[CONFIDENTIAL  TREATMENT  REQUESTED.   CONFIDENTIAL  PORTIONS  OF  THIS
   AGREEMENT  HAVE BEEN REDACTED AND HAVE BEEN  SEPARATELY  FILED WITH THE
   COMMISSION.]




                      LICENSE AND COLLABORATION AGREEMENT
                      -----------------------------------

            THIS LICENSE AND  COLLABORATION  AGREEMENT dated as of September 15,
1995 (the "Agreement"), is entered into between THE IMMUNE RESPONSE CORPORATION,
a Delaware corporation ("IRC"), having a place of business at 5935 Darwin Court,
Carlsbad, California 92008, U.S.A., and TRINITY MEDICAL GROUP, CO., LTD., a Thai
limited  company  ("Trinity"),  having a place of business at 425/5 Silom No. 7,
Silom Road, Bangkok 10500, Thailand.

                              W I T N E S S E T H :

         WHEREAS,  IRC owns or has rights in certain  technology  relating  to a
certain  immunotherapeutic product which uses inactivated human immunodeficiency
virus ("HIV") depleted of its gp120 envelope administered in Incomplete Freund's
Adjuvant.

         WHEREAS,  IRC and  Trinity  desire to  collaborate  together to conduct
clinical  development  of, and to obtain  regulatory  approval  to market,  such
product in Thailand and certain other  countries of Asia for use in treatment of
HIV infection, on the terms and subject to the conditions of the Agreement.

         WHEREAS,   Trinity  desires  to  fund  such  clinical  development  and
regulatory activities, and to obtain the rights to commercialize such product in
such  countries  for use in the  treatment  of HIV  infection,  on the terms and
subject to the conditions of the Agreement.

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

                                    ARTICLE 1

                                   DEFINITIONS
                                   -----------

         For  purposes of the  Agreement,  the terms  defined in this  Article 1
shall have the respective meanings set forth below;

         1.1  "Affiliate"  shall mean,  with  respect to any  Person,  any other
Person which  directly or indirectly  controls,  is  controlled  by, or is under
common  control with,  such Person.  A Person shall be regarded as in control of
another  Person if it owns, or directly or indirectly  controls,  at least forty
percent  (40%) of the  voting  stock or other  ownership  interest  of the other
Person,  or if it directly or indirectly  possesses the power to direct or cause
the  direction of the  management  and policies of the other Person by any means
whatsoever.

         1.2  "Development  Program"  shall  mean the  program  to  conduct  the
clinical development of the Product in the Territory, and to conduct the related
activities to obtain regulatory  approval to market the Product in the Territory
for use in the Field, as described generally in the Development Workplans.

<PAGE>

         1.3 "Development  Workplan" shall mean, with respect to each country in
the Territory,  the written workplan to conduct the clinical  development of the
Product,  and to conduct the related activities to obtain regulatory approval to
market the Product in such country for use in the Field, as set forth in Exhibit
A with  respect to  Thailand,  and as  prepared  pursuant to the  provisions  of
Section 3.1.1 below with respect to each other country in the Territory, in each
case as the same may be revised from time to time pursuant to the  provisions of
Section 3.1.3 below.

         1.4 "FDA" shall mean the United States Food and Drug Administration, or
the successor thereto.

         1.5 "Field" shall mean the treatment of HIV infection.

         1.6 "First  Commercial  Sale" shall mean,  with respect to any country,
the first sale or  distribution  for use or consumption by the general public of
the Product in such  country  after the  required  marketing  approval  has been
granted by the governing health authority of such country.

         1.7 "GMP" shall mean current Good Manufacturing  Practices  promulgated
by the FDA in the United States.

         1.8 "Manufacturing  Cost" shall mean the fully-burdened cost, expressed
on a per unit manufactured  basis, of manufacturing  the Product,  together with
the  packaging  thereof,  including  the cost of  materials,  direct  labor  and
benefits,  and overhead, all as determined in accordance with generally accepted
accounting  principles  and  consistently  with  the  manufacturer's  accounting
practices for other products manufactured.  Materials, direct labor and benefits
and overhead shall be further defined as follows:

            1.8.1  "Materials"  shall include those items which form an integral
and  direct  part of the bulk  form of the  Product  and are  necessary  for its
production, as well as cartons, labels, package inserts and shippers.

            1.8.2  "Direct  Labor and  Benefits"  shall  include that portion of
basic wages,  labor and related  payroll  taxes and employee  benefits  spent in
actual  production of the  particular  Product  which can be identified  with or
charged to the Product.

            1.8.3  "Overhead" shall include all operating  expenses  incurred by
and  in  support  of  the  particular  manufacturing  cost  centers,  purchasing
department  and  quality  assurance  operations,  with  respect to the  Product,
including the following:

              -      Indirect labor, related payroll taxes and employee benefits
              -      Depreciation
              -      Taxes
              -      Insurance
              -      Rent
              -      Repairs and maintenance
              -      Supplies
              -      Utilities
              -      Factory administrative expenses

                                      -2-
<PAGE>

            1.9  "Manufacturing  Know-How"  shall mean all information and data,
including, but not limited to, formulae, procedures,  protocols,  techniques and
results of experimentation  and testing;  which are necessary or useful to make,
or to seek  regulatory  approval to make, the Product in Thailand for use in the
Field, in which IRC has an ownership or other  licensable  interest and which is
in the  possession of IRC on the date of the Agreement or thereafter  during the
term of the Agreement.

            1.10 "Person"  shall mean an individual,  corporation,  partnership,
trust, business trust,  association,  joint stock company,  joint venture, pool,
syndicate,  sole  proprietorship,   unincorporated  organization,   governmental
authority or any other form of entity not specifically listed herein.

            1.11 "Product" shall mean a certain  immunotherapeutic product which
uses  inactivated HIV depleted of its gp120 envelope  administered in Incomplete
Freund's Adjuvant.

            1.12  "Product  Know-How"  shall  mean  all  information  and  data,
including, but not limited to, formulae, procedures,  protocols,  techniques and
results of  experimentation  and testing,  which are necessary or useful to use,
develop,  sell,  distribute  or seek  regulatory  approval in any country in the
Territory  to  market  the  Product  for use in the  Field,  in which IRC has an
ownership or other licensable  interest and which is in the possession of IRC on
the date of the Agreement or thereafter during the term of the Agreement.

            1.13 "Product  Specifications" shall mean the specifications for the
manufacture of the Product as established by IRC, as the same may be modified by
IRC from time to time.

            1.14 "Royalty Term" shall mean,  with respect to each country in the
Territory,  the period of fifteen (15) years commencing on the date of the First
Commercial Sale of the Product in such country.

            1.15  "Stock  Purchase  Agreement"  shall  mean the  Stock  Purchase
Agreement dated as of the date hereof,  between IRC and Trinity (as the same may
be amended or restated from time to time).

            1.16 "Territory" shall mean Thailand,  Cambodia,  Burma,  Singapore,
Vietnam, Sri Lanka, Indonesia, Malaysia, the Philippines and Laos.

            1.17 "Third Party" shall mean any Person other than IRC, Trinity and
their respective Affiliates.

                                   ARTICLE 2

                         REPRESENTATIONS AND WARRANTIES

         Each  party  hereby  represents  and  warrants  to the  other  party as
follows:

            2.1 Existence and Power.  Such party (a) is a corporation or limited
company  (as the case  may be)  duly  organized,  validly  existing  and in good
standing under the laws of the  jurisdiction  in which it is organized;  (b) has
the  requisite  power and  authority  and the legal right

                                      -3-
<PAGE>

to own and operate its property and assets,  to lease the property and assets it
operates under lease,  and to carry on its business as it is now being conducted
and (c) is in compliance with all  requirements of applicable law, except to the
extent that any  noncompliance  would not have a material  adverse effect on the
properties,  business,  financial or other condition of such party and would not
materially  adversely  affect such  party's  ability to perform its  obligations
under the Agreement.

            2.2 Authorization and Enforcement of Obligations. Such party (a) has
the  requisite  power  and  authority  and the  legal  right  to-enter  into the
Agreement  and to  perform  its  obligations  hereunder  and (b) has  taken  all
necessary  action on its part to  authorize  the  execution  and delivery of the
Agreement and the  performance of its obligations  hereunder.  The Agreement has
been duly  executed and  delivered on behalf of such party,  and  constitutes  a
legal, valid,  binding obligation,  enforceable against such party in accordance
with its terms.

            2.3 Consents.  All necessary consents,  approvals and authorizations
of all  governmental  authorities  and other Persons  required to be obtained by
such party in connection with the Agreement have been obtained.

            2.4 No Conflict. The execution and delivery of the Agreement and the
performance  of such party's  obligations  hereunder (a) do not conflict with or
violate  any  requirement  of  applicable  laws  or  regulations  and (b) do not
conflict with, or constitute a default under, any contractual obligation of such
party

            2.5  DISCLAIMER OF  WARRANTIES.  NOTHING IN THE  AGREEMENT  SHALL BE
CONSTRUED AS A  REPRESENTATION  MADE, OR WARRANTY  GIVEN, BY IRC THAT THE USE OF
ANY LICENSE GRANTED HEREUNDER WILL NOT INFRINGE THE PATENT OR PROPRIETARY RIGHTS
OF ANY OTHER PERSON.  FURTHERMORE,  IRC MAKES NO  REPRESENTATIONS OR WARRANTIES,
EXPRESS OR IMPLIED,  WITH RESPECT TO THE LICENSED  RIGHTS  HEREUNDER,  INCLUDING
WITHOUT LIMITATION,  ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE.

                                   ARTICLE 3

                              DEVELOPMENT PROGRAM
                              -------------------

         3.1 Development Workplans.

            3.1.1  Preparation of the Workplans.  The  Development  Workplan for
Thailand is set forth in Exhibit A hereto.  Not less than ninety (90) days prior
to the  anticipated  filing of the first  Investigational  New Drug  application
("IND") for the Product, or its equivalent,  with the governing health authority
in any other country in the  Territory,  or not less than ninety (90) days prior
to the  commencement of human clinical trials of the Product in any such country
if no such filing or  application  is required in such country,  IRC and Trinity
jointly  shall  prepare a  mutually  acceptable  Development  Workplan  for such
country.

         3.1.2 Content of the  Workplans.  In accordance  with the provisions of
Sections 3.2 below,  the Development  Workplan for each country in the Territory
(a) shall specify

                                      -4-
<PAGE>

generally the activities  necessary to obtain all applicable marketing approvals
required for the  commercial  sale,  distribution  or use of the Product in such
country for use in the Field, (b) shall set forth generally the structure of all
human clinical trials to be conducted in such country for the Product, (c) shall
identify the principal  investigators  for such clinical  trials,  and (d) shall
establish  the  required  resources  and  efforts  of IRC and  Trinity,  and the
required  funding by Trinity,  necessary to conduct such clinical  trials and to
obtain the required marketing approval to commercially sell,  distribute and use
the Product in such country as soon as commercially practicable, consistent with
prudent drug development practices.

         3.1.3  Modifications  to the  Workplans.  Prior to July 1 of each  year
during the term of the Development  Program,  the Project Leaders (as defined in
Section 4.1 below)  shall  recommend  to the parties  any  modifications  to the
Development  Workplan for each country  which they  determine to be necessary or
desirable.  Such  modifications  shall be effective only upon the mutual written
agreement  of  IRC  and  Trinity.   The  parties  additionally  may  revise  the
Development Workplan for each country upon the completion of each phase of human
clinical  trials of the Product in such country and otherwise from time to time,
upon the mutual written agreement of IRC and Trinity.

         3.2 Clinical Development. On the terms and subject to the conditions of
the  Agreement,  Trinity  diligently  shall  cause to be  conducted  such  human
clinical trials as the parties mutually  determine are necessary or desirable to
obtain  all  required  approvals  to market the  Product in each  country in the
Territory  for  use  in  the  Field,  all  in  accordance  with  the  applicable
Development Workplan.

            3.2.1   Trinity   shall  engage  one  or  more   clinical   research
organizations (each, a "CRO") of internationally-recognized standing, subject to
the  approval of IRC which  shall not be  unreasonably  withheld or delayed,  to
manage such human clinical trials.

            3.2.2 Trinity shall consult  generally with IRC with respect to each
such clinical trial.

            3.2.3 Each such clinical trial shall be conducted in accordance with
a protocol jointly prepared by, and in form and substance  mutually agreed to in
writing by IRC and Trinity.

            3.2.4  Trinity  shall  select  the  clinical   sites  and  principal
investigators for each such clinical trial, subject to the approval of IRC which
shall not be  unreasonably  withheld or delayed.  Each clinical site shall enter
into a  clinical  trials  site  agreement  with IRC and  Trinity  in the form of
Exhibit B hereto with only such  modifications  as necessary to reflect the name
of the clinical site, the name of the principal  investigator and the country in
which the clinical trial is conducted,  and as otherwise  expressly agreed to in
writing by IRC and  Trinity.  Trinity  shall cause its CRO to collect  from each
clinical Site, and to provide IRC with,  fully-executed  drug disposition forms,
in the form provided by IRC.

            3.2.5  Trinity  shall  cause its CRO to oversee  the conduct of each
such clinical trial. With respect to each clinical site, Trinity shall cause its
CRO to conduct a site initiation visit, subsequent monthly monitoring visits and
a site closing visit to ensure such site's  compliance in all material  respects
with all  requirements  of laws and  regulations  of the  United

                                      -5-
<PAGE>

States and the  applicable  countries of the Territory,  internal  institutional
procedures and  guidelines,  the applicable  protocol,  and good  laboratory and
clinical  practices  of the United  States and the  applicable  countries of the
Territory.

            3.2.6 IRC, at its sole  expense,  shall  provide each  clinical site
with the Product and placebo as identified in the applicable protocol for use in
the clinical trial to be conducted at such site.

            3.2.7 Trinity  promptly  shall cause its CRO to collect,  review and
evaluate all case record forms,  laboratory  report forms and related  documents
from each clinical site for  legibility,  completeness  and safety  information.
Trinity and its CRO shall  immediately  notify IRC of any serious or  unexpected
side effect, toxicity or sensitivity reaction, or any unexpected incidence,  and
the severity  thereof,  associated with any clinical trial.  Trinity and its CRO
shall work with each  clinical  site to collect any missing  information  and to
clarify or correct any inconsistencies or other ambiguous  information  provided
by such clinical  site.  With respect to each clinical site, on the first day of
each  month,  Trinity  shall  cause its CRO to  complete  and provide IRC with a
monthly  site  monitoring  report,  in a  form  reasonably  acceptable  to  IRC,
regarding all patient visits completed during the immediately preceding month at
such clinical site.

3.2.8 Each  clinical  site shall be  required to use case record and other forms
provided by IRC in connection  with such clinical  trial.  Not later than thirty
(30) days  following the completion of each such clinical  trial,  Trinity shall
cause its CRO to  provide  IRC with a copy of all case  record  forms  from such
clinical trial.

            3.2.9 IRC shall have the right,  but not the obligation,  to monitor
the  conduct  of,  and data  gathering  under,  each  such  clinical  trial  for
compliance  with all  requirements  of laws and regulations of the United States
and the applicable countries of the Territory, internal institutional procedures
and  guidelines,  the  applicable  protocol,  and good  laboratory  and clinical
practices of the United States and the  applicable  countries of the  Territory.
IRC also shall have the right, but not the obligation, to enter, upon reasonable
notice during normal  business hours,  the business  facilities of Trinity where
the clinical  trial records are  maintained  and during such time to review such
records and to consult with Trinity's staff with respect thereto.

            3.2.10 IRC, at its sole  expense,  shall  provide  Trinity with such
technical  assistance  regarding  the Product  Know-How as the parties  mutually
determine is reasonably  necessary or desirable to enable Trinity to conduct its
obligations  under the  Development  Program.  Such technical  assistance  shall
include  certain  training  of  Trinity  employees,  from  time to time,  at the
facilities of IRC in Carlsbad, California.

         3.3 Regulatory Filings and Applications.  IRC and Trinity jointly shall
prepare, file and prosecute all filings and applications necessary to obtain all
required marketing  approvals to commercially sell,  distribute and use (but not
to  manufacture)  the Product in the Territory  for use in the Field.  Each such
filing and  application  shall be in  Trinity's  name,  and shall be in form and
substance mutually acceptable to IRC and Trinity. Trinity shall be the owner and
party of record for all such filings and applications.  IRC shall be entitled to
cross reference all such filings and  applications by Trinity in connection with
the filing and prosecution of any filings and

                                      -6-
<PAGE>

applications  by IRC regarding the Product.  Trinity shall be entitled to review
and cross  reference all filings and  applications  by IRC regarding the Product
solely in  connection  with the filing and  prosecution  of all such filings and
applications by Trinity.

         3.4 Subcontracts.  Trinity may subcontract (including by the engagement
of one or more CRO's as required  under  Section  3.2.1  above)  portions of the
Development  Program to be performed by it in the normal  course of its business
without  the  prior   consent  of  IRC;   provided,   however,   that  (a)  such
subcontracting  shall not  involve  the  transfer  of Product  Know-How to Third
Parties without the prior express written consent of IRC; (b) the  subcontracted
party shall enter into a  confidentiality  agreement  with Trinity in accordance
with Section 10.2 below; (c) Trinity shall supervise such subcontract  work; and
(d) the subcontracted party shall be in compliance in all material respects with
all  requirements of laws and regulations of the United States and the countries
of the Territory,  together with all good laboratory practices and good clinical
practices of the United States and the applicable countries of the Territory.

         3.5  Conduct  of  Development   Program.   Trinity  shall  conduct  its
obligations  under the  Development  Program in good scientific  manner,  and in
compliance  in  all  material   respects  with  all  requirements  of  laws  and
regulations  of the United  States and the  countries of the  Territory  and all
applicable good laboratory  practices and good clinical  practices of the United
States and the applicable countries of the Territory.

         3.6 Funding the  Development  Program.  Except as  otherwise  set forth
below in this Section 3.6 Trinity  shall be solely  responsible  for funding all
the  costs  of  conducting  the  clinical  development  of  the  Product  in the
Territory, and the related activities necessary to obtain the required approvals
to market the Product in the Territory for use in the Field. IRC shall be solely
responsible  for  funding (a) the costs of  supplying  each  clinical  site with
certain  materials  as  identified  in the  applicable  protocol  for use in the
clinical  trial  to be  conducted  at  such  site,  and  (b)  its  internal  and
out-of-pocket costs of conducting its obligations under the Development Program.

         3.7 Development Reports and Results.

            3.7.1  Each  party  shall  keep the  other  informed  regarding  the
progress of such party's responsibilities  regarding the clinical development of
each Product and the preparing,  filing and obtaining of the required  approvals
to market the Product in the Territory for use in the Field.

            3.7.2 Within  thirty (30) days  following  the end of each  calendar
quarter  following the  commencement  of human clinical trials of the Product in
the Territory,  each party shall prepare, and provide to the other, a reasonably
detailed  written  report  which shall  describe  the  progress of such  party's
responsibilities  regarding the clinical development and testing of the Product,
all regulatory filings and submissions made, and all approvals obtained.

            3.7.3 Each party shall make its  employees  and relevant  reports of
nonemployee consultants available, upon reasonable notice during normal business
hours, at their respective  places of employment to consult with the other party
on issues  arising  during the  Development

                                      -7-
<PAGE>

Program and in connection with any request from any regulatory agency, including
regulatory, scientific, technical and clinical testing issues.

            3.7.4 Representatives of IRC and Trinity may, upon reasonable notice
during normal business hours, visit the facilities where the Development Program
is being conducted, and consult informally, during such visits and by telephone,
with personnel of the other party performing work on the Development Program. If
requested  by  the-other  party,   IRC  and  Trinity  shall  cause   appropriate
individuals  working on the Development  Program to be available for meetings at
the  location of the  facilities  where such  individuals  are employed at times
reasonably convenient to the party responding to such request.

            3.7.5 Trinity shall be the sole owner of all data,  information  and
other  results  (including,   without  limitation,  data  forms  and  protocols)
resulting  from or relating to the  clinical  trials of the  Product,  excluding
subject and patient  records.  IRC shall have the right to use and  disclose all
such data, information and results for any purpose.

         3.8  Election  Not to  Develop.  If  Trinity  elects at any time not to
develop and commercialize,  or abandons the development and commercialization of
the Product in any country in the Territory, then (a) all rights and obligations
of  Trinity to develop  and  commercialize  the  Product in such  country  shall
terminate,  and (b) thereafter IRC shall have the exclusive  right,  in its Sole
discretion and at its sole expense,  to develop and commercialize the Product in
such country.

         3.9 Excused  Performance.  In addition to the  provisions of Article 14
below,  the obligations of Trinity under the  Development  Program are expressly
conditioned upon the continuing  absence of any adverse  conditions  relating to
the safety or efficacy of the Product, and the obligations of Trinity to develop
the Product shall be delayed or suspended so long as any such condition or event
exists. If Trinity delays or suspends development of the Product in Thailand for
a period which exceeds  eighteen  (18) months in duration  (except for delays or
suspensions  due  solely  to  regulatory  delays  beyond  Trinity's   reasonable
control), then all Trinity's rights and obligations to develop and commercialize
the Product in the Territory  shall  terminate and thereafter IRC shall have the
exclusive right, in its sole discretion and at its sole expense,  to develop and
commercialize the Product in the Territory.

                                   ARTICLE 4

                      MANAGEMENT OF THE DEVELOPMENT PROGRAM
                      -------------------------------------

         4.1 Project  Leaders.  IRC and Trinity  each shall  appoint a person (a
"Project Leader") to coordinate its part of the Development Program. The Project
Leaders  shall be the primary  contacts  between the parties with respect to the
Development  Program.  Each party shall notify the other within thirty (30) days
of the date of the Agreement of the  appointment of its Project Leader and shall
notify the other party as soon as practicable upon changing this appointment.

         4.2 Disagreements.  All disagreements between the Project Leaders shall
be resolved in the following manner:

                                      -8-
<PAGE>

            4.2.1 The Project Leaders promptly shall present the disagreement to
the  executive of each of IRC and Trinity who has the  principal  responsibility
for such party's work under the Agreement.

            4.2.2 Such executives shall meet to discuss each party's view and to
explain  the basis for  their  respective  positions,  and in good  faith  shall
attempt to resolve such disagreement among themselves.

            4.2.3 If such executive  officers  cannot resolve such  disagreement
within thirty (30) days after the meeting described in Section 4.2.2 above, then
such  disagreements  shall be  resolved  in any  manner  which  such  executives
mutually agree or by any available legal or equitable means.

            4.2.4  Notwithstanding  the foregoing,  the parties do not waive any
rights  which they may have under the  Agreement or otherwise as a result of one
party's settlement of a disagreement under Section 4.2.3 above.

                                    ARTICLE 5

                                    LICENSES

         5.1 License Grant.  Except as otherwise provided in the Agreement,  IRC
hereby grants to Trinity an exclusive license in the Territory under the Product
Know-How  to  conduct  its  obligations  under the  Development  Program  in the
Territory and to sell,  distribute  and use the Product in the Territory for use
in the Field. Trinity shall not sell or distribute the Product in any country in
the Territory,  other than Thailand,  unless Trinity has previously received the
required  marketing approval from the governing health authority in Thailand for
the Product and Trinity has commenced marketing and is diligently  marketing the
Product in Thailand for use in the Field.

         5.2 Sublicense  Rights.  Trinity may not grant  sublicenses  under such
license to any  Affiliate or Third Party  without the prior  written  consent of
IRC,  except  for  sublicense  solely for the purpose of marketing,  promoting,
selling and distributing the Product. Trinity shall provide to IRC a copy of any
permitted  sublicense  promptly  upon  execution  of  the  same.  Any  permitted
sublicense shall be subject to the provisions of the Agreement.

         5.3  Reversion  of Rights to IRC.  With  respect to (a) each country in
which Trinity  abandons or elects not to develop or  commercialize  the Product,
and (b) the  Territory,  if Trinity  delays or suspends the  development  of the
Product in Thailand for more than eighteen (18) months under Section 3.10 above,
the  license  granted  to Trinity  with  respect  to each such  country  (or the
Territory under clause (b) above) shall automatically revert to IRC, and Trinity
shall have no further rights under the Agreement with respect thereto.

         5.4  Option  to  License  Manufacturing  Technology.   Subject  to  the
provisions of this Section 5.4, IRC shall have the  exclusive  right to make and
have made the Product for sale,  distribution  and use in the  Territory.  For a
period of three years commencing on the date of the First Commercial Sale of the
Product in  Thailand,  Trinity  shall  have the  exclusive  option,  in its sole
discretion, to obtain an exclusive license (except as to IRC and its Affiliates)
under the

                                      -9-
<PAGE>

Manufacturing  Know-How  to make  the  Product  in  Thailand  solely  for  sale,
distribution and use in the Territory. If Trinity gives timely written notice to
IRC of its exercise of such option, the parties promptly shall negotiate in good
faith and attempt to reach a mutually acceptable  agreement which would include,
without limitation,  the following material  provisions:  (a) grant of a license
(without  the right to  sublicense)  under the  Manufacturing  Know-How  to such
licensee  as the parties  mutually  agree  (which  shall be either  Trinity,  an
Affiliate of Trinity,  a joint  venture  entity  owned by IRC,  Trinity or their
respective  Affiliates,  or such other entity as the parties  mutually agree) to
make the  Product  in  Thailand  solely  for sale,  distribution  and use in the
Territory;  (b) transfer of the  Manufacturing  Know-How,  reasonable  technical
assistance  regarding  the  Manufacturing  Know-How and adequate  protection  to
prevent the unauthorized use or disclosure of the  Manufacturing  Know-How;  (c)
control of the  construction,  validation  and  licensing  of the  manufacturing
facility in accordance  with GMP and all applicable  laws,  regulations and good
manufacturing  practices  promulgated  by  the  governing  health  authority  of
Thailand;  (d) control of the  employees  and  operations  of the  manufacturing
facilities  and  processes;  (e) quality  control and quality  assurance  of the
Product in accordance  with GMP and all applicable  laws,  regulations  and good
manufacturing  practices  promulgated  by  the  governing  health  authority  of
Thailand;  (f) terms and conditions of a  manufacturing  royalty payable to IRC;
(g)  performance  criteria and maximum  output  limitations;  (h)  insurance and
indemnification provisions; (i) termination provisions; and (j) such other terms
and conditions as are customary or appropriate  in such  agreements.  If Trinity
fails to timely  give such  notice to IRC or, if after good faith  negotiations,
the parties  are unable to reach a mutually  acceptable  agreement  prior to the
expiration of such three-year period,  then Trinity shall have no further option
to obtain a license to make the Product in Thailand for sale,  distribution  and
use in the Territory.

         5.5 Right to Negotiate License to Gene Therapy  Products.  For a period
of  fifteen  (15)  years  after the date of the  Agreement,  Trinity  shall have
the-right, in its sole discretion,  to negotiate with IRC to obtain an exclusive
license  (except as to IRC and its  Affiliates)  in the  Territory  under  IRC's
patent rights and know-how, existing as of the date of the Agreement, to develop
and  commercialize  gene therapy products in the Territory for use in the Field.
If Trinity gives timely  written notice to IRC of its desire to so negotiate for
such a license, the parties shall negotiate in good faith and attempt to reach a
mutually  acceptable  agreement  which shall include,  without  limitation,  the
following  material  provisions:  (a) grant of a license  under the IRC's patent
rights and know-how to develop and  commercialize  such gene therapy products in
the  Territory  solely  for use in the  Field;  (b)  transfer  of any  necessary
technology to Trinity,  reasonable  technical assistance and adequate protection
to prevent the unauthorized  use or disclosure of such technology;  (c) research
and development  rights and  obligations;  (d) promotion,  marketing,  sales and
distribution  rights and obligations;  (e)  manufacturing  and supply rights and
obligations;   (f)  license  fee,  royalty  and  milestone   payment  terms  and
conditions;  (g) performance criteria and diligence  obligations;  (h) insurance
and indemnification  provisions;  (i) termination provisions; and (j) such other
terms and  conditions as are customary or  appropriate  in such  agreements.  If
Trinity  fails to  timely  give  such  notice  to IRC or,  if after  good  faith
negotiations,  the parties are unable to reach a mutually  acceptable  agreement
prior to the  expiration  of such fifteen (15) year period,  then Trinity  shall
have no  further  right  to  negotiate  to  obtain  a  license  to  develop  and
commercialize such gene therapy products in the Territory for use in the Field.

         5.6 Diligence.  Trinity  diligently  shall take all actions  reasonably
necessary to obtain the required  approval to market the Product in each country
in the Territory for use in the Field,

                                      -10-
<PAGE>

as  soon  as  commercially  practicable,   in  accordance  with  the  applicable
Development  Workplan and consistent  with prudent drug  development  practices.
Upon receipt of the required  marketing approval for the Product in a country in
the Territory, Trinity promptly shall commence marketing, and thereafter Trinity
diligently shall market the Product in such country for use in the Field to meet
the  reasonably  anticipated  market  demand for the  Product  in such  country.
Trinity shall not promote, market, sell, distribute,  seek customers,  establish
any branch or maintain any sales or distribution  network or instrumentality for
the sale or distribution of the Product outside the Territory.

                                   ARTICLE 6

                                 PRODUCT SUPPLY
                                 --------------

         6.1  Purchase  and Sale of  Products.  On the terms and  subject to the
conditions of the Agreement, IRC shall manufacture, sell and deliver the Product
to Trinity,  and Trinity shall purchase and accept such amount of the Product as
ordered by Trinity,  for sale,  distribution and use in the Territory for use in
the  Field.  The  Product  shall be  manufactured  to conform  with the  Product
Specifications and in compliance with the applicable laws and regulations of the
applicable governing health authority in the Territory.

            6.1.1 For  Clinical  Development.  IRC shall  manufacture,  sell and
deliver  to  Trinity  such  amounts  of the  Product  and  placebo,  as  Trinity
reasonably  requests,  equal to Trinity's  requirements of Products for clinical
development in the Territory under the Development Program.

            6.1.2 For Commercial Sale and Distribution.  IRC shall  manufacture,
sell and deliver to Trinity such amounts of the Product,  as Trinity  reasonably
requests  pursuant to the  provisions  of Section 6.4 below,  equal to Trinity's
requirements  of  the  Product  for  commercial  sale  and  distribution  in the
Territory for use in the Field.

         6.2 Packaging. Upon the mutual agreement of the parties in writing, IRC
shall supply Product under the Agreement in unlabeled unit dose containers.  The
specifications  of such unit dose  containers  shall  meet all  requirements  of
applicable  laws and  regulations.  If IRC supplies  Trinity with unlabeled unit
dose  containers of the Product,  Trinity,  at its sole expense,  shall finalize
packaging  and labeling of the Product for sale and  distribution  in accordance
with the requirements of applicable laws and regulations.

         6.3 Purchase Price and Payment Terms.

            6.3.1 Purchase Price.

            (a) With respect to clinical  development supply under Section 6.1.1
above, after receipt of approval from the governing health authority of Thailand
to conduct the applicable  human  clinical  trials in Thailand and approval from
the FDA to supply the Product for use  therein,  IRC shall  supply  Trinity with
such 100 microgram,  400 microgram and DTH skin testing doses of the Product and
placebo  (as set  forth  in  mutually  acceptable  protocols),  for use in human
clinical  trials in Thailand under the  Development  Program for a period not to
exceed  three  (3) years  after the  commencement  of human  clinical  trials in
Thailand.  IRC shall  supply  such

                                      -11-
<PAGE>

doses of Product and placebo for use in such human  clinical  trials in Thailand
for not more than  10,000  enrolled  patients  during  such period at no cost to
Trinity. If additional Product and placebo is required for use in human clinical
trials in Thailand  prior to the First  Commercial  Sale,  IRC shall supply such
additional Product and placebo as the parties mutually agree in writing;  at the
purchase price US$ *** per 100 microgram dose, US$*** per 400 microgram dose and
US$*** per DTH skin  testing dose of the Product and at such  purchase  price as
the parties mutually agree in writing for placebo.

            (b) With respect to clinical  development supply under Section 6.1.1
above,  for use in human  clinical  trials in any other Country in the Territory
under the Development  Program,  Trinity shall purchase such quantity of Product
and placebo from IRC at such price as the parties mutually agree in writing.

            (c) With respect to  commercial  supply under  Section  6.1.2 above,
Trinity shall purchase Product from IRC at a price determined as follows:  For a
period of three years  commencing  on the date of the First  Commercial  Sale in
Thailand,  the purchase price shall equal US$*** per 100 microgram dose,  US$***
per 400  microgram  dose and US$*** per DTH skin  testing  dose of the  Product;
provided,  however,  if the Product is  commercially  sold or distributed in the
Territory in other than 100 microgram, 400 microgram and DTH skin testing doses,
or if IRC's  Manufacturing Cost materially  increases prior to the expiration of
such  three-year  period,  then the  parties  shall  negotiate  in good  faith a
mutually  acceptable  adjustment  to the purchase  price for the balance of such
period which  enables IRC,  considering  all the  circumstances,  to receive the
substantially equivalent economic benefit from the adjusted purchase price as it
reasonably expected as of the date of the Agreement to receive from the purchase
price set forth above.  After the three-year  period as aforesaid,  the purchase
price shall be revised  annually,  on or before each  anniversary of the date of
the First  Commercial  Sale of the Product in  Thailand,  by the mutual  written
agreement of the parties.

            (d) IRC shall  calculate its  Manufacturing  Cost for the Product in
good faith in a manner which  reasonably  and  equitably  allocates  the cost of
overhead,  materials,  direct labor and benefits (each as defined in Section 1.9
above) to the Product.

            6.3.2 Invoicing. ***

            6.3.3 Sales and Use Taxes. Any federal,  state,  county or municipal
sales or use tax,  excise or  similar  charge,  or other tax  assessment  of any
country (other than that assessed  against  income),  assessed or charged on the
sale of Product sold pursuant to the Agreement shall be paid by Trinity.

         6.4 Orders and Forecasts.

            6.4.1 Prior to Regulatory  Approval.  Beginning upon Trinity's first
submission  for  regulatory  approval  of the  Product to the  governing  health
authority  in  Thailand,  and prior to  approval  to market  the  Product by the
governing  health  authority  in  Thailand,  Trinity  shall  issue at  quarterly
intervals a twelve (12) month forecast estimating Trinity's requirements of such
Product for the first twelve (12) months of supply.  These forecasts may be used
by IRC for planning  purposes only, unless and until such time as Trinity elects
to issue an order or  purchase

                                      -12-
<PAGE>

order for its first delivery of Product in anticipation of Product approval. The
order or purchase  order (as the case may be) shall  indicate dates and delivery
information  requirements.  Trinity shall be obligated to accept or purchase and
IRC shall supply one hundred percent (100%) of the quantity of Product listed in
this initial  order or purchase  order (as the case may be)  provided  that such
order or  purchase  order (as the case may be) is  received by IRC not less than
six (6) months prior to the  requested  delivery  date in such order or purchase
order (as the case may be).  If such  order or  purchase  order (as the case may
be)  contains a  delivery  date of less than six (6)  months,  IRC shall use its
commercially reasonable efforts to meet such delivery date.

            6.4.2 After Regulatory  Approval.  Subsequent to regulatory approval
to market the Product in Thailand,  Trinity shall continue to issue at quarterly
intervals  a twelve  (12) month  forecast  estimating  its  requirements  of the
Product during the succeeding four quarterly periods.  Trinity shall be required
to accept or purchase  one  hundred  percent  (100%) of the  quantity of Product
listed for the first quarterly period of each forecast and seventy-five  percent
(75%) of the quantity of Product listed for the second  quarterly period of such
forecast, but shall be able to increase or decrease the quantities estimated for
the remaining two quarters of such  forecast in  subsequent  forecasts.  Trinity
shall  issue  orders or  purchase  orders  (as the case may be) for its  Product
requirements which shall provide dates and delivery information requirements.

            6.4.3 Supply Obligation. IRC shall supply one hundred percent (100%)
of Product listed for the first  quarterly  period of each  forecast,  and shall
have sufficient  in-process inventory to produce one hundred twenty-five percent
(125%) of the quantity of Product listed for the second quarterly period of each
forecast. IRC shall use its commercially  reasonable best efforts to accommodate
any  increases in quantity of Product  which  Trinity  shall  request  under new
orders  or  purchase  orders  (as the case may be).  IRC  shall  meet  Trinity's
delivery  requirements  specified in  accordance  with this  Section 6.4.  IRC's
obligation to supply Product, after regulatory approval to market the Product in
Thailand,  shall be subject to  consummation  of the  purchase by Trinity of the
shares of IRC common stock required to be purchased pursuant to Section 1.1.2 of
the Stock Purchase Agreement.

            6.4.4  Planning  Forecasts.  Each  September  during the term of the
Agreement or any  extension  thereof,  Trinity  shall  prepare for IRC a special
planning  forecast  for  the  following   calendar  year  estimating   Trinity's
requirements  for each Product for such year. This forecast shall not be binding
upon the parties and shall be used for internal planning purposes only.

            6.4.5  Agreement  Controlling.  Each firm order by Trinity under the
Agreement shall be governed by the terms of the Agreement.  None of the terms or
conditions of Trinity's or IRC's orders,  purchase  orders,  invoices or similar
instruments  shall be  applicable,  except those  specifying  quantity  ordered,
delivery dates, special supply instructions and invoice information.

         6.5 Manufacturing Practices.

            6.5.1 GMP.  IRC shall  manufacture  Product  under the  Agreement in
accordance  with GMP, IRC shall promptly  advise Trinity of any process  changes
experienced  by IRC during the  manufacture  of Product.  Trinity shall have the
right,  at its sole expense,  to audit IRC for compliance with GMP at reasonable
intervals.  Such audits shall be scheduled at mutually  agreeable  times upon at
least fifteen (15) days' prior written notice to IRC.

                                      -13-
<PAGE>

            6.5.2  Certificates of Analysis.  IRC shall provide  certificates of
analysis to Trinity for all Product delivered hereunder.

            6.5.3 Quality Control  Information.  Upon the reasonable  request of
either IRC or Trinity,  the other party shall provide the requesting  party with
such  information,   including   analytical  and  manufacturing   documentation,
requested by the requesting  party  relating to quality  control of the Product;
provided,  however,  the  requesting  party  shall  treat  all such  information
disclosed pursuant to this Section 6.5.3 as confidential  information subject to
the provisions of Article 10 below.

         6.6 Delivery and Acceptance.

            6.6.1  Delivery.  IRC's  obligation  to deliver  Products  under the
Agreement  shall be subject to obtaining all necessary  consents,  approvals and
authorizations of the applicable  governmental and regulatory  authorities.  All
Products  supplied  under  the  Agreement  shall  be  shipped  f.o.b.  place  of
manufacture.  Title and risk of loss and damages to the  Products  shall pass to
Trinity upon release to Trinity's designated carrier.

            6.6.2  Rejection  and Cure.  If a shipment of Product or any portion
thereof is spoiled,  damaged or defective,  then Trinity shall have the right to
reject such  shipment of the  Product or the  portion  thereof  that fails to so
conform,  as the case may be.  Trinity  shall give written  notice to IRC of its
rejection  hereunder,  within sixty (60) days  following  the date on which such
shipment was delivered,  specifying the grounds for such  rejection.  All or any
part of any shipment may be held for IRC's  disposition  and at IRC's expense if
found to be not in conformance with the Product  Specifications.  No claims with
respect to rejected  Product  shall be in an amount  greater  than the  purchase
price of such Product;  provided,  however,  that IRC shall use its commercially
reasonable  efforts to cure such  rejection or replace such spoiled,  damaged or
defective  shipment of Product within  ninety (90) days after receipt of notice
of rejection thereof. Should cover be utilized, IRC shall be responsible for the
cost of such cover pertaining to the rejected Product in question.  If no notice
of rejection is given by Trinity within such sixty (60) day period, the shipment
of the Product shall be deemed to have been accepted.

         6.7  Subcontract  Manufacture.  IRC shall have the right to subcontract
with an Affiliate or Third Party subcontractor to manufacture,  sell and deliver
Products under the Agreement.

                                    ARTICLE 7

                                    ROYALTIES
                                    ---------

            During the Royalty Term, Trinity shall pay to IRC royalties equal to
US$*** per each 100 microgram dose, US$*** per 400 microgram dose and US$*** per
DTH skin  testing  dose of the  Product  sold or  distributed  by  Trinity,  its
Affiliates and sublicensees in the Territory.  Notwithstanding the foregoing, if
the Product is sold or  distributed  and used in the Territory in other than 100
microgram, 400 microgram and DTH skin testing doses, the parties shall negotiate
a  mutually  acceptable  adjustment  to the  royalty  rate  which  enables  IRC,
considering all the circumstances, to receive the substantially equivalent

                                      -14-
<PAGE>

economic benefit from the adjusted royalty rate as it reasonably  expected as of
the date of the Agreement to receive from the royalty rate set forth above.

                                   ARTICLE 8

                         ROYALTY REPORTS AND ACCOUNTING
                         ------------------------------

         8.1 Reports, Exchange Rates. During the term of the Agreement following
the  First  Commercial  Sale of the  Product,  Trinity  shall  furnish  to IRC a
quarterly written report showing in reasonably  specific detail, on a country by
country basis,  (a) the quantity of all Product sold or distributed by Trinity,
its  Affiliates  and its  sublicensees  in the  Territory  during the  reporting
period;  (b) the calculation of royalties  payable in United States dollars,  if
any, which shall have accrued based upon such sale or  distribution  of Product;
(c) the withholding  taxes, if any, required by law with respect to such sale or
distribution;  and (d) the date of the First  Commercial  Sale of the Product in
each country in the Territory during the reporting period.  Reports shall be due
on the thirtieth  (30th) day following the close of each quarter.  Trinity shall
keep complete and accurate records in sufficient  detail to properly reflect all
sales and  distributions  of the  Product  and to enable the  royalties  payable
hereunder to be determined.

         8.2 Audits.


            8.2.1  Upon the  written  request  of IRC and not more than twice in
each  calendar  year,  Trinity  shall  permit an  independent  certified  public
accounting  firm of  internationally  recognized  standing,  selected by IRC and
reasonably acceptable to Trinity, at IRC's expense, to have access during normal
business hours to such of the records of Trinity as may be reasonably  necessary
to verify the accuracy of the royalty reports  hereunder for any year ending not
more  than  thirty-six  (36)  months  prior  to the  date of such  request.  The
accounting  firm shall  disclose to IRC only  whether the records are correct or
not and the specific details concerning any discrepancies.  No other information
shall be shared.

            8.2.2 If such accounting  firm concludes that  additional  royalties
were owed during such period,  Trinity shall pay the additional royalties within
thirty (30) days of the date IRC  delivers  to Trinity  such  accounting  firm's
written report so concluding.  The fees charged by such accounting firm shall be
paid by IRC;  provided,  however,  if the  audit  discloses  that the  royalties
payable by Trinity for the audited period are more than one hundred five percent
(105%) of the royalties  actually  paid for such period,  then Trinity shall pay
the reasonable fees and expenses charged by such accounting firm.

            8.2.3 Trinity shall include in each permitted  sublicense granted by
it pursuant  to the  Agreement a provision  requiring  the  sublicensee  to make
reports to Trinity, to keep and maintain records of sales and distributions made
pursuant  to such  sublicense  and to  grant  access  to such  records  by IRC's
independent  accountant  to the  same  extent  required  of  Trinity  under  the
Agreement.  Upon the expiration of thirty-six  (36) months  following the end of
any year, the  calculation of royalties  payable with respect to such year shall
be binding  and  conclusive  upon IRC and  Trinity  shall be  released  from any
liability or accountability with respect to royalties for such year.

                                      -15-
<PAGE>

         8.3 Confidential Financial  Information.  IRC shall treat all financial
information  subject  to review  under  this  Article 8 or under any  sublicense
agreement as  confidential,  and shall cause its  accounting  firm to retain all
such financial information in confidence.

                                    ARTICLE 9

                                    PAYMENTS
                                    --------

         9.1 Payment  Terms.  Royalties  shown to have  accrued by each  royalty
report  provided for under  Article 8 above shall be due and payable on the date
such royalty report is due. Payment of royalties in whole or in part may be made
in advance of such due date.

         9.2 Payment Method.  All payments by Trinity to IRC under the Agreement
shall  be paid  in  United  States  dollars,  and all  such  payments  shall  be
originated  from a United  States bank located in the United  States and made by
bank wire transfer in immediately  available  funds,  or by such other method of
payment as IRC and Trinity mutually agree in writing before such payment is due,
to such account as IRC shall designate before such payment is due.

         9.3 Exchange  Control.  If at any time legal  restrictions  prevent the
prompt  remittance of part or all  royalties  with respect to any country in the
Territory  where  the  Product  is sold or  distributed,  payment  shall be made
through such lawful means or methods as IRC reasonably shall determine.

         9.4 Withholding  Taxes. All amounts owing from Trinity to IRC under the
Agreement  are  net  amounts,  and  shall  be  grossed-up  to  account  for  any
withholding  taxes,  value-added  taxes or other  taxes,  levies or charges with
respect  to such  amounts,  other  than (a)  United  States  taxes and (b) taxes
imposed  solely by reason of IRC having a permanent  establishment  in any other
country or IRC  otherwise  being  subject to  taxation by such  country  (except
solely by reason of the license granted under the Agreement).

         9.5 Late Payments. Unless otherwise provided in the Agreement,  Trinity
shall pay  interest to IRC on the  aggregate  amount of any  payments by Trinity
that  are not paid on or  before  the  date  such  payments  are due  under  the
Agreement at a rate per annum equal to the prime rate of interest as reported by
Bank of America  NT&SA in San  Francisco,  California,  from time to time,  plus
***, calculated on the number of days such payment is delinquent.

                                   ARTICLE 10

                                 CONFIDENTIALITY
                                 ---------------

         10.1  Nondisclosure  Obligations.  Except as otherwise provided in this
Article 10,  during the term of the Agreement and for a period of five (5) years
thereafter,  Trinity shall  maintain in confidence  and use only for purposes of
the Agreement all information and data, of any type whatsoever, (a) disclosed by
IRC and identified as, or  acknowledged  to be,  confidential,  or (b) resulting
from the  Development  Program or  relating to the  Product  (the  "Confidential
Information").

                                      -16-
<PAGE>

         10.2 Permitted Disclosures. To the extent it is reasonably necessary or
appropriate to fulfill its obligations under the Agreement, Trinity may disclose
(a) Confidential Information it is otherwise obligated under this Article 10 not
to disclose to its employees on a need-to-know  basis on the condition that such
persons agree in writing,  or are subject to a written  Institution  policy,  to
keep the Confidential  Information confidential for the same time periods and to
the same  extent as Trinity is  required  to keep the  Confidential  Information
confidential  and (b) such  Confidential  Information to  governmental  or other
regulatory  authorities  to the  extent  that such  disclosure  is  required  by
applicable  law,  regulation  or court order,  provided  that Trinity shall give
advance  written notice to IRC thereof and  sufficient  opportunity to object to
such  disclosure or to request  confidential  treatment  thereof.  Trinity shall
notify IRC promptly upon discovery of any  unauthorized use or disclosure of the
Confidential Information.

         The obligation not to disclose or use  Confidential  Information  shall
not apply to the extent that  Trinity  can  demonstrate  that (i) the  disclosed
information was public  knowledge at the time of such disclosure by Trinity,  or
thereafter  became  public  knowledge,  other  than as a result  of  actions  of
Trinity,  its directors,  officers or employees,  in violation hereof;  (ii) the
disclosed  information  was  rightfully  known by Trinity or its  affiliates (as
shown  by its  written  records)  prior  to the date of  disclosure  to  Trinity
hereunder:  or (iii) the disclosed  information  was disclosed to Trinity or its
affiliates on an unrestricted  basis from a source unrelated to any party to the
Agreement and not under a duty of confidentiality to IRC.

         10.3  Publication.  Subject to the provisions of Sections 10.1 and 10.2
above,  Trinity  shall have the right to publish the results of the  Development
Program;  provided,  however,  that Trinity shall provide IRC the opportunity to
review any proposed manuscripts or any other proposed disclosure  describing the
such  results not less than sixty (60) days prior to their  proposed  submission
for  publication  or other  proposed  disclosure.  IRC  shall  have the right to
require the delay of any such  publication  or disclosure  for a period of up to
ninety (90) days to permit IRC to prepare and file such patent  applications  as
it believes are necessary or desirable to protect any patentable  subject matter
to be disclosed in such publication or other disclosure. IRC shall also have the
right to require the delay of any such publication or disclosure until such time
as IRC has filed such results with the FDA.

         10.4 Terms of the  Agreement.  IRC and Trinity  shall not  disclose any
terms or  conditions  of the  Agreement  to any Third  Party  without  the prior
consent of the other party,  except as required by applicable  law or to Persons
with whom  Trinity or IRC has entered  into or proposes to enter into a business
relationship,   provided  that  such  Persons  shall  enter  into  the  regutied
confidentiality agreement.  Notwithstanding the foregoing, prior to execution of
the  Agreement,  Trinity and IRC shall agree upon the  substance of  information
that can be used to describe the terms of this transaction,  and Trinity and IRC
may disclose  such  information,  as modified by mutual  agreement  from time to
time, without the other party's consent.

                                   ARTICLE 11

                              TERM AND TERMINATION
                              --------------------

                                      -17-
<PAGE>

         11.1 Expiration. Unless terminated earlier pursuant to Sections 11.2 or
11.3  below,   the  Agreement  shall  expire  on  the  expiration  of  Trinity's
obligations to pay royalties under the Agreement.

         11.2 Termination by IRC. The Agreement shall  terminate,  at the option
of IRC  effective  upon written  notice  thereof to Trinity,  if Trinity has not
received the required  marketing approval from the governing health authority of
Thailand  for the  Product on or before the first to occur of (a) the date which
is eighteen  (18) months after receipt of the required  marketing  approval from
the FDA for the Product in the United States,  (b) the date which is twenty-four
(24) months  after  completion  of the Phase 3 clinical  trial of the Product in
Thailand under the applicable Development Workplan, and (c) December 31, 2000.

         11.3  Termination  for Cause.  Either party may terminate the Agreement
upon the occurrence of any of the following:

            11.3.1 Trinity shall have failed to timely deliver to IRC the letter
of credit required under Section 1.4 of the Stock Purchase Agreement; or

            11.3.2  Trinity has not  received,  on or before April 1, 1996,  the
required  approval from the governing  health  authority of Thailand to commence
human  clinical   trials  of  the  Product  in  Thailand  under  the  applicable
Development Workplan; or

            11.3.3  Trinity  shall  have  failed to  purchase  the shares of IRC
common stock under  Section 1.1.1 and/or 1.1.2 of the Stock  Purchase  Agreement
(without regard to Section 1.2 of the Stock Purchase Agreement); or

            11.3.4 Any serious and unexpected side effect,  injury,  toxicity or
sensitivity  reaction,  or any unexpected incidence associated with the clinical
uses,  studies,  investigations,  tests and marketing of the Product, as further
specified in Article 13 below; or

            11.3.5   The   other   party   shall   (a)  seek  the   liquidation,
reorganization,  dissolution or winding up of itself (other than  dissolution or
winding  up  for  the  purposes  of   reconstruction  or  amalgamation)  or  the
composition or readjustment of all or substantially  all of its debts, (b) apply
for or  consent  to the  appointment  of,  or the  taking  of  possession  by, a
receiver,  custodian, trustee or liquidator of itself or of all or substantially
all of its  assets,  (c)  make a  general  assignment  for  the  benefit  of its
creditors,  (d) commence a voluntary case under the Bankruptcy  Code, (e) file a
petition  seeking to take  advantage  of any other law  relating to  bankruptcy,
insolvency, reorganization,  winding-up or composition or readjustment of debts,
or (f) adopt any  resolution of its Board of Directors or  stockholders  for the
purpose of effecting any of the foregoing; or

            11.3.6  A  proceeding  or  case  shall  be  commenced   without  the
application  or consent  of the other  party and such  proceeding  or case shall
continue undismissed,  or an order, judgment or decree approving or ordering any
of the following shall be entered and continue unstayed in effect,  for a period
of ninety (90) days from and after the date service of process is effected  upon
the other party,  seeking (a) its  liquidation,  reorganization,  dissolution or
winding up, or the composition or readjustment  of all or  substantially  all of
its debts, (b) the appointment of a trustee, receiver, custodian,  liquidator or
the like of itself or of all or substantially all of its

                                      -18-
<PAGE>

assets, or (c) similar relief under any law relating to bankruptcy,  insolvency,
reorganization, winding up or composition or readjustment of debts; or

            11.3.7  Upon or after the breach of any  material  provision  of the
Agreement or any material  provision  (other than Sections 1.1.1 and 1.4) of the
Stock  Purchase  Agreement,  if the  breaching  party has not cured such  breach
within  ninety (90) days,  or such longer  period as the other party in its sole
discretion  agrees,  after notice  thereof from the other party,  the  Agreement
shall terminate,  at the option of the other party,  upon the expiration of such
cure period.

         11.4 Effect of Expiration and Termination. Expiration or termination of
the Agreement shall not relieve the parties of any obligation  accruing prior to
such  expiration  or  termination.  The  provisions  of Articles 10 and 12 shall
survive the expiration or termination of the Agreement.

                                    ARTICLE 12

                                    INDEMNITY
                                    ---------

         12.1 Direct Indemnity. Each party shall indemnify,  defend and hold the
other party  harmless,  and hereby  forever  releases and  discharges  the other
party,  from  and  against  any  loss,  liability,  cost or  expense,  including
attorneys' fees and costs (any "Liability"), resulting from any claim, action or
other proceeding by a Third Party,  arising out of the negligence,  recklessness
or intentional  acts or omissions of the  indemnifying  party in connection with
the work performed by such party during the Development Program.

         12.2 Other Indemnity.  Each party shall indemnify,  defend and hold the
other party harmless from and against any  Liability,  resulting from any claim,
action or other  proceeding  by a Third  Party,  for  personal  injuries  or any
product  recall to the extent  caused by:  (a) any  failure of the  indemnifying
party to test for or provide  adequate  warnings of adverse  side effects to the
extent such  failure  arises out of acts or omissions  in  connection  with such
party's obligations hereunder,  (b) any manufacturing defect by the indemnifying
party in the Product or any other material  manufactured  by such party,  or (c)
any  other  act  or  omission  (without  regard  to  culpable  conduct)  of  the
indemnifying  party in connection  with the  activities  contemplated  under the
Agreement;  except in each case to the extent any such  Liability  resulted from
negligence, recklessness or intentional acts or omissions of the other party.

         12.3  Procedure.  A party  (the  "Indemnitee")  that  intends  to claim
indemnification  under  this  Article  12 shall  promptly  notify the Party (the
"Indemnitor") under obligation of indemnification hereunder of any Liability for
which the Indemnitee intends to claim such indemnification. The Indemnitor shall
have the right to participate  in, and, to the extent the Indemnitor so desires,
jointly  with any other  indemnitor  similarly  noticed,  to assume the  defense
thereof with counsel  selected by the  Indemnitor;  provided,  however,  that an
Indemnitee  shall  have the right to retain its own  counsel,  with the fees and
expenses to be paid by the Indemnitee,  if representation of such Indemnitee by,
the counsel retained by the Indemnitor  would be inappropriate  due to actual or
potential  differing  interests  between  such  Indemnitee  and any other  party
represented by such counsel in such proceedings. The indemnity agreement in this
Article

                                      -19-
<PAGE>

12 shall not apply to amounts paid in settlement  if effected  without the prior
express  written  consent  of  the  Indemnitor,   which  consent  shall  not  be
unreasonably  withheld  or  delayed.  The  failure  to  deliver  notice  to  the
Indemnitor  within a reasonable time after the  commencement of any such action,
if  prejudicial  to its  ability  to  defend  such  action,  shall  relieve  the
Indemnitor  of any  liability to the  Indemnitee  under this Article 12, but the
omission  so to  deliver  notice to the  Indemnitor  will not  relieve it of any
liability that it may have to the  Indemnitee  otherwise than under this Article
12. The Indemnitor may not settle the action or otherwise  consent to an adverse
judgment  in  such  action  that  diminishes  the  rights  or  interests  of the
Indemnitee   without  the  express  written  consent  of  the  Indemnitee.   The
Indemnitee,  its employees and agents, shall cooperate fully with the Indemnitor
and its legal  representatives in the investigation and defense of any Liability
covered by this indemnification.

         12.4  Insurance.  Trinity  and IRC each shall  maintain,  through  self
insurance or otherwise, product liability insurance with respect to development,
manufacture, sale and distribution of the Product by Trinity or IRC, as the case
may be, in such amount as Trinity or IRC,  respectively,  customarily  maintains
with respect to sales and  distribution of its other products.  Trinity and IRC,
as  applicable,  shall  maintain such insurance for so long as each continues to
manufacture,  sell or  distribute  the Product,  and  thereafter  for so long as
Trinity and IRC, as applicable, each maintain insurance for itself covering such
manufacture, or sale distribution.

                                   ARTICLE 13

                          ADVERSE EXPERIENCE REPORTING
                          ----------------------------

         During the term of the  Agreement,  each party  shall  notify the other
immediately of any information concerning any serious or unexpected side effect,
injury,  toxicity or sensitivity reaction, or any unexpected incidence,  and the
severity thereof,  associated with the clinical uses,  studies,  investigations,
tests and marketing of the Product.  For purposes of this Article 13,  "serious"
shall  mean  an  experience  which  (a)  results  in  the  death,  permanent  or
substantial   disability,   in-patient   hospitalization   or   prolongation  of
hospitalization,  or (b) is a  congenital  anomaly,  cancer,  the  result  of an
overdose or life  threatening.  For  purposes of this  Article 13,  "unexpected"
shall mean (x) for a non-marketed  product, an experience that is not identified
in  nature,  severity  or  frequency  in  the  current  clinical  investigator's
confidential information brochure, and (y) for a marketed product, an experience
which is not listed in the current  labeling for such  product,  and includes an
event that may be symptomatically and  pathophysiologically  related to an event
listed in the labeling but differs from the event because of increased frequency
or greater severity or specificity.  Each party further shall immediately notify
the other of any information received regarding any threatened or pending action
by an agency  which may  affect  the  safety  and  efficacy  claims of any such
product.  Upon receipt of any such  information,  the parties shall consult with
each other in an effort to arrive at a mutually acceptable  procedure for taking
appropriate action;  provided,  however,  that nothing contained herein shall be
construed as  restricting  either  party's right to make a timely report of such
matter  to any  government  agency  or take  other  action  that it  deems to be
appropriate or required by applicable law or regulation.

                                      -20-
<PAGE>

                                   ARTICLE 14

                                  FORCE MAJEURE
                                  -------------

         Neither  party shall be held liable or  responsible  to the other party
nor be deemed to have  defaulted  under or breached the Agreement for failure or
delay in fulfilling or performing  any term of the Agreement to the extent,  and
for SO long as, such failure or delay is caused by or results from causes beyond
the reasonable  control of the affected party including but not limited to fire,
floods,  embargoes,  war,  acts  of  war  (whether  war  be  declared  or  not),
insurrections,  riots,  civil  commotions,  strikes,  lockouts  or  other  labor
disturbances,  acts  of God or  acts,  omissions  or  delays  in  acting  by any
governmental authority or the other party.

                                   ARTICLE 15

                                   ASSIGNMENT
                                   ----------

         The Agreement may not be assigned nor, except as expressly  provided or
otherwise  transferred,  hereunder,  may any right or  obligations  hereunder be
assigned or  transferred by either party without the consent of the other party;
provided, however, that either IRC or Trinity may, without sue Agreement and its
rights and  obligations  hereunder  connection with the transfer or sale of all
or  substantially  all of  its  business,  or in the  event  of  its  merger  or
consolidation  or  change in  control  or  similar  transaction.  Any  permitted
assignee shall assume all obligations of its assignor under the Agreement.

                                   ARTICLE 16

                                  SEVERABILITY
                                  ------------

         Each party hereby  acknowledges  that it does not intend to violate any
public policy, statutory or common laws, rules, regulations,  treaty or decision
of any  government  agency or executive body thereof of any country or community
or association of countries.  Should one or more  provisions of the Agreement be
or become  invalid,  the parties  shall  substitute,  by mutual  consent,  valid
provisions for such invalid  provisions which valid provisions in their economic
effect  are  sufficiently  similar  to the  invalid  provisions  that  it can be
reasonably  assumed that the parties would have entered into the Agreement  with
such provisions. In case such provisions cannot be agreed upon the invalidity of
one or several  provisions of the Agreement shall not affect the validity of the
Agreement  as a whole,  unless  the  invalid  provisions  are of such  essential
importance to the Agreement that it is to be reasonably assumed that the parties
would not have entered into the Agreement without the invalid provisions.

                                   ARTICLE 17

                                  MISCELLANEOUS
                                  -------------

         17.1 Notices. Any consent, notice or report required or permitted to be
given or made under the  Agreement  by a party to the other shall be in writing,
delivered  personally  or by  facsimile  (and  promptly  confirmed  by  personal
delivery,   air  mail  or   internationally-recognized
                                      -21-

<PAGE>

courier), air mail,  internationally-recognized  courier, postage prepaid (where
applicable),  addressed to the other party at its address indicated below, or to
such other address as the addressee, shall have last furnished in writing to the
addressor and (except as otherwise provided in the Agreement) shall be effective
upon receipt by the addressee.

         If to IRC:              The Immune Response Corporation
                                 5935 Darwin Court
                                 Carlsbad, California 92008, U.S.A.
                                 Attention: Dennis J. Carlo, Ph. D.

         with a copy to:         Pillsbury Madison & Sutro
                                 235 Montgomery Street, 15th Floor
                                 San Francisco, California 94104, U.S.A.
                                 Attention: Thomas E. Sparks, Jr.

                                 If to Trinity: Trinity Medical Group, Co., Ltd.
                                 425/5 Silom No. 7
                                 Silom Road
                                 Bangkok 10900, Thailand
                                 Attention: Mr. Arun Churdboonchart

         17.2  Applicable  Law. The Agreement shall be governed by and construed
in accordance  with the laws of the State of  California,  without regard to the
conflicts  of law  principles  thereof,  and shall not be governed by the United
Nations Convention on Contracts for the International Sale of Goods.

         17.3 U. S. Export Laws and Regulations.  Each party  acknowledges  that
its rights  and  obligations  under the  Agreement  are  subject to the laws and
regulations  of the  United  States  relating  to the  export  of  products  and
technical information. Without limitation, each party shall comply with all such
laws and regulations.

         17.4 Legal Enforcement.  If a party initiates any legal action or other
proceeding for the enforcement or interpretation of the Agreement, or because of
a dispute or an alleged default,  breach or misrepresentation in connection with
the Agreement or the rights or obligations of the parties hereunder, the parties
consent to the  exclusive  personal  jurisdiction  of the  appropriate  state or
federal court located in San Francisco,  California,  U.S.A.,  in such action or
other proceeding.

         17.5 Entire Agreement.  The Agreement and the Stock Purchase  Agreement
dated as of the  date  hereof  between  IRC and  Trinity,  together  with  their
respective  exhibits,  contain  the entire  understanding  of the  parties  with
respect to the subject  matter  hereof.  All express or implied  agreements  and
understandings, either oral or written, heretofore made are expressly superseded
by the  Agreement.  The Agreement may be amended,  or any term hereof  modified,
only by a written instrument duly executed by both parties.

                                      -22-
<PAGE>

         17.6 Headings. The captions to the several Articles and Sections hereto
are not a part of the  Agreement,  but are merely  guides or labels to assist in
locating and reading the several Articles and Sections hereof.

         17.7  Independent  Contractors.  It is  expressly  agreed  that IRC and
Trinity shall be independent  contractors and that the relationship  between the
two parties shall not constitute a partnership, joint venture or agency. Neither
IRC nor Trinity shall have the authority to make any statements, representations
or commitments of any kind, or to take any action, which shall be binding on the
other, without the prior consent of the party to do so.

         17.8  Waiver.  The  waiver by either  party of any right  hereunder  or
failure  to  perform  or of a breach  by the other  party  shall not be deemed a
waiver of any other right  hereunder  or of any other  breach or failure by said
other party whether of a similar nature or otherwise.

         17.9  Counterparts.  The  Agreement  may be  executed  in  two or  more
counterparts, each of  which  shall  be  deemed  an  original,  but all of which
together shall constitute one and the same instrument.

                                      -23-

<PAGE>


         IN WITNESS  WHEREOF,  the parties have executed the Agreement as of the
date first set forth above.

                                                THE IMMUNE RESPONSE CORPORATION


                                                By:  /s/ Dennis J. Carlo, Ph. D.
                                                  ------------------------------
                                                 Title President and CEO
                                                  ------------------------------


                                                TRINITY MEDICAL GROUP, CO., LTD.

                                                 By:   /s/  Arun Churdboonchart
                                                    ----------------------------
                                                 Title:   President and CEO
                                                       -------------------------

                                      -24-
<PAGE>

                                    Exhibit A

                       DEVELOPMENT WORK PLAN FOR THAILAND

A.       ACTIVITIES  NECESSARY  TO OBTAIN  ALL  APPLICABLE  MARKETING  APPROVALS
         REQUIRED FOR THE COMMERCIAL SALE,  DISTRIBUTION,  OR USE OF THE PRODUCT
         IN THAILAND.

         1.     Clinical trial as required by the Thai Government;
         2.     Apply with the Thai FDA for permission to import product;
         3.     Register with the Ministry of Commerce;
         4.     Acquire license for commercialization.

B.       THE GENERAL  STRUCTURE OF ALL HUMAN CLINICAL  TRIALS TO BE CONDUCTED IN
         THAILAND.

         A Phase II (Protocol No. 2101 June 23, 1995), randomized, double blind,
         two arm, placebo  controlled safety and  immunogenicity  study in up to
         300 HIV infected  subjects with CD4 counts greater than or equal to 300
         cells/ul.

         A Phase III (Protocol No. 301 June 23, 1995) randomized,  double-blind,
         multicenter,  two arm, placebo  controlled  clinical  endpoint study in
         2,000 HIV seropositive  patients.  An additional 7,700 HIV seropositive
         patients  may be enrolled in an open label  clinical  study upon mutual
         agreement of the parties.

C.       PRINCIPAL INVESTIGATORS (CO-CHAIRS) FOR THE HUMAN CLINICAL TRIALS.

         Protocol Coordinator:              Dr. Vina Churdboonchart, Ph. D.
         Protocol Co-Chairs :               Anuwat Limsuwan, MD
                                            Chuanchom Sakondhavat, MD
                                            Buranaj Smutharaks, MD, Msc, Mph
                                            Ronald B. Moss, MD

         Scientific Advisor :               Pradit Chareonthaitawee, MD

D.       THE  REQUIRED  RESOURCES  AND EFFORTS OF IRC AND TRINITY  NECESSARY  TO
         CONDUCT  THE  CLINICAL  TRIALS  AND TO OBTAIN  THE  REQUIRED  MARKETING
         APPROVAL IN THAILAND.

         RESPONSIBILITIES OF THE IMMUNE RESPONSE CORPORATION

         1.       Supply product for clinical trial use.
         2.       Draft protocol,  statistical  analysis plan, case report forms
                  and informed consent form.
         3.       Organize  the  data   management   system  (Case  Report  Form
                  tracking,  database  setup,  data entry,  QA review,  database
                  closure,  and  statistical  analysis) in conjunction  with the
                  contract  research  organization  (CRO)  or a Thai  Government
                  approved committee and PI.
         4.       Assist  with   preparation  of  the  medical  and  statistical
                  summaries  in  conjunction  with the CRO or a Thai  Government
                  approved committee and PI.
<PAGE>

         5.       Set up the clinical supplies  labeling,  ordering and tracking
                  system  in  conduction  with  the  CRO  or a  Thai  Government
                  approved committee and PI.
         6.       Organization  of a Data Safety and Efficacy  Monitoring  Board
                  (DSMB) composed of HIV clinical and statistical  experts to be
                  administered  by  the  CRO  or  a  Thai  Government   approved
                  committee and PI.
         7.       Draft   development   of  all  study   preparation   materials
                  (instructions manuals, monitoring notebook, Q&A line, etc.) in
                  conjunction  with  the  CRO  or  a  Thai  Government  approved
                  committee and PI.
         8.       Preparation of regulatory submissions for exporting of Product
                  to Thailand and to assist with  regulatory  submissions to the
                  Thailand FDA.
         9.       Assistance with routine safety monitoring and development of a
                  central Adverse Event (AE) notification  system in conjunction
                  with the CRO or a Thai Government approved committee and PI.
         10.      Assistance  with site and  laboratory  selection  and  quality
                  assurance reviews.
         11.      Travel expenses and other administration and personnel cost of
                  IRC employees.

         RESPONSIBILITIES OF TRINITY MEDICAL GROUP, CO., LTD.

         1.       Funding for expenses  associated  with conducting the clinical
                  trial (data management and  monitoring),  performance of study
                  procedures (such as medical histories,  physical examinations,
                  drug  administration,   venipuncture),  investigator  payments
                  including study site coordinator and other study personnel and
                  all  laboratory   assays  and  testing  (e.  g.,  safety  labs
                  including    hematology   and   chemistries   and   lymphocyte
                  phenotyping -CD4).
         2.       Recruitment  and  follow-up  of patients  which meet  protocol
                  inclusion and exclusion criteria.
         3.       Quality  assurance  monitoring  of  medical  records  and case
                  report  forms  which  would  meet   worldwide   Good  Clinical
                  Practices (GCPs) requirements.
         4.       Preparation of Thailand regulatory submissions and translation
                  of all required documents.
         5.       Importing Product into Thailand.

                             ----------------------

         ***      Confidential Material redacted and filed separately


                                      -2-