Cacicol20® in Corneal Wound Healing and Nerve Regeneration After Phototherapeutic Keratectomy (CACICOL-PTK)

Cacicol20® in Corneal Wound Healing and Nerve Regeneration After Phototherapeutic Keratectomy of the Anterior Cornea: A Randomized Double-Blinded Placebo-Controlled Study

Region Östergötland, Linkoeping University, Sahlgrenska University Hospital, Sweden, Laboratoires Thea

The objective of this clinical study is to test the efficacy of CACICOL20® (RGTA OTR 4120) in improving wound healing and nerve regeneration in the anterior cornea, in a patient population undergoing therapeutic laser treatment for corneal dystrophy or recurrent corneal erosions.

Patients undergoing various surgical treatments of the cornea often suffer from a neural deficit, due to nerves being severed or removed completely during surgery. This can result in pain, impaired epithelial wound healing, reduced tear production, symptoms of dry eye, and loss of ocular surface sensitivity/blink reflex. In addition, surgical wound healing can be accompanied by undesirable formation of scar tissue, which can limit postoperative visual acuity. The investigators' prior clinical experience with patients having undergone surgery of the anterior cornea is that neural recovery is slow and incomplete, while in certain situations scar tissue can form and limit the visual recovery. In this context, CACICOL20®, a regenerative agent approved for use in healing corneal wounds, presents an interesting opportunity for improving postoperative corneal nerve regeneration and a potentially more rapid restoration of the extracellular matrix environment postoperatively, which can lead to improved neural and visual outcomes. The investigators will therefore evaluate the efficacy of CACICOL20® in a randomized, double-blinded clinical study, to evaluate its ability to promote corneal nerve regeneration, epithelial wound healing, and ocular surface recovery postoperatively. Upon inclusion and signing of informed consent, patients undergo preoperative examination. Upon satisfying study criteria, patients are randomized to either treatment or placebo group. Group identity is masked to subjects and to investigators (double-blind). Subjects then undergo therapeutic laser treatment of the cornea in a single clinic, followed by instillation of treatment or placebo in the form of 3 eye drops total (to be given once immediately after surgery, once 2 days after surgery, and a final time 4 days after surgery). Postoperative eye examinations are conducted on days 2 and 7 and at month 6 and 12. Examinations include clinical measurement of various eye and corneal wound healing parameters.

Corneal Dystrophy, Epithelial Basement Membrane, Epithelial Recurrent Erosion Dystrophy, Corneal Erosions

Instillation of Cacicol20 eye drops after laser corneal surgery. 3 eye drops total, to be given once immediately after surgery, once 2 days after surgery, and a final time 4 days after surgery.

Instillation of placebo eye drops (vehicle missing the active ingredient) after laser corneal surgery. 3 eye drops total, to be given once immediately after surgery, once 2 days after surgery, and a final time 4 days after surgery.

Investigational device, regenerating agent, single-use doses, topical eye drops. Indicated for corneal wound healing.

Degree of corneal subbasal nerve regeneration at one year postoperative, compared to preoperative level, as measured by clinical laser-scanning in vivo confocal microscopy.

Degree of corneal subbasal nerve regeneration at 6 months postoperative, compared to preoperative level, as measured by clinical laser-scanning in vivo confocal microscopy.

A drop of sodium fluorescein liquid is applied to the cornea, and a digital photograph is taken at high magnification with a clinical slit lamp biomicroscope, using a blue illumination lamp. Area of open wound is measured from photographs and expressed as a percentage of the total treated area.

Corneal haze measured microscopically by clinical in vivo confocal microscopy using a semi-quantitative grading scale.

Tear break up time (in seconds) timed by slit lamp biomicroscopic observation after instillation of sodium fluorescein and induction of blinking.

Distance corrected visual acuity improvement measured in Snellen lines gained/lost relative to preoperative level.

Defined as reactions or complications beyond those normally expected after laser corneal surgery. Assessed by the investigator.

Inclusion Criteria: Signed and dated informed consent, Male or female aged ≥ 18 years, Patient with recurrent erosions or epithelial dystrophies indicated for treatment by phototherapeutic keratectomy of the anterior cornea Exclusion Criteria: In the affected eye: prior corneal surgery In either eye: active ocular infection, glaucoma, or ocular hypertension General history judged by the investigator to be incompatible with the study (life-threatening patient condition). Known allergic hypersensitivity history to Poly(carboxyMethylGlucoseSulfate) or dextran. Inability of patient to understand the study procedures and thus inability to give informed consent. Participation in another clinical study within the last 3 months. Already included once in this study (can only be included for one treated eye) Specific exclusion criteria for women Known pregnancy (if uncertain pregnancy test will be performed) Lactation Women of childbearing potential without an effective method of contraception (oral contraceptive, intra-uterine device, subcutaneous contraceptive implant, vaginal ring) or women not hysterectomised, post-menopausal or surgically sterilized

Meddahi A, Alexakis C, Papy D, Caruelle JP, Barritault D. Heparin-like polymer improved healing of gastric and colic ulceration. J Biomed Mater Res. 2002 Jun 5;60(3):497-501. doi: 10.1002/jbm.1293.

Chebbi CK, Kichenin K, Amar N, Nourry H, Warnet JM, Barritault D, Baudouin C. [Pilot study of a new matrix therapy agent (RGTA OTR4120) in treatment-resistant corneal ulcers and corneal dystrophy]. J Fr Ophtalmol. 2008 May;31(5):465-71. doi: 10.1016/s0181-5512(08)72462-8. French.

Lagali N, Germundsson J, Fagerholm P. The role of Bowman's layer in corneal regeneration after phototherapeutic keratectomy: a prospective study using in vivo confocal microscopy. Invest Ophthalmol Vis Sci. 2009 Sep;50(9):4192-8. doi: 10.1167/iovs.09-3781. Epub 2009 Apr 30.

Germundsson J, Lagali N. Pathologically reduced subbasal nerve density in epithelial basement membrane dystrophy is unaltered by phototherapeutic keratectomy treatment. Invest Ophthalmol Vis Sci. 2014 Mar 25;55(3):1835-41. doi: 10.1167/iovs.13-12533.

Cejkova J, Olmiere C, Cejka C, Trosan P, Holan V. The healing of alkali-injured cornea is stimulated by a novel matrix regenerating agent (RGTA, CACICOL20): a biopolymer mimicking heparan sulfates reducing proteolytic, oxidative and nitrosative damage. Histol Histopathol. 2014 Apr;29(4):457-78. doi: 10.14670/HH-29.10.457. Epub 2013 Oct 9.

De Monchy I, Labbe A, Pogorzalek N, Gendron G, M'Garrech M, Kaswin G, Labetoulle M. [Management of herpes zoster neurotrophic ulcer using a new matrix therapy agent (RGTA): A case report]. J Fr Ophtalmol. 2012 Mar;35(3):187.e1-6. doi: 10.1016/j.jfo.2011.09.002. Epub 2011 Oct 19. French.

Kymionis GD, Liakopoulos DA, Grentzelos MA, Diakonis VF, Klados NE, Tsoulnaras KI, Tsilimbaris MK, Pallikaris IG. Combined topical application of a regenerative agent with a bandage contact lens for the treatment of persistent epithelial defects. Cornea. 2014 Aug;33(8):868-72. doi: 10.1097/ICO.0000000000000169.