Compound or Athersys Product,
then 3DP hereby assigns its entire right, title and interest in such invention
to Athersys and shall execute all further instruments to document such
assignment as reasonably requested by Athersys. For purposes of this Section
11.1.2(b), Athersys Lead Compounds shall only include Compounds that are
synthesized by Athersys through medicinal chemistry during Lead

                                       30
<PAGE>

Optimization and all other Lead Compounds, subject to Section 11.1.2(a), shall
be owned, as between the Parties, by 3DP.

                      (c)    3DP Targets, 3DP Lead Compounds, 3DP Safety
                             -------------------------------------------
Assessment Compounds, 3DP Development Compounds and 3DP Products. 3DP shall be
----------------------------------------------------------------
the owner of inventions, discoveries and research information made, conceived,
reduced to practice or generated relating to a 3DP Target, 3DP Lead Compound,
3DP Safety Assessment Compound, 3DP Development Compound or 3DP Product. In the
event an employee, agent or other person under obligations to assign inventions
or discoveries to Athersys is deemed an inventor of such inventions or
discoveries that relate to a 3DP Target, 3DP Lead Compound, 3DP Safety
Assessment Compound, 3DP Development Compound, 3DP Target or 3DP Product, then
Athersys hereby assigns its entire right, title and interest in such invention
to 3DP, and shall execute all further instruments to document such assignment as
reasonably requested by 3DP.

                      (d)    Compounds. As between the Parties, 3DP shall retain
                             ---------
its ownership and Patent Rights and other intellectual property rights in all
Compounds delivered to Athersys. 3DP shall be the owner of inventions,
discoveries and research information made, conceived, reduced to practice or
generated by 3DP or by Athersys relating to all Compounds screened against Joint
Targets and Compounds that during Lead Generation do not become Joint Lead
Compounds, 3DP Lead Compounds or Athersys Lead Compounds. In the event an
employee, agent or other person under obligations to assign inventions or
discoveries to Athersys is deemed an inventor of such inventions or discoveries
that relate to a Compound that did not become Joint Lead Compounds, 3DP Lead
Compounds or an Athersys Lead Compound, then Athersys hereby assigns its entire
right, title and interest in such invention to 3DP, and shall execute all
further instruments to document such assignment as reasonably requested by 3DP.

                      (e)    Ownership After Opt-Out. From the Opt-Out Point,
                             -----------------------
the Joint Lead Compounds, Joint Safety Assessment Compounds or Joint Development
Compounds, as the case may be, shall be (a) owned exclusively by the Funding
Party, (b) subject to the division of Profits and LMPs and subject to the
royalty sharing provisions as set forth in Section 5.2.2, and (c) for all other
purposes, (i) if Athersys is the Funding Party, then considered an Athersys Lead
Compound, Athersys Safety Assessment Compound or Athersys Development Compound,
as applicable, or (ii) if 3DP is the Funding Party, then considered a 3DP Lead
Compound, 3DP Safety Assessment Compound or 3DP Development Compound, as
applicable. Athersys or 3DP, as the case may be, shall execute all further
instruments to document ownership in the former Joint Lead Compounds, Joint
Safety Assessment Compounds or Joint Development Compounds, as the case may be,
as reasonably requested by the owner thereof. For purposes of this Section
11.1.2(e), Joint Lead Compounds and Athersys Lead Compounds shall only include
Compounds that are synthesized through medicinal chemistry during Lead
Optimization.

         11.2  Prosecution and Maintenance of Patent Rights. The responsibility
               --------------------------------------------
for (a) preparing, filing and prosecuting patent applications (including
reissue, continuing, divisional, and substitute applications and any foreign
counterparts thereof); (b) for maintaining any Patent Rights; and (c) for
managing any interference or opposition proceedings relating to the foregoing
((a), (b) and (c) collectively, "Patent Prosecution") covering an invention
                                 ------------------
conceived or reduced to practice during the course of the performance of
activities pursuant to this Agreement shall be the responsibility of the Party
owning such invention. All Patent Prosecution expenses, including attorneys'
fees, incurred by a Party in the performance of Patent Prosecution of an
invention owned by one Party shall be borne by such Party. All Patent

                                       31
<PAGE>

Prosecution costs, including attorneys' fees, relating to Joint Targets, Joint
Lead Compounds, Joint Safety Assessment Compounds or Joint Development Compounds
shall be shared by the Parties in accordance with Section 11.3.

         11.3   Prosecution and Maintenance of Joint Targets, Joint Lead
                --------------------------------------------------------
Compounds, Joint Safety Assessment Compounds and Joint Development Compounds.
----------------------------------------------------------------------------

               11.3.1 Filing. The JSC or JDC, as appropriate, shall determine
                      ------
whether to conduct Patent Prosecution with respect to jointly-owned inventions.
The JSC or the JDC, as appropriate, will assign responsibility to one Party to
act as the lead Party for the Patent Prosecution of such patent(s) and
application(s); provided, however, that both Parties shall be entitled to
actively participate in such Patent Prosecution and shall jointly decide upon
the strategy and content of Patent Prosecution activities. The lead Party shall
keep the JSC or the JDC, as appropriate, and the other Party informed of the
status of all matters affecting such patents and applications and Patent
Prosecution, including providing a copy of all correspondence from all
governmental authorities, and consulting on the strategy and content of
submissions to such governmental authorities in advance of any Patent
Prosecution submissions.

               11.3.2 Costs. All costs incurred by the Parties in carrying out
                      -----
the foregoing Patent Prosecution for inventions relating to Joint Targets, Joint
Lead Compounds, Joint Safety Assessment Compounds or Joint Development Compounds
shall be borne by the Parties at equal shares, unless otherwise agreed in
writing.

               11.3.3 Discontinuance. If the lead Party elects not to continue
                      --------------
pursuing Patent Prosecution with respect to any rights within Patent Rights for
inventions relating to Joint Targets, Joint Lead Compounds, Joint Safety
Assessment Compounds or Joint Development Compounds, then the prosecuting Party
shall, subject to any contractual obligations to Third Parties, notify the other
Party in writing of such election at least thirty (30) days prior to the last
available date for action to preserve such Patent Rights. If such other Party
elects to continue Patent Prosecution, such other Party may do so and all costs
and expenses shall be shared by the Parties in accordance with Section 11.3.2.

         11.4  Cooperation. Each Party hereby agrees:
               -----------

               11.4.1 to make its employees, agents and consultants reasonably
available to the other Party (or to the other Party's authorized attorneys,
agents or representatives), to the extent reasonably necessary to enable the
lead Party to undertake Patent Prosecution;

               11.4.2 to provide the other Party with copies of all material
correspondence pertaining to Patent Prosecution with the U.S. Patent and
Trademark Office or its foreign counterparts;

               11.4.3 to cooperate, if necessary and appropriate, with the other
Party in gaining patent term extensions wherever applicable to Patent Rights;
and

                                       32
<PAGE>

               11.4.4 to endeavor in good faith to coordinate its efforts with
the other Party to minimize or avoid interference with the Patent Prosecution of
the other Party's patent applications.

         11.5  Third Party Infringement.
               ------------------------

               11.5.1 Notice. Except as provided in Section 11.5.2, each Party
                      ------
shall promptly provide, but in on event later than thirty (30) days, the other
with written notice reasonably detailing any known or alleged infringement of
the other Party's Patent Rights by a Third Party.

               11.5.2 Notice-ANDA Filing. Each Party shall promptly provide to
                      ------------------
the other Party copies of any allegations of alleged patent invalidity or
non-infringement of a patent or patents with respect to technology used in the
Research Program, Development Program or of a Target, Compound or Product
pursuant to a certification under 21 U.S.C. ss. 355(b)(2)(A)(iv) by a Third
Party filing an Abbreviated New Drug Application thereunder. Such copies shall
be provided promptly, but in any event within ten (10) business bays, of receipt
of such certification.

               11.5.3 Infringement Proceedings. Each Party shall have the sole
                      ------------------------
right, but not the obligation, to institute and direct legal proceedings against
any Third Party believed to be infringing the Patent Rights of such Party, that
covers an invention that relates to such owning Party's Target, Lead Compound,
Safety Assessment Compound, Development Compound or Product; provided, however,
that the Parties shall mutually agree on a course of action for instituting and
directing legal proceedings against any Third Party believed to be infringing
any such Patent Rights that relates to Joint Targets, Joint Lead Compounds,
Joint Safety Assessment Compounds, Joint Development Compounds or Joint
Products. All costs, including attorneys' fees, relating to such legal
proceedings shall be borne by the Party that owns such Patent Rights or, in the
case of Patent Rights that relate to Joint Targets, Joint Lead Compounds, Joint
Safety Assessment Compounds, Joint Development Compounds or Joint Products,
shared equally by the Parties. If the Parties share the expenses, the Parties
shall each recover its expenses after which all damages will be shared by the
Parties in proportion to their actual damages. If only one Party is bearing the
expense, then the Party not bearing any of the expense shall, after the other
Party recovers its expenses, receive a share of the remaining compensatory
damages in proportion to its actual damages up to the percentage such Party
would have received had it received a share of Profits, LMPs and/or a royalty on
Net Sales in accordance with Schedule 5.2 and Sections 5.3 and 5.4, as the case
                             ------------
may be.

               11.5.4 Cooperation in Patent Infringement Proceedings. In the
                      ----------------------------------------------
event that either 3DP or Athersys takes action pursuant to this Section 11.5,
the other Party shall cooperate to the extent reasonably necessary and at the
first Parties' sole expense. Upon the reasonable request of the first Party,
such other Party shall join the suit and shall be represented in any such legal
proceedings using counsel of its own choice. Neither Party shall settle any
claim or proceeding relating to Patent Rights owned in whole or in part by the
other Party without the prior written consent of such other Party, which consent
shall not be unreasonably withheld.

                                       33
<PAGE>

         11.6  Other Intellectual Property Infringement.
               ----------------------------------------

               11.6.1 Notice.
                      ------

                      (a)    Each Party shall notify the other in writing of any
allegations it receives from a Third Party that technology used in the Research
Program, Development Program or a Product infringes the intellectual property
rights of such Third Party. Such notice shall be provided promptly, but in no
event after more than fifteen (15) business days, following receipt of such
allegations

                      (b)    In the event that a Party receives notice that it
or any of its Affiliates have been individually named as a defendant in a legal
proceeding by a Third Party alleging infringement of a Third Party patent or
other intellectual property right as a result of the manufacture, production,
use, development, sale or distribution of technology used in the Research
Program, Development Program or of a Target, Compound or Product, such Party
shall immediately notify the other Party in writing and in no event notify them
later than ten (10) business days after the receipt of such notice. Such written
notice shall include a copy of any summons or complaint (or the equivalent
thereof) received regarding the foregoing.

               11.6.2 Cooperation. Each Party shall assist the other and
                      -----------
cooperate in the defense of such allegations at each Party's own expense.

               11.6.3 Settlement. The Parties shall keep each other informed of
                      ----------
the status of and of their respective activities regarding any litigation or
settlement thereof concerning Targets, Compounds or Products; provided however,
that no settlement or consent judgment or other voluntary final disposition of a
suit under this Section may be undertaken without the consent of the other Party
if such settlement would require the other Party to be subject to an injunction
or to make a monetary payment or would otherwise adversely affect the other
Party's rights under this Agreement.

         11.7  Patent Term Extensions. The Parties shall cooperate in good faith
               ----------------------
with each other in gaining patent term extension wherever applicable.

               11.7.1 The Parties shall determine which patents covering joint
inventions shall be extended.

               11.7.2 All filings for such extension shall be made by the Party
responsible for Patent Prosecution covering such joint invention; provided,
however, that in the event that the Party who is responsible for such Patent
Prosecution elects not to file for an extension, such Party shall (i) inform the
other Party of its intention not to file and (ii) grant the other Party the
right to file for such extension.

                                   ARTICLE 12
                         REPRESENTATIONS AND WARRANTIES

         12.1  Authority. Each Party represents and warrants that as of the
               ---------
Effective Date it has the full right, power and authority to enter into this
Agreement and that this Agreement has been

                                       34
<PAGE>

duly executed by such Party and constitutes a legal, valid and binding
obligation of such Party, enforceable in accordance with its terms.

         12.2  Commercially Reasonable Efforts. Each Party represents and
               -------------------------------
warrants that it will use good faith commercially reasonable and diligent
efforts to develop Products, consistent with sound business judgment and to
perform the activities for which it is responsible under the Research Program
and Development Program.

         12.3  No Conflicts. Each Party represents and warrants that the
               ------------
execution, delivery and performance of this Agreement do not conflict with, or
constitute a breach or default under any of its charter or organizational
documents, any law, order, judgment or governmental rule or regulation
applicable to it, or any material agreement, contract, commitment or instrument
to which it is a party.

         12.4  No Existing Third Party Rights. Each Party represents and
               ------------------------------
warrants that its obligations under this Agreement are not encumbered by any
rights granted by such Party to any Third Parties that are or may be
inconsistent with the rights and licenses granted in this Agreement.

         12.5  Intellectual Property. Each Party represents and warrants to the
               ---------------------
other that as of the Effective Date:

               12.5.1 it is not aware of any claim made against it asserting the
invalidity, misuse, unregisterability, unenforceability or non-infringement of
any of its Intellectual Property that is the subject of this Agreement or
challenging its right to use or ownership of any of such Intellectual Property
or making any adverse claim of ownership thereof; and

               12.5.2 it is not aware of any pending or threatened claim or
litigation which alleges that its activities to date relating to the
Intellectual Property that is the subject of this Agreement have violated, or by
conducting its business as currently proposed to be conducted hereunder would
violate, the Intellectual Property rights of any other person or Third Party;
and

               12.5.3 it is not aware of Intellectual Property rights of any
Third Party that, with respect to Athersys' representation and warranty, validly
cover the use of the RAGE-VT Technology or, with respect to 3DP's representation
and warranty, validly cover the use of 3DP's libraries and combinatorial
chemistry technologies, in each case as contemplated under this Agreement.

         12.6  Access to Athersys Cell Lines.
               -----------------------------

               12.6.1 Athersys represents and warrants to 3DP that for the 3DP
Target and Joint Targets, 3DP Lead Compound(s) and Joint Lead Compounds, 3DP
Safety Assessment Compound(s) and Joint Safety Assessment Compounds and 3DP
Development Compounds and Joint Development Compounds, 3DP will have access to
cell lines produced using the RAGE-VT Technology and expressing the 3DP Target
and as required under the applicable Lead Optimization Plans, Pre-Clinical
Development Plans and Clinical Development Plans, the Joint Targets, for 3DP's
internal experimentation within the Research Programs and Development

                                       35
<PAGE>

Programs outlined herein, for those purposes set forth in Sections 3.11 and
4.10.5, as well as the equivalent programs and plans that 3DP develops for 3DP
Lead Compounds, 3DP Safety Assessment Compounds and 3DP Development Compounds.

               12.6.2 3DP represents and warrants to Athersys that 3DP will only
use such cell lines with the 3DP Target and Joint Targets, 3DP Lead Compound(s)
and Joint Lead Compounds, 3DP Safety Assessment Compound(s) and Joint Safety
Assessment Compounds and 3DP Development Compounds and Joint Development
Compounds within the Research Programs and Development Programs outlined herein,
and for a Joint Target, Joint Compound, Joint Lead Compound, Joint Safety
Assessment Compound or Joint Development Compound, only as required under the
applicable Lead Optimization Plan, Pre-Clinical Development Plan and Development
Plan, for those purposes set forth in Sections 3.11 and 4.10.5, as well as the
equivalent programs and plans that 3DP develops for 3DP Lead Compounds, 3DP
Safety Assessment Compounds and 3DP Development Compounds.

         12.7  Access to 3DP Compounds.
               -----------------------

               12.7.1 3DP represents and warrants to Athersys that for the
Athersys Target and Joint Targets, Athersys Lead Compound(s) and Joint Lead
Compounds, Athersys Safety Assessment Compound(s) and Joint Safety Assessment
Compounds and Athersys Development Compound(s) and Joint Development Compounds,
Athersys will have access to selected Compounds from 3DP Probe Library and to
the focused libraries created from the 3DP Synthetically Accessible Library as
required under the applicable Lead Optimization Plans, Pre-Clinical Development
Plans and Clinical Development Plans and for Athersys' internal experimentation
within the Research Programs and Development Programs outlined herein as well as
the equivalent programs and plans that Athersys develops for Athersys Lead
Compounds, Athersys Safety Assessment Compounds and Athersys Development
Compounds.

               12.7.2 Athersys represents and warrants to 3DP that Athersys will
only use such libraries and technology with the Athersys Target and Joint
Targets, Athersys Lead Compound(s) and Joint Lead Compounds, Athersys Safety
Assessment Compound(s) and Joint Safety Assessment Compounds, and Athersys
Development Compound(s) and Joint Development Compounds within the Research
Programs and Development Programs outlined herein and only as required under the
applicable Lead Optimization Plan, Pre-Clinical Development Plan and Clinical
Development Plan as well as the equivalent programs and plans that Athersys
develops for Athersys Lead Compounds, Athersys Safety Assessment Compounds and
Athersys Development Compounds.

         12.8  Disclaimer of Warranties. EXCEPT AS EXPRESSLY SET FORTH IN THIS
               ------------------------
AGREEMENT, NEITHER PARTY MAKES ANY REPRESENTATIONS AND EXTENDS NO WARRANTIES OR
CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED
TO, WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
NON-INFRINGEMENT.

                                   ARTICLE 13
                                 INDEMNIFICATION

                                       36
<PAGE>

         13.1  Indemnification by Athersys. Athersys shall indemnify, defend and
               ---------------------------
hold 3DP, its Affiliates and their permitted contractors and agents, employees,
officers and directors (the "3DP Indemnitees") harmless from and against any and
                             ---------------
all liability, damage, loss, cost or expense (including reasonable attorneys'
fees) arising out of Third Party claims or lawsuits related to (a) Athersys'
performance of its obligations under this Agreement; (b) the manufacture, use or
sale of Products by Athersys and its Affiliates, sublicensees, distributors and
agents; (c) a material breach by Athersys of any of its covenants,
representations or warranties set forth in this Agreement; or (d) claims that
the development or commercialization of any Athersys Target, Athersys Compound,
Athersys Lead Compound, Athersys Safety Assessment Compound, Athersys
Development Compound or Athersys Product infringes the Intellectual Property
rights of a Third Party, except to the extent such claims or suits result from
the material breach of any of the provisions of this Agreement, gross negligence
or willful misconduct of the 3DP Indemnitees. Upon the assertion of any such
claim or suit, the 3DP Indemnitees shall promptly notify Athersys thereof and
Athersys shall appoint counsel reasonably acceptable to the 3DP Indemnitees to
represent the 3DP Indemnitees with respect to any claim or suit for which
indemnification is sought. The 3DP Indemnities shall not settle any such claim
or suit without the prior written consent of Athersys, unless the 3DP
Indemnitees shall have first waived their rights to indemnification hereunder.

         13.2  Indemnification By 3DP. 3DP shall indemnify, defend and hold
               ----------------------
Athersys, its Affiliates and their permitted contractors and agents, employees,
officers and directors (the "Athersys Indemnitees") harmless from and against
                             --------------------
any and all liability, damage, loss, cost or expense (including reasonable
attorneys' fees) arising out of Third Party claims or lawsuits related to (a)
3DP's performance of its obligations under this Agreement; (b) the manufacture,
use or sale of Products by 3DP and its Affiliates, sublicensees, distributors
and agents; (c) a material breach by 3DP of any of its covenants,
representations or warranties set forth in this Agreement; or (d) claims that
the development or commercialization of any 3DP Target, 3DP Compound, 3DP Lead
Compound, 3DP Safety Assessment Compound, 3DP Development Compound or 3DP
Product infringes the Intellectual Property rights of a Third Party, except to
the extent that such claims or suits result from the material breach of any of
the provisions of this Agreement, gross negligence or willful misconduct of the
Athersys Indemnitees. Upon the assertion of any such claim or suit, the Athersys
Indemnitees shall promptly notify 3DP thereof and 3DP shall appoint counsel
reasonably acceptable to the Athersys Indemnitees to represent the Athersys
Indemnitees with respect to any claim or suit for which indemnification is
sought. The Athersys Indemnitees shall not settle any such claim or suit without
the prior written consent of 3DP, unless the Athersys Indemnitees shall have
first waived their rights to indemnification hereunder.

         13.3  Insurance Proceeds. Any indemnification hereunder shall be made
               ------------------
net of any insurance proceeds recovered by the indemnified Party; provided,
however, that if, following the payment to the indemnified Party of any amount
under this ARTICLE 13, such indemnified Party recovers any insurance proceeds in
respect of the claim for which such indemnification payment was made, the
indemnified Party shall promptly pay an amount equal to the amount of such
proceeds (but not exceeding the amount of such indemnification payment) to the
indemnifying Party.

                                       37
<PAGE>

         13.4  Insurance. Each Party shall maintain insurance, including product
               ---------
liability insurance, with respect to its activities hereunder. Such insurance
shall be in such amounts and subject to such deductibles as the Parties may
agree based upon standards prevailing in the industry at the time. Each Party
may satisfy its obligations under this Section through self-insurance to the
same extent.

                                   ARTICLE 14
                              TERM AND TERMINATION

         14.1  Term. The Research Program shall commence upon the Effective
               ----
Date, and, unless all or a portion of the Research Program is extended by mutual
written agreement of the Parties, shall expire as to each Joint Target, the 3DP
Target and the Athersys Target, at the end of its Research Term. The Development
Program under this Agreement shall expire as to each Lead Compound, Safety
Assessment Compound and Development Compound upon expiration of its Development
Term. This Agreement shall terminate in its entirety upon expiration of all
Research Terms and their corresponding periods thereafter set forth in Sections
3.10 and 3.11, all Development Terms and their corresponding periods thereafter
set forth in Sections 4.10.4 and 4.10.5 and Royalty Terms.

         14.2  Extension of Research Program. If the Parties expand the Research
               -----------------------------
Program as provided in Section 3.13, the JSC shall extend the Research Term as
appropriate therefor.

         14.3  Partial Termination. Either Party may, independently of the other
               -------------------
Party and the JSC or JDC, elect to discontinue its funding of Lead Optimization,
Pre-Clinical Development or Clinical Development, or commercialization of a
Joint Lead Compound, Joint Safety Assessment Compound or Joint Development
Compound related to a Joint Target or Joint Product, as applicable, by giving
written notice thereof to the other Party prior to any of the following points
in time (each, an "Opt-Out Point"):
                   -------------

               14.3.1 Initiation of Lead Optimization;

               14.3.2 Initiation of Pre-Clinical Development;

               14.3.3 Initiation of the first Phase I trial;

               14.3.4 Initiation of the first Phase II trial;

               14.3.5 Initiation of the first Phase III trial; or

               14.3.6 Any time after Phase III is completed and all study
reports have been finalized.

         14.4  Breach. The failure by a Party to comply with any of the material
               ------
obligations contained in this Agreement shall entitle the other Party to give
notice to have the default cured. If such default is not cured within sixty (60)
days after the receipt of such notice, or diligent steps are not taken to cure
if by its nature such default could not be cured within sixty (60) days, the
notifying Party shall be entitled, without prejudice to any of its other rights
conferred on it by this Agreement, and in addition to any other remedies that
may be available to it, to terminate

                                       38
<PAGE>

this Agreement with respect to a given Joint Lead Compound, Joint Safety
Assessment Compound, or Joint Development Compound or, depending upon the
materiality of the breach to the entire Agreement, to terminate this Agreement
in its entirety; provided, however, that such right to terminate shall be stayed
in the event that, during such 60-day period, the Party alleged to have been in
default shall have: (a) initiated arbitration in accordance with ARTICLE 15,
below, with respect to the alleged default, and (b) diligently and in good faith
cooperated in the prompt resolution of such arbitration proceedings.

         14.5  Insolvency or Bankruptcy.
               ------------------------

               14.5.1 Either Party may, in addition to any other remedies
available by law or in equity, terminate this Agreement by written notice to the
other Party in the event the latter Party shall have become insolvent or
bankrupt, or shall have an assignment for the benefit of its creditors, or there
shall have been appointed a trustee or receiver of the other Party or for all or
a substantial part of its property or any case or proceeding shall have been
commenced or other action taken by or against the other Party in bankruptcy or
seeking reorganization, liquidation, dissolution, winding-up, arrangement or
readjustment of its debts or any other relief under any bankruptcy, insolvency,
reorganization or other similar act or law of any jurisdiction now or hereafter
in effect, or there shall have been issued a warrant of attachment, execution,
restraint or similar process against any substantial part of the property of the
other Party, and any such event shall have continued for ninety (90) days
undismissed, unbonded and undischarged.

               14.5.2 All rights and licenses granted under or pursuant to this
Agreement by Athersys or 3DP are, and shall otherwise be deemed to be, for
purposes of Section 365(n) of the U.S. Bankruptcy Code, licenses of right to
"Intellectual Property" as defined under Section 101 of the U.S. Bankruptcy
Code. The Parties agree that the Parties as licensees of such rights under this
Agreement, shall retain and may fully exercise all of their rights and elections
under the U.S. Bankruptcy Code. The Parties further agree that, in the event of
the commencement of a bankruptcy proceeding by or against either Party under the
U.S. Bankruptcy Code, the Party hereto which is not a Party to such proceeding
shall be entitled to a complete duplicate of (or complete access to, as
appropriate) any such Intellectual Property and all embodiments or descriptions
of such licensed Intellectual Property, and same, if not already in their
possession, shall be promptly delivered to it (a) upon any such commencement of
a bankruptcy proceeding upon its written request therefor, unless the Party
subject to such proceedings elects to continue to perform all of its obligations
under this Agreement or (b) if not delivered under (a) above, upon the rejection
of this Agreement by or on behalf of the Party subject to such proceeding upon
written request therefor by the nondebtor Party.

         14.6  Survival of Obligations. The termination or expiration of this
               -----------------------
Agreement shall not relieve the Parties of any obligations accruing prior to
such termination, and any such termination shall be without prejudice to the
rights of either Party against the other. The provisions of Sections 3.12.2,
3.12.4, 7.3, 7.5, 12.8, 14.6 and 14.7 and Articles 1, 8, 10, 11, 13, 15 and 16
shall survive any termination of this Agreement.

                                       39
<PAGE>

         14.7  Effects of Termination.
               ----------------------

               14.7.1 If a Party elects to partially terminate this Agreement in
accordance with Section 14.3, then such terminating Party will receive royalties
and a share of the Profits and/or LMPs in accordance with Schedule 5.2;
                                                          ------------
provided, however,[* *]. For the avoidance of doubt, there shall be no limit on
the amount a terminating Party may receive for royalties on Net Sales other than
the Royalty Term.

               14.7.2 If a Party terminates this Agreement pursuant to Section
14.4 or 14.5 between any two of the Opt-Out Points, then such terminated Party
shall be entitled to receive a share of the Profits, LMPs and royalties as set
forth on Schedule 5.2 for the last fully-completed Opt-Out Point prior to the
         ------------
effective date of such termination; provided, however, [* *]. For the avoidance
of doubt, there shall be no limit on the amount a terminated Party may receive
for royalties on Net Sales other than the Royalty Term.

                                   ARTICLE 15
                               DISPUTE RESOLUTION

         15.1  Dispute Resolution Process. Both Parties understand and
               --------------------------
appreciate that their long term mutual interest will be best served by affecting
a rapid and fair resolution of any claims or disputes which may arise out of
services performed under this contract or from any dispute concerning the terms
of this Agreement. Therefore, both Parties agree to use their best efforts to
resolve all such disputes as rapidly as possible on a fair and equitable basis.
Toward this end, both Parties agree to develop and follow a process for
presenting, rapidly assessing, and settling claims on a fair and equitable basis
that takes into account the precise subject and nature of the dispute.

         15.2  Dispute Resolution Panel. If any dispute or claim arising under
               ------------------------
this Agreement cannot be readily resolved by the Parties pursuant to the process
described above, then the Parties agree to refer the matter to a panel
consisting of the Chief Executive Officer of 3DP and the Chief Executive Officer
of Athersys or their designees for review and a non-binding resolution. A copy
of the terms of this Agreement, agreed upon facts (and areas of disagreement),
and concise summary of the basis for each side's contentions will be provided to
both such officers who shall review the same, confer and attempt to reach a
mutual resolution of the issue.

         15.3  Arbitration.
               -----------

               15.3.1 If the matter has not been resolved utilizing the
foregoing process and the Parties are unwilling to accept the non-binding
decision of the dispute resolution panel, either or both Parties may elect to
pursue definitive resolution through binding arbitration, which the Parties
agree to accept in lieu of litigation or other legally available remedies (with
the exception of injunctive relief where such relief is necessary to protect a
Party from irreparable harm pending the outcome of any such arbitration
proceeding). Binding arbitration shall be settled in accordance with the Rules
of the American Arbitration Association by a panel of three arbitrators chosen
in accordance with such Rules. If such dispute relates primarily to Patents
relating to

                                       40
<PAGE>

Products, such arbitrators shall be selected in such a manner to ensure that
they will have sufficient technical expertise and training to handle such a
dispute.

               15.3.2 As set forth in Section 16.14, this Agreement shall be
governed by and construed in accordance with the substantive laws of the State
of Delaware without regard to the conflicts of laws provisions of Delaware. The
arbitration will be held in Wilmington, Delaware. Judgment upon the award
rendered may be entered in any court having jurisdiction and the Parties hereby
consent to the said jurisdiction and venue, and further irrevocably waive any
objection which either Party may have now or hereafter to the laying of venue of
any proceedings in said courts and to any claim that such proceedings have been
brought in an inconvenient forum, and further irrevocably agree that a judgment
or order in any such proceeding shall be conclusive and binding upon the Parties
and may be enforced in the courts of any other jurisdiction.

                                   ARTICLE 16
                            MISCELLANEOUS PROVISIONS

         16.1  Entire Agreement. This Agreement and each of the Schedules hereto
               ----------------
constitute and contain the entire understanding and agreement of the Parties
respecting the subject matter of this Agreement and cancels and supersedes any
all prior negotiations, correspondence, understandings and agreements between
the Parties, whether oral or written, regarding such subject matter.

         16.2  Further Actions. Each Party agrees to execute, acknowledge and
               ---------------
deliver such further instruments and to do all such other acts as may be
necessary or appropriate in order to carry out the purposes and intent of this
Agreement.

         16.3  Binding Effect. This Agreement and the rights granted herein
               --------------
shall be binding upon and shall inure to the benefit of 3DP, Athersys and their
successors and permitted assigns.

         16.4  Assignment. Neither Party shall assign this Agreement without the
               ----------
prior written consent of the other Party; provided, however, that either Party
may assign this Agreement without the prior written consent of the other in
connection with the sale or transfer of substantially all of its assets that
relate to this Agreement, or in the event of its merger or consolidation or
change of control or similar transaction, or to a wholly-owned Affiliate of a
Party. Any permitted assignee shall assume all obligations of its assignor under
this Agreement.

         16.5  No Implied Licenses. No rights to any other patents, know-how or
               -------------------
technical information, or other intellectual property rights, other than as
explicitly identified herein, are granted or deemed granted by this Agreement.
Except as provided in Section 10.4, no right, expressed or implied, is granted
by this Agreement to a Party to use in any manner the name or any other trade
name or trademark of the other Party in connection with the performance of this
Agreement.

         16.6  No Waiver. No waiver, modification or amendment of any provision
               ---------
of this Agreement shall be valid or effective unless made in writing and signed
by a duly authorized officer of each Party. The failure of either Party to
assert a right hereunder or to insist upon

                                       41
<PAGE>

compliance with any term or condition of this Agreement shall not constitute a
waiver of that right or excuse a similar subsequent failure to perform any such
term or condition.

         16.7  Force Majeure. The failure of a Party to perform any obligation
               -------------
under this Agreement by reason of acts of God, acts of governments, riots, wars,
strikes, accidents or deficiencies in materials or transportation or other
causes of a similar magnitude beyond its control shall not be deemed to be a
breach of this Agreement.

         16.8  Independent Contractors. Both Parties are independent contractors
               -----------------------
under this Agreement. Nothing contained in this Agreement is intended nor is to
be construed so as to constitute 3DP or Athersys as partners or joint venturers
with respect to this Agreement. Neither Party shall have any express or implied
right or authority to assume or create any obligations on behalf of or in the
name of the other Party or to bind the other Party to any other contract,
agreement or undertaking with any Third Party.

         16.9  Notices and Deliveries. Any formal notice, request, delivery,
               ----------------------
approval or consent required or permitted to be given under this Agreement shall
be in writing and shall be deemed to have been sufficiently given when it is
received, whether delivered in person, transmitted by facsimile with
contemporaneous confirmation, or delivery by registered letter (or its
equivalent) or delivery by certified overnight courier service, to the Party to
which it is directed at its address shown below or such other address as such
Party shall have last given by notice to the other Parties.

               If to Athersys:                       with a copy to:

               Athersys, Inc.                        Jones, Day, Reavis & Pogue
               3201 Carnegie Avenue                  North Point
               Cleveland, OH  44115-2634             901 Lakeside Avenue
               Fax: (216) 361-9495                   Cleveland, OH 44114-2304
               ATTN:  Chief Executive Officer        ATTN:  Thomas Briggs, Esq.


               If to 3DP:                            with a copy to:

               3-Dimensional Pharmaceuticals, Inc.   Morgan, Lewis & Bockius LLP
               1020 Stony Hill Road, Suite 300       1701 Market Street
               Yardley, PA  19067                    Philadelphia, PA 19103-2921
               Fax: (267) 757-7283
               ATTN: Chief Executive Officer         ATTN:  Edward Lentz, Esq.


         16.10 Public Announcements. The Parties will agree upon the timing and
               --------------------
content of any initial press release, attached hereto as Schedule 16.10, or
other public communications relating to this Agreement and the transactions
contemplated herein.

               16.10.1 Except to the extent already disclosed in that initial
press release or other public communication, no public announcement concerning
the existence or the terms of this

                                       42
<PAGE>

Agreement or concerning the transactions described herein shall be made, either
directly or indirectly, by Athersys or 3DP, except as set forth in Section 10.4,
without first obtaining the approval of the other Party and agreement upon the
nature, text, and timing of such announcement, which approval and agreement
shall not be unreasonably withheld.

               16.10.2 The Party desiring to make any such public announcement
shall provide the other Party with a written copy of the proposed announcement
in sufficient time prior to public release to allow such other Party to comment
upon such announcement, prior to public release.

         16.11 Headings. The captions to the sections and articles in this
               --------
Agreement are not a part of this Agreement, and are included merely for
convenience of reference only and shall not affect its meaning or
interpretation.

         16.12 Severability. If any provision of this Agreement becomes or is
               ------------
declared by a court of competent jurisdiction to be illegal, unenforceable or
void, this Agreement shall continue in full force and effect without said
provision, so long as the Agreement, taking into account said voided
provision(s), continues to provide the Parties with the same practical economic
benefits as the Agreement containing said voided provision(s) did on the
Effective Date. If, after taking into account said voided provision(s), the
Parties are unable to realize the practical economic benefit contemplated on the
Effective Date, the Parties shall negotiate in good faith to amend this
Agreement to reestablish the practical economic benefit provided the Parties on
the Effective Date.

         16.13 No Consequential Damages. IN NO EVENT SHALL EITHER PARTY OR ANY
               ------------------------
OF ITS RESPECTIVE AFFILIATES BE LIABLE TO THE OTHER PARTY OR ANY OF ITS
AFFILIATES FOR SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES, WHETHER
IN CONTRACT, WARRANTY, TORT, NEGLIGENCE, STRICT LIABILITY OR OTHERWISE,
INCLUDING, BUT NOT LIMITED TO, LOSS OF PROFITS OR REVENUE, OR CLAIMS OF
CUSTOMERS OF ANY OF THEM OR OTHER THIRD PARTIES FOR SUCH OR OTHER DAMAGES.

         16.14 Applicable Law. This Agreement shall be governed by and
               --------------
interpreted in accordance with the laws of the State of Delaware without
reference to its conflicts of laws provisions.

         16.15 Counterparts. This Agreement may be executed in counterparts, or
               ------------
facsimile versions, each of which shall be deemed to be an original, and both of
which together shall be deemed to be one and the same agreement.

                            [Signature Page Follows]

                                       43
<PAGE>

         IN WITNESS WHEREOF, the Parties have caused this Agreement to be
executed by their respective duly authorized officers as of the Effective Date,
each copy of which shall for all purposes be deemed to be an original.


                                       ATHERSYS, INC.


                                       By:______________________________________
                                          Name:
                                          Title:


                                       3-DIMENSIONAL PHARMACEUTICALS, INC.


                                       By:______________________________________
                                          Name:
                                          Title:


       SIGNATURE PAGE TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

                                  Schedule 1.10

                                Candidate Targets
                                -----------------


I.       Joint Targets
         -------------

         [*                                   *].

II.      3DP Target
         ----------

         [*                                   *].

III.     Athersys Target
         ---------------

         [*                                   *].


                                  SCHEDULE 1.10
               TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

                                 Schedule 1.14
                                 -------------
                             Compound and Work Flow
                             ----------------------


     Compounds                                                   Targets


                                Lead Generation
                                                                 Research
                                                                 Program
                                                                  (ends)


                                     Lead                      Development
                                   Compound                      Program
                                                                 (begins)


                               Lead Optimization


        JSC                    Safety Assessment
      (ends)                       Compound


        JDC                Pre-Clinical Development
     (begins)


                                  Development
                                   Compound


                             Clinical Development
         (IND, Phases I,II,III (and IV), NDA and Regulatory Approval)


                                    Product



                                  SCHEDULE 1.14
               TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

                                  Schedule 1.30
                                  -------------


[* 1 entire page has been omitted pursuant to a confidential treatment request*]


                                  SCHEDULE 1.30
               TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

                                  Schedule 3.5
                                  ------------

  [* 2 pages have been omitted pursuant to a confidential treatment request *]


                                  SCHEDULE 3.5
               TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

                                  Schedule 3.6

[* 1 entire page has been omitted pursuant to a confidential treatment request*]


                                  SCHEDULE 3.6
               TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

                                  Schedule 5.2

                    Revenue Sharing with Discontinuing Party
                    ----------------------------------------

The outline below illustrates revenue sharing in the event a Party opts-out as
provided in Section 4.9. [* *].

1.1      If the Discontinuing Party discontinues funding prior to Lead
Optimization, and

         1.1.1  if the Funding Party licenses, assigns or sells the former Joint
Lead Compound prior to initiation of Lead Optimization, then the Funding Party
shall pay to the Discontinuing Party [* *] of LMPs received from such
outlicensing, assignment or sale as well as [* *] of any royalty received by the
Funding Party on Net Sales by its Third Party Licensee(s) of Product comprising
the former Joint Lead Compound. [* *];

         1.1.2  if the Funding Party licenses, assigns or sells the former Joint
Lead Compound during Lead Optimization, then the Funding Party shall pay to the
Discontinuing Party [* *] of LMP received from such outlicensing, assignment or
sale;

         1.1.3  if the Funding Party licenses, assigns or sells the former Joint
Lead Compound during Pre-Clinical Development, then the Funding Party shall pay
to the Discontinuing Party [* *] of LMP received from such outlicensing,
assignment or sale;

         1.1.4  if the Funding Party licenses, assigns or sells the former Joint
Lead Compound during Phase I, then the Funding Party shall pay to the
Discontinuing Party [* *] of LMP received from such outlicensing, assignment or
sale;

         1.1.5  if the Funding Party licenses, assigns or sells the former Joint
Lead Compound during Phase II, then the Funding Party shall pay to the
Discontinuing Party [* *] of LMP received from such outlicensing, assignment or
sale;

         1.1.6  if the Funding Party licenses, assigns or sells the former Joint
Lead Compound during or after Phase III, then the Funding Party shall pay to the
Discontinuing Party [* *] of LMP received from such outlicensing, assignment or
sale;

         1.1.7  in addition to any amounts the Funding Party may owe to the
Discontinuing Party under the foregoing Sections 1.1.2 - 1.1.6 of this Schedule
                                                                       --------
5.2, the Funding Party shall pay to the Discontinuing Party a royalty equal to
---
[* *] of all Net Sales (whether by Funding Party or its Third Party Licensee(s))
of Product comprising the former Joint Lead Compound; and


                                  SCHEDULE 5.2
               TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

         1.1.8  with respect to each license, assignment or sale, the amounts
under Sections 1.1.1 - 1.1.6 are mutually exclusive such that the Funding Party
shall only owe to the Discontinuing Party the first of such amounts to occur and
no other such amounts for the same transaction and as exemplified in Schedule
                                                                     --------
5.3.7. Any royalty obligation will last for the duration of the Royalty Term.
-----

1.2      If the Discontinuing Party discontinues funding prior to Pre-Clinical
Development, and

         1.2.1  if the Funding Party licenses, assigns or sells the former Joint
Safety Assessment Compound prior to initiation of Pre-Clinical Development, then
the Funding Party shall pay to the Discontinuing Party [* *] of LMPs received
from such outlicensing, assignment or sale as well as [* *] of any royalty
received by the Funding Party on Net Sales by its Third Party Licensee(s) of
Product comprising the former Joint Safety Assessment Compound. [* *];

         1.2.2  if the Funding Party licenses, assigns or sells the former Joint
Safety Assessment Compound during Pre-Clinical Development, then the Funding
Party shall pay to the Discontinuing Party [* *] of LMP received from such
outlicensing, assignment or sale;

         1.2.3  if the Funding Party licenses, assigns or sells the former Joint
Safety Assessment Compound during Phase I, then the Funding Party shall pay to
the Discontinuing Party [* *] of LMP received from such outlicensing, assignment
or sale;

         1.2.4  if the Funding Party licenses, assigns or sells the former Joint
Safety Assessment Compound during Phase II, then the Funding Party shall pay to
the Discontinuing Party [* *] of LMP received from such outlicensing, assignment
or sale;

         1.2.5  if the Funding Party licenses, assigns or sells the former Joint
Safety Assessment Compound during or after Phase III, then the Funding Party
shall pay to the Discontinuing Party [* *] of LMP received from such
outlicensing, assignment or sale; and

         1.2.6  in addition to any amounts the Funding Party may owe to the
Discontinuing Party under the foregoing Sections 1.2.2 - 1.2.5 of this Schedule
                                                                       --------
5.2, the Funding Party shall pay to the Discontinuing Party a royalty equal to
---
[* *] of all Net Sales (whether by Funding Party or its Third Party Licensee(s))
of Product comprising the former Joint Safety Assessment Compound; and

         1.2.7  with respect to each license, assignment or sale, the amounts
under Sections 1.2.1 - 1.2.5 are mutually exclusive such that the Funding Party
shall only owe to the Discontinuing Party the first of such amounts to occur and
no other such amounts for the same transaction and as exemplified in Schedule
                                                                     --------
5.3.7. Any royalty obligation will last for the duration of the Royalty Term.
-----

1.3      If the Discontinuing Party discontinues funding prior to initiation of
a Phase I trial

                                  SCHEDULE 5.2
               TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

         1.3.1  if the Funding Party licenses, assigns or sells the former Joint
Development Compound prior to initiation of Phase I, then the Funding Party
shall pay to the Discontinuing Party [* *] of LMPs received from such
outlicensing, assignment or sale as well as [* *] of any royalty received by the
Funding Party on Net Sales by its Third Party Licensee(s) of Product comprising
the former Joint Development Compound. [* *];

         1.3.2  if the Funding Party licenses, assigns or sells the former Joint
Development Compound during Phase I, then the Funding Party shall pay to the
Discontinuing Party [* *] of LMP received from such outlicensing, assignment or
sale

         1.3.3  if the Funding Party licenses, assigns or sells the former Joint
Development Compound during Phase II, then the Funding Party shall pay to the
Discontinuing Party [* *] of LMP received from such outlicensing, assignment or
sale;

         1.3.4  if the Funding Party licenses, assigns or sells the former Joint
Development Compound during or after Phase III, then the Funding Party shall pay
to the Discontinuing Party [* *] of LMP received from such outlicensing,
assignment or sale; and

         1.3.5  in addition to any amounts the Funding Party may owe to the
Discontinuing Party under the foregoing Sections 1.3.2 - 1.3.4 of this Schedule
                                                                       --------
5.2, the Funding Party shall pay to the Discontinuing Party a royalty equal to
---
[* *] of all Net Sales (whether by Funding Party or its Third Party Licensee(s))
of Product comprising the former Joint Development Compound; and

         1.3.6  with respect to each license, assignment or sale, the amounts
under Sections 1.3.1 - 1.3.4 are mutually exclusive such that the Funding Party
shall only owe to the Discontinuing Party the first of such amounts to occur and
no other such amounts for the same transaction and as exemplified in Schedule
                                                                     --------
5.3.7. Any royalty obligation will last for the duration of the Royalty Term.
-----
1.4      If the Discontinuing Party discontinues funding prior to initiation of
a Phase II trial

         1.4.1  if the Funding Party licenses, assigns or sells the former Joint
Development Compound prior to initiation of Phase II, then the Funding Party
shall pay to the Discontinuing Party [* *] of LMPs received from such
outlicensing, assignment or sale as well as [* *]of any royalty received by the
Funding Party on Net Sales by its Third Party Licensee(s) of Product comprising
the former Joint Development Compound. [* *];

         1.4.2  if the Funding Party licenses, assigns or sells the former Joint
Development Compound during Phase II, then the Funding Party shall pay to the
Discontinuing Party [* *] of LMP received from such outlicensing, assignment or
sale;

                                  SCHEDULE 5.2
               TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

         1.4.3  if the Funding Party licenses, assigns or sells the former Joint
Development Compound during or after Phase III, then the Funding Party shall pay
to the Discontinuing Party [* *] of LMP received from such outlicensing,
assignment or sale; and

         1.4.4  in addition to any amounts the Funding Party may owe to the
Discontinuing Party under the foregoing Sections 1.4.2 - 1.4.3 of this Schedule
                                                                       --------
5.2, the Funding Party shall pay to the Discontinuing Party a royalty equal to
---
[* *] of all Net Sales (whether by Funding Party or its Third Party Licensee(s))
of Product comprising the former Joint Development Compound; and

         1.4.5  with respect to each license, assignment or sale, the amounts
under Sections 1.4.1 - 1.4.3 are mutually exclusive such that the Funding Party
shall only owe to the Discontinuing Party the first of such amounts to occur and
no other such amounts for the same transaction and as exemplified in Schedule
                                                                     --------
5.3.7. Any royalty obligation will last for the duration of the Royalty Term.
-----
1.5      If the Discontinuing Party discontinues funding prior to initiation of
a Phase III trial

         1.5.1  if the Funding Party licenses, assigns or sells the former Joint
Development Compound prior to initiation of Phase III, then the Funding Party
shall pay to the Discontinuing Party [* *] of LMPs received from such
outlicensing, assignment or sale as well as [* *] of any royalty received by the
Funding Party on Net Sales by its Third Party Licensee(s) of Product comprising
the former Joint Development Compound. [* *];

         1.5.2  if the Funding Party licenses, assigns or sells the former Joint
Development Compound during or after Phase III, then the Funding Party shall pay
to the Discontinuing Party [*    *] of LMP received from such outlicensing,
assignment or sale; and

         1.5.3  in addition to any amounts the Funding Party may owe to the
Discontinuing Party under the foregoing Section 1.5.2 of this Schedule 5.2, the
                                                              ------------
Funding Party shall pay to the Discontinuing Party a royalty equal to [* *] of
all Net Sales (whether by Funding Party or its Third Party Licensee(s)) of
Product comprising the former Joint Development Compound. Any royalty obligation
will last for the duration of the Royalty Term.

2.1      If the Discontinuing Party discontinues funding:

         2.1.1  prior to Lead Optimization, and the Funding Party fully funds
Lead Optimization, Pre-Clinical Development and Clinical Development and
commercialization, then the Funding Party shall pay to the Discontinuing Party
[* *] of its Profits and a royalty equal to [* *] of the Net Sales of such
Product comprising the former Joint Lead Compound;

         2.1.2  prior to Pre-Clinical Development and the Funding Party fully
funds Pre-Clinical Development and Clinical Development and commercialization,
then the Funding Party shall pay

                                  SCHEDULE 5.2
               TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

to the Discontinuing Party [* *] of its Profits and a royalty equal to [* *] of
the Net Sales of such Product comprising the former Joint Safety Assessment
Compound;

         2.1.3  prior to Phase I and the Funding Party fully funds Clinical
Development and commercialization, then the Funding Party shall pay
to the Discontinuing Party [* *] of its Profits and a royalty equal to [* *] of
the Net Sales of such Product comprising the former Joint Development Compound;

         2.1.4  prior to Phase II and the Funding Party fully funds Phase II and
Phase III Clinical Development and commercialization, then the Funding Party
shall pay to the Discontinuing Party [* *] of its Profits and a royalty equal to
[* *] of the Net Sales of such Product comprising the former Joint Development
Compound; and

         2.1.5  prior to Phase III and the Funding Party fully funds Phase III
Clinical Development and commercialization, then the Funding Party shall pay to
the Discontinuing Party [* *] of its Profits and a royalty equal to [* *] of the
Net Sales of such Product comprising the former Joint Development Compound.

         2.1.6  With respect to each license, assignment or sale, the amounts
under Sections 2.1.1 - 2.1.5 are mutually exclusive such that the Funding Party
shall only owe to the Discontinuing Party the first of such amounts to occur and
no other such amounts for the same transaction under such Sections or under
Sections 1.1.1 - 1.5.3 of this Schedule 5.2 and as exemplified in Schedule
                               ------------                       --------
5.3.7. Any royalty obligation will last for the duration of the Royalty Term.
-----

                                  SCHEDULE 5.2
               TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

                                 Schedule 5.3.7
                                 --------------

         Examples of Mutually Exclusive Transactions Concerning Amounts
             Payable Under Schedule 5.2, Section 5.3 and Section 5.4
             -------------------------------------------------------

Illustrative Example 1:
-----------------------

Athersys opts out at the initiation of Pre-Clinical Development and 3DP elects
to continue as a Funding Party. 3DP completes Pre-Clinical Development
successfully developing a Development Compound and then:

Action: 3DP licenses during Phase I to Third Party X for the territory of the
------
United States, Canada and Mexico.

         Result: Under Section 1.2.3 of Schedule 5.2, 3DP pays to Athersys [* *]
         ------
         of the LMP received from the licensing and, under Section 1.2.6 of
         Schedule 5.2, [* *] of Net Sales of Products comprising the Development
         Compound by Third Party X in the United States, Canada and Mexico, but
         no other fees under Schedule 5.2 in connection with the transaction.

Action: 3DP enters into a co-development and co-commercialization agreement
------
during Phase II with Third Party Y for the territory of Europe and agrees to
sell the rights in the Product in Europe should it be approved therein.

         Result: Under Section 1.2.4, 3DP pays Athersys [* *] of the LMP
         ------
         received from the transaction, and, under Section 1.2.6 of Schedule
         5.2, [* *] of Net Sales of Products comprising the Development Compound
         by Third Party Y in Europe.

Action: Subsequently, 3DP sells the co-commercialization rights to the Product
------
in Europe to Third Party Y after regulatory approval.

         Result: Notwithstanding the earlier transaction with Third Party Y
         ------
         because the sale of rights was pursuant to a different transaction than
         the earlier license to Third Party Y, under Section 1.2.5 of Schedule
         5.2, 3DP would pay Athersys [* *] of the LMP received from the sale
         and, under Section 1.2.6 of Schedule 5.2, [* *] of Net Sales of
         Products comprising the Development Compound by Third Party Y in
         Europe, but no other fees under Schedule 5.2 in connection with the
         sale.

Illustrative Example 2/1/:
-------------------------

Action: Athersys licenses an Athersys Product to Company A for Territory M for X
dollars.


                                 SCHEDULE 5.3.7
               TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

         Result: Athersys pays to 3DP [* *] of X (depending on which of 5.3.2,
         ------
         5.3.3, 5.3.4, 5.3.5, and 5.3.6 apply) and also pays to 3DP a royalty in
         the amount of [* *] of the Net Sales by Company A in Territory M.

Action: Subsequently, Athersys licenses rights in the same Product to Company A
------
for Territory N for Y Dollars.

         Result: Athersys pays [* *] of Y (depending on which of 5.3.2, 5.3.3,
         ------
         5.3.4, 5.3.5, and 5.3.6 apply) and also pays to 3DP a royalty in the
         amount of [* *] of the Net Sales by Company A in Territory N.

Action: Athersys retains right in Territory O, and subsequently, Athersys
------
markets the same Product in Territory O.

         Result: Athersys pays to 3DP [* *] of its Profits on the sale of the
         ------
         Athersys Product and also pays to 3DP a royalty in the amount of [* *]
         of its Net Sales, as provided in Section 5.3.1.

Illustrative Example 3/2/:
-------------------------

Action: 3DP licenses a 3DP Product to Company A worldwide for X dollars,
------
retaining a co-marketing right in Territory M.

         Result: 3DP pays to Athersys [* *] of X (depending on which of 5.4.2,
         ------
         5.4.3, 5.4.4, 5.4.5, and 5.4.6 apply) and also pays to Athersys a
         royalty in the amount of [* *] of the Net Sales by Company A.

Action: In accordance with the terms of the agreement with Company A, 3DP
------
co-markets the same 3DP Product in Territory M.

         Result: 3DP pays to Athersys [* *] of its Profits on the sale of the
         ------
         3DP Product and also pays to Athersys a royalty in the amount of [* *]
         of its Net Sales in Territory M, as provided in Section 5.4.1.

Illustrative Example 4/1/:
-------------------------

Action: Athersys licenses an Athersys Product to Company A for Indication M for
------
X dollars.

         Result: Athersys pays to 3DP [* *] of X (depending on which of 5.3.2,
         ------
         5.3.3, 5.3.4, 5.3.5, and 5.3.6 apply) and also pays to 3DP a royalty in
         the amount of [* *] of the Net Sales by Company A for Indication M.

Action: Subsequently, Athersys licenses rights in the same Athersys Product to
------
Company B for Indication N for Y Dollars.

                                 SCHEDULE 5.3.7
               TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

         Result: Athersys pays to 3DP [* *] of Y (depending on which of 5.3.2,
         5.3.3, 5.3.4, 5.3.5, and 5.3.6 apply) and also pays to 3DP a royalty in
         the amount of [* *] of the Net Sales by Company B for Indication N.

Action: Subsequently, Athersys agrees to co-promote with Company A the same
------
Athersys Product for Indication O in consideration for an up-front payment (Z
Dollars) and a share of the combined Athersys-Company A profits based on the
number of details provided by Athersys.

         Result: Athersys pays to 3DP [* *] of its share of Profits on the
         ------
         co-promotion of the Athersys Product for Indication O and also pays to
         3DP a royalty in the amount of [* *] of the Net Sales for Indication O,
         as provided in Section 5.3.1. In addition, Athersys pays to 3DP [* *]
         of Z (depending on which of 5.3.2, 5.3.3, 5.3.4, 5.3.5, and 5.3.6
         apply).

Illustrative Example 5/2/:
-------------------------

Action: 3DP licenses a 3DP Product to Company A worldwide for X dollars.
------

         Result: 3DP pays to Athersys [* *] of X (depending on which of 5.4.2,
         5.4.3, 5.4.4, 5.4.5, and 5.4.6 apply) and also pays to Athersys a
         royalty in the amount of [* *] of the Net Sales by Company A.

Action: 3DP subsequently licenses a 3DP Product line-extension (e.g., new
------
formulation) to Company A worldwide for Y dollars.

         Result: 3DP pays to Athersys [* *] of Y (depending on which of 5.4.2,
         5.4.3, 5.4.4, 5.4.5, and 5.4.6 apply) and also pays to Athersys a
         royalty in the amount of [* *] of the Net Sales by Company A of the 3DP
         Product line-extension.

Notes:
------

/1/      For purposes of illustrative examples 2 and 4, "Athersys Product," does
not include a Product developed against a formerly Joint Target. If the Athersys
Product used in the example was formerly developed against a Joint Target, then
Section 5.2 and Schedule 5.2 would apply.

/2/      For purposes of illustrative examples 3 and 5, "3DP Product," does not
include a Product developed against a formerly Joint Target. If the 3DP Product
used in the example was formerly developed against a Joint Target, then Section
5.2 and Schedule 5.2 would apply.

                                 SCHEDULE 5.3.7
               TO COLLABORATIVE RESEARCH AND DEVELOPMENT AGREEMENT
<PAGE>

<TABLE>
<CAPTION>

                                 Schedule 16.10

                                  Press Release
                                  -------------


<S>                              <C>                                     <C>                            <C>
Athersys, Inc.                   3-Dimensional Pharmaceuticals           Media Inquiries                Investor Inquiries
--------------                   -----------------------------           ---------------                ------------------
Kathryn Garvey                   Scott Horvitz                           Noonan/Russo                   Rx Communications
Director of Strategic            VP, Finance and Administration          Glenn Silver                   Melody Carey
Planning & Investor Relations    267-757-7208                            212-696-4455, ext. 271         917-322-2571
216 431-9900 ext. 223            horvitz@3dp.com                         g.silver@noonanrusso.com       mcarey@rxir.com
ir@athersys.com                  ---------------                         ----------------------------------------------
---------------

</TABLE>

FOR IMMEDIATE RELEASE- DRAFT dated October 24


ATHERSYS AND 3-DIMENSIONAL PHARMACEUTICALS FORM
DRUG DISCOVERY AND DEVELOPMENT COLLABORATION
--------------------------------------------

Cleveland, Ohio and Yardley, Pa, October XX, 2001 - Athersys, Inc. and
3-Dimensional Pharmaceuticals Inc. (Nasdaq: DDDP) today announced a
collaboration to discover, develop and commercialize novel, small molecule
pharmaceuticals by screening against therapeutically relevant drug targets
derived from the G-Protein Coupled Receptor (GPCR) family of proteins. This
collaboration combines Athersys' functional genomics expertise with
3-Dimensional Pharmaceutical's (3DP) small molecule drug development
capabilities for rapid drug identification and optimization of drug candidates.

Under the terms of the agreement, the companies will jointly select a number of
biologically validated targets having commercial or therapeutic value to be
included in the collaboration. Certain small molecule drug candidates identified
from the collaboration will be jointly developed, with the companies sharing
future development costs and commercialization rights, while others will be
retained exclusively by each of the parties for future development and
commercialization.

Athersys will employ its proprietary RAGE (Random Activation of Gene
Expression(TM)) technology platform to provide the collaboration access to cell
lines that express the selected drug targets. Athersys will use the cell lines
to develop screens for drug discovery and screen compounds using 3DP's
DiscoverWorks(R) platform. 3DP will employ its DiscoverWorks(R) platform to
identify and optimize lead compounds active against the validated targets. 3DP's
technologies can be applied to virtually any disease target, and are used to
produce small molecule compounds suitable for drug development in a more timely
and cost-effective manner and with a higher probability of success than
conventional methods.

"This collaboration combines two powerful drug discovery and development
technologies, making it possible for Athersys and 3DP to rapidly discover and
develop small molecule compounds against the biologically validated GPCR targets
that Athersys and 3DP select for development," commented Gil
<PAGE>

Van Bokkelen, Ph.D., Chairman, President and Chief Executive Officer of
Athersys. "This marks another important milestone for Athersys as we continue to
expand our drug development capabilities by establishing strategic partnerships
with companies that have developed highly complementary technology platforms."

"We see this collaboration as a highly synergistic combination of strong biology
and chemistry capabilities that will quickly achieve positive results," said
David C. U'Prichard, Ph.D., Chief Executive Officer of 3DP. "Access to
proprietary, validated targets for drug discovery and development is a key
objective of 3DP and we are very pleased to enter into this collaboration with
Athersys."

3DP (http://www.3dp.com) is an integrated bio-pharmaceuticals company dedicated
to revolutionizing small molecule drug discovery and development. 3DP's
proprietary platform, DiscoverWorks(R), can be applied to virtually any
potential drug target. It produces drug candidates suitable for faster
development, with fewer resources and a higher probability of success than using
conventional drug discovery methods. 3DP is developing its own drug pipeline and
collaborates with other pharmaceutical companies in discovery and development.

Athersys is a functional genomics and biopharmaceutical company engaged in the
development, application and commercialization of novel gene expression tools
and therapeutic products. The company's research and development programs are
focused on its two proprietary platform technologies: RAGE (Random Activation of
Gene Expression(TM)) and SMC(TM) (Synthetic Microchromosome(TM)) vector system.
RAGE is a novel gene expression system that provides the unique ability to
produce protein from virtually every gene in the human genome, without requiring
the cloning of individual genes or use of cDNA libraries. RAGE greatly
accelerates the identification and validation of novel drug targets by enabling
the direct correlation of a disease process or characteristic with expression of
a specific protein. As a result, RAGE has powerful applications in functional
genomics; the generation of validated drug targets; discovery of novel antibody
drug targets; structural proteomics and rational drug design; and the production
of protein therapeutics. Athersys is developing novel therapeutic products based
on its proprietary technologies, through partnerships and internal research and
development programs. This press release and further information on Athersys,
Inc. can be found on the World Wide Web at: www.athersys.com.
                                            -----------------

# # #

For Athersys: Statements herein that are not descriptions of historical facts
are forward-looking and subject to risk and uncertainties. Actual results could
differ materially from those currently anticipated due to a number of factors,
including risks relating to the early stage of products under development;
uncertainties related to patent protection; uncertainties relating to clinical
trials; dependence on third parties, including strategic partners, collaborators
and key personnel; and risks relating to the development and commercialization,
if any, of Athersys' proposed products (such as effectiveness of our products,
marketing, manufacturing, safety, regulatory, patent or product liability,
supply, competition and other risks).

For 3DP: Statements in this press release that are not strictly historical are
"forward-looking" statements which involve a high degree of risk and
uncertainty. Such statements are only predictions, and the actual events of
results may differ materially from those projected in such forward-looking
statements. Factors that could cause or contribute to differences include, but
are not limited to, risks associated with our new and uncertain technologies,
clinical trials
<PAGE>

and product development, the long and arduous process of obtaining regulatory
approval, our dependence on existing strategic alliances and new collaborations,
our dependence on patents and proprietary rights, our ability to protect and
enforce our patents and proprietary rights, the development and availability of
competitive products or technologies, our ability to attract and retain talented
employees and our ability to manage our expansion as a company increasingly
focused on internal product research and development.