This   COMMON   STOCK   PRIVATE    PLACEMENT
                           AGREEMENT (the  "Agreement") has been entered into as
                           of  February  14,  2000,  by and among  IMMUNOMEDICS,
                           INC., a Delaware corporation (the "Company"), and the
                           PURCHASERS   listed  on  Exhibit  A  (individually  a
                           "Purchaser" and collectively the "Purchasers").

                  This  Agreement has been executed by the parties in connection
with the  private  placement  of shares of Common  Stock (the  "Shares")  of the
Company. The parties hereby agree as follows:

1.       Agreement to Subscribe; Payment; Subscription Irrevocable.
         ---------------------------------------------------------
          (a)  Each Purchaser  hereby  subscribes for the number of Shares shown
               on  Exhibit  A next to its name at a price of  $16.00  per  Share
               payable to the Company;
          (b)  Payment  for the  Shares  shall  take  place no later  than three
               business days after the execution and delivery of this  Agreement
               (the  "Closing").  The Closing  will take place at the offices of
               Sutro & Co., Inc. (the  "Placement  Agent") at 11150 Santa Monica
               Blvd.,  Los Angeles,  CA. At the Closing the Company will deliver
               to the  Purchasers  the Shares  against  payment of the aggregate
               purchase price by wire transfer payable to the Placement Agent on
               behalf  of the  Company  pursuant  to the  instructions  shown on
               Exhibit B. The Shares shall be registered in  Purchasers'  names,
               or the names of designated  nominees,  in such  denominations  as
               shown in Exhibit A.
          (c)  Each  Purchaser  understands  that,  except as  provided  in this
               Agreement,  this  subscription may not be revoked by a Purchaser,
               and that the  execution and delivery of this  Agreement  will not
               constitute  an agreement  between the  Purchaser  and the Company
               until this  Agreement has been accepted by the Company,  and then
               subject to the terms and conditions of this Agreement.

2.       Qualifications of Investor.
         --------------------------
          (a)  Accredited  Investor Status. Each Purchaser hereby represents and
               warrants to the Company that it is an accredited  investor within
               the meaning of Regulation D  promulgated  by the  Securities  and
               Exchange Commission (the "SEC")
          (b)  Each Purchaser represents and warrants that:
               (i)  It has not been formed,  reformed or  recapitalized  for the
                    specific purpose of purchasing the Shares;
               (ii) It has been duly  formed  and is  validly  existing  in good
                    standing  under  the  laws  of  the   jurisdiction   of  its
                    formation,  with full power and  authority to enter into the
                    transactions contemplated by this Agreement; and
               (iii)This  Agreement  has  been  duly  and  validly   authorized,
                    executed,   and  delivered  by  it  and  when  executed  and
                    delivered by the Company, will constitute the valid, binding
                    and enforceable agreement of the Purchaser.

<PAGE>

3.       Independent Investigation.
         -------------------------
          (a)  Independent Investigation. Each Purchaser, in making the decision
               to  purchase   the  Shares   subscribed   for,  has  relied  upon
               independent  investigation  made  by it and  its  representatives
               which  it  deems  to be  adequate  and  they  have  reviewed  the
               Company's  Form 10Q for the quarter ended  September 30, 1999 and
               the pertinent parts of the Company's S-3  Registration  Statement
               filed with the SEC on January 11, 2000.
          (b)  No  Governmental  Recommendation  or  Approval.  The  undersigned
               understands that no federal or state agency has passed on or made
               any recommendation or endorsement of the Shares.

         THE SHARES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 OR
         THE  SECURITIES  LAWS OF ANY STATE AND  THERE ARE  RESTRICTIONS  ON THE
         TRANSFERABILITY OF THE SHARES.

4.       Investment Representations.
         --------------------------
          (a)  Shares Not  Registered;  Indefinite  Holding.  Each Purchaser has
               been advised by the Company,  and understands,  that it must bear
               the  economic  risk  of  an  investment  in  the  Shares  for  an
               indefinite  period of time  because  the Shares have not yet been
               registered under the Securities Act.  Therefore,  the Shares must
               be held by the Purchaser until they are  subsequently  registered
               under the Securities  Act or an exemption from such  registration
               is available for the transfer of the Shares.
          (b)  Purchase  for own Account.  Each  Purchaser  represents  that the
               Shares  are  being  acquired  solely  for  its  own  account  for
               investment  and  not  with  a  view  toward,  or  for  resale  in
               connection with, any  "distribution" (as that term is used in the
               Securities Act and its Rules and Regulations) of any Shares.
          (c)  No Disposition of Shares Without Securities Law Compliance.  Each
               Purchaser  agrees not to subdivide the Shares or to offer,  sell,
               pledge,  hypothecate  or otherwise  transfer or dispose of any of
               the Shares in the absence of an effective  registration statement
               under the Securities Act covering such disposition, or an opinion
               of counsel,  satisfactory to the Company and its counsel,  to the
               effect that registration under the Securities Act is not required
               in respect of such transfer or disposition.
          (d)  Stop-Transfer and Legends on Certificates. Each Purchaser further
               understands  that a  stop-transfer  order  will be  placed on the
               stock-transfer  books of the Company  respecting the certificates
               evidencing the Shares,  and such  certificates  shall bear, until
               such time as the  Shares  shall  have been  registered  under the
               Securities Act or shall have been  transferred in accordance with
               such  an  opinion  of  counsel,  the  following  legend  (or  one
               substantially similar).

         THE SHARES  REPRESENTED BY THIS  CERTIFICATE  HAVE NOT BEEN  REGISTERED
         UNDER THE  SECURITIES  ACT OF 1933, AS AMENDED,  AND MAY NOT BE SOLD OR
         TRANSFERRED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT UNDER
         SAID ACT, OR AN AVAILABLE EXEMPTION THEREUNDER.

               plus any legend that may be required under any  applicable  state
               law.

                                      -2-

<PAGE>

          (e)  "Private Offering"  Exemption;  Reliance on Representations.  The
               undersigned understands that the offer and sale of the Shares are
               not being  registered under the Securities Act in reliance on the
               so-called "private  offering"  exemption provided by Section 4(2)
               of the Securities Act and/or Regulation D promulgated pursuant to
               the  Securities  Act, and that the Company is basing its reliance
               on that  exemption  in part on the  representations,  warranties,
               statements and agreements contained in this Agreement.

5.       Indemnification.
         ----------------
         Each Purchaser agrees to indemnify and hold the Company,  its officers,
         directors  and  stockholders  or any other  person who may be deemed to
         control the Company harmless from any loss, liability, claim, damage or
         expense,   arising  out  of  the   inaccuracy   of  any  of  the  above
         representations,  warranties  or statements or the breach of any of the
         agreements contained in this Agreement,  and this indemnification shall
         survive the purchase and sale of the Shares.

6.       Conditions to the Company's Obligation to Sell.
         ----------------------------------------------
         Each Purchaser  understands  that the Company's  obligation to sell the
Shares is conditioned upon:

          (a)  the receipt  and  acceptance  by the Company of a fully  executed
               Agreement for all of the Shares to be purchased in the particular
               offering (i.e.,  either the initial  offering of a minimum of 1.5
               million Shares or any subsequent  offerings of up to an aggregate
               of an additional 500,000 Shares);  and
          (b)  No injunction, order, investigation,  claim, action or proceeding
               before  any  court  or  governmental  body  shall be  pending  or
               threatened wherein an unfavorable judgment, decree or order would
               restrain, impair or prevent the carrying out of this Agreement or
               any of the transactions  contemplated  thereby,  declare unlawful
               the transactions contemplated by this Agreement or cause any such
               transaction to be rescinded.

7.       Conditions to Purchasers' Obligation to Purchase.
         ------------------------------------------------
         Purchasers'  obligation  to purchase the Stock in  accordance  with the
terms of this Agreement is conditioned  upon:

          (a)  Purchasers shall have received from STARR, GERN, DAVISON & RUBIN,
               counsel for the  Company,  its opinion  dated the Closing Date in
               the form of Exhibit C; and
          (b)  All  of  the   representations  and  warranties  of  the  Company
               contained in this  Agreement  shall be true and correct at and as
               of the Closing Date; and
          (c)  No injunction, order, investigation,  claim, action or proceeding
               before  any  court  or  governmental  body  shall be  pending  or
               threatened wherein an unfavorable judgment, decree or order would
               restrain, impair or prevent the carrying out of this Agreement or
               any  of  the  contemplated  transactions,  declare  unlawful  the
               transactions  contemplated  by this  Agreement  or cause any such
               transaction to be rescinded;
          (d)  The Company shall have delivered to Purchasers the following:
               (i)  a  certificate  of the  Secretary of the Company,  dated the
                    Closing Date, as to the continued and valid existence of the
                    Company,  certifying the attached copy of the By-laws of the
                    Company,  the  authorization of the execution,  delivery and
                    performance of this Agreement,  and the resolutions  adopted
                    by the Board of  Directors  of the Company  authorizing  the
                    actions to be taken by the Company under this Agreement;

                                      -3-

<PAGE>

               (ii) a  certificate  of the  Secretary  of State of the  State of
                    Delaware,  dated a  recent  date,  to the  effect  that  the
                    Company is in good  standing  in the State of  Delaware  and
                    that all annual reports, if any, have been filed as required
                    and, if readily  available that all franchise taxes and fees
                    have been paid in connection therewith;
               (iii)a certified copy of the Certificate of  Incorporation of the
                    Company as filed with the Secretary of State of the State of
                    Delaware, including any amendments thereto; and
          (e)  The Company shall have  received  from these  certain  Purchasers
               pursuant to an  Agreement  dated as of December  15, 1999 between
               those  Purchasers and the Company,  their written  consent to the
               filing of the Shelf Registration  Statement  described in Section
               10 below.

8.       Representations and Warranties of the Company.
         ---------------------------------------------
         The representations and warranties of the Company in this Agreement are
         subject to and qualified by the disclosures  made in the Company's most
         recent Annual Report on Form 10-K and Quarterly Report on Form 10-Q, as
         filed with the SEC (the "SEC Documents"). The Company hereby represents
         and warrants to each Purchaser as of the Closing as follows:

          (a)  Organization.  The  Company  is  a  corporation  duly  organized,
               validly existing and in good standing under the laws of the State
               of  Delaware.  The  Company  is  eligible  to be  treated  as a C
               corporation  under the Internal  Revenue Code of 1986, as amended
               (the "Code").  The Company has all requisite  corporate power and
               authority,  and holds all  licenses,  permits and other  required
               authorizations  from  governmental   authorities,   necessary  to
               conduct  its  business as now being  conducted  or proposed to be
               conducted and to own or lease the properties and assets now owned
               or held under license or lease.  The Company is duly qualified or
               licensed and in good  standing as a foreign  corporation  in each
               jurisdiction  wherein  the  character  of its  properties  or the
               nature of the activities conducted by it makes such qualification
               or  licensing  necessary,  except where the failure to so qualify
               would not have a material adverse effect on the Company.
          (b)  Capitalization.  As of January 11, 2000, the Company's authorized
               capitalization  consists of 70,000,000 shares of Common Stock, of
               which  43,655,709   shares  are  issued  and   outstanding,   and
               10,000,000  shares of preferred  stock,  par value $.01 per share
               (of which 595.5  shares are  designated  as Series F  Convertible
               Preferred  Stock but none of which are issued  and  outstanding).
               15,022,288  shares of Common Stock are reserved for issuance upon
               the  conversion or exercise of convertible  securities,  options,
               warrants or other rights to purchase Common Stock  outstanding as
               of the Closing Date.  All  outstanding  securities of the Company
               are validly issued, fully paid and nonassessable.  No stockholder
               of the Company is entitled to any preemptive  rights with respect

                                      -4-

<PAGE>
               to the purchase or sale of any  securities by the Company.  There
               are no outstanding options, warrants or other rights, commitments
               or  arrangements,  written  or oral,  to  purchase  or  otherwise
               acquire any  authorized  but unissued  shares of capital stock of
               the Company or any security  directly or  indirectly  convertible
               into or  exchangeable  for any  capital  stock of the  Company or
               under which any such option,  warrant or convertible security may
               be issued in the future except otherwise as set forth on Schedule
               8(b).  There are no voting  trusts or  agreements,  stockholders'
               agreements,  pledge agreements,  buy-sell, rights of first offer,
               negotiation  or  refusal  or  proxies  or  similar   arrangements
               relating to any securities of the Company to which the Company is
               a party,  and to the best  knowledge  of the  Company  after  due
               inquiry  there  are no  other  such  trusts,  agreement,  rights,
               proxies or similar arrangements. Except as otherwise set forth on
               Schedule 8(b) or as contemplated  by this Agreement,  none of the
               shares  of  capital  stock of the  Company  is  reserved  for any
               purpose,  and the  Company is neither  subject to any  obligation
               (contingent  or  otherwise),  nor has any option to repurchase or
               otherwise  acquire or retire any shares of its capital stock. (c)
               Due  Authorization,   Valid  Issuance,  Etc.  The  Shares  to  be
               purchased on the Closing Date have been duly authorized and, when
               issued in accordance  with this  Agreement upon the Closing Date,
               will be validly issued, fully paid and non-assessable and will be
               free and clear of all liens  imposed by or through  the  Company,
               subject only to restrictions set forth herein, as applicable,  or
               applicable federal and state securities laws. The issuance,  sale
               and  delivery  of  such  Shares,  will  not  be  subject  to  any
               preemptive  right of  stockholders of the Company or to any right
               of first  refusal or other right in favor of any person or entity
               except for provisions  which have been waived or satisfied and as
               set forth on Schedule 8(c).
          (d)  Subsidiaries.  The  Company  has no  wholly  or  partially  owned
               Subsidiaries  and does not control,  directly or indirectly,  any
               other   corporation,    business   trust,   firm,    partnership,
               association, joint venture, entity or organization. Except as set
               forth on Schedule  8(d),  the Company  does not own any shares of
               stock,  partnership interest, joint venture interest or any other
               security,  equity or interest in any other  corporation  or other
               Person.
          (e)  Company  Power.  The  Company  has the full  corporate  power and
               authority to execute,  deliver and enter into this  Agreement and
               to perform  its  obligations,  and the  execution,  delivery  and
               performance  of  this   Agreement  and  all  other   contemplated
               transactions  have  been duly  authorized  by the  Company.  This
               Agreement  constitutes a legal,  valid and binding  obligation of
               the  Company,   which  is  not  in  contravention  of  any  other
               agreements of the Company,  and this  Agreement is enforceable in
               accordance  with its terms except as such  enforceability  may be
               limited by (a)  bankruptcy,  insolvency,  moratorium  and similar
               laws   affecting   creditors'   rights   generally  and  (b)  the
               availability of remedies under general equitable principles.
          (f)  No Material Adverse Change.  Since September 30, 1999,  except as
               disclosed on Schedule 8(f) there has not at any time been (a) any
               material  adverse  change in the business,  financial  condition,
               operating  results,  business  prospects,  employee  relations or
               customer relations of the Company,  or (b) other adverse changes,
               which  in the  aggregate  have  been  materially  adverse  to the
               Company.  Except  as set  forth  on  Schedule  8(f),  no event or

                                      -5-

<PAGE>

               circumstance  has  occurred or exists with respect to the Company
               or its business, properties,  prospects,  operations or financial
               condition,  which,  under  applicable  law,  rule or  regulation,
               requires  public  disclosure or  announcement  by the Company but
               which has not been so publicly announced or disclosed.
          (g)  Disclosure.  Neither  this  Agreement  nor any of the  schedules,
               exhibits, written statements,  documents or certificates prepared
               or  supplied  by the  Company  with  respect to the  transactions
               contemplated by this  Agreement,  nor any document filed with the
               Securities and Exchange  Commission after January 1, 1999 contain
               any untrue  statement of a material  fact or omit a material fact
               necessary to make the statements contained therein not misleading
               in  light of the  circumstances  under  which  made.  Except  for
               general factors that are common in the market and industry of the
               Company,  there exists no fact or circumstance which, to the best
               knowledge of the Company after due inquiry,  materially adversely
               affects,  or which  could  reasonably  be  anticipated  to have a
               material  adverse  effect on, the existing or expected  financial
               condition,   operating  results,   assets,   customer  relations,
               employee relations or business prospects of the Company.
          (h)  Absence of Certain  Developments.  Except as contemplated by this
               Agreement,  and  except  as set  forth  on  Schedule  8(h)  since
               September  30, 1999 the  Company has not,  nor will have prior to
               the  Closing  Date:  (i) issued  any  securities  (other  than as
               permitted or contemplated by this  Agreement);  (ii) borrowed any
               amount or incurred or became subject to any liabilities (absolute
               or  contingent)   which  involve  $50,000  or  more,  other  than
               liabilities  incurred  in the  ordinary  course of  business  and
               liabilities  under contracts  entered into in the ordinary course
               of business;  (iii)  discharged  or satisfied  any lien,  adverse
               claim  or   encumbrance  or  paid  any  obligation  or  liability
               (absolute or contingent),  other than current liabilities paid in
               the  ordinary  course  of  business;  (iv)  declared  or made any
               payment  or  distribution  of  cash  or  other  property  to  the
               stockholders  of the Company  with respect to the Common Stock or
               purchased or redeemed any shares of Common Stock;  (v) mortgaged,
               pledged or subjected to any lien,  adverse  claim,  charge or any
               other  encumbrance,  any of its properties or assets,  except for
               liens for taxes not yet due and payable;  (vi) sold,  assigned or
               transferred any of its assets, tangible or intangible,  except in
               the  ordinary  course  of  business  and in an  amount  less than
               $50,000,  or disclosed to any person,  firm or entity not subject
               to a confidentiality  obligation with the Company any proprietary
               confidential information; (vii) suffered any extraordinary losses
               or waived any rights of material value; (viii) made any change in
               the nature or operations of the business of the Company;  or (ix)
               resolved or entered  into any  agreement  or  understanding  with
               respect to any of the foregoing.
          (i)  Properties.  The Company has good and marketable  title to all of
               the real property and good title to all of the personal  property
               and  assets  it  purports  to own as set  forth in the  Financial
               Statements,  whether such property is real or personal,  free and
               clear of all liens,  adverse  claims,  charges,  encumbrances  or
               restrictions  of any  nature  whatsoever,  except (a) such as are
               reflected  on  Schedule  8(i),  (b) for  receivables  and charges
               collected in the ordinary  course of business and (c)  immaterial
               exceptions of a routine and customary nature. The Company owns or
               leases all such  properties as are necessary to its operations as
               now conducted  and as presently  proposed to be conducted and all
               such properties are, in all material respects,  in good operating
               condition and repair.

                                      -6-
<PAGE>

          (j)  Taxes.  Except as set forth on  Schedule  8(j),  the  Company has
               timely  filed all federal,  state,  local and foreign tax returns
               and  reports  required  to  be  filed,   and  all  taxes,   fees,
               assessments and governmental  charges of any nature shown by such
               returns and  reports to be due and payable  have been timely paid
               except for those  amounts  being  contested in good faith and for
               which  appropriate  amounts have been reserved in accordance with
               generally  accepted  accounting  principles.   There  is  no  tax
               deficiency  that  has  been,  or,  to the best  knowledge  of the
               Company after due inquiry might be, asserted  against the Company
               that  would  adversely  affect the  business  or  operations,  or
               proposed  business or  operations,  of the Company.  All such tax
               returns and reports were prepared in accordance with the relevant
               rules  and   regulations   of  each   taxing   authority   having
               jurisdiction  over the  Company  and are true  and  correct.  The
               Company has neither  given nor been  requested to give any waiver
               of any statute of limitations relating to the payment of federal,
               state,  local or foreign taxes.  The Company has not been, nor is
               it now being, audited by any federal, state, local or foreign tax
               authorities. The Company has made all required deposits for taxes
               applicable  to the current tax year.  The Company is not, and has
               never been, a member of any  Affiliated  group within the meaning
               of Section 1504 of the Internal  Revenue  Code, as in effect from
               time to time.
          (k)  Litigation.  Except as set forth on Schedule  8(k),  there are no
               actions,  suits,  proceedings,  orders,  investigations or claims
               pending  or,  to the best  knowledge  of the  Company  after  due
               inquiry,  threatened against or affecting the Company,  at law or
               in equity or before or by any federal,  state, municipal or other
               governmental  department,  commission,  board, bureau,  agency or
               instrumentality;  there are no  arbitration  proceedings  pending
               under collective bargaining agreements or otherwise;  and, to the
               best  knowledge  of the Company  after due  inquiry,  there is no
               basis for any of the foregoing.
          (l)  Compliance  with Law.  The Company has  complied in all  material
               respects  with all  applicable  statutes and  regulations  of the
               United States and of all states,  municipalities  and  applicable
               agencies  and foreign  jurisdictions  or bodies in respect of the
               conduct of its business and operations.
          (m)  Trademarks and Patents.  Each trademark,  trade name,  patent and
               copyright (and application  therefor) owned by the Company is not
               subject to any license,  royalty  arrangement,  option or dispute
               and is free and clear of all liens.  To the best knowledge of the
               Company after due inquiry,  none of the trademarks,  trade names,
               patents or copyrights  used by the Company in connection with its
               business infringes any trademark, trade name, patent or copyright
               of others in the United  States or in any other  country,  in any
               way which adversely  affects or which in the future may adversely
               affect the business or operations of the Company. No stockholder,
               officer or director  of the  Company or any other  person owns or
               has any  interest in any  trademark,  trade name,  service  mark,
               patent,  copyright  or  application  therefor,  or trade  secret,
               licenses, invention, information or proprietary right or process,

                                      -7-

<PAGE>
               if any, used by the Company in connection with its business.  The
               Company  has no notice or  knowledge  of any  objection  or claim
               being  asserted  by any person  with  respect  to the  ownership,
               validity  enforceability  or use of any  such  trademarks,  trade
               names,  patents and  copyrights  (and  applications  therefor) or
               challenging or questioning the validity or  effectiveness  of any
               license relating thereto. There are no unresolved conflicts with,
               or pending claims of, any other person,  whether in litigation or
               otherwise,  involving the  trademarks,  trade names,  patents and
               copyrights (and applications  therefor),  and there are no liens,
               encumbrances, adverse claims, or rights of any other person which
               would prevent the Company from fulfilling its  obligations  under
               this  Agreement.  To the best  knowledge of the Company after due
               inquiry,  the business of the Company, as presently conducted and
               as  proposed  to be  conducted  does not and will not  cause  the
               Company to violate any trademark,  trade name, patent, copyright,
               trade secret, license or proprietary interest of any other person
               or  entity,  in any way which  adversely  affects or which in the
               future may  adversely  affect the business or  operations  of the
               Company.
          (n)  Insurance.  Each insurance policy  maintained by the Company with
               respect to its  properties,  assets and business is in full force
               and effect; and the Company is not in default with respect to its
               obligations under any of such insurance policies.  Such insurance
               coverage is in amounts not less than is customarily maintained by
               corporations   engaged  in  the  same  or  similar  business  and
               similarly  situated,  including,  without  limitation,  insurance
               against loss,  damage,  fire,  theft,  public liability and other
               risks.  The  activities  and  operations of the Company have been
               conducted  in a  manner  so  as  to  conform  to  all  applicable
               provisions  of these  insurance  policies and the Company has not
               taken or failed to take any  action  which  would  cause any such
               insurance policy to lapse.
          (o)  Agreements.  Except as set forth on Schedule 8(o), the Company is
               not party to nor bound by any agreement or commitment, written or
               oral, which obligates the Company to make payments to any person,
               or which obligates any person to make payments to the Company, in
               the case of each such agreement in an amount  exceeding  $50,000,
               or which is  otherwise  material to the conduct and  operation of
               the  business or  proposed  business of the Company or any of its
               properties  or  assets,   including,   without  limitation,   all
               shareholder,    employment,    non-competition   and   consulting
               agreements  and  employee  benefit  plans  and  arrangements  and
               collective  bargaining agreements to which the Company is a party
               or by which it is bound. All such agreements are legal, valid and
               binding obligations of the Company, in full force and effect, and
               enforceable in accordance with their respective terms,  except as
               the  enforceability  thereof  may be limited  by (a)  bankruptcy,
               insolvency,  moratorium,  and similar  laws  affecting  creditors
               rights  generally  and (b) the  availability  of  remedies  under
               general  equitable  principles.  The  Company has  performed  all
               obligations  required  to be  performed  by  it,  and  is  not in
               default,  or in receipt of any claim, under any such agreement or
               commitment,  and  the  Company  has  no  present  expectation  or
               intention of not fully  performing all of such  obligations,  nor
               does the Company have any knowledge of any breach or  anticipated
               breach by the other parties to any such  agreement or commitment.
               The Company is not party to any contract,  agreement,  instrument
               or understanding which materially adversely affects the business,
               properties, prospects, operations, assets or condition (financial
               or otherwise) of the Company.

                                       -8-

<PAGE>

          (p)  Undisclosed  Liabilities.  Except as set forth on Schedule  8(p),
               the Company has no  obligation  or  liability  (whether  accrued,
               absolute, contingent,  unliquidated, or otherwise, whether due or
               to become due,  except that, as to contingent  liabilities,  such
               reference is only as to matters which are reasonably  possible of
               assertion  and,  which if asserted,  could  reasonably  result in
               material  liability)  of which the Company knows or has reason to
               know  exists  arising  out of  transactions  entered  into  at or
               included on the September 30, 1999 balance sheet  included in the
               Financial  Statements prior to the Closing Date, or any action or
               inaction at or prior to the Closing  Date,  or any state of facts
               existing at or prior to the Closing Date,  except (i) liabilities
               in an amount less than $50,000 incurred in the ordinary course of
               business  (none of which is a liability  for breach of  contract,
               breach of warranty, torts, infringements, claims or lawsuits); or
               (ii)  liabilities  or  obligations  disclosed in the schedules to
               this Agreement.
          (q)  Employees; Conflicting Agreements. (i) The Company has caused all
               present members of management and all  professional  employees of
               and  consultants  and  advisors  to the  Company,  including  all
               employees and consultants  and advisors  involved in research and
               development, and will cause all such persons in the future, to be
               subject  to  agreements  with  respect  to (a)  nondisclosure  of
               confidential information,  (b) assignment of patents, trademarks,
               copyrights  and  proprietary   rights  to  the  Company  and  (c)
               disclosure  to the Company of  inventions  in form and  substance
               satisfactory to the Purchasers. (ii) To the best knowledge of the
               Company after due inquiry, no stockholder,  director,  officer or
               key  employee  of the  Company  is a  party  to or  bound  by any
               agreement, contract or commitment, or subject to any restrictions
               in connection with any previous or current employment of any such
               person (other than agreements with respect to the Company), which
               adversely  affects,  or which in the future may adversely affect,
               the  business  or the  proposed  business  of the  Company or the
               rights of any of the Purchasers under this Agreement,  including,
               without  limitation,  in respect of Purchasers rights as a holder
               of the Common  Shares and the shares of Common Stock  issuable in
               connection therewith.
          (r)  Compliance  with  Securities  Laws. (i) Assuming the accuracy and
               truth of each of Purchasers  representations set forth in Section
               2, all securities of the Company  heretofore sold and issued were
               sold and issued,  and the Common  Shares were offered and will be
               sold and issued, in compliance with all applicable federal, state
               and foreign securities laws. Neither the Company,  nor any of its
               Affiliates,  nor, to its best  knowledge  after due inquiry,  any
               person or entity  acting on its or their behalf has,  directly or
               indirectly, made any offers or sales of any security or solicited
               any offers to buy any security,  under  circumstances  that would
               require  registration  of the Common Shares under the  Securities
               Act of  1933,  as  amended  (the  "Securities  Act")  or for  the
               offering of the same to be integrated  with any other offering of
               securities;  (ii) The  Company  has not  directly  or  indirectly
               purchased  or redeemed  any shares of Common  Stock during the 30
               days preceding the Closing Date.
          (s)  Environmental Matters.
               (i)  The Company, and all properties owned, operated or leased by
                    the  Company,  have  obtained  and  currently  maintain  all
                    environmental   permits  required  for  their  business  and
                    operations and are in compliance with all such environmental
                    permits.  There are no legal proceedings pending nor, to the
                    best knowledge of the Company after due inquiry,  threatened

                                      -9-

<PAGE>
                    to modify or revoke any such environmental permits.  Neither
                    the Company,  nor any property owned,  operated or leased by
                    the  Company,  has  received any notice from any source that
                    there is lacking any  environmental  permit required for the
                    current use or operation of the business of the Company,  or
                    any property owned, operated or leased by the Company.
               (ii) All real property owned,  operated or leased by the Company,
                    and, to the best knowledge of the Company after due inquiry,
                    all  property  adjacent  to such  properties,  are free from
                    contamination by any hazardous material;  and the Company is
                    not  subject to  environmental  costs and  liabilities  with
                    respect   to   hazardous   materials,   and  no   facts   or
                    circumstances  exist which could give rise to  environmental
                    costs and liabilities with respect to hazardous materials.
               (iii)There is not now, nor has there been in the past, on, in, or
                    under any real property  owned,  leased,  or operated by the
                    Company, or by any of their respective  predecessors (a) any
                    asbestos-containing  materials,  (b) any underground storage
                    tanks, (c) above-ground storage tanks, (d) impoundments, (e)
                    poly-chlorinated biphenyls or (f) radioactive substances
               (iv) The Company, and all properties owned, operated or leased by
                    the Company, comply with all environmental laws
               (v)  Neither  the  Company,  nor any  property  owned,  leased or
                    operated  by the  Company,  has  received or been issued any
                    written request for  information,  or has been notified that
                    it   is  a   potentially   responsible   party   under   the
                    environmental  laws with  respect to any on-site or off-site
                    for which environmental costs and liabilities are asserted.
          t.   No  Brokers.  Except  for the  Placement  Agreement,  no  finder,
               broker,  agent or other  intermediary  has acted on behalf of the
               Company  in  connection  with the  offering  of the  Shares,  the
               execution  of this  Agreement or the  consummation  of any of the
               transactions contemplated by this Agreement.
          u.   Transactions with Affiliates.  Except as previously  disclosed in
               the Company's SEC filings and in the Company's  Proxy  Statement,
               no  director,  officer,  employee,  consultant  or  agent  of the
               Company,  or  member  of the  family  of any such  person  or any
               corporation, partnership, trust or other entity in which any such
               person,  or any  member of the family of any such  person,  has a
               substantial  interest  in or is an  officer,  director,  trustee,
               partner  or  holder of more  than 5% of the  outstanding  capital
               stock thereof,  is a party to any  transaction  with the Company,
               including any contract,  agreement or other arrangement providing
               for the  employment  of,  furnishing  of services by or requiring
               payments to any such person or firm.
          v.   Financial Statements. The financial statements of the Company and
               the related notes contained in the documents that the Company was
               required to file under the  Securities  and Exchange Act of 1934,
               as  amended,  during  the 12  months  preceding  the date of this
               Agreement   ("Exchange  Act  Documents")   present   fairly,   in
               accordance with generally  accepted  accounting  principles,  the
               financial position of the Company as of the dates indicated,  and
               the  results of its  operations  and cash  flows for the  periods
               therein  specified.  Such  financial  statements  (including  the
               related  notes) have been prepared in accordance  with  generally
               accepted  accounting  principles  applied on a  consistent  basis
               throughout  the  periods  therein  specified,  except  as  may be
               disclosed in the SEC Documents.

                                      -10-

<PAGE>


          w.   Accountants.  The  auditing  firm which the Company  expects will
               express their opinion with respect to the financial statements to
               be incorporated by reference from the Company's  Annual Report on
               Form  10-K  for  the  year  ended  December  31,  1999  into  the
               Registration  Statement  (as  defined  below) and the  Prospectus
               which  forms  a  part  thereof,  are  and  shall  be  independent
               accountants  as required by the  Securities Act and the rules and
               regulations promulgated thereunder (the "Rules and Regulations").
          x.   Transfer  Taxes. On the Closing Date, all stock transfer or other
               taxes (other than income  taxes) which are required to be paid in
               connection with the sale and transfer of the Shares to be sold to
               the Purchaser hereunder will be, or will have been, fully paid or
               provided for by the Company and all laws imposing such taxes will
               be or will have been fully complied with.
          y.   Investment Company. The Company is not an "investment company" or
               an   "affiliated   person"  of,  or   "promoter"   or  "principal
               underwriter" for an investment company, within the meaning of the
               Investment Company Act of 1940, as amended.
          z.   Offering Materials.  Other than the SEC Documents and the Private
               Placement   Memorandum  dated  the  date  hereof  (the  "Offering
               Materials"),  the  Company  has  not  distributed  and  will  not
               distribute  prior to the Closing  Date any  offering  material in
               connection with the offering and sale of the Shares.  The Company
               has  not in the  past  nor  will it  hereafter  take  any  action
               independent  of the  Placement  Agent to sell,  offer for sale or
               solicit  offers to buy any  securities of the Company which would
               bring the offer,  issuance or sale of the Shares, as contemplated
               by this  Agreement,  within  the  provisions  of Section 5 of the
               Securities Act, unless such offer,  issuance or sale was or shall
               be within the exemptions of Section 4 of the Securities Act.


9.       Covenants of the Company.
         ------------------------
         The Company covenants and agrees with the Purchasers as follows:

          (a)  Restrictive Legend. (1) The Purchasers acknowledge and agree that
               until such time as the  shares  have been  registered  for resale
               under the 1933 Act as  contemplated  by  Section  10  below,  the
               certificates  for the Shares  will bear a  restrictive  legend as
               described in Section 4(d) of this  Agreement.  (2) Once the Shelf
               Registration  Statement  provided in Section 10 has been declared
               effective, thereafter (i) upon request of a Purchaser the Company
               will  promptly  (but in no event  later than three  Trading  Days
               after receipt of such  Purchaser's  legended  certificates by the
               Company) substitute  certificates  without restrictive legend for
               certificates  for any Shares issued prior to the dates such Shelf
               Registration  Statement  is declared  effective  by the SEC which
               bear  such  restrictive   legend  and  remove  any  stop-transfer
               restriction relating thereto and (ii) the Company shall not place
               any restrictive  legend on certificates  for any Shares issued or
               impose any stop-transfer restriction thereon.

                                      -11-

<PAGE>

          (b)  Form D. The Company  agrees to file a Form D with  respect to the
               Shares  as  required  under  Regulation  D and to  provide a copy
               thereof to Purchaser  promptly after such filing.  Each Purchaser
               agrees to  cooperate  with the  Company in  connection  with such
               filing  and,  upon  request  of  the  Company,   to  provide  all
               information  relating to such Purchaser  reasonably  required for
               such filing.
          (c)  Use of Proceeds.  The proceeds of sale of the Shares will be used
               for continuing  research and development for its existing product
               line  future  clinical  trials and for  general  working  capital
               purposes and in the operation of the Company's business.

10.      Registration of Shares.
         ----------------------
          (a)  Not later than 10  business  days  after the  Closing  Date,  the
               Company  will  file with the SEC a shelf  registration  statement
               (the "Shelf  Registration  Statement") with respect to the resale
               of the Common Shares  beneficially owned by Purchasers  following
               the Closing (the "Registrable Securities").  The Company will use
               its best  efforts  to,  within  120 days  after  the date of such
               filing,  effect the  registrations,  qualifications or compliance
               (including,  without  limitation,  the  execution of any required
               undertaking  to  file  post-effective   amendments,   appropriate
               qualifications   under   applicable   blue  sky  or  other  state
               securities  laws  and  appropriate   compliance  with  applicable
               securities   laws,   requirements   or  regulations)  as  may  be
               reasonably  requested and as would permit or facilitate  the sale
               and   distribution  of  all  Registrable   Securities  until  the
               distribution is complete;  provided that the Company shall not be
               obligated to maintain the effectiveness of the Shelf Registration
               Statement  (and  any  related   qualifications   and  compliance)
               following  such time as the Company  shall  deliver an opinion of
               counsel  reasonably  satisfactory  to the holders of  Registrable
               Securities (such holders are referred to as the "Holders') and in
               form and  substance  satisfactory  to each  Holder  that (i) such
               Holders  may  sell  in  a  single   transaction  all  Registrable
               Securities  then held or issuable to such Holder on a  registered
               securities   exchange  or  NASDAQ   market  under  an  applicable
               exemption from the  registration  requirements  of the Securities
               Act and  all  other  applicable  securities  laws  and  (ii)  all
               transfer  restrictions  and  restrictive  legends with respect to
               such Registrable Securities will be removed upon the consummation
               of such sale.
          (b)  Registration  Procedures.  In connection with the registration of
               any Registrable  Securities  under the Securities Act as provided
               in this  Section 10, the Company  will use its best  efforts,  as
               expeditiously as possible:
               (i)  To  prepare  and file  with the SEC the  Shelf  Registration
                    Statement  with respect to such  Registrable  Securities and
                    use its  best  efforts  to  cause  such  Shelf  Registration
                    Statement to become effective as expeditiously as possible;
               (ii) To  prepare  and  file  with  the SEC  such  amendments  and
                    supplements  to such Shelf  Registration  Statement  and the
                    prospectus used in connection  therewith as may be necessary
                    to keep such Shelf  Registration  Statement  effective until
                    the  disposition  of all  securities in accordance  with the
                    intended methods of disposition by the seller or sellers set
                    forth  in  such  Shelf   Registration   Statement  shall  be
                    completed,   and  to  comply  with  the  provisions  of  the
                    Securities  Act (to the extent  applicable  to the  Company)
                    with respect to such dispositions;

                                      -12-

<PAGE>

               (iii)To furnish  to each  seller of such  Registrable  Securities
                    such number of copies of such Shelf  Registration  Statement
                    and of each  such  amendment  and  supplement  (in each case
                    including  all  exhibits),  such  number  of  copies  of the
                    prospectus  included  in such Shelf  Registration  Statement
                    (including each preliminary prospectus),  in conformity with
                    the  requirements  of the  Securities  Act,  and such  other
                    documents,  as such seller may reasonably  request, in order
                    to facilitate the disposition of the Registrable  Securities
                    owned by such seller;
               (iv) To  use  its  best  efforts  to  register  or  qualify  such
                    Registrable  Securities  covered by such Shelf  Registration
                    Statement  under such other  securities  or blue sky laws of
                    such jurisdictions as any seller reasonably requests, and do
                    any and all other  acts and things  which may be  reasonably
                    necessary or  advisable to enable such seller to  consummate
                    the  disposition in such  jurisdictions  of the  Registrable
                    Securities  owned by such  seller,  except  that the Company
                    will  not  for any  such  purpose  be  required  to  qualify
                    generally  to do  business as a foreign  corporation  in any
                    jurisdiction  wherein it would not, but for the requirements
                    of this Section 10 be obligated to be qualified,  to subject
                    itself to taxation in any such  jurisdiction,  or to consent
                    to general service of process in any such jurisdiction;
               (v)  To  provide  a  transfer  agent and  registrar  for all such
                    Registrable  Securities  covered by such Shelf  Registration
                    Statement  not later than the  effective  date of such Shelf
                    Registration Statement;
               (vi) To notify each seller of such Registrable  Securities at any
                    time when a  prospectus  relating  thereto is required to be
                    delivered  under the Securities Act, of the happening of any
                    event as a result of which the  prospectus  included in such
                    Shelf Registration Statement contains an untrue statement of
                    a  material  fact or omits  any fact  necessary  to make the
                    statements  therein not  misleading,  and, at the request of
                    any such seller,  the Company  will prepare a supplement  or
                    amendment  to  such   prospectus   so  that,  as  thereafter
                    delivered to the purchasers of such Registrable  Securities,
                    such  prospectus  will not contain an untrue  statement of a
                    material  fact or omit to state any fact  necessary  to make
                    the statements therein not misleading.  The Purchasers agree
                    to suspend,  upon request of the Company, any disposition of
                    Registrable   Securities   pursuant   to  the   Registration
                    Statement  contemplated  hereby  during any  period,  not to
                    exceed one 30-day period per  circumstance  or  development.
                    (vii) To use its best efforts to cause all such  Registrable
                    Securities  to be  listed  on each  securities  exchange  or
                    automated  over-the-counter  trading system on which similar
                    securities issued by the Company are then listed;
               (viii) To enter into such customary agreements (including, in the
                    event   Purchasers   elect  to  engage  an   underwriter  in
                    connection  with  the  Shelf  Registration   Statement,   an
                    underwriting   agreement   containing  customary  terms  and

                                      -13-

<PAGE>
                    conditions)  and take all such other  actions as  reasonably
                    required in order to expedite or facilitate the  disposition
                    of such Registrable Securities; and
               (ix) To  make   available   for   inspection  by  any  seller  of
                    Registrable  Securities,  all financial  and other  records,
                    pertinent   corporation  documents  and  properties  of  the
                    Company,  and cause the  Company's  officers,  directors and
                    employees to supply all information  reasonably requested by
                    any such seller in  connection  with the Shelf  Registration
                    Statement.
               (x)  With  a view  to  making  available  to  the  Purchaser  the
                    benefits of Rule 144 (or its  successor  rule) and any other
                    rule or  regulation  of the SEC that may at any time  permit
                    the   Investor  to  sell   Shares  to  the  public   without
                    registration,  the Company covenants and agrees to: (i) make
                    and keep public  information  available,  as those terms are
                    understood  and defined in Rule 144;  (ii) file with the SEC
                    in a timely manner all reports and other documents  required
                    of the  Company  under  the  Securities  Act and  under  the
                    Exchange  Act;  and  (iii)  furnish  to the  Purchaser  upon
                    request,  as long as the  Purchaser  owns  at  least  25,000
                    Shares,  (A) a written  statement by the Company that it has
                    complied with the reporting  requirements  of the Securities
                    Act and the Exchange Act, (B) a copy of the  Company's  most
                    recent  Annual  Report on Form 10-K or  Quarterly  Report on
                    Form  10-Q,  and  (C)  such  other  information  as  may  be
                    reasonably  requested in order to avail the Purchaser of any
                    rule or  regulation  of the SEC that  permits the selling of
                    any such Shares without registration.
          (c)  Registration and Selling  Expenses.  All expenses incurred by the
               Company  in  connection  with  the  Company's  performance  of or
               compliance with this Section 10,  including,  without  limitation
               (i) all  registration  and filing fees  (including  all  expenses
               incident to filing with the National  Association  of  Securities
               Dealers,  Inc.),  (ii)  blue  sky fees and  expenses,  (iii)  all
               necessary  printing and duplicating  expenses,  and (iv) all fees
               and  disbursements  of counsel  and  accountants  retained by the
               Company  (including  the  expenses  of  any  audit  of  financial
               statements)   (all  such  expenses  being  called   "Registration
               Expenses"), will be paid by the Company.
          (d)  The  Company  will,  in  any  event,   in  connection   with  any
               registration  statement,  pay its internal  expenses  (including,
               without limitation, all salaries and expenses of its officers and
               employees  performing  legal,   accounting  or  other  duties  in
               connection therewith and expenses of audits of year-end financial
               statements),  the expense of liability insurance and the expenses
               and fees for listing the  securities  to be  registered on one or
               more securities exchanges or automated  over-the-counter  trading
               systems on which  similar  securities  issued by the  Company are
               then listed.
          (e)  Nothing in this  Agreement  shall be  construed  to  prevent  any
               Holder or Holders of Registrable  Securities  from retaining such
               counsel as they shall choose at their own expense.

11.      Indemnification.
         ---------------
          (a)  The Company shall indemnify, to the extent permitted by law, each
               Holder of  Registrable  Securities,  its  officers,  trustees and
               directors,  if any,  and each person,  if any, who controls  such
               Holder  within the  meaning of the  Securities  Act,  against all
               losses,  claims,  damages,  liabilities  and expenses  (under the
               Securities  Act or common law or otherwise)  caused by any untrue
               statement  or  alleged  untrue   statement  of  a  material  fact

                                      -14-

<PAGE>

               contained in any  registration  statement or  prospectus  (and as
               amended  or   supplemented  if  the  Company  has  furnished  any
               amendments or supplements) or any preliminary  prospectus,  which
               registration  statement,  prospectus  or  preliminary  prospectus
               shall  be   prepared   in   connection   with  the   contemplated
               registration,  or caused by any  omission or alleged  omission to
               state therein a material  fact  required to be stated  therein or
               necessary to make the statements  therein not misleading,  except
               insofar as such losses, claims, damages,  liabilities or expenses
               are caused by any untrue  statement or alleged  untrue  statement
               contained  in  or  by  any  omission  or  alleged  omission  from
               information furnished in writing by such holder to the Company in
               connection  with  the  contemplated   registration  provided  the
               Company  will not be liable  pursuant to this  Section 10 if such
               losses, claims, damages, liabilities or expenses have been caused
               by any selling security holder's failure to deliver a copy of the
               registration  statement  or  prospectus,  or  any  amendments  or
               supplements.
          (b)  In connection with any  registration  statement in which a Holder
               is  participating,  each such Holder shall furnish to the Company
               in writing such  information  as is  reasonably  requested by the
               Company for use in any such registration  statement or prospectus
               and shall severally,  but not jointly,  indemnify,  to the extent
               permitted  by law, the Company,  its  directors  and officers and
               each person,  if any, who controls the Company within the meaning
               of the  Securities  Act,  against  any losses,  claims,  damages,
               liabilities and expenses  resulting from any untrue  statement or
               alleged  untrue  statement of a material  fact or any omission or
               alleged  omission of a material fact required to be stated in the
               registration   statement  or   prospectus  or  any  amendment  or
               supplement  or  necessary  to make  the  statements  therein  not
               misleading,  but only to the extent such losses, claims, damages,
               liabilities  or  expenses  are caused by an untrue  statement  or
               alleged  untrue  statement  contained  in or by  an  omission  or
               alleged omission from information so furnished in writing by such
               Holder in connection with the contemplated  registration.  If the
               offering  pursuant  to any  such  registration  is  made  through
               underwriters,   each  such   Holder   agrees  to  enter  into  an
               underwriting  agreement in customary form with such  underwriters
               and to indemnify such underwriters, their officers and directors,
               if any, and each person who controls such underwriters within the
               meaning of the Securities Act to the same extent as provided with
               respect  to  indemnification  by  such  Holder  of  the  Company.
               Notwithstanding  the  foregoing  or any other  provision  of this
               Agreement,  in no event  shall a Holder be liable for any losses,
               claims,  damages,  liabilities  or  expenses in excess of the net
               proceeds received by such Holder in the offering.
          (c)  Promptly after receipt by an  indemnified  party of notice of the
               commencement of any action or proceeding,  such indemnified party
               will,  if a claim is made  against the  indemnifying  party under
               such  Section,  notify the  indemnifying  party in writing of the
               commencement;  but the  omission  so to notify  the  indemnifying
               party will not relieve it from any liability which it may have to
               any indemnified party otherwise than under such Section.  In case
               any such action or proceeding is brought  against any indemnified
               party,   and  it   notifies   the   indemnifying   party  of  the
               commencement,   the  indemnifying   party  will  be  entitled  to
               participate,  and, to the extent that it wishes, jointly with any
               other  indemnifying  party  similarly  notified,  to  assume  the
               defense,  with counsel  approved by such  indemnified  party, and
               after  notice  from the  indemnifying  party to such  indemnified
               party of its election so to assume the defense,  the indemnifying
               party  will not be liable to such  indemnified  party  under such
               Section for any legal or any other expenses subsequently incurred

                                      -15-

<PAGE>

               by such  indemnified  party in connection with the defense (other
               than reasonable  costs of  investigation)  unless incurred at the
               written request of the indemnifying  party.  Notwithstanding  the
               above,  the  indemnified  party  will  have the  right to  employ
               counsel of its own choice in any such action or proceeding if the
               indemnified  party has  reasonably  concluded  that  there may be
               defenses  available to it which are different  from or additional
               to those of the indemnifying party, or counsel to the indemnified
               party is of the opinion  that it would not be  desirable  for the
               same counsel to  represent  both the  indemnifying  party and the
               indemnified party because such  representation  might result in a
               conflict of interest  (in either of which cases the  indemnifying
               party will not have the right to assume  the  defense of any such
               action  or  proceeding  on  behalf  of the  indemnified  party or
               parties  and such legal and other  expenses  will be borne by the
               indemnifying  party). An indemnifying party will not be liable to
               any  indemnified  party for any  settlement of any such action or
               proceeding  effected  without  the  consent of such  indemnifying
               party.
          (d)  If  the  indemnification  provided  for  in  this  Section  11 is
               unavailable  under  applicable  law to an  indemnified  party  in
               respect of any losses, claims, damages or liabilities referred to
               therein,  then each  applicable  indemnifying  party,  in lieu of
               indemnifying  such  indemnified  party,  shall  contribute to the
               amount paid or payable by such  indemnified  party as a result of
               such losses, claims, damages or liabilities in such proportion as
               is  appropriate  to reflect the relative  fault of the Company on
               the one hand and of the Holders on the other in  connection  with
               the  statements  or  omissions  which  resulted  in such  losses,
               claims,  damages,  or liabilities,  as well as any other relevant
               equitable  considerations.  The relative  fault of the Company on
               the one hand and of the Holders on the other shall be  determined
               by  reference  to,  among  other  things,  whether  the untrue or
               alleged  untrue  statement of a material  fact or the omission to
               state a material  fact  relates to  information  supplied  by the
               Company  or by the  Holders  and the  parties'  relative  intent,
               knowledge,  access to information  and  opportunity to correct or
               prevent such statement or omission. The amount paid or payable by
               a  party  as  a  result  of  the  losses,   claims,  damages  and
               liabilities referred to above shall be deemed to include, subject
               to the  limitations  set forth in this  Section  11, any legal or
               other  fees or  expenses  reasonably  incurred  by such  party in
               connection with  investigating  or defending any action or claim.
               Notwithstanding  the  foregoing  or any other  provision  of this
               Agreement,  in no event shall a Holder be required to  contribute
               any amount in excess of the net proceeds  received by such Holder
               in the offering  less any amount paid by such Holder  pursuant to
               any other  provision  of this  Section  11.  No person  guilty of
               fraudulent misrepresentation (within the meaning of Section 11(f)
               of the Securities Act) will be entitled to contribution  from any
               person who is not guilty of such fraudulent misrepresentation.
          (e)  Promptly  after receipt by the Company or any Holder of notice of
               the commencement of any action or proceeding, such party will, if
               a claim for contribution is to be made against another party (the
               "contributing  party"),  notify  the  contributing  party  of the

                                      -16-

<PAGE>
               commencement;  but the  omission  so to notify  the  contributing
               party will not relieve it from any liability which it may have to
               any other party other than for contribution under this Agreement.
               In case any such action,  suit, or proceeding is brought  against
               any party,  and such party notifies a  contributing  party of the
               commencement,   the  contributing   party  will  be  entitled  to
               participate  with the notifying party and any other  contributing
               party similarly notified.

12.      Company Indemnities.
         -------------------
         The Company agrees to indemnify,  defend and hold  Purchasers and their
         officers, trustees,  directors,  partners,  employees,  consultants and
         agents (the  "Purchasers'  Indemnitees")  harmless from and against any
         damages  or  third-party   claims   incurred  or  suffered  by  any  of
         Purchasers'  Indemnitees  as a  result  of  or  arising  out  of  or in
         connection with the Company's breach of any  representation,  warranty,
         covenant or agreement of the Company  contained in this  Agreement  and
         such  indemnity  shall  survive  the  execution  and  delivery  of this
         Agreement.  The applicable Purchasers' Indemnities will promptly notify
         the Company of any potential  indemnification  claim upon  discovery of
         the facts  supporting the potential claim and, if such  indemnification
         is based on a third-party  claim,  allow the Company to defend,  manage
         and resolve the matter at the Company's cost and with the  indemnities'
         reasonable cooperation.

13.      Amendments and Waivers.
         ----------------------
         This  Agreement  and it's  exhibits and  schedules set forth the entire
         agreement and understanding  among the parties as to the subject matter
         and  merges  and  supersedes  all  prior  discussions,  agreements  and
         understandings  of any and every nature among them.  This Agreement may
         be amended  only by mutual  written  agreement  of the  Company and the
         Purchasers,  and the Company may omit to take any action required to be
         performed by it, and any breach of any covenant, agreement, warranty or
         representation  may be waived,  only if the  Company has  obtained  the
         written  consent or waiver of a majority in interest of the Purchasers.
         No course of dealing  between or among any persons  having any interest
         in  this  Agreement  will be  deemed  effective  to  modify,  amend  or
         discharge any part of this  Agreement or any rights or  obligations  of
         any person under or by reason of this Agreement.

14.      Successors and Assigns.
         ----------------------
         This  Agreement  shall be binding  upon and inure to the benefit of the
         Company and it's  permitted  successors  and assigns and Purchasers and
         their successors and assigns.  The provisions which are for Purchasers'
         benefit as  purchasers or holders of the Common Shares are also for the
         benefit of, and  enforceable  by, any subsequent  holder of such Common
         Shares.

15.      Notices.
         -------
         All notices,  demands and other communications to be given or delivered
         under or by  reason of the  provisions  of this  Agreement  shall be in
         writing  and  shall be deemed to have  been  given  personally  or when
         mailed by certified or registered  mail,  return receipt  requested and
         postage  prepaid,  and  addressed to the  addresses  of the  respective
         parties set forth below or to such  changed  addresses  as such parties

                                      -17-

<PAGE>

         may have fixed by notice; provided,  however, that any notice of change
         of address shall be effective only upon receipt:

                           If to the Company:
                           Immunomedics, Inc.
                           300 American Road
                           Morris Plains, New Jersey 07950
                           Attn: Dr. David M. Goldenberg

         With a Copy to:

         Starr, Gern,  Davison & Rubin, 103 Eisenhower  Parkway,  Roseland,  NJ
         07068

         If to the Purchasers:
         At the addresses shown on Exhibit A with a copy to Sutro & Co., Inc.

16.      Governing Law; Consent to Jurisdiction.
         --------------------------------------
         The validity,  performance,  construction  and effect of this Agreement
         shall be governed by those laws of the State of New Jersey. The parties
         irrevocably  consent to the  jurisdiction of the courts of the State of
         New Jersey and of any federal court located in such State in connection
         with any  action  or  proceeding  arising  out of or  relating  to this
         Agreement,  any  document  or  instrument  delivered  pursuant  to,  in
         connection with or simultaneously  with this Agreement,  or a breach of
         this Agreement or any such document or instrument.

17.      Counterparts.
         ------------
         This  Agreement  may be  executed  in any number of  counterparts  and,
         notwithstanding  that  any of the  parties  did not  execute  the  same
         counterpart,  each of such  counterparts  shall,  for all purposes,  be
         deemed an original,  and all such counterparts shall constitute one and
         the same instrument binding on all of the parties.

18.      Headings.
         --------
         The headings of the  Sections  are inserted as a matter of  convenience
         and for  reference  only and in no way define,  limit or  describe  the
         scope of this Agreement or the meaning of any provision.

19.      Severability.
         ------------
         In the event that any provision of this Agreement or the application of
         any  provision  is  declared  to  be  illegal,   invalid  or  otherwise
         unenforceable  by a court of competent  jurisdiction,  the remainder of
         this Agreement shall not be affected except to the extent  necessary to
         delete such  illegal,  invalid or  unenforceable  provision  unless the
         provision  held invalid shall  substantially  impair the benefit of the
         remaining portion of this Agreement.

20.      Governing Law.
         -------------
         This Agreement  shall be governed by and interpreted in accordance with
         the laws of the State of New Jersey.

                                      -18-

<PAGE>

21.      Exculpation Among Purchasers.
         ----------------------------
         Each Purchaser  acknowledges and agrees that it is not relying upon any
         other  Purchaser,  or  any  officer,  director,   employee  partner  or
         affiliate  of any such other  Purchaser,  in making its  investment  or
         decision to invest in the  Company or in  monitoring  such  investment.
         Each  Purchaser  agrees that no Purchaser nor any  controlling  person,
         officer,  director,  stockholder,  partner,  agent or  employee  of any
         Purchaser shall be liable for any action  heretofore or hereafter taken
         or omitted to be taken by any of them relating to or in connection with
         the Company or the Shares, or both.

22.      Actions by Purchasers.
         ---------------------
         Any actions  permitted to be taken by holders or  Purchasers  of Shares
         and any  consents  required  to be  obtained  from the same  under this
         Agreement,  may be taken or given only by, in the case of  consents  or
         actions requiring approval of a Purchaser, by the applicable Purchaser,
         and in all other  cases,  except to the  extent  inconsistent  with any
         explicit provision of this Agreement,  only by holders of a majority in
         interest of the Common Stock.

23.      Publicity.
         ---------
         The Company will not issue any public  statement,  press release or any
         other public  disclosure  listing Purchaser as one of the purchasers of
         the Shares without Purchaser's prior written consent.

                            [Signature Page Follows]

                                      -19-

<PAGE>



                          IN WITNESS  WHEREOF,  this Agreement was duly executed
on the 14th day of February, 2000.

                                              IMMUNOMEDICS, INC.

                                               By: /s/ David M. Goldenberg
                                                   -----------------------------
                                                   David M. Goldenberg, M.D.,
                                                   Chairman

                                      -20-

<PAGE>

                                   Purchasers

  The following is a list of the purchasers whose signatures are on the file.

DCF Capital L.P.                                       75,000
DCF Life Sciences Fund LTD                             25,000
Dresdner RCM Global Investor                          200,000
Franklin Templeton Group                              300,000
Global Lifesciences Fund                              749,375
Aspen Global Life Sciences Fund                           625
JMG Capital                                            75,000
Moore Global Investments, Ltd.                        160,000
Remington Investment Strategies, L.P.                  40,000
Palantir Capital                                      100,000
Beacon Funds                                           75,000
1st New York Securities                                75,000
Westcliff Master Fund L.P.                             40,530
Westcliff Partners L.P.                                33,470
Westcliff Partners SA L.P.                              8,300
Westcliff Long/Short L.P.                               9,940
Westcliff Small Cap Fund L.P.                           7,760
Samuel Lupin, M.D.                                     17,000
F/B/O Arnold M. Lupin IRA                              25,000
Lupin Foundation                                       15,000
Sontag Partners                                        10,000
Robert D. Marcus, M.D.                                 10,000
E. Ralph Lupin, M.D.                                    3,000
Fagey Lupin Fischman                                   10,000
Taylor - Schabelman Group                               5,000
Taylor - Schabelman Group                               5,000
Morton Coleman, M.D.                                  104,000
Robert M. Gelfand, M.D.                                20,000
Mark Pasmentier, M.D.                                   6,000
Mark Goldblatt                                         20,000
Aires Domestic Fund, L.P.                              30,482
Aires Domestic Fund II, L.P.                            5,139
The Aires Master Fund                                  64,379