Omeros Reports OMS302 Clinical Data Presented at the Annual ASCRS and ASOA Symposium and Congress

  Omeros Reports OMS302 Clinical Data Presented at the Annual ASCRS and ASOA
                            Symposium and Congress

-- Data Show that OMS302 Maintains Pupil Size During Lens Replacement Surgery
by Not Only Promoting Mydriasis but also by Preventing Miosis --

PR Newswire

SEATTLE, April 25, 2013

SEATTLE, April 25, 2013 /PRNewswire/ --Omeros Corporation (NASDAQ: OMER)
today reported analyses of Phase 2 and Phase 3 clinical data showing the
favorable impact of OMS302 on reducing the incidence of miosis (pupil
constriction) during intraocular lens replacement (ILR). OMS302, which
contains a mydriatic (pupil-dilating) agent and an anti-inflammatory agent, is
the Company's product being developed for use during ILR, including cataract
surgery and refractive lens exchange. These analyses were presented on April
21 at the Annual American Society of Cataract and Refractive Surgery (ASCRS)
and American Society of Ophthalmic Administrators (ASOA) Symposium and
Congress in San Francisco.

The clinical data presented at the ASCRS meeting show that, in the setting of
all treatment- and control-group patients receiving standard-of-care
preoperative mydriatic topical drops, OMS302 reduces the occurrence of pupil
constriction of 2.5 mm or more and the incidence of the pupil constricting to
less than 6 mm in diameter throughout surgery. These two measures are widely
recognized by ophthalmologic surgeons as important for successful ILR
procedures.

"Intraoperative miosis is a challenge to all lens replacement procedures,
increasing both surgical time and the risk of an unsuccessful outcome," stated
Eric B. Donnenfeld, M.D., clinical professor of ophthalmology at New York
University and newly elected president of the ASCRS. "These data show that
OMS302 successfully addresses this challenge. Given the well-recognized need
for a product like OMS302 in lens replacement procedures, I expect that it
will be widely and rapidly adopted by ophthalmologic surgeons."

"The strong reception that OMS302 received from the thought leaders at the
ASCRS and ASOA Congress was gratifying," stated Gregory A. Demopulos, M.D.,
chairman and chief executive officer of Omeros. "When presented with the data
package for OMS302, ophthalmologic surgeons uniformly appreciate the product's
benefits and expect that it will become an important part of standard practice
for intraocular lens replacement. We look forward to making OMS302 available
to surgeons and their patients."

About Omeros' OMS302 Program

OMS302 is Omeros' product being developed for use during intraocular lens
replacement (ILR), including cataract surgery and refractive lens exchange.
OMS302 is a proprietary combination of the mydriatic (pupil dilating) agent
phenylephrine and the anti-inflammatory agent ketorolac. Omeros recently
completed its successful OMS302 Phase 3 clinical program and expects to submit
a New Drug Application to the U.S. Food and Drug Administration this quarter
and a Marketing Authorization Application to the European Medicines Agency in
mid-2013.

ILR involves replacement of the original lens of the eye with an artificial
intraocular lens. These procedures are typically performed to replace a lens
opacified by a cataract or to correct a refractive error of the lens (i.e.,
refractive lens exchange). OMS302 is added to standard irrigation solution
used in ILR and delivered within the eye to maintain intraoperative mydriasis
(pupil dilation), to prevent surgically induced miosis (pupil constriction),
and to reduce postoperative pain and irritation. Maintenance of mydriasis is
critical to the safety and surgical ease of the procedure. Intraoperative
pupil constriction increases the risk of injury to intraocular structures and
can substantially prolong surgical time.

About Omeros Corporation

Omeros is a clinical-stage biopharmaceutical company committed to discovering,
developing and commercializing products targeting inflammation, coagulopathies
and disorders of the central nervous system. The Company's most clinically
advanced product candidates, OMS302 for lens replacement surgery and OMS103HP
for arthroscopy, are derived from its proprietary PharmacoSurgery™ platform
designed to improve clinical outcomes of patients undergoing a wide range of
surgical and medical procedures. Omeros has five clinical development
programs. Omeros may also have the near-term capability, through its GPCR
program, to add a large number of new drug targets and their corresponding
compounds to the market. Behind its clinical candidates and GPCR platform,
Omeros is building a diverse pipeline of protein and small-molecule
preclinical programs targeting inflammation, coagulopathies and central
nervous system disorders.

Forward-Looking Statements

This press release contains forward-looking statements as defined within the
Private Securities Litigation Reform Act of 1995, which are subject to the
"safe harbor" created by those sections. These statements include, but are not
limited to, Omeros' expectations regarding when it will submit marketing
applications for OMS302; and that Omeros may have capability, through its GPCR
program, to add a large number of new drug targets and their corresponding
compounds to the market. Forward-looking statements are based on management's
beliefs and assumptions and on information available to management only as of
the date of this press release. Omeros' actual results could differ materially
from those anticipated in these forward-looking statements for many reasons,
including, without limitation, the risks, uncertainties and other factors
described under the heading "Risk Factors" in the Company's Annual Report on
Form 10-K filed with the Securities and Exchange Commission on March 18, 2013.
Given these risks, uncertainties and other factors, you should not place undue
reliance on these forward-looking statements, and the Company assumes no
obligation to update these forward-looking statements publicly, even if new
information becomes available in the future.

SOURCE Omeros Corporation

Contact: Jennifer Cook Williams, Cook Williams Communications, Inc.,
+1-360-668-3701, jennifer@cwcomm.org