Organization and Basis of Presentation	9 Months Ended
Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	Organization and Basis of Presentation Eleven Biotherapeutics, Inc. (the “Company”), a Delaware corporation formed on February 25, 2008, is a biologics oncology company focused on designing, engineering and developing targeted protein therapeutics ("TPTs"). The Company's TPTs are single-protein therapeutics composed of targeting moieties genetically fused via linker domains to cytotoxic protein payloads that are produced through the Company's proprietary one-step manufacturing process. The Company targets tumor cell surface antigens that allow for rapid internalization into the targeted cancer cell and have limited expression on normal cells. The Company has designed its TPTs to overcome the fundamental efficacy and safety challenges inherent in existing antibody drug conjugates ("ADCs"), where a payload is chemically attached to a targeting antibody. On September 20, 2016, the Company entered into a Share Purchase Agreement with Viventia Bio Inc., a corporation incorporated under the laws of the Province of Ontario, Canada (“Viventia”), the shareholders of Viventia named therein (the “Selling Shareholders”) and, solely in its capacity as seller representative, Clairmark Investments Ltd., a corporation incorporated under the laws of the Province of Ontario, Canada (“Clairmark”) (the “Share Purchase Agreement”), pursuant to which the Company agreed to and simultaneously completed the acquisition of all of the outstanding capital stock of Viventia from the Selling Shareholders (the “Acquisition”). In connection with the closing of the Acquisition, the Company issued 4,013,431 shares of its common stock to the Selling Shareholders, which represented approximately 19.9% of the voting power of the Company as of immediately prior to the issuance of such shares of the Company's common stock. In addition, under the Share Purchase Agreement, the Company will be obligated to pay to the Selling Shareholders certain post closing contingent cash payments upon the achievement of specified milestones and based upon net sales, in each case subject to the terms and conditions set forth in the Share Purchase Agreement, including: (i) a one-time milestone payment of $12.5 million payable upon the first sale of Vicinium^TM or any variant or derivative thereof, other than Proxinium^TM (the “Purchased Product”), in the United States; (ii) a one-time milestone payment of $7.0 million payable upon the first sale of the Purchased Product in any one of certain specified European countries; (iii) a one-time milestone payment of $3.0 million payable upon the first sale of the Purchased Product in Japan; and (iv) and quarterly earn-out payments equal to two percent (2%) of net sales of the Purchased Product during specified earn-out periods. Such earn-out payments are payable with respect to net sales in a country beginning on the date of the first sale in such country and ending on the earlier of (i) December 31, 2033 and (ii) fifteen years after the date of such sale, subject to early termination in certain circumstances if a biosimilar product is on the market in the applicable country. Under the Share Purchase Agreement, the Company, its affiliates, licensees and subcontractors are required to use commercially reasonable efforts, for first seven years following the closing of the Acquisition, to achieve marketing authorizations throughout the world and, during the applicable earn-out period, to commercialize the Purchased Product in the United States, France, Germany, Italy, Spain, United Kingdom, Japan, China and Canada. Certain of these payments are payable to individuals or affiliates of individuals that became employees or members of the Board of Directors of the Company (the "Board"). Each of the Company, Viventia and the Selling Shareholders has agreed to customary representations, warranties and covenants in the Share Purchase Agreement. The Share Purchase Agreement also includes indemnification obligations in favor of the Company from the Selling Shareholders, including for breaches of representations, warranties, covenants and agreements made by Viventia and the Selling Shareholders in the Share Purchase Agreement. In connection with the closing of the Acquisition, the Company deposited 401,343 shares of its common stock (representing approximately 10% of the Company's common stock portion of the aggregate closing consideration owed to the Selling Shareholders pursuant to the Share Purchase Agreement) into an escrow fund for the purposes of securing the indemnification obligations of the Selling Shareholders to the Company for any and all losses for which the Company is entitled to indemnification pursuant to the Share Purchase Agreement. The Share Purchase Agreement also includes indemnification obligations in favor of the Selling Shareholders from the Company, including for breaches of representations, warranties, covenants and agreements made by the Company in the Share Purchase Agreement. As a result of the Acquisition, Viventia became a wholly owned subsidiary of the Company (See Note 3). License Transaction On June 10, 2016, the Company entered into a License Agreement (the “License Agreement”) with F. Hoffmann-La Roche Ltd and Hoffmann-La Roche Inc. (collectively, “Roche”), which became effective on August 16, 2016. Under the License Agreement, the Company granted Roche an exclusive, worldwide license, including the right to sublicense, to its patent rights and know-how related to the Company’s monoclonal antibody EBI-031 or any other IL-6 antagonist anti-IL-6 monoclonal antibody, to make, have made, use, have used, register, have registered, sell, have sold, offer for sale, import and export any product containing such an antibody or any companion diagnostic used to predict or monitor response to treatment with such a product (collectively, the “Licensed Intellectual Property”). Under the License Agreement, Roche is required to continue developing EBI-031 and any other product made from the Licensed Intellectual Property that contains an IL-6 antagonist anti-IL-6 monoclonal antibody (a “Licensed Product”) at its cost. Financial Terms The Company received an upfront license fee of $7.5 million from Roche and Roche agreed to pay up to an additional $262.5 million upon the achievement of specified regulatory, development and commercial milestones with respect to up to two unrelated indications. Specifically, an aggregate amount of up to $197.5 million is payable to the Company for the achievement of specified milestones with respect to the first indication: $72.5 million in development milestones, $50.0 million in regulatory milestones and $75.0 million in commercialization milestones. Additional amounts of up to $65.0 million are payable upon the achievement of specified development and regulatory milestones in a second indication. The first development milestone payment for the first indication was paid in the amount of $22.5 million as a result of the IND application for EBI-031 becoming effective on or before September 15, 2016. In addition, the Company is entitled to receive royalty payments in accordance with a tiered royalty rate scale, with rates ranging from 7.5% to 15% for net sales of potential future products containing EBI-031 and up to 50% of these rates for net sales of potential future products containing other IL-6 compounds, with each of the royalties subject to reduction under certain circumstances and to the buy-out options of Roche further described below. Buy-Out Options The License Agreement provides for two “option periods” during which Roche may elect to make a one-time payment to the Company and, in turn, terminate its diligence, milestone and royalty payment obligations under the License Agreement. Specifically, (i) Roche may exercise a buy-out option following the first dosing (“Initiation”) in the first Phase II study for a Licensed Product until the day before Initiation of the first Phase III study for a Licensed Product, in which case Roche is required to pay the Company $135 million within 30 days after Roche's exercise of such buy-out option and receipt of an invoice from the Company, or (ii) Roche may exercise a buy-out option following the day after Initiation of the first Phase III study for a Licensed Product until the day before the acceptance for review by the FDA or other regulatory authority of a biologics license application (“BLA”) or similar application for marketing approval for a Licensed Product in either the United States or in the European Union, in which case Roche is required to pay the Company, within 30 days after Roche’s exercise of such buy-out option and receipt of an invoice from the Company, $265 million, which amount would be reduced to $220 million if none of the Company’s patent rights containing a composition of matter claim covering any compound or Licensed Product has issued in the European Union. Termination The Company or Roche may each terminate the License Agreement if the other party breaches any of its material obligations under the License Agreement and does not cure such breach within a specified cure period. Roche may terminate the License Agreement following effectiveness by providing advance written notice to the Company or by providing written notice if the Company is debarred, disqualified, suspended, excluded, or otherwise declared ineligible from certain federal or state agencies or programs. The Company may terminate the License Agreement if, prior to the first filing of a BLA for a Licensed Product, there is a period of 12 months where Roche is not conducting sufficient development activities with respect to the products made from the Licensed Intellectual Property. Following the Acquisition, the Company continues to retain its rights to its early stage product candidates in its pipeline existing prior to the Acquisition, rights to its AMP-Rx proprietary protein engineering platform that it had used to discover and develop innovative protein therapeutics to treat diseases of the eye and rights under the License Agreement with Roche. However, the Company expects that its primary business following the Acquisition will consist of the business conducted by Viventia immediately prior to the Acquisition. Liquidity The Company has financed its operations to date primarily through private placements of its common stock and preferred stock and convertible bridge notes, venture debt borrowings, its initial public offering ("IPO"), sales effected in an "at the market" offering through its agent, Cowen and Company, LLC, and the License Agreement, and as of September 30, 2016, the Company had cash and cash equivalents totaling approximately $30.7 million, net working capital of $25.5 million and an accumulated deficit of $119.8 million. The future success of the Company is dependent on its ability to develop its product candidates and ultimately upon its ability to attain profitable operations. The Company is subject to a number of risks similar to other early-stage life science companies, including, but not limited to, successful discovery and development of its product candidates, raising additional capital with favorable terms, development by its competitors of new technological innovations, protection of proprietary technology and market acceptance of the Company’s products. The successful discovery and development of product candidates requires substantial working capital which may not be available to the Company on favorable terms. The Company believes that its cash and cash equivalents of $30.7 million as of September 30, 2016, will be sufficient to fund the Company’s current operating plan into 2018. If the Company is unable to obtain adequate financing or engage in another strategic transaction on acceptable terms and when needed, the Company will be required to implement further cost reduction strategies. These factors and the factors described above continue to raise substantial doubt about the Company’s ability to continue as a going concern. The accompanying financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty. These financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). The consolidated financial statements include the accounts of Eleven Biotherapeutics, Inc., its wholly owned subsidiary, Viventia Bio Inc., and its indirect subsidiaries, Viventia Bio USA Inc. and Viventia Biotech (EU) Limited. All inter-company transactions and balances have been eliminated in consolidation.

Organization and Basis of Presentation

Eleven Biotherapeutics, Inc. (the “Company”), a Delaware corporation formed on February 25, 2008, is a biologics oncology company focused on designing, engineering and developing targeted protein therapeutics ("TPTs"). The Company's TPTs are single-protein therapeutics composed of targeting moieties genetically fused via linker domains to cytotoxic protein payloads that are produced through the Company's proprietary one-step manufacturing process. The Company targets tumor cell surface antigens that allow for rapid internalization into the targeted cancer cell and have limited expression on normal cells. The Company has designed its TPTs to overcome the fundamental efficacy and safety challenges inherent in existing antibody drug conjugates ("ADCs"), where a payload is chemically attached to a targeting antibody.

On September 20, 2016, the Company entered into a Share Purchase Agreement with Viventia Bio Inc., a corporation incorporated under the laws of the Province of Ontario, Canada (“Viventia”), the shareholders of Viventia named therein (the “Selling Shareholders”) and, solely in its capacity as seller representative, Clairmark Investments Ltd., a corporation incorporated under the laws of the Province of Ontario, Canada (“Clairmark”) (the “Share Purchase Agreement”), pursuant to which the Company agreed to and simultaneously completed the acquisition of all of the outstanding capital stock of Viventia from the Selling Shareholders (the “Acquisition”). In connection with the closing of the Acquisition, the Company issued 4,013,431 shares of its common stock to the Selling Shareholders, which represented approximately 19.9% of the voting power of the Company as of immediately prior to the issuance of such shares of the Company's common stock.

In addition, under the Share Purchase Agreement, the Company will be obligated to pay to the Selling Shareholders certain post closing contingent cash payments upon the achievement of specified milestones and based upon net sales, in each case subject to the terms and conditions set forth in the Share Purchase Agreement, including: (i) a one-time milestone payment of $12.5 million payable upon the first sale of Vicinium^TM or any variant or derivative thereof, other than Proxinium^TM (the “Purchased Product”), in the United States; (ii) a one-time milestone payment of $7.0 million payable upon the first sale of the Purchased Product in any one of certain specified European countries; (iii) a one-time milestone payment of $3.0 million payable upon the first sale of the Purchased Product in Japan; and (iv) and quarterly earn-out payments equal to two percent (2%) of net sales of the Purchased Product during specified earn-out periods. Such earn-out payments are payable with respect to net sales in a country beginning on the date of the first sale in such country and ending on the earlier of (i) December 31, 2033 and (ii) fifteen years after the date of such sale, subject to early termination in certain circumstances if a biosimilar product is on the market in the applicable country. Under the Share Purchase Agreement, the Company, its affiliates, licensees and subcontractors are required to use commercially reasonable efforts, for first seven years following the closing of the Acquisition, to achieve marketing authorizations throughout the world and, during the applicable earn-out period, to commercialize the Purchased Product in the United States, France, Germany, Italy, Spain, United Kingdom, Japan, China and Canada. Certain of these payments are payable to individuals or affiliates of individuals that became employees or members of the Board of Directors of the Company (the "Board").

Each of the Company, Viventia and the Selling Shareholders has agreed to customary representations, warranties and covenants in the Share Purchase Agreement. The Share Purchase Agreement also includes indemnification obligations in favor of the Company from the Selling Shareholders, including for breaches of representations, warranties, covenants and agreements made by Viventia and the Selling Shareholders in the Share Purchase Agreement. In connection with the closing of the Acquisition, the Company deposited 401,343 shares of its common stock (representing approximately 10% of the Company's common stock portion of the aggregate closing consideration owed to the Selling Shareholders pursuant to the Share Purchase Agreement) into an escrow fund for the purposes of securing the indemnification obligations of the Selling Shareholders to the Company for any and all losses for which the Company is entitled to indemnification pursuant to the Share Purchase Agreement. The Share Purchase Agreement also includes indemnification obligations in favor of the Selling Shareholders from the Company, including for breaches of representations, warranties, covenants and agreements made by the Company in the Share Purchase Agreement.

As a result of the Acquisition, Viventia became a wholly owned subsidiary of the Company (See Note 3).

License Transaction

On June 10, 2016, the Company entered into a License Agreement (the “License Agreement”) with F. Hoffmann-La Roche Ltd and Hoffmann-La Roche Inc. (collectively, “Roche”), which became effective on August 16, 2016. Under the License Agreement, the Company granted Roche an exclusive, worldwide license, including the right to sublicense, to its patent rights and know-how related to the Company’s monoclonal antibody EBI-031 or any other IL-6 antagonist anti-IL-6 monoclonal antibody, to make, have made, use, have used, register, have registered, sell, have sold, offer for sale, import and export any product containing such an antibody or any companion diagnostic used to predict or monitor response to treatment with such a product (collectively, the “Licensed Intellectual Property”).

Under the License Agreement, Roche is required to continue developing EBI-031 and any other product made from the Licensed Intellectual Property that contains an IL-6 antagonist anti-IL-6 monoclonal antibody (a “Licensed Product”) at its cost.

Financial Terms

The Company received an upfront license fee of $7.5 million from Roche and Roche agreed to pay up to an additional $262.5 million upon the achievement of specified regulatory, development and commercial milestones with respect to up to two unrelated indications. Specifically, an aggregate amount of up to $197.5 million is payable to the Company for the achievement of specified milestones with respect to the first indication: $72.5 million in development milestones, $50.0 million in regulatory milestones and $75.0 million in commercialization milestones. Additional amounts of up to $65.0 million are payable upon the achievement of specified development and regulatory milestones in a second indication.

The first development milestone payment for the first indication was paid in the amount of $22.5 million as a result of the IND application for EBI-031 becoming effective on or before September 15, 2016.

In addition, the Company is entitled to receive royalty payments in accordance with a tiered royalty rate scale, with rates ranging from 7.5% to 15% for net sales of potential future products containing EBI-031 and up to 50% of these rates for net sales of potential future products containing other IL-6 compounds, with each of the royalties subject to reduction under certain circumstances and to the buy-out options of Roche further described below.

Buy-Out Options

The License Agreement provides for two “option periods” during which Roche may elect to make a one-time payment to the Company and, in turn, terminate its diligence, milestone and royalty payment obligations under the License Agreement. Specifically, (i) Roche may exercise a buy-out option following the first dosing (“Initiation”) in the first Phase II study for a Licensed Product until the day before Initiation of the first Phase III study for a Licensed Product, in which case Roche is required to pay the Company $135 million within 30 days after Roche's exercise of such buy-out option and receipt of an invoice from the Company, or (ii) Roche may exercise a buy-out option following the day after Initiation of the first Phase III study for a Licensed Product until the day before the acceptance for review by the FDA or other regulatory authority of a biologics license application (“BLA”) or similar application for marketing approval for a Licensed Product in either the United States or in the European Union, in which case Roche is required to pay the Company, within 30 days after Roche’s exercise of such buy-out option and receipt of an invoice from the Company, $265 million, which amount would be reduced to $220 million if none of the Company’s patent rights containing a composition of matter claim covering any compound or Licensed Product has issued in the European Union.

Termination

The Company or Roche may each terminate the License Agreement if the other party breaches any of its material obligations under the License Agreement and does not cure such breach within a specified cure period. Roche may terminate the License Agreement following effectiveness by providing advance written notice to the Company or by providing written notice if the Company is debarred, disqualified, suspended, excluded, or otherwise declared ineligible from certain federal or state agencies or programs. The Company may terminate the License Agreement if, prior to the first filing of a BLA for a Licensed Product, there is a period of 12 months where Roche is not conducting sufficient development activities with respect to the products made from the Licensed Intellectual Property.

Following the Acquisition, the Company continues to retain its rights to its early stage product candidates in its pipeline existing prior to the Acquisition, rights to its AMP-Rx proprietary protein engineering platform that it had used to discover and develop innovative protein therapeutics to treat diseases of the eye and rights under the License Agreement with Roche. However, the Company expects that its primary business following the Acquisition will consist of the business conducted by Viventia immediately prior to the Acquisition.

Liquidity

The Company has financed its operations to date primarily through private placements of its common stock and preferred stock and convertible bridge notes, venture debt borrowings, its initial public offering ("IPO"), sales effected in an "at the market" offering through its agent, Cowen and Company, LLC, and the License Agreement, and as of September 30, 2016, the Company had cash and cash equivalents totaling approximately $30.7 million, net working capital of $25.5 million and an accumulated deficit of $119.8 million.

The future success of the Company is dependent on its ability to develop its product candidates and ultimately upon its ability to attain profitable operations. The Company is subject to a number of risks similar to other early-stage life science companies, including, but not limited to, successful discovery and development of its product candidates, raising additional capital with favorable terms, development by its competitors of new technological innovations, protection of proprietary technology and market acceptance of the Company’s products. The successful discovery and development of product candidates requires substantial working capital which may not be available to the Company on favorable terms.

The Company believes that its cash and cash equivalents of $30.7 million as of September 30, 2016, will be sufficient to fund the Company’s current operating plan into 2018. If the Company is unable to obtain adequate financing or engage in another strategic transaction on acceptable terms and when needed, the Company will be required to implement further cost reduction strategies. These factors and the factors described above continue to raise substantial doubt about the Company’s ability to continue as a going concern. The accompanying financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty.

These financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). The consolidated financial statements include the accounts of Eleven Biotherapeutics, Inc., its wholly owned subsidiary, Viventia Bio Inc., and its indirect subsidiaries, Viventia Bio USA Inc. and Viventia Biotech (EU) Limited. All inter-company transactions and balances have been eliminated in consolidation.