Eleven Biotherapeutics Initiates Pivotal Phase 3 Clinical Study with EBI-005 in Dry Eye Disease

Eleven Biotherapeutics Initiates Pivotal Phase 3 Clinical Study with EBI-005 in Dry Eye Disease

February 18, 2014

Patient Randomization and Dosing Underway

CAMBRIDGE, Mass.--(BUSINESS WIRE)-- Eleven Biotherapeutics (NASDAQ: EBIO), a clinical-stage biopharmaceutical company discovering and developing protein therapeutics to treat diseases of the eye, today announced that patient randomization and dosing are underway in the Company's first pivotal Phase 3 clinical study of EBI-005 for the treatment of moderate to severe dry eye disease (DED), the OASIS study (A Multi-Center, Double-Masked, Randomized, Controlled, Efficacy and Safety Study of EBI-005 5 mg/mL Topical Ophthalmic Solution Versus Vehicle Control In Subjects With Moderate to Severe Dry Eye Disease). EBI-005, the Company's most advanced product candidate generated using its AMP-Rx platform, is a novel, topically administered Interleukin-1 (IL-1) receptor blocker currently in development for the treatment of dry eye disease and allergic conjunctivitis. EBI-005 was designed to bind and block the IL-1 receptor to prevent transmission of biological signals responsible for many of the signs and symptoms of ocular surface diseases. This pivotal Phase 3 trial will include approximately 650 subjects in the U.S. Subjects will be randomized to receive EBI-005 or a vehicle-control. The co-primary endpoints of the study are change in corneal fluorescein staining score (a sign of dry eye disease) and improvement in pain and discomfort (a symptom of dry eye disease). The safety and tolerability of EBI-005 compared to vehicle-control will also be evaluated.

This pivotal Phase 3 trial was designed based on the results observed in the Company's Phase 1b/2a clinical trial of EBI-005 in patients with moderate to severe dry eye disease. Based on estimates of patient enrollment, the Company expects that top line data from this pivotal Phase 3 study will be available in early 2015.

About EBI-005

Eleven Biotherapeutics' most advanced product candidate is EBI-005, which was designed, engineered and generated using the Company's AMP-Rx platform and is being developed as a topical treatment for dry eye disease and allergic conjunctivitis. In 2013, Eleven Biotherapeutics completed a Phase 1b/2a clinical trial of EBI-005 in patients with moderate to severe dry eye disease. The EBI-005 program is based on the role that elevated levels of the inflammatory cytokine interleukin-1, or IL-1, play in the initiation and maintenance of the inflammation and pain associated with dry eye disease and the redness and itching associated with allergic conjunctivitis.

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. The Company'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.

Cautionary Note on Forward-Looking Statements

Any statements in this press release about future expectations, plans and prospects for the Company, including statements about the Company's strategy, future operations, clinical development of the Company's therapeutic candidates, including expectations regarding patient enrollment and availability of results, 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 and other factors discussed in the "Risk Factors" section of the Company's prospectus filed with the Securities and Exchange Commission pursuant to Rule 424(b)(4) on February 6, 2014. 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.

Eleven Biotherapeutics

Cameron Wheeler, PhD

617-858-0927

cameron@elevenbio.com

or Media: The Yates Network Gina Nugent,

617-460-3579

gina@theyatesnetwork.com

Source: Eleven Biotherapeutics