Document:

Exhibit 10.2

NEITHER THESE  SECURITIES  NOR THE  SECURITIES  INTO WHICH THESE  SECURITIES ARE
EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE  COMMISSION OR
THE  SECURITIES  COMMISSION  OF ANY STATE IN  RELIANCE  UPON AN  EXEMPTION  FROM
REGISTRATION  UNDER THE  SECURITIES  ACT OF 1933,  AS AMENDED  (THE  "SECURITIES
ACT"),  AND,  ACCORDINGLY,  MAY NOT BE OFFERED  OR SOLD  EXCEPT  PURSUANT  TO AN
EFFECTIVE  REGISTRATION  STATEMENT  UNDER THE  SECURITIES  ACT OR PURSUANT TO AN
AVAILABLE  EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE  REGISTRATION
REQUIREMENTS  OF THE  SECURITIES  ACT AND IN ACCORDANCE  WITH  APPLICABLE  STATE
SECURITIES  LAWS AS EVIDENCED BY A LEGAL OPINION OF COUNSEL TO THE TRANSFEROR TO
SUCH  EFFECT,  THE  SUBSTANCE  OF WHICH SHALL BE  REASONABLY  ACCEPTABLE  TO THE
COMPANY.  THESE  SECURITIES AND THE  SECURITIES  ISSUABLE UPON EXERCISE OF THESE
SECURITIES MAY BE PLEDGED IN CONNECTION  WITH A BONA FIDE MARGIN ACCOUNT SECURED
BY SUCH SECURITIES.

                           HEMISPHERX BIOPHARMA, INC.

                                     WARRANT

Warrant No. ___                        Date of Original Issuance: August 5, 2004

      Hemispherx Biopharma, Inc., a Delaware corporation (the "Company"), hereby
certifies that, for value received, __________ or its registered assigns (the
"Holder"), is entitled to purchase from the Company up to a total of _________
shares of common stock, $.001 par value (the "Common Stock"), of the Company
(each such share, a "Warrant Share" and all such shares, the "Warrant Shares")
at an exercise price equal to $2.86 per share (as adjusted from time to time as
provided in Section 9, the "Exercise Price"), at any time and from time to time
from and after the date hereof and through and including the fifth year
anniversary of the issuance date hereof (the "Expiration Date"), and subject to
the following terms and conditions:

      This Warrant is one of a series of warrants issued pursuant to that
certain Securities Purchase Agreement of even date herewith to which the Company
and the original Holder are parties (the "Purchase Agreement").

      1. Definitions. In addition to the terms defined elsewhere in this
Warrant, capitalized terms that are not otherwise defined herein shall have the
meanings given to such terms in the Purchase Agreement.

      2. Registration of Warrant. The Company shall register this Warrant, upon
records to be maintained by the Company for that purpose (the "Warrant
Register"), in the name of the record Holder hereof from time to time. The
Company may deem and treat the registered Holder of this Warrant as the absolute
owner hereof for the purpose of any exercise hereof or any distribution to the
Holder, and for all other purposes, absent actual notice to the contrary.

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      3. Registration of Transfers. The Company shall register the transfer of
any portion of this Warrant in the Warrant Register, upon surrender of this
Warrant, with the Form of Assignment attached hereto duly completed and signed,
to the Company at its address specified herein. Upon any such registration or
transfer, a new Warrant to purchase Common Stock, in substantially the form of
this Warrant (any such new Warrant, a "New Warrant"), evidencing the portion of
this Warrant so transferred shall be issued to the transferee and a New Warrant
evidencing the remaining portion of this Warrant not so transferred, if any,
shall be issued to the transferring Holder. The acceptance of the New Warrant by
the transferee thereof shall be deemed the acceptance by such transferee of all
of the rights and obligations of a holder of a Warrant. Notwithstanding the
foregoing, this Warrant is subject to the transfer restrictions set forth in
Section 4.1 of the Purchase Agreement.

      4. Exercise and Duration of Warrants.

            (a) This Warrant shall be exercisable by the registered Holder at
any time and from time to time on or after the date hereof to and including the
Expiration Date. Subject to Section 11, at 5:00 p.m., New York time on the
Expiration Date, the portion of this Warrant not exercised prior thereto shall
be and become void and of no value.

            (b) Subject to the provisions of this Section 4(b), at any time
after the first anniversary of the Closing Date, if the: (i) VWAP (as defined
below) of the Common Stock for any thirty (30) consecutive Trading Days after
such first anniversary of the Closing Date is greater than $5.00 (as may be
adjusted pursuant to Section 9), (ii) the Warrant Shares are either registered
for resale pursuant to an effective registration statement naming the Holder as
a selling stockholder thereunder (and the prospectus thereunder is available for
use by the Holder as to all then available Warrant Shares) or freely
transferable without volume restrictions pursuant to Rule 144(k) promulgated
under the Securities Act, as determined by counsel to the Company pursuant to a
written opinion letter addressed and in form and substance reasonably acceptable
to the Holder and the transfer agent for the Common Stock, and (iii) the Company
shall have fully honored in accordance with the terms of this Warrant all
Exercise Notices delivered prior to 5:00 p.m. (New York time) on the Call Date
(as defined below), then the Company may, subject to Section 11, require cash
exercise pursuant to Section 10(a) hereof of all, but not less than all, of the
portion of this Warrant for which Exercise Notices have not been delivered by
5:00 p.m. on the Call Date. To exercise this right, the Company must deliver to
the Holder an irrevocable written notice (a "Call Notice"), indicating therein
that this Warrant shall be exercised. If the conditions for such Call are
satisfied from the period from the date of the Call Notice through and including
the Call Date, then, subject to Section 11, this Warrant shall be deemed to have
been exercised in full on a cash basis pursuant to Section 10(a) hereof at 5:00
p.m. (New York time) on the tenth Trading Day after the date the Call Notice is
received by the Holder (such date, the "Call Date"). The Holder shall deliver
payment in immediately available funds of the Exercise Price for the number of
Warrant Shares for which this Warrant is required to be exercised under this
subsection promptly but in any event no later than ten business days following
the Call Date. The Company covenants and agrees that it will honor all Forms of
Election to Purchase with respect to Warrant Shares that are tendered from the
time of delivery of the Call Notice through 5:00 p.m. (New York time) on the
Call Date. "VWAP" means on any particular Trading Day or for any particular
period, the volume weighted average trading price

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per share of Common Stock on such date or for such period as reported by
Bloomberg L.P., or any successor performing similar functions. The Company and
the Holder agree that, if and to the extent Section 11 of this Warrant would
restrict the ability of the Holder to exercise this Warrant in full in the event
of a delivery of a Call Notice, then notwithstanding anything to the contrary
set forth in the Call Notice, the Call Notice shall be deemed automatically
amended to apply only to such portion of this Warrant as may be exercised by the
Holder by the Call Date in accordance with Section 11. The Holder will promptly
(and, in any event, prior to the Call Date) notify the Company in writing
following receipt of a Call Notice if Section 11 would restrict its exercise of
the Warrant, specifying therein the number of Warrant Shares so restricted.

      5. Delivery of Warrant Shares.

            (a) To effect exercises hereunder, the Holder shall not be required
to physically surrender this Warrant unless the aggregate Warrant Shares
represented by this Warrant is being exercised. Upon delivery of the Exercise
Notice to the Company (with the attached Warrant Shares Exercise Log) at its
address for notice set forth herein and upon payment of the Exercise Price
multiplied by the number of Warrant Shares that the Holder intends to purchase
hereunder, the Company shall promptly (but in no event later than three Trading
Days after the Date of Exercise (as defined herein)) issue and deliver to the
Holder, a certificate for the Warrant Shares issuable upon such exercise, which,
provided that there is an effective registration statement covering the sale of
such Warrant Shares and unless otherwise required by the Purchase Agreement,
shall be free of restrictive legends. The Company shall, upon request of the
Holder and subsequent to the date on which a registration statement covering the
resale of the Warrant Shares has been declared effective by the Securities and
Exchange Commission, use its best efforts to deliver Warrant Shares hereunder
electronically through the Depository Trust Corporation or another established
clearing corporation performing similar functions, if available, provided, that,
the Company may, but will not be required to change its transfer agent if its
current transfer agent cannot deliver Warrant Shares electronically through the
Depository Trust Corporation. A "Date of Exercise" means the date on which the
Holder shall have delivered to Company: (i) the Exercise Notice (with the
Warrant Exercise Log attached to it), appropriately completed and duly signed
and (ii) if such Holder is not utilizing the cashless exercise provisions set
forth in this Warrant, payment of the Exercise Price for the number of Warrant
Shares so indicated by the Holder to be purchased.

            (b) If by the third Trading Day after a Date of Exercise the Company
fails to deliver the required number of Warrant Shares in the manner required
pursuant to Section 5(a), then the Holder will have the right to rescind such
exercise.

            (c) If by the fifth Trading Day after a Date of Exercise the Company
fails to deliver the required number of Warrant Shares in the manner required
pursuant to Section 5(a), and if after such fifth Trading Day and prior to the
receipt of such Warrant Shares, the Holder purchases (in an open market
transaction or otherwise) shares of Common Stock to deliver in satisfaction of a
sale by the Holder of the Warrant Shares which the Holder anticipated receiving
upon such exercise (a "Buy In"), then the Company shall (1) pay in cash to the
Holder the amount by which (x) the Holder's total purchase price (including
brokerage commissions, if any) for the shares of Common Stock so purchased
exceeds (y) the amount obtained by

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multiplying (A) the number of Warrant Shares that the Company was required to
deliver to the Holder in connection with the exercise at issue by (B) the
closing bid price of the Common Stock at the time of the obligation giving rise
to such purchase obligation and (2) at the option of the Holder, either
reinstate the portion of the Warrant and equivalent number of Warrant Shares for
which such exercise was not honored or deliver to the Holder the number of
shares of Common Stock that would have been issued had the Company timely
complied with its exercise and delivery obligations hereunder. The Holder shall
provide the Company written notice indicating the amounts payable to the Holder
in respect of the Buy In.

            (d) The Company's obligations to issue and deliver Warrant Shares in
accordance with the terms hereof are absolute and unconditional, irrespective of
any action or inaction by the Holder to enforce the same, any waiver or consent
with respect to any provision hereof, the recovery of any judgment against any
Person or any action to enforce the same, or any setoff, counterclaim,
recoupment, limitation or termination, or any breach or alleged breach by the
Holder or any other Person of any obligation to the Company or any violation or
alleged violation of law by the Holder or any other Person, and irrespective of
any other circumstance which might otherwise limit such obligation of the
Company to the Holder in connection with the issuance of Warrant Shares. Nothing
herein shall limit a Holder's right to pursue any other remedies available to it
hereunder, at law or in equity including, without limitation, a decree of
specific performance and/or injunctive relief with respect to the Company's
failure to timely deliver certificates representing shares of Common Stock upon
exercise of the Warrant as required pursuant to the terms hereof.

      6. Charges, Taxes and Expenses. Issuance and delivery of certificates for
shares of Common Stock upon exercise of this Warrant shall be made without
charge to the Holder for any issue or transfer tax, transfer agent fee or other
incidental tax or expense in respect of the issuance of such certificates, all
of which taxes and expenses shall be paid by the Company; provided, however,
that the Company shall not be required to pay any tax which may be payable in
respect of any transfer involved in the registration of any certificates for
Warrant Shares or Warrants in a name other than that of the Holder. The Holder
shall be responsible for all other tax liability that may arise as a result of
holding or transferring this Warrant or receiving Warrant Shares upon exercise
hereof.

      7. Replacement of Warrant. If this Warrant is mutilated, lost, stolen or
destroyed, the Company shall issue or cause to be issued in exchange and
substitution for and upon cancellation hereof, or in lieu of and substitution
for this Warrant, a New Warrant, but only upon receipt of evidence reasonably
satisfactory to the Company of such loss, theft or destruction and customary and
reasonable indemnity (which shall not include a surety bond), if requested.
Applicants for a New Warrant under such circumstances shall also comply with
such other reasonable regulations and procedures and pay such other reasonable
third-party costs as the Company may prescribe. If a New Warrant is requested as
a result of a mutilation of this Warrant, then the Holder shall deliver such
mutilated Warrant to the Company as a condition precedent to the Company's
obligation to issue the New Warrant.

      8. Reservation of Warrant Shares. The Company covenants that it will at
all times reserve and keep available out of the aggregate of its authorized but
unissued and

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otherwise unreserved Common Stock, solely for the purpose of enabling it to
issue Warrant Shares upon exercise of this Warrant as herein provided, the
number of Warrant Shares which are then issuable and deliverable upon the
exercise of this entire Warrant, free from preemptive rights or any other
contingent purchase rights of persons other than the Holder (taking into account
the adjustments and restrictions of Section 9). The Company covenants that all
Warrant Shares so issuable and deliverable shall, upon issuance and the payment
of the applicable Exercise Price in accordance with the terms hereof, be duly
and validly authorized, issued and fully paid and nonassessable.

      9. Certain Adjustments. The Exercise Price and number of Warrant Shares
issuable upon exercise of this Warrant are subject to adjustment from time to
time as set forth in this Section 9.

            (a) Stock Dividends and Splits. If the Company, at any time while
this Warrant is outstanding, (i) pays a stock dividend on its Common Stock or
otherwise makes a distribution on any class of capital stock that is payable in
shares of Common Stock, (ii) subdivides outstanding shares of Common Stock into
a larger number of shares, or (iii) combines outstanding shares of Common Stock
into a smaller number of shares, then in each such case the Exercise Price shall
be multiplied by a fraction of which the numerator shall be the number of shares
of Common Stock outstanding immediately before such event and of which the
denominator shall be the number of shares of Common Stock outstanding
immediately after such event. Any adjustment made pursuant to clause (i) of this
paragraph shall become effective immediately after the record date for the
determination of stockholders entitled to receive such dividend or distribution,
and any adjustment pursuant to clause (ii) or (iii) of this paragraph shall
become effective immediately after the effective date of such subdivision or
combination. If any event requiring an adjustment under this paragraph occurs
during the period that an Exercise Price is calculated hereunder, then the
calculation of such Exercise Price shall be adjusted appropriately to reflect
such event.

            (b) Pro Rata Distributions. If the Company, at any time while this
Warrant is outstanding, distributes to all holders of Common Stock (i) evidences
of its indebtedness, (ii) any security (other than a distribution of Common
Stock covered by the preceding paragraph), (iii) rights or warrants to subscribe
for or purchase any security, or (iv) any other asset (in each case,
"Distributed Property"), then, at the request of any Holder delivered before the
90th day after the record date fixed for determination of stockholders entitled
to receive such distribution, the Company will deliver to such Holder, within
five Trading Days after such request (or, if later, on the effective date of
such distribution), the Distributed Property that such Holder would have been
entitled to receive in respect of the Warrant Shares for which such Holder's
Warrant could have been exercised immediately prior to such record date. If such
Distributed Property is not delivered to a Holder pursuant to the preceding
sentence, then upon any exercise of the Warrant that occurs after such record
date, such Holder shall be entitled to receive, in addition to the Warrant
Shares otherwise issuable upon such conversion, the Distributed Property that
such Holder would have been entitled to receive in respect of such number of
Warrant Shares had the Holder been the record holder of such Warrant Shares
immediately prior to such record date.

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            (c) Fundamental Transactions. If, at any time while this Warrant is
outstanding, (1) the Company effects any merger or consolidation of the Company
with or into another Person, (2) the Company effects any sale of all or
substantially all of its assets in one or a series of related transactions, (3)
any tender offer or exchange offer (whether by the Company or another Person) is
completed pursuant to which holders of Common Stock are permitted to tender or
exchange their shares for other securities, cash or property, or (4) the Company
effects any reclassification of the Common Stock or any compulsory share
exchange pursuant to which the Common Stock is effectively converted into or
exchanged for other securities, cash or property (in any such case, a
"Fundamental Transaction"), then the Holder shall have the right thereafter to
receive, upon exercise of this Warrant, the same amount and kind of securities,
cash or property as it would have been entitled to receive upon the occurrence
of such Fundamental Transaction if it had been, immediately prior to such
Fundamental Transaction, the holder of the number of Warrant Shares then
issuable upon exercise in full of this Warrant (the "Alternate Consideration").
For purposes of any such exercise, the determination of the Exercise Price shall
be appropriately adjusted to apply to such Alternate Consideration based on the
amount of Alternate Consideration issuable in respect of one share of Common
Stock in such Fundamental Transaction, and the Company shall apportion the
Exercise Price among the Alternate Consideration in a reasonable manner
reflecting the relative value of any different components of the Alternate
Consideration. If holders of Common Stock are given any choice as to the
securities, cash or property to be received in a Fundamental Transaction, then
the Holder shall be given the same choice as to the Alternate Consideration it
receives upon any exercise of this Warrant following such Fundamental
Transaction. At the Holder's request, any successor to the Company or surviving
entity in such Fundamental Transaction shall, issue to the Holder a new warrant
substantially in the form of this Warrant and consistent with the foregoing
provisions and evidencing the Holder's right to purchase the Alternate
Consideration for the aggregate Exercise Price upon exercise thereof.. The terms
of any agreement pursuant to which a Fundamental Transaction is effected shall
include terms requiring any such successor or surviving entity to comply with
the provisions of this paragraph (c) and insuring that the Warrant (or any such
replacement security) will be similarly adjusted upon any subsequent transaction
analogous to a Fundamental Transaction.

            (d) Number of Warrant Shares. Simultaneously with any adjustment to
the Exercise Price pursuant to paragraphs (a) of this Section, the number of
Warrant Shares that may be purchased upon exercise of this Warrant shall be
increased or decreased proportionately, so that after such adjustment the
aggregate Exercise Price payable hereunder for the adjusted number of Warrant
Shares shall be the same as the aggregate Exercise Price in effect immediately
prior to such adjustment.

            (e) Calculations. All calculations under this Section 9 shall be
made to the nearest cent or the nearest 1/100th of a share, as applicable. The
number of shares of Common Stock outstanding at any given time shall not include
shares owned or held by or for the account of the Company, and the disposition
of any such shares shall be considered an issue or sale of Common Stock.

            (f) Notice of Adjustments. Upon the occurrence of each adjustment
pursuant to this Section 9, the Company at its expense will promptly compute
such adjustment in

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<PAGE>

accordance with the terms of this Warrant and prepare a certificate setting
forth such adjustment, including a statement of the adjusted Exercise Price and
adjusted number or type of Warrant Shares or other securities issuable upon
exercise of this Warrant (as applicable), describing the transactions giving
rise to such adjustments and showing in detail the facts upon which such
adjustment is based. Upon written request, the Company will promptly deliver a
copy of each such certificate to the Holder and to the Company's Transfer Agent.

            (g) Notice of Corporate Events. If the Company (i) declares a
dividend or any other distribution of cash, securities or other property in
respect of its Common Stock, including without limitation any granting of rights
or warrants to subscribe for or purchase any capital stock of the Company or any
Subsidiary, (ii) authorizes or approves, enters into any agreement contemplating
or solicits stockholder approval for any Fundamental Transaction or (iii)
authorizes the voluntary dissolution, liquidation or winding up of the affairs
of the Company, then, except if such notice and the contents thereof shall be
deemed to constitute material non-public information, the Company shall deliver
to the Holder a notice describing the material terms and conditions of such
transaction, at least 20 calendar days prior to the applicable record or
effective date on which a Person would need to hold Common Stock in order to
participate in or vote with respect to such transaction, and the Company will
take all steps reasonably necessary in order to insure that the Holder is given
the practical opportunity to exercise this Warrant prior to such time so as to
participate in or vote with respect to such transaction; provided, however, that
the failure to deliver such notice or any defect therein shall not affect the
validity of the corporate action required to be described in such notice. Until
the exercise of this Warrant or any portion of this Warrant, the Holder shall
not have nor exercise any rights by virtue hereof as a stockholder of the
Company (including without limitation the right to notification of stockholder
meetings or the right to receive any notice or other communication concerning
the business and affairs of the Company other than as provided in this Section
9).

      10. Payment of Exercise Price. The Holder may pay the Exercise Price in
one of the following manners:

            (a) Cash Exercise. The Holder may deliver immediately available
funds; or(a)

            (b) Cashless Exercise. Commencing one year after the date of
original issuance of this Warrant, provided that a registration statement
registering the Warrant Shares is not effective on such date, the Holder may
notify the Company in an Exercise Notice of its election to utilize cashless
exercise, in which event the Company shall issue to the Holder the number of
Warrant Shares determined as follows:

                 X = Y [(A-B)/A]

      where:

                 X = the number of Warrant Shares to be issued to the Holder.

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                 Y = the number of Warrant Shares with respect to which this
                 Warrant is being exercised.

                 A = the average of the closing prices for the five Trading Days
                 immediately prior to (but not including) the Exercise Date.

                 B = the Exercise Price.

For purposes of Rule 144 promulgated under the Securities Act, it is intended,
understood and acknowledged that the Warrant Shares issued in a cashless
exercise transaction shall be deemed to have been acquired by the Holder, and
the holding period for the Warrant Shares shall be deemed to have commenced, on
the date this Warrant was originally issued.

      11. Limitation on Exercise. [Investors may individually elect to omit
either or both of clauses (i) and (ii) of this Section 11 upon first issuance of
the Warrant at Closing.]

            (i) [Notwithstanding anything to the contrary contained herein, the
number of shares of Common Stock that may be acquired by the Holder upon any
exercise of this Warrant (or otherwise in respect hereof) shall be limited to
the extent necessary to insure that, following such exercise (or other
issuance), the total number of shares of Common Stock then beneficially owned by
such Holder and its Affiliates and any other Persons whose beneficial ownership
of Common Stock would be aggregated with the Holder's for purposes of Section
13(d) of the Exchange Act, does not exceed 4.999% of the total number of issued
and outstanding shares of Common Stock (including for such purpose the shares of
Common Stock issuable upon such exercise). For such purposes, beneficial
ownership shall be determined in accordance with Section 13(d) of the Exchange
Act and the rules and regulations promulgated thereunder. Each delivery of an
Exercise Notice hereunder will constitute a representation by the Holder that it
has evaluated the limitation set forth in this paragraph and determined that
issuance of the full number of Warrant Shares requested in such Exercise Notice
is permitted under this paragraph. This provision shall not restrict the number
of shares of Common Stock which a Holder may receive or beneficially own in
order to determine the amount of securities or other consideration that such
Holder may receive in the event of a merger or other business combination or
reclassification involving the Company as contemplated in Section 9 of this
Warrant. By written notice to the Company, the Holder may waive the provisions
of this Section but any such waiver will not be effective until the 61st day
after such notice is delivered to the Company.]

            (ii) [Notwithstanding anything to the contrary contained herein, the
number of shares of Common Stock that may be acquired by the Holder upon any
exercise of this Warrant (or otherwise in respect hereof) shall be limited to
the extent necessary to insure that, following such exercise (or other
issuance), the total number of shares of Common Stock then beneficially owned by
such Holder and its Affiliates and any other Persons whose beneficial ownership
of Common Stock would be aggregated with the Holder's for purposes of Section
13(d) of the Exchange Act, does not exceed 9.999% of the total number of issued
and outstanding shares of Common Stock (including for such purpose the shares of
Common Stock issuable upon such exercise). For such purposes, beneficial
ownership shall be determined in accordance with Section 13(d) of the Exchange
Act and the rules and regulations promulgated

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<PAGE>

thereunder. Each delivery of an Exercise Notice hereunder will constitute a
representation by the Holder that it has evaluated the limitation set forth in
this paragraph and determined that issuance of the full number of Warrant Shares
requested in such Exercise Notice is permitted under this paragraph. This
provision shall not restrict the number of shares of Common Stock which a Holder
may receive or beneficially own in order to determine the amount of securities
or other consideration that such Holder may receive in the event of a merger or
other business combination or reclassification involving the Company as
contemplated in Section 9 of this Warrant. This restriction may not be waived.]

      12. No Fractional Shares. No fractional shares of Warrant Shares will be
issued in connection with any exercise of this Warrant. In lieu of any
fractional shares which would, otherwise be issuable, the Company shall pay cash
equal to the product of such fraction multiplied by the closing price of one
Warrant Share as reported by Bloomberg L.P. (or the successor to its function of
reporting share prices) on the date of exercise.

      13. Exchange Act Filings. The Holder agrees and acknowledges that it shall
have sole responsibility for making any applicable filings with the U.S.
Securities and Exchange Commission pursuant to Section 13 and 16 of the
Securities Exchange Act of 1934, as amended, as a result of its acquisition of
this Warrant and the Warrant Shares and any future retention or transfer
thereof.

      14. Notices. Any and all notices or other communications or deliveries
hereunder (including, without limitation, any Exercise Notice) shall be in
writing and shall be deemed given and effective on the earliest of (i) the date
of transmission, if such notice or communication is delivered via facsimile at
the facsimile number specified in this Section prior to 5:00 p.m. (New York
time) on a Trading Day, (ii) the next Trading Day after the date of
transmission, if such notice or communication is delivered via facsimile at the
facsimile number specified in this Section on a day that is not a Trading Day or
later than 5:00 p.m. (New York time) on any Trading Day, (iii) the Trading Day
following the date of mailing, if sent by nationally recognized overnight
courier service, or (iv) upon actual receipt by the party to whom such notice is
required to be given. The addresses for such communications shall be: (i) if to
the Company, to the address set forth in the Purchase Agreement, or (ii) if to
the Holder, to the address or facsimile number appearing on the Warrant Register
or such other address or facsimile number as the Holder may provide to the
Company in accordance with this Section.

      15. Warrant Agent. The Company shall serve as warrant agent under this
Warrant. Upon 30 days' notice to the Holder, the Company may appoint a new
warrant agent. Any corporation into which the Company or any new warrant agent
may be merged or any corporation resulting from any consolidation to which the
Company or any new warrant agent shall be a party or any corporation to which
the Company or any new warrant agent transfers substantially all of its
corporate trust or shareholders services business shall be a successor warrant
agent under this Warrant without any further act. Any such successor warrant
agent shall promptly cause notice of its succession as warrant agent to be
mailed (by first class mail, postage prepaid) to the Holder at the Holder's last
address as shown on the Warrant Register.

      16. Miscellaneous.

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            (a) This Warrant shall be binding on and inure to the benefit of the
parties hereto and their respective successors and assigns. Subject to the
preceding sentence, nothing in this Warrant shall be construed to give to any
Person other than the Company and the Holder any legal or equitable right,
remedy or cause of action under this Warrant. This Warrant may be amended in
writing signed by the Company and the Holder and their successors and assigns
and the Warrants issued pursuant to the Purchase Agreement, including this
Warrant, may be amended in writing signed by the Company and the Holders of no
less than a majority of the Warrant Shares issuable upon exercise of all such
then outstanding Warrants.

            (b) All questions concerning the construction, validity, enforcement
and interpretation of this Warrant shall be governed by and construed and
enforced in accordance with the internal laws of the State of Delaware, without
regard to the principles of conflicts of law thereof. Each party agrees that all
legal proceedings concerning the interpretations, enforcement and defense of
this Warrant and the transactions herein contemplated ("Proceedings") (whether
brought against a party hereto or its respective Affiliates, employees or
agents) may be commenced in the state and federal courts sitting in the State of
Delaware (the "Delaware Courts"). Each party hereto hereby irrevocably submits
to the non-exclusive jurisdiction of the Delaware Courts for the adjudication of
any dispute hereunder or in connection herewith or with any transaction
contemplated hereby or discussed herein, and hereby irrevocably waives, and
agrees not to assert in any Proceeding, any claim that it is not personally
subject to the jurisdiction of any Delaware Court, or that such Proceeding has
been commenced in an improper or inconvenient forum. Each party hereto hereby
irrevocably waives personal service of process and consents to process being
served in any such Proceeding by mailing a copy thereof via registered or
certified mail or overnight delivery (with evidence of delivery) to such party
at the address in effect for notices to it under this Warrant and agrees that
such service shall constitute good and sufficient service of process and notice
thereof. Nothing contained herein shall be deemed to limit in any way any right
to serve process in any manner permitted by law. Each party hereto hereby
irrevocably waives, to the fullest extent permitted by applicable law, any and
all right to trial by jury in any legal proceeding arising out of or relating to
this Warrant or the transactions contemplated hereby. If either party shall
commence a Proceeding to enforce any provisions of this Warrant, then the
prevailing party in such Proceeding shall be reimbursed by the other party for
its attorney's fees and other costs and expenses incurred with the
investigation, preparation and prosecution of such Proceeding.

            (c) The headings herein are for convenience only, do not constitute
a part of this Warrant and shall not be deemed to limit or affect any of the
provisions hereof.

            (d) In case any one or more of the provisions of this Warrant shall
be invalid or unenforceable in any respect, the validity and enforceability of
the remaining terms and provisions of this Warrant shall not in any way be
affected or impaired thereby and the parties will attempt in good faith to agree
upon a valid and enforceable provision which shall be a commercially reasonable
substitute therefor, and upon so agreeing, shall incorporate such substitute
provision in this Warrant.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK,
                             SIGNATURE PAGE FOLLOWS]

                                      -10-
<PAGE>

            IN WITNESS WHEREOF, the Company has caused this Warrant to be duly
executed by its authorized officer as of the date first indicated above.

                                            HEMISPHERX BIOPHARMA, INC.

                                            By: ________________________________
                                            Name:
                                            Title:

              SIGNATURE PAGE TO HEMISPHERX BIOPHARMA, INC. WARRANT

<PAGE>

                                 EXERCISE NOTICE

To Hemispherx Biopharma, Inc.:

      The undersigned hereby irrevocably elects to purchase _____________ shares
of common stock, $.001 par value ("Common Stock"), of Hemispherx Biopharma, Inc.
(the "Company"), pursuant to Warrant No. __________, originally issued August 5,
2004 (the "Warrant"), and, if such Holder is not utilizing the cashless exercise
provisions set forth in the Warrant, encloses herewith $________ in cash,
certified or official bank check or checks or other immediately available funds,
which sum represents the aggregate Exercise Price (as defined in the Warrant)
for the number of shares of Common Stock to which this Exercise Notice relates,
together with any applicable taxes payable by the undersigned pursuant to the
Warrant.

         By its delivery of this Exercise Notice, the undersigned represents and
warrants to the Company that (i) the aforesaid shares of Common Stock are being
acquired for the account of the undersigned for investment and not with a view
to, or for resale in connection with, the distribution thereof and that the
undersigned has no present intention of distributing or reselling such shares;
(ii) the undersigned is aware of the Company's business affairs and financial
condition and has acquired sufficient information about the Company to reach an
informed and knowledgeable decision regarding its investment in the Company;
(iii) the undersigned is experienced in making investments of this type and has
such knowledge and background in financial and business matters that the
undersigned is capable of evaluating the merits and risks of this investment and
protecting the undersigned's own interests; (iv) the undersigned is an
"accredited investor" as defined in Regulation D under the Securities Act of
1933, as amended (the "Securities Act"); and (v) the undersigned understands
that the shares of Common Stock issuable upon exercise of this Warrant have not
been registered under the Securities, by reason of a specific exemption from the
registration provisions of the Securities Act, which exemption depends upon,
among other things, the bona fide nature of the investment intent as expressed
herein, and, because such securities have not been registered under the
Securities Act, they must be held indefinitely unless subsequently registered
under the Securities Act or an exemption from such registration is available;
(v) the undersigned is aware that the aforesaid shares of Common Stock may not
be sold pursuant to Rule 144 adopted under the Securities Act unless certain
conditions are met and until the undersigned has held the shares for the number
of years prescribed by Rule 144; and (vi) the undersigned agrees not to make any
disposition of all or any part of the aforesaid shares of Common Stock unless
and until there is then in effect a registration statement under the Securities
Act covering such proposed disposition and such disposition is made in
accordance with said registration statement, or the undersigned has provided the
Company with an opinion of counsel satisfactory to the Company, stating that
such registration is not required.

      [By its delivery of this Exercise Notice, the undersigned represents and
warrants to the Company that in giving effect to the exercise evidenced hereby
the Holder will not beneficially own in excess of the number of shares of Common
Stock (determined in accordance with Section 13(d) of the Securities Exchange
Act of 1934) permitted to be owned under Section 11 of this Warrant to which
this notice relates.]

<PAGE>

(Exercise Notice Continued)

      The undersigned requests that certificates for the shares of Common Stock
issuable upon this exercise be issued in the name of the undersigned or in such
other name as is specified below:

                         ______________________________
                         (Please print name)

                         ______________________________
                         ______________________________
                         ______________________________
                         (Please print address)

                         ______________________________
                         (Please insert Social Security
                         or Tax Identification Number)

Dated: _______________, ____

                                         _______________________________________
                                         (Signature of Holder)

<PAGE>

                           Warrant Shares Exercise Log

--------------------------------------------------------------------------------
Date          Number of Warrant       Number of Warrant     Number of Warrant
              Shares Available to     Shares Exercised      Shares Remaining to
              be Exercised                                  be Exercised
--------------------------------------------------------------------------------

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

<PAGE>

                               FORM OF ASSIGNMENT

           [To be completed and signed only upon transfer of Warrant]

      FOR VALUE RECEIVED, the undersigned hereby sells, assigns and transfers
unto ________________________________ the right represented by the within
Warrant to purchase ____________ shares of Common Stock of Hemispherx Biopharma,
Inc. to which the within Warrant relates and appoints ________________ attorney
to transfer said right on the books of [___________] with full power of
substitution in the premises.

Dated: _______________, ____

                              __________________________________________________
                              (Signature must conform in all respects to name of
                              holder as specified on the face of the Warrant)

                              __________________________________________________
                              Address of Transferee

                              __________________________________________________

                              __________________________________________________

In the presence of:

__________________________Exhibit 10.3

                          REGISTRATION RIGHTS AGREEMENT

            This  Registration  Rights Agreement (this  "Agreement") is made and
entered into as of July 30, 2004,  by and among  Hemispherx  Biopharma,  Inc., a
Delaware corporation (the "Company"), and the investors signatory hereto (each a
"Purchaser" and collectively, the "Purchasers").

            This  Agreement  is  made  pursuant  to  the   Securities   Purchase
Agreement, dated as of the date hereof among the Company and the Purchasers (the
"Purchase Agreement").

            NOW,  THEREFORE,  IN CONSIDERATION of the mutual covenants contained
in this Agreement, and for other good and valuable consideration the receipt and
adequacy of which are hereby acknowledged,  the Company and the Purchasers agree
as follows:

      1.  Definitions.  Capitalized  terms used and not otherwise defined herein
that are defined in the Purchase  Agreement  shall have the meanings  given such
terms in the Purchase Agreement. As used in this Agreement,  the following terms
shall have the respective meanings set forth in this Section 1.

            "Effective  Date"  means  the date that the  Registration  Statement
filed pursuant to Section 2(a) is first declared effective by the Commission.

            "Effectiveness   Date"  means:  (a)  with  respect  to  the  initial
Registration  Statement  required to be filed to cover the resale by the Holders
of the Registrable  Securities,  the earlier of: (i) the 120th day following the
Closing  Date and (ii) the fifth  Trading  Day  following  the date on which the
Company is notified by the Commission  that the initial  Registration  Statement
will not be reviewed or is no longer subject to further review and comments, and
(b) with respect to any additional  Registration Statements that may be required
pursuant to Section 2(a) hereof, the earlier of: (i) the 120th day following the
date on which the Company  first knows,  or reasonably  should have known,  that
such additional  Registration  Statement is required under such Section and (ii)
the fifth Trading Day following the date on which the Company is notified by the
Commission that such additional  Registration  Statement will not be reviewed or
is no longer subject to further review and comments.  "Effectiveness Date" shall
also have the meaning specified in Section 2(b).

            "Effectiveness  Period"  shall have the meaning set forth in Section
2(a).

            "Exchange  Act"  means  the  Securities  Exchange  Act of  1934,  as
amended.

            "Filing  Date" means:  (a) with respect to the initial  Registration
Statement  required  to be filed to  cover  the  resale  by the  Holders  of the
Registrable  Securities,  the 45th day following the Closing Date,  and (b) with
respect to any additional  Registration Statements that may be required pursuant
to Section 2(a)  hereof,  the 45th day  following  the date on which the Company
first knows, or reasonably should have known, that such additional  Registration
Statement is required under such Section.

<PAGE>

            "Holder" or "Holders"  means the holder or holders,  as the case may
be, from time to time of Registrable Securities.

            "Indemnified  Party"  shall  have the  meaning  set forth in Section
5(c).

            "Indemnifying  Party"  shall have the  meaning  set forth in Section
5(c).

            "Losses" shall have the meaning set forth in Section 5(a).

            "Proceeding"  means  an  action,   claim,  suit,   investigation  or
proceeding   (including,   without  limitation,   an  investigation  or  partial
proceeding, such as a deposition), whether commenced or threatened.

            "Prospectus"  means  the  prospectus   included  in  a  Registration
Statement  (including,  without  limitation,  a  prospectus  that  includes  any
information  previously  omitted from a prospectus filed as part of an effective
registration  statement  in  reliance  upon  Rule  430A  promulgated  under  the
Securities Act), as amended or supplemented by any prospectus  supplement,  with
respect  to  the  terms  of  the  offering  of any  portion  of the  Registrable
Securities  covered by a Registration  Statement,  and all other  amendments and
supplements to the  Prospectus,  including  post-effective  amendments,  and all
material  incorporated by reference or deemed to be incorporated by reference in
such Prospectus.

            "Registrable  Securities"  means the Shares  issued  pursuant to the
Purchase  Agreement and the Warrant Shares,  together with any securities issued
or   issuable   upon  any  stock   split,   dividend   or  other   distribution,
recapitalization  or similar event,  or any  conversion  price  adjustment  with
respect thereto.

            "Registration Statement" means each of the following: (i) an initial
registration  statement  which  is  required  to  register  the  resale  of  the
Registrable Securities, and (ii) each additional registration statement, if any,
contemplated  by Section 2(d),  and  including,  in each case,  the  Prospectus,
amendments and  supplements to each such  registration  statement or Prospectus,
including pre- and  post-effective  amendments,  all exhibits  thereto,  and all
material  incorporated by reference or deemed to be incorporated by reference in
such registration statement.

            "Rule 144" means Rule 144 promulgated by the Commission  pursuant to
the  Securities  Act,  as such Rule may be  amended  from  time to time,  or any
similar  rule  or  regulation   hereafter   adopted  by  the  Commission  having
substantially the same effect as such Rule.

            "Rule 415" means Rule 415 promulgated by the Commission  pursuant to
the  Securities  Act,  as such Rule may be  amended  from  time to time,  or any
similar  rule  or  regulation   hereafter   adopted  by  the  Commission  having
substantially the same effect as such Rule.

            "Rule 424" means Rule 424 promulgated by the Commission  pursuant to
the  Securities  Act,  as such Rule may be  amended  from  time to time,  or any
similar  rule  or  regulation   hereafter   adopted  by  the  Commission  having
substantially the same effect as such Rule.

            "Securities Act" means the Securities Act of 1933, as amended.

                                      -2-
<PAGE>

            "Shares" shall have the meaning set forth in the Purchase Agreement.

            "Warrant  Shares"  shall have the meaning set forth in the  Purchase
Agreement.

      2. Registration.

            (a) On or prior to each Filing Date,  the Company  shall prepare and
file with the  Commission a  Registration  Statement  covering the resale of all
Registrable  Securities  not  already  covered  by  an  existing  and  effective
Registration Statement for an offering to be made on a continuous basis pursuant
to Rule 415.  The  Registration  Statement  shall be on Form S-3  (except if the
Company is not then eligible to register for resale the  Registrable  Securities
on Form S-3,  in which case such  registration  shall be on another  appropriate
form for such purpose) and shall contain (except if otherwise  required pursuant
to  written  comments  received  from  the  Commission  upon a  review  of  such
Registration  Statement) the "Plan of Distribution"  attached hereto as Annex A.
The Company  shall cause the  Registration  Statement  to be declared  effective
under the  Securities  Act as soon as possible but, in any event,  no later than
the Effectiveness  Date, and shall use its best efforts to keep the Registration
Statement  continuously  effective under the Securities Act until the date which
is two  years  after  the  date  that the  Registration  Statement  is  declared
effective by the Commission or such earlier date when all Registrable Securities
covered  by the  Registration  Statement  have been sold or may be sold  without
volume restrictions  pursuant to Rule 144(k) as determined by the counsel to the
Company  pursuant to a written  opinion  letter to such  effect,  addressed  and
acceptable  to the  Company's  transfer  agent  and the  affected  Holders  (the
"Effectiveness  Period").  It is agreed and  understood  that the Company shall,
from time to time, be obligated to file an additional  Registration Statement to
cover any Registrable Securities which are not registered for resale pursuant to
a pre-existing Registration Statement.

            (b) If for any  reason  the  Commission  does not  permit all of the
Registrable  Securities  to be  included  in the  Registration  Statement  filed
pursuant to Section  2(a),  then the Company  shall  prepare and file as soon as
possible  after the date on which the  Commission  shall  indicate  as being the
first date or time that such  filing  may be made,  but in any event by the 30th
day  following  such date,  an additional  Registration  Statement  covering the
resale of all  Registrable  Securities  not already  covered by an existing  and
effective  Registration  Statement  for an offering  to be made on a  continuous
basis  pursuant  to Rule 415,  on Form S-3  (except  if the  Company is not then
eligible to register for resale the Registrable Securities on Form S-3, in which
case such registration  shall be on another  appropriate form for such purpose).
Each such  Registration  Statement shall contain  (except if otherwise  required
pursuant to written comments  received from the Commission upon a review of such
Registration  Statement) the "Plan of Distribution"  attached hereto as Annex A.
The  Company  shall  cause  each  such  Registration  Statement  to be  declared
effective  under the  Securities  Act as soon as possible but, in any event,  no
later  than the 90th day  following  the filing of such  Registration  Statement
(each such 90th day, the "Effectiveness Date" for such Registration  Statement),
and shall use its best efforts to keep such Registration  Statement continuously
effective under the Securities Act during the entire Effectiveness Period.

            (c) If: (i) a Registration Statement is not filed on or prior to its
Filing Date (if the Company files a Registration Statement without affording the
Holders the opportunity to

                                      -3-
<PAGE>

review and comment on the same as required by Section 3(a)  hereof,  the Company
shall not be deemed to have  satisfied  this clause (i)), or (ii) a Registration
Statement  is not  declared  effective  by the  Commission  on or  prior  to its
required   Effectiveness   Date,  or  (iii)  after  its  Effective   Date,  such
Registration  Statement  ceases for any reason to be effective  and available to
the Holders as to all Registrable Securities to which it is required to cover at
any time prior to the expiration of its Effectiveness Period for an aggregate of
more than 20 consecutive  Trading Days or an aggregate of 40 Trading Days (which
need not be  consecutive),  (any such failure or breach being  referred to as an
"Event,"  and for  purposes  of clauses (i) or (ii) the date on which such Event
occurs, or for purposes of clause (iii) the date which such 20 consecutive or 40
Trading  Day-period  (as  applicable)  is exceeded,  being referred to as "Event
Date"),  then, in addition to any other rights available to the Holders:  (x) on
such  Event  Date the  Company  shall pay to each  Holder an amount in cash,  as
liquidated  damages and not as a penalty,  equal to 1% of the aggregate purchase
price paid by such Holder  pursuant to the Purchase  Agreement;  and (y) on each
monthly  anniversary  of each such Event Date thereof (if the  applicable  Event
shall not have been cured by such date) until the applicable Event is cured, the
Company  shall pay to each Holder an  additional  amount in cash,  as liquidated
damages and not as a penalty, equal to 1.0% of the aggregate purchase price paid
by such Holder pursuant to the Purchase  Agreement,  provided,  that all periods
shall be  tolled,  with  respect to a Holder,  by the number of Trading  Days in
excess of five (5) during  which such Holder  fails to provide the Company  with
information regarding such Holder which was requested by the Company in order to
effect the registration of such Holder's Registrable  Securities.  It shall be a
condition  precedent  to the  obligations  of the Company to pay any  liquidated
damages pursuant to this Section 2 with respect to the Registrable Securities of
any Holder  that such  Holder  shall  furnish to the  Company  such  information
regarding itself and the Registrable Securities held by it. If the Company fails
to pay any liquidated damages pursuant to this Section in full within seven days
after the date payable,  the Company will pay interest  thereon at a rate of 12%
per  annum  (or such  lesser  maximum  amount  that is  permitted  to be paid by
applicable  law) to the  Holder,  accruing  daily from the date such  liquidated
damages are due until such amounts,  plus all such interest thereon, are paid in
full. The liquidated  damages  pursuant to the terms hereof shall apply on a pro
rata basis for any portion of a month prior to the cure of an Event.

      3. Registration Procedures

            In connection with the Company's registration obligations hereunder,
the Company shall:

            (a) Not  less  than  four  Trading  Days  prior to the  filing  of a
Registration  Statement or any related Prospectus or any amendment or supplement
thereto,  the Company shall furnish to the Holders  copies of all such documents
proposed  to  be  filed  which  documents  (other  than  those  incorporated  by
reference) will be subject to the review of such Holders.  The Company shall not
file a  Registration  Statement  or any such  Prospectus  or any  amendments  or
supplements  thereto  to which the  Holders  of a  majority  of the  Registrable
Securities shall, in writing, reasonably object in good faith.

            (b) (i)  Prepare  and file  with  the  Commission  such  amendments,
including  post-effective  amendments,  to each  Registration  Statement and the
Prospectus  used in  connection  therewith  as may be  necessary  to  keep  such
Registration  Statement  continuously

                                      -4-
<PAGE>

effective as to the  applicable  Registrable  Securities  for its  Effectiveness
Period and prepare and file with the  Commission  such  additional  Registration
Statements in order to register for resale under the  Securities  Act all of the
Registrable  Securities;  (ii)  cause the  related  Prospectus  to be amended or
supplemented by any required  Prospectus  supplement,  and as so supplemented or
amended  to be  filed  pursuant  to Rule  424;  (iii)  respond  as  promptly  as
reasonably  possible,  and in any event within ten Trading Days, to any comments
received from the Commission with respect to each Registration  Statement or any
amendment  thereto and, as promptly as reasonably  possible  provide the Holders
true and  complete  copies  of all  correspondence  from  and to the  Commission
relating to such Registration  Statement that pertains to the Holders as Selling
Stockholders  but not any comments  that would result in the  disclosure  to the
Holders of material and non-public  information concerning the Company; and (iv)
comply in all material  respects with the  provisions of the  Securities Act and
the Exchange Act with respect to the Registration Statements and the disposition
of all Registrable Securities covered by each Registration Statement.

            (c) Notify the Holders as promptly as reasonably  possible  (and, in
the case of (i)(A) below, not less than three Trading Days prior to such filing)
and (if  requested by any such  Person)  confirm such notice in writing no later
than  one  Trading  Day  following  the  day  (i)(A)  when a  Prospectus  or any
Prospectus supplement or post-effective amendment to a Registration Statement is
proposed to be filed; (B) when the Commission notifies the Company whether there
will be a "review" of such  Registration  Statement and whenever the  Commission
comments in writing on such  Registration  Statement  (the Company shall provide
true and complete  copies thereof and all written  responses  thereto to each of
the Holders that pertain to the Holders as a Selling  Stockholder or to the Plan
of Distribution, but not information which the Company believes would constitute
material and non-public information);  and (C) with respect to each Registration
Statement or any post-effective  amendment,  when the same has become effective;
(ii) of any request by the Commission or any other Federal or state governmental
authority  for  amendments  or  supplements  to  a  Registration   Statement  or
Prospectus or for additional information that pertains to the Holders as Selling
Stockholders  or  the  Plan  of  Distribution;  (iii)  of  the  issuance  by the
Commission of any stop order  suspending  the  effectiveness  of a  Registration
Statement covering any or all of the Registrable Securities or the initiation of
any  Proceedings  for that  purpose;  (iv) of the  receipt by the Company of any
notification  with respect to the suspension of the  qualification  or exemption
from  qualification  of  any of  the  Registrable  Securities  for  sale  in any
jurisdiction,  or the  initiation  or  threatening  of any  Proceeding  for such
purpose;  and (v) of the  occurrence  of any event or passage of time that makes
the financial  statements  included in a Registration  Statement  ineligible for
inclusion  therein  or any  statement  made in such  Registration  Statement  or
Prospectus or any document  incorporated or deemed to be incorporated therein by
reference  untrue in any material respect or that requires any revisions to such
Registration  Statement,  Prospectus or other  documents so that, in the case of
such Registration  Statement or the Prospectus,  as the case may be, it will not
contain any untrue  statement  of a material  fact or omit to state any material
fact required to be stated therein or necessary to make the statements  therein,
in light of the circumstances under which they were made, not misleading.

            (d) Use its best  efforts to avoid the  issuance  of, or, if issued,
obtain  the  withdrawal  of (i) any  order  suspending  the  effectiveness  of a
Registration  Statement,  or  (ii)  any

                                      -5-
<PAGE>

suspension of the qualification (or exemption from  qualification) of any of the
Registrable Securities for sale in any jurisdiction, at the earliest practicable
moment.

            (e) Furnish to each Holder,  without charge,  at least one conformed
copy of each Registration  Statement and each amendment thereto and all exhibits
to the extent requested by such Person (including those previously  furnished or
incorporated by reference)  promptly after the filing of such documents with the
Commission;  provided,  that the Company shall have no obligation to provide any
document pursuant to this clause that is available on the EDGAR system.

            (f) Promptly deliver to each Holder,  without charge, as many copies
of each Prospectus or Prospectuses  (including each form of prospectus) and each
amendment or  supplement  thereto as such Persons may  reasonably  request.  The
Company  hereby  consents to the use of such  Prospectus  and each  amendment or
supplement  thereto  by each of the  selling  Holders  in  connection  with  the
offering and sale of the Registrable  Securities  covered by such Prospectus and
any amendment or supplement thereto.

            (g) Prior to any public offering of Registrable Securities,  use its
best  efforts to register or qualify or  cooperate  with the selling  Holders in
connection  with the  registration  or  qualification  (or  exemption  from such
registration or qualification) of such Registrable Securities for offer and sale
under the securities or Blue Sky laws of those  jurisdictions  within the United
States  set forth on  Schedule  3(g)  hereto to keep each such  registration  or
qualification (or exemption therefrom) effective during the Effectiveness Period
and to do any and all other acts or things  necessary or advisable to enable the
disposition in such  jurisdictions of the Registrable  Securities covered by the
Registration  Statements;  provided,  that the Company  shall not be required to
qualify  generally  to do business in any  jurisdiction  where it is not then so
qualified or subject the Company to any  material  tax in any such  jurisdiction
where it is not then so subject.

            (h) Cooperate with the Holders to facilitate the timely  preparation
and delivery of certificates representing Registrable Securities to be delivered
to a transferee  pursuant to the  Registration  Statements,  which  certificates
shall be  free,  to the  extent  permitted  by the  Purchase  Agreement,  of all
restrictive  legends,  and to enable such  Registrable  Securities to be in such
denominations and registered in such names as any such Holders may request.

            (i)  Upon  the  occurrence  of any  event  contemplated  by  Section
3(c)(v), as promptly as reasonably possible,  prepare a supplement or amendment,
including a post-effective amendment, to the affected Registration Statements or
a supplement to the related Prospectus or any document incorporated or deemed to
be incorporated  therein by reference,  and file any other required  document so
that, as thereafter delivered, no Registration Statement nor any Prospectus will
contain an untrue  statement of a material fact or omit to state a material fact
required to be stated  therein or necessary to make the statements  therein,  in
light of the circumstances under which they were made, not misleading.

            (j) The Company may require  each  selling  Holder to furnish to the
Company a  certified  statement  as to the  number  of  shares  of Common  Stock
beneficially owned by such Holder and any Affiliate thereof.

                                      -6-
<PAGE>

            (k) The Company has read and  understands  the exercise  limitations
contained  in  certain  of the  Warrants  and,  except  as may  be  required  by
applicable  law or  rules  or  regulations  of the  Commission,  will not take a
position in any Registration  Statement or other filing with the Commission that
a Holder whose  Warrant  contains such exercise  limitations  is the  beneficial
owner of more than the percentage of Common Stock  permitted to be  beneficially
owned by such Holder absent an affirmative  written  statement by such Holder to
such effect. It is understood and agreed that current law, rules and regulations
of the  Commission do not require the adoption of a position that a Holder whose
Warrant contains such exercise  limitations is the beneficial owner of more than
the percentage of Common Stock permitted to be beneficially owned by such Holder
pursuant to the exercise limitations contained in the Warrants.

      4. Registration  Expenses. All fees and expenses incident to the Company's
performance of its obligation  under this Agreement  (excluding any underwriting
discounts  and  selling  commissions  and all legal fees and  expenses  of legal
counsel  for any  Holder)  shall  be  borne by the  Company  whether  or not any
Registrable Securities are sold pursuant to a Registration  Statement.  The fees
and  expenses  referred to in the  foregoing  sentence  shall  include,  without
limitation, (i) all registration and filing fees (including, without limitation,
fees and  expenses  (A) with  respect  to filings  required  to be made with the
Trading Market on which the Common Stock is then listed for trading,  and (B) in
compliance with  applicable  state  securities or Blue Sky laws),  (ii) printing
expenses (including,  without limitation,  expenses of printing certificates for
Registrable   Securities  and  of  printing  prospectuses  if  the  printing  of
prospectuses  is  reasonably  requested  by the  holders  of a  majority  of the
Registrable Securities included in the Registration Statement), (iii) messenger,
telephone and delivery expenses,  (iv) fees and disbursements of counsel for the
Company, (v) Securities Act liability insurance,  if the Company so desires such
insurance,  and (vi) fees and  expenses  of all other  Persons  retained  by the
Company in connection with the consummation of the transactions  contemplated by
this  Agreement.  In addition,  the Company shall be responsible  for all of its
internal   expenses   incurred  in  connection  with  the  consummation  of  the
transactions contemplated by this Agreement (including,  without limitation, all
salaries  and  expenses  of its  officers  and  employees  performing  legal  or
accounting  duties),  the expense of any annual  audit and the fees and expenses
incurred in  connection  with the listing of the  Registrable  Securities on any
securities exchange as required hereunder.

      5. Indemnification.

            (a)   Indemnification   by   the   Company.   The   Company   shall,
notwithstanding  any termination of this Agreement,  indemnify and hold harmless
each Holder, the officers,  directors,  agents,  investment advisors,  partners,
members,  shareholders  and employees of each of them,  each Person who controls
any such  Holder  (within  the  meaning of Section 15 of the  Securities  Act or
Section  20 of the  Exchange  Act)  and  the  officers,  directors,  agents  and
employees of each such  controlling  Person,  to the fullest extent permitted by
applicable  law,  from  and  against  any  and  all  losses,  claims,   damages,
liabilities,   costs  (including,   without  limitation,   reasonable  costs  of
preparation  and  reasonable   attorneys'  fees)  and  expenses   (collectively,
"Losses"),  as  incurred,  arising  out of or  relating to any untrue or alleged
untrue statement of a material fact contained in any Registration Statement, any
Prospectus or any form of  prospectus or in any amendment or supplement  thereto
(it being  understood  that the  Holder

                                      -7-
<PAGE>

has approved Annex A hereto for this purpose) or in any preliminary  prospectus,
or arising out of or relating to any omission or alleged  omission of a material
fact required to be stated therein or necessary to make the  statements  therein
(in the case of any Prospectus or form of prospectus or supplement  thereto,  in
light of the circumstances under which they were made) not misleading, except to
the extent, but only to the extent, that (1) such untrue statements or omissions
are based solely upon information  regarding such Holder furnished in writing to
the Company by such Holder expressly for use therein, or to the extent that such
information  relates  to  such  Holder  or  such  Holder's  proposed  method  of
distribution of Registrable  Securities and was reviewed and expressly  approved
in writing by such Holder expressly for use in the Registration Statement,  such
Prospectus or such form of Prospectus or in any amendment or supplement  thereto
(it being  understood  that each  Holder  has  approved  Annex A hereto for this
purpose) or (2) in the case of an occurrence  of an event of the type  specified
in Section  3(c)(ii)-(v),  the use by such Holder of an  outdated  or  defective
Prospectus  after the  Company  has  notified  such  Holder in writing  that the
Prospectus  is outdated or defective  and prior to the receipt by such Holder of
an Advice  or an  amended  or  supplemented  Prospectus,  but only if and to the
extent that  following the receipt of the Advice or the amended or  supplemented
Prospectus the misstatement or omission giving rise to such Loss would have been
corrected.  The Company  shall notify the Holders  promptly of the  institution,
threat  or  assertion  of any  Proceeding  of  which  the  Company  is  aware in
connection with the transactions contemplated by this Agreement.

            (b) Indemnification by Holders.  Each Holder shall,  notwithstanding
any termination of this Agreement, severally and not jointly, indemnify and hold
harmless the Company, its directors, officers, agents and employees, each Person
who controls the Company (within the meaning of Section 15 of the Securities Act
and Section 20 of the Exchange  Act),  and the  directors,  officers,  agents or
employees  of such  controlling  Persons,  to the fullest  extent  permitted  by
applicable law, from and against all Losses, as incurred,  arising solely out of
or based solely upon:  (x) such Holder's  failure to comply with the  prospectus
delivery  requirements  of the Securities  Act or (y) any untrue  statement of a
material fact contained in any Registration  Statement,  any Prospectus,  or any
form of prospectus, or in any amendment or supplement thereto, or arising solely
out of or based  solely  upon any  omission  of a material  fact  required to be
stated therein or necessary to make the statements therein not misleading to the
extent, but only to the extent that, (1) such untrue statements or omissions are
based solely upon information  regarding such Holder furnished in writing to the
Company by such Holder  expressly  for use  therein,  or to the extent that such
information  relates  to  such  Holder  or  such  Holder's  proposed  method  of
distribution of Registrable  Securities and was reviewed and expressly  approved
in writing by such Holder  expressly for use in the  Registration  Statement (it
being understood that each Holder has approved Annex A hereto for this purpose),
such  Prospectus  or such form of  Prospectus  or in any amendment or supplement
thereto or (2) in the case of an occurrence of an event of the type specified in
Section  3(c)(ii)-(v),  the use by  such  Holder  of an  outdated  or  defective
Prospectus  after the  Company  has  notified  such  Holder in writing  that the
Prospectus  is outdated or defective  and prior to the receipt by such Holder of
an Advice  or an  amended  or  supplemented  Prospectus,  but only if and to the
extent that  following the receipt of the Advice or the amended or  supplemented
Prospectus the misstatement or omission giving rise to such Loss would have been
corrected.  In no event shall the liability of any selling  Holder  hereunder be
greater in amount than the dollar  amount of the net  proceeds  received by such
Holder  upon  the  sale  of the  Registrable  Securities  giving  rise  to  such
indemnification obligation.

                                      -8-
<PAGE>

            (c) Conduct of Indemnification  Proceedings. If any Proceeding shall
be brought or asserted  against any Person  entitled to indemnity  hereunder (an
"Indemnified  Party"),  such Indemnified  Party shall promptly notify the Person
from whom  indemnity is sought (the  "Indemnifying  Party") in writing,  and the
Indemnifying Party shall assume the defense thereof, including the employment of
counsel reasonably  satisfactory to the Indemnified Party and the payment of all
fees and expenses  incurred in connection with defense thereof;  provided,  that
the failure of any  Indemnified  Party to give such notice shall not relieve the
Indemnifying Party of its obligations or liabilities pursuant to this Agreement,
except (and only) to the extent that it shall be finally  determined  by a court
of  competent  jurisdiction  (which  determination  is not  subject to appeal or
further  review)  that  such  failure  shall  have  proximately  and  materially
adversely prejudiced the Indemnifying Party.

            An Indemnified Party shall have the right to employ separate counsel
in any such Proceeding and to participate in the defense  thereof,  but the fees
and expenses of such counsel shall be at the expense of such  Indemnified  Party
or Parties unless:  (1) the Indemnifying Party has agreed in writing to pay such
fees and  expenses;  (2) the  Indemnifying  Party shall have failed  promptly to
assume  the  defense  of  such  Proceeding  and  to  employ  counsel  reasonably
satisfactory to such Indemnified Party in any such Proceeding;  or (3) the named
parties to any such Proceeding  (including any impleaded  parties)  include both
such Indemnified  Party and the Indemnifying  Party, and such Indemnified  Party
shall have been  advised by counsel  that a conflict  of  interest  is likely to
exist if the same  counsel  were to  represent  such  Indemnified  Party and the
Indemnifying  Party (in which  case,  if such  Indemnified  Party  notifies  the
Indemnifying  Party in writing that it elects to employ separate  counsel at the
expense of the Indemnifying  Party,  the  Indemnifying  Party shall not have the
right to assume the defense  thereof and such counsel shall be at the expense of
the Indemnifying  Party),  provided,  that the  Indemnifying  Party shall not be
liable for the fees and expenses of more than one separate  firm of attorneys at
any time for all Indemnified Parties. The Indemnifying Party shall not be liable
for any settlement of any such Proceeding  effected without its written consent,
which consent shall not be unreasonably  withheld.  No Indemnifying Party shall,
without  the  prior  written  consent  of  the  Indemnified  Party,  effect  any
settlement of any pending  Proceeding in respect of which any Indemnified  Party
is a party,  unless such settlement  includes an  unconditional  release of such
Indemnified  Party from all  liability on claims that are the subject  matter of
such Proceeding.

            All fees and expenses of the Indemnified Party (including reasonable
fees and expenses to the extent  incurred in connection  with  investigating  or
preparing  to defend  such  Proceeding  in a manner not  inconsistent  with this
Section) shall be paid to the Indemnified Party, as incurred, within ten Trading
Days of written notice thereof to the Indemnifying  Party (regardless of whether
it is  ultimately  determined  that an  Indemnified  Party  is not  entitled  to
indemnification  hereunder;  provided,  that the Indemnifying  Party may require
such  Indemnified  Party to undertake to reimburse all such fees and expenses to
the extent it is finally  judicially  determined that such Indemnified  Party is
not entitled to indemnification hereunder).

            (d) Contribution.  If a claim for indemnification under Section 5(a)
or 5(b) is unavailable  to an  Indemnified  Party (by reason of public policy or
otherwise),   then  each  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,  in  such  proportion  as is
appropriate  to  reflect  the  relative  fault  of the  Indemnifying  Party  and
Indemnified  Party in

                                      -9-
<PAGE>

connection  with the  actions,  statements  or omissions  that  resulted in such
Losses as well as any other  relevant  equitable  considerations.  The  relative
fault of such  Indemnifying  Party and Indemnified  Party shall be determined by
reference to, among other things, whether any action in question,  including any
untrue or alleged  untrue  statement  of a material  fact or omission or alleged
omission  of a  material  fact,  has  been  taken  or made  by,  or  relates  to
information  supplied by, such Indemnifying  Party or Indemnified Party, and the
parties'  relative intent,  knowledge,  access to information and opportunity to
correct or prevent  such  action,  statement  or  omission.  The amount  paid or
payable by a party as a result of any Losses shall be deemed to include, subject
to the limitations set forth in Section 5(c), any reasonable attorneys' or other
reasonable  fees or  expenses  incurred  by such  party in  connection  with any
Proceeding to the extent such party would have been indemnified for such fees or
expenses if the  indemnification  provided for in this Section was  available to
such party in accordance with its terms.

            The parties  hereto agree that it would not be just and equitable if
contribution  pursuant  to  this  Section  5(d)  were  determined  by  pro  rata
allocation or by any other method of allocation  that does not take into account
the equitable considerations referred to in the immediately preceding paragraph.
Notwithstanding the provisions of this Section 5(d), no Holder shall be required
to contribute, in the aggregate, any amount in excess of the amount by which the
proceeds  actually  received  by such  Holder  from the sale of the  Registrable
Securities subject to the Proceeding exceeds the amount of any damages that such
Holder has  otherwise  been  required to pay by reason of such untrue or alleged
untrue statement or omission or alleged omission.

            The indemnity and contribution  agreements contained in this Section
are in addition to any liability that the  Indemnifying  Parties may have to the
Indemnified Parties.

      6. Miscellaneous

            (a)  Remedies.  In the  event of a  breach  by the  Company  or by a
Holder,  of any of their  obligations  under this Agreement,  each Holder or the
Company,  as the case may be, in  addition to being  entitled  to  exercise  all
rights granted by law and under this Agreement,  including  recovery of damages,
will be entitled to specific performance of its rights under this Agreement. The
Company and each Holder agree that monetary  damages would not provide  adequate
compensation  for any losses  incurred by reason of a breach by it of any of the
provisions of this Agreement and hereby further agrees that, in the event of any
action for specific  performance  in respect of such breach,  it shall waive the
defense that a remedy at law would be adequate.

            (b) Compliance. Each Holder covenants and agrees that it will comply
with the prospectus delivery requirements of the Securities Act as applicable to
it  in  connection  with  sales  of  Registrable   Securities  pursuant  to  the
Registration Statement.

            (c) Discontinued Disposition.  Each Holder agrees by its acquisition
of such  Registrable  Securities that, upon receipt of a notice from the Company
of the  occurrence  of any event of the kind  described  in Section  3(c),  such
Holder will forthwith  discontinue  disposition of such  Registrable  Securities
under the  Registration  Statement until such Holder's  receipt of the copies of
the supplemented Prospectus and/or amended Registration Statement or until it is

                                      -10-
<PAGE>

advised in writing (the  "Advice") by the Company that the use of the applicable
Prospectus  may be resumed,  and, in either  case,  has  received  copies of any
additional  or  supplemental  filings  that are  incorporated  or  deemed  to be
incorporated  by reference in such  Prospectus or  Registration  Statement.  The
Company may provide  appropriate  stop orders to enforce the  provisions of this
paragraph.

            (d) Piggy-Back  Registrations.  If at any time after the Filing Date
and  prior  to  the  expiration  of the  Effectiveness  Period  there  is not an
effective  Registration Statement covering all of the Registrable Securities and
the  Company  shall  determine  to  prepare  and file,  or has  filed,  with the
Commission a registration  statement relating to an offering for its own account
or the  account  of  others  under  the  Securities  Act  of  any of its  equity
securities,  other than on Form S-4 or Form S-8 (each as  promulgated  under the
Securities Act) or their then  equivalents  relating to equity  securities to be
issued solely in connection  with any  acquisition  of any entity or business or
equity  securities  issuable in connection  with stock option or other  employee
benefit plans, then the Company shall send to each Holder written notice of such
determination and, if within fifteen days after receipt of such notice, any such
Holder  shall  so  request  in  writing,  the  Company  shall  include  in  such
registration  statement  all or any  part of such  Registrable  Securities  such
holder  requests to be  registered,  subject to customary  underwriter  cutbacks
applicable to all holders of registration rights.

            (e)  Amendments  and Waivers.  No provision of this Agreement may be
waived or amended except in a written  instrument  signed by the Company and the
Holder  or  Holders  (as  applicable)  of no less  than a  majority  of the then
outstanding Registrable Securities. No waiver of any default with respect to any
provision,  condition or requirement  of this Agreement  shall be deemed to be a
continuing  waiver  in the  future or a waiver of any  subsequent  default  or a
waiver of any other provision,  condition or requirement  hereof,  nor shall any
delay or omission of either party to exercise any right  hereunder in any manner
impair the exercise of any such right.

            (f)  Notices.  Any  and  all  notices  or  other  communications  or
deliveries  required or permitted to be provided  hereunder  shall be in writing
and  shall be deemed  given and  effective  on the  earliest  of (i) the date of
transmission,  if such notice or communication is delivered via facsimile at the
facsimile number specified in this Section prior to 5:00 p.m. (New York time) on
a Business  Day, (ii) the Business Day after the date of  transmission,  if such
notice or  communication  is delivered via facsimile at the facsimile  telephone
number  specified in this Agreement  later than 5:00 p.m. (New York time) on any
date and  earlier  than  11:59  p.m.  (New York  time) on such  date,  (iii) the
Business Day  following the date of mailing,  if sent by  nationally  recognized
overnight courier service, or (iv) upon actual receipt by the party to whom such
notice is required to be given. The address for such notices and  communications
shall be as follows:

                                      -11-
<PAGE>

            If to the Company:

                    Hemispherx Biopharma, Inc.
                    1617 JFK Boulevard
                    Suite 660
                    Philadelphia, PA 19103
                    Telephone: (215) 998-8000
                    Facsimile: (215) 998-1739
                    Attention: Chief Executive Officer

            With a copy to:

                    Ransom W. Etheridge, Esq.
                    2610 Potters Road
                    Suite 200
                    Virginia Beach, VA  23452
                    Telephone: (757-486-0599
                    Facsimile: (757) 486-0792

      If to a Purchaser:     To the address set forth under such Purchaser's
                             name on the signature pages hereto.

      If to any other Person who is then the registered Holder:

                             To the address of such Holder as it appears
                             in the stock transfer books of the Company

or such other  address as may be designated  in writing  hereafter,  in the same
manner, by such Person.

            (g)  Successors  and  Assigns.  This  Agreement  shall  inure to the
benefit of and be binding upon the successors  and permitted  assigns of each of
the parties and shall inure to the benefit of each  Holder.  The Company may not
assign its rights or obligations  hereunder without the prior written consent of
each Holder.  Each Holder may assign their  respective  rights  hereunder in the
manner and to the Persons as permitted under the Purchase Agreement.

            (h) Execution and  Counterparts.  This  Agreement may be executed in
any number of counterparts, each of which when so executed shall be deemed to be
an original and, all of which taken together  shall  constitute one and the same
Agreement.   In  the  event  that  any   signature  is  delivered  by  facsimile
transmission,  such  signature  shall create a valid  binding  obligation of the
party  executing  (or on whose behalf such  signature is executed) the same with
the same  force and  effect as if such  facsimile  signature  were the  original
thereof.

            (i)  Governing  Law.  All  questions  concerning  the  construction,
validity,  enforcement and interpretation of this Agreement shall be governed by
and construed and

                                      -12-
<PAGE>

enforced in accordance with the internal laws of the State of Delaware,  without
regard to the principles of conflicts of law thereof. Each party agrees that all
Proceedings  concerning  the  interpretations,  enforcement  and  defense of the
transactions  contemplated  by this Agreement  (whether  brought against a party
hereto or its  respective  Affiliates,  employees or agents) may be commenced in
the state and federal  courts  sitting in the State of Delaware  (the  "Delaware
Courts").  Each party hereto  hereby  irrevocably  submits to the  non-exclusive
jurisdiction  of the  Delaware  Courts  for  the  adjudication  of  any  dispute
hereunder or in connection herewith or with any transaction  contemplated hereby
or discussed herein, and hereby irrevocably  waives, and agrees not to assert in
any Proceeding,  any claim that it is not personally subject to the jurisdiction
of any Delaware Court, or that such Proceeding has been commenced in an improper
or  inconvenient  forum.  Each party hereto hereby  irrevocably  waives personal
service of process and consents to process  being served in any such  Proceeding
by mailing a copy thereof via registered or certified mail or overnight delivery
(with  evidence of  delivery) to such party at the address in effect for notices
to it under this  Agreement and agrees that such service shall  constitute  good
and sufficient  service of process and notice thereof.  Nothing contained herein
shall be  deemed to limit in any way any right to serve  process  in any  manner
permitted by law. Each party hereto hereby  irrevocably  waives,  to the fullest
extent  permitted by  applicable  law, any and all right to trial by jury in any
Proceeding  arising  out of or relating to this  Agreement  or the  transactions
contemplated  hereby. If either party shall commence a Proceeding to enforce any
provisions of this Agreement, then the prevailing party in such Proceeding shall
be  reimbursed  by the other party for its  attorney's  fees and other costs and
expenses  incurred with the  investigation,  preparation and prosecution of such
Proceeding.

            (j) Cumulative Remedies. The remedies provided herein are cumulative
and not exclusive of any remedies provided by law.

            (k) Severability. If any term, provision, covenant or restriction of
this  Agreement  is held by a court of  competent  jurisdiction  to be  invalid,
illegal,  void  or  unenforceable,  the  remainder  of  the  terms,  provisions,
covenants  and  restrictions  set forth  herein  shall  remain in full force and
effect and shall in no way be affected, impaired or invalidated, and the parties
hereto  shall use their  reasonable  efforts to find and  employ an  alternative
means to achieve the same or substantially  the same result as that contemplated
by such term,  provision,  covenant or restriction.  It is hereby stipulated and
declared to be the  intention of the parties  that they would have  executed the
remaining terms, provisions, covenants and restrictions without including any of
such that may be hereafter declared invalid, illegal, void or unenforceable.

            (l) Headings.  The headings in this Agreement are for convenience of
reference only and shall not limit or otherwise affect the meaning hereof.

            (m) Independent  Nature of Purchasers'  Obligations and Rights.  The
obligations  of each  Purchaser  hereunder  is  several  and not joint  with the
obligations  of any  other  Purchaser  hereunder,  and  no  Purchaser  shall  be
responsible  in any way for the  performance  of the  obligations  of any  other
Purchaser  hereunder.  The  decision of each  Purchaser  to purchase  Securities
pursuant to the Transaction  Documents has been made  independently of any other
Purchaser.  Nothing  contained  herein or in any  other  agreement  or  document
delivered at any closing,  and no action taken by any Purchaser  pursuant hereto
or thereto,  shall be deemed to constitute the  Purchasers as a partnership,  an
association,  a  joint  venture  or any  other  kind  of

                                      -13-
<PAGE>

entity,  or create a presumption  that the  Purchasers  are in any way acting in
concert with respect to such  obligations or the  transactions  contemplated  by
this Agreement. Each Purchaser acknowledges that no other Purchaser has acted as
agent for such Purchaser in connection with making its investment  hereunder and
that no Purchaser will be acting as agent of such  Purchaser in connection  with
monitoring  its  investment in the  Securities or enforcing its rights under the
Transaction  Documents.  Each Purchaser shall be entitled to protect and enforce
its  rights,  including  without  limitation  the  rights  arising  out of  this
Agreement, and it shall not be necessary for any other Purchaser to be joined as
an additional party in any proceeding for such purpose.

                   [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK
                           SIGNATURE PAGES TO FOLLOW]

                                      -14-
<PAGE>

      IN WITNESS  WHEREOF,  the parties have executed this  Registration  Rights
Agreement as of the date first written above.

                                            HEMISPHERX BIOPHARMA, INC.

                                            By:_________________________________
                                            Name:
                                            Title:

                   [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK
                     SIGNATURE PAGES OF PURCHASER TO FOLLOW]

                                      -15-
<PAGE>

      IN WITNESS  WHEREOF,  the parties have executed this  Registration  Rights
Agreement as of the date first written above.

                      [____________________________]

                      By:_____________________________________
                          Name:
                          Title:

                      Address for Notice:

                      [___________________]
                      [___________________]
                      [___________________]
                      Facsimile No.:
                      Attn.:

                      With a copy to:

                      [___________________]
                      [___________________]
                      [___________________]
                      Facsimile No.:
                      Attn:

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