Document:

Securities
Purchase Agreement

 

This
Securities Purchase Agreement (this “Agreement”),
dated as of September 28, 2018, is entered into by and between Hemispherx Biopharma, Inc.,
a Delaware corporation (“Company”), and Iliad Research and Trading,
L.P., a Utah limited partnership, its successors and/or assigns (“Investor”).

 

A.
Company and Investor are executing and delivering this Agreement in reliance upon the exemption from securities registration afforded
by the Securities Act of 1933, as amended (the “1933 Act”), and the rules and regulations promulgated thereunder
by the United States Securities and Exchange Commission (the “SEC”).

 

B.
Investor desires to purchase and Company desires to issue and sell, upon the terms and conditions set forth in this Agreement
(i) a Secured Convertible Promissory Note, in the form attached hereto as Exhibit A, in the original principal amount of
$3,170,000.00 (the “Note”), convertible into shares of common stock, $0.001 par value per share, of Company
(the “Common Stock”), upon the terms and subject to the limitations and conditions set forth in such Note,
and (ii) 500,000 shares of Common Stock (the “Origination Shares”).

 

C.
This Agreement, the Note, the Security Agreement (as defined below), and all other certificates, documents, agreements, resolutions
and instruments delivered to any party under or in connection with this Agreement, as the same may be amended from time to time,
are collectively referred to herein as the “Transaction Documents”.

 

D.
For purposes of this Agreement: “Conversion Shares” means all shares of Common Stock issuable upon conversion
of all or any portion of the Note; and “Securities” means the Note, the Origination Shares and the Conversion
Shares.

 

NOW,
THEREFORE, in consideration of the above recitals and other good and valuable consideration, the receipt and sufficiency of
which are hereby acknowledged, Company and Investor hereby agree as follows:

 

1.
Purchase and Sale of Securities.

 

1.1.
Purchase of Securities. Company shall issue and sell to Investor and Investor shall purchase from Company the Note. In
consideration thereof, Investor shall pay the Purchase Price (as defined below) to Company. Company agrees to deliver the Origination
Shares to Investor within five (5) Trading Days of the Closing Date.

 

1.2.
Form of Payment. On the Closing Date (as defined below), Investor shall pay the Purchase Price to Company via wire transfer
of immediately available funds against delivery of the Note and the Origination Shares.

 

1.3.
Closing Date. Subject to the satisfaction (or written waiver) of the conditions set forth in Section 5 and Section 6 below,
the date of the issuance and sale of the Note pursuant to this Agreement (the “Closing Date”) shall be September
28, 2018, or another mutually agreed upon date. The closing of the transactions contemplated by this Agreement (the “Closing”)
shall occur on the Closing Date by means of the exchange by email of signed .pdf documents, but shall be deemed for all purposes
to have occurred at the offices of Hansen Black Anderson Ashcraft PLLC in Lehi, Utah.

 

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1.4.
Collateral for the Note. The Note shall be secured by the collateral set forth in that certain Security Agreement attached
hereto as Exhibit B listing certain of Company’s assets as security for Company’s obligations under the Transaction
Documents (the “Security Agreement”). The parties acknowledge and agree that the collateral covered by the
Security Agreement is currently encumbered by Company’s landlord and that such security interest of the landlord shall be
deemed a “Permitted Lien” under the Security Agreement. Investor agrees that if Company is able to get its landlord
to subordinate its security interest to Investor resulting in Investor having a first priority lien in the collateral within thirty
(30) days of the Closing Date, then Investor will return the Origination Shares to Company.

 

1.5.
Original Issue Discount; Transaction Expense Amount. The Note carries an original issue discount of $150,000.00 (the “OID”).
In addition, Company agrees to pay $20,000.00 to Investor to cover Investor’s legal fees, accounting costs, due diligence,
monitoring and other transaction costs incurred in connection with the purchase and sale of the Securities (the “Transaction
Expense Amount”), all of which amount is included in the initial principal balance of the Note. The “Purchase
Price”, therefore, shall be $3,000,000.00, computed as follows: $3,170,000.00 initial principal balance, less the OID,
less the Transaction Expense Amount.

 

2.
Investor’s Representations and Warranties. Investor represents and warrants to Company that as of the Closing Date:
(i) Investor is a limited partnership duly formed, validly existing and in good standing under the laws of its state of formation
and has the requisite limited partnership power and authority to enter into and consummate the transactions contemplated by the
Transaction Documents; (ii) each of the Transaction Documents to which it is a party and the transactions contemplated hereby
and thereby have been duly and validly authorized by the Investor; (iii) each of the Transaction Documents to which it is a party
constitutes a valid and binding agreement of Investor enforceable in accordance with its terms; (iv) Investor is an “accredited
investor” as that term is defined in Rule 501(a) )(1), (a)(2), (a)(3), (a)(7) or (a)(8) under the Securities Act of the
1933 Act; (v) Investor is acquiring the Securities as principal for its own account and not with a view to or for distributing
or reselling the Securities or any part thereof in violation of the 1933 Act or any applicable state securities law and has no
present intention of distributing any of the Securities in violation of the 1933 Act or any applicable state securities law; (vi)
Investor has such knowledge, sophistication and experience in business and financial matters so as to be capable of evaluating
the merits and risks of the prospective investment in the Securities, and has so evaluated the merits and risks of such investment;
(vii) Investor acknowledges that it has had the opportunity to review the Transaction Documents and the Company’s filings
with the SEC and has been afforded, (a) the opportunity to ask such questions as it has deemed necessary of, and to receive answers
from, representatives of the Company concerning the transactions contemplated by the Transaction Documents and the merits and
risks of investing in the Securities; (B) access to information about the Company and its financial condition, results of operations,
business, properties, management and prospects sufficient to enable it to evaluate its investment and (C) the opportunity to obtain
such additional information that the Company possesses or can acquire without unreasonable effort or expense that is necessary
to make an informed investment decision with respect to the investment; and (viii) Investor is not purchasing the Securities as
a result of any advertisement, article, notice or other communication regarding the Securities published in any newspaper, magazine
or similar media or broadcast over television or radio or presented at any seminar or, to Investor’s knowledge, any other
general solicitation or general advertisement.

 

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3.
Company’s Representations and Warranties. Company represents and warrants to Investor that as of the Closing Date:
(i) Company is a corporation duly organized, validly existing and in good standing under the laws of its state of incorporation
and has the requisite corporate power to own its properties and to carry on its business as now being conducted; (ii) Company
is duly qualified as a foreign corporation to do business and is in good standing in each jurisdiction where the nature of the
business conducted or property owned by it makes such qualification necessary; (iii) Company has registered its Common Stock under
Section 12(b) of the Securities Exchange Act of 1934, as amended (the “1934 Act”), and is obligated to file
reports pursuant to Section 13 or Section 15(d) of the 1934 Act; (iv) each of the Transaction Documents and the transactions contemplated
hereby and thereby, have been duly and validly authorized by Company and all necessary actions have been taken; (v) this Agreement,
the Note, the Security Agreement and the other Transaction Documents have been duly executed and delivered by Company and constitute
the valid and binding obligations of Company enforceable in accordance with their terms; (vi) the execution and delivery of the
Transaction Documents by Company, the issuance of Securities in accordance with the terms hereof, and the consummation by Company
of the other transactions contemplated by the Transaction Documents do not and will not conflict with or result in a breach by
Company of any of the terms or provisions of, or constitute a default under (a) Company’s formation documents or bylaws,
each as currently in effect, (b) any indenture, mortgage, deed of trust, or other material agreement or instrument to which Company
is a party or by which it or any of its properties or assets are bound, including, without limitation, any listing agreement for
the Common Stock, or (c) any existing applicable law, rule, or regulation or any applicable decree, judgment, or order of any
court, United States federal, state or foreign regulatory body, administrative agency, or other governmental body having jurisdiction
over Company or any of Company’s properties or assets; (vii) no further authorization, approval or consent of any court,
governmental body, regulatory agency, self-regulatory organization, or stock exchange or market or the stockholders or any lender
of Company is required to be obtained by Company for the issuance of the Securities to Investor in accordance with the Transaction
Documents or the entering into of the Transaction Documents; (viii) since March 30, 2018, none of Company’s filings with
the SEC contained, at the time they were filed, any untrue statement of a material fact or omitted to state any material fact
required to be stated therein or necessary to make the statements made therein, in light of the circumstances under which they
were made, not misleading; (ix) since September 1, 2016, Company has filed all reports, schedules, forms, statements and other
documents required to be filed by Company with the SEC under the 1934 Act on a timely basis or has received a valid extension
of such time of filing and has filed any such report, schedule, form, statement or other document prior to the expiration of any
such extension; (x) except as described in the Company’s filings with the SEC, there is no action, suit, proceeding, inquiry
or investigation before or by any court, public board or body pending or, to the knowledge of Company, threatened against or affecting
Company before or by any governmental authority or non-governmental department, commission, board, bureau, agency or instrumentality
or any other person, wherein an unfavorable decision, ruling or finding would have a material adverse effect on Company or which
would adversely affect the validity or enforceability of, or the authority or ability of Company to perform its obligations under,
any of the Transaction Documents; (xi) Company has not consummated any financing transaction that has not been disclosed in a
periodic filing or current report with the SEC under the 1934 Act; (xii) Company is not, nor has it been at any time in the previous
twelve (12) months, a “Shell Company,” as such type of “issuer” is described in Rule 144(i)(1) under the
1933 Act; (xiii) with respect to any commissions, placement agent or finder’s fees or similar payments that will or would
become due and owing by Company to any person or entity as a result of this Agreement or the transactions contemplated hereby
(“Broker Fees”), any such Broker Fees will be made in full compliance with all applicable laws and regulations
and only to a person or entity that is a registered investment adviser or registered broker-dealer; (xiv) Investor shall have
no obligation with respect to any Broker Fees or with respect to any claims made by or on behalf of other persons for fees of
a type contemplated in this subsection that may be due in connection with the transactions contemplated hereby and Company shall
indemnify and hold harmless each of Investor, Investor’s employees, officers, directors, stockholders, members, managers,
agents, and partners, and their respective affiliates, from and against all claims, losses, damages, costs (including the costs
of preparation and attorneys’ fees) and expenses suffered in respect of any such claimed Broker Fees; (xv) when issued upon
conversion of the Note in accordance with the terms of the Note or in accordance with the terms of this Agreement, as applicable,
the Origination Shares and the Conversion Shares will be duly authorized, validly issued, fully paid for and non-assessable, free
and clear of all liens, claims, charges and encumbrances; (xvi) neither Investor nor any of its officers, directors, stockholders,
members, managers, employees, agents or representatives has made any representations or warranties to Company or any of its officers,
directors, employees, agents or representatives except as expressly set forth in the Transaction Documents and, in making its
decision to enter into the transactions contemplated by the Transaction Documents, Company is not relying on any representation,
warranty, covenant or promise of Investor or its officers, directors, members, managers, employees, agents or representatives
other than as set forth in the Transaction Documents; (xvii) Company acknowledges that the State of Utah has a reasonable relationship
and sufficient contacts to the transactions contemplated by the Transaction Documents and any dispute that may arise related thereto
such that the laws and venue of the State of Utah, as set forth more specifically in Section 8.2 below, shall be applicable to
the Transaction Documents and the transactions contemplated therein; and (xviii) Company has performed due diligence and background
research on Investor and its affiliates including, without limitation, John M. Fife, and, to its satisfaction, has made inquiries
with respect to all matters Company may consider relevant to the undertakings and relationships contemplated by the Transaction
Documents including, among other things, the following: http://investing.businessweek.com/research/stocks/people/person.asp?personId=7505107&ticker=UAHC;
SEC Civil Case No. 07-C-0347 (N.D. Ill.); SEC Civil Action No. 07-CV-347 (N.D. Ill.); and FINRA Case #2011029203701. Company,
being aware of the matters described in subsection (xviii) above, acknowledges and agrees that such matters, or any similar matters,
have no bearing on the transactions contemplated by the Transaction Documents and covenants and agrees it will not use any such
information as a defense to performance of its obligations under the Transaction Documents or in any attempt to avoid, modify
or reduce such obligations.

 

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4.
Company Covenants. Until all of Company’s obligations under all of the Transaction Documents are paid and performed
in full, or within the timeframes otherwise specifically set forth below, Company will at all times comply with the following
covenants: (i) so long as Investor beneficially owns any of the Securities, Company will timely file on the applicable deadline
all reports required to be filed with the SEC pursuant to Sections 13 or 15(d) of the 1934 Act, and will take all reasonable action
under its control to ensure that adequate current public information with respect to Company, as required in accordance with Rule
144 of the 1933 Act, is publicly available, and will not terminate its status as an issuer required to file reports under the
1934 Act even if the 1934 Act or the rules and regulations thereunder would permit such termination; (ii) when issued, the Origination
Shares and Conversion Shares will be duly authorized, validly issued, fully paid for and non-assessable, free and clear of all
liens, claims, charges and encumbrances; (iii) the Common Stock shall be listed or quoted for trading on any of (a) NYSE, (b)
NASDAQ, (c) OTCQX, or (d) OTCQB; (iv) trading in Company’s Common Stock will not be suspended, halted, chilled, frozen,
reach zero bid or otherwise cease trading on Company’s principal trading market for a period of five (5) consecutive Trading
Days (as defined in the Note); and (v) Company will not make any Variable Security Issuances (as defined below) after the Closing
Date without Investor’s prior written consent, which consent may be granted or withheld in Investor’s sole and absolute
discretion. For purposes hereof, the term “Variable Security Issuance” means any issuance of any Company securities
that (A) have or may have conversion rights of any kind, contingent, conditional or otherwise, in which the number of shares that
may be issued pursuant to such conversion right varies with the market price of the Common Stock, (B) are issued to any person
or entity on the Restricted Investor List (as defined below) regardless of the terms, conditions or features of such securities,
or (C) are or may become convertible into Common Stock (including without limitation convertible debt, warrants or convertible
preferred stock), with a conversion price that varies with the market price of the Common Stock, even if such security only becomes
convertible following an event of default, the passage of time, or another trigger event or condition. For avoidance of doubt,
the issuance of shares of Common Stock under, pursuant to, in exchange for or in connection with any contract or instrument, whether
convertible or not, is deemed a Variable Security Issuance for purposes hereof if the number of shares of Common Stock to be issued
is based upon or related in any way to the market price of the Common Stock, including, but not limited to, Common Stock issued
in connection with a Section 3(a)(9) exchange, a Section 3(a)(10) settlement, or any other similar settlement or exchange. For
purposes hereof, the term “Restricted Investor List” means any person or entity listed on Exhibit G
or any affiliate, owner, member or shareholder of any person or entity listed on Exhibit G. Notwithstanding anything to
the contrary in the foregoing, “Variable Security Issuance” shall not include (1) any issuance of securities pursuant
to that certain Equity Distribution Agreement, dated July 23, 2012, between the Company and Maxim Group LLC; (2) any issuance
of securities pursuant to an underwritten securities offering; or (3) any issuance of securities to a person or entity on the
Restricted Investor List pursuant to an exercise or conversion of any warrant, option or convertible security that was in existence
as of the Closing Date.

 

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5.
Conditions to Company’s Obligation to Sell. The obligation of Company hereunder to issue and sell the Securities
to Investor at the Closing is subject to the satisfaction, on or before the Closing Date, of each of the following conditions:

 

5.1.
Investor shall have executed this Agreement and delivered the same to Company.

 

5.2.
Investor shall have delivered the Purchase Price to Company in accordance with Section 1.2 above.

 

6.
Conditions to Investor’s Obligation to Purchase. The obligation of Investor hereunder to purchase the Securities
at the Closing is subject to the satisfaction, on or before the Closing Date, of each of the following conditions, provided that
these conditions are for Investor’s sole benefit and may be waived by Investor at any time in its sole discretion:

 

6.1.
Company shall have executed this Agreement, the Security Agreement and the Note and delivered the same to Investor.

 

6.2.
Company shall have delivered to Investor a fully executed Irrevocable Letter of Instructions to Transfer Agent (the “TA
Letter”) substantially in the form attached hereto as Exhibit C acknowledged and agreed to in writing by Company’s
transfer agent (the “Transfer Agent”).

 

6.3.
Company shall have delivered to Investor a fully executed Secretary’s Certificate substantially in the form attached hereto
as Exhibit D evidencing Company’s approval of the Transaction Documents.

 

6.4.
Company shall have delivered to Investor a fully executed Share Issuance Resolution substantially in the form attached hereto
as Exhibit E to be delivered to the Transfer Agent.

 

6.5.
Company shall have delivered to Investor fully executed copies of all other Transaction Documents required to be executed by Company
herein or therein.

 

7.
Reservation of Shares. On the date hereof, Company will reserve 8,900,000 shares of Common Stock from its authorized and
unissued Common Stock to provide for all issuances of Common Stock under the Note (the “Share Reserve”). In
the event Investor returns the Origination Shares to Company, Company agrees to increase the Share Reserve by 500,000 within five
(5) Trading Days of its or its Transfer Agent’s receipt of the Origination Shares. Company further agrees to add additional
shares of Common Stock to the Share Reserve in increments of 1,000,000 shares as and when requested by Investor if as of the date
of any such request the number of shares being held in the Share Reserve is less than three (3) times the number of shares of
Common Stock obtained by dividing the Outstanding Balance (as defined in the Note) as of the date of the request by the Redemption
Conversion Price (as defined in the Note). Company shall further require the Transfer Agent to hold the shares of Common Stock
reserved pursuant to the Share Reserve exclusively for the benefit of Investor and to issue such shares to Investor promptly upon
Investor’s delivery of a conversion notice under the Note. Notwithstanding anything to the contrary contained herein, the
Company shall not be obligated to reserve, in the aggregate, shares of Common Stock pursuant to this Section 7 in excess of 19.99%
of the number of shares of Common Stock issued and outstanding on the Closing Date until such time the Approval (as defined in
the Note) has been obtained.

 

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8.
Miscellaneous. The provisions set forth in this Section 8 shall apply to this Agreement, as well as all other Transaction
Documents as if these terms were fully set forth therein; provided, however, that in the event there is a conflict between any
provision set forth in this Section 8 and any provision in any other Transaction Document, the provision in such other Transaction
Document shall govern.

 

8.1.
Arbitration of Claims. The parties shall submit all Claims (as defined in Exhibit F) arising under this Agreement
or any other Transaction Document or any other agreement between the parties and their affiliates or any Claim relating to the
relationship of the parties to binding arbitration pursuant to the arbitration provisions set forth in Exhibit F attached
hereto (the “Arbitration Provisions”). For the avoidance of doubt, the parties agree that the injunction described
in Section 8.3 below may be pursued in an arbitration that is separate and apart from any other arbitration regarding all other
Claims arising under the Transaction Documents. The parties hereby acknowledge and agree that the Arbitration Provisions are unconditionally
binding on the parties hereto and are severable from all other provisions of this Agreement. By executing this Agreement, Company
represents, warrants and covenants that Company has reviewed the Arbitration Provisions carefully, consulted with legal counsel
about such provisions (or waived its right to do so), understands that the Arbitration Provisions are intended to allow for the
expeditious and efficient resolution of any dispute hereunder, agrees to the terms and limitations set forth in the Arbitration
Provisions, and that Company will not take a position contrary to the foregoing representations. Company acknowledges and agrees
that Investor may rely upon the foregoing representations and covenants of Company regarding the Arbitration Provisions.

 

8.2.
Governing Law; Venue. This Agreement shall be construed and enforced in accordance with, and all questions concerning the
construction, validity, interpretation and performance of this Agreement shall be governed by, the internal laws of the State
of Utah, without giving effect to any choice of law or conflict of law provision or rule (whether of the State of Utah or any
other jurisdiction) that would cause the application of the laws of any jurisdiction other than the State of Utah. Each party
consents to and expressly agrees that the exclusive venue for arbitration of any dispute arising out of or relating to any Transaction
Document or the relationship of the parties or their affiliates shall be in Salt Lake County, Utah. Without modifying the parties’
obligations to resolve disputes hereunder pursuant to the Arbitration Provisions, for any litigation arising in connection with
any of the Transaction Documents (and notwithstanding the terms (specifically including any governing law and venue terms) of
any transfer agent services agreement or other agreement between the Transfer Agent and Company, such litigation specifically
includes, without limitation any action between or involving Company and the Transfer Agent under the TA Letter or otherwise related
to Investor in any way (specifically including, without limitation, any action where Company seeks to obtain an injunction, temporary
restraining order, or otherwise prohibit the Transfer Agent from issuing shares of Common Stock to Investor for any reason)),
each party hereto hereby (i) consents to and expressly submits to the exclusive personal jurisdiction of any state or federal
court sitting in Salt Lake County, Utah, (ii) expressly submits to the exclusive venue of any such court for the purposes hereof,
(iii) agrees to not bring any such action (specifically including, without limitation, any action where Company seeks to obtain
an injunction, temporary restraining order, or otherwise prohibit the Transfer Agent from issuing shares of Common Stock to Investor
for any reason) outside of any state or federal court sitting in Salt Lake County, Utah, and (iv) waives any claim of improper
venue and any claim or objection that such courts are an inconvenient forum or any other claim, defense or objection to the bringing
of any such proceeding in such jurisdiction or to any claim that such venue of the suit, action or proceeding is improper. Finally,
Company covenants and agrees to name Investor as a party in interest in, and provide written notice to Investor in accordance
with Section 8.9 below prior to bringing or filing, any action (including without limitation any filing or action against any
person or entity that is not a party to this Agreement, including without limitation the Transfer Agent) that is related in any
way to the Transaction Documents or any transaction contemplated herein or therein, including without limitation any action brought
by Company to enjoin or prevent the issuance of any shares of Common Stock to Investor by the Transfer Agent, and further agrees
to timely name Investor as a party to any such action. Company acknowledges that the governing law and venue provisions set forth
in this Section 8.2 are material terms to induce Investor to enter into the Transaction Documents and that but for Company’s
agreements set forth in this Section 8.2 Investor would not have entered into the Transaction Documents.

 

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8.3.
Specific Performance. Company acknowledges and agrees Investor may suffer irreparable harm in the event that Company fails
to perform any material provision of this Agreement or any of the other Transaction Documents in accordance with its specific
terms. It is accordingly agreed that Investor shall be entitled to one or more injunctions to prevent or cure breaches of the
provisions of this Agreement or such other Transaction Document and to enforce specifically the terms and provisions hereof or
thereof, this being in addition to any other remedy to which the Investor may be entitled under the Transaction Documents, at
law or in equity. Company specifically agrees that following an Event of Default (as defined in the Note) under the Note, Investor
shall have the right to seek and receive injunctive relief from a court or an arbitrator prohibiting Company from issuing any
of its common or preferred stock to any party unless the Note is being paid in full simultaneously with such issuance. For the
avoidance of doubt, in the event Investor seeks to obtain an injunction from a court or an arbitrator against Company or specific
performance of any provision of any Transaction Document, such action shall not be a waiver of any right of Investor under any
Transaction Document, at law, or in equity, including without limitation its rights to arbitrate any Claim pursuant to the terms
of the Transaction Documents, nor shall Investor’s pursuit of an injunction prevent Investor, under the doctrines of claim
preclusion, issues preclusion, res judicata or other similar legal doctrines, from pursuing other Claims in the future in a separate
arbitration.

 

8.4.
Counterparts. Each Transaction Document may be executed in any number of counterparts, each of which shall be deemed an
original, but all of which together shall constitute one instrument. The parties hereto confirm that any electronic copy of another
party’s executed counterpart of a Transaction Document (or such party’s signature page thereof) will be deemed to
be an executed original thereof.

 

8.5.
Headings. The headings of this Agreement are for convenience of reference only and shall not form part of, or affect the
interpretation of, this Agreement.

 

8.6.
Severability. In the event that any provision of this Agreement is invalid or unenforceable under any applicable statute
or rule of law, then such provision shall be deemed inoperative to the extent that it may conflict therewith and shall be deemed
modified to conform to such statute or rule of law. Any provision hereof which may prove invalid or unenforceable under any law
shall not affect the validity or enforceability of any other provision hereof.

 

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8.7.
Entire Agreement. This Agreement, together with the other Transaction Documents, contains the entire understanding of the
parties with respect to the matters covered herein and therein and, except as specifically set forth herein or therein, neither
Company nor Investor makes any representation, warranty, covenant or undertaking with respect to such matters. For the avoidance
of doubt, all prior term sheets or other documents between Company and Investor, or any affiliate thereof, related to the transactions
contemplated by the Transaction Documents (collectively, “Prior Agreements”), that may have been entered into
between Company and Investor, or any affiliate thereof, are hereby null and void and deemed to be replaced in their entirety by
the Transaction Documents. To the extent there is a conflict between any term set forth in any Prior Agreement and the term(s)
of the Transaction Documents, the Transaction Documents shall govern.

 

8.8.
Amendments. No provision of this Agreement may be waived or amended other than by an instrument in writing signed by both
parties hereto.

 

8.9.
Notices. Any notice required or permitted hereunder shall be given in writing (unless otherwise specified herein) and shall
be deemed effectively given on the earliest of: (i) the date delivered, if delivered by personal delivery as against written receipt
therefor or by email to an executive officer named below or such officer’s successor, or by facsimile (with successful transmission
confirmation which is kept by sending party), (ii) the earlier of the date delivered or the third Trading Day after deposit, postage
prepaid, in the United States Postal Service by certified mail, or (iii) the earlier of the date delivered or the third Trading
Day after mailing by express courier, with delivery costs and fees prepaid, in each case, addressed to each of the other parties
thereunto entitled at the following addresses (or at such other addresses as such party may designate by five (5) calendar days’
advance written notice similarly given to each of the other parties hereto):

 

	 	If to Company:
	 	 	 
	 	 	Hemispherx
    Biopharma, Inc.
	 	 	Attn:
    Thomas Equels
	 	 	2117
    SW Highway 484
	 	 	Ocala,
    Florida 34473
	 	 	Facsimile:
	 	 	 
	 	With a copy to:
	 	 	 
	 	 	Hemispherx
    Biopharma, Inc.
	 	 	Attn:
    Adam Pascale
	 	 	600
    Main Street, Suite 2
	 	 	Riverton,
    NJ 08077
	 	 	Facsimile:
	 	 	 
	 	If to Investor:
	 	 	 
	 	 	Iliad
    Research and Trading, L.P.
	 	 	Attn:
    John Fife
	 	 	303
    East Wacker Drive, Suite 1040
	 	 	Chicago,
    Illinois 60601
	 	 	Facsimile:
	 	 	 
	 	With a copy to (which copy shall not constitute notice):
	 	 	 
	 	 	Hansen
    Black Anderson Ashcraft PLLC
	 	 	Attn:
    Jonathan Hansen
	 	 	3051
    West Maple Loop Drive, Suite 325
	 	 	Lehi,
    Utah 84043

 

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8.10.
Successors and Assigns. This Agreement or any of the severable rights and obligations inuring to the benefit of or to be
performed by Investor hereunder may be assigned by Investor to a third party, including its affiliates, in whole or in part, without
the need to obtain Company’s consent thereto. Company may not assign its rights or obligations under this Agreement or delegate
its duties hereunder without the prior written consent of Investor.

 

8.11.
Survival. The representations and warranties of Company and the agreements and covenants set forth in this Agreement shall
survive the Closing hereunder notwithstanding any due diligence investigation conducted by or on behalf of Investor. Company agrees
to indemnify and hold harmless Investor and all its officers, directors, employees, attorneys, and agents for loss or damage arising
as a result of or related to any breach or alleged breach by Company of any of its representations, warranties and covenants set
forth in this Agreement or any of its covenants and obligations under this Agreement, including advancement of expenses as they
are incurred.

 

8.12.
Further Assurances. Each party shall do and perform, or cause to be done and performed, all such further acts and things,
and shall execute and deliver all such other agreements, certificates, instruments and documents, as the other party may reasonably
request in order to carry out the intent and accomplish the purposes of this Agreement and the consummation of the transactions
contemplated hereby.

 

8.13.
Investor’s Rights and Remedies Cumulative. All rights, remedies, and powers conferred in this Agreement and the Transaction
Documents are cumulative and not exclusive of any other rights or remedies, and shall be in addition to every other right, power,
and remedy that Investor may have, whether specifically granted in this Agreement or any other Transaction Document, or existing
at law, in equity, or by statute, and any and all such rights and remedies may be exercised from time to time and as often and
in such order as Investor may deem expedient.

 

8.14.
Attorneys’ Fees and Cost of Collection. In the event of any arbitration or action at law or in equity to enforce
or interpret the terms of this Agreement or any of the other Transaction Documents, the parties agree that the party who is awarded
the most money (which, for the avoidance of doubt, shall be determined without regard to any statutory fines, penalties, fees,
or other charges awarded to any party) shall be deemed the prevailing party for all purposes and shall therefore be entitled to
an additional award of the full amount of the attorneys’ fees, deposition costs, and expenses paid by such prevailing party
in connection with arbitration or litigation without reduction or apportionment based upon the individual claims or defenses giving
rise to the fees and expenses. Nothing herein shall restrict or impair an arbitrator’s or a court’s power to award
fees and expenses for frivolous or bad faith pleading. If (i) the Note is placed in the hands of an attorney for collection or
enforcement prior to commencing arbitration or legal proceedings, or is collected or enforced through any arbitration or legal
proceeding, or Investor otherwise takes action to collect amounts due under the Note or to enforce the provisions of the Note,
or (ii) there occurs any bankruptcy, reorganization, receivership of Company or other proceedings affecting Company’s creditors’
rights and involving a claim under the Note; then Company shall pay the costs incurred by Investor for such collection, enforcement
or action or in connection with such bankruptcy, reorganization, receivership or other proceeding, including, without limitation,
attorneys’ fees, expenses, deposition costs, and disbursements.

 

8.15.
Waiver. No waiver of any provision of this Agreement shall be effective unless it is in the form of a writing signed by
the party granting the waiver. No waiver of any provision or consent to any prohibited action shall constitute a waiver of any
other provision or consent to any other prohibited action, whether or not similar. No waiver or consent shall constitute a continuing
waiver or consent or commit a party to provide a waiver or consent in the future except to the extent specifically set forth in
writing.

 

    	 	9	 

    	 

    

 

8.16.
Waiver of Jury Trial. EACH PARTY TO THIS AGREEMENT IRREVOCABLY WAIVES ANY AND ALL RIGHTS SUCH PARTY MAY HAVE TO DEMAND
THAT ANY ACTION, PROCEEDING OR COUNTERCLAIM ARISING OUT OF OR IN ANY WAY RELATED TO THIS AGREEMENT, ANY OTHER TRANSACTION DOCUMENT,
OR THE RELATIONSHIPS OF THE PARTIES HERETO BE TRIED BY JURY. THIS WAIVER EXTENDS TO ANY AND ALL RIGHTS TO DEMAND A TRIAL BY JURY
ARISING UNDER COMMON LAW OR ANY APPLICABLE STATUTE, LAW, RULE OR REGULATION. FURTHER, EACH PARTY HERETO ACKNOWLEDGES THAT SUCH
PARTY IS KNOWINGLY AND VOLUNTARILY WAIVING SUCH PARTY’S RIGHT TO DEMAND TRIAL BY JURY.

 

8.17.
Time is of the Essence. Time is expressly made of the essence with respect to each and every provision of this Agreement
and the other Transaction Documents.

 

8.18.
Voluntary Agreement. Company has carefully read this Agreement and each of the other Transaction Documents and has asked
any questions needed for Company to understand the terms, consequences and binding effect of this Agreement and each of the other
Transaction Documents and fully understand them. Company has had the opportunity to seek the advice of an attorney of Company’s
choosing, or has waived the right to do so, and is executing this Agreement and each of the other Transaction Documents voluntarily
and without any duress or undue influence by Investor or anyone else.

 

[Remainder
of page intentionally left blank; signature page follows]

 

    	 	10	 

    	 

    

 

IN
WITNESS WHEREOF, the undersigned Investor and Company have caused this Agreement to be duly executed as of the date first above
written.

 

SUBSCRIPTION
AMOUNT:

 

	Principal
    Amount of Note:	$3,170,000.00
	 	 
	Purchase
    Price:	$3,000,000.00

 

	 	INVESTOR:
	 	 	 	 	 
	 	Iliad
    Research and Trading, L.P.
	 	 	 	 	 
	 	By:	Iliad
    Management, LLC, its General Partner
	 	 	 	 	 
	 	 	By:	Fife
    Trading, Inc., its Manager
	 	 	 	 	 
	 	 	 	By:	/s/
    John M. Fife
	 	 	 	 	John
    M. Fife, President

 

	 	COMPANY:
	 	 	 
	 	Hemispherx Biopharma, Inc.
	 	 	 
	 	By:	/s/
    Tom Equels

	 	Printed
    Name: 	Tom
    Equels

	 	Title:	CEO/PRES

 

[Signature
Page to Securities Purchase Agreement]NEITHER
THESE SECURITIES NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE CONVERTIBLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE
COMMISSION 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

 

SECURED
CONVERTIBLE PROMISSORY NOTE 

 

	Effective
    Date: September 28, 2018	U.S.
    $3,170,000.00

 

FOR
VALUE RECEIVED, Hemispherx Biopharma, Inc., a Delaware corporation (“Borrower”),
promises to pay to Iliad Research and Trading, L.P., a Utah limited partnership,
or its successors or assigns (“Lender”), $3,170,000.00 and any interest, fees, charges, and late fees accrued
hereunder on the date that is twelve (12) months after the Purchase Price Date (the “Maturity Date”) in accordance
with the terms set forth herein and to pay interest on the Outstanding Balance at the rate of ten percent (10%) per annum from
the Purchase Price Date until the same is paid in full. This Secured Convertible Promissory Note (this “Note”)
is issued and made effective as of September 28, 2018 (the “Effective Date”). This Note is issued pursuant
to that certain Securities Purchase Agreement dated September 28, 2018, as the same may be amended from time to time, by and between
Borrower and Lender (the “Purchase Agreement”). Certain capitalized terms used herein are defined in Attachment
1 attached hereto and incorporated herein by this reference.

 

This
Note carries an OID of $150,000.00. In addition, Borrower agrees to pay $20,000.00 to Lender to cover Lender’s legal fees,
accounting costs, due diligence, monitoring and other transaction costs incurred in connection with the purchase and sale of this
Note (the “Transaction Expense Amount”), all of which amount is included in the initial principal balance of
this Note. The purchase price for this Note shall be $3,000,000.00 (the “Purchase Price”), computed as follows:
$3,170,000.00 original principal balance, less the OID, less the Transaction Expense Amount. The Purchase Price shall be payable
by Lender by wire transfer of immediately available funds.

 

1.
Payment; Prepayment.

 

1.1.
Payment. All payments owing hereunder shall be in lawful money of the United States of America or Conversion Shares (as
defined below), as provided for herein, and delivered to Lender at the address or bank account furnished to Borrower for that
purpose. All payments shall be applied first to (a) costs of collection, if any, then to (b) fees and charges, if any, then to
(c) accrued and unpaid interest, and thereafter, to (d) principal.

 

1.2.
Prepayment. Notwithstanding the foregoing, Borrower shall have the right to prepay all or any portion of the Outstanding
Balance (less such portion of the Outstanding Balance for which Borrower has received a Lender Conversion Notice (as defined below)
or a Redemption Notice (as defined below) from Lender where the applicable Conversion Shares have not yet been delivered. If Borrower
exercises its right to prepay this Note, Borrower shall make payment to Lender of an amount in cash equal to 115% multiplied by
the portion of the Outstanding Balance Borrower elects to repay.

 

2.
Security. This Note is secured by that certain Security Agreement of even date herewith, as the same may be amended from
time to time (the “Security Agreement”), executed by Borrower in favor of Lender encumbering certain of Borrower’s
assets, as more specifically set forth in the Security Agreement, all the terms and conditions of which are hereby incorporated
into and made a part of this Note.

 

    	 	 	 

     

    

 

3.
Lender Optional Conversion.

 

3.1.
Lender Conversions. Subject to Sections 12 and 13 below, Lender has the right at any time after the Purchase Price Date
until the Outstanding Balance has been paid in full, at its election, to convert (“Lender Conversion”) all
or any portion of the Outstanding Balance into shares (each instance of conversion is referred herein as a “Lender Conversion
Shares”) of fully paid and non-assessable common stock, $0.001 par value per share (“Common Stock”),
of Borrower as per the following conversion formula: the number of Lender Conversion Shares equals the amount being converted
(the “Conversion Amount”) divided by the Lender Conversion Price (as defined below). Conversion notices in
the form attached hereto as Exhibit A (each, a “Lender Conversion Notice”) may be effectively delivered
to Borrower by any method set forth in Section 8.9 of the Purchase Agreement, and all Lender Conversions shall be cashless and
not require further payment from Lender. Borrower shall deliver the Lender Conversion Shares from any Lender Conversion to Lender
in accordance with Section 9 below.

 

3.2.
Lender Conversion Price. Subject to adjustment as set forth in this Note, the price at which Lender has the right to convert
all or any portion of the Outstanding Balance into Common Stock is $0.30 per share of Common Stock (the “Lender Conversion
Price”).

 

4.
Defaults and Remedies.

 

4.1.
Defaults. The following are events of default under this Note (each, an “Event of Default”): (a) Borrower
fails to pay any principal, interest, fees, charges, or any other amount when due and payable hereunder; (b) subject to Section
12 and 13 below, Borrower fails to deliver any Lender Conversion Shares in accordance with the terms hereof and such default continues
for two (2) Trading Days after written notice to Company by Lender of such default; (c) subject to Section 12 and 13 below, Borrower
fails to deliver any Redemption Conversion Shares (as defined below) in accordance with the terms hereof and such default continues
for two (2) Trading Days after written notice to Company by Lender of such default; (d) a receiver, trustee or other similar official
shall be appointed over Borrower or a material part of its assets and such appointment shall remain uncontested for twenty (20)
days or shall not be dismissed or discharged within sixty (60) days; (e) Borrower admits in writing its inability to pay, its
debts as they become due, subject to applicable grace periods, if any; (f) Borrower makes a general assignment for the benefit
of creditors; (g) Borrower files a petition for relief under any bankruptcy, insolvency or similar law (domestic or foreign);
(h) an involuntary bankruptcy proceeding is commenced or filed against Borrower and is not dismissed within sixty (60) days; (i)
Borrower or any pledgor, trustor, or guarantor of this Note defaults or otherwise fails to observe or perform any covenant, obligation,
condition or agreement of Borrower or such pledgor, trustor, or guarantor contained herein or in any other Transaction Document
(as defined in the Purchase Agreement), other than those specifically set forth in this Section 4.1 and Section 4 of the Purchase
Agreement and such default or failure remains uncured for a period of ten (10) days after written notice to Company by Lender
of such default or failure; (j) any representation, warranty or other statement made or furnished by or on behalf of Borrower
or any pledgor, trustor, or guarantor of this Note to Lender herein, in any Transaction Document, or otherwise in connection with
the issuance of this Note is false, incorrect, incomplete or misleading in any material respect when made or furnished; (k) the
occurrence of a Fundamental Transaction without Lender’s prior written consent; (l) Borrower fails to maintain the Share
Reserve (as defined in the Purchase Agreement) as required under the Purchase Agreement and such failure continues for five (5)
days after written notice to Company by Lender of such failure; (m) Borrower effectuates a reverse split of its Common Stock without
twenty (20) Trading Days prior written notice to Lender; (n) any money judgment, writ or similar process is entered or filed against
Borrower or any subsidiary of Borrower or any of its property or other assets for more than $1,000,000.00, and shall remain unvacated,
unbonded or unstayed for a period of twenty (20) calendar days unless otherwise consented to by Lender; (o) Borrower fails to
be DWAC Eligible at any time after the six (6) month anniversary of the Closing and such failure continues for ten (10) days after
written notice to Company by Lender of such failure; (p) [intentionally omitted]; (q) Borrower fails to observe or perform any
covenant set forth in Section 4 of the Purchase Agreement (other than the covenant with respect to Unapproved Variable Security
Issuances); or (r) Borrower makes any Unapproved Variable Security Issuance.

 

    	 	2	 

     

    

 

4.2.
Remedies. At any time and from time to time after Lender becomes aware of the occurrence of any Event of Default, Lender
may accelerate this Note by written notice to Borrower, with the Outstanding Balance becoming immediately due and payable in cash
at the Mandatory Default Amount. Notwithstanding the foregoing, at any time following the occurrence of any Event of Default,
Lender may, at its option, elect to increase the Outstanding Balance by applying the Default Effect (subject to the limitation
set forth below) via written notice to Borrower without accelerating the Outstanding Balance, in which event the Outstanding Balance
shall be increased as of the date of the occurrence of the applicable Event of Default pursuant to the Default Effect, but the
Outstanding Balance shall not be immediately due and payable unless so declared by Lender (for the avoidance of doubt, if Lender
elects to apply the Default Effect pursuant to this sentence, it shall reserve the right to declare the Outstanding Balance immediately
due and payable at any time and no such election by Lender shall be deemed to be a waiver of its right to declare the Outstanding
Balance immediately due and payable as set forth herein unless otherwise agreed to by Lender in writing). Notwithstanding the
foregoing, upon the occurrence of any Event of Default described in clauses (d), (e), (f), (g) or (h) of Section 4.1, the Outstanding
Balance as of the date of acceleration shall become immediately and automatically due and payable in cash at the Mandatory Default
Amount, without any written notice required by Lender. At any time following the occurrence of any Event of Default, upon written
notice given by Lender to Borrower, interest shall accrue on the Outstanding Balance beginning on the date the applicable Event
of Default occurred at an interest rate equal to the lesser of 22% per annum or the maximum rate permitted under applicable law
(“Default Interest”). For the avoidance of doubt, Lender may continue making Lender Conversions and Redemption
Conversions (as defined below) at any time following an Event of Default until such time as the Outstanding Balance is paid in
full. In connection with acceleration described herein, Lender need not provide, and Borrower hereby waives, any presentment,
demand, protest or other notice of any kind, and Lender may immediately and without expiration of any grace period enforce any
and all of its rights and remedies hereunder and all other remedies available to it under applicable law. Such acceleration may
be rescinded and annulled by Lender at any time prior to payment hereunder and Lender shall have all rights as a holder of the
Note until such time, if any, as Lender receives full payment pursuant to this Section 4.2. No such rescission or annulment shall
affect any subsequent Event of Default or impair any right consequent thereon. Nothing herein shall limit Lender’s right
to pursue any other remedies available to it at law or in equity including, without limitation, a decree of specific performance
and/or injunctive relief with respect to Borrower’s failure to timely deliver Conversion Shares upon Conversion of the Note
as required pursuant to the terms hereof.

 

5.
Unconditional Obligation; No Offset. Borrower acknowledges that this Note is an unconditional, valid, binding and enforceable
obligation of Borrower not subject to offset, deduction or counterclaim of any kind. Borrower hereby waives any rights of offset
it now has or may have hereafter against Lender, its successors and assigns, and agrees to make the payments or Conversions called
for herein in accordance with the terms of this Note.

 

6.
Waiver. No waiver of any provision of this Note shall be effective unless it is in the form of a writing signed by the
party granting the waiver. No waiver of any provision or consent to any prohibited action shall constitute a waiver of any other
provision or consent to any other prohibited action, whether or not similar. No waiver or consent shall constitute a continuing
waiver or consent or commit a party to provide a waiver or consent in the future except to the extent specifically set forth in
writing.

 

    	 	3	 

     

    

 

7.
Adjustment of Lender Conversion Price upon Subdivision or Combination of Common Stock. Without limiting any provision hereof,
if Borrower at any time on or after the Effective Date subdivides (by any stock split, stock dividend, recapitalization or otherwise)
one or more classes of its outstanding shares of Common Stock into a greater number of shares, the Lender Conversion Price in
effect immediately prior to such subdivision will be proportionately reduced. Without limiting any provision hereof, if Borrower
at any time on or after the Effective Date combines (by combination, reverse stock split or otherwise) one or more classes of
its outstanding shares of Common Stock into a smaller number of shares, the Lender Conversion Price in effect immediately prior
to such combination will be proportionately increased. Any adjustment pursuant to this Section 7 shall become effective immediately
after the effective date of such subdivision or combination. If any event requiring an adjustment under this Section 7 occurs
during the period that a Lender Conversion Price is calculated hereunder, then the calculation of such Lender Conversion Price
shall be adjusted appropriately to reflect such event.

 

8.
Borrower Redemptions.

 

8.1.
Redemption Conversion Price. Subject to the adjustments set forth herein, the conversion price for each Redemption Conversion
(the “Redemption Conversion Price”) shall be the lesser of (a) the Lender Conversion Price, and (b) the Market
Price.

 

8.2.
Redemption Conversions. Beginning on the date that is six (6) months from the Purchase Price Date, Lender shall have the
right, exercisable at any time in its sole and absolute discretion, to redeem all or any portion of the Note (such amount, the
“Redemption Amount”) by providing Borrower with a notice substantially in the form attached hereto as Exhibit
B (each, a “Redemption Notice”, and each date on which Lender delivers a Redemption Notice, a “Redemption
Date”). For the avoidance of doubt, Lender may submit to Borrower one (1) or more Redemption Notices in any given calendar
month. Payments of each Redemption Amount may be made (a) in cash, or (b) by converting such Redemption Amount into shares of
Common Stock (“Redemption Conversion Shares”, and together with the Lender Conversion Shares, the “Conversion
Shares”) in accordance with this Section 8.2 (each, a “Redemption Conversion”) per the following
formula: the number of Redemption Conversion Shares equals the portion of the applicable Redemption Amount being converted divided
by the Redemption Conversion Price, or (c) by any combination of the foregoing, so long as the cash is delivered to Lender on
the third (3rd) Trading Day immediately following the applicable Redemption Date and the Redemption Conversion Shares
are delivered to Lender on or before the applicable Delivery Date (as defined below). Notwithstanding that failure to repay this
Note in full by the Maturity Date is an Event of Default, the Redemption Dates shall continue after the Maturity Date pursuant
to this Section 8.2 until the Outstanding Balance is repaid in full.

 

8.3.
Allocation of Redemption Amounts. Following its receipt of a Redemption Notice, Borrower may either ratify Lender’s
proposed allocation in the applicable Redemption Notice or elect to change the allocation by written notice to Lender by email
or fax by the end of the next Trading Day immediately following the date of delivery of such Redemption Notice, with a copy of
such written notice to the transfer agent of the Common Stock, so long as the sum of the cash payments and the amount of Redemption
Conversions equal the applicable Redemption Amount. If Borrower fails to notify Lender of its election to change the allocation
prior to the deadline set forth in the previous sentence, it shall be deemed to have ratified and accepted the allocation set
forth in the applicable Redemption Notice prepared by Lender. Borrower acknowledges and agrees that the amounts and calculations
set forth thereon are subject to correction or adjustment because of error, mistake, or any adjustment resulting from an Event
of Default or other adjustment permitted under the Transaction Documents (an “Adjustment”). Furthermore, no
error or mistake in the preparation of such notices, or failure to apply any Adjustment that could have been applied prior to
the preparation of a Redemption Notice may be deemed a waiver of Lender’s right to enforce the terms of any Note, even if
such error, mistake, or failure to include an Adjustment arises from Lender’s own calculation. Borrower shall deliver the
Redemption Conversion Shares from any Redemption Conversion to Lender in accordance with Section 9 below on or before each applicable
Delivery Date.

 

    	 	4	 

     

    

 

9.
Method of Conversion Share Delivery. On or before the close of business on the third (3rd) Trading Day following
each Redemption Date or the third (3rd) Trading Day following the date of delivery of a Lender Conversion Notice, as
applicable (the “Delivery Date”), Borrower shall, provided it is DWAC Eligible at such time and such Conversion
Shares are eligible for delivery via DWAC, deliver or cause its transfer agent to deliver the applicable Conversion Shares electronically
via DWAC to the account designated by Lender in the applicable Lender Conversion Notice or Redemption Notice. If Borrower is not
DWAC Eligible or such Conversion Shares are not eligible for delivery via DWAC, it shall deliver to Lender or its broker (as designated
in the Lender Conversion Notice or Redemption Notice), via reputable overnight courier, a certificate representing the number
of shares of Common Stock equal to the number of Conversion Shares to which Lender shall be entitled, registered in the name of
Lender or its designee. For the avoidance of doubt, Borrower has not met its obligation to deliver Conversion Shares by the Delivery
Date unless Lender or its broker, as applicable, has actually received the certificate representing the applicable Conversion
Shares no later than the close of business on the relevant Delivery Date pursuant to the terms set forth above. Moreover, and
notwithstanding anything to the contrary herein or in any other Transaction Document, in the event Borrower or its transfer agent
refuses to deliver any Conversion Shares without a restrictive securities legend to Lender on grounds that such issuance is in
violation of Rule 144 under the Securities Act of 1933, as amended (“Rule 144”), Borrower shall deliver or
cause its transfer agent to deliver the applicable Conversion Shares to Lender with a restricted securities legend, but otherwise
in accordance with the provisions of this Section 9. In conjunction therewith, Borrower will also deliver to Lender a written
explanation from its counsel or its transfer agent’s counsel opining as to why the issuance of the applicable Conversion
Shares violates Rule 144; provided, Lender acknowledges that any Conversion Shares issued prior to the six (6) month anniversary
of the Closing Date will bear a restrictive securities legend, and Borrower shall have no obligation to deliver such opinion letter
for any Conversion occurring prior to the six (6) month anniversary of the Closing Date.

 

10.
Conversion Delays. If Borrower fails to deliver Conversion Shares in accordance with the timeframe stated in Section 9,
Lender may at any time prior to receiving the applicable Conversion Shares rescind in whole or in part such Conversion, with a
corresponding increase to the Outstanding Balance (any returned amount will tack back to the Purchase Price Date for purposes
of determining the holding period under Rule 144). In addition, for each Conversion, in the event that Conversion Shares are not
delivered by the third (3rd) Trading Day (inclusive of the day of the Conversion), a late fee equal to 2% of the applicable
Conversion Share Value rounded to the nearest multiple of $100.00 but with a floor of $500.00 per day (but in any event the cumulative
amount of such late fees for each Conversion shall not exceed 200% of the applicable Conversion Share Value) will be assessed
for each day after the third (3rd) Trading Day (inclusive of the day of the Conversion) until Conversion Share delivery
is made; and such late fee will be added to the Outstanding Balance (such fees, the “Conversion Delay Late Fees”).

 

11.
Approved Variable Security Issuance. The Outstanding Balance will automatically be increased by five percent (5%) for each
Approved Variable Security Issuance made by Borrower (without the need for Lender to provide any notice to Borrower of such increase),
which increase will be effective as of the date of each applicable Approved Variable Security Issuance.

 

12.
Ownership Limitation. Notwithstanding anything to the contrary contained in this Note or the other Transaction Documents,
the Company shall not effect any conversion of this Note, and Lender shall not have the right to convert any portion of this Note,
and shall not deliver a Conversion Notice, to the extent that after giving effect to such conversion would cause Lender (together
with its affiliates) to beneficially own a number of shares exceeding 4.99% of the number of shares of Common Stock outstanding
on such date (including for such purpose the shares of Common Stock issuable upon such issuance) (the “Maximum Percentage”).
For purposes of this section, beneficial ownership of Common Stock will be determined pursuant to Section 13(d) of the 1934 Act.
Notwithstanding the forgoing, the term “4.99%” above shall be replaced with “9.99%” at such time as the
Market Capitalization is less than $10,000,000.00. Notwithstanding any other provision contained herein, if the term “4.99%”
is replaced with “9.99%” pursuant to the preceding sentence, such increase to “9.99%” shall remain at
9.99% until increased, decreased or waived by Lender as set forth below. By written notice to Borrower, Lender may increase, decrease
or waive the Maximum Percentage as to itself but any such waiver will not be effective until the 61st day after delivery thereof.
The foregoing 61-day notice requirement is enforceable, unconditional and non-waivable and shall apply to all affiliates and assigns
of Lender.

 

    	 	5	 

     

    

 

13.
Issuance Cap. Notwithstanding anything to the contrary contained in this Note or the other Transaction Documents, Borrower
and Lender agree that the total cumulative number of shares of Common Stock issued to Lender hereunder together with all other
Transaction Documents may not exceed the requirements of NYSE Listing Rule 312.03(c) (“NYSE 19.99% Cap”), except
that such limitation will not apply following Approval (defined below). If the number of shares of Common Stock issued to Lender
reaches the NYSE 19.99% Cap, so as not to violate the 20% limit established in NYSE Listing Rule 312.03(c), Borrower will use
reasonable commercial efforts to obtain stockholder approval of the Note and the issuance of additional Conversion Shares, if
necessary, in accordance with the requirements of NYSE Listing Rule 312.03(c) (the “Approval”), and until the
Approval has been obtained, Lender shall not submit any Conversion Notice to the extent after giving effect to such conversion
would exceed the NYSE 19.99% Cap. If the Borrower is unable to obtain such Approval, any remaining Outstanding Balance of this
Note must be repaid in cash.

 

14.
Opinion of Counsel. In the event that an opinion of counsel is needed for any matter related to this Note, Lender has the
right to have any such opinion provided by its counsel.

 

15.
Governing Law; Venue. This Note shall be construed and enforced in accordance with, and all questions concerning the construction,
validity, interpretation and performance of this Note shall be governed by, the internal laws of the State of Utah, without giving
effect to any choice of law or conflict of law provision or rule (whether of the State of Utah or any other jurisdiction) that
would cause the application of the laws of any jurisdiction other than the State of Utah. The provisions set forth in the Purchase
Agreement to determine the proper venue for any disputes are incorporated herein by this reference.

 

16.
Arbitration of Disputes. By its issuance or acceptance of this Note, each party agrees to be bound by the Arbitration Provisions
(as defined in the Purchase Agreement) set forth as an exhibit to the Purchase Agreement.

 

17.
Cancellation. After repayment or conversion of the entire Outstanding Balance, this Note shall be deemed paid in full,
shall automatically be deemed canceled, and shall not be reissued.

 

18.
Amendments. The prior written consent of both parties hereto shall be required for any change or amendment to this Note.

 

19.
Assignments. Borrower may not assign this Note without the prior written consent of Lender. Subject to compliance with
any applicable securities laws and the immediately following sentence, this Note and any shares of Common Stock issued upon conversion
of this Note may be offered, sold, assigned or transferred by Lender without the consent of Borrower. If at the time of any transfer
of this Note or any shares of Common Stock issued upon conversion of this Note, the transfer of such Securities shall not be either
(i) registered pursuant to an effective registration statement under the 1933 Act and under applicable state securities or blue
sky laws or (ii) eligible for resale without volume or manner-of-sale restrictions or current public information requirements
pursuant to Rule 144, the Company may require, as a condition of allowing such transfer, that Lender or transferee, as the case
may be, comply with the transfer restrictions set forth on the restrictive legend on the face of such Security.

 

    	 	6	 

     

    

 

20.
Notices. Whenever notice is required to be given under this Note, unless otherwise provided herein, such notice shall be
given in accordance with the subsection of the Purchase Agreement titled “Notices.”

 

21.
Liquidated Damages. Lender and Borrower agree that in the event Borrower fails to comply with any of the terms or provisions
of this Note, Lender’s damages would be uncertain and difficult (if not impossible) to accurately estimate because of the
parties’ inability to predict future interest rates, future share prices, future trading volumes and other relevant factors.
Accordingly, Lender and Borrower agree that any fees, balance adjustments, Default Interest or other charges assessed under this
Note are not penalties but instead are intended by the parties to be, and shall be deemed, liquidated damages (under Lender’s
and Borrower’s expectations that any such liquidated damages will tack back to the Purchase Price Date for purposes of determining
the holding period under Rule 144).

 

22.
Severability. If any part of this Note is construed to be in violation of any law, such part shall be modified to achieve
the objective of Borrower and Lender to the fullest extent permitted by law and the balance of this Note shall remain in full
force and effect.

 

[Remainder
of page intentionally left blank; signature page follows]

 

    	 	7	 

     

    

 

IN
WITNESS WHEREOF, Borrower has caused this Note to be duly executed as of the Effective Date.

 

	 	BORROWER:
	 	 
	 	Hemispherx Biopharma, Inc.
	 	 	 
	 	By:	/s/
    Tom Equels
	 	Name: 
    	Tom
    Equels
	 	Title:	CEO/PRES

 

ACKNOWLEDGED,
ACCEPTED AND AGREED:

 

LENDER:

 

Iliad
Research and Trading, L.P.

 

	By: 	Iliad Management, LLC, its General Partner	 
	 	 	 	 	 
	 	By: 	Fife Trading, Inc., its Manager	 
	 	 	 	 	 
	 	 	By: 	/s/
    John M. Fife	 
	 	 	 	John
M. Fife, President 	 

 

[Signature
Page to Secured Convertible Promissory Note]

 

    	 	 	 

     

    

 

ATTACHMENT
1

DEFINITIONS

 

For
purposes of this Note, the following terms shall have the following meanings:

 

A1.
“Approved Variable Security Issuance” means a Variable Security Issuance (as defined in the Purchase Agreement)
for which Borrower received Lender’s written consent prior to the applicable issuance.

 

A2.
“Bloomberg” means Bloomberg L.P. (or if that service is not then reporting the relevant information regarding
the Common Stock, a comparable reporting service of national reputation selected by Lender and reasonably satisfactory to Borrower).

 

A3.
“Closing Bid Price” and “Closing Trade Price” means the last closing bid price and last
closing trade price, respectively, for the Common Stock on its principal market, as reported by Bloomberg, or, if its principal
market begins to operate on an extended hours basis and does not designate the closing bid price or the closing trade price (as
the case may be) then the last bid price or last trade price, respectively, of the Common Stock prior to 4:00:00 p.m., New York
time, as reported by Bloomberg, or, if its principal market is not the principal securities exchange or trading market for the
Common Stock, the last closing bid price or last trade price, respectively, of the Common Stock on the principal securities exchange
or trading market where the Common Stock is listed or traded as reported by Bloomberg, or if the foregoing do not apply, the last
closing bid price or last trade price, respectively, of the Common Stock in the over-the-counter market on the electronic bulletin
board for the Common Stock as reported by Bloomberg, or, if no closing bid price or last trade price, respectively, is reported
for the Common Stock by Bloomberg, the average of the bid prices, or the ask prices, respectively, of any market makers for the
Common Stock as reported by OTC Markets Group, Inc., and any successor thereto. If the Closing Bid Price or the Closing Trade
Price cannot be calculated for the Common Stock on a particular date on any of the foregoing bases, the Closing Bid Price or the
Closing Trade Price (as the case may be) of the Common Stock on such date shall be the fair market value as mutually determined
by Lender and Borrower. All such determinations shall be appropriately adjusted for any stock dividend, stock split, stock combination
or other similar transaction during such period.

 

A4.
“Conversion” means a Lender Conversion under Section 3 or a Redemption Conversion under Section 8.

 

A5.
“Conversion Factor” means 80%.

 

A6.
“Conversion Share Value” means the product of the number of Conversion Shares deliverable pursuant to any Conversion
Notice multiplied by the Closing Trade Price of the Common Stock on the Delivery Date for such Conversion.

 

A7.
“Default Effect” means multiplying the Outstanding Balance as of the date the applicable Event of Default occurred
by (a) fifteen percent (15%) for each occurrence of any Major Default, (b) ten percent (10%) for each occurrence of an Unapproved
Variable Security Issuance Default, or (c) five percent (5%) for each occurrence of any Minor Default, and then adding the resulting
product to the Outstanding Balance as of the date the applicable Event of Default occurred, with the sum of the foregoing then
becoming the Outstanding Balance under this Note as of the date the applicable Event of Default occurred; provided that the aggregate
amount of the Default Effect for all Major Defaults and Minor Defaults shall not exceed twenty-five percent (25%); and provided
further that the Default Effect shall not apply to any Event of Default pursuant to Section 4.1(b) hereof. There shall be no limit
on the number of times the Default Effect may be applied with respect to Unapproved Variable Security Issuance Defaults.

 

A8.
“DTC” means the Depository Trust Company or any successor thereto.

 

A9.
“DTC/FAST Program” means the DTC’s Fast Automated Securities Transfer program.

 

A10.
“DWAC” means the DTC’s Deposit/Withdrawal at Custodian system.

 

A11.
“DWAC Eligible” means that (a) Borrower’s Common Stock is eligible at DTC for full services pursuant
to DTC’s operational arrangements, including without limitation transfer through DTC’s DWAC system; (b) Borrower has
been approved (without revocation) by DTC’s underwriting department; (c) Borrower’s transfer agent is approved as
an agent in the DTC/FAST Program; (d) the Conversion Shares are otherwise eligible for delivery via DWAC other than due to the
actions or status of Lender; and (e) Borrower’s transfer agent does not have a policy prohibiting or limiting delivery of
the Conversion Shares via DWAC.

 

    	Attachment 1 to Secured Convertible Promissory Note, Page 1

     

    

 

A12.
“Fundamental Transaction” means that (a) (i) Borrower shall, directly or indirectly, in one or more related
transactions, consolidate or merge with or into (whether or not Borrower or any of its subsidiaries is the surviving corporation)
any other person or entity, or (ii) Borrower shall, directly or indirectly, in one or more related transactions, sell, lease,
license, assign, transfer, convey or otherwise dispose of all or substantially all of its respective properties or assets to any
other person or entity, or (iii) Borrower shall, directly or indirectly, in one or more related transactions, allow any other
person or entity to make a purchase, tender or exchange offer that is accepted by the holders of more than 50% of the outstanding
shares of voting stock of Borrower (not including any shares of voting stock of Borrower held by the person or persons making
or party to, or associated or affiliated with the persons or entities making or party to, such purchase, tender or exchange offer),
or (iv) Borrower shall, directly or indirectly, in one or more related transactions, consummate a stock or share purchase agreement
or other business combination (including, without limitation, a reorganization, recapitalization, spin-off or scheme of arrangement)
with any other person or entity whereby such other person or entity acquires more than 50% of the outstanding shares of voting
stock of Borrower (not including any shares of voting stock of Borrower held by the other persons or entities making or party
to, or associated or affiliated with the other persons or entities making or party to, such stock or share purchase agreement
or other business combination), or (v) Borrower shall, directly or indirectly, in one or more related transactions, reorganize,
recapitalize or reclassify the Common Stock, other than an increase in the number of authorized shares of Borrower’s Common
Stock, or (b) any “person” or “group” (as these terms are used for purposes of Sections 13(d) and 14(d)
of the 1934 Act and the rules and regulations promulgated thereunder) is or shall become the “beneficial owner” (as
defined in Rule 13d-3 under the 1934 Act), directly or indirectly, of 50% of the aggregate ordinary voting power represented by
issued and outstanding voting stock of Borrower.

 

A13.
“Major Default” means any Event of Default occurring under Sections 4.1(a), 4.1(c), 4.1(l), or 4.1(q) of this
Note.

 

A14.
“Mandatory Default Amount” means the Outstanding Balance following the application of the Default Effect.

 

A15.
“Market Capitalization” means a number equal to (a) the average VWAP of the Common Stock for the immediately
preceding fifteen (15) Trading Days, multiplied by (b) the aggregate number of outstanding shares of Common Stock as reported
on Borrower’s most recently filed Form 10-Q or Form 10-K.

 

A16.
“Market Price” means the Conversion Factor multiplied by the lowest daily VWAP during the ten (10) Trading
Days immediately preceding the applicable measurement date.

 

A17.
“Minor Default” means any Event of Default that is not a Major Default or an Unapproved Variable Security Issuance
Default.

 

A18.
“OID” means an original issue discount.

 

A19.
“Other Agreements” means, collectively, (a) all existing and future agreements and instruments between, among
or by Borrower (or an affiliate), on the one hand, and Lender (or an affiliate), on the other hand, and (b) any financing agreement
or a material agreement that affects Borrower’s ongoing business operations.

 

A20.
“Outstanding Balance” means as of any date of determination, the Purchase Price, as reduced or increased, as
the case may be, pursuant to the terms hereof for payment, Conversion, offset, or otherwise, plus the OID, the Transaction Expense
Amount, accrued but unpaid interest, collection and enforcements costs (including attorneys’ fees) incurred by Lender, transfer,
stamp, issuance and similar taxes and fees related to Conversions, and any other fees or charges (including without limitation
Conversion Delay Late Fees) incurred under this Note.

 

A21.
“Purchase Price Date” means the date the Purchase Price is delivered by Lender to Borrower.

 

A22.
“Trading Day” means any day on which the New York Stock Exchange (or such other principal market for the Common
Stock) is open for trading.

 

A23.
“Unapproved Variable Security Issuance” means a Variable Security Issuance for which Borrower did not receive
Lender’s written consent prior to the applicable issuance.

 

A24.
“Unapproved Variable Security Issuance Default” means an Event of Default occurring under Section 4.1(r) of
this Note.

 

A25.
“VWAP” means the volume weighted average price of the Common stock on the principal market for a particular
Trading Day or set of Trading Days, as the case may be, as reported by Bloomberg.

 

[Remainder of page
intentionally left blank]

 

    	Attachment 1 to Secured Convertible Promissory Note, Page 2

     

    

 

EXHIBIT
A

 

Iliad
Research and Trading, L.P.

303
East Wacker Drive, Suite 1040

Chicago,
Illinois 60601

 

	Hemispherx
    Biopharma, Inc.	Date:
    __________________
	Attn:
    Thomas Equels, CEO 	 
	2117
    SW Highway 484	 
	Ocala,
    Florida 34473	 

 

LENDER
CONVERSION NOTICE

 

The
above-captioned Lender hereby gives notice to Hemispherx Biopharma, Inc., a Delaware corporation (the “Borrower”),
pursuant to that certain Secured Convertible Promissory Note made by Borrower in favor of Lender on September 28, 2018 (the “Note”),
that Lender elects to convert the portion of the Note balance set forth below into fully paid and non-assessable shares of Common
Stock of Borrower as of the date of conversion specified below. Said conversion shall be based on the Lender Conversion Price
set forth below. In the event of a conflict between this Lender Conversion Notice and the Note, the Note shall govern, or, in
the alternative, at the election of Lender in its sole discretion, Lender may provide a new form of Lender Conversion Notice to
conform to the Note. Capitalized terms used in this notice without definition shall have the meanings given to them in the Note.

 

	A.	Date
    of Conversion: ____________
	B.	Lender
    Conversion #: ____________
	C.	Conversion
    Amount: ____________
	D.	Lender
    Conversion Price: _______________ 
	E.	Lender
    Conversion Shares: _______________ (C divided by D)
	F.	Remaining
    Outstanding Balance of Note: ____________* 

 

*
Subject to adjustments for corrections, defaults, interest and other adjustments permitted by the Transaction Documents (as defined
in the Purchase Agreement), the terms of which shall control in the event of any dispute between the terms of this Lender Conversion
Notice and such Transaction Documents.

 

Please
transfer the Lender Conversion Shares electronically (via DWAC) to the following account:

 

	Broker:
    	 	 	Address: 	 
	DTC#:
    	 	 	 	 
	Account
    #:	 	 	 	 
	Account
    Name:	 	 	 	 

 

To
the extent the Lender Conversion Shares are not able to be delivered to Lender electronically via the DWAC system, deliver all
such certificated shares to Lender via reputable overnight courier after receipt of this Lender Conversion Notice (by facsimile
transmission or otherwise) to:

 

	 	 	 
	 	 	 
	 	 	 

 

[Signature
Page Follows]

 

    	Exhibit A to Secured Convertible Promissory Note, Page 1

     

    

 

Sincerely,

 

Lender:

 

Iliad
Research and Trading, L.P.

 

	By: 	Iliad Management, LLC, its General Partner	 
	 	 	 	 	 
	 	By: 	Fife Trading, Inc., its Manager
	 	 	 	 	 
	 	 	By: 	 	 
	 	 	 	John
    M. Fife, President	 

 

    	Exhibit A to Secured Convertible Promissory Note, Page 2

     

    

 

EXHIBIT
B

 

Iliad
Research and Trading, L.P.

303
East Wacker Drive, Suite 1040

Chicago,
Illinois 60601

 

	Hemispherx
    Biopharma, Inc.	Date:
    __________________
	Attn:
    Thomas Equels, CEO	 
	2117
    SW Highway 484	 
	Ocala,
    Florida 34473	 

 

REDEMPTION
NOTICE

 

The
above-captioned Lender hereby gives notice to Hemispherx Biopharma, Inc., a Delaware corporation (the “Borrower”),
pursuant to that certain Secured Convertible Promissory Note made by Borrower in favor of Lender on September 28, 2018 (the “Note”),
that Lender elects to redeem a portion of the Note in Redemption Conversion Shares or in cash as set forth below. In the event
of a conflict between this Redemption Notice and the Note, the Note shall govern, or, in the alternative, at the election of Lender
in its sole discretion, Lender may provide a new form of Redemption Notice to conform to the Note. Capitalized terms used in this
notice without definition shall have the meanings given to them in the Note.

 

REDEMPTION
INFORMATION 

 

	A.	Redemption
    Date: ____________, 201_
	B.	Redemption
    Amount:____________
	C.	Portion
    of Redemption Amount to be Paid in Cash: ____________
	D.	Portion
    of Redemption Amount to be Converted into Common Stock: ____________ (B minus C)
	E.	Redemption
    Conversion Price: _______________ (lower of (i) Lender Conversion Price in effect and (ii) Market Price as of Redemption Date)
	F.	Redemption
    Conversion Shares: _______________ (D divided by E)
	G.	Remaining
    Outstanding Balance of Note: ____________ * 

 

*
Subject to adjustments for corrections, defaults, interest and other adjustments permitted by the Transaction Documents (as defined
in the Purchase Agreement), the terms of which shall control in the event of any dispute between the terms of this Redemption
Notice and such Transaction Documents.

 

Please
transfer the Redemption Conversion Shares, if applicable, electronically (via DWAC) to the following account:

 

	Broker:
    	 	 	Address: 	 
	DTC#:
    	 	 	 	 
	Account
    #:	 	 	 	 
	Account
    Name:	 	 	 	 

 

To
the extent the Redemption Conversion Shares are not able to be delivered to Lender electronically via the DWAC system, deliver
all such certificated shares to Lender via reputable overnight courier after receipt of this Redemption Notice (by facsimile transmission
or otherwise) to:

 

	 	 	 
	 	 	 
	 	 	 

 

    	Exhibit B to Secured Convertible Promissory Note, Page 1

     

    

 

Sincerely,

 

Lender:

 

Iliad
Research and Trading, L.P.

 

	By: 	Iliad Management, LLC, its General Partner	 
	 	 	 	 	 
	 	By: 	Fife Trading, Inc., its Manager
	 	 	 	 	 
	 	 	By: 	 	 
	 	 	 	John
    M. Fife, President	 

 

    	Exhibit B to Secured Convertible Promissory Note, Page 2

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