Using a novel ocular injection platform to deliver drug to the suprachroidal space (SCS) at the back of the eye, Clearside Biomedical (NASDAQ:CLSD) is relentlessly pursuing treatments for blinding diseases with a late-stage pipeline for macular edema associated with uveitis and retinal vein occulusion and DME, as well as an early development program for wet AMD.
“Drug delivery to the SCS has the potential to offer more optimal therapy through high bioavailability, even and efficient distribution throughout the eye, and rapid onset, with a better side effect profile,” president and CEO, Daniel White, says in an interview with BioTuesdays.
“The objectives of our program are rapid vision gains, sustained better vision, fewer injections and an improved benefits-to-risk ratio consistent across all patients, using the SCS microinjection.
Last month, Clearside launched a $36-million stock offering and granted underwriters an over-allotment option to sell an additional 600,000 shares at $9 each. Proceeds will be used for its clinical trial program with Zuprata and axitinib. Clearside also was added to the NASDAQ Biotechnology Index in mid-December.
Mr. White says a pivotal Phase 3 trial is underway treating uveitis patients, with data expected in the second half this year or early 2018 and a Phase 3 trial is being initiated with RVO patients. In addition, a Phase 1/2 study is underway in DME and the company expects to file an IND for the treatment of wet AMD in the first half this year.
“We estimate that there are nearly five million people in the U.S. diagnosed with non-infectious uveitis, RVO, DME and wet-AMD, which are the back-of-the-eye diseases we target,” he adds. Some 1,700 retinal specialists treat these patients. “Our intent is to establish a commercial infrastructure with an estimated sales force of 35-to-45 people to reach these specialists.”
Mr. White explains that administration of corticosteroids is the most common treatment for all symptoms of uveitis, including macular edema. There are some 350,000 uveitis patients in the U.S., of which 33%, or 115,000 people, have macular edema, a build-up of fluid in the macula, which causes the macula to swell and thicken, resulting in distorted vision.
In an earlier Phase 2 study in 22 uveitis patients with macular edema, Zuprata achieved a statistically significant reduction in retinal thickness as well as improvements in Best Corrected Visual Acuity (BCVA) on average 2 lines of improvement.
In addition, there were no serious adverse events related to treatment or discontinuation of the study as well as no steroid-related increase in intraocular pressure.
The ongoing six-month Phase 3 study in uveitis is expected to recruit 150 patients at 50 clinical sites, with 90 patients receiving Zuprata and 60 receiving a sham injection. The primary endpoint is superiority of BCVA from treatment.
According to Mr. White, macular edema is the most common cause of vision loss for patients following RVO and affects some 2.2 million people in the U.S. First line treatment is 10-to-12 annual anti-VEGF injections of Eylea, Lucentis and/or off-label Avastin.
Anti-VEGF drugs work by stopping a protein called vascular endothelial growth factor (VEGF) produced by cells in the retina and leading to new blood vessel growth, which is a major problem in a number of eye diseases.
Steroids like fluocinolone and dexamethasone also appear to have a reasonable track record providing efficacy in DME subjects, but adverse events, like development of cataracts in certain patients often appear to compromise visual gains seen within the first few months