Eleven Biotherapeutics Reports Phase 3 Data on Isunakinra (EBI-005) in Allergic Conjunctivitis

-Isunakinra Misses Primary Endpoint of Ocular Itching-

-Company Plans to Advance Development of EBI-031 for Diabetic Macular
Edema and Uveitis with an IND Submission Planned for the First Half of

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 top-line
results from the Phase 3 clinical trial of its lead drug candidate,
isunakinra (EBI-005), for the treatment of severe allergic
conjunctivitis. In this trial, there were no statistically significant
differences between the isunakinra treated group and the vehicle control
group on the primary endpoint of ocular itching or on any secondary
endpoints. Isunakinra was generally well tolerated, with 94% of the
patients completing the trial and there were no serious adverse events

The multi-center, double-masked, randomized, vehicle controlled Phase 3
clinical trial was designed to evaluate the safety and efficacy of
isunakinra for up to four 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.

“We are disappointed that isunakinra failed to meet its primary
endpoint, and based on these overall results we see no immediate path
forward in allergic conjunctivitis,” said Abbie Celniker, PhD, President
and CEO of Eleven Biotherapeutics. “Our efforts will be focused on
submitting an investigational new drug application (IND) for EBI-031 in
diabetic macular edema in the first half of 2016. In addition, we plan
to provide an update on our corporate strategy later this quarter during
our 2015 year-end financial results conference call.”

Michael Goldstein, MD, Chief Medical Officer of Eleven Biotherapeutics
commented, “Despite this outcome, we plan to continue to assess
interleukin-1 (IL-1) genotyping in ocular surface diseases by evaluating
data from patient subsets in this clinical trial identified to be high
producers of IL-1.”

Cash Position

As of December 31, 2015, Eleven had approximately $36.1 million of cash
and cash equivalents. As a result of the outcome of this trial, Eleven
is required to fund a cash collateral account with Silicon Valley Bank
in an amount equal to approximately $15.1 million, representing the
outstanding amounts under its loan agreement with Silicon Valley Bank.
Eleven Biotherapeutics currently expects its unrestricted cash and cash
equivalents will enable the Company to fund its operating plans into the
fourth quarter of 2016.

About EBI-031

Eleven Biotherapeutics’ most advanced preclinical product candidate is
EBI-031 for treatment of diabetic macular edema, or DME, and uveitis.
EBI-031 was designed and engineered for intravitreal delivery using the
Company’s AMP-Rx platform. EBI-031 is a potent blocker of both free IL-6
and IL-6 complexed to the soluble IL-6 receptor (IL-6R) and has
demonstrated a longer vitreal retention time in preclinical models than
antibodies and antibody like molecules approved for intravitreal
injection. The Company is undertaking manufacturing development work and
nonclinical safety studies to support the submission of an
investigational new drug application, or IND, to the FDA in the first
half of 2016 for the purpose of conducting clinical trials of EBI-031 in
DME and uveitis.

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.

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, advancement or maturation of its product
candidates and product pipeline, clinical development of the Company’s
therapeutic candidates, including expectations regarding timing of
clinical trials or regulatory submissions, regulatory requirements for
initiation of clinical trials and registration of product candidates,
the sufficiency of its cash resources 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 clinical trials, whether results of early
clinical trials or preclinical studies 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 September 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


Eleven Biotherapeutics
Leah Monteiro, 617-714-061