<PAGE>
 
                                                                   EXHIBIT 10.90


                         Option and License Agreement

     This Agreement ("Agreement") is entered into as of the 6th day of July,
1998, by and between RiboGene, Inc., a corporation organized under the laws of
Delaware ("RiboGene"), and Roberts Pharmaceutical Corporation ("Roberts"), a
corporation organized under the laws of New Jersey.

                                   Recitals

     Whereas, RiboGene has conducted research and development with an
intranasally administered pharmaceutical product containing metoclopramide as an
active ingredient for the treatment of delayed onset emesis and other
indications, and owns certain patents relating thereto; and

     Whereas, Roberts is interested in completing the development of RiboGene's
product as a contract research organization for RiboGene, and desires to obtain
an exclusive option for obtaining a license to market said product after
regulatory approvals have been obtained;

     Whereas, RiboGene and Roberts have entered into that certain Series A
Preferred Stock Purchase Agreement, dated as of the date hereof, (the "Purchase
Agreement"), pursuant to which Roberts will purchase 1,428,572 shares of Series
A Convertible Non-voting Preferred Stock of RiboGene (the "Stock Purchase");

     Now, Therefore, in consideration of the foregoing and the covenants and
promises contained herein, and subject to the Closing of the Stock Purchase, the
parties agree as follows:

                                   ARTICLE 1

                                  DEFINITIONS

     1.1  "Affiliate" shall mean (i) any corporation or other entity ("Parent")
which directly or indirectly owns or controls at least fifty percent (50%) of
the outstanding voting securities of a party, (ii) any corporation or other
entity in which a party owns or controls at least fifty percent (50%) equity
interest, and (iii) any corporation or other entity in which a Parent of a party
owns or controls at least a fifty percent (50%) equity interest.

     1.2  "Allowable Expenses" shall mean the pre-existing third party
commitments and any patent and trademark costs in the Territory incurred by
RiboGene relating to the Product, an estimate of which is contained in Exhibit
A.

     1.3  "Closing" shall have the meaning specified in the Purchase Agreement.

     1.4  "Collaboration Know-How" shall mean all inventions, discoveries,
materials and information developed by either party relating to the Product
during the term of this Agreement. Collaboration Know-How shall not include
Collaboration Patents.

     1.5  "Collaboration Patents" shall mean any and all patents, including,
without limitation, any substitutions, extensions, reissues, renewals,
supplementary protection certificates 

                                       1.
<PAGE>
 
and inventors' certificates, which have not been held invalid or unenforceable
by a non-appealable or non-appealed decision of a court of competent
jurisdiction, issuing from patent applications filed in any jurisdiction,
including, without limitation, any provisionals, divisionals, continuations, and
continuations-in-part, which cover inventions or discoveries made by either
party alone or both parties jointly relating to the Product during the term of
this Agreement.

     1.6  "Collaboration Technology" shall mean all Collaboration Patents and
Collaboration Know-How.

     1.7  "Confidential Information" shall mean a party's confidential
information, including, without limitation, Roberts Know-How, RiboGene Know-How,
Collaboration Know-How, Development Programs, engineering designs and drawings,
research data, manufacturing processes and techniques, scientific,
manufacturing, marketing, and business plans, financial or personnel matters
relating to the party, its present or future products, sales, suppliers,
customers, employees, investors or business.

     1.8  "Development Program" shall mean the program of preclinical and
clinical development activities relating to the Product undertaken by Roberts
pursuant to this Agreement.

     1.9  "Effective Date" shall mean the date on which the Closing occurs, as
defined in the Purchase Agreement.

     1.10 "FDA" shall mean the United States Food and Drug Administration.

     1.11 "Field" shall mean therapeutic treatment of delayed onset emesis and
any other conditions or diseases in humans.

     1.12 "NDA" shall mean the approval required by the FDA or an equivalent 
non-U.S. authority required for the marketing and sale of the Product in the
Territory.

     1.13 "Net Sales" shall mean the gross invoice price of the Product sold in
the Territory by Roberts, its Affiliates or sublicensees to an independent third
party after deducting, if not already deducted in the amount invoiced (a) trade,
quantity and cash discounts actually taken, (b) returns, rebates, chargebacks
and allowances made or granted, and (c) transportation and insurance charges
separately billed. With respect to sales of combination products consisting of
metoclopramide combined with one or more additional active ingredients, the
parties will agree on a method of allocation in the event the situation arises.
Sales among Roberts and its Affiliates or sublicensees shall not be deemed Net
Sales. The Product shall be considered sold when invoiced by Roberts.

     1.14 "Product" shall mean a pharmaceutical product containing
metoclopramide as an active ingredient formulated for intranasal delivery.

     1.15 "RiboGene Know-How" shall mean all inventions, discoveries, materials
and information (i) which RiboGene owns, controls or has a license (with a right
to sublicense) as of the Effective Date or which arise outside the Development
Program during the term of this Agreement, and (ii) which are necessary or 
useful for the conduct of the Development Program, 

                                       2.
<PAGE>
 
or the manufacture, use or sale of the Product. RiboGene Know-How shall not
include RiboGene Patents.

     1.16 "RiboGene Patents" shall mean the patents listed in Exhibit B and any
and all patents other than Collaboration Patents, including, without limitation,
any substitutions, extensions, reissues, renewals, supplementary protection
certificates and inventors' certificates, which have not been held invalid or
unenforceable by a non-appealable or non-appealed decision of a court of
competent jurisdiction, issuing from patent applications filed in any
jurisdiction, including, without limitation, any provisionals, divisionals,
continuations, continuations-in-part, which (i) RiboGene owns, controls or has a
license to (with the right to sublicense) as of the Effective Date, and (ii)
would be infringed by the conduct of the Development Program, or the
manufacture, use or sale of the Product.

     1.17 "RiboGene Technology" shall mean the RiboGene Patents and the RiboGene
Know-How.

     1.18 "Regulatory Approval(s)" shall mean shall mean all new drug approvals,
marketing approvals, applications, licenses, permits, and other authorizations,
which are required for manufacturing and selling the Product in compliance with
applicable laws in the Territory;

     1.19 "Regulatory Authority" shall mean the competent government regulatory
authority responsible for granting the Regulatory Approvals in a country of the
Territory.

     1.20 "Roberts Know-How" shall mean all inventions, discoveries, materials
and information (i) which Roberts owns, controls or has a license to (with a
right to sublicense) as of the Effective Date or which arise outside of the
Development Program from time to time during the term of this Agreement, and
(ii) which are necessary or useful for the conduct of the Development Program,
or the manufacture, use or sale of the Product. Roberts Know-How shall not
include Roberts Patents.

     1.21 "Roberts Patents" shall mean any and all patents other than
Collaboration Patents, including, without limitation, any substitutions,
extensions, reissues, renewals, supplementary protection certificates and
inventors' certificates, which have not been held invalid or unenforceable by a
non-appealable or non-appealed decision of a court of competent jurisdiction,
issuing from patent applications filed in any jurisdiction, including, without
limitation, any provisionals, divisionals, continuations, continuations-in-part,
which (i) Roberts owns, controls or has a license to (with the right to
sublicense) as of the Effective Date, and (ii) would be infringed by the conduct
of the Development Program, or the manufacture, use or sale of the Product.

     1.22 "Roberts Technology" shall mean the Roberts Patents and the Roberts
Know-How.

                                       3.
<PAGE>
 
     1.23 "Steering Committee" shall mean the committee established by the
parties pursuant to Section 2.1.

     1.24 "Territory" shall mean in the United States, its commonwealth and
possessions, Canada and Mexico.

     1.25 "Trademark" shall mean Emitasol(R).

                                   ARTICLE 2

                              PRODUCT DEVELOPMENT

     2.1  Steering Committee.

          (a)  Formation of Steering Committee. Promptly after the Effective
Date, the parties shall establish the Steering Committee. The Steering Committee
shall consist of an equal number of members from Roberts and RiboGene, appointed
and substituted by each party as necessary from time to time. Each member shall
have appropriate technical credentials and knowledge and ongoing familiarity
with the Development Program. All decisions of the Steering Committee shall be
unanimous.

          (b)  Meetings of Steering Committee. The Steering Committee shall meet
quarterly or at such other intervals as shall be agreed between the parties, and
at such times as shall be mutually agreed upon by the parties and at a site
alternating between RiboGene's and Roberts's place of business, or as otherwise
mutually agreed.

          (c)  Responsibilities of the Steering Committee. The Steering
Committee shall establish the Development Program for the Product aimed at
developing and commercializing the Product in all possible indications in all
countries of the Territory. The Steering Committee shall monitor the progress of
the Development Program and may revise it as necessary to achieve the overall
goal of developing the Product as quickly as commercially feasible, and
maximizing the commercial potential of the Product.

     2.2  Conduct of the Development Program.

          (a)  Roberts will conduct the Development Program under the direction
of the Steering Committee. Roberts shall keep the Steering Committee fully
informed on a reasonable basis of the development of the Product, including but
not limited to periodic written updates on the progress of each filing with a
Regulatory Authority.

          (b)  In performing the Development Program, Roberts shall devote the
same degree of attention, resources and diligence to the preclinical and
clinical development of the Product as it devotes to its own high priority
compounds and products. In particular, Roberts undertakes to diligently conduct
clinical trials and to apply for Regulatory Approval of the Product in each
country of the Territory within [     *     ] from the Effective Date. If
Roberts has not filed an NDA or its foreign equivalent in a country of the
Territory within [      *      ] from the Effective Date, Roberts' option
granted under Section 4.1 shall be deemed to 

                                       4.
<PAGE>
 
have expired in such country, and such country shall be excluded from the
Territory. Should an action of a Regulatory Authority outside of Roberts'
control give rise to a reasonable basis to extend the aforesaid [      *      ] 
period, meaning that it is reasonable to expect that Roberts acting with
commercially reasonable diligence shall not have applied for Regulatory Approval
as aforesaid, an extension of time will be provided to enable Roberts to
complete the Development Plan and the parties shall negotiate in good faith and
arrive at a reasonable period of extension.

          (c)  All regulatory filings shall be made in the name of RiboGene, and
any Regulatory Approvals granted thereon shall be transferred to Roberts upon
exercise of the option as set forth in Section 4.2.

     2.3  Manufacture for Development.  Roberts shall be responsible for
obtaining supplies of the Product in quantities necessary for performing the
preclinical and clinical development activities under the Development Program.

     2.4  Access and Use of Information.  RiboGene shall have the right to use
all data obtained in the studies, all filings made, and all Regulatory Approvals
obtained by Roberts in the Territory, and shall have the right to reference any
such data, any regulatory filings and Regulatory Approvals for inclusion in
regulatory submissions such as filings for Regulatory Approvals for the Product
outside of the Territory.

     2.5  Development Funding.  RiboGene shall fund the preclinical and clinical
studies conducted by Roberts under the Development Program, and pay the
Allowable Expenses up to an amount of seven million dollars ($7,000,000)
("Development Funds").  Any costs of activities to be performed under the
Development Program and any Allowable Expenses in excess of the Development
Funds shall be funded by Roberts.  Payments by RiboGene shall be made on a
contract research basis in accordance with a development budget and schedule
established by the Steering Committee in the Development Program.

     2.6  [       *      ]  If at any time during the term of this Agreement and
prior to the exercise of the option by Roberts pursuant to Section 4.2 below [

                                            *

                                                    ]  The [
*
       ] RiboGene at the time when [                         *

          ] or upon the first Regulatory Approval of the Product.  If necessary
to pay for the preclinical and clinical studies under the Development Program or
the Allowable Expenses, [                                            *
] the budget and payment schedule contained in the Development Program or the
due date of the payments for Allowable Expenses.

                                       5.
<PAGE>
 
                                   ARTICLE 3

                OWNERSHIP OF INTELLECTUAL PROPERTY AND LICENSES

     3.1  Roberts Technology.  RiboGene acknowledges and agrees that Roberts is
and shall remain the sole owner of the Roberts Technology and that RiboGene has
no rights in or to any of it other than the license and rights specifically
granted herein and the licenses granted pursuant to this Agreement.

     3.2  RiboGene Technology.  Roberts acknowledges and agrees that RiboGene is
and shall remain the sole owner of the RiboGene Technology and that Roberts has
no rights in or to any of them other than the rights specifically granted herein
and the license to be granted pursuant to this Agreement.

     3.3  Collaboration Technology. Collaboration Technology shall be owned by
either party alone or jointly with the other party depending on whether such
Collaboration Technology was developed by a party alone or jointly with the
other party. Inventorship shall be determined in accordance with the rules of
inventorship under U.S. patent laws. Neither party shall have rights to such
Collaboration Technology owned solely or jointly except as expressly granted
under this Agreement.

     3.4  License Grants.

          (a)  License Grant to Roberts. As of the Effective Date, RiboGene
hereby grants to Roberts a non-royalty bearing, exclusive license under RiboGene
Technology and Collaboration Technology in the Field for the sole purpose of
conducting the Development Program. Roberts may not grant sublicenses under the
license granted in this subsection (a) except in the context of contract
research or contract development by a third party as part of the Development
Program, and then only after the prior written approval of RiboGene, which
approval shall not be unreasonably withheld. The terms of any sublicense shall
conform to the terms of this Agreement in all respects.

          (b)  License Grant to RiboGene. As of the Effective Date, Roberts
hereby grants to RiboGene a non-royalty bearing, non-exclusive license, with the
right to sublicense, under Roberts Technology, and a non-royalty bearing,
exclusive license, with the right to sublicense, under Collaboration Technology
to research, develop, make, have made, use, import, offer for sale and sell the
Product outside of the Territory.

     3.5  Trademark License. As of the Effective Date, RiboGene hereby grants to
Roberts a non-royalty bearing, exclusive license, with the right to sublicense
subject to RiboGene's prior written approval, under RiboGene's rights in and to
the Trademark for the sole purpose of developing, marketing, and selling the
Product in the Territory during the term of this Agreement.  Roberts shall use
the Trademark in connection with the development, marketing, promotion and
selling of the Product.  RiboGene shall file and maintain the Trademark in all
countries of the Territory. The costs of such filings and maintenance shall be
part of Allowable 

                                       6.
<PAGE>
 
Expenses until Roberts has exercised its option pursuant to Section 4.2,
whereafter such costs shall be borne by Roberts.

                                   ARTICLE 4

                                  OPTION GRANT

     4.1  Option for Commercialization License.  Roberts shall have the option
to obtain an exclusive license, with the right to sublicense subject to
RiboGene's prior written approval, under RiboGene Technology and Collaboration
Technology in the Field to make, have made, use, import, offer for sale and sell
the Product in the Territory. The option shall be in effect in any particular
country of the Territory for a period beginning on the Effective Date and ending
sixty (60) days after first Regulatory Approval of the Product in that
particular country of the Territory ("Option Period").

     4.2  Option Exercise.  Roberts shall exercise the option by giving RiboGene
written notice prior to the expiration of the Option Period.

     4.3  Expiry of Option.  If the option granted under Section 4.1 expires
under the terms of this Agreement, Roberts shall transfer to RiboGene all
information, including, without limitation, data, reports and documentation
generated by Roberts in the course of the performance of the Development Program
and all rights of Roberts in and to such information.

                                   ARTICLE 5

                                COMMERCIAL TERMS

     5.1  License Fee.  Within [        *        ] after exercising the option
pursuant to Section 4.2 above, Roberts shall pay to RiboGene a license fee of
ten million dollars ($10,000,000) ("License Fee") as follows:

          (a)  [              *              ] of the License Fee, i.e. [    
         *
        ] if the option is exercised following FDA Regulatory Approval of the
Product for delayed onset emesis or for an indication which permits the
promotion of the Product for treatment of the symptoms of delayed onset emesis;

          (b)  [              *              ] of the License Fee, i.e. [ 
         *
        ] if the option is exercised following FDA Regulatory Approval of the
Product for an indication which does not permit the promotion of the Product for
the treatment of the symptoms of delayed onset emesis;

          (c)  [              *              ] of the License Fee, i.e. [
         *                       
        ] if the option is exercised following Regulatory Approval of the 
Product in Canada or Mexico;

          (d)  In the event of a partial payment of the License Fee pursuant to
subsections (b) through (c) above, Roberts shall make additional payments upon
the occurrence of any subsequent Regulatory Approvals for an indication which
permits the promotion of the 

                                       7.
<PAGE>
 
Product for the treatment of the symptoms of delayed onset emesis described in
subsections (a) through (c), up to and until such time as the full amount of the
License Fee has been paid;

          (e)  Notwithstanding the payment events described in subsections (b)
through (d) above and license fee payments made by Roberts thereunder, the
balance of the License Fee shall be due and payable (i) if gross sales generated
with the Product in the first year from the date of first commercial sale reach
or exceed [                      *                    ]; or (ii) if the
aggregate gross sales generated with the Product reach or exceed [
     *                                  ]

     5.2  Royalties.

          (a)  Royalty Rate.  Roberts shall pay to RiboGene royalties at a 
rate of [                       *                ] of Net Sales of the Product.

          (b)  Royalty Term.

               (i)    In any country where the manufacture, use or sale of the
Product is covered by a Collaboration Patent or RiboGene Patent, royalties shall
be payable in such country until the later of (i) [       *        ] from the 
first commercial sale of the Product in such country and (ii) the expiration of
the last to expire of such Collaboration Patent or RiboGene Patent.

               (ii)   In any country where the manufacture, use or sale of the
Product is not covered by a Collaboration Patent or RiboGene Patent, royalties
shall be payable in such country until the expiration of [        *        ] 
from the date of first commercial sale of the Product in such country.

          (c)  If, due to restrictions or prohibitions imposed by national or
international authority, including but not limited to restrictions on payments
of royalties from the Territory, Roberts is unable to make the payments of
royalties as aforesaid, the parties shall consult with a view to finding a
prompt and acceptable solution and Roberts shall not be relieved of the
obligation to make such payments and will from time to time deal with such
monies as RiboGene may lawfully direct.

          (d)  Any and all taxes payable in connection with the payments to be
made pursuant to this Section 5.2 shall be for the account of RiboGene. In the
event that Roberts shall be required to withhold or pay any taxes in the
Territory applicable to RiboGene with respect to any such payments, Roberts
shall promptly furnish RiboGene with the respective tax receipts, or other
evidence of payment.

          (e)  Upon request by RiboGene, Roberts shall file on behalf of
RiboGene any tax returns which the law of the Territory may require. Such tax
returns shall be filed in accordance with RiboGene's instructions and Roberts
shall pay such taxes on RiboGene's behalf, deducting the amounts of such tax
payments from the royalty payments due pursuant to this Section 5.2.

                                       8.
<PAGE>
 
          (f)  Roberts shall reasonably assist RiboGene in obtaining a tax
credit under the applicable taxation treaties and laws, including by providing
appropriate evidence of RiboGene's payment of the withholding tax.

     5.3  Due Diligence.

          (a)  Roberts undertakes to launch and sell the Product in each 
country of the Territory within [         *          ] from the date of 
Regulatory Approval, including pricing approval, where applicable, in such
country. Roberts shall market and promote the Product as it markets and promotes
its own products with similar sales potential.

          (b)  If Roberts has not launched the Product within the time period
required under subsection (a) above, Roberts' license obtained pursuant to the
exercise of the option under Section 4.2 shall be deemed to have expired in such
country, and such country shall be excluded from the Territory. Upon expiry of
the license, Roberts shall transfer to RiboGene all Regulatory Approvals in such
country, and information, including, without limitation, data, reports and
documentation generated by Roberts in the course of the performance of the
development of the Product for such country and all rights of Roberts in and to
such information.

     5.4  Territorial Limitation.  Roberts hereby undertakes to practice the
RiboGene Technology and Collaboration Technology licensed hereunder only within
the Territory. Roberts shall not sell or distribute the Product outside of the
Territory, and shall not sell or supply the Product to any third party of whom
it knows or has reason to believe that such third party sells or supplies the
Product to customers outside of the Territory.

                                   ARTICLE 6

                            PAYMENTS; RECORDS; AUDIT

     6.1  Royalty Payment and Reports.

          (a)  Royalty amounts payable to RiboGene under Section 5.2 shall be 
paid in U.S. Dollars within [         *          ] of the end of each calendar 
quarter. Each payment of royalties shall be accompanied by a statement of the
amount of Net Sales during such period, the amount of aggregate Net Sales to
date as of the end of such period, and the amount of royalties due on such Net
Sales.

          (b)  For the purpose of calculating royalties on Net Sales generated
in currencies other than U.S. dollars, such Net Sales shall be converted into
U.S. dollars at the rate of exchange as quoted in the Wall Street Journal on the
last business day of the relevant calendar quarter. All royalty payments owed
under this Agreement shall be made by means of wire transfer to RiboGene's
account in a bank in the United States to be designated by RiboGene.

     6.2  Records and Audit.

          (a)  During the term of this Agreement and for a period of 
[         *         ] thereafter, Roberts shall keep complete and accurate
records pertaining to the sale or other 

                                       9.
<PAGE>
 
disposition of the Product commercialized by it, in sufficient detail to permit
RiboGene to confirm the accuracy of all payments due hereunder.

          (b)  RiboGene shall have the right to cause an independent, certified
public accountant to audit such records to confirm Roberts's Net Sales and
royalty payments; provided, however, that such auditor shall not disclose
Roberts's confidential information to RiboGene, except to the extent such
disclosure is necessary to verify the amount of royalties due under this
Agreement.

          (c)  Such audits may be exercised once a year, within [     *      ]
after the royalty period to which such records relate, upon notice to Roberts
and during normal business hours.

          (d)  RiboGene shall bear the full cost of such audit unless such 
audit discloses a variance of more than [            *            ] from the 
amount of the Net Sales or royalties previously paid.  In such case, Roberts 
shall bear the full cost of such audit.  The terms of this Section 6.2 shall 
survive any termination or expiration of this Agreement for a period of 
[         *         ]

          (e)  Overdue Payments.  If RiboGene does not receive payment of any
sum payable under this Agreement on the date it is due, simple interest shall
thereafter accrue on the sum due to RiboGene until the date of payment at the
per annum rate of [       *       ]

                                   ARTICLE 7

                         PATENT PROSECUTION AND DEFENSE

     7.1  Patent Prosecution and Maintenance.

          (a)  RiboGene shall maintain the RiboGene Patents during the term of
this Agreement. The costs of such maintenance shall be part of Allowable
Expenses until Roberts has exercised its option pursuant to Section 4.2,
whereafter such costs shall be borne by Roberts.

          (b)  Roberts shall be responsible for filing and prosecuting
applications for Collaboration Patents and for maintaining Collaboration Patents
owned solely by either party or jointly by the parties in the Territory. Roberts
shall consult with RiboGene as to the selection of countries in which to file
applications for such Collaboration Patents. Roberts shall be responsible for
bearing the cost of filing and prosecuting applications for Collaboration
Patents and of maintaining Collaboration Patents in the Territory. In the event
that Roberts decides not to proceed with prosecuting an application for a
Collaboration Patent, it shall give RiboGene [         *          ] notice 
before any relevant deadline, and RiboGene shall have the right to pursue, at
its own expense, prosecution of such patent application or maintenance of such
patent, and such patent shall be excluded from the licenses granted herein or 
in the License Agreement.

          (c)  Each party agrees to cooperate with the other and take all
reasonable additional actions and execute such agreements, instruments, and
documents as may be 

                                      10.
<PAGE>
 
reasonably required to prosecute patent applications as provided in this
section, and to perfect the other's ownership interest in Collaboration Patents
as allocated in Article 3, including, without limitation, the execution of
necessary and appropriate instruments of assignment.

     7.2  Infringement of Patents by Third Parties.

          (a)  Notice.  Each party shall promptly notify the other in writing of
any alleged or threatened infringement of RiboGene Patents, Roberts Patents, or
Collaboration Patents which may adversely impact the rights of the parties
hereunder.

          (b)  Roberts Patents and RiboGene Patents.

                (i)    The party which is the holder of Roberts Patents or
RiboGene Patents, respectively, shall have the right, but not the obligation, to
bring an appropriate action against any person or entity directly or
contributorily infringing its patents. If the patent holder brings an action
against an alleged infringer, the other party shall cooperate reasonably with
the patent holder in any such efforts.

                (ii)   Any recovery obtained by the patent holder as a result of
such action, whether obtained by settlement or otherwise, shall be disbursed as
follows: first, each party shall be reimbursed for any reasonable expenses
incurred in bringing or assisting in such action (including counsel fees). If
the infringement was made by a third party product which competed with the
Product in the Territory, the remaining proceeds shall be added to Net Sales. In
the event of any other kind of infringement, the remaining proceeds shall
retained by the patent holder.

                (iii)  No settlement, compromise or other disposition of any
such action which compromises a party's rights under this Agreement shall be
entered into without such party's prior consent, which shall not be unreasonably
withheld.

          (c)  Collaboration Patents.

                (i)    If a Collaboration Patent is infringed in the Territory,
Roberts shall have the right to bring, at its own expense, an appropriate action
against any person or entity directly or contributorily infringing such
Collaboration Patent. In such event, RiboGene shall cooperate reasonably with
Roberts in any such action, including if required to bring such action, the
furnishing of a power of attorney.

                (ii)   In the event Roberts fails to institute an infringement
suit or take other reasonable action to protect the relevant Collaboration
Patent, RiboGene shall have the right, upon [      *      ] of notification of
Roberts, to institute such suit or take other appropriate action at its own
expense in its own name, the joint owners' name, or both. In such event, Roberts
hereby agrees to cooperate reasonably with RiboGene in any such effort,
including if required to bring such action, the furnishing of a power of
attorney.

                (iii)  Regardless of which party brings the action, any recovery
obtained by settlement or otherwise shall be disbursed as follows: the party
bringing such action shall first ensure that any reasonable expenses incurred in
assisting in such action (including counsel fees) 

                                      11.
<PAGE>
 
by both parties are reimbursed. Thereafter, the party bringing such action shall
ensure that the net recovery shall be added to Net Sales.

     7.3  Infringement of Third Party Rights.

                (i)    Joint Strategy. In the event that the Product developed,
manufactured or sold hereunder becomes the subject of a claim for patent,
copyright or other proprietary right infringement in the Territory ("Product
Infringement Claim"), and irrespective of whether Roberts or RiboGene is charged
with said infringement, and the venue of such claim, the parties shall promptly
confer to discuss the claim. The parties shall agree on how to best defend the
Product Infringement Claim and shall designate the party who shall have primary
responsibility to conduct the defense of any Product Infringement Claim in the
Territory.

                (ii)   Defense. The party with primary responsibility for the
defense of a Product Infringement Claim shall keep the other party informed on
the progress and shall provide it with copies of all filings made or received in
connection with such claim. The other party shall have the right to participate
in any proceedings and to be represented by counsel of its own choice. The costs
of such defense shall be shared between the parties. Each party shall reasonably
cooperate with the party conducting the defense of the Product Infringement
Claim, including if required to conduct such defense, furnishing a power of
attorney. Neither party shall enter into any settlement that affects the other
party's rights or interests without such other party's written consent, which
consent shall not be unreasonably withheld.

     7.4  Patent Marking.  Roberts shall mark, if necessary, all the Product
manufactured, used or sold under the terms of this Agreement, or its containers,
in accordance with the applicable patent marking laws, as required.

                                   ARTICLE 8

                             PUBLICATION; PUBLICITY

     8.1  Publication.

          (a)  Review and Approval. Each party to this Agreement recognizes that
the publication of papers, including oral presentations and abstracts, regarding
the Collaboration Know-How and the Collaboration Patents, subject to reasonable
controls to protect Confidential Information, will be beneficial to both
parties. However, each party shall have the right to review and approve any
paper proposed for publication by the other party, including oral presentations
and abstracts, which utilizes data generated from the Development Program and/or
includes Collaboration Know-How or Confidential Information of the reviewing
party.

          (b)  Review and Approval Process.  At least [     *      ] before any
such paper is presented or submitted for publication, the party proposing
publication shall deliver a complete copy to the other party. The receiving
party shall review any such paper and give its comments to the publishing party
within [      *      ] of the delivery of such paper to the receiving party. 
With respect to oral presentation materials and abstracts, the parties shall
make reasonable efforts to expedite review of such materials and abstracts, and
shall return such items 

                                      12.
<PAGE>
 
as soon as practicable to the publishing party with appropriate comments, if
any, but in no event later than [      *      ] from the delivery date thereof 
to the receiving party. The publishing party shall comply with the other party's
request to delete references to such other party's Confidential Information in
any such paper and agrees to withhold publication of same in order to permit the
parties to obtain patent protection, if either of the parties deem it necessary,
in accordance with the terms of this Agreement.

     8.2  Publicity.  Except as otherwise provided herein or required by law, no
party shall originate any publication, news release or other public
announcement, written or oral, whether in the public press, or stockholders'
reports, or otherwise, relating to the existence of or the performance under
this Agreement, without the prior written approval of the other party, which
approval shall not be unreasonably withheld, [                          *       
        ]

     8.3  Press Release.  Notwithstanding any provision of this Agreement to the
contrary, promptly after the date hereof, each party may issue a press release
substantially in the form as agreed to by the parties.

                                   ARTICLE 9

                         REPRESENTATIONS AND WARRANTIES

     9.1  Corporate Power, Due Authorization, Binding Agreement. Each party
hereby represents and warrants:

          (a)  That it is duly organized and validly existing under the laws of
the state or country of its incorporation and has full corporate power and
authority to enter into this Agreement and to carry out the provisions hereof;

          (b)  That it is duly authorized to execute and deliver this Agreement
and to perform its obligations hereunder;

          (c)  That this Agreement is a legal and valid obligation binding upon
it and is enforceable in accordance with its terms, and that the execution,
delivery and performance of this Agreement by such party does not conflict with
any agreement, instrument or understanding, oral or written, to which it is a
party or by which it may be bound, nor violate any law or regulation of any
court, governmental body or administrative or other agency having authority over
it.

     9.2  Intellectual Property. Each party has the full right to grant the
licenses granted by it under this Agreement and is not aware, to the best of its
knowledge, of any claims by third parties to a conflicting ownership interest in
its solely-owned Patents.

     9.3  RiboGene Disclaimer.  THE RIBOGENE TECHNOLOGY AND COLLABORATION
TECHNOLOGY LICENSED HEREUNDER IS PROVIDED "AS IS" AND RIBOGENE EXPRESSLY
DISCLAIMS ANY AND ALL WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
WITHOUT LIMITATION THE WARRANTIES OF DESIGN, MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE, NONINFRINGEMENT OF THE INTELLECTUAL PROPERTY RIGHTS OF 

                                      13.
<PAGE>
 
THIRD PARTIES OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICES, IN
ALL CASES WITH RESPECT THERETO.

                                  ARTICLE 10

                                INDEMNIFICATION

     10.1  Indemnification by RiboGene.  RiboGene shall indemnify Roberts, its
Affiliates, and all their officers, directors, employees and agents, for any
reasonable out-of-pocket costs and expenses (including court and arbitration
costs, witness fees and reasonable attorneys' fees), non-appealed or non-
appealable judicial or arbitration damage awards, and settlement payments,
payable or owed by Roberts in connection with any demands, law suits and other
legal actions of third parties arising from (i) the performance or breach of
this Agreement by RiboGene, and (ii) any negligent actions or willful misconduct
by RiboGene, its Affiliates, agents or sublicensees.

     10.2  Indemnification Undertaking by Roberts. Roberts shall indemnify
RiboGene, its Affiliates and sublicensees, and all their officers, directors,
employees and agents, for any reasonable out-of-pocket costs and expenses
(including court and arbitration costs and reasonable attorneys' fees), non-
appealed or non-appealable judicial or arbitration damage awards, and settlement
payments agreed with the third party claimants payable or owed by RiboGene in
connection with any demands, law suits and other legal actions of third parties
arising from (i) the performance or breach of this Agreement by Roberts, (ii)
any negligent actions or willful misconduct by Roberts, its Affiliates, or
agents, and (iii) the possession, manufacture, use, marketing, promotion,
distribution, sale or administration of the Product.

     10.3  Conditions and Limitations of Indemnification Obligation.

           (a)  In order to maintain the right to be indemnified by the other
party ("Indemnitor") for any demands, law suits and other legal actions of third
parties ("Third Party Claims") described in Sections 10.1 and 10.2 above, the
party claiming indemnification ("Indemnitee") must:

                (i)    notify the Indemnitor promptly after learning of a Third
Party Claim;

                (ii)   allow the Indemnitor to manage and control (by way of
intervention or otherwise) the defense and/or settlement of the Third Party
Claim against the Indemnitee;

                (iii)  cooperate with the Indemnitor in the defense or the
settlement negotiations of any Third Party Claims for which indemnification is
sought, as reasonable required by the Indemnitor;

                (iv)   abstain from making any statements or taking any actions
which damage the defense against a Third Party Claim (including, without
limitation, any statements against the interest of the Indemnitee or admissions
of causation or guilt);

                                      14.
<PAGE>
 
           (b)  The Indemnitor shall not agree to any settlement that adversely
affects the Indemnitee's rights or interest without the Indemnitee's prior
written approval (which approval shall not be unreasonably withheld).

           (c)  The Indemnitor shall have no obligation to indemnify the
Indemnitee to the extent that a Third Party Claim results from the negligence or
willful misconduct of the Indemnitee.

                                  ARTICLE 11

                                CONFIDENTIALITY

     11.1  Disclosure of Confidential Information.  Confidential Information
disclosed by one party to the other pursuant to and during the term of this
Agreement shall be subject to the confidentiality obligations set forth below:

           (a)  if disclosed in writing and marked "confidential" or
"proprietary" by the disclosing party prior to or at the time of the disclosure
thereof, or if it would be apparent to a reasonable person, familiar with the
disclosing party's business and the industry, that such information is of a
confidential or proprietary nature; and

           (b)  if [         *          ] after disclosure of Confidential
Information, the disclosing party informs the receiving party in writing of the
confidential nature of the disclosed information, describing such information
and referencing the place and date of the oral, visual or written disclosure and
the names of the employees or officers of the receiving party to whom such
disclosure was made.

     11.2  Confidentiality and Non-Use.  Except to the extent expressly
authorized by this Agreement or unless otherwise agreed in writing by the
parties, each party agrees that, for the combined term of this Agreement and the
Development Agreement, and for [      *      ] thereafter, it shall keep 
confidential and shall not publish or otherwise disclose and shall not use for
any purpose other than as provided for in this Agreement any Confidential
Information, unless the receiving party can demonstrate by competent proof that
such Confidential Information:

           (a)  was already known to the receiving party, other than under an
obligation of confidentiality, at the time of disclosure by the other party;

           (b)  was generally available to the public or otherwise part of the
public domain at the time of its disclosure to the receiving party;

           (c)  became generally available to the public or otherwise part of
the public domain after it disclosure and other than through any act or omission
of the receiving party in breach of such Agreements;

           (d)  was disclosed to the receiving party, other than under an
obligation of confidentiality to a third party, by a third party who had no
obligation to the disclosing party not to disclose such information to others;
or

                                      15.
<PAGE>
 
           (e)  was independently discovered or developed by the receiving party
without the use of Confidential Information belonging to the disclosing party.

     11.3  Authorized Disclosure.

           (a)  Each party may disclose Confidential Information belonging to
the other party to Affiliates and sublicensees who agree to be bound by similar
terms of confidentiality. In addition, each party may disclose Confidential
Information of the other party to the extent such disclosure is reasonably
necessary to: (i) comply with applicable securities laws and regulations and
other applicable governmental regulations, (ii) file or prosecute patents
relating to Collaboration Technology, (iii) prosecute or defend litigation, (iv)
file applications for Regulatory Approvals for the Product, and (vi) conduct 
pre-clinical or clinical trials with the Product.

           (b)  Notwithstanding the foregoing, in the event a party is required
to make a disclosure of the other party's Confidential Information pursuant to
subsection (a) above, it will, except where impracticable, give reasonable
advance notice to the other party of such disclosure and use best efforts to
secure confidential treatment of such information. In any event, the parties
agree to take all reasonable action to avoid disclosure of Confidential
Information hereunder.

                                  ARTICLE 12

                           IMPORT AND EXPORT CONTROLS

     12.1  United States Laws. The parties understand and acknowledge that each
of them is subject to regulation by agencies of the U.S. government, including
the U.S. Department of Commerce, which prohibit export, re-export or diversion
of the Product and technology to certain countries. Any and all obligations of
Roberts or RiboGene to provide access to or license any technology pursuant to
this Agreement, as well as any technical assistance shall be subject in all
respects to such United States laws and regulations as shall from time to time
govern the license and delivery of technology and the Product abroad by persons
subject to the jurisdiction of the United States, including the Export
Administration Act of 1979, as amended, any successor or interim controlling
legislation, and the Export Administration Regulations issued by the Department
of Commerce, International Trade Administration, Bureau of Export

                                      16.
<PAGE>
 
Administration. Both parties also agree to comply with the requirements of the
U.S. Foreign Corrupt Practices Act (the "Act") and shall refrain from making any
payments to third parties which would cause Roberts or RiboGene to violate the
Act.

     12.2  Non-United States Laws.  Roberts and RiboGene shall each provide the
other party with such reasonable assistance as may be required for the party
requesting such assistance to comply with all non-United States laws,
ordinances, rules, regulations and the like of all governmental units or
agencies having jurisdiction pertaining to this Agreement, including without
limitation, obtaining all import, export and other permits, certificates,
licenses or the like required by such non-United States laws, ordinances, rules,
regulations and the like, necessary to permit the parties to perform hereunder
and to exercise their respective rights hereunder.

                                  ARTICLE 13

                              TERM AND TERMINATION

     13.1  Term. Except as provided under Section 13.2 below, the term of this
Agreement shall commence upon the Effective Date and shall expire on the
expiration date of the last to expire royalty obligation.

     13.2  Termination on Material Breach. If either party materially breaches
the Agreement, including without limitation its due diligence obligations under
Section 2.2(b) and 5.3, and the breaching party has not cured the breach or
initiated good faith efforts to cure such breach to the reasonable satisfaction
of the non-breaching party within sixty (60) days of notice of breach from the
non-breaching party, the non-breaching party may terminate this Agreement upon
expiration of such sixty (60)-day period.

     13.3  Licenses upon Expiration or Termination.

           (a)  Upon expiration or termination of this Agreement, Roberts shall
have a fully paid, nonexclusive license under RiboGene Technology and
Collaboration Technology in the Field to make, have made, use, import, offer for
sale and sell the Product in the Territory.

           (b)  Notwithstanding subsection (a) above, if this Agreement is
terminated by RiboGene based on a material breach by Roberts, then Roberts'
license rights shall terminate and RiboGene shall have a perpetual, paid-up,
worldwide license under Roberts Technology and Roberts-owned or jointly owned
Collaboration Technology to make, have made, use, import, offer for sale and
sell the Product.

           (c)  If this Agreement is terminated by Roberts due to a failure by
RiboGene to pay for the performance of the Development Program conducted under
this Agreement, Roberts shall have an exclusive license under RiboGene
Technology and Collaboration Technology in the Field to make, have made, use,
import, offer for sale and sell the Product in the Territory, subject only to
the obligation to pay the License Fee (less any amounts of the Development Funds
owed but not paid by RiboGene to Roberts hereunder) and royalties as provided in
Section 5.2.

                                      17.
<PAGE>
 
     13.4  Surviving Rights and Obligations.  Termination of this Agreement, for
whatever reason, shall not affect any rights or obligations of either party
which are intended by the parties to survive termination.

     13.5  Accrued Rights.  The termination, relinquishment or expiration of the
Agreement for any reason shall be without prejudice to any rights which shall
have accrued to the benefit of either party prior to such termination,
relinquishment or expiration, including any damages arising from any breach
hereunder.

                                  ARTICLE 14

                                 MISCELLANEOUS

     14.1  Waiver. No waiver by either party hereto of any breach or default of
any of the covenants or agreements herein set forth shall be deemed a waiver as
to any subsequent or similar breach or default.

     14.2  Assignment. This Agreement shall be binding upon and inure to the
benefit of the parties hereto and their permitted successors and assigns;
provided, however, that neither party shall assign any of its rights and
obligations hereunder without the prior written consent of the other; except
that RiboGene may assign this Agreement incident to the merger, consolidations,
reorganization, or acquisition of stock or assets affecting substantially all of
the assets or actual voting control of RiboGene.

     14.3  Notices. Any notice or other communication required or permitted to
be given to either party hereto shall be in writing and shall be deemed to have
been properly given and to be effective on the date of delivery if delivered in
person or by facsimile or five (5) days after mailing by registered or certified
mail, postage paid, to the other party at the following address:

     In the case of RiboGene: RiboGene, Inc.
                              26118 Research Road
                              Hayward, CA 94545
                              Fax: (510) 293-2596
                              Attention: President

     with a copy to:          Cooley Godward LLP
                              Five Palo Alto Square
                              Palo Alto, CA 94306
                              Fax: (650) 857-0663
                              Attention: Brian C. Cunningham, Esq.

     In the case of Roberts:  Roberts Pharmaceutical Corporation
                              Meridian Center II
                              4 Industrial Way West
                              Eatontown, New Jersey 07724
                              Fax: (732) 398-1014
                              Attention: A. A. Rascio, VP and General Counsel

                                      18.
<PAGE>
 
Either party may change its address for communications by a notice to the other
party in accordance with this section.

     14.4  Headings.  The headings of the several sections are inserted for
convenience of reference only and are not intended to be a part of or to affect
the meaning or interpretation of this Agreement.

     14.5  Amendment.  No amendment or modification hereof shall be valid or
binding upon the parties unless made in writing and signed by both parties.

     14.6  Choice of Law, Jurisdiction and Venue.

           (a)  This Agreement and its terms and conditions shall be governed
exclusively by and construed according to the laws of California, excluding its
choice of law provisions and also excluding the United Nations Convention on
Contracts for the International Sale of Goods.

           (b)  All disputes which may arise between the parties hereto in
relation to the interpretation or administration of this Agreement shall be
first referred to the Steering Committee for resolution. Any disputes which the
Steering Committee is unable to resolve with a reasonable period of time shall
be resolved by the agreement of the Chief Executive Officers of the respective
parties or their delegates. Any disputes which cannot be resolved in this manner
shall be finally resolved in the courts with jurisdiction and venue at the
domicile of the defendant.

     14.7  Force Majeure.  Any delays in performance by any party under this
Agreement  shall not be considered a breach of this Agreement if and to the
extent caused by occurrences beyond the reasonable control of the party
affected, including but not limited to acts of God, embargoes, governmental
restrictions, strikes or other concerted acts of workers, fire, flood,
explosion, riots, wars, civil disorder, rebellion or sabotage.  The party
suffering such occurrence shall immediately notify the other party as soon as
practicable and any time for performance hereunder shall be extended by the
actual time of delay caused by the occurrence.

     14.8  Independent Contractors.  In making and performing this Agreement,
Roberts and RiboGene act and shall act at all times as independent contractors
and nothing contained in this Agreement shall be construed or implied to create
an agency, partnership or employer and employee relationship between RiboGene
and Roberts. At no time shall one party make commitments or incur any charges or
expenses for or in the name of the other party.

     14.9  Severability.  If any term, condition or provision of this Agreement
is held to be unenforceable for any reason, it shall, if possible, be
interpreted rather than voided, in order to achieve the intent of the parties to
this Agreement to the extent possible. In any event, all other terms, conditions
and provisions of this Agreement shall be deemed valid and enforceable to the
full extent.

     14.10  Cumulative Rights.  The rights, powers and remedies hereunder shall
be in addition to, and not in limitation of, all rights, powers and remedies
provided at law or in equity, or under any other agreement between the parties.
All of such rights, powers and remedies shall be cumulative, and may be
exercised successively or cumulatively.

                                      19.
<PAGE>
 
     14.11  Counterparts.  This Agreement may be executed in two or more
counterparts, each of which shall be an original and all of which shall
constitute together the same document.

     14.12  Entire Agreement.  This Agreement and any and all Schedules and
Appendices referred to herein embodies the entire understanding of the parties
with respect to the subject matter hereof and shall supersede all previous
communications, representations or understandings, either oral or written,
between the parties relating to the subject matter hereof.

                                      20.
<PAGE>
 
     In Witness Whereof, both Roberts and RiboGene have executed this Agreement,
in duplicate originals, by their respective officers hereunto duly authorized,
as of the day and year hereinabove written.

RiboGene, Inc.                          Roberts Pharmaceutical Corporation


By: /s/ Timothy E. Morris               By: /s/ Anthony A. Rascio
   ------------------------                -----------------------------

Name:   TIMOTHY E. MORRIS               Name:   ANTHONY A. RASCIO
Title:  Vice President Finance &        Title:  Vice President
        Administration and
        Chief Financial Officer

                                      21.
<PAGE>
 
                                   Exhibit A

                               Allowable Expenses

[

                                       *

                                        

                                                            ]

[ ] Estimated costs for patent and trademark prosecution, consisting of
approximately [
                           *                           ] including the estimated
cost of

[                 *                             ]

[  ] Estimated patent and trademark maintenance costs (subject to increases due
to litigation or other unforeseen circumstances).

[   ] These expenses shall [             *               ] once the Product, [
               *                           ]


                                      1.
<PAGE>
 
                                   Exhibit B

                                RiboGene Patents

[

                                       *

                                                            ]


                                        

                                      2.