Exhibit 10.15

LEAK-OUT AGREEMENT

October ●, 2019

This agreement (the “Leak-Out Agreement”) is being delivered to you in connection with an understanding by and between iBio, Inc., a Delaware corporation (the “Company”), and the person or persons named on the signature pages hereto (collectively, the “Holder”).

Reference is hereby made to (a) the Underwriting Agreement, dated October ●, 2019, by and among the Company and A.G.P./Alliance Global Partners (“AGP”), as representative of the several underwriters, in connection with the follow-on underwritten public offering (the “Offering”) of the Company (the “UA”) pursuant to which the Holder and certain other purchasers acquired (i) shares of Common Stock of the Company (“Shares”), (ii) Series C Convertible Preferred Stock (the “Preferred”), whose terms are governed by a certain Certificate of Designation of Preferences, Rights and Limitations of Series C Convertible Preferred Stock, dated October ●, 2019 (the “CoD”), and (iii) warrants of the Company to purchase Shares, the “Firm Common Warrants,” and together with the Shares and Preferred, the “Securities”) and (b) the registration statement on Form S-1 (File No. 333-233504) (“Registration Statement”). Capitalized terms not defined herein shall have the meaning as set forth in the UA, unless otherwise set forth herein.

The Holder agrees solely with the Company that from the pricing date of the Offering that the UA is entered into by the Company and AGP (the “Effective Date”) and ending at 4:00 pm (New York City time) on _____, 2019¹ (such period, the “Restricted Period”), neither the Holder, nor any affiliate of such Holder which (x) had or has knowledge of the transactions contemplated by the UA, (y) has or shares discretion relating to such Holder’s investments or trading or information concerning such Holder’s investments, including in respect of the Securities, or (z) is subject to such Holder’s review or input concerning such affiliate’s investments or trading (together, the “Holder’s Trading Affiliates”), collectively, shall sell, dispose or otherwise transfer, directly or indirectly, (including, without limitation, any sales, short sales, swaps or any derivative transactions that would be equivalent to any sales or short positions) on any Trading Day during the Restricted Period (any such date, a “Date of Determination”), shares of Common Stock of the Company, or shares of common stock of the Company underlying any Convertible Securities or Options (each as defined in the CoD), held by the Holder on the date hereof, as well as the Shares and the shares of Common Stock of the Company issuable upon exercise of the Preferred and Firm Common Warrants (collectively, the “Restricted Securities”), in an amount representing more than [ ]%² of the average daily volume of Common Stock as reported by Bloomberg, LP on each applicable Date of Determination (“Leak-Out Percentage”); provided that the Leak-Out Percentage shall not be in effect on any day on which the price of the Common Stock trades by 200% over the Public Offering Price; provided, further, that the foregoing restriction shall not apply to any actual “long” (as defined in Regulation SHO of the Securities Exchange Act of 1934, as amended) sales by the Holder or any of the Holder’s Trading Affiliates at a price greater than $0.● (in each case, as adjusted for stock splits, stock dividends, stock combinations, recapitalizations or other similar events occurring after the date hereof).

Notwithstanding anything herein to the contrary, during the Restricted Period, the Holder may, directly or indirectly, sell or transfer all, or any part, of any Restricted Securities to any Person (an “Assignee”) in a transaction which does not need to be reported on the consolidated tape on the Principal Market, without complying with (or otherwise limited by) the restrictions set forth in this Leak-Out Agreement; provided, that as a condition to any such sale or transfer an authorized signatory of the Company and such Assignee duly execute and deliver a leak-out agreement in the form of this Leak-Out Agreement (an “Assignee Agreement”, and each such transfer a “Permitted Transfer”) and, subsequent to a Permitted Transfer, sales of the Holder and the Holder’s Trading Affiliates and all Assignees (other than any such sales that constitute Permitted Transfers) shall be aggregated for all purposes of this Leak-Out Agreement and all Assignee Agreements.

Any notices, consents, waivers or other communications required or permitted to be given under the terms of this Leak-Out Agreement must be in writing and shall be given in accordance with the terms of the UA.

This Leak-Out Agreement constitutes the entire agreement among the parties hereto with respect to the subject matter hereof and supersedes all prior negotiations, letters and understandings relating to the subject matter hereof and are fully binding on the parties hereto.

This Leak-Out Agreement may be executed simultaneously in any number of counterparts. Each counterpart shall be deemed to be an original, and all such counterparts shall constitute one and the same instrument. This Leak-Out Agreement may be executed and accepted by facsimile or PDF signature and any such signature shall be of the same force and effect as an original signature.

The terms of this Leak-Out Agreement shall be binding upon and shall inure to the benefit of each of the parties hereto and their respective successors and assigns.

This Leak-Out Agreement may not be amended or modified except in writing signed by each of the parties hereto.

All questions concerning the construction, validity, enforcement and interpretation of this Leak-Out Agreement shall be governed by the applicable provisions of the UA.

Each party hereto acknowledges that, in view of the uniqueness of the transactions contemplated by this Leak-Out Agreement, the other party or parties hereto may not have an adequate remedy at law for money damages in the event that this Leak-Out Agreement has not been performed in accordance with its terms, and therefore agrees that such other party or parties shall be entitled to seek specific enforcement of the terms hereof in addition to any other remedy it may seek, at law or in equity.

The Holder acknowledges that it is not a party to the UA and AGP has acted as representative of the several underwriters and all of the purchasers in the Offering. The obligations of the Holder under this Leak-Out Agreement are several and not joint with the obligations of any other holder of any of the Securities issued under the UA (each, an “Other Holder”) or any other holder of any of the Securities issued under the Registration Statement that is not a signatory to the UA (each, a “Prospectus Purchaser Other Holder”) under any other agreement, and the Holder shall not be responsible in any way for the performance of the obligations of any Other Holder or any Prospectus Purchaser Other Holder under any such other agreement. Nothing contained in this Leak-Out Agreement, and no action taken by the Holder pursuant hereto, shall be deemed to constitute the Holder and Other Holders or any Prospectus Purchaser Other Holder as a partnership, an association, a joint venture or any other kind of entity, or create a presumption that the Holder and the Other Holders or any Prospectus Purchaser Other Holder are in any way acting in concert or as a group with respect to such obligations or the transactions contemplated by this Leak-Out Agreement and the Company acknowledges that the Holder and the Other Holders or any Prospectus Purchaser Other Holder are not acting in concert or as a group with respect to such obligations or the transactions contemplated by this Leak-Out Agreement or any other agreement. The Company and the Holder confirm that the Holder has independently participated in the negotiation of the transactions contemplated hereby with the advice of its own counsel and advisors. The Holder shall be entitled to independently protect and enforce its rights, including, without limitation, the rights arising out of this Leak-Out Agreement, and it shall not be necessary for any Other Holder or any Prospectus Purchaser Other Holder to be joined as an additional party in any proceeding for such purpose.

The Company hereby represents and warrants as of the date hereof and covenants and agrees from and after the date hereof that none of the terms offered to any Other Holder or any Prospectus Purchaser Other Holder that purchases $250,000 or more of the Securities in the Offering with respect to any restrictions on the sale of Securities substantially in the form of this Leak-Out Agreement (or any amendment, modification, waiver or release thereof) (each a “Settlement Document”), is or will be more favorable to such Other Holder than those of the Holder and this Leak-Out Agreement. If, and whenever on or after the date hereof, the Company enters into a Settlement Document with terms that are materially different from this Leak-Out Agreement, then (i) the Company shall provide notice thereof to the Holder promptly following the occurrence thereof and (ii) the terms and conditions of this Leak-Out Agreement shall be, without any further action by the Holder or the Company, automatically amended and modified in an economically and legally equivalent manner such that the Holder shall receive the benefit of the more favorable terms and/or conditions (as the case may be) set forth in such Settlement Document, provided that upon written notice to the Company at any time the Holder may elect not to accept the benefit of any such amended or modified term or condition, in which event the term or condition contained in this Leak-Out Agreement shall apply to the Holder as it was in effect immediately prior to such amendment or modification as if such amendment or modification never occurred with respect to the Holder. The provisions of this paragraph shall apply similarly and equally to each Settlement Document.

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The parties hereto have executed this Leak-Out Agreement as of the date first set forth above.