NEWS & PERSPECTIVE

Novel micro-invasive injectable treatment for glaucoma receives FDA approval

15 Feb 2024

The travoprost intracameral implant has demonstrated non-inferiority towards topical timolol ophthalmic solution in reducing intraocular pressure (IOP) of patients with open-angle glaucoma (OAG) or ocular hypertension (OHT) in 2 phase 3 randomized controlled trial, which led to its approval from the United States (US) Food and Drug Administration (FDA) in December 2023, offering an alternate treatment option for patients with OAG or OHT.1,4

Glaucoma describes a group of progressive, degenerative optic neuropathies that are characterized by the loss of retinal ganglion cells and structural alterations of the optic nerve head and retinal nerve fiber layer.2 Since this disease is characterized by an increase in IOP, topical hypotensive medications and surgical interventions are the 2 conventional treatment approaches for managing IOP among patients with glaucoma.2 In particular, prostaglandin analogs are conventionally used as the first-line treatment due to their ability to reduce aqueous humor outflow resistance and facilitate outflow through the uveoscleral pathway.2

Nevertheless, the clinical efficacy of topical hypotensives is dependent on patients’ adherence to the regimen.2 Results from the Glaucoma Adherence and Persistence study projected a mean medication possessional ratio (MPR) of 0.64 for its study population (n=13,956), thereby highlighting the non-adherence among patients.2 Barriers to patient adherence to glaucoma medication regimens often included forgetfulness, difficulty in instilling eye drops, decreased self-efficacy, and difficulties with the medication schedule.2

In addition, topical hypotensives are often inefficient in practice.2 On average, 20% of a dosage of topical hypotensive was shown to be wasted due to suboptimal drug delivery by using more than one drop per dosing.2 Drug absorption has also been undesirable due to limitations with the small ocular surface area and the relative impermeability of the hydrophilic and lipophilic structures, ultimately resulting in roughly 1%-10% bioavalibility.2 Hence, significant research has been conducted on novel therapeutic drug delivery systems for the management of glaucoma in recent years.2

One notable example of such delivery systems is the travoprost intracameral implant, which is a microscopic titanium container that can be surgically anchored to the scleral wall of the anterior chamber, which provides sustained release of travoprost.3 A previously published phase 2 randomized controlled trial had found that the implant facilitated significant IOP reductions throughout the 36-month study period, regardless of elution rate (p<0.0001 for all).3 As such, 2 subsequent phase 3 randomized controlled trials, GC-010 and GC-012 were conducted to compare the clinical efficacy between this implant and 0.5% timolol maleate ophthalmic solution in reducing the IOP of patients with OAG or OHT.1

The phase 3 trials enrolled a total of 1,150 patients with OAG or OHT across 89 clinical sites.4 The study population was randomized to receive an intracameral implant containing 75mcg of travoprost (n=765), or 0.5% timolol ophthalmic solution (n=385).4 The primary efficacy endpoint of both studies was IOP reduction over the first 3 months.4 The safety profile was assessed through 12 months.4

At month 3, the travoprost intracameral implant demonstrated non-inferiority to timolol solution in IOP reduction.4 Mean IOP change from baseline for the implant was -6.6mmHg to -8.4mmHg, which was comparable to that of the timolol control group (-6.5mmHg to -7.7mmHg).4 Furthermore, the implant was well-tolerated among patients, with only 2%-6% of implant patients experiencing ocular adverse events such as iritis, dry eye, visual field defects, or IOP increase. 81% of implant subjects no longer required IOP-lowering topical medication at month 12.4 Thus, the travoprost intracameral implant demonstrated non-inferiority to timolol ophthalmic solution in IOP reduction during the first 3 months, thereby earning its approval from the FDA in December 2023.1,4

In summary, the travoprost intracameral implant has demonstrated notable efficacy and tolerable safety profile for FDA approval.1,4 With the advancement of topical drug delivery techniques, clinical obstacles such as patient adherence and suboptimal absorption rates can be addressed, thus favoring the prevention of disease progression and improvements in patients’ quality of life.2

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