Shares of Eyegate Pharmaceuticals Inc. (NASDAQ:EYEG) rose 54.8% to $7.09 Friday on news that its ocular bandage gel (OBG) proved superior to standard of care in healing corneal wounds following photorefractive keratectomy (PRK) surgery. The pivotal top-line data will allow the Waltham, Mass.-based company to submit a de novo application to the FDA for commercialization in the first half of 2020, said CEO Stephen From. If approved, the OBG eye drop would be the first product indicated to repair corneal epithelial defects, as well as the first prescription hyaluronic acid (HA) eye drop in the U.S., creating new competition for widely used bandage contact lenses (BCL).
PRK is considered an effective alternative for people seeking surgical correction of refractive errors – nearsightedness, farsightedness, astigmatism and presbyopia – who aren't suitable candidates for LASIK (laser-assisted in situ keratomileusis). But LASIK isn't right for everyone, especially those with inadequate corneal thickness, larger pupil size, a history of dry eye, or anterior basement membrane disease, the company notes. The military even prefers PRK as a refractive surgery due to the stability of the PRK incision and the absence of risk for flap dislocation during military active duty, according to Eyegate.
Despite the good fit of PRK for some, there are downsides, too: common complications of the procedure can include postoperative pain secondary to the epithelial defects, risk of corneal infection prior to re-epithelization of the large epithelial defect, corneal haze formation, decreased contrast sensitivity and slower visual recovery, the company said.
Current standard-of-care treatment following PRK surgery is a BCL, such as Johnson & Johnson Vision Care Inc.'s Acuvue Oasys. Topical antibiotics and anti-inflammatories are also used. If approved, Eyegate's OBG could replace the use of BCLs.
The candidate, a natural product classified as a device because of the way in which Eyegate has modified it, is a topically applied 0.75% crosslinked thiolated carboxymethyl HA (CMHA-S) formulation. Applied to the eye with an everyday dropper bottle, it creates a thin protective coating for the damaged surface of the eye following PRK surgery, serving to facilitate corneal re-epithelization by protecting the ocular surface. It does so by sitting on the surface of the eye for as long as two hours without breaking down rather than quickly degrading into small oligos in the way that unmodified HA does.
"To be able to say that a liquid eye drop can do as well as a mechanical piece of material that covers and protects the surface of the eye is amazing," From said. BCLs "do a great job and we beat it with an eye drop," he said.
Though human use of CMHA-S in ocular applications is licensed to Eyegate by Biotime Inc., the gel is already available commercially as a veterinary device for use in managing superficial corneal ulcers. Manufactured by Sentrx Animal Care Inc. and sold in the U.S. by Bayer Animal Health as Remend Corneal Repair, it has been used for more than five years in dogs, cats and horses, without adverse effects, according to Eyegate. The composition of the veterinary product is identical to that of Eyegate's OBG.
Prior clinical support
Prior to the new pivotal data, Eyegate has reported results from two additional trials evaluating the ability of its OBG to manage ocular surface re-epithelialization following PRK. In the first quarter of 2017, it reported that, among 39 patients with large corneal epithelial defects following PRK surgery during an initial prospective study, 83.3% of those treated with OBG alone achieved complete wound closure by day three vs. 53.8% of patients who received standard-of-care treatment.
In a similar study, reading out in the fourth quarter of 2018, 45 participants undergoing bilateral PRK surgery were randomized to receive either one of two different OBG dosing regimens or standard of care following the procedure. Both OBG dosing regiments outperformed the standard of care in the number of eyes healed at day three and day four post-surgery.
In addition to PRK, Eyegate is developing its OBG for the treatment of punctate epitheliopathies, which provide an "early sign of epithelial compromise and is associated with a variety of pathologic ocular inflammatory conditions, including ocular causes, as well as systemic diseases," it said.
Further data to come
While Eyegate's team has data on its primary endpoint, they're still waiting for demographic and safety data next week. A report of the full dataset will follow. That said, From expressed confidence Friday. "We know how safe our product is," he said. "We were just wanting to make sure it works." With the primary endpoint of the pivotal study met, the company can now move its de novo application ahead toward filing.
With the potential patient population for OBG being relatively big, Eyegate's team still needs to figure out how it might be commercialized and launched. "Strategically, it would probably make sense for us to be out looking for someone that we could do some form of strategic transaction with," From said.