Eleven Biotherapeutics Presents Data on EBI-005

Eleven Biotherapeutics Presents Data on EBI-005, a Novel IL-1 Inhibitor Protein Therapeutic for Topical Treatment of Dry Eye Disease

EBI-005 is Clinical Candidate for Treating Dry Eye Disease with Potential in Other Ocular Surface Inflammatory Diseases

Data Presented at ARVO 2013 Annual Meeting Demonstrated EBI-005 is Safe and Well-Tolerated

ARVO 2013

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Eleven Biotherapeutics, a biopharmaceutical company designing and engineering novel and differentiated protein-based biotherapeutics for ocular diseases, announced today the presentation of data for EBI-005, the first IL-1 (Interleukin-1) signaling inhibitor designed for topical ocular administration, at the Association for Research in Vision and Ophthalmology (ARVO) 2013 Annual Meeting in Seattle, Washington. Eleven Biotherapeutics researchers presented data demonstrating that EBI-005 was safe and well-tolerated in both preclinical testing and in a clinical Phase 1a study in healthy volunteers. These data led to Eleven's Phase 1b clinical study of EBI-005 in subjects with dry eye disease, with top-line data from the Phase 1b study expected in the second half of 2013. In addition, these data support Eleven's new plans to evaluate the potential of EBI-005 in additional ocular surface inflammatory diseases, including severe allergic conjunctivitis.

In a poster presentation entitled "Early Clinical Development of EBI-005, a Potent Interleukin-1 (IL-1) Receptor-1 (R1) Blocker for Topical Ocular Treatment of Dry Eye Disease (DED)" Eleven Biotherapeutics researchers presented clinical data which demonstrated that:"EBI-005 is a novel therapeutic that enables the topical administration of a protein on the surface of the eye, and it also represents an important mechanism of blocking IL-1, a critical mediator of the inflammatory cascade that causes both the surface disease and symptoms suffered by patients with dry eye disease," said Abbie Celniker, PhD, Chief Executive Officer of Eleven Biotherapeutics. "With these data, we have successfully established that topical administration of EBI-005 is safe and well-tolerated in healthy volunteers, safety and tolerability are important criteria for patients who suffer from painful symptoms associated with ocular inflammation. We look forward to reporting data on our Phase 1b clinical study of EBI-055 in dry eye disease and moving expeditiously to advance into Phase 2 clinical studies in multiple ocular inflammatory diseases including continuation of the clinical program in dry eye disease as well as a new study in severe allergic conjunctivitis."

• EBI-005 was safe and well-tolerated in 16 normal healthy volunteers at two dose levels, with no systemic absorption, antibody formation, effect on vision, burning and irritation or serious adverse events.

• EBI-005 was successfully administered as a topical biologic – a novel approach for applying a protein therapeutic to treat ocular surface disease.

• The safety and tolerability profile demonstrated with EBI-005 in this Phase 1a study informed the design of the ongoing Phase 1b study in patients with DED.

In a poster presentation entitled "Preclinical Development of EBI-005: a Potent Interleukin-1 (IL-1) Receptor-1 (R1) Blocker for Topical Ocular Administration was Safe in GLP Toxicology Studies and Active in a Mouse Model of Dry Eye Disease (DED)" Eleven Biotherapeutics researchers presented preclinical data which demonstrated that:

• EBI-005 distributed well to ocular surface tissues and had low systemic exposure. This feature is important to reduce the risk of immune suppression related adverse events associated with systemic IL-1 antagonism.

• EBI-005 did not accumulate in the eye, even after multiple daily doses, demonstrating the potential for chronic administration in a variety of ocular surface disorders including dry eye disease and severe allergic conjunctivitis.

• High thermal stability shown by EBI-005 creates the potential for an ambient temperature-stable product.

In a poster presentation entitled "Use of galectin-3 fusions to extend the surface residence time of proteins topically applied to the eye" Eleven Biotherapeutics researchers presented data which demonstrated that:

• Galectin-3 leads to longer residence time of model proteins, and modifications to an IL-1 antagonist may result in improved potency, potentially enabling reduced dosing frequency for future topically administered protein-based therapeutics.

About Dry Eye Disease

Dry eye disease (DED) is an ocular surface inflammatory condition induced by desiccating stress and mediated by an inflammatory cascade regulated by IL-1. DED affects approximately 10% of individuals between 30 to 60 years of age, and up to 15% of those over 65. Despite its prevalence and impact on quality of life, DED is under-diagnosed, under-treated and has few safe and effective treatment options.

About EBI-005

Eleven Biotherapeutics' lead product candidate, EBI-005, is a novel, interleukin-1 (IL-1) receptor antagonist currently in Phase 1b clinical development as a rationally designed topical protein for the treatment of inflammatory diseases at the surface of the eye. The mechanism of action for EBI-005 was validated in a clinical proof-of-concept study in which IL-1 blockade was generally safe and well-tolerated with significant improvements in both signs and symptoms of dry eye disease. EBI-005 has been designed to have superior physical, pharmaceutical and therapeutic properties including topical ophthalmic administration for the treatment of ocular diseases including dry eye and severe ocular allergy. In preclinical studies, EBI-005 demonstrated optimal properties for the treatment of dry eye disease, such as high potency, very low systemic exposure, which minimizes the potential for adverse effects and thermal stability, providing for a room-temperature stabile product.

About Eleven Biotherapeutics

Eleven Biotherapeutics creates novel and differentiated biotherapeutics: first-of-a-kind protein-based drugs with significantly improved physical, pharmaceutical, and therapeutic benefits. The company's AMP-Rx™ product engine brings capabilities beyond conventional approaches for making protein therapeutics, opening up new territory for the products to have novel structures, enhanced biophysical properties, and more effective targeting in disease pathways. Eleven's success is built on designing proteins 'fit for purpose' that are rationally designed to have ideal therapeutic characteristics and result in best-in-class biotherapeutic products for a wide range of diseases. The Cambridge, Mass.-based company was founded in 2010 by life science investors Flagship Ventures and Third Rock Ventures and world-renowned scientific experts. For more information, please visit www.elevenbio.com.