CONFIDENTIAL MATERIALS OMITTED AND FILED SEPARATELY WITH THE
         SECURITIES AND EXCHANGE COMMISSION. ASTERISKS DENOTE OMISSIONS.









                AMENDED AND RESTATED PSMA/PSMP LICENSE AGREEMENT


                                  BY AND AMONG


                        PROGENICS PHARMACEUTICALS, INC.,

                               CYTOGEN CORPORATION


                                       AND


                          PSMA DEVELOPMENT COMPANY LLC



                              Dated April 20, 2006








<PAGE>


                                TABLE OF CONTENTS

                                                                            PAGE

1.    DEFINITIONS.............................................................2

2.    REPRESENTATIONS AND WARRANTIES..........................................8

      2.1    By the LLC.......................................................8

      2.2    By CYTOGEN.......................................................9

      2.3    By Progenics....................................................12

      2.4    By All Parties..................................................13

3.    LICENSES...............................................................13

      3.1    Grant by CYTOGEN................................................13

      3.2    Sublicenses.....................................................13

      3.3    Guarantee of Performance of Sublicensee.........................13

      3.4    Cure of Breach by Sublicensee...................................14

      3.5    [**]............................................................14

      3.6    Reservation of Rights...........................................15

      3.7    No Other Rights.................................................15

      3.8    Competition Not Prohibited......................................15

4.    CERTAIN COVENANTS......................................................15

      4.1    No Waivers or Grant of Further Rights...........................15

      4.2    Summary Reports.................................................15

      4.3    Breach of SKICR Agreement.......................................15

      4.4    Notices under the SKICR Agreement...............................16

      4.5    Compliance with Terms of the SKICR Agreement; Assignment........16

      4.6    Termination of Services Agreement...............................16

5.    ROYALTIES AND OTHER PAYMENTS...........................................16

      5.1    Milestone Payments..............................................16

      5.2    Royalties.......................................................17

      5.3    Royalty Buydown.................................................18

      5.4    Reduction of Royalties if Third Party License Required..........19

      5.5    Payments Associated with Existing Third Party Agreements........19

      5.6    Other Products..................................................19


                                       i
<PAGE>


6.    PATENT PROSECUTION AND MAINTENANCE, ETC................................19

      6.1    Prosecution and Maintenance.....................................19

      6.2    Disclosure Regarding Patent Activities..........................20

7.    REPORTS AND ROYALTY PAYMENTS; BOOKS AND RECORDS........................20

      7.1    Reports.........................................................20

      7.2    Royalty Payments................................................21

      7.3    Calculation of Royalties and Other Payments.....................21

      7.4    Currency Control Restrictions...................................21

      7.5    Books and Records...............................................21

8.    TAXATION OF PAYMENTS...................................................22

9.    PRODUCT LIABILITY DISCLAIMERS..........................................22

      9.1    Product Liability Disclaimer by Progenics.......................22

      9.2    Product Liability Disclaimer by CYTOGEN.........................22

      9.3    Product Liability Disclaimer by the LLC.........................22

10.   INDEMNIFICATION AND INFRINGEMENT.......................................22

      10.1   Indemnification.................................................22

      10.2   Infringement of Licensed CYTOGEN Patents........................23

      10.3   Procedure.......................................................23

11.   TERM AND TERMINATION...................................................24

      11.1   Term............................................................24

      11.2   Termination.....................................................24

      11.3   Accrued Rights and Obligations..................................25

12.   EFFECT OF TERMINATION ON SUBLICENSEE...................................26

13.   EXPORT LICENSES........................................................26

14.   MISCELLANEOUS PROVISIONS...............................................26

      14.1   Assignability, Etc..............................................26

      14.2   Notices.........................................................26

      14.3   Independent Contractors.........................................27

      14.4   Counterparts....................................................27

      14.5   Entire Understanding............................................27

      14.6   Headings........................................................28

      14.7   No Implied Rights...............................................28

      14.8   No Waiver.......................................................28


                                       ii
<PAGE>


      14.9   Publicity.......................................................28

      14.10  Promotion and Advertising.......................................29

      14.11  Arbitration.....................................................29

      14.12  Confidentiality.................................................29

      14.13  No Third Party Beneficiaries....................................30

      14.14  Governing Law...................................................31

      14.15  SKICR Agreement.................................................31




                                       iii
<PAGE>


                AMENDED AND RESTATED PSMA/PSMP LICENSE AGREEMENT

     THIS AMENDED AND RESTATED  PSMA/PSMP LICENSE AGREEMENT (this  "Agreement"),
                                                                    ---------
dated April 20, 2006, is made by and among  Progenics  Pharmaceuticals,  Inc., a
Delaware  corporation  having  its place of  business  at 777 Old Saw Mill River
Road,  Tarrytown,  NY  10591  ("Progenics"),  CYTOGEN  Corporation,  a  Delaware
                                ---------
corporation  having its place of  business at 650  College  Road East,  CN 5308,
Princeton,  NJ 08540 ("CYTOGEN"),  and PSMA Development  Company LLC, a Delaware
                       -------
limited  liability company having its principal place of business at 777 Old Saw
Mill River Road, Tarrytown, NY 10591 (the "LLC"). Progenics, CYTOGEN and the LLC
                                           ---
may each be referred to herein individually as a "Party" and collectively as the
"Parties".

     WHEREAS,  Progenics and CYTOGEN  established a collaboration  to pursue the
development and  commercialization  of  immunotherapeutic  products and services
based  on PSMA  and/or  PSMP  and,  in order to  implement  such  collaboration,
Progenics  and CYTOGEN  caused the LLC to be organized and each became the owner
of 50% of the outstanding ownership interests thereof;

     WHEREAS, in furtherance of the collaboration, each of Progenics and CYTOGEN
granted rights to the LLC, pursuant to the PSMA/PSMP License Agreement,  entered
into by and among the LLC,  Progenics  and CYTOGEN (the  "Original  Agreement"),
                                                          -------------------
dated as of June 15, 1999, with respect to intellectual property rights owned or
thereafter  acquired  by  Progenics  or  CYTOGEN  in the Field  (as  hereinafter
defined);

     WHEREAS,  CYTOGEN  had  previously  granted  to  Prostagen  Corporation,  a
Delaware  corporation  ("Prostagen"),  an  exclusive  license to certain  rights
                         ---------
related to PSMA  pursuant to a PSMA  Therapeutics  Sublicense  Agreement,  dated
December  9,  1996,  by  and  between  CYTOGEN  and  Prostagen  (the  "Prostagen
                                                                       ---------
Agreement");
---------

     WHEREAS,  Prostagen had  previously  granted to Northwest  Clinicals LLC, a
Washington  limited  liability  company  ("NWC"),  an  exclusive  sublicense  to
                                           ---
produce,  process or otherwise  manufacture and sell PSMA and PSMP pursuant to a
PSMA  Production  Sublicense  Agreement,  dated as of July 16,  1997  (the  "NWC
                                                                             ---
Agreement"), which has been terminated;
---------

     WHEREAS,  prior to the formation of the LLC,  CYTOGEN  acquired 100% of the
outstanding equity interests in Prostagen,  and CYTOGEN and Prostagen terminated
the Prostagen Agreement to the extent of the Field;

     WHEREAS,  in  order  to  pursue  the  research  and  development   programs
contemplated  by  the  above-referenced   collaboration  between  Progenics  and
CYTOGEN, Progenics,  CYTOGEN and the LLC entered into a Services Agreement dated
June 15, 1999,  pursuant to which Progenics  agreed to perform certain  research
and development services (the "Services Agreement");
                               ------------------

     WHEREAS,  simultaneously with the execution and delivery of this Agreement,
Progenics  has  purchased  all of  CYTOGEN's  interest in the LLC by way of that
certain Membership  Interest Purchase  Agreement,  dated the date hereof, by and
between Progenics and


                                       1
<PAGE>


CYTOGEN  (the  "Purchase  Agreement"),  and the Parties have agreed to amend and
                -------------------
restate the Original  Agreement as set forth herein (as so amended and restated,
this "Agreement").
      ---------

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

     1.    DEFINITIONS.  For  the  purposes  of  this  Agreement,  the following
           -----------
terms,  whether  used in the  singular  or  plural,  shall  have  the  following
meanings:

           AFFILIATE.  The term "Affiliate" shall mean any Person,  corporation,
                                 ---------
company, partnership, joint venture and/or firm which controls, is controlled by
or is under  common  control  with, a Party.  For  purposes of this  definition,
"control" shall mean (a) in the case of corporate  entities,  direct or indirect
ownership of at least 50% of the stock or participating  shares entitled to vote
for the election of directors,  and (b) in the case of  non-corporate  entities,
direct or indirect  ownership  of at least 50% of the equity  interest  with the
power to direct the management and policies of such non-corporate entity.

           AGREEMENT.  The term "Agreement" shall have the  meaning set forth in
                                 ---------
the recitals.

           AMENDMENT EFFECTIVE DATE.  The term "Amendment  Effective Date" shall
                                                -------------------------
mean the date of this  Agreement,  as set  forth in the  introductory  paragraph
hereof.

           ANNUAL NET SALES.  The  term  "Annual Net  Sales"  shall  mean,  with
                                          -----------------
respect to a Licensed  Product,  the Net Sales of such Licensed Product during a
Contract Year.

           ANTIBODY  PRODUCT.  The  term  "Antibody   Product"  shall  mean  any
                                           ------------------
Licensed Product for use in the Field which includes a Field Antibody.

           COMBINATION PRODUCT.  The term "Combination Product" means a Licensed
                                           -------------------
Product that  contains  more than one active  ingredient  and where at least one
active ingredient that would, in the absence of a license,  infringe one or more
claims of a Licensed  CYTOGEN Patent (such active  ingredient(s),  the "Licensed
                                                                        --------
Ingredient(s)"),  and where the other active  ingredient(s) would not, in and of
-------------
itself (or themselves), in the absence of a license, infringe one or more claims
of a Licensed CYTOGEN Patent.

           COMMERCIAL  SALE.  The  term  "Commercial   Sale"   shall  mean   the
                                          -----------------
commercial  sale,  by the LLC or its  Sublicensees,  of a Licensed  Product to a
Third Party.  The sale of a Licensed  Product  distributed  or used for clinical
trials or experimental purposes only shall not be considered a Commercial Sale.

           CONTRACT PERIOD.  The term  "Contract  Period"  shall mean the period
                                        ----------------
beginning on the Effective  Date and ending on the date on which this  Agreement
shall  expire or  terminate  in  accordance  with the  provisions  of Section 11
hereof.

           CONTRACT  QUARTER.  The  term  "Contract  Quarter"  shall  mean  each
                                           -----------------
calendar  quarter ending on March 31st,  June 30th,  September 30th and December
31st.


                                       2
<PAGE>

           CONTRACT YEAR.  The term "Contract  Year" shall  mean  each  calendar
                                     --------------
year ending on December 31, or applicable  subpart  thereof in the first or last
Contract Year.

           CYTOGEN. The  term "CYTOGEN" shall have the  meaning set forth in the
                               -------
recitals of this Agreement.

           CYTOGEN   TECHNICAL   INFORMATION.  The  term   "CYTOGEN    Technical
                                                            --------------------
Information"  shall mean Technical  Information  to the extent,  but only to the
-----------
extent,  used or useful in the Field in which  CYTOGEN had, as of the  Effective
Date, a licensable right under the SKICR Agreement,  and for the period from the
Effective Date until the Amendment Effective Date, only to the extent previously
conveyed under Section 3.3 of the Original Agreement.

           EFFECTIVE DATE.  The term "Effective Date" shall mean June 15,  1999,
                                      --------------
the date of the Original Agreement, as set forth on the first page thereof.

           FDA. The term "FDA" shall mean the U.S. Food and Drug Administration.
                          ---

           FIELD.  The  term  "Field"  shall  mean: (a)  any  and  all  means of
                               -----
developing,  making,  having  made,  distributing,  using,  offering  for  sale,
selling,  having sold,  importing or exporting  any Field  Immunogen  and/or any
vaccine  incorporating  any Field  Immunogen  as a  therapeutic,  but  excluding
vaccines for prostate cancer that are antigen  presenting  cells isolated from a
patient's blood, bone marrow or spleen and pulsed ex vivo with a Field Immunogen
for  return to the  patient;  and (b) any and all means of  developing,  making,
having  made,  distributing,  using,  offering for sale,  selling,  having sold,
importing or exporting any Field Antibody as a therapeutic.

           FIELD  ANTIBODY.  The term "Field  Antibody"  shall mean any  peptide
                                       ---------------
that includes a complementarity  determining  region of an antibody  recognizing
one  or  more  Field  Immunogens,  including,  without  limitation,  antibodies,
antibody fragments, antibody derivatives such as humanized antibodies and single
chain  antibodies,  and conjugates of any of the  foregoing,  but excluding MoAb
7E11.

           FIELD IMMUNOGEN.  The term "Field Immunogen" shall mean any immunogen
                                       ---------------
that derives its immunogenicity  wholly or in significant part from PSMA or PSMP
or mimetopes thereof, or any combination of such immunogens.

           FIRST COMMERCIAL SALE.  The term "First  Commercial Sale"  shall mean
                                             ----------------------
with  respect to any  Licensed  Product  and with  respect to any country in the
Territory,  the first  Commercial  Sale of such Product to a Third Party in such
country after such Licensed  Product has been granted  Regulatory  Approval by a
Regulatory Authority having jurisdiction for such country.

           LICENSED CYTOGEN PATENTS.  The term "Licensed CYTOGEN  Patents" shall
                                                -------------------------
mean the Patent  rights  listed on Annex A attached  hereto,  together  with any
other  Patent  within  the  Field  in which  CYTOGEN  had,  as of the  Amendment
Effective Date, a licensable right under the SKICR Agreement.

           LICENSED INGREDIENT(S).  The term "Licensed  Ingredient"  shall  have
                                              --------------------
the meaning set forth in the definition of "Combination Product".


                                       3
<PAGE>


           LICENSED PRODUCT. The term "Licensed Product" shall mean any product,
                                       ----------------
apparatus, method or service, the manufacture,  use, sale, provision or practice
of which  would,  in the absence of a license,  infringe one or more claims of a
Licensed CYTOGEN Patent.

           LLC.  The term "LLC" shall have the meaning set forth in the recitals
                           ---
 of this Agreement.

           LLC AGREEMENT.  The  term  "LLC Agreement"  shall  mean  the  Limited
                                       -------------
Liability Company Agreement,  dated as of June 15, 1999, by and among Progenics,
CYTOGEN and the LLC, and any amendments thereto.

           MANUFACTURING RIGHTS.  The term "Manufacturing Rights" shall have the
                                            --------------------
meaning set forth in Section 2.2(n) hereof.

           MOAB 7E11.  The term "MoAb 7E11" shall mean that certain  antibody to
                                 ---------
PSMA known as MoAb  7E11-C5,  which such  antibody  is claimed in United  States
Patent No.  5,162,504,  granted  November  10, 1992,  and  entitled  "Monoclonal
Antibodies to a New Antigenic Marker in Epithelial  Prostatic Cells and Serum of
Prostate Cancer  Patients." The term "MoAb 7E11" includes all subclones  claimed
in such Patent.

           NDA.  The  term  "NDA"  shall  mean  an  application  submitted  to a
                             ---
Regulatory  Authority for marketing  approval of a product,  including (a) a New
Drug Application,  Product License  Application or Biologics License Application
filed with FDA or any  successor  applications  or  procedures,  (b) any foreign
equivalent  thereof,  and (c) all  supplements  and amendments that may be filed
with respect to the foregoing.

           NET SALES.  The  term  "Net Sales"  shall  mean,  with  respect  to a
                                   ---------
Licensed Product, the gross amount invoiced by or on behalf of the LLC or of its
Sublicensees,  for  Licensed  Products  sold to  Third  Parties  in  BONA  FIDE,
arm's-length  transactions,  less the following  (collectively,  the  "Permitted
                                                                       ---------
Deductions"):   (i)  trade,  cash,  promotional  and  quantity  discounts,   and
----------
wholesaler  fees;  (ii) taxes on sales  (such as  excise,  sales or use taxes or
value added taxes) to the extent  imposed upon and paid directly with respect to
the sales price (and excluding national,  sales or local taxes based on income);
(iii) freight, insurance,  packing costs and other transportation charges to the
extent  included  in the  invoice  price to the buyer;  (iv)  amounts  repaid or
credits taken by reason of damaged goods,  rejections,  defects, expired dating,
recalls,  returns or because  of  retroactive  price  changes;  (v) charge  back
payments  and  rebates  granted to (a)  managed  healthcare  organizations,  (b)
federal, state and/or provincial and/or local governments or other agencies, (c)
purchasers  and  reimbursers,   or  (d)  trade  customers,   including   without
limitation,  wholesalers and chain and pharmacy  buying groups,  all only to the
extent  permitted by applicable law and  regulations;  (vi)  documented  customs
duties  actually paid by the Selling  Person;  and (vii) any other  reduction or
specifically  identifiable  amounts  included in the  Licensed  Product's  gross
invoice that are creditable for reasons substantially equivalent to those listed
above.  Sales between or among the LLC or its Sublicensees  shall be disregarded
for purposes of calculating Net Sales.

               The following provisions apply to sales of Combination  Products.
          If a Licensed Product is sold as a Combination Product (a "Combination
                                                                     -----------
          Sale"),  the Net Sales for such Licensed  Product shall be the
          ----


                                       4
<PAGE>


          portion of the Net Sales amount  attributable to the Combination  Sale
          allocable to the Licensed Ingredient determined as follows:

               (1)  Except  as  provided  below,  the  Net  Sales  amount  for a
          Combination  Sale  shall  equal  the  gross  amount  invoiced  for the
          Combination  Sale,  reduced  by the  Permitted  Deductions  (the  "Net
                                                                             ---
          Combination Sale Amount"), multiplied by the fraction A/(A+B), where:
          -----------------------

          A is the invoice  price,  in the country where such  Combination  Sale
          occurs, of the Licensed Ingredient(s),  if sold as a separate Licensed
          Product  consisting  solely  of the  Licensed  Ingredient(s)  in  such
          country by the Selling  Person;  and B is the aggregate of the invoice
          price or prices,  in such  country,  of such one or more other  active
          ingredients  included in the Combination Product if sold separately in
          such country by the Selling Person.

               (2)  Where  the   calculation  of  Net  Sales  resulting  from  a
          Combination  Sale in a country  cannot be  determined by the foregoing
          method,  the calculation of Net Sales for such  Combination Sale shall
          be  that  portion  of  the  Net  Combination  Sale  Amount  reasonably
          determined  in good faith by the  Parties as properly  reflecting  the
          value  of the  Licensed  Ingredient(s)  included  in  the  Combination
          Product.

           NON-LICENSED PRODUCTS.  The term  "Non-Licensed Products" shall  have
                                              ---------------------
the meaning set forth in Section 5.4.

           NWC.  The term "NWC" shall have the meaning set forth in the recitals
                           ---
of this Agreement.

           NWC Agreement.  The term  "NWC Agreement" shall  have the meaning set
                                      -------------
forth in the recitals of this Agreement.

           OPTION STAGE.  The term  "Option Stage"  shall have  the meaning  set
                                     ------------
forth in Section 5.3.

           ORIGINAL  AGREEMENT.  The term "Original  Agreement"  shall  have the
                                           -------------------
meaning set forth in the recitals of this Agreement.

           OTHER PRODUCT.  The term  "Other  Product" shall  mean  any  Licensed
                                      --------------
Product  for use in the  Field  which is not an  Antibody  Product  or a Vaccine
Product.

           PATENT.  The  term "Patent"  shall mean  (i) unexpired letters patent
                               ------
(including  inventor's  certificates) which have not lapsed or been held invalid
or unenforceable  by a court or  administrative  body of competent  jurisdiction
from  which no appeal can be taken or has been taken  within the  required  time
period,   including,   without   limitation,   any   substitution,    extension,
registration,  confirmation, reissue, reexamination,  renewal or any like filing
thereof and (ii) pending  applications for letters patent that have not been the
subject of a rejection notice from which an appeal cannot be taken or in respect
of which the applicable period of appeal has expired,


                                       5
<PAGE>


including,     without    limitation,    any    continuation,     division    or
continuation-in-part thereof and any provisional applications.

           PERMITTED DEDUCTIONS.  The term "Permitted Deductions" shall have the
                                            --------------------
meaning set forth in the definition of Net Sales.

           PERSON.  The  term "Person"  shall mean  any corporation,  limited or
                               ------
general   partnership,   limited  liability  company,   joint  venture,   trust,
unincorporated association,  governmental body, authority, bureau or agency, any
other entity or body, or an individual.

           PHASE I STUDY.  The term  "Phase I  Study"  shall  mean a  study of a
                                      --------------
Licensed  Product  in human  volunteers  or  patients  the  purpose  of which is
preliminary  determination of the safety and tolerability of a dosing regime and
for which there are no primary  endpoints (as recognized by FDA) in the protocol
relating to efficacy.

           PHASE II STUDY.  The term  "Phase  II  Study"  shall  mean (a) a dose
                                       ----------------
exploration,  dose response,  duration of effect, kinetics, dynamic relationship
or  preliminary  efficacy and safety  study of a Licensed  Product in the target
patient population,  or (b) a controlled dose ranging clinical trial to evaluate
further  the  efficacy  and safety of a Licensed  Product in the target  patient
population and to define the optimal dosing regimen.

           Phase III Study.  The term "Phase III Study" shall mean a  controlled
                                       ---------------
pivotal clinical study of a Licensed  Product that is prospectively  designed to
demonstrate  statistically  whether such Licensed  Product is effective and safe
for use in a particular  indication in a manner  sufficient to obtain Regulatory
Approval to market such product.

           PROGENICS.  The term "Progenics"  shall have the meaning set forth in
                                 ---------
the recitals of this Agreement.

           PROSTAGEN.  The term "Prostagen"  shall have the meaning set forth in
                                 ---------
the recitals of this Agreement.

           PROSTAGEN  AGREEMENT.  The term "Prostagen  Agreement" shall have the
                                            --------------------
meaning set forth in the recitals of this Agreement.

           PSMA.  The term  "PSMA" shall mean prostate specific membrane antigen
                             ----
as described in CANCER RESEARCH,  53:227-230 (1993) and as described in the U.S.
Patent   Application   Serial  Nos.   08/973,337   and   08/394,152,   including
continuations  and  continuations-in-part,  splice variations  thereof,  species
variations thereof,  allelic variations thereof,  and nucleic acids encoding the
same.

           PSMP. The term "PSMP" shall mean prostate specific membrane peptides,
                           ----
which  include any peptide  sequence  appearing  in a PSMA protein and unique to
PSMA proteins, and nucleic acids encoding the same.

           REGULATORY APPROVAL.  The term "Regulatory Approval" shall mean, with
                                           -------------------
respect to a  Licensed  Product in a country,  the  approval  of the  applicable
Regulatory  Authority  necessary  for the  marketing  and sale of such  Licensed
Product in such country.


                                       6
<PAGE>

           REGULATORY AUTHORITY.  The term  "Regulatory  Authority"  shall  mean
                                             ---------------------
the applicable  governmental authority (which, in the United States, is the FDA)
that is  responsible  for approval for  manufacturing,  marketing or importing a
therapeutic agent in a particular country for human use.

           [**].

           ROYALTY BUYDOWN.  The term "Royalty Buydown" shall have  the  meaning
                                       ---------------
set forth in Section 5.3.

           ROYALTY BUYDOWN OPTION.  The  term "Royalty   Buydown  Option"  shall
                                               -------------------------
have the meaning set forth in Section 5.3.

           ROYALTY TERM.  The term "Royalty  Term" shall  mean with  respect  to
                                    -------------

any particular  Licensed Product in any particular  country,  the period of time
commencing on the First Commercial Sale of such Licensed Product in such country
and  extending  until the later of: (a) the  expiration of the last to expire of
any Valid Claim  included in any Licensed  CYTOGEN  Patent in such country which
would be  infringed by an  unlicensed  Third  Party's  manufacture,  use,  sale,
importation,  development or  commercialization  of the Licensed  Product or (b)
[**] of the First Commercial Sale of the Licensed Product in such country.

           SELLING PERSON.  The term "Selling Person"  shall mean  any or all of
                                      --------------
the  LLC or  its  Sublicensees,  as  appropriate,  selling  a  Licensed  Product
(including a Licensed  Product  which is part of a  Combination  Product) or the
active ingredients and/or components thereof.

           SERVICES AGREEMENT.  The  term "Services  Agreement"  shall have  the
                                           -------------------
meaning set forth in the recitals of this Agreement.

           SKICR.  The term "SKICR" shall mean the Sloan-Kettering Institute for
                             -----
Cancer Research, a New York membership corporation having its principal place of
business at 1275 York Avenue, New York, New York 10021.

           SKICR AGREEMENT. The term "SKICR Agreement" shall mean the Option and
                                      ---------------
License Agreement,  effective July 1, 1993, by and between SKICR and CYTOGEN, as
amended by amendment no. 1 thereto effective as of November 22, 1993.

           SKICR  LICENSE.  The term  "SKICR License"  shall  mean  the  license
                                       -------------
granted to CYTOGEN pursuant to the SKICR Agreement.

           SUBLICENSEE.  The term "Sublicensee" shall mean a Person to which the
                                   -----------
LLC grants a sublicense under Section 3.2.

           TECHNICAL INFORMATION.  The term "Technical Information"  shall  mean
                                             ---------------------
unpublished  research  and  development   information,   unpatented  inventions,
formulae, processes, know-how, trade secrets and technical data.

           TERRITORY.  The term "Territory" shall mean the entire world.
                                 ---------


                                       7
<PAGE>


           THIRD PARTY.  The term "Third Party" shall mean any Person other than
                                   -----------
Progenics,  CYTOGEN,  the LLC and their  respective  Affiliates  and, except for
CYTOGEN, their respective Sublicensees.

           THIRD PARTY  LICENSE.  The term "Third Party  License"  shall mean an
                                            --------------------
agreement  between (i) the LLC or one of its Affiliates or Sublicensees and (ii)
a Third Party that grants  intellectual  property  rights that are  necessary or
advisable and that would, in the  commercially  reasonable  judgment of the LLC,
but for such license, be infringed by the manufacture,  use, sale,  importation,
development or  commercialization  of Licensed  Product by the LLC or one of its
Sublicensees.

           VACCINE PRODUCT.  The term "Vaccine  Product" shall mean any Licensed
                                       ----------------
Product  for use in the Field  which  includes a Field  Immunogen  and is not an
Antibody Product.

           VALID  CLAIM.  The term "Valid  Claim"  shall mean a claim (a) of any
                                    ------------
issued,  unexpired  Patent that has not been  revoked or held  unenforceable  or
invalid  by  a  decision  of  a  court  or  governmental   agency  of  competent
jurisdiction  from  which no appeal  can be taken,  or with  respect to which an
appeal is not taken  within the time  allowed for appeal,  and that has not been
disclaimed  or  admitted  to  be  invalid  or  unenforceable   through  reissue,
disclaimer  or  otherwise,  or (b) of any Patent  Application  that has not been
cancelled,  withdrawn or abandoned,  or has not been pending for more than seven
(7) years.

     2.    REPRESENTATIONS AND WARRANTIES.

     2.1   BY THE LLC.
           ----------

     The LLC  represents  and  warrants to CYTOGEN,  as of the date  hereof,  as
follows:

           (a) DUE  ORGANIZATION.  The  LLC  is  a  limited  liability   company
               -----------------
organized and validly existing under the laws of the State of Delaware.

           (b) POWER TO ACT. The LLC has all necessary corporate power under the
               ------------
laws of the State of Delaware to enter into and  perform its  obligations  under
this  Agreement and has taken all necessary  corporate  action under the laws of
the State of Delaware and its  certificate of formation and operating  agreement
to authorize the execution of, and  performance of its obligations  under,  this
Agreement.

           (c) NO DEFAULT.  The LLC is not in default under, or in conflict with
               ----------
respect to, its  certificate of formation or operating  agreement or any term or
provision of any  agreement,  mortgage or indenture to which it is a party or by
which  any of its  properties  are  bound or any  statute,  rule,  order,  writ,
injunction,  decree or regulation applicable to it or any of its properties that
will preclude the  performance  of its  obligations  under this Agreement in any
material respect.

           (d) NO MATERIAL CONTRACTS.  The LLC is not subject to any contract or
               ---------------------
agreement that will preclude or otherwise  conflict with the  performance of its
obligations under this Agreement in any material respect.


                                      8
<PAGE>


           (e)  NO CONFLICTS.   Neither  the  execution  nor  delivery  of  this
                ------------
Agreement,  the  consummation of the  transactions  herein  contemplated nor the
fulfillment  of or  compliance  with the terms and  provisions  hereof  will (i)
require the  consent,  approval  or  authorization  of, or notice,  declaration,
filing or  registration  with,  any  governmental  or regulatory  authority,  or
violate  any  provisions  of law,  administrative  regulation  or  court  decree
applicable  to the LLC or (ii) conflict  with,  result in a breach of any of the
terms, conditions or provisions of or constitute a default under the certificate
of formation or operating agreement of the LLC or of any agreement or instrument
to which it is a party or by which any of its property is bound.

           (f) EXECUTION AND DELIVERY; ENFORCEABILITY.  This  Agreement has been
               --------------------------------------
duly  executed  and  delivered  and  constitutes  the legal,  valid and  binding
obligation  of the LLC,  enforceable  against  it in  accordance  with the terms
hereof,  subject,  as to  enforcement,  to  bankruptcy,  fraudulent  conveyance,
insolvency,  reorganization,  moratorium and other laws relating to or affecting
creditors' rights generally and by general equitable principles.

     2.2   BY CYTOGEN.
           ----------

           CYTOGEN represents and warrants to the LLC, as of the date hereof, as
follows:

           (a) DUE ORGANIZATION.  CYTOGEN is a  corporation  duly  organized and
               ----------------
validly existing under the laws of the State of Delaware.

           (b) POWER TO ACT. CYTOGEN has all necessary corporate power under the
               ------------
laws of the State of Delaware to enter into and  perform its  obligations  under
this  Agreement and has taken all necessary  corporate  action under the laws of
the State of  Delaware  and its  certificate  of  incorporation  and  by-laws to
authorize the execution  of, and  performance  of its  obligations  under,  this
Agreement.  CYTOGEN has the full right,  power and authority to grant all of the
right, title and interest in the licenses granted,  or contingent  licenses that
may be granted, by CYTOGEN under Section 3 hereof.

           (c) NO DEFAULT.  CYTOGEN is not in default under, or in conflict with
               ----------
respect to, its certificate of incorporation or by-laws or any term or provision
of any  agreement,  mortgage or indenture to which it is a party or by which any
of its  properties  are bound or any statute,  rule,  order,  writ,  injunction,
decree  or  regulation  applicable  to it or  any of its  properties  that  will
preclude the performance of its obligations under this Agreement in any material
respect.

           (d) NO MATERIAL CONTRACTS.  CYTOGEN is not subject to any contract or
               ---------------------
agreement that will preclude or otherwise  conflict with the  performance of its
obligations under this Agreement in any material respect.

          (e)  NO  CONFLICTS.   Neither  the  execution  nor  delivery  of  this
               -------------
Agreement,  the  consummation of the  transactions  herein  contemplated nor the
fulfillment  of or  compliance  with the terms and  provisions  hereof  will (i)
require the  consent,  approval  or  authorization  of, or notice,  declaration,
filing or  registration  with,  any  governmental  or regulatory  authority,  or
violate  any  provisions  of law,  administrative  regulation  or  court  decree
applicable  to CYTOGEN or (ii) conflict  with,  result in a breach of any of the
terms, conditions or provisions of or constitute a


                                       9
<PAGE>


default under the certificate of  incorporation  or by-laws of CYTOGEN or of any
agreement or  instrument  to which it is a party or by which any of its property
is bound.

           (f) EXECUTION AND DELIVERY;  ENFORCEABILITY.  This Agreement has been
               ---------------------------------------
duly  executed  and  delivered  and  constitutes  the legal,  valid and  binding
obligation  of  CYTOGEN,  enforceable  against it in  accordance  with the terms
hereof,  subject,  as to  enforcement,  to  bankruptcy,  fraudulent  conveyance,
insolvency,  reorganization,  moratorium and other laws relating to or affecting
creditors' rights generally and by general equitable principles.

           (g) SKICR AGREEMENT. (i) Attached as Exhibit 1 is a true and complete
               ---------------
copy of the SKICR  Agreement  including all  amendments  thereto.  Copies of all
material   correspondence  between  CYTOGEN  and  SKICR  through  the  Amendment
Effective  Date have been  delivered  by  CYTOGEN to the LLC and  Progenics.  No
provision of the SKICR Agreement has been amended, modified or waived, except as
set forth in Exhibit 1. All of the rights  granted under the SKICR  Agreement to
CYTOGEN are valid and  enforceable,  and neither this Agreement nor the Purchase
Agreement  contravene  any  provision  of the SKICR  Agreement or give rise to a
termination  right  thereunder.  (ii)  Except  as set  forth  in  Exhibit  1, to
CYTOGEN's  knowledge,  the  representations  and warranties made by SKICR in the
SKICR Agreement were true in all material respects when made; there has occurred
no act or failure to act that would  render such  representations  untrue in any
material  respect  if made on and as of the date  hereof;  and  there  exists no
breach or anticipatory breach by SKICR of any of its material  obligations under
the SKICR Agreement.  (iii) The SKICR Agreement is in full force and effect, and
CYTOGEN has complied in all material  respects with its obligations  thereunder.
There does not exist any default by CYTOGEN  under such  agreement  that,  after
notice  or the  lapse of time or both,  would  constitute  a  material  event of
default or give rise to a right of  termination  thereunder.  (iv)  CYTOGEN  has
neither  given nor  received  any  notice of  termination  or breach  under such
agreements.  (v) In the event of any  misrepresentation or breach of warranty by
SKICR under the SKICR  Agreement,  CYTOGEN will  cooperate  with all  reasonable
requests of the LLC or its  Affiliates  regarding  the assertion of any claim or
cause of action against SKICR for such  misrepresentation or breach of warranty;
provided,  that the LLC shall bear any and all costs,  expenses,  liabilities or
--------
obligations of CYTOGEN in connection therewith or arising therefrom.

           (h) NO LITIGATION, CLAIMS OR CONFLICTS. (i) There is no action, suit,
               ----------------------------------
claim or  proceeding  pending or  threatened  against  CYTOGEN or, to  CYTOGEN's
knowledge,  SKICR with respect to any of the Licensed CYTOGEN Patents or CYTOGEN
Technical  Information,  either  at  law  or in  equity,  before  any  court  or
administrative agency or before any governmental department,  commission, board,
bureau, agency or instrumentality, whether United States or foreign, relating to
validity,  infringement,  ownership or  otherwise,  and neither  CYTOGEN nor, to
CYTOGEN's  knowledge,  SKICR has  received  any notice that any person may bring
such a claim, and CYTOGEN has no belief that any basis or grounds exists for any
such  actions,  suits or claims.  (ii) Except as disclosed to the LLC by counsel
for the LLC, to CYTOGEN's knowledge there are no conflicts with or violations or
infringements  of any rights or asserted rights of any other person with respect
to the Licensed  CYTOGEN  Patents or the CYTOGEN  Technical  Information.  (iii)
There are no  proceedings  or claims  pending in which  CYTOGEN or, to CYTOGEN's
knowledge,  SKICR  alleges  that any person is  infringing  upon,  or  otherwise
violating, any of the Licensed CYTOGEN Patents or CYTOGEN Technical Information,


                                       10
<PAGE>


nor are any proceedings threatened by CYTOGEN or, to CYTOGEN's knowledge,  SKICR
alleging any such violation or infringement.

           (i)  SUBSISTING RIGHTS. The Licensed  CYTOGEN Patents in existence on
                -----------------
the date hereof are in full force and effect,  have been  maintained to date and
are not invalid or  unenforceable,  in whole or in part. No act has been done or
omitted to be done which had or could have the effect of impairing or dedicating
to the public,  or  entitling  any U.S. or foreign  government  authority or any
other  person to  cancel,  forfeit,  modify  or  consider  abandoned  any of the
Licensed  CYTOGEN  Patents,  or give any person any rights with respect thereto.
All of  CYTOGEN's  rights under the SKICR  Agreement,  and  CYTOGEN's  ownership
rights in the  Patents  listed in  paragraph  2 of Annex A  hereof,  are  valid,
enforceable and free of defects.

           (j)  CONFIDENTIALITY; EFFECTIVE WAIVERS.  (i) Neither CYTOGEN nor, to
                ----------------------------------
CYTOGEN's knowledge, SKICR has divulged,  furnished to or made accessible to any
person any trade  secrets  included in the Licensed  CYTOGEN  Patents or CYTOGEN
Technical  Information  without  prior thereto  having  obtained an agreement of
confidentiality  from such person.  CYTOGEN and, to CYTOGEN's  knowledge,  SKICR
have  obtained  from all  individuals  who  participated  in any  respect in the
invention or authorship  of any Licensed  CYTOGEN  Patents or CYTOGEN  Technical
Information (as employees,  consultants or otherwise)  effective  waivers of any
and all ownership  rights of such  individuals in such rights and assignments to
CYTOGEN or SKICR, as applicable, all rights with respect thereto.

           (k) PATENT PROSECUTION  DISCLOSURE.  CYTOGEN has disclosed to the LLC
               ------------------------------
all of the  prosecution  files of all of the  patents  and  patent  applications
licensed to the LLC by CYTOGEN hereunder.

           (l) PATENTS IN THE FIELD. To CYTOGEN's knowledge, on the date hereof,
               --------------------
CYTOGEN  does not have a  licensable  right to any Patent  used or useful in the
Field except as disclosed on Annex A hereto.

           (m)  NO  PRIOR  TRANSFER.  CYTOGEN  has not  sublicensed,   assigned,
                -------------------
transferred,  conveyed or otherwise  encumbered its right, title and interest in
any of the Licensed CYTOGEN Patents or CYTOGEN Technical  Information other than
pursuant to the Original Agreement.

           (n) NWC. The NWC  Agreement has been terminated  and no rights in the
               ---
Field remain  outstanding  under the NWC  Agreement.  All rights in the Field to
Patents  and  Technical   Information  granted  thereunder  (the  "Manufacturing
                                                                   -------------
Rights") have been reacquired by CYTOGEN. There are no subsisting liabilities to
------
NWC stemming from or relating to termination of the NWC Agreement.

           (o)  MANUFACTURING RIGHTS.  Without  limiting the  generality  of the
                --------------------
license  granted to the LLC under Section 3.1, the Licensed  CYTOGEN Patents and
CYTOGEN Technical  Information include Manufacturing Rights to the extent of the
Field. CYTOGEN hereby retains all Manufacturing Rights outside of the Field.

           (p)  EXCLUSIVE OWNER, ETC. CYTOGEN is the sole and exclusive licensee
                --------------------
of the rights licensed to CYTOGEN under the SKICR Agreement of the rights to the
Patents listed


                                       11
<PAGE>


in Annex A hereof,  which sets forth a complete  and  accurate  list of Licensed
CYTOGEN  Patents as of date hereof,  all of which Patents listed in Annex A are,
to  CYTOGEN's  knowledge,  owned  free  and  clear  of any  liens,  charges  and
encumbrances,  and no other person, corporation or other private or governmental
entity  or  subdivision  thereof  has or shall  have  any  claims  of  ownership
whatsoever  with respect to such rights.  There are no judgments or  settlements
against or owed by CYTOGEN relating to such rights.

           (q) ORIGINAL AGREEMENT. CYTOGEN has complied in all material respects
               ------------------
with Section 4.6 of the Original Agreement.

     2.3   BY PROGENICS.  Progenics  represents and  warrants to  CYTOGEN, as of
           ------------
the date hereof, as follows:

           (a) DUE ORGANIZATION.  Progenics is a corporation  duly organized and
               ----------------
validly existing under the laws of the State of Delaware.

           (b) POWER TO ACT.  Progenics has all necessary corporate  power under
               ------------
the laws of the State of  Delaware  to enter into and  perform  its  obligations
under this Agreement and has taken all necessary corporate action under the laws
of the State of Delaware and its  certificate  of  incorporation  and by-laws to
authorize the execution  of, and  performance  of its  obligations  under,  this
Agreement. Progenics has the full right, power and authority to grant all of the
right, title and interest in the licenses granted,  or contingent  licenses that
may be granted, by Progenics under this Agreement.

           (c) NO DEFAULT.  Progenics is  not in default  under, or in  conflict
               ----------
with  respect to, its  certificate  of  incorporation  or by-laws or any term or
provision of any  agreement,  mortgage or indenture to which it is a party or by
which  any of its  properties  are  bound or any  statute,  rule,  order,  writ,
injunction,  decree or regulation applicable to it or any of its properties that
will preclude the  performance  of its  obligations  under this Agreement in any
material respect.

           (d) NO MATERIAL CONTRACTS.  Progenics is not subject  to any contract
               ---------------------
or agreement  that will preclude or otherwise  conflict with the  performance of
its obligations under this Agreement in any material respect.

           (e)  NO  CONFLICTS.  Neither  the  execution  nor  delivery  of  this
                -------------
Agreement,  the  consummation of the  transactions  herein  contemplated nor the
fulfillment  of or  compliance  with the terms and  provisions  hereof  will (i)
require the  consent,  approval  or  authorization  of, or notice,  declaration,
filing or  registration  with,  any  governmental  or regulatory  authority,  or
violate  any  provisions  of law,  administrative  regulation  or  court  decree
applicable to Progenics or (ii) conflict with,  result in a breach of any of the
terms, conditions or provisions of or constitute a default under the certificate
of  incorporation  or by-laws of Progenics or of any  agreement or instrument to
which it is a party or by which any of its property is bound.

           (f) EXECUTION AND DELIVERY; ENFORCEABILITY.  This  Agreement has been
               --------------------------------------
duly  executed  and  delivered  and  constitutes  the legal,  valid and  binding
obligation of  Progenics,  enforceable  against it in accordance  with the terms
hereof,  subject,  as to  enforcement,  to  bankruptcy,  fraudulent  conveyance,
insolvency,  reorganization,  moratorium and other laws relating to or affecting
creditors' rights generally and by general equitable principles.


                                       12
<PAGE>


     2.4   BY ALL PARTIES.  Each Party  represents and  warrants to  each of the
           --------------
others, as of the date hereof, that it has not breached or violated,  and is not
in breach or violation of, the Original Agreement.

     3.    LICENSES.

     3.1   GRANT  BY  CYTOGEN.  Subject  to  the  terms  and  conditions  herein
           ------------------
contained,  CYTOGEN  hereby  grants to the LLC,  to the extent  (but only to the
extent) of the Field,  the  exclusive  (even as to  CYTOGEN)  right and  license
throughout  the  Territory  under the Licensed  CYTOGEN  Patents and the CYTOGEN
Technical Information to develop,  make, have made,  distribute,  use, offer for
sale,  sell,  have  sold,  import  or  export  Licensed  Products.  The  Parties
acknowledge  and agree that the LLC shall not be  restricted  in its use for any
purpose of Technical  Information  developed or otherwise acquired by it, except
to the extent such Technical  Information is CYTOGEN Technical  Information,  in
which case it will be  treated  in  accordance  with the  immediately  preceding
sentence.

     3.2   SUBLICENSES.
           -----------

           The  LLC  shall have  the right to grant  sublicenses  of the  rights
granted  hereunder,  provided  that: (i) each  Sublicensee  shall have agreed in
                     --------
writing to keep books and  records  and permit  CYTOGEN to review such books and
records  pursuant to the  relevant  provisions,  and to comply with all terms of
this Agreement expressly applicable to a Sublicensee of the LLC; and (ii) within
15 days of granting any such  sublicense  the LLC shall give  written  notice of
such grant to CYTOGEN and provide  CYTOGEN  with a copy of such  sublicense.  No
consent or approval of CYTOGEN shall be required in connection with the granting
of such  sublicenses.  Upon  reasonable  request of any  Sublicensee of the LLC,
CYTOGEN shall  cooperate  with such  Sublicensee  to execute,  acknowledge,  and
deliver all documentation,  further assurances and other instruments solely with
respect to the existence and good standing of this Agreement,  including without
limitation copies of the SKICR Agreement,  as amended through the relevant date,
and  correspondence  relating thereto;  provided,  that, subject to Section 3.4,
                                        --------
CYTOGEN  will not (i) be or  become  obligated  to pay any fees or  unreimbursed
expenses; (ii) incur any additional  obligations;  or (iii) be required to amend
or deemed to have  amended  this  Agreement  or the SKICR  Agreement,  solely by
reason  thereof.  Without  limiting  the  generality  of  the  foregoing,  it is
understood  and  agreed  that the LLC may grant  sublicenses  to its  Affiliates
("Affiliate  Sublicensees")  of all or any part(s) of its rights  hereunder,  in
  -----------------------
accordance with this Section 3.2; provided,  that it shall be a condition to any
                                  --------
such sublicense to such an Affiliate Sublicensee that such Affiliate Sublicensee
agrees to make available directly to CYTOGEN,  upon the prior written request of
CYTOGEN,  such portion of sums owing by such  Affiliate  Sublicensee  to the LLC
under the  relevant  sublicense  agreement  to which  CYTOGEN is entitled  under
Article 5 hereof.

     3.3   GUARANTEE OF PERFORMANCE OF SUBLICENSEE.
           ---------------------------------------

            The LLC hereby unconditionally guarantees to CYTOGEN the performance
of any of its Sublicensees'  financial obligations  hereunder,  including making
all payments due, and making all reports  required,  under this  Agreement to be
made by reason  of sales of  Licensed  Products  by its  Sublicensees  and their
compliance with all applicable terms of this Agreement.  In any such sublicense,
the Sublicensee  shall agree that in the event of a breach by the Sublicensee in


                                       13
<PAGE>


the  observance  of any  applicable  terms of this  Agreement,  CYTOGEN shall be
entitled to proceed  against such  Sublicensee  or directly  against the LLC, as
CYTOGEN may determine, in its sole discretion, to enforce this Agreement.

     3.4   CURE  OF BREACH BY SUBLICENSEE.  Upon notification  to CYTOGEN by the
           ------------------------------
LLC of the grant by the LLC of any  sublicense  under  this  Agreement,  CYTOGEN
shall become  obligated to notify in writing any such  Sublicensee of any breach
by the LLC  hereunder,  or of any purported  termination  by CYTOGEN,  with such
notice to be sent to such  Sublicensee (at the address  specified by the LLC) at
the same time as notice is sent to the LLC.  In the event that the LLC  breaches
this  Agreement,  which breach  remains  uncured  through the  expiration of any
applicable  cure period,  any  Sublicensee  of the LLC hereunder  shall have the
right,  but not the obligation,  during a period of 45 days after the expiration
of the  aforesaid  cure period,  to cure such breach in its own name,  and, upon
curing such breach,  such Sublicensee shall have the right to be substituted for
the LLC as a direct  sublicensee  under the Licenses to the exclusion of, and on
the same terms as, the LLC to the extent of the  sublicense.  A provision to the
effect of the foregoing shall be included in any sublicense granted hereunder.

     3.5   [**].

     3.6   RESERVATION OF RIGHTS. CYTOGEN reserves the right to practice and use
           ---------------------
the CYTOGEN  Technical  Information  and to develop,  make,  have made,  and use
Licensed Products, in each case, without cost and subject to the confidentiality
provisions  of  this  Agreement,   for  non-commercial   internal  research  and
development purposes.

     3.7   NO OTHER RIGHTS. Except as expressly provided herein, no right, title
           ---------------
or interest is granted by CYTOGEN under the Licensed  CYTOGEN Patents or CYTOGEN
Technical  Information  or  otherwise.  CYTOGEN  expressly  does not grant,  and
nothing  contained  herein  is  intended  to  grant,  or shall be  construed  as
granting, any right, title or interest outside of the Field.

     3.8   COMPETITION NOT PROHIBITED.  No license granted under this Agreement,
           --------------------------
and no other provision contained herein,  shall be deemed to prohibit the LLC or
CYTOGEN or any of their  respective  Affiliates  from  engaging in any  activity
outside of the Field.

     4.    CERTAIN COVENANTS.

     4.1   NO WAIVERS OR GRANT OF FURTHER  RIGHTS. CYTOGEN will not, without the
           --------------------------------------
prior written consent of the LLC, terminate,  amend, modify or grant any waivers
or consents under any the SKICR  Agreement  with respect to the Field,  or grant
any  further  rights  to the  Licensed  CYTOGEN  Patents  or  CYTOGEN  Technical
Information  in the Field  except  to the LLC,  or take any  other  action  with
respect to the Licensed  CYTOGEN  Patents or the CYTOGEN  Technical  Information
that could adversely affect the rights granted to the LLC hereunder.

     4.2   SUMMARY  REPORTS.  For so long  as the  LLC  is  developing  Licensed
           ----------------
Products,  the LLC shall keep CYTOGEN  informed  through written summary reports
about the status of the development of Licensed Products.  Such reports shall be
provided to CYTOGEN on a quarterly basis,  with the first report due on June 30,
2006.  The sole remedy for breach of this Section 4.2, is  compliance by the LLC
with this Section 4.2 upon notice by CYTOGEN.


                                       14
<PAGE>


     4.3   BREACH  OF SKICR  AGREEMENT. In  the event  that CYTOGEN  shall be in
           ---------------------------
breach of or default under any of the material  terms,  conditions or agreements
contained  in the SKICR  Agreement  to be kept,  observed or performed by it, or
receives notice of breach or termination of or default under such agreements, it
shall immediately  notify the LLC thereof.  If CYTOGEN has not cured such breach
or default  within 30 days after the effective date of any notice of termination
issued with respect to such breach or default, the LLC shall have the right, but
not the obligation,  to cure any such breach or default in its own name, and the
LLC shall have the right to be substituted for CYTOGEN as direct licensee in the
Field under either such agreement to the exclusion of, and on the same terms as,
CYTOGEN.  If the LLC elects not to cure such  breach or default or fails to cure
such breach or default within 40 days of the notice,  then Progenics  shall have
the right, but not the obligation, to cure any such breach or default in its own
name, and Progenics shall have the right to be substituted for CYTOGEN as direct
licensee in the Field under either such  agreement to the  exclusion  of, and on
the same terms as, CYTOGEN.  The 30-day and 40-day periods described above shall
be  extended on a  one-for-one  basis as a result of any  extension  to the cure
period set forth in Section IV.D.1 of the SKICR  Agreement  agreed to in writing
by SKICR.

     4.4   NOTICES UNDER THE SKICR AGREEMENT.  CYTOGEN  shall  require  SKICR to
           ---------------------------------
furnish  copies of all notices and other  communications  required or  permitted
under such the SKICR Agreement  (including  without limitation notices of breach
or  termination)  to the  LLC  and,  upon  the  request  of  the  LLC,  to  such
Sublicensee(s) of the LLC or as the LLC shall specify. In addition, CYTOGEN will
furnish  copies  of all  notices  and  communications  to the LLC and,  upon the
request of the LLC, to such Sublicensee(s) of the LLC as the LLC shall specify.

     4.5   COMPLIANCE  WITH TERMS OF THE  SKICR AGREEMENT;  ASSIGNMENT.  CYTOGEN
           -----------------------------------------------------------
shall fulfill each of its obligations  under the SKICR Agreement.  The LLC shall
undertake the efforts  required of CYTOGEN  under Section  VIII.A.1 of the SKICR
Agreement  within the Field.  Without  limiting the generality of the foregoing,
within 30 days of the execution of this Agreement, CYTOGEN shall notify SKICR of
the  execution  of this  Agreement  and  provide  SKICR  with the LLC's name and
address as required by Section III.D.3 of the SKICR Agreement.  CYTOGEN will not
assign any interests  under the SKICR  Agreement  unless the assignee  expressly
agrees to take such interest subject to the interest of the LLC hereunder.

     4.6   TERMINATION  OF SERVICES  AGREEMENT. The Parties hereby terminate, in
           -----------------------------------
its entirety,  the Services  Agreement and each Party  releases each other Party
from any obligations thereunder and from any liabilities relating thereto.

     5.    ROYALTIES  AND  OTHER  PAYMENTS.  In  further  consideration for  the
exclusive  licenses  granted by CYTOGEN to the LLC pursuant to the provisions of
Section 3.1 hereof,  the LLC agrees to make the following payments to CYTOGEN as
follows:

     5.1   MILESTONE  PAYMENTS.  The  LLC  shall  make  the  following  one-time
           -------------------
payments to CYTOGEN upon achievement of the milestone events set forth below:

           (a) Antibody Product Milestones:
               ---------------------------

                  [**]:


                                       15
<PAGE>


--------------------------------------------------------------------------------
Milestone Event For Antibody Products:                         Payment Amount
-------------------------------------                          --------------

--------------------------------------------------------------------------------
     Upon [**] of [**] in the [**]:                                $[**]
--------------------------------------------------------------------------------

                  [**]:

--------------------------------------------------------------------------------
Milestone Events For Antibody Products:                        Payment Amount
--------------------------------------                         --------------

--------------------------------------------------------------------------------
     Upon [**] for the [**] of at least $[**]:                     $[**]
--------------------------------------------------------------------------------
     Upon [**] for [**] of at least $[**]:                         $[**]
--------------------------------------------------------------------------------

           (b) Vaccine Product Milestones:
               --------------------------

                  [**]:

--------------------------------------------------------------------------------
Milestone Events For Vaccine Products:                         Payment Amount
-------------------------------------                          --------------

--------------------------------------------------------------------------------
     Upon [**] of any [**] in the [**]:                            $[**]
--------------------------------------------------------------------------------

                  [**]:

--------------------------------------------------------------------------------
Milestone Events For Vaccine Products:                         Payment Amount
-------------------------------------                          --------------

--------------------------------------------------------------------------------
     Upon [**] for the [**] of at least $[**]:                     $[**]
--------------------------------------------------------------------------------
     Upon [**] for the [**] of at least $[**]:                     $[**]
--------------------------------------------------------------------------------


Each of the Regulatory  Approval  milestone  payments payable under this Section
5.1 shall be payable only [**] in relation to Antibody Products and only [**] in
relation to Vaccine Products,  regardless of [**]. [**] milestones payable under
this  Section 5.1 shall be payable only [**] in respect of [**] and only [**] in
respect of [**].

     5.2   ROYALTIES.
           ---------

           (a) Subject to Section 5.3, commencing with the First Commercial Sale
of an Antibody Product, and thereafter during the relevant Royalty Term, the LLC
shall pay to CYTOGEN,  on an Antibody  Product-by-Antibody  Product basis in the
Territory, royalties in the amount of [**]% of Annual Net Sales of such Antibody
Product.

           (b) Subject to Section 5.3, commencing with the First Commercial Sale
of a Vaccine Product,  and thereafter  during the relevant Royalty Term, the LLC
shall pay to


                                       16
<PAGE>


CYTOGEN the following royalties on a Vaccine Product-by-Vaccine Product basis in
the Territory for Annual Net Sales of such Vaccine Product:

--------------------------------------------------------------------------------
Incremental Annual Net Sales of a Vaccine Product (on a          Royalty Rate
-------------------------------------------------------          ------------
Vaccine-Product-by-Vaccine Product basis) in the
------------------------------------------------
Territory during the applicable Calendar Year:
---------------------------------------------

--------------------------------------------------------------------------------
     For the portion of Annual Net Sales less than $[**]:           [**]%
--------------------------------------------------------------------------------
     For the  portion of Annual  Nets Sale equal to or greater      [**]%
     than  $[**],  but less than $[**]:
--------------------------------------------------------------------------------
     For the portion of Annual Net Sales equal to or greater        [**]%
     than $[**]:
--------------------------------------------------------------------------------


     5.3   ROYALTY BUYDOWN.
           ---------------

           (a) The LLC shall have the option (the  "Royalty  Buydown Option") as
                                                    -----------------------
set forth below,  based on the stage of development  (the "Option Stage") of the
                                                           ------------
first Antibody  Product and first Vaccine Product,  respectively,  to reach such
Option Stage, to pay to CYTOGEN the amount  indicated  below,  to  prospectively
relieve the LLC of the  financial  obligation to pay any royalties on Annual Net
Sales of all  Antibody  Products  and Annual Net Sales of all Vaccine  Products,
respectively (the "Royalty Buydown"):
                   ---------------

--------------------------------------------------------------------------------
Option Stage                                   Antibody      Vaccine
------------                                   --------      -------
                                               Product       Product
                                               -------       -------
--------------------------------------------------------------------------------
  Prior to [**]                                $[**]         $[**]
--------------------------------------------------------------------------------
  Upon and following [**]                      $[**]         $[**]
--------------------------------------------------------------------------------
  Upon and following [**]                      $[**]         $[**]
--------------------------------------------------------------------------------
  Upon and following [**]                      $[**]         $[**]
--------------------------------------------------------------------------------


           (b) The LLC shall  give written  notice of its  intent to  exercise a
Royalty  Buydown  Option for an Antibody  Product or Vaccine  Product to CYTOGEN
during an Option Stage.  Payment to CYTOGEN from the LLC shall be made within 30
days of delivery of such written notice and such payment shall  constitute  full
and final  satisfaction of the LLC's royalty payment  obligations  under Section
5.2 in respect of all Antibody  Products in the case of an Option Stage  payment
for an Antibody Product,  or all Vaccine Products in the case of an Option Stage
payment  for a Vaccine  Product.  The Royalty  Buydown  shall  become  effective
immediately  upon  receipt of notice of the Royalty  Buydown  Option by CYTOGEN.
Notwithstanding the foregoing,  the LLC shall pay to CYTOGEN:  (i) all milestone
payments,  payable under Section 5.1, but only upon achievement of the events as
set forth in, and in  accordance  with,  Section 5.1; and (ii) royalty


                                       17
<PAGE>

payments  which accrued  before the effective  date of the Royalty  Buydown,  in
accordance with Section 5.2.

     5.4   REDUCTION OF ROYALTIES IF THIRD PARTY LICENSE REQUIRED.  If  the  LLC
           ------------------------------------------------------
determines that it cannot reasonably develop or commercialize a Licensed Product
in a particular country in the Territory without obtaining a Third Party License
and the LLC  thereafter  obtains and pays for the Third Party  License,  the LLC
shall be entitled to reduce,  on a [**],  the applicable  royalty  payable under
Section 5.2; provided,  however, that in no event shall this deduction cause the
             --------   -------
amounts payable to CYTOGEN, in respect of such Licensed Product in such country,
to be less than  [**] of the   amount  otherwise  payable  to  CYTOGEN  for such
Contract Quarter in respect of such Licensed Product in such country. Any amount
which would have reduced a royalty payment pursuant to the immediately preceding
sentence,  but was not applied due to the [**] limit  therein, shall be credited
against  royalties  payable  in  subsequent  Contract  Quarters,  subject to the
foregoing percentage restriction, until all such amounts have been credited. The
Third Party License  costs  provided  above shall be discounted  for purposes of
this Section 5.4 if such Third Party  License is  applicable  to products of the
LLC  or  any  Sublicensee  other  than  the  Licensed  Products   ("Non-Licensed
                                                                    ------------
Products") as follows:  such  discount  shall be determined at the time payments
--------
are made under the Third Party License and shall be based on the relation of (i)
the economic value of the rights applicable to the Non-Licensed Products to (ii)
the economic value of the rights applicable to the Licensed Products.

     5.5   PAYMENTS  ASSOCIATED WITH  EXISTING THIRD  PARTY AGREEMENTS.  The LLC
           -----------------------------------------------------------
shall pay earned royalties to CYTOGEN, under the SKICR Agreement, at the minimum
royalty rate(s)  required to be paid and at the times any such payments are due.
In  addition,  the LLC will pay to CYTOGEN  fees equal in amount to the  minimum
amount of any  minimum  royalty  (to the  extent  such  royalty  exceeds  earned
royalties)  or  other  fees  required  to be paid by  CYTOGEN  under  the  SKICR
Agreement at the times any such payments are due. Any fees (but excluding earned
royalties)  payable by the LLC to CYTOGEN  pursuant to this Section 5.5 shall be
discounted  by [**] to  reflect  the  value of  rights  sublicensed  by SKICR to
CYTOGEN but not sublicensed by CYTOGEN to the LLC.

     5.6   OTHER  PRODUCTS.  Other  Products  shall  be  deemed  to  be Antibody
           ---------------
Products (i) for purposes of  determining  royalties  payable  under Section 5.2
with respect to Commercial Sales of Other Products, and (ii) for purposes of the
Royalty Buydown under Section 5.3. For the avoidance of doubt, in the event that
the LLC exercises the Royalty Buydown Option in respect of an Antibody  Product,
such Royalty Buydown shall also relieve the LLC of financial  obligations to pay
any royalties on Annual Net Sales of all Other Products.

     6.    PATENT PROSECUTION AND MAINTENANCE, ETC.

     6.1   PROSECUTION  AND  MAINTENANCE.  To  the  fullest  extent  legally and
           -----------------------------
contractually entitled,  CYTOGEN hereby grants to the LLC the exclusive right to
prepare  new  applications  based  on  CYTOGEN  Technical  Information  licensed
hereunder,  prepare continuing patent applications which contain claims directed
to  subject  matter  in the Field and claim  priority  to the  Licensed  CYTOGEN
Patents,  file,  and prosecute  patent  applications  that are Licensed  CYTOGEN
Patents,  maintain  or extend the term of any issued  patent  that is a Licensed
CYTOGEN Patent,  and defend against any conflicts,  oppositions or interferences
involving Third Party


                                       18
<PAGE>


challenges to the Licensed CYTOGEN Patents. The cost of such activities shall be
borne by the LLC; provided,  however, that if less than all of the rights to any
                  --------   -------
such Patent has been  licensed to the LLC  pursuant  hereto,  the LLC shall bear
only that portion of the cost of such  activities as reflects the  proportionate
economic  value,  as agreed  upon in good  faith by the  Parties,  of the rights
licensed to the LLC.  CYTOGEN shall  cooperate,  at the LLC's expense,  with all
reasonable  requests of the LLC in all such  activities.  If at any time the LLC
determines  not to  prepare,  file or  prosecute  a Patent  licensed  to the LLC
hereunder,  maintain  or  extend  the  term of any  Patent  licensed  to the LLC
hereunder  or  defend  against  any  conflicts,   oppositions  or  interferences
involving  Third Party  challenges to any Patent  licensed to the LLC hereunder,
the LLC shall notify CYTOGEN of any such determination and grant back to CYTOGEN
the  right to  conduct  any such  activity.  If the  right to  prepare,  file or
prosecute any Patent licensed by CYTOGEN to the LLC hereunder, or to maintain or
extend  or  to  defend  against  any  Third  Party  conflicts,   oppositions  or
interferences  involving  any Patent  licensed  to the LLC  hereunder  cannot be
granted to the LLC, CYTOGEN shall use commercially reasonable efforts diligently
to  perform,  or cause  to be  performed,  in  consultation  with the LLC,  such
activities.  In  addition,  to the  fullest  extent  legally  and  contractually
entitled,  CYTOGEN  grants  to the LLC the right to review  and  comment  on the
prosecution  and  maintenance  of patents  and patent  applications  which claim
priority  to or  are  otherwise  related  to the  Patents  licensed  to the  LLC
hereunder.  The cost of such  activities  shall  be borne by the LLC;  provided,
                                                                       --------
however,  that if less  than  all of the  rights  to any  such  Patent  has been
-------
licensed to the LLC pursuant hereto, the LLC shall bear only that portion of the
cost of such activities as reflects the proportionate  economic value, as agreed
upon in good faith by the  Parties,  of the rights  licensed to the LLC. The LLC
also grants to CYTOGEN the right to review and  comment on the  prosecution  and
maintenance  of patents and patent  applications  which claim priority to or are
otherwise related to the Patents licensed to the LLC hereunder. The cost of such
activities  shall be borne by CYTOGEN.  Upon issuance of a patent based upon any
pending patent application listed in Annex A, or any continuation in whole or in
part derived therefrom, Annex A shall be revised to reflect the issuance of such
patent.  In the event such an issued  patent  contains  claims  directed only to
subject  matter which falls entirely  outside of the Field,  the patent shall be
removed  from Annex A. For  purposes of clarity,  upon  removal of a patent from
Annex A, the patent  shall be  considered  to fall  outside  the  definition  of
Licensed CYTOGEN Patents.

     6.2   DISCLOSURE  REGARDING PATENT ACTIVITIES.  Each Party which engages in
           ---------------------------------------
patent  activities of the nature  described in section 6.1 hereof shall promptly
provide the other Parties with all correspondence (including any filings sent or
received) and all other information  concerning such activities which comes into
such Party's possession,  and shall periodically update the other Parties on all
relevant information  concerning the actions described in Section 6.1 hereof. In
addition to the foregoing,  each Party required to disclose information pursuant
to this Section 6.2 shall provide to the other Parties a reasonable  opportunity
to review any materials to be submitted or filed with any patent or governmental
authority  or in  connection  with any such  proceeding  and to  comment on such
materials and will discuss and consider such comments in good faith. The Parties
consent to the disclosure of such  correspondence by the LLC, at its discretion,
to any and  all of its  Affiliates  and  any  Sublicensee,  provided  that  such
                                                            --------
Affiliates  and  Sublicensees   shall  receive  such   correspondence   under  a
confidential  disclosure agreement reasonably satisfactory in form and substance
to Progenics or CYTOGEN, as the case may be.


                                       19
<PAGE>


     7.    REPORTS AND ROYALTY PAYMENTS; BOOKS AND RECORDS

     7.1   REPORTS. On or before the last day of each February, May, August, and
           -------

November  commencing  with the first such date  following  the First  Commercial
Sale,  and  thereafter  throughout  the Contract  Period,  the LLC shall furnish
CYTOGEN with a written report,  signed by an authorized  officer or agent of the
LLC, showing all Commercial Sales with respect to which earned royalties are due
to CYTOGEN  hereunder  with  respect in each case to the  immediately  preceding
Contract Quarter.

     7.2   ROYALTY  PAYMENTS.  With each  such quarterly  report, the  LLC shall
           -----------------
remit to CYTOGEN the total amount of earned  royalties  shown thereby to be due.
All payments (and all payments under Section 5) shall be made in lawful funds of
the United States of America.

     7.3   CALCULATION OF ROYALTIES AND OTHER PAYMENTS.  In order to  permit the
           -------------------------------------------
LLC to calculate the amount of royalties and other payments  payable pursuant to
Section 5 hereof,  CYTOGEN shall provide to the LLC true and complete  copies of
the SKICR  Agreement.  CYTOGEN will also furnish the LLC with a written  report,
signed by an  authorized  officer,  stating  product  sales by each of the other
licensees or Sublicensees (if any) covered by the SKICR Agreement (to the extent
available to, and not subject to legal or contractual restrictions on disclosure
by,  CYTOGEN),  and will  make its  respective  personnel  available  to  answer
questions  and  otherwise  provide  information  with  respect  to  any  matters
reasonably  necessary for the LLC to calculate amounts due by the LLC to CYTOGEN
under Section 5 hereof.

     7.4   CURRENCY CONTROL RESTRICTIONS. In the event that the LLC is precluded
           -----------------------------
from  transferring  royalties  due  CYTOGEN  hereunder  at any time  during  the
Contract  Period  because the LLC has failed after  commercially  reasonable due
diligence  to  obtain  the  approval  of  such  transfer  from  the  appropriate
governmental   agency  responsible  for  control  of  currency  exchanges  of  a
particular  country in which the LLC has sold  Licensed  Products,  then the LLC
agrees (a) to deposit or to cause the deposit of such  royalties  to the account
of CYTOGEN  in a bank in such  country  designated  by the  beneficiary  of such
deposit;  (b)  to  provide  or to  cause  to be  provided  to  such  beneficiary
documentary  evidence of such deposits;  and (c) to remit or to cause remittance
of such deposits to such beneficiary immediately upon the subsequent approval of
such transfers by such governmental agency. The LLC further agrees that the form
of such  depository  account  shall  permit such  beneficiary  to  withdraw  the
deposited  amounts at will,  but shall permit the LLC to withdraw the  deposited
amounts  solely for the purpose of remitting  such  amounts to such  beneficiary
pursuant to the provisions of this Section 7.4.

     7.5   BOOKS  AND  RECORDS.  The LLC  agrees to  keep adequate  and complete
           -------------------
records showing all Commercial Sales and/or other revenues with respect to which
earned royalties and/or other payments are due CYTOGEN  hereunder.  Such records
shall  include  all  information  necessary  to  verify  the  total  amount  and
computation of earned  royalties and/or other payments  hereunder,  and shall be
open to inspection by CYTOGEN during  reasonable  business hours upon reasonable
notice to the extent necessary to verify the amount thereof.  Such inspection by
CYTOGEN shall be made not more often than once each Contract Year at the request
of CYTOGEN  (unless good cause is shown by CYTOGEN of the need for more frequent
inspection)  by an  auditor  appointed  by  CYTOGEN  and to whom  the LLC has no
reasonable   objection,   provided   that   such   auditor   shall  be  under  a
                          --------
confidentiality obligation to the LLC to reveal only that


                                       20
<PAGE>


information,  and  only to  CYTOGEN,  necessary  to  verify  the  royalties  due
hereunder.  In  addition,  such  inspection  shall be limited to a period not to
extend beyond three years after the date of receipt by the requesting Party of a
report  from the LLC  relating to such  records  pursuant to Section 7.1 hereof.
After such  three-year  period,  any such report and the records upon which such
report was based shall be deemed presumptively correct. The expenses of any such
audit  shall be  borne by the  party  requesting  the  audit  unless  the  audit
determines a discrepancy in favor of CYTOGEN of at least 10%, in which event the
audit expenses shall be borne by the LLC. Notwithstanding the foregoing, CYTOGEN
shall, at reasonable times and upon reasonable  notice,  be granted access after
such  three-year  period to such records (to the extent retained by the LLC) for
purposes of preparing tax returns and related materials.

     8.    TAXATION OF PAYMENTS.  Insofar as any earned  royalties which are due
CYTOGEN hereunder are subject to taxation by any country under the provisions of
the tax laws of that country, then CYTOGEN hereby authorizes the LLC to withhold
such taxes from the  payments  which are payable to CYTOGEN in  accordance  with
this  Agreement if the LLC is either  required to do so under such country's tax
laws or directed to do so by an agency of such  country's  government.  Whenever
the LLC deducts such tax from any payments  due CYTOGEN,  the LLC shall  furnish
CYTOGEN with a tax certificate showing the payment of such tax to the government
of such country.  In the event such taxes are assessed against the LLC by reason
of its failure to withhold such taxes from any payments  which have been paid to
CYTOGEN in accordance with this Agreement,  then CYTOGEN agrees to reimburse the
LLC for such tax  assessment  but not for any  fine,  penalty,  fee or  interest
related to the LLC's  failure to  withhold,  pay or make timely  payment of such
taxes.

     9.    PRODUCT LIABILITY DISCLAIMERS.

     9.1   PRODUCT  LIABILITY  DISCLAIMER  BY  PROGENICS.  Progenics assumes  no
           ---------------------------------------------
responsibility for the manufacture, product specifications, end use or provision
of any Licensed  Products that are  manufactured  or provided by or for, or sold
by, the LLC or any Sublicensee.  All warranties in connection with such Licensed
Products  made or provided by the LLC or any  Sublicensee  shall not directly or
impliedly  obligate  Progenics in any manner whatsoever under such warranties or
otherwise.

     9.2   PRODUCT   LIABILITY  DISCLAIMER   BY  CYTOGEN.  CYTOGEN   assumes  no
           ---------------------------------------------
responsibility for the manufacture, product specifications, end use or provision
of any Licensed  Products that are  manufactured  or provided by or for, or sold
by, the LLC or any Sublicensee.  All warranties in connection with such Licensed
Products  made or provided by the LLC or any  Sublicensee  shall not directly or
impliedly  obligate  CYTOGEN in any manner  whatsoever  under such warranties or
otherwise.

     9.3   PRODUCT  LIABILITY   DISCLAIMER  BY  THE  LLC.  The  LLC  assumes  no
           ---------------------------------------------
responsibility  for the  manufacture or product  specifications  of any products
which are manufactured by or for Progenics or CYTOGEN except for the manufacture
or product specifications of materials made by or for the LLC. Any warranties in
connection  with such  products  made by  Progenics  or  CYTOGEN as user of such
products shall not directly or impliedly obligate the LLC.


                                       21
<PAGE>


     10.   INDEMNIFICATION AND INFRINGEMENT.

     10.1  INDEMNIFICATION.
           ---------------

           10.1.1  BY PROGENICS.  Progenics  shall indemnify,  defend  and  hold
                   ------------
CYTOGEN and its Affiliates  harmless from and against any and all claims,  suits
or demands for liability,  damages,  losses,  costs and expenses,  including the
reasonable costs and expenses of counsel (collectively,  "Losses"),  arising out
                                                          ------
of any breach of the representations  and warranties,  or the failure to perform
when and as required any of the  covenants or  agreements,  made by Progenics in
this Agreement.

           10.1.2 BY CYTOGEN. CYTOGEN shall indemnify,  defend and hold the LLC,
                  ----------
its  Affiliates  and  any  Sublicensee of  the  LLC hereunder  harmless from and
against any and all Losses arising out of (i) any breach of the  representations
and  warranties,  or the  failure to  perform  when and as  required  any of the
covenants  or  agreements,  made by  CYTOGEN  in  this  Agreement  or  (ii)  any
infringement  or purported  infringement  of Third Party  intellectual  property
rights by  practicing  the  Licensed  CYTOGEN  Patents or the CYTOGEN  Technical
Information.

           10.1.3 BY THE LLC.  The LLC shall  indemnify, defend and hold CYTOGEN
                  ----------
and its  Affiliates  harmless from and against any and all Losses arising out of
(i) any breach of the representations and warranties,  or the failure to perform
when and as required any of the covenants or agreements, made by the LLC in this
Agreement  or (ii) any claim by a Third Party that any  Licensed  Product  made,
used or sold by or on  behalf  of the LLC or any  sublicense  thereof  infringes
patent rights of such Third Party  (except  insofar as any such claim gives rise
to an indemnification  obligation of Progenics under Section 10.1.1 hereof or of
CYTOGEN under Section 10.1.2 hereof).

     10.2  INFRINGEMENT OF LICENSED CYTOGEN PATENTS. In the event that any Party
           ----------------------------------------
becomes  aware  that any Third  Party is  infringing  any claim or claims of any
issued patent included within the Licensed  CYTOGEN Patent or CYTOGEN  Technical
Information, then such Party shall immediately advise the other Parties, and the
Parties  shall  consult  with  each  other  as to  the  most  effective  way  of
proceeding. Under such circumstances:

           (a)  the  LLC,  as the  exclusive  icensee  of the  Licensed  CYTOGEN
Patents,  shall  have the  right,  but not the  obligation,  and  subject to any
applicable  Third Party  rights,  to commence and  prosecute an action under the
Licensed CYTOGEN Patents against any such Third Party infringer,  in which event
the LLC shall bear the costs of such  action and shall be entitled to retain any
recovery resulting therefrom;

           (b) if the LLC  declines or fails to commence and/or  prosecute  such
action, then CYTOGEN shall be entitled to commence and prosecute an action under
the appropriate Licensed CYTOGEN Patents against such Third Party infringer,  in
which event CYTOGEN shall bear the costs of such action and shall be entitled to
retain any recovery resulting therefrom.

The  Parties  shall  cooperate  fully with each  other in any such  proceedings,
consulting as to  litigation  strategies  and other matters  related to any such
proceedings,  and shall,  among other things,  furnish  information and evidence
when so requested by the other,  including testimony by the requested


                                       22
<PAGE>


Party, its agents and employees,  as may be required by the Party commencing and
prosecuting such action.

     10.3  PROCEDURE.  Each  Party  shall  promptly  notify  the  other Party in
           ---------

writing in the event it becomes aware of a claim for which  indemnification  may
be  sought  hereunder.  In  case  any  proceeding  (including  any  governmental
investigation)  shall be  instituted  involving  any Party in  respect  of which
indemnity  may  be  sought   pursuant  to  this  Section  10,  such  Party  (the
"Indemnified  Party") shall promptly  notify the other Party (the  "Indemnifying
 ------------------                                                 ------------
Party") in writing and the Indemnifying  Party and Indemnified  Party shall meet
-----
to discuss  how to respond to any  claims  that are the  subject  matter of such
proceeding.  The Indemnified  Party shall cooperate fully with the  Indemnifying
Party in defense of such matter.  The  Indemnifying  Party,  upon request of the
Indemnified  Party,   shall  retain  counsel  reasonably   satisfactory  to  the
Indemnified  Party to represent the Indemnified Party and shall pay the fees and
expenses of such  counsel  related to such  proceeding.  In any such claim,  the
Indemnified  Party shall have the right to retain its own counsel,  but the fees
and expenses of such counsel  shall be at the expense of the  Indemnified  Party
unless (i) the Indemnifying  Party and the Indemnified Party shall have mutually
agreed to the  retention of such  counsel or (ii) the named  parties to any such
claim (including any impleaded  parties) include both the Indemnifying Party and
the  Indemnified  Party and  representation  of both Parties by the same counsel
would be inappropriate  due to actual or potential  differing  interests between
them. All such fees and expenses  shall be reimbursed as they are incurred.  The
Indemnifying  Party shall not be liable for any settlement of any claim effected
without its written consent,  but, if settled with such consent or if there be a
final judgment for the plaintiff, the Indemnifying Party agrees to indemnify the
Indemnified  Party  from and  against  any loss or  liability  by reason of such
settlement or judgment.  The  Indemnifying  Party shall not, without the written
consent of the  Indemnified  Party,  effect  any  settlement  of any  pending or
threatened claim in respect of which the Indemnified Party is, or arising out of
the same set of facts  could have been,  a party and  indemnity  could have been
sought hereunder by the Indemnified  Party,  unless such settlement  includes an
unconditional release of the Indemnified Party from all liability on claims that
are the subject matter of such proceeding.

     11.   TERM AND TERMINATION.

     11.1  TERM.  Unless sooner terminated  in accordance with Section 11.2, the
           ----
Original  Agreement  shall  continue as amended and restated  hereby,  and shall
cease  upon the last to  subsist  of any  Valid  Claim of any  Licensed  CYTOGEN
Patents;  provided,  however,  that this Agreement shall not terminate until the
          --------   -------
end of the last Royalty Term unless sooner terminated in accordance with Section
11.2; provided,  further, that the provisions of Sections 7.1, 7.5, 9, 10, 11.1,
      --------   -------
12 and 14 hereof shall survive any such termination or expiration.

     11.2  TERMINATION.  This  Agreement may  be terminated at any time prior to
           -----------
the end of the term set forth in Section 11.1 hereof, as follows:

           11.2.1  FOR BREACH.  In the event  either the LLC or Progenics on the
                   ----------
one hand,  or  CYTOGEN  on the other  hand,  shall  breach  any of the  material
representations  or  warranties  or any  material  term,  condition or agreement
contained herein made or to be kept, observed or performed by it, then the other
such Party may terminate this Agreement,  at its option and without prejudice to
any of its other legal or  equitable  rights and  remedies,  by giving the other


                                       23
<PAGE>


such Party 60 days' notice in writing,  identifying with reasonable  specificity
the breach, unless (in the case of a breach of any term, condition or agreement)
the notified Party within such 60-day period shall have cured the breach.

           11.2.2  FOR BANKRUPTCY.  (a) In the event (i) Progenics or the LLC on
                   --------------

the one hand,  or CYTOGEN on the other hand,  shall suspend  business,  or shall
file a voluntary  petition or any answer admitting the jurisdiction of the court
and the material  allegations  of, or shall consent to an  involuntary  petition
pursuant to or purporting to be pursuant to any reorganization or insolvency law
of any  jurisdiction,  or shall make an assignment for the benefit of creditors,
or shall apply for or consent to the  appointment  of a receiver or trustee of a
substantial  part of its  property,  and (ii) no  Affiliate  of such Party shall
undertake  to assume its  obligations  under the  provisions  of this  Agreement
within 90 days from the date on which such Party  becomes so  disabled,  then to
the extent  permitted  by law the other such  Party may  thereafter  immediately
terminate  this  Agreement by giving  written notice of termination to the other
Parties.

           (b) In the event this Agreement is terminated under Section 11.2.2(a)
as a result of an event  covered  thereby with  respect to CYTOGEN,  and the LLC
terminates  this  Agreement  under  Section  11.2.2(a)  or CYTOGEN  rejects this
Agreement  pursuant to Section 365 of the U.S.  Bankruptcy  Code, all rights and
licenses granted under or pursuant to this Agreement by CYTOGEN, to the LLC are,
and shall  otherwise be deemed to be, for purposes of Section 365(n) of the U.S.
Bankruptcy Code, licenses of rights to "intellectual  property" as defined under
Section 101(35A) of the U.S.  Bankruptcy  Code.  CYTOGEN agrees that the LLC, as
licensee  of such  rights  under  this  Agreement,  shall  retain  and may fully
exercise all of its 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 CYTOGEN under the U.S.  Bankruptcy  Code, the LLC shall
be entitled to a complete  duplicate of (or complete  access to, as appropriate)
any such intellectual property and all embodiments of such intellectual property
upon written  request  therefor by the LLC. Such  intellectual  property and all
embodiments  thereof  shall be promptly  delivered  to the LLC (i) upon any such
commencement of a bankruptcy  proceeding  upon written  request  therefor by the
LLC, unless CYTOGEN elects to continue to perform all of its  obligations  under
this Agreement or (ii) if not delivered  under (i) above,  upon the rejection of
this Agreement by or on behalf of CYTOGEN upon written  request  therefor by the
LLC.  CYTOGEN shall not interfere with the rights of the LLC as provided in this
Agreement,  or any agreement supplementary hereto, to such intellectual property
(including  all such  embodiments  thereof),  including  any right of the LLC to
obtain such intellectual property (or such embodiment) from any other entity.

           11.2.3  THE LLC  UPON TERMINATION  OF THE SKICR LICENSE.  The LLC may
                   -----------------------------------------------
terminate  this  Agreement  by giving  CYTOGEN 30 days  written  notice upon the
termination of the SKICR  License;  provided  that,  without  limiting the other
                                    --------
rights and  remedies of the Parties,  each of Progenics  and CYTOGEN may seek an
appropriate  remedy  against  the  other  if the  other is  responsible  for the
termination of the SKICR License.

           11.2.4  EFFECT OF TERMINATION OR EXPIRATION.  Upon the  expiration of
                   -----------------------------------
the Royalty Term applicable to any Licensed  Product in a country,  the Licensed
CYTOGEN Patent and CYTOGEN  Technical  Information with respect to such Licensed
Product  in  such   country   shall   convert  to  a   perpetual,   irrevocable,
non-exclusive, transferable, paid-up, royalty-free license with


                                       24
<PAGE>


the right to  sublicense  in such  country to  develop  and  commercialize  such
Licensed Product in such country.

     11.3  ACCRUED  RIGHTS AND OBLIGATIONS.  Termination of this Agreement shall
           -------------------------------
not relieve any Party of any rights or  obligations  then  accrued  hereunder or
which by the terms hereof extend beyond the date of such termination.

     12.   EFFECT  OF  TERMINATION  ON SUBLICENSEE.  Upon  termination  of  this
           ---------------------------------------
Agreement  by the LLC or CYTOGEN  pursuant to Section  11.2.1 or Section  11.2.2
hereof,  any Third  Party  licensee  of the LLC which  has not  breached  in any
material  respect its sublicense  related to the Licensed CYTOGEN Patents or the
CYTOGEN  Technical  Information  shall be  entitled  to receive a license to the
Licensed  CYTOGEN Patents and the CYTOGEN  Technical  Information  directly from
CYTOGEN  granting  rights  substantially  the  same  as  those  granted  in such
sublicense and containing  obligations as a licensee  similar to those set forth
in this Agreement.

     13.   EXPORT  LICENSES.  This  Agreement  is  subject  to any  restrictions
           ----------------
concerning  the export of  products  or  technical  information  from the United
States which may be imposed by the United States. Accordingly, each Party agrees
that it will not  export,  directly or  indirectly,  any  technical  information
acquired  under this  Agreement or any  products  utilizing  any such  technical
information to any country for which the United States  Government or any agency
thereof at the time of export  requires an export license or other  governmental
approval,  without  first  obtaining  the  written  consent  to do so  from  the
Department  of Commerce or other  agency of the United  States  Government  when
required by an applicable statute or regulation.

     14.   MISCELLANEOUS PROVISIONS.
           ------------------------

     14.1  ASSIGNABILITY, ETC..  Except  as expressly  provided  herein, neither
           ------------------
this  Agreement  nor any interest  hereunder  shall be  assignable  by any Party
without the written consent of the others, and any attempted  assignment without
such  consents  shall be null and void.  Without the consent of any other Party,
this  Agreement  may be assigned by any Party to any wholly owned  subsidiary of
such  Party  that  agrees in writing  with each  other  Party to be jointly  and
severally  liable with the assigning  Party for the timely  satisfaction  of all
obligations of the assigning Party hereunder;  provided,  however,  that no such
                                               --------   -------
assignment  shall  relieve the  assigning  Party of its  obligations  hereunder,
including in  connection  with an  assignment  by the LLC to Progenics or any of
Progenics' Affiliates. Notwithstanding the foregoing, without the consent of any
other Party,  this  Agreement  may be assigned by the LLC to Progenics or any of
Progenics'  Affiliates.  This Agreement shall be binding upon the successors and
permitted  assignees of the Parties.  Any such  successor or permitted  assignee
shall be  subject to the same  rights  and  obligations  as the  original  Party
hereunder. Notwithstanding the foregoing, a sale of assets by the LLC related to
the Licensed  Products  shall be deemed to be an  assignment  under this Section
14.1.

     14.2  NOTICES.  All notices and other communications provided for hereunder
           -------
shall be in writing and shall be mailed or delivered to the business  address of
the respective Parties aforementioned,  or to such other address or addresses as
either  Party shall  designate  in writing to the others.  All such  notices and
communications  shall be considered  given and/or  delivered:  (i) when given if
delivered  in person or sent by  facsimile  and  acknowledged  by a  responsible
person at


                                       25
<PAGE>


the office of the recipient;  (ii) one day after being sent by a major overnight
courier;  or (iii) four days  after  being  mailed by  registered  mail,  return
receipt  requested,  at the  business  address  of  the  respective  Parties  as
specified above. All notices or communications required or permitted to be given
or sent to the LLC shall also be given or sent to  Progenics  (if such notice or
communication  is given or sent by  CYTOGEN)  or to CYTOGEN  (if such  notice or
communication is given or sent by Progenics).

         If to Progenics or the LLC, to:

              Progenics Pharmaceuticals, Inc.
              777 Old Saw Mill River Road
              Tarrytown, New York 10591
              Telecopy: 914-789-2856
              Attention:  Mark R. Baker, Senior Vice President & General Counsel

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

              Dewey Ballantine LLP
              1301 Avenue of the Americas
              New York, New York 10019
              Telecopy: 212-259-6333
              Attention:    Donald Murray
                            Stanton J. Lovenworth

         If to CYTOGEN, to:

              Cytogen Corporation
              650 College Road East
              Princeton, New Jersey 08540|
              Telecopy: 609-452-2317
              Attention: William J. Thomas, Senior Vice President
                         and General Counsel

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

              Morgan, Lewis & Bockius LLP
              502 Carnegie Center
              Princeton, New Jersey 08540
              Telecopy: 609-919-6701
              Attention: Randall B. Sunberg

or to such other  address or  addresses  as any such party may from time to time
designate as to itself by like notice.

     14.3  INDEPENDENT CONTRACTORS.  No agency,  partnership or joint venture is
           -----------------------
hereby established.  None of Progenics,  CYTOGEN or the LLC shall enter into, or
incur, or hold itself out to Third Parties as having  authority to enter into or
incur on behalf of the other Parties any  contractual  obligations,  expenses or
liabilities whatsoever, except as expressly provided herein.


                                       26
<PAGE>


     14.4  COUNTERPARTS.  This  Agreement  may  be  executed  simultaneously  in
           ------------
multiple  counterparts,  each of which shall be deemed to be an original but all
of which together shall constitute one and the same agreement.

     14.5  ENTIRE  UNDERSTANDING.   This   Agreement  constitutes   the   entire
           ---------------------
understanding  between the Parties with respect to the subject matter hereof. No
modifications,  extensions, or waiver of any provisions hereof or any release of
any right  hereunder  shall be valid,  unless the same is in  writing,  contains
reference to this Agreement and sets forth the plan or intention to modify same,
and is consented to by all Parties.

     14.6  HEADINGS.  The  headings in  this Agreement  are intended  solely for
           --------
convenience  of reference  and shall be given no effect in the  construction  or
interpretation of this Agreement.

     14.7  NO  IMPLIED  RIGHTS.  Except   as  expressly  provided  for  in  this
           -------------------
Agreement, nothing contained herein shall be construed as conferring any license
or other rights, by implication or estoppel,  under any patent (including design
patent and  utility  model  patent) or patent  application,  or any  copyrights,
trademarks, trade names or trade dress.

     14.8  NO WAIVER.  The failure of any  Party at any time or times to require
           ---------
performance of any provision  hereof shall in no manner affect the right of such
Party at a later  time to  enforce  the  same.  No  waiver  by any  Party of any
condition, or of the breach of any provision, term, covenant,  representation or
warranty  contained in this Agreement,  whether by conduct or otherwise,  in any
one or more  instances,  shall be deemed  to be or  construed  as a  further  or
continuing waiver of any such condition or of the breach of any other provision,
term, covenant, representation or warranty of this Agreement.

     14.9  PUBLICITY.
           ---------

           (a) In the absence of prior written approval of the other Parties, no
Party shall originate any publicity, news release, or other public announcement,
written or oral,  whether to the public  press,  to  stockholders  or otherwise,
relating to this  Agreement,  to any amendment or activities  hereunder,  unless
such announcement is required by law to be made, in which case the provisions of
Section 14.9(b) shall apply. The Party making any such  announcement  shall give
the other Parties an opportunity to review the announcement before it is made.

           (b) A Party  may only  disclose  the  terms of this Agreement  or any
further amendments to the Agreement if such Party reasonably  determines,  based
on advice  from its  counsel,  that it is required  to make such  disclosure  by
applicable law, regulation or legal process, including without limitation by the
rules or regulations of the U.S.  Securities and Exchange  Commission ("SEC") or
similar  regulatory  agency in a  country  other  than the U.S.  or of any stock
exchange or NASDAQ, in which event such Party shall provide prior notice of such
intended  disclosure to the other Parties  sufficiently in advance to enable the
other  Parties  to seek  confidential  treatment  or other  protection  for such
information  unless the disclosing  Party is prevented by law or regulation from
providing  such  advance  notice  and shall  disclose  only  such  terms of this
Agreement or such  further  amendment(s)  as such  disclosing  Party  reasonably
determines,  based on advice from its counsel,  are required by applicable  law,
regulation  or legal  process to be  disclosed.


                                       27
<PAGE>


In the event  that  either  Party  determines  that it must  publicly  file this
Agreement  or such  further  amendment(s)  with the SEC,  such  Party  shall (i)
initially file a redacted copy of this Agreement or such further amendment(s) in
a form mutually  agreeable to the Parties,  (ii) request,  and use  commercially
reasonable efforts to obtain,  confidential treatment of all terms redacted from
such  Agreement  or such further  amendment(s),  (iii) permit the other Party to
review and approve  such  initial  request for  confidential  treatment  and any
subsequent  correspondence  with respect  thereto at least two (2) business days
prior to its submission to the SEC, and (iv) promptly deliver to the other Party
any written  correspondence  received by it or its representatives  from the SEC
with respect to such  confidential  treatment  request and  promptly  advise the
other   Party  of  any  other   material   communications   between  it  or  its
representatives  with  the  SEC  with  respect  to such  confidential  treatment
request.

     14.10 PROMOTION AND ADVERTISING. Nothing contained  in this Agreement shall
           -------------------------
be  construed  as  conferring  on any  Party  any  right to use in  advertising,
publicity  or other  promotional  activities  any  name,  tradename,  trademark,
service mark or other  designation  (including any contraction,  abbreviation or
simulation of any of the  foregoing of any other Party);  and, each Party agrees
not to use any  designation  of any  other  Party  in any  promotional  activity
associated with this Agreement, or with a Licensed Product,  without the express
written approval of such other Party.

     14.11 ARBITRATION.  Any  dispute  arising   out  of  or  relating   to  any
           -----------
provisions of this Agreement  shall be finally settled by arbitration to be held
in New York, New York, under the auspices and the current commercial arbitration
rules of the American Arbitration Association. Arbitration shall be initiated by
delivery  of a notice  (an  "Arbitration  Notice")  by any  Party  to the  other
                             -------------------
Parties. Such arbitration shall be conducted by one arbitrator mutually selected
and  approved by the Parties to the  dispute.  If within 20 calendar  days after
receipt of the Arbitration  Notice the Parties to the dispute have not agreed on
a mutually acceptable  arbitrator,  the American Arbitration  Association in New
York,  New York shall be  retained to appoint an  arbitrator  within 30 calendar
days after the receipt of the Arbitration  Notice.  The  arbitrator's  authority
shall be limited to determining the issue or question presented in each instance
and shall  not  extend to any other  aspect of this  Agreement  or the  Parties'
relationship  generally.  Judgment upon any award rendered may be entered in any
court  having  jurisdiction,  or  application  may be made to such  court  for a
judicial  acceptance of the award and an order of  enforcement,  as the case may
be.

     14.12 CONFIDENTIALITY.
           ---------------

           14.12.1  As  used in  this Section  14.12, "Confidential Information"
means confidential and proprietary business,  technical or financial information
relating  to  the  collaboration  contemplated  hereby,  including  the  CYTOGEN
Technical Information, of any other Party (the "Confidential Information").
                                                ------------------------

           14.12.2  In  order to  protect the  Confidential  Information  of any
Party (in such capacity,  the "Disclosing  Party") that has become  available to
                               -----------------
any other Party (in such capacity,  the "Receiving Party"), each Party agrees as
                                         ---------------
follows:

           (a)  Each Party  agrees that it will  make no use of any Confidential
Information  except  in  furtherance  of  the  purposes   contemplated  by  this
Agreement.


                                       28
<PAGE>


           (b)  Each  Party agrees that  it will not,  without the prior written
consent  of  the  other  Parties,  disclose  to  any  Third  Party  Confidential
Information  (which for purposes of this Section  14.12.2(b)  shall  include the
terms or  existence of this  Agreement  or of the LLC  Agreement or the Services
Agreement or other matters relating to the collaboration contemplated hereby and
thereby)  received  in its  capacity as a Receiving  Party  during the  Contract
Period and for a period of five years thereafter.

           (c)  Notwithstanding the foregoing:

           (i)  Each Party  may disclose  Confidential  Information to  those of
           its  representatives, employees  and agents  ("Representatives")  who
                                                          ---------------
           have a need to know such Confidential  Information in relation to the
           matters   discussed   herein  and  who  are  under   obligations   of
           confidentiality  and non-use consistent  with those set forth herein.
           Any unauthorized disclosure of Confidential  Information by a Party's
           Representatives  shall  be a  breach by  such Party  of this  Section
           14.12.

           (ii)  Disclosure of  Confidential  Information  is  permitted  to the
           extent that such disclosure is required pursuant to applicable  laws,
           rules  or  regulations  or  government requirement  or  court  order,
           provided  however, that the Receiving Party shall promptly notify the
           Disclosing Party  in writing of  the existence  or imposition  of any
           such requirement or order and cooperate with the Disclosing  Party in
           seeking an appropriate protective  order or other reliable  assurance
           that  confidential   treatment  will  be  accorded  the  Confidential
           Information.

           14.12.3  The   provisions  governing   confidentiality   and  non-use
contained in this Section 14.12 shall not apply to any Confidential  Information
which:

           (a)  the  Receiving Party  can establish  was known  to the Receiving
Party prior to  disclosure  under or in  connection  with this  Agreement by the
Disclosing Party;

           (b)  was in  the public domain  or the subject of public knowledge at
the time of disclosure under or in connection with this Agreement;

           (c)  becomes  part of  the public  domain or  the subject  of  public
knowledge through no breach by or act of default of the Receiving Party;

           (d)  is obtained by the Receiving Party from a Third Party other than
in breach of a legal or contractual  obligation of confidentiality  owed by such
Third Party to the Disclosing Party in respect  thereof,  the existence of which
such obligation was known or should have been known by the Receiving Party; or

           (e)  the Receiving Party can establish was independently developed by
it without reference to Confidential Information received.


                                       29
<PAGE>


           14.12.4  Termination   of  this   Agreement  shall  not  affect   the
obligations   concerning   confidentiality   and  non-use  of  the  Confidential
Information as set forth in this Section 14.12.

     14.13 NO  THIRD  PARTY  BENEFICIARIES.  This  Agreement  is  solely for the
           -------------------------------
benefit of the  Parties  and should not be  construed  to confer  upon any other
Person any remedy, claim, liability, right of reimbursement,  claim of action or
other right.

     14.14 GOVERNING  LAW.  This Agreement shall  be interpreted, construed, and
           --------------
governed in accordance with the laws in effect in the State of New York, without
reference to conflict of laws principles.

     14.15 SKICR AGREEMENT.  Pursuant to Section III.D.4 of the SKICR Agreement,
           ---------------
the Parties hereby  reference the SKICR Agreement and all rights which revert to
SKICR upon  termination  of the SKICR  Agreement.  In  accordance  with  Section
III.D.8 of the SKICR Agreement,  this Agreement shall  automatically be modified
or terminated, in whole or in part, upon any relevant modification,  in whole or
in part,  of the SKICR  Agreement.  Such  modification  or  termination  of this
Agreement  shall be consistent  with and reflect the relevant  modifications  or
terminations of the SKICR Agreement.


                                       30


<PAGE>

     IN WITNESS  WHEREOF,  the  Parties  have each caused  these  presents to be
signed by their respective officers thereunto duly authorized.


                                PROGENICS PHARMACEUTICALS, INC.



                                By: /s/ Mark R. Baker
                                  ----------------------------------------------
                                  Name:   Mark R. Baker
                                  Title:  Senior Vice President, General Counsel
                                          & Secretary


                                CYTOGEN CORPORATION



                                By: /s/ Michael D. Becker
                                   ---------------------------------------------
                                   Name: Michael D. Becker
                                   Title: President and Chief Executive Officer


                                PSMA DEVELOPMENT COMPANY LLC



                                By: /s/ Mark R. Baker
                                   ---------------------------------------------
                                   Name: Mark R. Baker
                                   Title: Assistant Secretary





       Signature Page to Amended and Restated PSMA/PSMP License Agreement

<PAGE>


[**]