Exhibit (d)(4)

                             STOCKHOLDERS' AGREEMENT

         STOCKHOLDERS' AGREEMENT (the "Agreement"), dated as of October 30,
2000, by and among Cangene Corporation, a Canadian corporation ("Parent"), AC
Acquisition Subsidiary, Inc., a Maryland corporation and a wholly owned direct
subsidiary of Parent ("Acquisition"), and, severally and not jointly, each of
the Stockholders listed on Schedule I hereto (each, a "Stockholder," and
collectively, the "Stockholders") of Chesapeake Biological Laboratories, Inc., a
Maryland corporation (the "Company"). Capitalized terms used and not defined
herein have the meanings given them in the Merger Agreement, dated as of the
date hereof, by and among Parent, Acquisition and the Company (as amended from
time to time, the "Merger Agreement").

         WHEREAS, concurrently herewith, Parent, Acquisition and the Company are
entering into the Merger Agreement, a copy of which in the form to be executed
has been delivered to each Stockholder, pursuant to which, among other things,
Acquisition will make a cash tender offer (the "Offer") for all of the issued
and outstanding shares of common stock, par value $.01, of the Company (each, a
"Share," and one or more, the "Shares"), and Acquisition will subsequently be
merged with and into the Company (the "Merger"), in each case upon the terms and
subject to the conditions set forth in the Merger Agreement;

         WHEREAS, each Stockholder Beneficially Owns (as defined in Section
2(a)) the number of Shares, shares of Series A-1 convertible preferred stock
(the "Convertible Preferred Stock") and warrants to purchase Shares (the
"Warrants"), all set forth opposite such Stockholder's name in column 3 of
Schedule I hereto; and

         WHEREAS, in order to induce Parent and Acquisition to enter into the
Merger Agreement and to perform their obligations thereunder and as a condition
thereof, the Stockholders are entering into this Agreement.

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

SECTION 1.  TENDER OF SHARES.

         (a) Each Stockholder hereby agrees to tender the Shares, shares of
Convertible Preferred Stock and Warrants (collectively, the "Company
Securities") Beneficially Owned by such Stockholder, or cause such Company
Securities to be tendered, into the Offer promptly after Parent causes
Acquisition to commence the Offer, but in no event later than five (5) Business
Days after the date on which Stockholder receives the Offer Documents for
tendering such Company Securities. Each Stockholder further agrees that such
Stockholder shall not withdraw any Company Securities so tendered unless and
until the Termination Date occurs. With respect to the Shares tendered pursuant
to this Section 1, each Stockholder will receive the same price per Share (but
in any event not less than $4.60 per Share) received by the other stockholders
of the Company pursuant to the Offer. In the case of any shares of Convertible
Preferred Stock



owned by a Stockholder, Acquisition shall pay the tender offer price per Share
multiplied by the number of shares of common stock into which such shares of
Convertible Preferred Stock are convertible. In the case of any Warrants owned
by a Stockholder, Acquisition shall purchase such Warrants for a purchase price
equal to the difference between the exercise price thereof and the tender offer
price per share, multiplied by the number of shares of common stock for which
such Warrants are then exercisable. For purposes of this Agreement, the
"Termination Date" shall be the first to occur of the close of business on (a)
the date that Acquisition terminates the Offer in accordance with the terms of
the Merger Agreement, (b) the date the Offer expires in accordance with the
terms of the Merger Agreement, or (c) the date the Merger Agreement is
terminated pursuant to Article 8 of the Merger Agreement, in each case without
such Shares being purchased by Acquisition pursuant to the Offer.

         (b) Acquisition agrees that (i) no shares of Convertible Preferred
Stock may be converted by Acquisition prior to the Tender Offer Purchase Time
(as defined in the Merger Agreement) without the prior written direction of the
Stockholder owning such shares, and (ii) no Warrants shall be exercised by
Acquisition until after they have been purchased by Acquisition pursuant to the
Offer without the prior written direction of the Stockholder owning such
Warrants.

SECTION 2.  AGREEMENT TO VOTE; IRREVOCABLE PROXY.

         (a) Each Stockholder hereby agrees that during the period commencing on
the date of this Agreement and continuing until the first to occur of the
Effective Time (as defined in the Merger Agreement) or the Termination Date, at
any meeting of the holders of the Shares, however called, or in connection with
any written consent of the holders of Shares, such Stockholder shall vote (or
cause to be voted) the Company Securities entitled to vote and held of record or
Beneficially Owned by such Stockholder, whether owned on the date hereof or
hereafter acquired, (i) in favor of approval of the Merger Agreement, all
transactions contemplated thereby, and any actions required in furtherance
thereof and hereof (including election of such directors of the Company as
Parent is entitled to designate pursuant to Section 1.3(a) of the Merger
Agreement); (ii) against any action or agreement that is intended, or could
reasonably be expected, to impede, interfere with, or prevent the Offer or the
Merger or result in a breach in any respect of any covenant, representation or
warranty or any other obligation or agreement of the Company or any of its
subsidiaries under the Merger Agreement or this Agreement; and (iii) except as
specifically requested in writing in advance by Parent, against any of the
following actions (other than the Merger and the transactions contemplated by
the Merger Agreement and this Agreement) that are submitted to a vote of the
holders of the Shares: (A) any extraordinary corporate transaction, such as a
merger, consolidation or other business combination involving the Company or any
of its subsidiaries or affiliates; (B) any sale, lease, transfer or disposition
by the Company or any of its subsidiaries of any assets outside the ordinary
course of business or any assets which in the aggregate are material to the
Company and its subsidiaries taken as a whole, or a reorganization,
recapitalization, dissolution or liquidation of the Company or any of its
subsidiaries or affiliates; (C)(1), except as contemplated by the Merger
Agreement with respect to the Series B Preferred Stock, any change in the
present capitalization of the Company or any amendment of the Company's Articles
of Incorporation or Bylaws; (2) any other material change in the corporate
structure or business of the Company or any of its subsidiaries; or (3)

                                      -2-


any other action or agreement that is intended, or could reasonably be expected,
to impede, interfere with or prevent the Offer, the Merger or the transactions
contemplated by this Agreement or the Merger Agreement. None of the Stockholders
shall enter into any agreement or understanding with any Person, the effect of
which would be inconsistent with or violative of the provisions and agreements
contained in Section 1 or 2 hereof.

         As used in this Agreement, the term "Beneficially Own" or "Beneficial
Ownership" with respect to any securities means having "beneficial ownership" of
such securities as determined pursuant to Rule 13d-3 under the Exchange Act,
including pursuant to any agreement, arrangement or understanding, whether or
not in writing, except that the term shall not include Shares which a
Stockholder has the right to acquire under any of the Company Stock Options
unless such Shares have been acquired upon exercise of such Company Stock
Options. Holders of the Convertible Preferred Stock are deemed to Beneficially
Own the Shares into which such shares of Convertible Preferred Stock are
convertible, and holders of Warrants are deemed to Beneficially Own the Shares
for which the Warrants are exercisable. Without duplicative counting of the same
securities by the same holder, securities Beneficially Owned by a Stockholder
shall include securities Beneficially Owned by all other Persons with whom a
Stockholder would constitute a "group" within the meaning of Section 13(d)(3) of
the Exchange Act.

         (b) Effective on the date that all waiting periods under the HSR Act
applicable to the acquisition of the Shares pursuant to the Offer or to Section
3 of this Agreement have been terminated or shall have expired and any other
notices to or approvals, authorizations or consents of any other Governmental
Entity required in respect thereto shall have been filed or obtained and until
the Termination Date, and in order to secure its obligations hereunder, each
Stockholder hereby grants to, and appoints John Langstaff and Alex Glasenberg,
in their respective capacities as officers of Parent, and any individual who
shall hereafter succeed to any such office of Parent, and any other designee of
Parent, and each of them individually, with full power of substitution and
resubstitution, such Stockholder's true and lawful irrevocable proxy to vote
such Stockholder's Company Securities entitled to vote, or grant a consent or
approval in respect of such Stockholder's Company Securities, on such matters
and as indicated in Section 2(a) above. Each Stockholder (i) agrees to take such
further action and execute such other instruments as may be necessary to effect
the intent of this proxy, (ii) hereby represents that any proxy heretofore given
in respect of the Stockholder's Company Securities is not irrevocable, and (iii)
hereby revokes any proxy previously granted by such Stockholder with respect to
its Company Securities. Each Stockholder understands and acknowledges that
Parent and Acquisition are entering into the Merger Agreement in reliance on
such Stockholder's execution and delivery of this irrevocable proxy. Each
Stockholder hereby affirms that this irrevocable proxy is given in connection
with the execution of this Agreement and the Merger Agreement, and further
affirms that this irrevocable proxy is coupled with an interest in this
Agreement for the term stated herein and may under no circumstances be revoked
by the Stockholder prior to the Termination Date. Each Stockholder hereby
ratifies and confirms all that the proxy or proxies may lawfully do or cause to
be done by virtue hereof. This proxy is executed and intended to be irrevocable
in accordance with the provisions of Section 2-507 of the MGCL. This proxy shall
terminate automatically on the Termination Date.

                                      -3-


SECTION 3.  GRANT OF OPTION.

         (a) Subject to the terms of this Section 3, each Stockholder hereby
grants to Acquisition (or its designee), effective on the date hereof, an
irrevocable option (each, an "Option") to purchase all Company Securities
Beneficially Owned by such Stockholder at a purchase price per Share equal to
the Per Share Amount or, in the case of shares of Convertible Preferred Stock
and Warrants, at the purchase price described in Section 1(a) of this Agreement.

         (b) Acquisition may exercise the Options, in whole but not in part, at
any time following the occurrence of a Purchase Event (as defined below);
provided that the Options shall expire and be of no further force and effect
upon the earliest to occur (the "Expiration Date") of (i) the Tender Offer
Purchase Time or (ii) at the close of business on the third business day after
the receipt by Parent of a Superior Proposal Notice pursuant to Section
8.1(d)(i) of the Merger Agreement or (iii) the sixtieth (60th) day after the
exercise of the Options, if the Option Closing shall not have occurred.
Notwithstanding anything herein to the contrary, Acquisition, at its option, may
elect, pursuant to this Section 3(b) and Sections 8.1 and 8.3 of the Merger
Agreement, either to exercise the Options or to accept payment of the Breakup
Fee provided for in Section 8.3 of the Merger Agreement, but shall not be
entitled under any circumstance to exercise the Options and retain the Breakup
Fee. In the event Acquisition determines to exercise the Options, Acquisition
shall notify the Company of its waiver of receipt of the Breakup Fee pursuant to
the Merger Agreement.

         (c) As used herein, a "Purchase Event" shall mean the receipt by Parent
of a Superior Proposal Notice pursuant to Section 8.1(d)(i) of the Merger
Agreement.

         (d) To exercise the Options, Acquisition shall, prior to the Expiration
Date, give written notice to the Stockholder who granted such Option specifying
the time for the closing (the "Option Closing") of such purchase. The Option
Closing shall be held at the office of Hartman & Craven LLP, 460 Park Avenue,
New York, New York 10022 on the date that is no later than three business days
after the date on which each of the conditions set forth in Section 3(e) below
has been satisfied or waived by Acquisition.

         (e) The occurrence of the Option Closing shall be subject to the
satisfaction of each of the following conditions:

                  (i) to the extent necessary, all waiting periods under the HSR
Act applicable to the purchase of the Shares pursuant to Section 3 of this
Agreement have been terminated or shall have expired and any other notices to or
approvals, authorizations or consents of any other Governmental Entity required
in respect thereto shall have been filed or obtained; and

                  (ii) no preliminary or permanent injunction or other order,
decree or ruling issued by any court of governmental or regulatory authority,
domestic or foreign, of competent jurisdiction prohibiting the exercise of an
Option or the delivery of Shares shall be in effect.

                                      -4-


         (f) At the Option Closing, (i) Acquisition (or its designee) shall pay,
by wire transfer, an amount equal to the product of (A) the Per Share Amount and
(B) the number of Shares (on an as converted basis in the case of the
Convertible Preferred Stock and as described in Section 1(a) of this Agreement
in the case of Warrants) owned by such Stockholder; and (ii) each Stockholder
whose Company Securities are being purchased shall deliver or shall cause to be
delivered to Acquisition a certificate or certificates, or other documentation,
evidencing such Stockholder's Company Securities, and such Stockholder agrees
that such Company Securities shall be transferred free and clear of all liens.
All such certificates or other documents representing Company Securities shall
be duly endorsed in blank, or with appropriate stock powers, duly executed in
blank, attached thereto, in proper form for transfer, with the signature of such
Stockholder thereon guaranteed, and with all applicable taxes paid or provided
for.

SECTION 4.  AFTER-ACQUIRED SHARES.

         Notwithstanding anything herein to the contrary, any Company Securities
acquired by such Stockholder after the date hereof, whether by exercise of
Company Stock Options, by purchase, by conversion or exchange or by inheritance
or bequest or otherwise, shall be subject to all of the representations,
warranties, covenants and agreements of such Stockholder contained herein. In
the event of a share dividend or distribution, or any change in the Company
Securities by reason of any share dividend, split-up, recapitalization,
combination, exchange of shares or the like, the term "Company Securities" shall
be deemed to refer to and include the Company Securities as well as all such
share dividends and distributions and any shares into which or for which any or
all of the Company Securities may be changed, exchanged, converted into or
exercised for.

SECTION 5.  OTHER COVENANTS, REPRESENTATIONS AND WARRANTIES.

         Each Stockholder hereby represents, warrants and covenants on behalf of
such Stockholder only to Parent and Acquisition as of the date hereof and as of
the Tender Offer Purchase Time as follows:

                                      -5-


         (a) On the date hereof, such Stockholder is the Beneficial Owner of the
number of Company Securities set forth opposite such Stockholder's name in
column 3 of Schedule I hereto. On the date hereof, the Company Securities set
forth opposite such Stockholder's name in column 3 of Schedule I hereto
constitute all of the Company Securities owned of record or Beneficially Owned
by such Stockholder. Except as set forth on Schedule I hereto, such Stockholder
owns such Company Securities free and clear of all liens, claims, charges,
security interests, mortgages or other encumbrances, and such Company Securities
are not subject to any rights of first refusal, put rights, other rights to
purchase or encumber, or to any restrictions other than this Agreement as to the
encumbrance, disposition or voting of such Company Securities. Such Stockholder
has controlling voting power and sole power to issue instructions with respect
to the matters set forth in Section 2 hereof, sole power of disposition, sole
power of conversion, sole power to demand dissenters' rights and sole power to
agree to all of the matters set forth in this Agreement, in each case with
respect to all of the Company Securities set forth opposite such Stockholder's
name in column 3 of Schedule I hereto, without limitations, qualifications or
restrictions on such rights, except those arising under marital property laws or
general fiduciary principles applicable to such Stockholder.

         (b) Such Stockholder has the legal capacity, power and authority to
enter into and perform all of such Stockholder's obligations under this
Agreement. The execution, delivery and performance of this Agreement by such
Stockholder will not violate any other agreement to which such Stockholder is a
party including, without limitation, any voting agreement, stockholder agreement
or voting trust. This Agreement has been duly and validly executed and delivered
by such Stockholder and, assuming the due authorization, execution and delivery
by Parent and Acquisition, constitutes a valid, legal and binding agreement of
such Stockholder, enforceable against such Stockholder in accordance with its
terms, except as such enforceability may be limited by any applicable
bankruptcy, insolvency, reorganization, moratorium or other similar laws
affecting the enforcement of creditors' rights generally or by marital property
laws applicable to such Stockholder, and except as the availability of equitable
remedies may be limited by the application of general principles of equity
(regardless of whether such equitable principles are applied in a proceeding at
law or in equity). There is no beneficiary or holder of a voting trust
certificate or other interest of any trust of which such Stockholder is trustee
who is not a party to this Agreement and whose consent is required for the
execution and delivery of this Agreement or the consummation by any Stockholder
of the transactions contemplated hereby.

         (c) (i) No filing with or notice to, and no permit, authorization,
consent or approval of, any Governmental Entity is necessary on the part of such
Stockholder for the execution of this Agreement by such Stockholder or the
consummation by such Stockholder of the transactions contemplated hereby; and
(ii) none of the execution, delivery or performance of this Agreement by such
Stockholder, the consummation by such Stockholder of the transactions
contemplated hereby nor compliance by such Stockholder with any of the
provisions hereof will (A) result in a violation or breach of, or constitute
(with or without notice or lapse of time or both) a default (or give rise to any
right of termination, amendment, cancellation or acceleration or Lien) under any
of the terms, conditions or provisions of any note, bond, mortgage, indenture,
lease, license, contract, agreement, understanding or other instrument or
obligation to which such Stockholder

                                      -6-


is a party or by which such Stockholder or any of such Stockholder's properties
or assets may be bound; or (B) conflict with or violate any order, writ,
injunction, decree, law, statute, rule or regulation applicable to the
Stockholder or any of such Stockholder's properties or assets.

         (d) No broker, finder or investment banker is entitled to any
brokerage, finder's or other fee or commission in connection with the
transactions contemplated by the Merger Agreement based upon arrangements made
by or on behalf of such Stockholder (other than in his capacity as an officer or
director of the Company).

         (e) Such Stockholder shall not, in its capacity as a Stockholder,
directly or indirectly, encourage, solicit, participate in or initiate
discussions or negotiations with or provide any non-public information to any
Person or group (other than Parent and Acquisition or any designees of Parent
and Acquisition) concerning any Third Party Acquisition. In addition, such
Stockholder, solely in its capacity as a Stockholder, will not, and will
instruct his agents and affiliates not to, directly or indirectly, make or
authorize any public statement, recommendation or solicitation in support of any
Acquisition Proposal made by any Person or group (other than Parent or
Acquisition).

         (f) Such Stockholder shall not, directly or indirectly: (i) tender its
Company Securities in any tender offer or exchange offer for the Shares other
than the Offer; (ii) except as contemplated by this Agreement or the Merger
Agreement, otherwise offer for sale, sell, transfer, tender, pledge, encumber,
assign or otherwise dispose of, or enter into any contract, option or other
arrangement or understanding with respect to or consent to the offer for sale,
transfer, tender, pledge, encumbrance, assignment or other disposition of, any
or all of its Company Securities; (iii) except as contemplated by this
Agreement, grant any proxies or powers of attorney, deposit any of its Company
Securities into a voting trust or enter into a voting agreement with respect to
any Company Securities; or (iv) take any action that would make any
representation or warranty of such Stockholder contained herein untrue or
incorrect or have the effect of preventing or impairing such Stockholder from
performing its obligations under this Agreement.

         (g) Such Stockholder hereby acknowledges that such Stockholder has
received a true and correct copy of the Merger Agreement, that such Stockholder
has read and understands the provisions thereof.

         (h) Such Stockholder understands and acknowledges that Parent and
Acquisition are relying upon the foregoing representations, warranties and
covenants by such Stockholder and on such Stockholder's execution and delivery
of this Agreement in entering into the Merger Agreement.

SECTION 6.  CONDITIONS TO OBLIGATIONS OF PARENT AND ACQUISITION.

         Each Stockholder acknowledges and agrees that the obligations of Parent
and Acquisition to consummate the Offer and the Merger are subject to the
satisfaction of each of the conditions set forth in the Merger Agreement.

                                      -7-


SECTION 7.  FURTHER ASSURANCES.

         From time to time, at Parent's request and without further
consideration, each Stockholder agrees to execute and deliver such additional
documents and take all such further lawful action as may be necessary or
desirable to consummate and make effective, and to cause the Company to
consummate and make effective, in the most expeditious manner practicable, the
transactions contemplated by this Agreement.

SECTION 8.  STOP TRANSFER; FORM OF LEGEND.

         Each Stockholder agrees and covenants to Parent that such Stockholder
shall not (a) transfer or encumber or agree to transfer or encumber any of such
Stockholder's Company Securities prior to the Effective Time, except pursuant to
this Agreement, or (b) request that the Company register the transfer
(book-entry or otherwise) of any certificate or uncertificated interest
representing any of such Stockholder's Company Securities, in either case
without the consent of the Parent. If reasonably requested by Parent, any
certificates or other documents representing the Stockholders' Company
Securities shall contain the following legend:

                  "The securities represented by this certificate are subject to
                  certain restrictions on transfer and other terms of a
                  Stockholders' Agreement, dated as of October__, 2000, among
                  Cangene Corporation, AC Acquisition Subsidiary, Inc., and the
                  parties listed on the signature pages thereto, a copy of which
                  is on file in the principal office of Cangene Corporation."

SECTION 9. INDEMNIFICATION.

         (a) After the Tender Offer Purchase Time, subject to the limitations
set forth in this Section 9, the Parent and its affiliates (collectively, the
"Parent Indemnitees") shall each be indemnified and reimbursed and held harmless
to the extent set forth in this Section 9 by each of the Stockholders severally
and not jointly in respect of any and all damages, losses, costs, expenses,
liabilities, judgments, awards, fines, sanctions, penalties, claims, charges and
amounts paid in settlement, including, without limitation, the reasonable costs,
fees and expenses of attorneys, accountants and other agents and
representatives, in each case net of any proceeds of insurance policies received
by such Parent Indemnitee in connection therewith ("Damages") incurred by any
Parent Indemnitee as a direct result of any material misrepresentation in any
representation or warranty of such Stockholder contained in Sections 5(a)
through 5(d) of this Agreement.

         (b) If any Parent Indemnitee shall believe that such Parent Indemnitee
is entitled to indemnification pursuant to this Section 9 in respect of any
Damages, such Parent Indemnitee shall give to each indemnifying Stockholder
prompt written notice thereof in such form and manner specified in Section
13(h). The failure of such Parent Indemnitee to give notice of any claim for
indemnification promptly shall not adversely affect such Parent Indemnitee's
right to indemnity hereunder except to the extent the indemnifying Stockholder
or Stockholders are

                                      -8-


prejudiced by such failure. All such claims for indemnification must be made not
later than midnight on the date that is one year after the Tender Offer Purchase
Time.

         (c) Parent Indemnitees shall, in good faith, defend against any claim,
suit or proceeding that could result in a claim for Damages under this Section 9
and shall use reasonable efforts to minimize the extent of such Damages. No
Parent Indemnitee shall settle any claim, suit or proceeding without the consent
of each indemnifying Stockholder, which consent shall not be unreasonably be
held; provided that the Parent Indemnitee need not obtain the consent of any
Stockholder who denies any indemnification obligation with respect to such
claim, suit or proceeding.

SECTION 10. TERMINATION; SURVIVAL.

         The representations, warranties, covenants and agreements contained
herein shall terminate on and shall not survive the Termination Date.
Notwithstanding the foregoing, if the Tender Offer Purchase Time shall have
occurred, the representations and warranties of the Stockholders contained in
Sections 5(a) through 5(d) and the provisions of Sections 9 and 12 of this
Agreement shall be deemed to survive for a period of one year after the Tender
Offer Purchase Time.

SECTION 11. STOCKHOLDER CAPACITY.

         No Person executing this Agreement who is or becomes during the term
hereof a director or officer of the Company makes any agreement or understanding
herein in his or her capacity as such director or officer. Each Stockholder
signs solely in its capacity as the Beneficial Owner of its Company Securities.

SECTION 12. DISPUTE RESOLUTION.

         (a) Any dispute or difference between any one or more Stockholders, on
the one hand, and Parent or Acquisition, on the other hand, arising under
Section 9, but excluding any suit for specific performance as provided in
Section 13(l), which the parties are unable to resolve themselves shall be
submitted to and resolved by arbitration as provided herein. Any disputing party
may request the American Arbitration Association (the "AAA") to designate one
arbitrator, who shall be qualified as an arbitrator under the standards of the
AAA, who shall be a retired or former judge of any appellate or trial court of
the State of Maryland, any United States appellate court or any United States
District Court for the District of Maryland, who is, in any such case, not
affiliated with any party in interest to such arbitration, and who has
substantial professional experience with regard to legal matters.

         (b) The arbitrator shall consider the dispute at issue in Baltimore,
Maryland at a mutually agreed upon time within 60 calendar days (or such longer
period as may be acceptable to the parties to the arbitration or as directed by
the arbitrator) after the designation of the arbitrator. The arbitration
proceeding shall be held in accordance with the rules for commercial arbitration
of the AAA in effect on the date of the initial request by the disputing party
that gave rise to the

                                      -9-


dispute to be arbitrated (as such rules are modified by the terms of this
Agreement or may be further modified by mutual agreement of the disputing
parties) and shall include an opportunity for the parties to conduct discovery
in advance of the proceeding. Notwithstanding the foregoing, the disputing
parties shall agree that they will attempt, and they intend that they and the
arbitrator should use its best efforts in that attempt, to conclude the
arbitration proceeding and have a final decision from the arbitrator within 120
calendar days after the designation of the arbitrator; provided, however, that
the arbitrator shall be entitled to extend such 120 calendar day period for a
total of two 120 calendar day periods. The arbitrator shall deliver a written
award with respect to the dispute to each of the parties to the arbitration, who
shall promptly act in accordance therewith. Each party to such arbitration
agrees that any award of the arbitrator shall be final, conclusive and binding
and that it will not contest any action by any other party thereto in accordance
with the award of the arbitrator. It is specifically understood and agreed that
any party may enforce any award rendered pursuant to the arbitration provisions
of this Section 12 by bringing suit in any court of competent jurisdiction.

SECTION 13. MISCELLANEOUS.

         (a) This Agreement and the Merger Agreement constitute the entire
agreement between the parties with respect to the subject matter hereof and
supersede all other prior agreements and understandings, both written and oral,
between the parties with respect to the subject matter hereof. This Agreement
may not be assigned by any Stockholder except in connection with a transfer of
its Company Securities. Parent or Acquisition may assign, in its sole
discretion, its rights and obligations hereunder to any direct or indirect
wholly owned subsidiary of Parent.

         (b) All rights, powers and remedies provided under this Agreement or
otherwise available in respect hereof at law or in equity shall be cumulative
and not alternative, and the exercise of any thereof by any party shall not
preclude the simultaneous or later exercise of any other such right, power or
remedy by such party.

         (c) The failure of any party hereto to exercise any right, power or
remedy provided under this Agreement or otherwise available in respect hereof at
law or in equity, or to insist upon compliance by any other party hereto with
its obligations hereunder, and any custom or practice of the parties at variance
with the terms hereof, shall not constitute a waiver by such party of its right
to exercise any such or other right, power or remedy or to demand such
compliance.

         (d) This Agreement may not be amended, changed, supplemented, waived or
otherwise modified or terminated, with respect to any Stockholder, except upon
the execution and delivery of a written agreement executed by Parent,
Acquisition and such Stockholder; provided that Schedule I hereto may be
supplemented by Parent by adding the name and other relevant information
concerning any Stockholder of the Company who agrees to be bound by the terms of
this Agreement (by executing a counterpart signature page hereof) without the
agreement of any other party hereto, and thereafter such added Stockholder shall
be treated as a "Stockholder" for all purposes of this Agreement.

                                      -10-


         (g) If any provision of this Agreement or the application thereof to
any Person or circumstance is held invalid or unenforceable, the remainder of
this Agreement and the application of such provision to other Persons or
circumstances shall not be affected thereby and to such end the provisions of
this Agreement are agreed to be severable.

         (h) All notices, requests, claims, demands and other communications
hereunder shall be in writing and shall be given (and shall be deemed to have
been received upon actual receipt or at the time described in evidence of
delivery by the applicable carrier) by delivery in Person or deposit with a
recognized overnight courier service (notices may be given by facsimile but will
only be deemed delivered upon actual receipt) to the respective parties as
follows:

         if to any Stockholder:

         At the address set forth opposite such Stockholder's name in column 2
of Schedule I hereto.


         With a copy to:

                  Piper Marbury Rudnick & Wolfe LLP
                  6225 Smith Avenue
                  Baltimore, Maryland  21209
                  Attn:  Richard C. Tilghman, Jr., Esq.
                  Facsimile:  (410)580-3274

         if to Parent or Acquisition:

                  Cangene Corporation
                  3403 American Drive
                  Units 3/4
                  Mississauga, Ontario
                  L4V 1T4 Canada
                  Attn:    Alex Glasenberg
                  Chief Financial Officer

         with a copy to:

                  Hartman & Craven LLP
                  460 Park Avenue
                  New York, New York 10022
                  Attn:    Edward I. Tishelman, Esq.
                  Joel I. Frank, Esq.

or to such other address as the Person to whom notice is given may have
previously furnished to the others in writing in the manner set forth above.

                                      -11-


         (i) This Agreement shall be governed and construed in accordance with
the laws of the State of Maryland without regard to the principles of conflicts
of laws thereof.

         (j) The descriptive headings used herein are inserted for convenience
of reference only and are not intended to be part of or to affect the meaning or
interpretation of this Agreement.

         (k) Each Stockholder agrees that this Agreement and the obligations
hereunder shall attach to such Stockholder's Company Securities and shall be
binding upon any Person to which record or Beneficial Ownership of such Company
Securities shall pass, whether by operation of law or otherwise, including,
without limitation, such Stockholder's heirs, guardians, administrators or
successors. Notwithstanding any transfer of Company Securities, the transferor
shall remain liable for the performance of all obligations of the transferor
under this Agreement. This Agreement shall be binding upon and inure solely to
the benefit of each party hereto and its successors and permitted assigns and
nothing in this Agreement express or implied is intended to or shall confer upon
any other Person any rights, benefits or remedies of any nature whatsoever under
or by reason of this Agreement.

         (l) Each of the Stockholders hereby acknowledges and agrees that its
failure to perform its agreements and covenants hereunder will cause irreparable
injury to Parent and Acquisition for which damages, even if available, will not
be an adequate remedy. Accordingly, each Stockholder hereby consents to the
issuance of injunctive relief by any court of competent jurisdiction to compel
performance of such Stockholder's obligations and to the granting by any court
of the remedy of specific performance of its obligations hereunder.

         (m) This Agreement may be executed in one or more counterparts, each of
which shall be deemed to be an original but all of which shall constitute one
and the same agreement.

         IN WITNESS WHEREOF, Parent and Acquisition have caused this
Stockholders' Agreement to be duly executed, and each Stockholder has duly
executed this Agreement, as of the day and year first above written.

                                       CANGENE CORPORATION

                                       By: /s/ Alex Glasenberg
                                           ---------------------------------
                                           Name:  Alex Glasenberg
                                           Title: Chief Financial Officer

                                       AC ACQUISITION SUBSIDIARY, INC.

                                       By: /s/ Alex Glasenberg
                                           ---------------------------------
                                           Name: Alex Glasenberg
                                           Title: Chief Financial Officer

                                      -12-


                                       STOCKHOLDERS

                                       /s/ Harvey L. Miller
                                       --------------------
                                       Name: Harvey L. Miller

                                       Corporate Opportunities Fund, L.P.
                                       By: SMM Corporate Management, LLC
                                       By: /s/ Robert Weinstein
                                           ---------------------------------
                                           Name: Robert Weinstein
                                           Title: Manager

                                       Corporate Opportunities Fund
                                          (Institutional), L.P.
                                       By: SMM Corporate Management, LLC
                                       By: /s/ Robert Weinstein
                                           ---------------------------------
                                           Name: Robert Weinstein
                                           Title: Manager

                                       /s/ John T. Botek
                                       -----------------
                                       Name: John T. Botek

                                       /s/ John T. Janssen
                                       -------------------
                                       Name: John T. Janssen

                                       /s/ Thomas P. Rice
                                       ------------------
                                       Name: Thomas P. Rice

                                       /s/ Joanne W. Tew
                                       -----------------
                                       Name: Joanne W. Tew

                                       /s/ Charles M. Proby
                                       --------------------
                                       Name: Charles M. Proby

                                       /s/ Narlin B. Beaty
                                       -------------------
                                       Name: Narlin B. Beaty

                                       LAB Partners

                                       By: /s/ Lillian Hahn
                                           ---------------------------------
                                           Name: Lillian Hahn
                                           Title: Managing Partner

                                       /s/ Regis F. Burke
                                       ------------------
                                       Name: Regis F. Burke

                                      -13-



                                   SCHEDULE I



                                                                             NUMBER OF           RESTRICTIONS
         STOCKHOLDER                         ADDRESS                       SHARES OWNED             IF ANY
                                                                                       
        Harvey Miller            13737 Cuba Road Cockseyville, MD            82,500
                                              21030

Corporate Opportunities Fund,     c/o James C. Gale, Investment         2,106 shares of
             L.P.                  Manager, 126 East 56th St.,       Convertible Preferred
                                           24th Floor               Stock (convertible into
                                    New York, New York 10022           140,400 shares of
                                                                          Common Stock)
                                                                      Warrants to purchase
                                                                     7,020 shares of Common
                                                                      Stock (at $1.50 per
                                                                             share)

 Corporate Opportunities Fund     c/o James C. Gale, Investment         11,406 shares of
    (Institutional), L.P.          Manager, 126 East 56th St.,       Convertible Preferred
                                           24th Floor               Stock (convertible into
                                   New York, New York 10022            764,400 shares of
                                                                         Common Stock)
                                                                      Warrants to purchase
                                                                    38,020 shares of Common
                                                                      Stock (at $1.50 per
                                                                             share)

        John T. Botek             3808 Yellowstone Court Ellicot             75,000
                                          City, MD 21042

       John T. Janssen            4508 Stonecrest Drive Ellicot              66,300
                                          City, MD 21043

        Thomas P. Rice            4209 Buckskin Wood Dr. Ellicot            152,500
                                          City MD 21042

                                      -14-


        Joanne W. Tew              911 Arran Road Baltimore,                232,150
                                            MD 21239

       Charles M. Proby         11807 Meylston Drive Lutherville,             7,000
                                            MD 21093

       Narlin B. Beaty           13406 Blythenia Road Phoenix,              128,905
                                            MD 21131

         LAB Partners                      LAB Partners                      66,603
                                    c/o Lillian Hahn, Manging
                                             Partner
                                  17201 NE 13th Avenue N. Miami
                                         Beach, FL 33162

        Regis F. Burke             6 Kincaid Court Baldwin,                  51,200
                                            MD 21013