We are a clinical-stage drug delivery technology company focused on our patented “pack & release” nano-layered platform that delivers ophthalmic drugs to the eye to more effectively treat chronic conditions such as glaucoma and dry eye syndrome.
EXP-LP
Glaucoma is the second most common cause of blindness in the world, with almost 70 million people suffering from glaucoma today. Glaucoma is caused by a blockage of the eye’s drainage pathway, leading to a buildup of the fluid (aqueous humour) that normally flows through the eye and an increase in interocular pressure (IOP). This increased pressure in the eye often occurs without pain or visible warning signs until damage to the optic nerve has already occurred, leading to decreased vision and even blindness. (Fang et al., 2008).
The current pharmacological approach to lowering IOP for glaucoma patients is topical administration of eye drops. These eye drops work from two main mechanisms of action: either increasing aqueous humor outflow (e.g., prostaglandin agonists, cholinergics) or suppression of aqueous humor production (e.g., beta-blockers, alpha agonists and carbonic anhydrase inhibitors). Several challenges exist with the administration and efficacy of eye drops, including patient compliance, overuse, and risk of complications from preservatives contained in eye drops.
Current surgical therapies also seek to lower IOP by either decreasing aqueous humor production (e.g., cyclcophotocoagulation) or modifying the trabecular meshwork to decrease outflow resistance and increasing aqueous outflow (e.g., selective laser trabeculoplasty, trabeculectomy, glaucoma drainage implants, and glaucoma shunts). Although surgical and laser procedures address the compliance and adherence problems of eye drops, they are invasive procedures that are prone to infection and complications due to tissue damage, and efficacy in lowering IOP is still controversial.
Therefore, there is a need to combine the safe and efficacious properties of eye drops and the improved compliance of surgical procedures while eliminated the downside risks and reduced efficacy of both approaches.
In addition to improving compliance over medications that are dependent upon successful and timely patient self-administration of eye drops, EXP-LP provides a steady micro-dose of latanoprost to the eye, avoiding the oscillations in drug level experienced with eye drops. Additionally, continuous drug delivery via EXP-LP in the therapeutic window improves clinical outcomes.
EXP-TC
Dry eye syndrome (DES) is one of the most frequently encountered eye conditions seen by eye care practitioners. 25% of patients who visit ophthalmic clinics report symptoms of dry eye and the prevalence of DES is estimated to be 7.4% to 33.7%, making it a growing public health problem.
DES has two distinct components: insufficient tear production and tear evaporation. Insufficient tear production is caused by Sjögren’s Syndrome, an autoimmune disease that attacks the lacrimal (tear) gland. Tear evaporation is caused by insufficient lipid production by the Meibomian gland, lipids that constitute the top layer of the tear film. Whatever the cause, there is almost always a component of inflammation and increased osmolarity on the ocular surface which causes the common symptoms of itchiness, redness, burning sensation, dryness and sensitivity to light.
The first-line therapy for DES is external augmentation of the tear film with topically administered artificial tear substitutes. Currently, there are numerous formulations on the market attempting to enhance tear film stability; however, many have been found to only temporarily relieve the symptoms of dry eye rather than to heal the ocular surface or treat the underlying cause of the disease.
Another approach to treat DES is the insertion into the tear canal of a small device called a punctal plug made from collagen or silicone. The punctal plug physically blocks tear drainage, resulting in increasing tear quantity. There are numerus designs and shapes of approved punctal plugs on the market with excellent safety records. The weakness of plugs is that they only improve tear volume and do not treat the inflammatory component of DES. In fact, plugs might exacerbate the inflammation because they block the drainage of inflammatory agents such as cytokines, thereby artificially increasing their concentration in the eye.
Because chronic inflammation plays an important role in DES, treatment with topical corticosteroids (in the form of eyedrops) has been demonstrated to ameliorate the signs and symptoms of the disease. Although these agents have proven short-term efficacy, their long-term use may cause intraocular pressure elevation and cataract progression. A safer alternative to corticosteroids is a family of drugs called calcineurin inhibitors. Their anti-inflammatory mechanism is different than corticosteroids, as they act by inhibiting the activation of T-lymphocutes. The most common representative of this family is cyclosporin, which is sold in the US as eyedrops under the brand name of Restasis®.
The disadvantage of cyclosporin eyedrops is the poor patient compliance, leading to suboptimal treatment. Since DES is a chronic and progressive disease, neglecting to treat it properly might result in irreversible damage to the ocular surface.
Roberts et al.* showed that a combination therapy of plugs and cyclosporin eyedrops is superior to each treatment alone. Today, this combination therapy consists of two separate and distinct treatments: a plug inserted in the tear canal and patient administration of eyedrops. EXP-TC is a combination product, as a calcineurin inhibitor medication is manufactured as part of the punctal plug itself. As such, EXP-TC provides both a mechanical block to increase tear volume (i.e., the punctal plug) and a pharmaceutical anti-inflammatory medication to treat the underlying cause of DES (i.e., calcineurin inhibitor). This novel combination in the form of EXP-TC overcomes the compliance issues associated with eye drops by ensuring constant supply of drug for the duration of three months.
*Roberts CW, Comparison of Topical Cyclosporine, Punctal Occlusion, and a Combination for the Treatment of Dry Eye, Cornea. 2007 Aug;26(7):805-9.
In vitro studies of EXP-TP established that the novel punctal plug can deliver a controllable release of drug at an optimal therapeutic rate. Specifically, the amount of drug released by the plug over a 60-day period was above the minimum required threshold of 0.6 µg/day.
In vivo studies of EXP-TP against both an active and a placebo control in a DES induced animal model showed no difference in overall health. Further, the EXP-TC treated eyes showed EXP-TC was even more effective in protecting the cornea from damage than the active control.
