Eleven Biotherapeutics Completes Enrollment in Pivotal Phase 3 Study of Isunakinra (EBI-005) in Patients with Allergic Conjunctivitis

-Eleven Granted Isunakinra as the International Nonproprietary Name for EBI-005-

CAMBRIDGE, Mass.--(BUSINESS WIRE)-- Eleven Biotherapeutics, Inc. (NASDAQ: EBIO), a clinical-stage biopharmaceutical company discovering and developing protein therapeutics to treat diseases of the eye, today announced the completion of patient enrollment in its first pivotal, Phase 3 clinical study of isunakinra (EBI-005) in patients with moderate to severe allergic conjunctivitis. Isunakinra, a topical, novel interleukin-1 (IL-1) receptor blocker, is Eleven’s lead drug candidate in development for the treatment of moderate to severe allergic conjunctivitis.

“The completion of patient enrollment in this study of moderate to severe allergic conjunctivitis keeps us on target for a first quarter 2016 announcement of top-line results,” said Abbie Celniker, Ph.D., President and Chief Executive Officer of Eleven Biotherapeutics. “Isunakinra is a drug candidate with potential to treat patients who are not well addressed with standard of care therapies for ocular allergy including forms of allergic conjunctivitis that can be chronic and in some cases sight threatening.”

This multi-center, double-masked, randomized, vehicle controlled Phase 3 pivotal trial is designed to evaluate the safety and efficacy of isunakinra for up to four and one half weeks in patients with moderate to severe allergic conjunctivitis in an environmental setting. A total of 258 patients were randomized 1:1 to receive treatment with isunakinra or with vehicle-control. If the results of this first Phase 3 trial are favorable, Eleven intends to initiate a second Phase 3 trial in the second half of 2016.

This Phase 3 study was designed and initiated following the completion of a Phase 2 study in October 2014, in which isunakinra exhibited biological activity in improving the symptoms of late-phase allergic responses in patients with moderate to severe allergic conjunctivitis who were not well treated with standard of care therapy. This included statistically significant improvements in mean change from baseline in patient reported ocular itching, tearing and associated nasal symptoms compared to vehicle-control at the second to last and final assessment time points following allergen exposure in a modified, repeat direct conjunctival allergen provocation test (CAPT) model.

About Allergic Conjunctivitis

Allergic conjunctivitis (AC) affects the ocular surface and is characterized by symptoms of ocular itching, ocular tearing, ocular redness and associated nasal symptoms. If allergic conjunctivitis is left untreated or becomes severe, patients may suffer chronic ocular pain and distortion of vision that can significantly reduce their quality of life. Allergic conjunctivitis is a common cause of patient visits to eye care professionals in the United States. Allergic conjunctivitis affects 15% to 40% of the U.S. population. According to Eleven's primary market research, in the United States 11 million patients seek medical treatment for allergic conjunctivitis annually. Of these patients, approximately 4 million have moderate allergic conjunctivitis and approximately 1.8 million have severe allergic conjunctivitis.

About Isunakinra (EBI-005)

Eleven Biotherapeutics' most advanced product candidate is isunakinra, a novel, topically-administered interleukin-1 (IL-1) receptor blocker in development as a protein therapeutic for inflammatory diseases at the surface of the eye. The isunakinra program is based on the role that elevated levels of the inflammatory cytokine IL-1 play in the initiation and maintenance of the inflammation, pain, redness, itching and other symptoms associated with ocular surface diseases. Isunakinra is currently in Phase 3 clinical development for the treatment of moderate to severe allergic conjunctivitis. In a completed Phase 2 clinical trial, isunakinra exhibited biological activity in improving the symptoms of late-phase allergic responses in patients with moderate to severe allergic conjunctivitis in a CAPT model.

About Eleven Biotherapeutics

Eleven Biotherapeutics, Inc. is a clinical-stage biopharmaceutical company with a proprietary protein engineering platform, called AMP-Rx, that it applies to the discovery and development of protein therapeutics to treat diseases of the eye. Eleven’s therapeutic approach is based on the role of cytokines in diseases of the eye, the Company’s understanding of the structural biology of cytokines and the Company’s ability to rationally design and engineer proteins to modulate the effects of cytokines. Cytokines are cell signaling molecules found in the body that can have important inflammatory effects. For more information please refer to the Company's website www.elevenbio.com.

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Any statements in this press release about future expectations, plans and prospects for the Company, including statements about the Company's strategy, future operations, advancement or maturation of its product candidates and product pipeline, clinical development of the Company's therapeutic candidates, including expectations regarding timing of initiation of clinical trials, patient enrollment and availability of results, regulatory requirements for initiation of clinical trials and registration of product candidates and other statements containing the words "anticipate," "believe," "estimate," "expect," "intend," "may," "plan," "predict," "project," "target," "potential," "will," "would," "could," "should," "continue," and similar expressions, constitute forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including: the uncertainties inherent in the initiation and conduct of clinical trials, availability and timing of data from ongoing clinical trials, whether results of early clinical trials will be indicative of the results of future trials, the adequacy of any clinical models, uncertainties associated with regulatory review of clinical trials and applications for marketing approvals and other factors discussed in the "Risk Factors" section of the Company's quarterly report on Form 10-Q for the quarter ended June 30, 2015 as filed with the Securities and Exchange Commission and other reports on file with the Securities and Exchange Commission. In addition, the forward-looking statements included in this press release represent the Company's views as of the date hereof. The Company anticipates that subsequent events and developments will cause the Company's views to change. However, while the Company may elect to update these forward-looking statements at some point in the future, the Company specifically disclaims any obligation to do so. These forward-looking statements should not be relied upon as representing the Company's views as of any date subsequent to the date hereof.