Joshua Mali, MD, focuses his blog on individualized patient care in a private retina practice setting.

BLOG: Top five things to know about an innovative drug delivery system for DME

Standard therapy for the rising number of patients with diabetic macular edema typically consists of anti-VEGF treatments. However, a significant number of patients continue to suffer with persistent DME due to the involvement of pro-inflammatory factors. For these patients, corticosteroids can be a valuable and effective treatment modality.

Therefore, a drug delivery system that provides the continuous therapy these patients require without adding to their treatment burden, such as the one in Iluvien (fluocinolone acetonide, Alimera Sciences), is highly beneficial to optimize patient outcomes. A truly long-term, effective, sustained-release delivery system is a game-changing innovation that offers several advantages over previous options.

A unique delivery system

A drug’s delivery system is an important consideration as it ensures the desired concentration is delivered to the correct target area. Topical drops are notoriously difficult to administer and, even delivered successfully, must still make their way past the anterior segment to where they are needed more posteriorly. Drugs such as triamcinolone can be injected into the correct target area but must be injected frequently to achieve continued efficacy.

Sustained-release medications allow for continuous treatment without the burden of multiple injections. Iluvien’s implant is a non-biodegradable cylindrical polymer tube that measures 3.5 mm in length and 0.37 mm in diameter. The implant containing the fluocinolone acetonide is placed into the vitreous cavity through a 25-gauge needle. The drug then diffuses through the tube, delivering a consistent, sustained release of fluocinolone acetonide for up to 3 years. Unlike other sustained-release options that dissolve after a few months, Iluvien provides long-term, continuous microdosing that has a proven track record of safety and efficacy.

The right drug

There are several commonly used ocular steroids that are all slightly different in chemical composition and efficacy levels. In addition to delivery method, they can also be differentiated by drug penetration. A drug’s water solubility determines how well it will be absorbed by the retinal tissue. A highly water-soluble drug, such as dexamethasone, does not penetrate tissue well and therefore requires higher doses to achieve its efficacy. Fluocinolone acetonide, however, is a synthetic fluorinated corticosteroid with low aqueous solubility, making it lipophilic. This allows it to better penetrate the tissues of the retina, thereby achieving high levels of clinical efficacy from low doses.