<PAGE>

                                                                   EXHIBIT 10.21

                                    FORM OF
                           SCIENTIFIC ADVISORY BOARD
                                   AGREEMENT

This Scientific Advisory Board Agreement (this "Agreement") is entered into
effective as of __________, 2000, by and between Keryx Biopharmaceuticals, Inc.,
a Delaware corporation, with a mailing address at 216 Jaffa Road, Jerusalem
94383 Israel ("the Corporation") and Dr. James Broach, with a mailing address of
_____________________________________________________ (the "Advisor").

1.  The Scientific Advisory Board.  The Advisor agrees to perform scientific
    -----------------------------
    advisory services for the Corporation, devoting such time, attention,
    knowledge and skill as reasonably requested by the Corporation's Board of
    Directors or their designee, and as the interests, needs, business or
    opportunities of the Corporation shall require, at such time and place as
    the Corporation's Board of Directors or their designee shall reasonably
    request (the "Services"), for a period of three (3) years, unless earlier
    terminated in accordance with Section 3 (the "Services Period"). The
    Services Period may be extended for additional one (1) year periods upon the
    written agreement of the parties hereto.

2.  Compensation for Service Rendered.
   ---------------------------------

   (a) Per Diem Fee. For providing the services, the Corporation shall pay the
   Advisor a per diem fee of $2,500.

   (b) Stock Options. Within twenty one (21) days of the execution of this
   Agreement by the Advisor, the Board of Directors of the Corporation or a duly
   formed committee thereof shall issue to the Advisor an option to purchase one
   thousand (1,000) shares of the Corporation's Common Stock at a price equal to
   offering price at the initial public offering of the Corporation's Common
   Stock. Of these, five hundred (500) shall be deemed vested as of the date of
   grant and the balance shall vest in two equal annual installments, with the
   first occurring on the first anniversary of the date of the grant, provided
   that on the each vesting date the Advisor is still being retained pursuant to
   this or a similar agreement with the Corporation. Such options shall be
   deemed to have been granted pursuant to, and shall be governed by, the
   Corporation's stock option program applicable to consultants to the
   Corporation. If this Agreement is terminated by the Corporation or the
   Advisor for any reason prior to the expiration of its term, the Corporation
   shall have the right to repurchase the vested portion of such options (or the
   shares resulting from the exercise of such options if such exercise has
   occurred) at the then-current fair market value of such shares or options, as
   reasonably determined by the Board of Directors of the Corporation. Such
   right shall be exercised by the Corporation and payment made, if at all,
   within ninety (90) days after the effective date of such termination.

3.  Termination.  The obligation of the Advisor to perform the Services may be
    -----------
    terminated by the Corporation during the Services Period with respect to the
    Advisor for any reason, with or without cause, upon the agreement of a
    majority of the Corporation's Board of Directors.
<PAGE>

    The Advisor may voluntarily terminate his obligation to perform the Services
    for the Corporation at any time and for any reason (a "Voluntary
    Termination"). However, the Advisor agrees to provide thirty (30) days
    advance notice prior to the effective date of termination.

4.  Agreement Not to Compete.  During the Services Period and for twelve (12)
    ------------------------
    months thereafter, the Advisor agrees that he will not affiliate in any
    material role, including affiliation as an employee, consultant agent, or
    contractor, with any business enterprise which is in direct conflict or
    competition with the Corporation in the modulation of protein kinases to
    discover or develop pharmaceutical products (the "Field") nor will he found,
    promote or become a shareholder, partner, or owner in any other enterprise
    which competes with the Corporation in the Field other than as stockholder
    of up to five percent (5%) of the outstanding stock of any publicly traded
    corporation. Notwithstanding the foregoing, nothing in this Section shall
    prevent or inhibit the Advisor from conducting academic research in subjects
    related to the Field provided that the Advisor complies with the
    confidentiality obligations set forth in Section 7, below.

5.  Noninterference With Employees.  The Advisor agrees that for a period of
    ------------------------------
    twelve (12) months following the termination of the performance of the
    Services for the Corporation by the Advisor, the Advisor will not interfere
    with or attempt to impair the relationship between the Corporation and any
    of its employees, consultants, and advisors, nor will the Advisor attempt to
    solicit, to entice, to hire, or otherwise to induce any employee,
    consultant, or advisor of the Corporation to terminate association with the
    Corporation.

6.  Remedies in the Event of Breach. The Corporation and the Advisor understand
    -------------------------------
    and agree that any breach or threatened breach by the Corporation or the
    Advisor of any of the provisions set forth in Section 4 and 5, cannot be
    remedied solely by the recovery of damages, and in the event of any such
    breach or threatened breach, the Corporation and the Advisor, as the case
    may be, shall be entitled to seek injunctive relief, restraining the Advisor
    or the Corporation, as the case may be, and any business, firm, corporation,
    individual, or other entity participating in such breach or attempted breach
    from engaging in any activity which would constitute a breach. The
    Corporation and the Advisor further agree that any dispute arising under the
    terms of this Agreement, other than a dispute that would be remedied by
    injunctive relief, shall be decided in accordance with the then current
    rules of the American Arbitration Association, and any arbitration award may
    be entered in a court of competent jurisdiction and enforced as a judgment
    thereof. Any such arbitration shall be heard at an appropriate location in
    the City of New York. Nothing herein, however, shall be construed as
    prohibiting the Corporation or the Advisor from pursuing, in conjunction
    with an injunction or otherwise, any other remedies available in equity for
    any such breach or threatened breach, including the recovery of damages.

7.  Non-Disclosure and Developments.
    -------------------------------

    (a)  Advisor shall not at any time, whether during or after the termination
      of this Agreement, disclose to any person or entity any of the trade
      secrets or confidential information concerning the organization, business
      or finances of
<PAGE>

      the Corporation or of any third party which the Corporation is under an
      obligation to keep confidential (including but not limited to trade
      secrets or confidential information respecting inventions, patent
      applications, products, designs, methods, know-how, techniques systems,
      processes, software programs, works of authorship customer lists,
      projects, plans and proposals), except as may be required in the ordinary
      course of performing the Advisor's duties on behalf of the Corporation,
      and the Advisor shall keep secret all matters entrusted to the Advisor and
      shall not use or attempt to use any such information in any manner which
      may injure or cause loss or may be calculated to injure or cause loss
      whether directly to the Corporation.

      Further, the Advisor agrees that during the term of this Agreement, the
      Advisor shall not make, use or permit to be used any notes, memoranda,
      reports, lists, records, drawings, sketches, specifications, software
      programs, data, documentation, or other materials of any nature arising
      out of, or in connection with, this Agreement otherwise than for the
      benefit of the Corporation. The Advisor further agrees that he shall not,
      after the termination of this Agreement, use or permit to be used any such
      notes, memoranda, reports, lists, records, drawings, sketches,
      specifications, software programs, data, documentation or other materials,
      it is agreed that all of the foregoing shall be and remain the sole and
      exclusive property of the Corporation and that immediately upon the
      termination of this Agreement, the Advisor shall deliver all of the
      foregoing, and all copies thereof in his possession or under his control,
      to the Corporation, at its main office.

      Notwithstanding the foregoing, the Advisor may disclose information (i)
      received from a third party (other than the Corporation) which is not
      subject to any confidentiality restriction, (ii) required by law to be
      disclosed, including, by way of example and not limitation, pursuant to a
      subpoena or other discovery device or a court order, or (iii) already in
      the public domain.

    (b)  If at any time or times during the Advisor's work for the Corporation,
      the Advisor (either alone or with others) makes, conceives, creates,
      discovers, invents, or reduces to practice any invention, modification,
      discovery, design, development, improvement, process, software program,
      work of authorship, documentation, formula, data, technique, know-how,
      trade secret or intellectual property right whatsoever or any interest
      therein (whether or not patentable or registerable under copyright,
      trademark or similar statuses (herein called "Developments") that (i)
      relates to the business of the Corporation or any of the products or
      services being developed, manufactured or sold by the Corporation or which
      may be used in relation therewith, (ii) results from tasks assigned the
      Advisor by the Corporation or (iii) results from the use of premises or
      personal property (whether tangible or intangible) owned, leased or
      contracted for by the Corporation, the Advisor shall promptly disclose to
      the Corporation (or any persons designated by it) each such Development.
      The Advisor hereby assigns any rights (including, but not limited to, any
      copyrights and trademarks) the Advisor may have or acquire in the
      Developments and benefits and/or rights resulting therefrom to the
      Corporation and its assigns without further compensation, as may be
      necessary to ensure the Corporation's ownership of such Developments, and
<PAGE>

      shall communicate, without cost or delay, and without disclosing to others
      the same, all available information relating thereto (with all necessary
      plans and models) to the Corporation.

      The Advisor shall during this Agreement, and at any time thereafter, at
      the request and cost of the Corporation, promptly sign, execute make and
      do all such deeds, documents, acts and things as the Corporation and its
      duly authorized agents may reasonably require (iv) to apply for, obtain
      register and vest in the name of the Corporation alone (unless the
      Corporation otherwise directs) letters patents, copyrights, trademarks or
      other analogous protection relating to the Developments in any country
      throughout the world and when so obtained or vested to renew and restore
      the same; and (v) to defend any judicial opposition or other proceedings
      in respect of such applications and any judicial, opposition or other
      proceedings or applications for revocation of such letters patent,
      copyright, trademark or other analogous protection.

      In the event the Corporation is unable, after reasonable effort, to secure
      the Advisor's signature on any application for letters patent, copyright
      or trademark registration or other documents regarding any legal
      protection relating to the Developments, whether because of the Advisor's
      physical or mental incapacity or for any other reason whatsoever, the
      Advisor hereby irrevocably designated and appoints the Corporation and its
      duly authorized officers and agents as his agent and attorney-in-fact, to
      act for and in the Advisor's behalf and stead to execute and file any such
      application or applications or other documents and to do all other
      lawfully permitted acts to further the prosecution and issuance of letters
      patent, copyright or trademarks registrations, or any other legal
      protection thereon with the same legal force and effect as if executed by
      the Advisor.

      It is understood that any intellectual property or Developments which the
      Advisor has developed, or in the future may develop, which is or will be,
      owned or licensed by his current employer or any other permitted employer
      of his (other than the Corporation) shall not be subject to this
      Agreement. It is further understood that in the event that there is
      reasonable uncertainty whether certain information which Advisor has
      obtained is required to be disclosed to the Corporation pursuant to this
      Subsection (b), Advisor shall have a reasonable amount of time to consult
      with his current employer or any other permitted employer of Advisor to
      whom such information may belong before determining whether or not to
      disclose such information to the Corporation.

    (c)  Advisor agrees that any breach of this Agreement by Advisor will cause
      irreparable damage to the Corporation and that in the event of such breach
      the Corporation shall have, in addition to any and all remedies of law,
      the right to seek an injunction, specific performance or other equitable
      relief to prevent the violation of the Advisor's obligations hereunder.

    (d)  The Advisor represents that the Developments identified in the pages,
      if any, attached hereto as Exhibit A comprise all the unpatented
      Developments and all copyrightable but unregistered Developments which the
      Advisor had
<PAGE>

      made, conceived or created prior to his performance of Services for the
      Corporation, all of which Developments are excluded from this Agreement.
      The Advisor understands that it is only necessary to list the title and
      purpose of such Developments but not details thereof.

      The Advisor further represents that his performance of all of the terms of
      this Agreement does not and will not breach any agreement to keep in
      confidence proprietary information acquired by him in confidence or in
      trust prior to his obligation to perform Services for the Corporation. The
      Advisor has not entered into, and agrees that he shall not enter into, any
      agreement either written or oral in conflict herewith.

8.  Independent Contractor.
    -----------------------

    (a)  The Advisor agrees that in rendering the Services hereunder, the
      Advisor and any person employed by, or subcontracting with, the Advisor to
      perform the Services, shall act (and be considered for all purposes) as an
      independent contractor of the Corporation, and not as an employee or agent
      of the Corporation. In his capacity as an independent contractor, the
      Advisor agrees and represents, and the Corporation agrees, that the
      Advisor: (i) has the right to control and direct the means and methods of
      performing the Services by himself, his employees, and his subcontractors;
      (ii) will provide supervision of all his employees and subcontractors
      assigned to perform the Services; (iii) will utilize and pay for the
      Advisor's, and his employees' and subcontractors' own tools and equipment,
      and will reimburse the Corporation for the use of the Corporation's
      equipment and administrative services, facilities and other consideration
      provided by the Corporation; (iv) shall receive compensation from the
      Corporation only as set forth herein and will not participate in benefits
      of any sort which the Corporation offers to its subcontractors; (v) shall,
      to the extent practical, keep his equipment, materials, drawings, and the
      like separate from any Corporation property, and will not remove any
      Corporation property from the premises without prior written approval by
      an authorized representative of the Corporation; (vi) maintain a place of
      business at a location other than the premises of the Corporation; (vii)
      will not require that he, his employees, or his subcontractors be trained
      by the Corporation in the professional skills necessary to perform the
      Services, though the Corporation may give general directions and
      orientation instructions; (viii) shall be fully liable for the grossly
      negligent or willful injurious acts or omissions of himself, his
      employees, or his subcontractors, causing harm to persons or property, but
      shall not be liable for consequential damages due to defects in
      performance; and (ix) shall deal with the Advisor's employees' or
      subcontractors' trade or union representatives, negotiate all employee and
      subcontractor disputes and terminate or change all employee or
      subcontractor assignments as necessary.

    (b)  Inasmuch as the Advisor and the Corporation are contractors independent
      of one another, neither has the authority to bind the other to any third
      person or otherwise to act in any way as the representative of the other,
      unless otherwise expressly agreed to in writing signed by both parties
      hereto. The Advisor agrees not to represent himself as the Corporation's
      agent for any
<PAGE>

      purpose to any party unless specifically authorized, in advance and in
      writing, to do so, and then only for the limited purposes(s) stated in
      such authorization. This prohibition includes the use by the Advisor of
      the Corporation's stationery and forms; all contracts with third parties
      shall be made on the Advisor's own stationery and in the Advisor's own
      name, as appropriate. The Advisor agrees to assume full liability for any
      contracts or agreements the Advisor, his employees, or his subcontractors,
      if any, enter into on behalf of the Corporation without the express
      knowledge and written consent of the Corporation.

    (c)  The Corporation shall indemnify and hold blameless the Advisor against
      any claims, losses, expenses, costs, obligations, and liabilities arising
      out of, or in connection with, the performance of the Services by the
      Advisor, except for (i) such claims, losses expenses, costs, obligations,
      and liabilities as arise out of the gross negligence or willful injurious
      acts or omissions of the Advisor and (ii) such claims, losses, expenses,
      costs, obligations, and liabilities as the Advisor may be answerable to
      the Corporation for.

9.  Taxes.  The Advisor shall be responsible for the withholding, and payment,
    -----
    as required by law, of all federal, state, and local taxes imposed on the
    Advisor because of the performance of the Services hereunder. Further, the
    Advisor shall comply with all federal, state, and local benefits laws
    applicable to the Advisor, including making deductions and contributions for
    social security and unemployment taxes. Each party to this Agreement shall
    otherwise be responsible for the payment of any other taxes imposed upon it
    or him in connection with, or as a result of, this Agreement.

10. Site of Services.  The Advisor will perform the Services at a location other
    -----------------
    than the premises of the Corporation if possible, or if the Services are
    such that the Services must be performed on the Corporation's premises, the
    Corporation shall provide the Advisor with office space and facilities
    commensurate with that provided to its own employees to the extent necessary
    to perform the Services specified by this Agreement. The Advisor will
    restrict the performance of the Services to a separate assigned work area as
    much as is feasible.

11. Travel Expenses.  The Corporation will reimburse the Advisor for all
    ---------------
    reasonable travel expenses, approved in advance by the Corporation, upon
    receipt of supporting documentation.

12. Inventions.  The Corporation shall compensate the Advisor on a case-by-case
    ----------
    basis for any third party inventions licensed, assigned, or otherwise
    acquired by the Corporation through the efforts of the Advisor or conceived
    and reduced to practice by the Advisor and not otherwise the property of the
    Corporation in whole or in part.

13.  Non-Exclusive Right.  The Corporation may contract with individuals other
     -------------------
    than the Advisor for the Services. The Advisor does not have an exclusive
    right to provide the Services to the Corporation.
<PAGE>

14. Waiver.   Any waiver by the Corporation of a breach of any provision of this
    ------
    Agreement shall not operate or be construed as a waiver of any subsequent
    breach of such provision or any other provision hereof.

15. Severability.  If for any reason any clause or provision of this Agreement,
    -------------
    or the application of any such clause or provision in a particular context
    or to a particular situation, circumstance or person, should be held
    unenforceable, invalid or in violation of law by any court or other
    tribunal, then the application of such clause or provision in contexts or to
    situations, circumstances or persons other than that in or to which it is
    held unenforceable, invalid or in violation of law shall not be affected
    thereby, and the remaining clauses and provisions hereof shall,
    nevertheless, remain in full force and effect.

16. Governing Law.   This Agreement shall be governed by, and construed in
    -------------
    accordance with, the laws of the State of New York.

    IN WITNESS WHEREOF, the Corporation has caused this Agreement to be
    executed, and the Advisor has executed this Agreement, as of the date first
    set forth above.



    KERYX BIOPHARMACEUTICALS, INC.              ADVISOR



  By:_____________________________              By:_____________________

  Name:___________________________

  Title:__________________________