Glaucoma Delivery Platforms Edge Closer to Commercialization

Existing glaucoma medications are highly effective—but more than half of patients miss doses, said Dr. Brandt. Sustained-release drugs could skirt the complications caused by noncompliance.

A declining role for eyedrops. Diverse delivery systems ranging from erodible pellets to drug-dispensing contact lenses are in development. “I think it’s safe to say that in a decade, we will be using eyedrops rarely,” said Dr. Brandt.

Implantable devices. He outlined a trifecta of implantable devices that are in, or approaching, phase 3 trials and expected to reach the market in about 3 to 5 years:

• Bimatoprost SR (Allergan), an erodible pellet injected into the anterior chamber as an in-office procedure, is likely to be the first sustained-release platform for glaucoma treatment. The pellet continuously delivers medication for 6 months, then degrades. The device demonstrated sustained reduction in intraocular pressure (IOP) in phase 2 trials and is currently in phase 3.
• iDose (Glaukos) is a titanium device that is surgically placed in the trabecular meshwork. It dispenses travoprost and must be replaced every 6 to 12 months. The company announced encouraging 1-year phase 2 findings in a press release, but peer-reviewed studies are not yet available.
• Travoprost XR–ENV 515 (Envisia Therapeutics) is a microfabricated erodible implant.

Early phase 2 data showed sustained IOP lowering out to 11 months (5 patients). The implants are created using a proprietary system, called PRINT technology The platform was recently acquired by Aerie Pharmaceuticals and will be used in conjunction with experimental therapy for retinal diseases. The implications for glaucoma are not yet clear.

External devices. Dr. Brandt also described a number of external devices that are expected to hit the market in the next few years:

• OTX-TP (Ocular Therapeutix) and Evolute (Mati Therapeutics) are punctal plugs designed to deliver prostaglandin analogs to the tear film for up to 3 months. OTX-TP is in phase 3 trials, while Evolute is in phase 2.
• The bimatoprost ring (Allergan) is a periocular ring inserted into the conjunctival cul-de-sac. It must be replaced by a clinician every 3 to 6 months once the drug is depleted. The ring has completed extensive phase 2 studies. Rings that dispense more than 1 drug have also been evaluated in small studies.

When these drug delivery devices come to market, glaucoma specialists should monitor patients carefully because the efficacy and duration of effect may vary from patient to patient.—Anni Griswold

Financial disclosures. James D. Brandt, MD: Allergan: S; National Eye Institute: S; Santen, Inc.: S.

Disclosure key. C = Consultant/Advisor; E = Employee; L = Speakers bureau; O = Equity owner; P = Patents/Royalty; S = Grant support.

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