PLACEMENT AGENCY AGREEMENT

Exhibit 1.1

PLACEMENT AGENCY AGREEMENT

February 4, 2015                                        

Ladenburg Thalmann & Co. Inc.

4400 Biscayne Blvd

14th Floor

Miami, Florida 33137

Ladies and Gentlemen:

Introduction. Subject to the terms and conditions herein (this “Agreement”), Cleveland BioLabs, Inc., a Delaware corporation (the “Company”), hereby agrees to sell up to an aggregate of $4,218,079 of registered and unregistered securities of the Company, including, but not limited to, registered shares (the “Shares”) of the Company’s common stock, par value $0.005 per share (the “Common Stock”), registered Series B Prefunded Common Stock purchase warrants (the “Prefunded Warrants”) and shares of Common Stock underlying the Prefunded Warrants (the “Prefunded Warrant Shares”) and unregistered Series A Common Stock purchase warrants (the “Warrants”) and shares of Common Stock underlying the Warrants (the “Warrant Shares”) and shares of Series A Convertible Preferred Stock (the “Preferred Stock”) and the shares of Common Stock underlying the Preferred Stock (the “Conversion Shares” and together with the Shares, the Prefunded Warrants, the Prefunded Warrant Shares, the Warrants, the Warrant Shares, the Preferred Stock and the Conversion Shares, the “Securities”) directly to various investors (each, an “Investor” and, collectively, the “Investors”) through Ladenburg Thalmann & Co. Inc., as placement agent (“Ladenburg” or the “Placement Agent”). The Placement Agent may retain other brokers or dealers to act as sub-agents or selected-dealers on its behalf in connection with the Offering (as defined below).

The Company hereby confirms its agreement with the Placement Agent as follows:

Section 1. Agreement to Act as Placement Agent.

(a) On the basis of the representations, warranties and agreements of the Company herein contained, and subject to all the terms and conditions of this Agreement, the Placement Agent shall be the exclusive Placement Agent in connection with the offering and sale by the Company of the Securities from time to time pursuant to (i) the Company’s registration statement on Form S-3 (File No.333-192755) (the “Registration Statement”) and (ii) an exemption from the registration requirements of Section 5 of the Securities Act contained in Section 4(a)(2) thereof and/or Regulation D thereunder, with the terms of such offering (the “Offering”) to be subject to market conditions and negotiations between the Company and the prospective Investors. The Placement Agent will act on a reasonable best efforts basis and the Company agrees and acknowledges that there is no guarantee of the successful placement of the Securities, or any portion thereof, in the prospective Offering. Under no circumstances will the Placement Agent or any of its “Affiliates” (as defined below) be obligated to underwrite or purchase any of the Shares for its own account or otherwise provide any financing. The Placement Agent shall act solely as the Company’s agent and not as principal. The Placement Agent shall have no authority to bind the Company with respect to any prospective offer to purchase Shares and the Company shall have the sole right to accept offers to purchase Shares and may reject any such offer, in whole or in part. Subject to the terms and conditions hereof, payment of the purchase price for, and delivery of, the Securities shall be made at one or more closings (each a “Closing” and the date on which each Closing occurs, a “Closing Date”). As compensation for services rendered, on each Closing Date, the Company shall pay to the Placement Agent the fees and expenses set forth below:

(i) A cash fee equal to 8.0% of the gross proceeds received by the Company from the sale of the Securities at the closing of the Offering (the “Closing”).

(ii) Subject to compliance with FINRA Rule 5110(f)(2)(D), the Company also agrees to reimburse Ladenburg’s reasonable, out-of-pocket expenses. Such reimbursement shall be payable immediately upon (but only in the event of) a Closing of the Offering.

(b) The term of the Placement Agent’s exclusive engagement will be until the earlier of (i) December 31, 2015 or (ii) completion of the Offering (the “Exclusive Term”); provided, however, that a party hereto may terminate the engagement with respect to itself at any time upon 10 days written notice to the other parties. Notwithstanding anything to the contrary contained herein, the provisions concerning confidentiality, indemnification and contribution contained herein and the Company’s obligations contained in the indemnification provisions will survive any expiration or termination of this Agreement, and the Company’s obligation to pay fees actually earned and payable and to reimburse expenses actually incurred and reimbursable pursuant to Section 1 hereof and which are permitted to be reimbursed under FINRA Rule 5110(f)(2)(D), will survive any expiration or termination of this Agreement. Nothing in this Agreement shall be construed to limit the ability of the Placement Agent or its Affiliates to pursue, investigate, analyze, invest in, or engage in investment banking, financial advisory or any other business relationship with Persons (as defined below) other than the Company. As used herein (i) “Person” means an individual or corporation, partnership, trust, incorporated or unincorporated association, joint venture, limited liability company, joint stock company, government (or an agency or subdivision thereof) or other entity of any kind and (ii) “Affiliate” means any Person that, directly or indirectly through one or more intermediaries, controls or is controlled by or is under common control with a Person as such terms are used in and construed under Rule 405 under the Securities Act of 1933, as amended (the “Securities Act”).

Section 2. Representations, Warranties and Covenants of the Company. The Company hereby represents, warrants and covenants to the Placement Agent as of the date hereof, and as of each Closing Date, as follows

(a) Securities Law Filings. The Company has filed with the Securities and Exchange Commission (the “Commission”) the Registration Statement under the Securities Act, which was filed on December 10, 2013 and declared effective on January 10, 2014 for the registration of the Shares, the Prefunded Warrants and the Prefunded Warrant Shares. At the time of such filing, the Company met the requirements of Form S-3 under the Securities Act. Following the determination of pricing among the Company and the prospective Investors introduced to the Company by the Placement Agent, the Company will file with the Commission pursuant to Rule 424(b) under the Securities Act, and the rules and regulations (the “Rules and Regulations”) of the Commission promulgated thereunder, a prospectus supplement relating to the terms of the Offering and of the Securities and the plan of distribution thereof and will advise the Placement Agent of all further information (financial and other) with respect to the Company required to be set forth therein. Such registration statement, at any given time, including the exhibits thereto filed at such time, as amended at such time, is hereinafter called the “Registration Statement”; such prospectus in the form in which it appears in the Registration Statement is hereinafter called the “Base Prospectus”; and the amended or supplemented form of prospectus, in the form in which it will be filed with the Commission pursuant to Rule 424(b) (including the Base

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Prospectus as so amended or supplemented) is hereinafter called the “Prospectus Supplement.” The Registration Statement at the time it originally became effective is hereinafter called the “Original Registration Statement.” Any reference in this Agreement to the Registration Statement, the Original Registration Statement, the Base Prospectus or the Prospectus Supplement shall be deemed to refer to and include the documents incorporated by reference therein (the “Incorporated Documents”), if any, which were filed under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), at any given time, as the case may be; and any reference in this Agreement to the terms “amend,” “amendment” or “supplement” with respect to the Registration Statement, the Original Registration Statement, the Base Prospectus or the Prospectus Supplement shall be deemed to refer to and include the filing of any document under the Exchange Act after the date of this Agreement, or the issue date of the Base Prospectus or the Prospectus Supplement, as the case may be, deemed to be incorporated therein by reference. All references in this Agreement to financial statements and schedules and other information that is “contained,” “included,” “described,” “referenced,” “set forth” or “stated” in the Registration Statement, the Base Prospectus or the Prospectus Supplement (and all other references of like import) shall be deemed to mean and include all such financial statements and schedules and other information that is or is deemed to be incorporated by reference in the Registration Statement, the Base Prospectus or the Prospectus Supplement, as the case may be. The Company has not received any notice that the Commission has issued or intends to issue a stop order suspending the effectiveness of the Registration Statement or the use of the Base Prospectus or the Prospectus Supplement or intends to commence a proceeding for any such purpose.

(b) Assurances. The Original Registration Statement, as amended, (and any further documents to be filed with the Commission) contains all exhibits and schedules as required by the Securities Act. Each of the Registration Statement and any post-effective amendment thereto, at the time it became effective, complied in all material respects with the Securities Act and the Exchange Act and the applicable Rules and Regulations and did not and, as amended or supplemented, if applicable, will not, contain any 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 not misleading. The Base Prospectus, and the Prospectus Supplement, each as of its respective date, comply or will comply in all material respects with the Securities Act and the Exchange Act and the applicable Rules and Regulations. Each of the Base Prospectus and the Prospectus Supplement, as amended or supplemented, did not and will not contain as of the date thereof any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading. The Incorporated Documents, if any, when they were filed with the Commission, conformed in all material respects to the requirements of the Exchange Act and the applicable Rules and Regulations, and none of such documents, when they were filed with the Commission, contained any untrue statement of a material fact or omitted to state a material fact necessary to make the statements therein (with respect to Incorporated Documents incorporated by reference in the Base Prospectus or Prospectus Supplement), in light of the circumstances under which they were made not misleading; and any further documents so filed and incorporated by reference in the Base Prospectus or Prospectus Supplement, when such documents are filed with the Commission, will conform in all material respects to the requirements of the Exchange Act and the applicable Rules and Regulations, as applicable, and will not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in light of the circumstances under which they were made, not misleading. No post-effective amendment to the Registration Statement reflecting any facts or events arising after the date thereof which represent, individually or in the aggregate, a fundamental change in the information set forth therein is required to be filed with the Commission. There are no documents required to be filed with the Commission in connection with the transaction contemplated hereby that (x) have not

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been filed as required pursuant to the Securities Act or (y) will not be filed within the requisite time period. There are no contracts or other documents required to be described in the Base Prospectus, or Prospectus Supplement, or to be filed as exhibits or schedules to the Registration Statement, that have not been described or filed as required. The Company is eligible to use free writing prospectuses in connection with the Placement pursuant to Rules 164 and 433 under the Securities Act. Any free writing prospectus that the Company is required to file pursuant to Rule 433(d) under the Securities Act has been, or will be, filed with the Commission in accordance with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. Each free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act or that was prepared by or behalf of or used by the Company complies or will comply in all material respects with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. The Company will not, without the prior consent of the Placement Agent, prepare, use or refer to, any free writing prospectus, other than any free writing prospectus listed on Schedule B hereto.

(c) Offering Materials. The Company has delivered, or will as promptly as practicable deliver, to the Placement Agent complete conformed copies of the Registration Statement and of each consent and certificate of experts, as applicable, filed as a part thereof, and conformed copies of the Registration Statement (without exhibits), the Base Prospectus, and the Prospectus Supplement, as amended or supplemented, in such quantities and at such places as the Placement Agent reasonably requests. Neither the Company nor any of its directors and officers has distributed and none of them will distribute, prior to the Closing Date, any offering material in connection with the offering and sale of the Securities other than the Base Prospectus, the Prospectus Supplement, the Registration Statement, copies of the documents incorporated by reference therein and any other materials permitted by the Securities Act.

(d) Representations and Warranties Incorporated by Reference. Each of the representations and warranties (together with any related disclosure schedules thereto) made to the Purchasers in that certain Securities Purchase Agreement dated as of February 4, 2015, between the Company and each Investor, is hereby incorporated herein by reference (as though fully restated herein) and is hereby made to, and in favor of, the Placement Agent.

Section 3. Delivery and Payment. Each Closing shall occur at the offices of the Placement Agent (or at such other place as shall be agreed upon by the Placement Agent and the Company). Subject to the terms and conditions hereof, at each Closing payment of the purchase price for the Securities sold on such Closing Date shall be made by Federal Funds wire transfer, against delivery of such Securities, and such Securities shall be registered in such name or names and shall be in such denominations, as the Placement Agent may request at least one business day before the time of purchase (as defined below).

Deliveries of the documents with respect to the purchase of the Securities, if any, shall be made at the offices of Placement Agent. All actions taken at a Closing shall be deemed to have occurred simultaneously.

Section 4. Covenants and Agreements of the Company. The Company further covenants and agrees with the Placement Agent as follows:

(a) Registration Statement Matters. The Company will advise the Placement Agent promptly after it receives notice thereof of the time when any amendment to the Registration Statement has been filed or becomes effective or any supplement to any Prospectus Supplement or any amended Prospectus Supplement has been filed and will furnish the Placement Agent with copies thereof. The Company will file promptly all reports and any definitive proxy or

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information statements required to be filed by the Company with the Commission pursuant to Section 13(a), 14 or 15(d) of the Exchange Act subsequent to the date of any Prospectus Supplement and for so long as the delivery of a prospectus is required in connection with the Offering. The Company will advise the Placement Agent, promptly after it receives notice thereof (i) of any request by the Commission to amend the Registration Statement or to amend or supplement any Prospectus Supplement or for additional information, and (ii) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or any post-effective amendment thereto or any order directed at any Incorporated Document, if any, or any amendment or supplement thereto or any order preventing or suspending the use of the Base Prospectus or any Prospectus Supplement or any amendment or supplement thereto or any post-effective amendment to the Registration Statement, of the suspension of the qualification of the Securities for offering or sale in any jurisdiction, of the institution or threatened institution of any proceeding for any such purpose, or of any request by the Commission for the amending or supplementing of the Registration Statement or a Prospectus Supplement or for additional information. The Company shall use its best efforts to prevent the issuance of any such stop order or prevention or suspension of such use. If the Commission shall enter any such stop order or order or notice of prevention or suspension at any time, the Company will use its best efforts to obtain the lifting of such order at the earliest possible moment, or will file a new registration statement and use its best efforts to have such new registration statement declared effective as soon as practicable. Additionally, the Company agrees that it shall comply with the provisions of Rules 424(b), 430A, 430B and 430C, as applicable, under the Securities Act, including with respect to the timely filing of documents thereunder, and will use its reasonable efforts to confirm that any filings made by the Company under such Rule 424(b) are received in a timely manner by the Commission.

(b) Blue Sky Compliance. The Company will cooperate with the Placement Agent and the Investors in endeavoring to qualify the Securities for sale under the securities laws of such jurisdictions (United States and foreign) as the Placement Agent and the Investors may reasonably request and will make such applications, file such documents, and furnish such information as may be reasonably required for that purpose, provided the Company shall not be required to qualify as a foreign corporation or to file a general consent to service of process in any jurisdiction where it is not now so qualified or required to file such a consent, and provided further that the Company shall not be required to produce any new disclosure document other than a Prospectus Supplement. The Company will, from time to time, prepare and file such statements, reports and other documents as are or may be required to continue such qualifications in effect for so long a period as the Placement Agent may reasonably request for distribution of the Securities. The Company will advise the Placement Agent promptly of the suspension of the qualification or registration of (or any such exemption relating to) the Securities for offering, sale or trading in any jurisdiction or any initiation or threat of any proceeding for any such purpose, and in the event of the issuance of any order suspending such qualification, registration or exemption, the Company shall use its best efforts to obtain the withdrawal thereof at the earliest possible moment.

(c) Amendments and Supplements to a Prospectus Supplement and Other Matters. The Company will comply with the Securities Act and the Exchange Act, and the rules and regulations of the Commission thereunder, so as to permit the completion of the distribution of the Securities as contemplated in this Agreement, the Incorporated Documents and any Prospectus Supplement. If during the period in which a prospectus is required by law to be delivered in connection with the distribution of Securities contemplated by the Incorporated Documents or any Prospectus Supplement (the “Prospectus Delivery Period”), any event shall occur as a result of which, in the judgment of the Company or in the opinion of the Placement

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Agent, it becomes necessary to amend or supplement the Incorporated Documents or any Prospectus Supplement in order to make the statements therein, in the light of the circumstances under which they were made, as the case may be, not misleading, or if it is necessary at any time to amend or supplement the Incorporated Documents or any Prospectus Supplement or to file under the Exchange Act any Incorporated Document to comply with any law, the Company will promptly prepare and file with the Commission, and furnish at its own expense to the Placement Agent and to dealers, an appropriate amendment to the Registration Statement or supplement to the Registration Statement, the Incorporated Documents or any Prospectus Supplement that is necessary in order to make the statements in the Incorporated Documents and any Prospectus Supplement as so amended or supplemented, in the light of the circumstances under which they were made, as the case may be, not misleading, or so that the Registration Statement, the Incorporated Documents or any Prospectus Supplement, as so amended or supplemented, will comply with law. Before amending the Registration Statement or supplementing the Incorporated Documents or any Prospectus Supplement in connection with the Offering, the Company will furnish the Placement Agent with a copy of such proposed amendment or supplement and will not file any such amendment or supplement to which the Placement Agent reasonably objects.

(d) Copies of any Amendments and Supplements to a Prospectus Supplement. The Company will furnish the Placement Agent, without charge, during the period beginning on the date hereof and ending on the later of the last Closing Date of the Offering, as many copies of the Incorporated Documents and any Prospectus Supplement and any amendments and supplements thereto (including any Incorporated Documents, if any) as the Placement Agent may reasonably request.

(e) Free Writing Prospectus. Except as listed on Schedule B hereto, the Company covenants that it will not, unless it obtains the prior written consent of the Placement Agent, make any offer relating to the Securities that would constitute a Company Free Writing Prospectus or that would otherwise constitute a “free writing prospectus” (as defined in Rule 405 of the Securities Act) required to be filed by the Company with the Commission or retained by the Company under Rule 433 of the Securities Act. In the event that the Placement Agent expressly consents in writing to any such free writing prospectus (a “Permitted Free Writing Prospectus”), the Company covenants that it shall (i) treat each Permitted Free Writing Prospectus as a Company Free Writing Prospectus, and (ii) comply with the requirements of Rule 164 and 433 of the Securities Act applicable to such Permitted Free Writing Prospectus, including in respect of timely filing with the Commission, legending and record keeping.

(f) Transfer Agent. The Company will maintain, at its expense, a registrar and transfer agent for the Common Stock.

(g) Earnings Statement. As soon as practicable and in accordance with applicable requirements under the Securities Act, but in any event not later than 18 months after the last Closing Date, the Company will make generally available to its security holders and to the Placement Agent an earnings statement, covering a period of at least 12 consecutive months beginning after the last Closing Date, that satisfies the provisions of Section 11(a) and Rule 158 under the Securities Act.

(h) Periodic Reporting Obligations. During the Prospectus Delivery Period, the Company will duly file, on a timely basis, with the Commission and the Trading Market all reports and documents required to be filed under the Exchange Act within the time periods and in the manner required by the Exchange Act.

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(i) Additional Documents. The Company will enter into any subscription, purchase or other customary agreements as the Placement Agent or the Investors deem necessary or appropriate to consummate the Offering, all of which will be in form and substance reasonably acceptable to the Placement Agent and the Investors. The Company agrees that the Placement Agent may rely upon, and each is a third party beneficiary of, the representations and warranties, and applicable covenants, set forth in any such purchase, subscription or other agreement with Investors in the Offering.

(j) No Manipulation of Price. The Company will not take, directly or indirectly, any action designed to cause or result in, or that has constituted or might reasonably be expected to constitute, the stabilization or manipulation of the price of any securities of the Company.

(k) Acknowledgment. The Company acknowledges that any advice given by the Placement Agent to the Company is solely for the benefit and use of the Board of Directors of the Company and may not be used, reproduced, disseminated, quoted or referred to, without the Placement Agent’s prior written consent.

Section 5. Conditions of the Obligations of the Placement Agent. The obligations of the Placement Agent hereunder shall be subject to the accuracy of the representations and warranties on the part of the Company set forth in Section 2 hereof, in each case as of the date hereof and as of each Closing Date as though then made, to the timely performance by each of the Company of its covenants and other obligations hereunder on and as of such dates, and to each of the following additional conditions:

(a) Compliance with Registration Requirements; No Stop Order; No Objection from the FINRA. Each Prospectus Supplement (in accordance with Rule 424(b)) and “free writing prospectus” (as defined in Rule 405 of the Securities Act), if any, shall have been duly filed with the Commission, as appropriate; no stop order suspending the effectiveness of the Registration Statement or any part thereof shall have been issued and no proceeding for that purpose shall have been initiated or threatened by the Commission; no order preventing or suspending the use of any Prospectus Supplement shall have been issued and no proceeding for that purpose shall have been initiated or threatened by the Commission; no order having the effect of ceasing or suspending the distribution of the Securities or any other securities of the Company shall have been issued by any securities commission, securities regulatory authority or stock exchange and no proceedings for that purpose shall have been instituted or shall be pending or, to the knowledge of the Company, contemplated by any securities commission, securities regulatory authority or stock exchange; all requests for additional information on the part of the Commission shall have been complied with; and the FINRA shall have raised no objection to the fairness and reasonableness of the placement terms and arrangements.

(b) Corporate Proceedings. All corporate proceedings and other legal matters in connection with this Agreement, the Registration Statement and each Prospectus Supplement, and the registration, sale and delivery of the Securities, shall have been completed or resolved in a manner reasonably satisfactory to the Placement Agent’s counsel, and such counsel shall have been furnished with such papers and information as it may reasonably have requested to enable such counsel to pass upon the matters referred to in this Section 5.

(c) No Material Adverse Change. Subsequent to the execution and delivery of this Agreement and prior to each Closing Date, in the Placement Agent’s sole judgment after consultation with the Company, there shall not have occurred any Material Adverse Change or Material Adverse Effect.

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(d) Opinion of Counsel for the Company. The Placement Agent shall have received on each Closing Date the favorable opinion of legal counsel to the Company, dated as of such Closing Date, including, without limitation, a negative assurance letter, addressed to the Placement Agent in form and substance satisfactory to the Placement Agent.

(e) Opinion of Intellectual Property Counsel for the Company. The Placement Agent shall have received on each Closing Date the favorable opinion of intellectual property counsel to the Company, dated as of such Closing Date, including, without limitation, a negative assurance letter, addressed to the Placement Agent in form and substance satisfactory to the Placement Agent.

(f) Opinion of Counsel for the Placement Agent. The Placement Agent shall have received on each Closing Date the favorable opinion of legal counsel to the Placement Agent, dated as of such Closing Date, including, without limitation, a negative assurance letter, addressed to the Placement Agent.

(g) Officers’ Certificate. The Placement Agent shall have received on each Closing Date a certificate of the Company, dated as of such Closing Date, signed by the Chief Executive Officer and Chief Financial Officer of the Company, to the effect that, and the Placement Agent shall be satisfied that, the signers of such certificate have reviewed the Registration Statement, the Incorporated Documents, any Prospectus Supplement, any Permitted Free Writing Prospectus and this Agreement and to the further effect that:

(i) The representations and warranties of the Company in this Agreement are true and correct, as if made on and as of such Closing Date, and the Company has complied with all the agreements and satisfied all the conditions on its part to be performed or satisfied at or prior to such Closing Date;

(ii) No stop order suspending the effectiveness of the Registration Statement or the use of the Base Prospectus or any Prospectus Supplement has been issued and no proceedings for that purpose have been instituted or are pending or, to the Company’s knowledge, threatened under the Securities Act; no order having the effect of ceasing or suspending the distribution of the Securities or any other securities of the Company has been issued by any securities commission, securities regulatory authority or stock exchange in the United States and no proceedings for that purpose have been instituted or are pending or, to the knowledge of the Company, contemplated by any securities commission, securities regulatory authority or stock exchange in the United States;

(iii) When the Registration Statement became effective, at the time of sale, and at all times subsequent thereto up to the delivery of such certificate, the Registration Statement and the Incorporated Documents, if any, when such documents became effective or were filed with the Commission, contained all material information required to be included therein by the Securities Act and the Exchange Act and the applicable rules and regulations of the Commission thereunder, as the case may be, and in all material respects conformed to the requirements of the Securities Act and the Exchange Act and the applicable rules and regulations of the Commission thereunder, as the case may be, and the Registration Statement and the Incorporated Documents, if any, did not and do not include any 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 the light of the circumstances under which they were made, not misleading (provided, however, that the preceding representations and warranties contained in this paragraph (iii) shall not

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apply to any statements or omissions made in reliance upon and in conformity with information furnished in writing to the Company by the Placement Agent expressly for use therein) and, since the effective date of the Registration Statement, there has occurred no event required by the Securities Act and the rules and regulations of the Commission thereunder to be set forth in the Incorporated Documents which has not been so set forth; and

(iv) Subsequent to the respective dates as of which information is given in the Registration Statement, the Incorporated Documents and any Prospectus Supplement, there has not been: (a) any Material Adverse Change; (b) any transaction that is material to the Company and the Subsidiaries taken as a whole, except transactions entered into in the ordinary course of business; (c) any obligation, direct or contingent, that is material to the Company and the Subsidiaries taken as a whole, incurred by the Company or any Subsidiary, except obligations incurred in the ordinary course of business; (d) any material change in the capital stock (except changes thereto resulting from the exercise of outstanding stock options or warrants) or outstanding indebtedness of the Company or any Subsidiary; (e) any dividend or distribution of any kind declared, paid or made on the capital stock of the Company; or (f) any loss or damage (whether or not insured) to the property of the Company or any Subsidiary which has been sustained or will have been sustained which has a Material Adverse Effect.

(h) Escrow Agreement. The Company and the Placement Agent shall have entered into an escrow agreement with a commercial bank or trust company reasonably satisfactory to both parties pursuant to which the Investors shall deposit their subscription funds in an escrow account and the Company and the Placement Agent shall jointly authorize the disbursement of the funds from the escrow account. The Company shall pay the reasonable fees of the escrow agent.

(i) Stock Exchange Listing. The Common Stock shall be registered under the Exchange Act and shall be listed on the principal Trading Market, and the Company shall not have taken any action designed to terminate, or likely to have the effect of terminating, the registration of the Common Stock under the Exchange Act or delisting or suspending from trading the Common Stock from the principal Trading Market, nor shall the Company have received any information suggesting that the Commission or the principal Trading Market is contemplating terminating such registration or listing.

(j) Additional Documents. On or before each Closing Date, the Placement Agent and counsel for the Placement Agent shall have received such information and documents as they may reasonably require for the purposes of enabling them to pass upon the issuance and sale of the Securities as contemplated herein, or in order to evidence the accuracy of any of the representations and warranties, or the satisfaction of any of the conditions or agreements, herein contained.

If any condition specified in this Section 5 is not satisfied when and as required to be satisfied, this Agreement may be terminated by the Placement Agent by notice to the Company at any time on or prior to a Closing Date, which termination shall be without liability on the part of any party to any other party, except that Section 6 (Payment of Expenses), Section 7 (Indemnification and Contribution) and Section 8 (Representations and Indemnities to Survive Delivery) shall at all times be effective and shall survive such termination.

Section 6. Payment of Expenses. The Company agrees to pay all costs, fees and expenses incurred by the Company in connection with the performance of its obligations hereunder and in connection with

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the transactions contemplated hereby, including, without limitation: (i) all expenses incident to the issuance, delivery and qualification of the Securities (including all printing and engraving costs); (ii) all fees and expenses of the registrar and transfer agent of the Common Stock; (iii) all necessary issue, transfer and other stamp taxes in connection with the issuance and sale of the Securities; (iv) all fees and expenses of the Company’s counsel, independent public or certified public accountants and other advisors; (v) all costs and expenses incurred in connection with the preparation, printing, filing, shipping and distribution of the Registration Statement (including financial statements, exhibits, schedules, consents and certificates of experts), the Base Prospectus and each Prospectus Supplement, and all amendments and supplements thereto, and this Agreement; (vi) all filing fees, reasonable attorneys’ fees and expenses incurred by the Company or the Placement Agent in connection with qualifying or registering (or obtaining exemptions from the qualification or registration of) all or any part of the Securities for offer and sale under the state securities or blue sky laws or the securities laws of any other country, and, if requested by the Placement Agent, preparing and printing a “Blue Sky Survey,” an “International Blue Sky Survey” or other memorandum, and any supplements thereto, advising the Placement Agent of such qualifications, registrations and exemptions; (vii) if applicable, the filing fees incident to the review and approval by the FINRA of the Placement Agent’s participation in the offering and distribution of the Securities; (viii) the fees and expenses associated with including the Securities on the Trading Market; (ix) all costs and expenses incident to the travel and accommodation of the Company’s and the Placement Agent’s employees on the “roadshow,” if any; and (x) all other fees, costs and expenses referred to in Part II of the Registration Statement.

Section 7. Indemnification and Contribution. The Company agrees to indemnify the Placement Agent in accordance with the provisions of Schedule A hereto, which is incorporated by reference herein and made a part hereof.

Section 8. Representations and Indemnities to Survive Delivery. The respective indemnities, agreements, representations, warranties and other statements of the Company or any person controlling the Company, of its officers, and of the Placement Agent set forth in or made pursuant to this Agreement will remain in full force and effect, regardless of any investigation made by or on behalf of the Placement Agent, the Company, or any of its or their partners, officers or directors or any controlling person, as the case may be, and will survive delivery of and payment for the Securities to be sold in the proposed Offering and any termination of this Agreement. A successor to a Placement Agent, or to the Company, its directors or officers or any person controlling the Company, shall be entitled to the benefits of the indemnity, contribution and reimbursement agreements contained in this Agreement.

Section 9. Notices. All communications hereunder shall be in writing and shall be mailed, hand delivered or telecopied and confirmed to the parties hereto as follows:

If to the Placement Agent to the address set forth above, attn: General Counsel, Facsimile: 305 ###-###-####.

With a copy to:

Ellenoff Grossman & Schole LLP

1345 Avenue of the Americas

New York, New York 10105

Facsimile: 212 ###-###-####

Attention: Joseph Smith

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If to the Company:

Cleveland BioLabs, Inc.

73 High Street

Buffalo, NY 14203

Facsimile: 716 ###-###-####

Attention: Yakov Kogan Ph.D.

With a copy to:

Cooley LLP

500 Boylston Street

Boston, MA 02116

Facsimile: 617 ###-###-####

Attention: Marc Recht

Any party hereto may change the address for receipt of communications by giving written notice to the others.

Section 10. Successors. This Agreement will inure to the benefit of and be binding upon the parties hereto, and to the benefit of the employees, officers and directors and controlling persons referred to in Section 7 hereof, and to their respective successors, and personal representative, and no other person will have any right or obligation hereunder.

Section 11. Partial Unenforceability. The invalidity or unenforceability of any section, paragraph or provision of this Agreement shall not affect the validity or enforceability of any other section, paragraph or provision hereof. If any Section, paragraph or provision of this Agreement is for any reason determined to be invalid or unenforceable, there shall be deemed to be made such minor changes (and only such minor changes) as are necessary to make it valid and enforceable.

Section 12. Governing Law Provisions. This Agreement shall be deemed to have been made and delivered in New York City and both this engagement letter and the transactions contemplated hereby shall be governed as to validity, interpretation, construction, effect and in all other respects by the internal laws of the State of New York, without regard to the conflict of laws principles thereof. Each of the Placement Agent and the Company: (i) agrees that any legal suit, action or proceeding arising out of or relating to this engagement letter and/or the transactions contemplated hereby shall be instituted exclusively in New York Supreme Court, County of New York, or in the United States District Court for the Southern District of New York, (ii) waives any objection which it may have or hereafter to the venue of any such suit, action or proceeding, and (iii) irrevocably consents to the jurisdiction of the New York Supreme Court, County of New York, and the United States District Court for the Southern District of New York in any such suit, action or proceeding. Each of the Placement Agent and the Company further agrees to accept and acknowledge service of any and all process which may be served in any such suit, action or proceeding in the New York Supreme Court, County of New York, or in the United States District Court for the Southern District of New York and agrees that service of process upon the Company mailed by certified mail to the Company’s address shall be deemed in every respect effective service of process upon the Company, in any such suit, action or proceeding, and service of process upon the Placement Agent mailed by certified mail to the Placement Agent’s address shall be deemed in every respect effective service process upon the Placement Agent, in any such suit, action or proceeding. Notwithstanding any provision of this engagement letter to the contrary, the Company agrees that neither the Placement Agent nor its affiliates, and the respective officers, directors, employees, agents and

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representatives of the Placement Agent, its affiliates and each other person, if any, controlling the Placement Agent or any of its affiliates, shall have any liability (whether direct or indirect, in contract or tort or otherwise) to the Company for or in connection with the engagement and transaction described herein except for any such liability for losses, claims, damages or liabilities incurred by us that are finally judicially determined to have resulted from the bad faith or gross negligence of such individuals or entities. If either party shall commence an action or proceeding to enforce any provision of this Agreement, then the prevailing party in such action or proceeding shall be reimbursed by the other party for its reasonable attorney’s fees and other costs and expenses incurred with the investigation, preparation and prosecution of such action or proceeding.

Section 13. General Provisions.

(a) This Agreement constitutes the entire agreement of the parties to this Agreement and supersedes all prior written or oral and all contemporaneous oral agreements, understandings and negotiations with respect to the subject matter hereof. This Agreement may be executed in two or more counterparts, each one of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument. This Agreement may not be amended or modified unless in writing by all of the parties hereto, and no condition herein (express or implied) may be waived unless waived in writing by each party whom the condition is meant to benefit. Section headings herein are for the convenience of the parties only and shall not affect the construction or interpretation of this Agreement. Notwithstanding anything herein to the contrary, the Investment Banking Agreement, dated November 4, 2014, as amended, by and between the parties hereto shall continue to be effective and the terms therein, including but not limited to Sections 4(b) and 5 with respect to any future offerings, shall continue to survive and be enforceable by the Placement Agent, in accordance with its terms.

(b) The Company acknowledges that in connection with the offering of the Securities: (i) the Placement Agent has acted at arms length, are not agents of, and owe no fiduciary duties to the Company or any other person, (ii) the Placement Agent owes the Company only those duties and obligations set forth in this Agreement and (iii) the Placement Agent may have interests that differ from those of the Company. The Company waives to the full extent permitted by applicable law any claims it may have against the Placement Agent arising from an alleged breach of fiduciary duty in connection with the offering of the Securities

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If the foregoing is in accordance with your understanding of our agreement, please sign below whereupon this instrument, along with all counterparts hereof, shall become a binding agreement in accordance with its terms.

The foregoing Placement Agency Agreement is hereby confirmed and accepted as of the date first above written.

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SCHEDULE A – INDEMNIFICATION

The Company hereby agrees to indemnify and hold Ladenburg, its officers, directors, principals, employees, affiliates, and shareholders, and their successors and assigns, harmless from and against any and all loss, claim, damage, liability, deficiencies, actions, suits, proceedings, costs and legal expenses or expense whatsoever (including, but not limited to, reasonable legal fees and other expenses and reasonable disbursements incurred in connection with investigating, preparing to defend or defending any action, suit or proceeding, including any inquiry or investigation, commenced or threatened, or any claim whatsoever, or in appearing or preparing for appearance as witness in any proceeding, including any pretrial proceeding such as a deposition) (collectively, “Losses”) arising out of, based upon, or in any way related or attributed to, (i) any breach of a representation, warranty or covenant by the Company contained in this Agreement or (ii) any activities or services performed hereunder by Ladenburg, unless it is finally judicially determined in a court of competent jurisdiction that such Losses were the primary and direct result of the intentional misconduct or gross negligence of Ladenburg in performing the services hereunder.

If Ladenburg receives written notice of the commencement of any legal action, suit or proceeding with respect to which the Company is or may be obligated to provide indemnification pursuant to this Schedule A, Ladenburg shall, within thirty (30) days of the receipt of such written notice, give the Company written notice thereof (a “Claim Notice”). Failure to give such Claim Notice within such thirty (30) day period shall not constitute a waiver by Ladenburg of its right to indemnity hereunder with respect to such action, suit or proceeding. Upon receipt by the Company of a Claim Notice from Ladenburg with respect to any claim for indemnification which is based upon a claim made by a third party (“Third Party Claim”), the Company may assume the defense of the Third Party Claim with counsel of its own choosing, as described below. Ladenburg shall cooperate in the defense of the Third Party Claim and shall furnish such records, information and testimony and attend all such conferences, discovery proceedings, hearings, trial and appeals as may be reasonably required in connection therewith. Ladenburg shall have the right to employ its own counsel in any such action, which shall be at the Company’s expense if (i) the Company and Ladenburg shall have mutually agreed in writing to the retention of such counsel, (ii) the Company shall have failed in a timely manner to assume the defense and employ counsel or experts reasonably satisfactory to Ladenburg in such litigation or proceeding or (iii) the named parties to any such litigation or proceeding (including any impleaded parties) include the Company and Ladenburg and representation of the Company and Ladenburg by the same counsel or experts would, in the reasonable opinion of Ladenburg, be inappropriate due to actual or potential differing interests between the Company and Ladenburg. The Company shall not satisfy or settle any Third Party Claim for which indemnification has been sought and is available hereunder, without the prior written consent of Ladenburg, which consent shall not be delayed and which shall not be required if Ladenburg is granted a release in connection therewith. The indemnification provisions hereunder shall survive the termination or expiration of this Agreement.

The Company further agrees, upon demand by Ladenburg, to promptly reimburse Ladenburg for, or pay, any fees, expenses or disbursements as to which Ladenburg has been indemnified herein with such reimbursement to be made currently as any such fees, expenses or disbursements are incurred by Ladenburg. Notwithstanding the provisions of the aforementioned indemnification, any such reimbursement or payment by the Company of fees, expenses, or disbursements incurred by Ladenburg shall be repaid by Ladenburg in the event of any proceeding in which a final judgment (after all appeals or the expiration of time to appeal) is entered in a court of competent jurisdiction against Ladenburg based solely upon its gross negligence or intentional misconduct in the performance of its duties hereunder, and provided further, that the Company shall not be required to make reimbursement or payment for any settlement effected without the Company’s prior written consent (which consent shall not be unreasonably withheld or delayed).

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If for any reason the foregoing indemnification is unavailable or is insufficient to hold Ladenburg harmless, the Company agrees to contribute the amount paid or payable by Ladenburg in such proportion as to reflect not only the relative benefits received by the Company, on the one hand, and Ladenburg, on the other hand, but also the relative fault of the Company and Ladenburg as well as any relevant equitable considerations. In no event shall Ladenburg contribute in excess of the fees actually received by it pursuant to the terms of this Agreement.

For purposes of this Agreement, each officer, director, shareholder, and employee or affiliate of Ladenburg and each person, if any, who controls Ladenburg (or any affiliate) within the meaning of either Section 15 of the Securities Act of 1933, as amended, or Section 20 of the Securities Exchange Act of 1934, as amended, shall have the same rights as Ladenburg with respect to matters of indemnification by the Company hereunder.

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Schedule B

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