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                                EXHIBIT 10.25

                           Unit Purchase Agreement


            THIS AGREEMENT is made as of March 12, 1997, by and between Alpha 1
Biomedicals, Inc., a Delaware corporation (the "Company"), and each of the
investors listed in Schedule 1 attached hereto (hereinafter collectively
referred to as the "Investors" and individually as an "Investor"). Capitalized
terms used herein are defined in Section 8 hereof.

            The parties hereto hereby agree as follows:

            Section 1.  Purchase and Sale of Units.

            1.01  Purchase and Sale. At the Closing, the Company shall sell to
the Investor and each Investor shall purchase from the Company the number of
Units, each Unit consisting of (i) 500,000 shares (the "Unit Shares") of common
stock, par value $.001 per share, of the Company ("Common Stock") and (ii)
warrants to purchase 165,000 shares of Common Stock (the "Class D Warrants"),
set forth opposite the name of such Investor on Schedule 1 attached hereto at a
purchase price of $50,000 per Unit. The number of Units purchased by all
Investors in the aggregate shall not exceed seven Units.

            1.03  The Closing.  The closing of the purchase and sale of the
Units (the "Closing") shall take place at the offices of Covington & Burling,
1201 Pennsylvania Avenue, N.W., Washington, D.C.  20004, at 10:00 a.m. on
such date as the parties hereto shall mutually determine.

            Section 2.  Deliveries at Closing.  At the Closing, the following
deliveries shall be made and agreements entered into:

            2.01  Common Stock and Class D Warrants.  The Company shall
deliver to each Investor:

            (a)   a copy of the resolutions of the Company's Board of
Directors authorizing the sale and issuance of the Units, certified by the
Secretary of the Company;

            (b)   a stock certificate registered in the name of the Investor
evidencing the number of Unit Shares purchased by the Investor; and

            (c)   a Class D Warrant certificate registered in the name of the
Investor evidencing the number of Class D Warrants purchased by the Investor.

            2.02  Cash Payment. Each Investor shall pay to the Company, by wire
transfer of immediately available funds to an account designated by the Company
or by certified or official bank check, the amount set forth opposite the name
of such Investor on Schedule 1 attached.

            2.03  Registration Rights Agreement. The Company and the Investors
shall enter into a Registration Rights Agreement with respect to the
registration for resale of (i) the Unit Shares and (ii) the shares of Common

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Stock issuable upon the exercise of the Class D Warrants in form attached hereto
as Exhibit A (the "Registration Rights Agreement") .

            2.04  Warrant Agreement. The Company and the Investors shall enter
into a Warrant Agreement setting forth the terms of the Class D Warrants in the
form attached hereto as Exhibit B, (the "Warrant Agreement").

            Section 3.  Representations and Warranties of the Company.

            The Company hereby represents and warrants to each of the Investors
as follows:

            3.01. Organization.  The Company is a corporation duly organized,
validly existing and in good standing under the laws of the State of
Delaware.  The Company has all requisite corporate power and authority to
carry on its business as it currently is conducted and to own or lease and
operate its assets, properties and business.

            3.02  Capitalization.

            (a)   As of the date of this Agreement, the authorized capital stock
of the Company consists of (i) 20,000,000 shares of Common Stock, 9,477,429
shares of which are issued and outstanding, and (ii) 1,000,000 shares of
Preferred Stock, of which no shares are issued or outstanding.

            (b)   All of the issued and outstanding shares of Common Stock are
duly authorized, validly issued, fully paid and nonassessable.

            (c)   Except as set forth on Schedule 2, there are no outstanding
subscriptions, options, warrants, rights (including conversion or preemptive
rights), commitments, agreements, understandings or arrangements to which the
Company is a party, whether oral or written, pursuant to which the Company is
obligated to issue any shares of its capital stock.

            3.03  Subsidiaries.  The Company has no subsidiaries.

            3.04  Financial Statements. The Company has delivered to the
Investors audited balance sheets of the Company at December 31, 1994 and 1995,
and the related statements of operations, stockholders' equity and cash flows
for each year then ended, including the notes thereto (the "Company Financial
Statements"), accompanied by the opinion thereon of Price Waterhouse L.L.P. The
Company has also delivered to the Investors the unaudited balance sheet of the
Company at September 30, 1996, and the related unaudited statements of
operations, stockholders' equity and cash flow for the nine months then ended,
including the notes thereto (the "Company Interim Financial Statements"). The
Company Financial Statements present fairly in all material respects the
financial position of the Company as of December 31, 1994 and 1995, and the
results of operations and changes in financial position of the Company for the
respective one-year periods then ended, and the Company Interim Financial
Statements present fairly in all material respects the financial position of the
Company as of September 30, 1996, and the results of operations and changes in
financial position for the nine-month period then ended, in each case in
conformity with generally accepted accounting principles applied on a basis
consistent with that of prior periods, except that the Company Interim


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Financial Statements may be subject to normal year-end adjustments that are not
in the aggregate material.

            3.05  SEC Reports. Since January 1, 1994, all reports and proxy
statements required to be filed by the Company with the Securities and Exchange
Commission (the "SEC") pursuant to the Securities Exchange Act of 1934 (the
"1934 Act") complied in all material respects with the applicable requirements
of the 1934 Act and the applicable rules and regulations thereunder, and did not
include at the time of filing any untrue statement of a material fact or omit to
state a material fact concerning the Company necessary in order to make the
statements contained therein, in light of the circumstances under which they
were made, not misleading.

            3.06  No Violation of Law. Except as will not have a Material
Adverse Effect, the Company's operations have been conducted in accordance with
all applicable laws, regulations and other requirements of all governmental
bodies having jurisdiction over the Company and the Company has all licenses,
permits, orders or approvals from governmental bodies required for the conduct
of its business. Except as will not have a Material Adverse Effect, none of the
real or personal property owned, leased, occupied or operated by the Company, or
the ownership, leasing, occupancy or operation thereof, is in violation of any
applicable law, code, rule, regulation, ordinance, license or permit (including,
but not limited to, those related to building, zoning, environmental matters or
employee health and safety). No notice from any governmental body or other
Person has been served upon the Company or upon any property owned, leased,
occupied or operated by the Company claiming any violation of any such law,
code, rule, regulation, ordinance, license or permit, or requiring, or calling
attention to the need for, any work, repairs, construction, alterations or
installation on or in connection with such property, except such notices with
which the Company has complied or except as will not have a Material Adverse
Effect.

            3.07  Undisclosed Liabilities. Except as will not have a Material
Adverse Effect, the Company does not have any debts, liabilities or obligations
of any nature, secured or unsecured, whether accrued, absolute, contingent or
otherwise, whether due or to become due, including, but not limited to,
liabilities or obligations on account of taxes, other governmental charges,
duties, penalties, interest, pension plan obligations or indebtedness for
borrowed money, except:

            (a)   to the extent set forth or reserved against the Company
Financial Statements or the Company Interim Financial Statements; and

            (b)   normal and usual current liabilities incurred, and normal and
usual obligations under agreements entered into, in the ordinary course of
business after September 30, 1996.

            3.08  Absence of Certain Changes or Events. Except as disclosed in
the SEC Filings, since December 31, 1995, the business of the Company has been
operated only in the usual and ordinary course of business and there has not
been:

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            (a)   any damage, destruction or loss (whether or not covered by
insurance) of properties, assets or the business of the Company that has had a
Material Adverse Effect;

            (b)   any change in the accounting methods or practices followed by
the Company or any change in the accrual of liabilities or in depreciation,
amortization or inventory valuation policies, rates or methods theretofore used
or adopted;

            (c)   any sale, lease, abandonment or other disposition by the
Company of any interest in real property or, other than in the ordinary course
of business and other than those that will not have a Material Adverse Effect,
of any machinery, equipment or other operating property;

            (d)   any sale, assignment, transfer, license or other disposition
by the Company of any patent, trademark, servicemark, trade name, brand name,
copyright (or pending application for any patent, trademark, servicemark, trade
name or copyright), invention, process, know-how, formula, trade secret or
interest thereunder or other intangible asset, the transfer of which has had or
will have a Material Adverse Effect; or

            (e)   any declaration, setting aside or payment of any dividend or
other distribution on or in respect of shares of capital stock, or any direct or
indirect redemption, retirement, purchase or other acquisition by the Company of
any such shares of capital stock.

            3.09  Tax Matters.

            (a)   The Company has duly, properly, accurately and timely filed
all tax returns required to be filed by it, and has paid, or will pay on a
timely basis, all taxes shown to be due and payable on such returns, all
deficiencies and assessments notices that have been received by it, and all
other taxes due and payable by it, except for taxes, deficiencies and
assessments that are being contested in good faith and for which appropriate
reserves have been established or the nonpayment of which would not have a
Material Adverse Effect.

            (b)   There are no liens for unpaid federal, state and local
taxes on any of the assets of the Company.

            3.10  Absence of Defaults. Except as will not have a Material
Adverse Effect, (i) the Company is not, nor is it alleged to be, in default
under, or in breach of any term or provision of, any contract, agreement, lease,
license, commitment, instrument, or fiduciary or other obligation and (ii) to
the knowledge of the Company, all material contracts, agreements, commitments
and obligations to which the Company is a party are valid and binding agreements
of the parties thereto and are in full force and effect. To the knowledge of the
Company, no other party to any contract, agreement, lease, license, commitment,
instrument, or fiduciary or other obligation to which the Company is party is in
default thereunder, or in breach of any term or provision thereof, except as
will not have a Material Adverse Effect.

            3.11  Litigation. Except as set forth in the SEC Filings, there is
no material (i) suit, action or claim, (ii) investigation or inquiry by any


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administrative agency or governmental body, or (iii) legal, administrative or
arbitration proceeding pending or, to the knowledge of the Company, threatened
against the Company or any of the properties, assets or business of the Company.
There is no material outstanding order, writ, injunction or decree against or
relating to the Company or any of the capital stock, properties, assets or
business of the Company.

            3.12  Validity and Authorization. The Company has full corporate
power to enter into this Agreement, the Registration Rights Agreement and the
Warrant Agreement and to perform its obligations hereunder and thereunder. The
execution and delivery of this Agreement, the Registration Rights Agreement and
the Warrant Agreement, and the consummation of the transactions contemplated
hereby and thereby, have been duly and validly authorized by all necessary
corporate action. This Agreement constitutes and, upon the execution and
delivery thereof by the parties thereto, each of the Registration Rights
Agreement and the Warrant Agreement will constitute a legal, valid and binding
agreement of the Company that is enforceable against the Company in accordance
with its terms, except to the extent that enforceability may be limited by
applicable bankruptcy, insolvency, reorganization, moratorium and similar laws
affecting creditors' rights generally.

            3.13  No Conflicts. The execution and delivery by the Company of
this Agreement, the Registration Rights Agreement and the Warrant Agreement, and
compliance with the respective terms hereof and thereof, by the Company do not
and will not (i) conflict with or result in a breach of the terms, conditions or
provisions of, (ii) constitute a default under, (iii) result in the creation of
any lien, security interest, charge or encumbrance upon the Company's capital
stock or properties pursuant to, (iv) give any third party the right to
accelerate any obligation under, (v) result in a violation of, or (vi) except
for the registrations, qualifications and notices contemplated by the
Registration Rights Agreement, require any authorization, consent, approval,
exemption or other action by or notice to any court or administrative or
governmental body pursuant to the Certificate of Incorporation or Bylaws of the
Company, any law, statute, rule or regulation to which the Company is subject,
or any agreement, instrument, order, judgment or decree to which the Company is
subject or by which it is bound.

            3.14  Authorization of Shares. The Unit Shares have been duly
authorized and, upon issuance in accordance with the terms of this Agreement,
will be validly issued, fully paid and nonassessable. 660,000 shares of Common
Stock issuable upon the exercise of the Class D Warrants have been duly
authorized and reserved for issuance and, upon issuance in accordance with the
terms of the Class D Warrants, will be validly issued, fully paid and
nonassessable. No stockholder of the Company is entitled to exercise any
preemptive rights in connection with the issuance of such shares of Common
Stock.

            3.15  Rights Agreement. Assuming the accuracy of the representation
and warranty of each of the Investors in Section 4.10 of this Agreement, the
execution, delivery and performance of this Agreement by the parties hereto will
not result in any Investor becoming an Acquiring Person (as such term is defined
in the Rights Agreement, dated as of April 29, 1994,

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between the Company and American Stock Transfer & Trust Company, as Rights
Agent).

            3.16  Exemption from Registration. Assuming the accuracy of the
representations and warranties of each Investor set forth in Sections 4.04
through 4.08 of this Agreement, the offer and sale of the Units to each Investor
will be exempt from registration under the Securities Act of 1933, as amended
(the "1933 Act").

            3.17  Brokerage. There are no claims for brokerage commissions,
finders' fees or similar compensation in connection with the transactions
contemplated by this Agreement based on any agreement or arrangement binding
upon the Company.

            Section 4. Representations and Warranties of the Investors. Each of
the Investors hereby, severally and not jointly, represents and warrants to the
Company as follows:

            4.01. Organization. If the Investor is a corporation, it is duly
organized, validly existing and in good standing under the laws of the
jurisdiction of its incorporation, and if the Investor is a partnership or other
organization, it is duly organized, validly existing and in good standing under
the laws of its jurisdiction of organization.

            4.02. Authorization; No Breach. (i) If the Investor is a
corporation, the execution, delivery and performance of this Agreement, the
Registration Rights Agreement and the Warrant Agreement have been duly
authorized by all necessary corporate action, (ii) if the Investor is a
partnership or other organization, the Investor is permitted under its
partnership agreement or other governing documents to enter into this Agreement,
the Registration Rights Agreement and the Warrant Agreement and to consummate
the transactions contemplated hereby and thereby, and all necessary consents and
approvals required by the partnership agreement or other governing documents
have been obtained, and (iii) this Agreement constitutes, and upon the execution
and delivery thereof by the parties thereto, each of the Registration Rights
Agreement and the Warrant Agreement will constitute, a legal, valid and binding
agreement of the Investor that is enforceable against the Investor in accordance
with its terms, except to the extent that enforceability may be limited by
applicable bankruptcy, insolvency, reorganization, moratorium and similar laws
affecting creditors' rights generally.

            4.03. No Conflicts. The execution, delivery and performance of this
Agreement, the Registration Rights Agreement and the Warrant Agreement do and
will not (i) violate any provision of the Investor's Certificate of
Incorporation or Bylaws (or comparable organizational documents), if the
Investor is a corporation, or the Investor's partnership agreement or other
governing documents, if the Investor is a partnership or other organization,
(ii) violate or breach any material contract or agreement to which the Investor
is a party, or (iii) violate, or require the authorization, consent or approval
of any court or any administrative or governmental body under, any law, statute,
rule or regulation to which the Investor is subject or any order, judgment or
decree by which the Investor is bound.

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            4.04. Accredited Investor. The Investor is an "accredited investor"
as defined in Rule 501 of Regulation D under the 1933 Act. The Investor has
knowledge and experience in financial and business matters such that the
Investor is capable of evaluating the merits and risks of an investment in the
Unit Shares and Class D Warrants.

            4.05. Receipt of Information. The Investor (i) has received a copy
of the Private Placement Memorandum and has reviewed each of the documents
included as part thereof, (ii) has been given the opportunity to obtain from the
Company and to review each of the contracts and other documents that have been
filed with the SEC as exhibits to the filings included as part of the Private
Placement Memorandum, (iii) has been furnished with all such additional
information as the Investor has deemed necessary to make an informed investment
decision with respect to the Unit Shares and Class D Warrants and (iv) has been
afforded an opportunity to ask questions and receive answers from authorized
officers of the Company concerning the Company and the terms and conditions of
the offering of the Unit Shares and Class D Warrants.

            4.06. Awareness of Risks. The Investor is aware that an investment
in the Unit Shares and Class D Warrants is highly speculative and subject to
substantial risks. The Investor is capable of bearing the economic risks of an
investment in the Unit Shares and Class D Warrants including, but not limited
to, the possibility of a complete loss of the Investor's investment, as well as
limitations on the transferability of the Unit Shares and Class D Warrants,
which may make the liquidation of an investment in the securities difficult or
impossible for the indefinite future.

            4.07. Purchases for Investment. The Unit Shares and Class D Warrants
are being acquired solely for investment, and are not being purchased with a
view to a distribution or resale thereof otherwise than in compliance with the
1933 Act.

            4.08. Restrictions on Transfer. The Investor understands that none
of the Unit Shares, the Class D Warrants or the shares of Common Stock issuable
upon the exercise of the Class D Warrants have been registered under the 1933
Act, or any state securities laws, in reliance upon exemptions from registration
for non-public offerings. The Investor agrees that none of the Unit Shares, the
Class D Warrants or the shares of Common Stock issuable upon the exercise of the
Class D Warrants will be resold or otherwise transferred by the Investor unless
such securities have been registered under the 1933 Act and under appropriate
state securities laws or unless the Company receives an opinion of counsel
reasonably satisfactory to it that an exemption from registration is applicable.

            4.09  Brokerage. There are no claims for brokerage commissions,
finders' fees or similar compensation in connection with the transactions
contemplated by this Agreement based on any agreement or arrangement binding
upon the Investor.

            4.10  Beneficial Ownership. After giving effect to the purchase of
the Units, neither the Investor, nor any group (with the meaning of Section
13(d)(3) of the 1934 Act) of which the Investor is a member, will be the
beneficial owner of more than 25% of the then-outstanding shares of Common

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Stock (calculated in the manner provided for in Rule 13d-3 under the 1934 Act).

            Section 5.  Termination.

            5.01  Termination of Agreement.  The parties hereto may terminate
this Agreement as provided below:

            (a)   Any individual Investor and the Company may terminate this
Agreement as between that Investor and the Company by mutual written consent at
any time prior to the Closing.

            (b)   Any individual Investor may terminate this Agreement as
between that Investor and the Company, by giving written notice to the Company
at any time prior to the Closing, in the event the Company is in breach of any
representation, warranty or covenant contained in this Agreement in any material
respect.

            (c)   The Company may terminate this Agreement as between itself and
an individual Investor, by giving written notice to the Investor at any time
prior to the Closing, in the event the Investor is in breach of any
representation, warranty or covenant contained in this Agreement in any material
respect.

            (d)   Any individual Investor may terminate this Agreement as
between that Investor and the Company, by giving written notice to the Company
at any time prior to the Closing, if the Closing shall not have occurred on or
before the 30th day following the date of this Agreement.

            (e)   The Company may terminate this Agreement as between itself and
an individual Investor, by giving written notice to the Investor at any time
prior to the Closing if the Closing, shall not have occurred on or before the
30th day following the date of this Agreement.

            5.02  Effect of Termination. If any party hereto terminates this
Agreement pursuant to Section 5.01, all obligations hereunder of the terminating
party, and of the other party to the terminating party, shall terminate and such
parties shall be released from all of their respective obligations hereunder.

            Section 6   Right of First Refusal.

            The Company hereby covenants as follows:

            (a)   The Company shall not issue any debt or equity securities for
cash in private capital raising transactions (a "Future Offering") within the
three-year period after the date of the Closing ("Closing Date") without
delivering to the Investors prior written notice of its intent to conduct a
Future Offering (a "Future Offering Notice") setting forth the material terms of
the proposed Future Offering, including copies of all relevant documents and
agreements. For a period of twenty days, commencing on the date of receipt of
such Future Offering Notice (the "Offer Period"), each Investor shall have the
right irrevocably to commit, by written notice to the Company, to purchase the
Investor's Portion (as that term is defined below) of the

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securities being offered in the Future Offering on the terms contained in the
Future Offering Notice. If, during the Offer Period, the Investor fails
irrevocably to commit to purchase the Investor's Portion of the securities that
are the subject of the Future Offering Notice, the Company shall be permitted to
offer and sell any such securities, on terms generally no less favorable to the
Company than are set forth in the Future Offering Notice, to any third party
during a period of 90 days following the termination of the Offer Period, after
which 90-day period the terms of this Section 6 shall again apply.

            (b)   The provision of paragraph (a) shall not apply to (i) any
transaction involving the Company's commercial banking arrangements, (ii) the
issuance of securities in connection with a merger, consolidation or sale of
assets, or in connection with a joint venture or an acquisition or disposition
of a business, a product or a license by the Company, or (iii) to the issuance
of securities to any employee, officer, director or consultant.

            (c)   The amount of securities that an Investor is entitled to
purchase in a Future Offering (the "Investor's Portion") shall be the number
obtained by multiplying the aggregate amount of securities being offered in the
Future Offering by a fraction, the numerator of which is the number of Units
purchased by the Investor pursuant to this Agreement (whether or not the
Investor continues to own the Unit Shares or the Warrants) and the denominator
of which is the number of Units purchased by all Investors pursuant to this
Agreement.

            (d)   The rights of each Investor under this Section 6 shall not be
transferable or assignable by the Investor without the prior written consent of
the Company.

            Section 7   Transfer Restrictions on Common Stock.

            7.01   The Company shall be under no obligation to effect the
transfer of the Unit Shares unless the holder thereof shall deliver written
notice to the Company describing in reasonable detail the proposed transfer and,
in the case of a transfer that is effected other than pursuant to an effective
registration statement under the 1933 Act or pursuant to Rule 144, an agreement
in writing of the transferee to be bound by the restrictions on transfer set
forth in this Section 7. For so long as the Unit Shares are Restricted
Securities, the holder also shall deliver to the Company an opinion of counsel,
in form and substance reasonably satisfactory to the Company, to the effect that
such transfer may be effected without registration under the 1933 Act.

            7.02  For so long as any shares of Common Stock issuable upon the
exercise of the Class D Warrants are Restricted Securities, the Company shall
not be obligated to effect any transfer thereof unless the holder shall deliver
to the Company an opinion of counsel, in form and substance reasonably
satisfactory to the Company, to the effect that such transfer can be effected
without registration under the 1933 Act.

            7.03  If at any time a holder of Unit Shares or shares of Common
Stock issued upon the exercise of the Class D Warrants delivers to the Company
an opinion of counsel, in form and substance reasonably satisfactory to the


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Company, that such shares of Common Stock are eligible for resale by the holder
thereof pursuant to Rule 144(k) under the 1933 Act, the Company shall, upon
surrender of the legended certificates, deliver to the holder new certificates
for such shares of Common Stock that do not bear the legend set forth in Section
9.02.

            Section 8.  Definitions.  For the purpose of this Agreement, the
following terms have the meanings set forth below:

            "1933 Act" has the meaning set forth in section 3.17.

            "1934 Act" has the meaning set forth in Section 3.05.

            "Class D Warrants" has the meaning set forth in Section 1.01.

            "Closing" has the meaning set forth in Section 1.03.

            "Common Stock" has the meaning set forth in Section 1.01.

            "Company" has the meaning set forth in the Preamble.

            "Company Financial Statements" has the meaning set forth in
Section 3.04.

            "Company Interim Financial Statements" has the meaning set forth
in Section 3.04.

            "Investor" has the meaning set forth in the Preamble.

            "Material Adverse Effect" means, with respect to the Company, a
material adverse effect on the business, properties, assets, condition
(financial or other), results of operations or prospects of the Company.

            "Person" means an individual, a partnership, a corporation, an
association, a joint stock company, a trust, a joint venture, an unincorporated
organization and a governmental entity or any department, agency or political
subdivision thereof.

            "Registration Rights Agreement" has the meaning set forth in
Section 2.03.

            "Restricted Securities" means (i) the Unit Shares hereunder; (ii)
the shares of Common Stock issued upon the exercise of the Class D Warrants; and
(iii) any securities issued with respect to the securities referred to in clause
(i) or (ii) above by way of a stock dividend or stock split or in connection
with a combination of shares, recapitalization, merger, consolidation or other
reorganization. As to any particular Restricted Securities, such securities
shall cease to be Restricted Securities when they have (A) been sold pursuant to
an effective registration statement under the 1933 Act or (B) become eligible
for sale pursuant to Rule 144 (or any similar provision then in force) under the
1933 Act.

            "SEC" has the meaning set forth in Section 3.05.

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            "SEC Filings" means (i) the Annual Report of the Company on Form
10-K for the year ended December 31, 1995, (ii) the Quarterly Reports of the
Company on Form 10-Q for the quarters ended March 31, June 30, and September 30,
1996, and (iii) any Form 8-K filed by the Company since December 31, 1995.

            "Unit Shares" has the meaning set forth in Section 1.01.

            "Warrant Agreement" has the meaning set forth in Section 2.04.

            Section 9.  Miscellaneous.

            9.01  Certain Expenses. The Company agrees to pay, and hold the
Investors harmless against liability for the payment of, stamp and other similar
taxes which may be payable in respect of (i) the execution and delivery of this
Agreement, the Registration Rights Agreement and the Warrant Agreement, (ii) the
issuance, sale and delivery of the shares of Common Stock and Class D Warrants
comprising the Units, and (iii) the issuance, sale and delivery to a holder of
Class D Warrants of the shares of Common Stock issued upon the exercise of the
Class D Warrants. The Company agrees to pay or reimburse Roger H. Samet for up
to $7,000 in legal fees and disbursements incurred in connection with the
purchase of the Units and in connection with any legal opinions with respect to
the application of the 1933 Act that are required to effect a transfer of the
shares of Common Stock and Class D Warrants comprising the Units or the shares
of Common Stock issued upon the exercise of the Class D Warrants.

            9.02  Securities Legend.

            Each certificate for Unit Shares and each certificate for shares of
Common Stock issued upon the exercise of the Class D Warrants shall be imprinted
with a legend in substantially the following form for so long as such shares
continue to be Restricted Securities:

            "THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
            REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT
            BE OFFERED FOR SALE, SOLD OR OTHERWISE TRANSFERRED, OTHER THAN IN
            ACCORDANCE WITH AN EFFECTIVE REGISTRATION STATEMENT UNDER SAID ACT
            OR PURSUANT TO AN EXEMPTION FROM REGISTRATION."

            9.03  Amendments. The provisions of this Agreement may be amended
only with the written consent of the Company and each Investor. No other course
of dealing between the Company and any Investor or any delay in exercising any
rights hereunder shall operate as a waiver of any rights of an Investor or the
Company.

            9.04  Survival of Representation and Warranties. All representations
and warranties contained herein shall survive the execution and delivery of this
Agreement and the consummation of the transactions contemplated hereby for a
period of three years after the Closing.

            9.05  Successors and Assigns. This Agreement and the rights and
obligations hereunder may not be assigned by either party hereto (by operation
of law or otherwise) without the prior written consent of the other.

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            9.06  Severability. Whenever possible, each provision of this
Agreement shall be interpreted in such manner as to be effective and valid under
applicable law, but if any provision of this Agreement is held to be prohibited
by or invalid under applicable law, such provision shall be ineffective only to
the extent of such prohibition or invalidity, and to the extent permitted by law
shall not invalidate the remainder of this Agreement.

            9.07  Counterparts. This Agreement may be executed simultaneously in
two or more counterparts, any one of which need not contain the signatures of
more than one party, but all such counterparts taken together shall constitute
one and the same Agreement.

            9.08  Descriptive Headings; Interpretation. The descriptive headings
of this Agreement are inserted for convenience only and shall not affect the
meaning of this Agreement. The use of the word "including" in this Agreement
shall be by way of example rather than by limitation.

            9.09  Governing law. This Agreement shall be governed by and
construed in accordance with the laws of the state of Maryland without giving
effect to any choice of law or conflict of law provision.

            9.10  Notices.

            (a)   All notices, requests, demands, claims and other
communications hereunder will be in writing and shall be made by hand-delivery,
certified mail, return receipt requested, overnight or two-day courier, or
facsimile transmission, addressed to the intended recipient as set forth below:

            If to the Company:

            Alpha 1 Biomedicals, Inc.
            6707 Democracy Boulevard
            Suite 111
            Bethesda, MD  20817-1129
            Facsimile Number: (301) 564-4424

            Copy (which shall not constitute notice) to:

            Covington & Burling
            1201 Pennsylvania Avenue, N.W.
            Washington, D.C.  20044
            Attn:  Michael Lefever
            Facsimile Number: (202) 778-5276

            If to the Investors:

            To the address set forth on Schedule 1

Each party hereto may change the address for such communication by notice to the
other party (to the Company in the case of each Investor and to the Investor in
the case of the Company) in the manner contemplated hereby.

                                       70
<PAGE>   13

            (b)   All such notices, requests, demands, claims and other
communications shall be deemed to have been duly given (i) when delivered by
hand, if personally delivered, (ii) five days after being deposited in the mail,
if mailed, (iii) upon receipt, if sent by overnight or two day courier and (iv)
upon receipt, if sent by facsimile transmission, except in the case of Roger H.
Samet, no notice, request, demand, claim or other communication shall be deemed
given unless (x) actually received by Roger H. Samet or (y) given in the manner
provided above to the person to whom copies are to be delivered.

            9.11  Entire Agreement. This Agreement, together with the
Registration Rights Agreement and the Warrant Agreement, constitutes the entire
agreement of the parties hereto with respect to the subject matter thereof and
supersedes all prior agreements of the parties with respect to such subject
matter.



                                       71
<PAGE>   14



            IN WITNESS WHEREOF, the parties hereto have executed this Agreement
on the date first written above.

                                          ALPHA 1 BIOMEDICALS,
                                            INC.

                                    By    /s/ Michael L. Berman
                                      -----------------------------
                                          Michael Berman
                                          President and Chief
                                            Executive Officer



                                          /s/ Roger H. Samet
                                    ------------------------------------
                                    ROGER H. SAMET



                                          /s/ Joseph C. McNay
                                    ------------------------------------
                                    JOSEPH C. MCNAY


                                          /s/ Stephen C. Lampl
                                    ------------------------------------
                                    STEPHEN C. LAMPL
                                    ANNE B. SHUMADINE TTEE V/A
                                    STEPHEN C. LAMPL TRUST DTD 4/16/87


                                          /s/ C.L. Kaufman, Jr.
                                    ------------------------------------
                                    C. L. KAUFMAN, JR.


                                          /s/ Michael L. Berman
                                    ------------------------------------
                                    MICHAEL L. BERMAN


                                          /s/ R.J. Lanham
                                    ------------------------------------
                                    R.J. LANHAM



                                       72
<PAGE>   15

                                                                      SCHEDULE 1


<TABLE>
<CAPTION>

Name of Investor                    Number of          Total Purchase    Number of      Number of
----------------                      Units                Price          Shares         Warrants
                                   -----------         --------------   -----------      --------
<S>                                   <C>                <C>             <C>             <C>
Roger H. Samet                        1.77               $ 88,500         885,000        292,050
254 E. 68th Street
Apt. 29B
New York, NY  10021

with copies of notices to Samet to:

Stephen B. Silverman, Esq.
Corbin, Silverman
& Sanseverino LLP
805 3rd Avenue
New York, NY  10022

Joseph C. McNay                       1.00               $  50,000        500,000        165,000
Essex Investment
Management Co.
125 High Street 25th Floor
Boston,  MA  02110-2702

Stephen C. Lampl Trust                0.50               $  25,000        250,000         82,500
Anne B. Shumadine TTEE
370 Edgemore Way North
Naples,  FL  34105

Charles Kaufman, Jr.                  0.50               $  25,000        250,000         82,500
P.O. Box 13495
Chesapeake, VA  23325

Michael L. Berman                     0.13               $  6,500          65,000         21,450
8824 Watts Mine Terrace
Potomac,  MD  20854

Robert J. Lanham                      0.10               $  5,000          50,000         16,500
2014 Gunnell Farms Drive
Vienna, VA  22181                  ---------             ----------     ---------        -------

Total                                 4.00               $  200,000     2,000,000        660,000
</TABLE>



                                       73
<PAGE>   16


                                                                      SCHEDULE 2

                         OUTSTANDING OPTIONS/WARRANTS

           Shares of Alpha 1 Common Stock Reserved and Issuable(1)


                                         Shares Reserved
                                          for Outstanding
                                       Options and Warrants

                              ---------------------------------------

Incentive Stock Option Plan                 1,053,433
Non-qualified Option Plan                     685,360
Directors Option Plan                          40,000
Hammond Warrants (2)                           20,000
Total Reserved                              ---------
                                            1,798,793



(1)  as of March 1, 1997
(2)  Warrants expire on February 2, 1998




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