<PAGE>   1
                                                                  EXHIBIT 10.9

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

                          EASY ASSAY LICENSE AGREEMENT


         THIS AGREEMENT, dated September 22, 1995, is entered into by and
between SANDOZ PHARMA LTD., a Swiss Corporation with offices at Lichtstrasse 35,
CH-4002 Basle/Switzerland ("SANDOZ") and BIOSITE DIAGNOSTICS INCORPORATED, a
Delaware corporation with offices at 11030 Roselle Street, San Diego, CA
921211/USA ("LICENSEE").

                              W I T N E S S E T H:

         WHEREAS, SANDOZ and LICENSEE have entered into an ANTIBODY LICENSE
AGREEMENT of even date herewith, pertaining to diagnostic assays utilizing
monoclonal antibodies for measuring levels of the immunosuppressant cyclosporine
in blood and plasma;

         WHEREAS, SANDOZ has developed an improved monoclonal antibody based
assay for measuring cyclosporine levels in blood and plasma, which improved
assay further comprises compound capable of [CONFIDENTIAL MATERIAL REDACTED AND
FILED SEPARATELY WITH THE COMMISSION], for which improved assay SANDOZ owns
patents, patent applications, technical information, data, and know-how, and
which improved assay, because it can be conducted in a short period of time
without the need for laboratory equipment or special skills, is particularly
well suited for use in connection with small portable fluorometers;

         WHEREAS, LICENSEE has particular expertise in the development and
marketing of assays for use in connection with small portable fluorometers;

   
         WHEREAS, SANDOZ and LICENSEE desire that LICENSEE should develop and
market a hand-held, rapid monoclonal antibody-based cyclosporine assay utilizing
SANDOZ's improved assay technology and capable of being read by LICENSEE's
portable fluorometer, to be marketed using SANDOZ trademarks;
    

         IT IS NOW, THEREFORE, for good and valuable consideration, the receipt
and adequacy of which is hereby acknowledged, agreed as follows:

         1.       PROVISIONS INCORPORATED FROM ANTIBODY LICENSE
                  AGREEMENT.

         The provisions of Articles 1 (Definitions), 6 (Verification), 7
(Government Approvals), 8 (Confidential Information), 9 (Patents), 11 (Governing
Law and Jurisdiction), 12 (Notices), 14 (Excused Non-Performance), 15
(Severability), and

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16 (Publicity and Promotional Activities) of the ANTIBODY LICENSE AGREEMENT
between the parties of even date herewith, and such other provisions of the
ANTIBODY LICENSE AGREEMENT as are specifically referenced below shall also be
applicable to this Agreement, mutatis mutandis, and are incorporated herein by
reference. A copy of the ANTIBODY LICENSE AGREEMENT is attached hereto and made
a part of this Agreement.

         2. ADDITIONAL DEFINITIONS.

         In addition to the definitions in the ANTIBODY LICENSE AGREEMENT, the
following definitions will apply to this Agreement:

         2.1 [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
COMMISSION]

   
         2.2 "CyA EASY Assays" shall refer to a CyA Assay which, in addition to
a Monoclonal Antibody, further comprises a [CONFIDENTIAL MATERIAL REDACTED AND
FILED SEPARATELY WITH THE COMMISSION]
    

         2.3 "SANDOZ EASY Know-How" shall mean all biological, chemical, and
immunological materials, methods and other technical information, presently or
hereafter during the term of this Agreement in the possession or control of
SANDOZ which relate to [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH
THE COMMISSION] or to CyA EASY Assays, and which is conveyed to LICENSEE in
writing, orally or through other tangible materials.

         2.4 "SANDOZ EASY Patent Rights" shall mean all patent applications
worldwide and patents granted thereon, and all extensions and supplemental
protection certificates based on such patents, now or hereafter during the term
of this Agreement owned or controlled by SANDOZ, which incorporate one or more
claims covering [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
COMMISSION] or CyA EASY Assays which has not been declared to be invalid or
unenforceable by the final judgment of a court of competent jurisdiction from
which no appeal can be or has been taken; a listing of such subsisting SANDOZ
EASY Patent Rights being provided in the attached SCHEDULE B, which will be
updated from time to time as appropriate.

         2.5 "EASY Patent Countries" shall mean countries in which SANDOZ EASY
Patent Rights subsist.

         2.6 "Net EASY Sales" shall mean the gross sales of CyA EASY Assays by
LICENSEE, its Affiliates and its sublicensees (if any) billed to customers, less
the amount actually allowed to customers for (1) adjustments granted to
customers, including without limitation credits and allowances or on account of
the rejection or return of CyA EASY Assays previously sold, (2) trade and cash
discounts, rebates and distributor fees, (3) transportation, insurance and
handling charges and (4) sales, excise, turnover and similar taxes and any
duties and

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<PAGE>   3
other governmental charges imposed upon the production, importation, use or sale
of CyA EASY Assays. Where the price of a CyA EASY Assay includes the price of
the device reader or the price of an assay for a compound other than CyA, Net
EASY Sales shall be determined by a formula (to be agreed upon by the parties
before sales at such price are made) calculated to exclude that portion of sales
of CyA EASY Assays reasonably attributable to such prices of the device reader
and/or the assay for a compound other than CyA.

         2.7 "SANDOZ Trademarks" shall mean the trademarks listed on the
attached SCHEDULE C.

         3. FEASIBILITY.

   
         3.1 To demonstrate feasibility, a CyA EASY Assay developed by LICENSEE
(i) must meet the feasibility criteria for a CyA Assay as set forth in section 2
of the ANTIBODY LICENSE AGREEMENT, the provisions of which shall apply, mutatis
mutandis, to this Agreement; (ii) must be capable of being read by a small
portable fluorometer, total dimensions not to exceed two hundred-fifty (250)
cubic inches; and (iii) must be capable of being utilized and read at room
temperature (15-30 degrees C) within fifteen (15) minutes or less.
    

   
         3.2 In addition to providing CyA standards, Monoclonal Antibody and CyA
Metabolites as provided in section 2 of the ANTIBODY LICENSE AGREEMENT, SANDOZ
will also provide [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
COMMISSION] to develop and demonstrate feasibility of its CyA EASY Assay.
    

         4. LICENSES.

   
         4.1 Upon proof of feasibility of the CyA EASY Assay pursuant to Article
3.1 of this Agreement and receipt of the notification referred to in Article 2.4
of the Antibody Assay Agreement, SANDOZ undertakes to grant to LICENSEE a
License under SANDOZ EASY Patent Rights and SANDOZ EASY Know-How to make, have
made, use and sell CyA EASY Assays worldwide. For CyA EASY Assays intended to be
read by hand-held fluorometers with total dimensions less than 250 cubic inches,
this License shall be exclusive.  For CyA EASY Assays intended to be read by
other types of readers (in particular by fully automated, random access, high
throughput immunoassay system analyzers, including but not limited to the
Abbott TDx, IMx and AxSym assay readers and the like, or by radiometers of any
type), this License shall be non-exclusive.
    

   
         4.2 Simultaneously with the grant of the License under Article 4.1 of
this Agreement, SANDOZ further undertakes to grant LICENSEE a Non-exclusive
License to use the SANDOZ trademarks to identify and promote the sale of CyA
EASY Assays manufactured and sold anywhere in the world pursuant to this
Agreement.
    

   
         4.3 All CyA EASY Assays sold by LICENSEE pursuant to this Agreement
shall be marked or otherwise identified using the SANDOZ trademarks, as provided
in Article 11 of this Agreement.
    


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         4.4 Sublicense of any License granted under this Agreement other than
to Affiliates of LICENSEE shall require the express written consent of SANDOZ.
In the event of any sublicense, LICENSEE shall undertake to ensure that the
performance of such sublicensee complies with all terms and conditions of this
Agreement to the same extent as if performed by LICENSEE directly.

         5. SUPPLIES OF [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY
WITH THE COMMISSION].

         5.1 In order to ensure the good and consistent quality of the CyA EASY
Assays, SANDOZ shall supply LICENSEE and LICENSEE shall purchase from SANDOZ all
requirements of [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE
COMMISSION] reasonably and justifiably needed for the purpose of development and
production of CyA EASY Assays following proof of feasibility, in accordance with
the provisions of this Article 5.

   
         SANDOZ, however, may terminate at its sole discretion by written
previous notice of one year, its obligation to provide such materials to
LICENSEE, provided it makes available the know-how to manufacture such
[CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] to
LICENSEE within one (1) month after the date of such notification.  The
Non-exclusive Licenses granted to LICENSEE hereunder shall not be affected
thereby.
    

   
         5.2 At the latest three months before the beginning of any calendar
quarter LICENSEE shall place a firm order with SANDOZ in writing for the first
quarter and indicate to SANDOZ its estimated requirement for each of the
following three quarters and the subsequent 12 months. SANDOZ has no commitment
to supply any quantities of LICENSEE's requirements exceeding by twenty-five
percent (25%) the last estimate given for such quarter. In the event that SANDOZ
is unwilling or unable to supply any quantities of LICENSEE's requirements
exceeding by twenty-five percent (25%) the last estimate given for such quarter,
then LICENSEE shall have the right to purchase the [CONFIDENTIAL MATERIAL
REDACTED AND FILED SEPARATELY WITH THE COMMISSION] elsewhere or to prepare this
compound internally.
    

   
         Freight, duty and associated taxes shall be paid by LICENSEE with each
element shown separately in invoices. Title shall pass to LICENSEE upon transfer
to the carrier by SANDOZ for final shipment to LICENSEE. Delivery shall be made
to LICENSEE within forty-five (45) working days of the date of LICENSEE's order
therefor.
    

         5.3 The supply price for [CONFIDENTIAL MATERIAL REDACTED AND FILED
SEPARATELY WITH THE COMMISSION] shall be [CONFIDENTIAL MATERIAL REDACTED AND
FILED SEPARATELY WITH THE COMMISSION] per gram FCA Basel (1992-SFr). In the
event that the contribution of the cost [CONFIDENTIAL MATERIAL REDACTED AND
FILED SEPARATELY WITH THE COMMISSION] at this supply price to the total
production cost of the CyA EASY Assay exceeds [CONFIDENTIAL

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MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION], this supply price
may be renegotiated. LICENSEE may purchase less than one gram of such materials
at pro rata cost.

         6. FEES AND ROYALTIES.
   
        6.1 In addition to the fees payable under the ANTIBODY LICENSE
AGREEMENT, LICENSEE shall pay to SANDOZ a non-refundable payment of Swiss Francs
500,000 (five hundred thousand) as follows: (a) upon execution of this
Agreement, LICENSEE shall pay to SANDOZ the amount of Swiss Francs 250,000 (two
hundred fifty thousand); and (b) upon the date of first commercial sale of the
CyA EASY Assays, LICENSEE shall pay SANDOZ the amount of Swiss Francs 250,000
(two hundred fifty thousand). Of this payment, Swiss Francs 250,000 (two
hundred fifty thousand) shall be creditable against up to 50% of any royalties
due under Article 6.2 of this Agreement.
    
         6.2 In addition to the royalties payable under the ANTIBODY LICENSE
AGREEMENT, LICENSEE shall pay to SANDOZ the following royalties:

         a. For sales in each EASY Patent Country, LICENSEE shall pay a royalty
of [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] of
Net EASY Sales in such county for such time as one or more of SANDOZ EASY Patent
Rights covers the sale by LICENSEE of CyA EASY Assays in such country, following
which the royalty shall be reduced to [CONFIDENTIAL MATERIAL REDACTED AND FILED
SEPARATELY WITH THE COMMISSION] of Net EASY Sales.

         b. For sales in all other countries, LICENSEE shall pay a royalty of
[CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] on all
Net EASY Sales.

         c. With respect to sale of CyA EASY Assays in any EASY Patent Country,
the obligation of LICENSEE to pay royalties as provided above shall be reduced
by [CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION] in
the event and for the period that an unlicensed third party or parties sell any
quantity of CyA EASY Assays in excess of [CONFIDENTIAL MATERIAL REDACTED AND
FILED SEPARATELY WITH THE COMMISSION] of the total market in such EASY Patent
Country for CyA EASY Assays, said market share percentage to be determined by an
independent market survey organization mutually agreed to by SANDOZ and
LICENSEE.

         6.3 Articles 5.4 through 5.12 of the ANTIBODY LICENSE AGREEMENT,
concerning calculation and payment of royalties for CyA Assays shall apply,
mutatis mutandis, to calculation and payment of royalties for CyA EASY Assays.


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         6.4 If after the date of this Agreement, Sandoz grants to another
licensee a similar licence of Sandoz Easy Patent Rights and Sandoz Easy
Know-How, with fees and royalties more favorable to such other licensee than as
provided in this Article 6, this Article 6 will be adapted prospectively to
conform with such more favorable terms.
    

         7. QUALITY CONTROL.

         7.1 As soon as reasonably practicable after completion of the
feasibility study under Article 3 of this Agreement, LICENSEE shall establish
and submit to SANDOZ for approval, which shall not be unreasonably withheld or
delayed, initial quality control standards, which shall include objective
standards for assay sensitivity, specificity, range, stability and failure
profile of readers. LICENSEE shall manufacture, or cause to be manufactured, the
CyA EASY Assays according to such standards.

         LICENSEE shall comply with all applicable Good Manufacturing Practices
and with all standards and requirements of regulatory authorities in the
countries in which LICENSEE sells or supplies CyA EASY Assays.

   
         These quality control standards will apply regardless of whether
failure to meet such standards is due to a defect in the CyA EASY Assay itself
or a defect in the fluorometer supplied by the LICENSEE. LICENSEE shall monitor
quality to ensure that these standards are maintained. LICENSEE shall provide
SANDOZ with periodic certificates to ensure that these quality control standards
are maintained, and upon fourteen (14) days advance notice, SANDOZ (or such
independent consultants as SANDOZ may designate) shall have the right at its
sole expense to visit LICENSEE's facilities to inspect the manufacturing,
packaging, and storage of the CyA EASY Assays by LICENSEE.
    

         7.2 LICENSEE shall develop and submit to SANDOZ for approval, which
approval shall not be unreasonably withheld or delayed, supply standards which
shall set forth inventory control procedures, targets for delivery times and
procedures for informing sales personnel of supply constraints, and LICENSEE
shall use commercially reasonable efforts to ensure that CyA EASY Assays, or
fluorometers for reading such CyA EASY Assays, sold or supplied by LICENSEE in
any country shall be delivered to the customer within a reasonable time and not
later than the time promised to the customer. LICENSEE shall monitor orders,
supplies, and the time required to fill orders and shall ensure that sales
representatives are aware of supply constraints.

         7.3 LICENSEE shall promptly advise SANDOZ of serious problems or
alleged problems with supply and/or quality of the CyA EASY Assays, e.g., as
reflected by customer complaints, letters from regulatory authorities, lawsuits,
regulatory actions, internal reports and data, and any other information
alleging, suggesting, stating or evidencing serious problems exist with the
quality or reliable supply of the CyA EASY

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<PAGE>   7
Assays. LICENSEE shall take immediate steps to investigate and use commercially
reasonable efforts to resolve such problems.

         8. COMMERCIALLY REASONABLE EFFORTS.

         8.1 LICENSEE shall use commercially reasonable efforts to develop and
obtain FDA approval to manufacture and sell a CyA EASY Assay which meets the
feasibility requirements of Article 3 of this Agreement, and shall thereafter
diligently develop, manufacture, market and sell such CyA EASY Assays in
accordance with this Agreement for the duration of this Agreement.

         9. PRODUCTS LIABILITY.

   
         9.1 LICENSEE shall indemnify and hold harmless SANDOZ and its
Affiliates and their respective directors, officers, employees and consultants
from all losses, liabilities, damages and expenses (including reasonable
attorneys' fees and costs) that they may suffer as a result of any claims,
demands, actions or other proceedings made or instituted by any third party
against any of them and which arise or result from defects or alleged defects in
any CyA EASY Assays or fluorometers manufactured, distributed or sold pursuant
to this Agreement, except for claims made or suits brought which arise or result
from defects in CyA, CyA Metabolites, or [CONFIDENTIAL MATERIAL REDACTED AND
FILED SEPARATELY WITH THE COMMISSION] supplied by SANDOZ or its Affiliates which
materials have been handled, used and stored by LICENSEE (or those under
LICENSEE's direction or control) in accordance with SANDOZ's instructions.
    

   
         9.2 SANDOZ shall indemnify and hold harmless LICENSEE and its
respective directors, officers, employees and consultants from all losses,
liabilities, damages and expenses (including reasonable attorneys' fees and
costs) that they may suffer as a result of any claims, demands, actions or other
proceedings made or instituted by any third party against any of them and which
arise or result from defects or alleged defects in CyA, CyA Metabolites, or
[CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION]
supplied by SANDOZ or its Affiliates, which materials have been handled, used
and stored by LICENSEE (or those under LICENSEE's direction or control) in
accordance with SANDOZ's instructions.
    

         9.3 The indemnity obligations under this Article 9 shall not apply to
amounts paid in settlement of any loss, claim, damage, liability or action if
such settlement is effected without the consent of the indemnitor, which consent
shall not be withheld unreasonably. 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 of any action,
claim or liability covered by this indemnification.


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         9.4 Both parties shall undertake to ensure that they maintain
reasonably adequate insurance or liquid reserves to cover potential claims under
this Article 9.


         10. EASY ASSAY DEVELOPMENT AND MANUFACTURE.

         10.1 LICENSEE shall conduct the research, development and
commercialization of the CyA EASY Assays, of the fluorometers necessary to read
such assays, and of such operating software (including EPROMs and the like) as
may be required to operate the fluorometers.

         10.2 LICENSEE, in consultation with SANDOZ, will endeavor to develop
operating software that will calculate patient exposure to CyA following
administration of a microemulsion preconcentrate formulation of CyA, based on
the level of CyA in the test sample, the dosage of CyA received by the patient,
and the time of administration.

         11. MARKETING, SALES, DISTRIBUTION, AND USE OF TRADEMARKS.

         11.1 The parties will each nominate three members to a Steering
Committee, which will meet periodically to discuss any issues which might arise
concerning the accuracy, ease of use, reliability, manufacturing and
distribution capacity, and other issues relating to the performance and
availability of the assays. Each party will appoint one Steering Committee
member to be the primary contact person.

         11.2 The exact manner and style of marking and labeling the CyA EASY
Assays produced or sold by LICENSEE will be discussed and agreed between the
parties; however:

   
         i. all CyA EASY Assays sold pursuant to this Agreement, and at the
option of SANDOZ, such of LICENSEE's fluorometers as would only be suitable for
use in connection with such CyA EASY Assays, shall bear a SANDOZ Trademark
(alone, and/or in the form of a logo, and/or in conjunction with a longer
identification, e.g. "NEORAL Cyclosporine Assay" or the like);
    

         ii. no SANDOZ trademark shall be used in combination with another
trademark in a manner which may suggest that it is owned by LICENSEE or another
party, and with each public use of a SANDOZ Trademark, whether on a label,
promotional item, package, or other presentation to the public, LICENSEE shall
expressly acknowledge SANDOZ's ownership of the SANDOZ Trademark, e.g., with a
legend stating "[SANDOZ Trademark] is a registered trademark of SANDOZ LTD" or
words to that effect;

   
         iii. registration and maintenance of the SANDOZ Trademarks shall be the
responsibility of SANDOZ; however, LICENSEE agrees to cooperate with SANDOZ and
to execute such documents and provide such information as may be reasonably
necessary to register and maintain the SANDOZ Trademarks and where required to
register the trademark license granted hereunder with the appropriate
authorities;
    


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<PAGE>   9
         iv. each party shall have the right to require that its company name
and trademarks appear on the labeling or packaging for the CyA EASY Assays; and

         v. each party shall use commercially reasonable efforts to ensure that
the labeling and packaging of the CyA EASY Assays complies with all applicable
laws and regulations.

         11.3 Any and all labels, logos, promotional materials, packaging or
other presentation to the public which contains or depicts a SANDOZ Trademark
must be approved by SANDOZ before use or distribution. All public statements by
LICENSEE concerning the properties, activities, bioavailability or other
characteristics of any cyclosporine formulations, including statements in
promotional materials, package inserts, articles, or other public disclosures,
must be approved in advance by SANDOZ.

         11.4 In all countries where the CyA EASY Assays are sold by LICENSEE,
including the United States, SANDOZ shall have the option to co-promote
LICENSEE's CyA EASY Assays. In the event of co-promotion, each party agrees to
use its commercially reasonable efforts for the cooperative and coordinated
marketing, sale, and distribution of CyA EASY Assays. Coordinated marketing
efforts may include the following activities, which will be reviewed and agreed
to by a joint marketing team:

         a. Co-promotion of test kits to the transplant community via trade
shows, trade communications, advertising, etc.;

   
         b. Joint sales presentations by LICENSEE's sales representatives and
SANDOZ sales representatives to transplant professionals in an effort to provide
complete, accurate, and consistent information regarding CyA EASY Assays,
particularly in connection with their use in monitoring SANDOZ's microemulsion
preconcentrate formulation of CyA, and regarding the relationship between the
readout from LICENSEE's CyA EASY Assay and the pharmacokinetics of SANDOZ's
microemulsion preconcentrate formulation of CyA;

         c. Cooperative programs in which CyA EASY Assays and SANDOZ's
microemulsion preconcentrate formulation of CyA are offered as a package based
on purchase sales levels or other considerations.

         In the event of co-promotion, both parties agree to use their
commercially reasonable efforts to co-promote CyA EASY Assays of LICENSEE so as
to maximize sales of both LICENSEE's CyA EASY Assays and SANDOZ's microemulsion
preconcentrate formulation of CyA. Sales of LICENSEE's CyA EASY Assays as a
result of co-promotion under this Article 11.4 shall be made by LICENSEE, and no
compensation would be due to SANDOZ with respect to such sales other than as
provided under Article 6 hereof. Should the parties decide that it would be
appropriate for SANDOZ to sell directly in some cases, however, such sales would
be governed by Article 11.6 hereof.

         11.5 Sales and distribution channels for LICENSEE's CyA EASY Assay
product shall be discussed with SANDOZ on a country-by-country basis. All sales
and distribution shall be by LICENSEE or its Affiliate(s) unless otherwise
agreed, except as provided in Article 11.4 hereof. SANDOZ reserves the right to
approve all distribution via third parties in the
    


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<PAGE>   10
   
USA, Japan, and Europe (including Switzerland and all countries in the European
Economic Area), provided that SANDOZ must raise any objections to any proposal
by LICENSEE for distribution by third parties within sixty (60) days of receipt
of such proposal in writing from LICENSEE. In the event of any distribution by
third parties, LICENSEE shall undertake to ensure that such distribution
complies with all terms and conditions of this Agreement to the same extent as
if performed by LICENSEE directly.
    

         11.6 In some countries, SANDOZ and LICENSEE may enter into arrangements
wherein SANDOZ sales representatives in a particular country would undertake to
sell CyA EASY Assays manufactured by LICENSEE. In such a case, it is foreseen
that such sales by SANDOZ sales representatives would be booked by LICENSEE and
SANDOZ would receive a commission in the amount of [CONFIDENTIAL MATERIAL
REDACTED AND FILED SEPARATELY WITH THE COMMISSION] (or such other amount as may
be agreed on by the parties) on Net EASY Sales of LICENSEE's CyA EASY Assays
attributable to SANDOZ sales representatives in such countries. Any royalties
due to SANDOZ on such sales pursuant to this Agreement and/or the ANTIBODY
LICENSE AGREEMENT would be creditable against such commissions.

         12. TERM AND TERMINATION.

   
         12.1 This Agreement shall extend indefinitely unless earlier
terminated by agreement of the parties or pursuant to this Article 12.

         12.2 LICENSEE shall have the right to terminate this Agreement
at any time upon one year's written notice.

         12.3 If the ANTIBODY LICENSE AGREEMENT is terminated before the later
of the following dates (i) the date of expiration of the last-to-expire patent
included in Sandoz Patent Rights; or (ii) the date of expiry of a ten (10) year
period from the date of first Commercial Sale in the last country in which CyA
Assays are launched, either party shall have the right to terminate this
Agreement effective as of the date of the termination of the ANTIBODY LICENSE
AGREEMENT.

         12.4 Either party shall have the right to terminate this Agreement and
the licenses granted hereunder forthwith by notice in writing to the other party
if the other party fails to perform or observe any of the material terms hereof
on its part to be performed and observed, and fails to remedy such breach within
ninety (90) days of a notice to remedy the same (such notice giving adequate
particulars of the alleged default and of the intention of the party serving the
notice to terminate this Agreement under this Article) or, if the breach is one
which requires more than ninety (90) days to remedy, the remedying was not
commenced promptly and thereafter diligently pursued.
    

         12.5 SANDOZ shall have the right to terminate the Non-exclusive License
to use the SANDOZ Trademarks granted under

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<PAGE>   11
   
Article 4.2 of this Agreement forthwith in the event that another entity
acquires direct or indirect beneficial ownership of at least fifty percent (50%)
of the voting interest in, or a greater than fifty percent (50%) interest in the
equity of LICENSEE, or that LICENSEE is merged with another company, transfers
substantially all of its assets to another company, declares bankruptcy, or is
adjudged insolvent. In the event that SANDOZ exercises this right, the License
granted under Article 4.1 of this Agreement will become non-exclusive, and the
royalties falling due under this Agreement from and after such time as SANDOZ
exercises this right will be reduced by [CONFIDENTIAL MATERIAL REDACTED AND
FILED SEPARATELY WITH THE COMMISSION] and will be payable in each country
only until the later of the following dates: (i) the date of expiration of the
last to expire patent included in the EASY Patent Rights in such country or (ii)
the date of expiry of a period which is ten (10) years from first Commercial
Sale of a CyA EASY Assay in such country, following which time LICENSEE's
successor shall have a paid up license to make, have made, use and sell CyA Easy
Assays for such country.

         12.6 Upon the later of the following dates: (i) the date of expiration
of the last-to-expire patent included in the EASY Patent Rights or (ii) the date
of expiry of a period which is ten (10) years from the first Commercial Sale of
a CyA EASY Assay in the last country in which the CyA EASY Assay is launched,
LICENSEE shall have the right to terminate the Non-exclusive License to use the
SANDOZ Trademarks granted under Article 4.2 of this Agreement. In the event that
LICENSEE exercises this right, the License granted under Article 4.1 of this
Agreement will become non-exclusive, and LICENSEE shall have a paid up license
to make, have made, use and sell CyA EASY assays, but shall have a right to use
the SANDOZ Trademarks.

         12.7 In the event that LICENSEE discovers that quality control or
supply standards under Article 7 of this Agreement have not been met, LICENSEE
(i) shall notify SANDOZ immediately and (ii) shall have ninety (90) days from
such discovery to cure such deficiencies, or if any such deficiency is one which
requires more than ninety (90) days to cure, LICENSEE shall commence promptly
and thereafter diligently pursue cure of such deficiency, failing which cure,
SANDOZ shall have the right to terminate this Agreement forthwith.
    

         12.8 Any termination of this Agreement (a) shall automatically cancel
the licenses granted to LICENSEE hereunder; (b) shall be without prejudice to
the rights of either party against the other party which may have accrued up to
the date of such termination (including SANDOZ's right to be paid any amounts
due and payable hereunder); and (c) shall be without prejudice to the rights of
LICENSEE to dispose of quantities of CyA EASY Assays in its possession, subject
to the payment of any amounts due thereon to SANDOZ as provided herein.

   
         12.9 In the event of any termination of this Agreement other than as a
result of mutual agreement of the parties or breach by SANDOZ of this Agreement,
the ANTIBODY LICENSE AGREEMENT, or the Debenture Purchase Agreement, LICENSEE
shall (i) grant to SANDOZ a worldwide, non-exclusive license (royalty to be
negotiated in good faith) with right of sublicense to Affiliates to make, have
made, use and sell the CyA EASY Assays developed by LICENSEE, (ii) within one
month shall provide to SANDOZ any know how necessary to produce such assays,
and (iii) shall agree to supply to SANDOZ or its sublicensee, or shall
authorize its supplier to supply to SANDOZ or its sublicensee, or shall provide
to SANDOZ or its sublicensee the necessary license (royalty to be negotiated in
good faith) with right of sublicense to Affiliates to make, have made, use and
sell, fluorometers of the same type sold by LICENSEE and suitable for use in
connection with LICENSEE's CyA EASY Assays.
    

                                      -11-

<PAGE>   12
         13. ENTIRE AGREEMENT.

         13.1 This Agreement, the ANTIBODY LICENSE AGREEMENT and the Debenture
Purchase Agreement, all by and between SANDOZ and LICENSEE and all of even date,
constitute the entire understanding and agreement of the parties with respect to
the subject matter of such agreements and supersede all previous negotiations,
representations, and writings. No variation or modification of any of these
agreements or waiver of any terms or provisions thereof shall be valid unless in
writing and signed by the appropriate parties thereto. Breach of any of these
three agreements shall be considered a breach of all three agreements.

         IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed by their duly authorized representatives as of the date first written
above.

                                       SANDOZ PHARMA LTD.



                                       By /s/ D. Vasella
                                          --------------------------
                                       Name: D. Vasella
                                             -----------------------
                                       Title: CEO
                                             -----------------------


                                       By /s/ C.S. Morris
                                          --------------------------
                                       Name: C.S. Morris
                                             -----------------------
                                       Title: V.P.
                                             -----------------------

                                       BIOSITE DIAGNOSTICS, INCORPORATED


                                       By /s/ Kim D. Blickenstaff
                                          --------------------------
                                       Name: Kim D. Blickenstaff
                                             -----------------------
                                       Title: President & CEO
                                             -----------------------

                                      -12-

<PAGE>   13
                                   Schedule B

                      Listing of SANDOZ EASY Patent Rights

As of 15 September 1995, SANDOZ has been granted the following patents covering
[CONFIDENTIAL MATERIALS REDACTED AND FILED SEPARATELY WITH THE
COMMISSION].

<TABLE>
<CAPTION>
=========================================================================================================================
               Country                              Patent Numbers                            Expiry date*
-------------------------------------------------------------------------------------------------------------------------
<S>                                      <C>                                                    <C>
Australia                                623078                                                 17/06/04
-------------------------------------------------------------------------------------------------------------------------
Austria                                  0296123                                                15/06/08
-------------------------------------------------------------------------------------------------------------------------
Belgium                                  0296123                                                15/06/08
-------------------------------------------------------------------------------------------------------------------------
Canada                                   569655**                                               16/06/08
-------------------------------------------------------------------------------------------------------------------------
Denmark                                  3352/88***                                             17/06/08
-------------------------------------------------------------------------------------------------------------------------
England                                  0296123                                                15/06/08
-------------------------------------------------------------------------------------------------------------------------
Finland                                  87928                                                  17/06/08
-------------------------------------------------------------------------------------------------------------------------
France                                   0296123                                                15/06/08
-------------------------------------------------------------------------------------------------------------------------
Germany                                  P3851268.8                                             15/06/08
-------------------------------------------------------------------------------------------------------------------------
Greece                                   0296123                                                15/06/08
-------------------------------------------------------------------------------------------------------------------------
Holland                                  0296123                                                15/06/08
-------------------------------------------------------------------------------------------------------------------------
Hungary                                  204101                                                 17/06/08
-------------------------------------------------------------------------------------------------------------------------
Ireland                                  1838/88                                                15/06/08
-------------------------------------------------------------------------------------------------------------------------
Israel                                   86789                                                  17/06/08
-------------------------------------------------------------------------------------------------------------------------
Italy                                    0296123                                                15/06/08
-------------------------------------------------------------------------------------------------------------------------
Japan                                    151056/88***                                           18/06/08
-------------------------------------------------------------------------------------------------------------------------
Luxembourg                               0296123                                                15/06/08
-------------------------------------------------------------------------------------------------------------------------
Malaysia                                 103735                                                 30/09/08
-------------------------------------------------------------------------------------------------------------------------
New Zealand                              225071                                                 17/06/04
-------------------------------------------------------------------------------------------------------------------------
Nigeria                                  10516                                                  17/06/08
-------------------------------------------------------------------------------------------------------------------------
Pakistan                                 131350                                                 16/06/04
-------------------------------------------------------------------------------------------------------------------------
Philippines                              25933                                                  19/12/08
-------------------------------------------------------------------------------------------------------------------------
Portugal                                 87763                                                  14/04/07
-------------------------------------------------------------------------------------------------------------------------
Poland                                   159763                                                 04/07/03
-------------------------------------------------------------------------------------------------------------------------
South Africa                             88/4344                                                17/06/08
-------------------------------------------------------------------------------------------------------------------------
South Korea                              7371/88                                                18/06/08
-------------------------------------------------------------------------------------------------------------------------
Spain                                    0296123                                                15/06/08
-------------------------------------------------------------------------------------------------------------------------
Sweden                                   0296123                                                15/06/08
-------------------------------------------------------------------------------------------------------------------------
Switzerland                              0296123                                                15/06/08
-------------------------------------------------------------------------------------------------------------------------
Taiwan                                   NI-45155                                               10/03/06
-------------------------------------------------------------------------------------------------------------------------
United States                            5116816                                                26/05/09
=========================================================================================================================
</TABLE>
*        The expiry date is calculated without considering the possibility of
         patent term extension, which may be available in some cases.

**       Application allowed; patent number not yet known.

                                      -13-

<PAGE>   14
***      Application pending; not yet granted.

   
SANDOZ additionally owns PCT application WO 95/07468 which claims the EASY assay
and related assay systems for immunophilin binding compounds. Patents resulting
from this application will expire in 2014 in most countries, not counting
possible extensions.
    

                                      -14-

<PAGE>   15
                                   SCHEDULE C

   
         SANDOZ owns several trademarks relating to its proprietary
microemulsion preconcentrate formulation of cyclosporine.  The trademark used
by SANDOZ to brand its formulation may vary somewhat from country to country
but is generally one of the following:

                        NEORAL
                        SANDIMMUN NEORAL
                        SANDIMMUNE NEORAL

                        OPTORAL
                        SANDIMMUN OPTORAL
                        SANDIMMUNE OPTORAL
    



                                      -15-