78% of Patients Required No Additional Treatment in the Trial Arm with Concomitant Suprachoroidally Administered Zuprata™ and Intravitreally Administered Eylea^®

Patients Reached an Average BCVA Improvement of 19 Letters Over a 3-Month Period

ALPHARETTA, Ga., July 26, 2016 (GLOBE NEWSWIRE) — Clearside Biomedical, Inc. (NASDAQ:CLSD), a late-stage clinical biopharmaceutical company developing first-in-class drug therapies to treat blinding diseases of the eye, today reports additional top-line data from its Phase 2 clinical trial (TANZANITE).  The 46-patient Phase 2 trial, with top-line results originally reported in April 2016, evaluated the treatment of macular edema associated with retinal vein occlusion (RVO) in treatment-naïve patients, and included an “active” arm of concomitant suprachoroidally administered Zuprata™, Clearside’s proprietary form of triamcinolone acetonide and intravitreally administered aflibercept (Eylea^®, Regeneron Pharmaceuticals, Inc.) compared to an Eylea-alone “control” arm. Seventy eight percent (78%, or 18/23) of patients in the active arm of the TANZANITE trial did not require additional treatments during the three-month trial compared to 30% (7/23) in the control arm (p=0.003).

In this trial, patients were randomized to receive either one intravitreal injection of Eylea and a concomitant suprachoroidal injection of Zuprata or one intravitreal injection of Eylea. After randomization, patients were assessed once per month for three months. The 23 patients in each of the two treatment arms were evaluated for the need to receive additional intravitreal injections of Eylea alone at months 1, 2 and 3 after the initial treatment using specified criteria to determine if they continued to experience macular edema or reductions in visual acuity.

In April 2016, Clearside announced that, based on preliminary results, the trial had met its primary endpoint, showing that approximately 60% fewer additional intravitreal Eylea treatments were needed in the active arm (9 injections) than in the Eylea-alone control arm (23 injections) during the three-month observation period following initial treatment (p=0.013).  The additional treatments in the “active” arm were concentrated in a total of five patients, with two of these patients requiring additional Eylea injections at months 2 and 3 and three additional patients requiring a single additional Eylea injection at month 3.

The secondary endpoints in the trial included the mean change from baseline in best corrected visual acuity (BCVA) and central subfield thickness. For the BCVA endpoint, at month 1, patients in the active arm had an average improvement of approximately 16 letters in BCVA compared to approximately 11 letters of improvement for patients in the control arm. At the end of the three-month observation period, patients in the active arm had an average improvement of approximately 19 letters, while patients in the control arm maintained their same level of improvement at approximately 11 letters.    

“Two of the primary needs in treating retinal disease are achieving maximal visual improvements as quickly as possible and then maintaining those visual gains for longer periods of time to provide the potential to reduce the need for frequent treatments, especially in a difficult to treat retinal vascular disease like RVO,” said Daniel H. White, CEO and President of Clearside. “The data from the TANZANITE trial supports the potential of suprachoroidal delivery to yield visual acuity gains more rapidly with fewer treatments using Zuprata concomitantly with VEGF inhibitors like Eylea in retinal vascular disease, and these clinical data provide support for pursuing further development of Zuprata for the treatment of retinal vascular diseases like RVO and diabetic macular edema (DME).”

Clearside expects to have an end-of-Phase 2 meeting with the U.S. Food and Drug Administration (FDA) in the second half of 2016, and, if feedback from the FDA at that meeting is positive, Clearside intends to commence a Phase 3 clinical program for the treatment of macular edema associated with RVO in the first half of 2017.

About RVO

RVO is a sight-threatening disorder resulting from the blockage of one of the veins carrying blood out of the retina. RVO is estimated to affect more than 16 million adults worldwide, according to a 2010 study published in the journal Ophthalmology, and it is estimated that RVO affects 2.2 million adults in the United States. In RVO, the blockage of a retinal vein can lead to poor blood circulation, low oxygen and, sometimes, inflammation in the eye. A blocked vein will leak its contents of blood and fluid. Bleeding within the retina and swelling from the fluid can result in macular edema.

About Clearside Biomedical, Inc.

Clearside Biomedical, Inc., headquartered in Alpharetta, GA, is a publicly-traded, late-stage clinical biopharmaceutical company developing innovative first-in-class drug therapies to treat blinding diseases of the eye using Clearside’s proprietary suprachoroidal space microinjector to reach diseased tissue through the suprachoroidal space. Clearside holds intellectual property protecting the delivery of drugs of any type through the suprachoroidal space to reach the back of the eye. Clearside has a portfolio of clinical and pre-clinical programs using drug administration through the suprachoroidal space to provide a route of access to treat diseases of the back-of-the-eye such as RVO, uveitis, neovascular age-related macular degeneration (wet AMD) and DME. Clearside is currently enrolling patients in a Phase 3 clinical trial (Peachtree) for the treatment of patients with macular edema associated with non-infectious uveitis and has initiated IND-enabling studies for the treatment of wet AMD. Visit www.clearsidebio.com for more information.

Cautionary Note Regarding Forward Looking Statements

Any statements contained in this press release that do not describe historical facts may constitute forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995.  These statements may be identified by words such as “believe”, “expect”, “may”, “plan”, “potential”, “will”, and similar expressions, and are based on Clearside’s current beliefs and expectations. These forward-looking statements include expectations regarding the clinical development of Clearside’s product candidates. These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements. Risks and uncertainties that may cause actual results to differ materially include uncertainties inherent in the conduct of clinical trials, Clearside’s reliance on third parties over which it may not always have full control, and other risks and uncertainties that are described in the Risk Factors section of Clearside’s Registration Statement on Form S-1 (File No. 333-208916) declared effective by the Securities and Exchange Commission (SEC) on June 1, 2016, and Clearside’s other Periodic and Current Reports filed with the SEC. These documents are available under the “Investor Relations” section of Clearside’s website at http://www.clearsidebio.com. Any forward-looking statements speak only as of the date of this press release and are based on information available to Clearside as of the date of this release, and Clearside assumes no obligation to, and does not intend to, update any forward-looking statements, whether as a result of new information, future events or otherwise.

Contacts

Clearside Biomedical, Inc.

Company: Charles Deignan Chief Financial Officer 678-270-4005 [email protected]

Investors: Matthew Beck The Trout Group 646-378-2933 [email protected]