PTAB

IPR2019-00448

Ocular Therapeutix v. Mati Therapeutics Inc

Key Events

Petition

petition

Title: Nasolacrimal Drainage System Implants for Drug Delivery
Brief Description: The ’082 patent relates to a drug delivery system for insertion into a patient's lacrimal canaliculus. The system comprises a cylindrical, rod-shaped body made of hydrogel polymers that contains a therapeutic agent and has a distinguishing color for visualization.

Prior Art Relied Upon: Pritchard (Application # 2005/0197614).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Pritchard disclosed every limitation of the challenged claims. Pritchard taught a drug delivery system for the lacrimal canaliculus comprising a cylindrical insert made of hydrogel polymers. Petitioner asserted that Pritchard also disclosed a "distinguishing color" by teaching a process that changes the insert material from clear to a "light straw color." Furthermore, Pritchard disclosed that the hydrogel inserts swell upon insertion, can comprise polymers with functional groups, and can deliver various therapeutic agents (including anti-glaucoma agents, corticosteroids, and antibiotics) to treat ophthalmic conditions. Petitioner noted that the ’082 patent appeared to have copied figures directly from Pritchard. The argument for claim 2 (lacking a "sheath body") was met by Pritchard’s disclosure of simple cylindrical hydrogel pieces without any layered structure.

Prior Art Relied Upon: Pritchard (Application # 2005/0197614) and Gillespie (Application # 2002/0169409).
Core Argument for this Ground:
- Prior Art Mapping: This ground was presented as an alternative in case Pritchard’s "light straw color" was deemed insufficient to teach the "distinguishing color" limitation. Petitioner asserted Pritchard taught all elements of the base drug delivery insert, while Gillespie explicitly addressed the problem of small, translucent punctum plugs being "very difficult to see." Gillespie taught making such plugs more easily visualized by adding a substance such as a dye or pigment to provide a saturated coloration that contrasts with surrounding tissue.
- Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Gillespie's explicit teaching on coloration with the canalicular inserts of Pritchard for the predictable purpose of making them easier to see. This would aid in verifying placement, locating the insert for removal, and detecting if it had become dislodged—a known problem with such devices.
- Expectation of Success: Adding a known colorant to a hydrogel-based medical device was a routine and well-understood practice, and a POSITA would have had a high expectation of success in doing so without affecting the device's primary function.

Prior Art Relied Upon: Pritchard (Application # 2005/0197614), Gillespie (Application # 2002/0169409), and Hellberg (Patent 6,646,001).
Core Argument for this Ground:
- Prior Art Mapping: This ground built upon the combination of Pritchard and Gillespie for the base colored drug-delivery insert and added Hellberg to teach the specific therapeutic agent, travoprost, required by dependent claims 8, 17, and 21. Petitioner argued Hellberg taught methods of treating glaucoma by administering a prostaglandin analog and specifically identified travoprost as one of its three "most preferred" analogs.
- Motivation to Combine: Pritchard taught using its inserts to treat glaucoma with anti-glaucoma agents, including prostaglandin analogs. A POSITA seeking to implement Pritchard's system for treating glaucoma would be motivated to select a known, effective, and preferred therapeutic agent for that purpose. Hellberg’s disclosure of travoprost as a "most preferred" prostaglandin analog would have provided a clear reason for its selection and inclusion in the drug delivery system of Pritchard and Gillespie.
Additional Grounds: Petitioner asserted additional obviousness challenges based on combining Pritchard with the *Handbook of Pharmaceutical Excipients* (for the color limitation) and Hellberg (for travoprost), relying on similar motivations to make the inserts more visible and to use a preferred therapeutic agent.

"distinguishing color to show": Petitioner proposed this term be construed as "color that improves visibility." This construction was central because this limitation was added during prosecution to overcome prior art rejections, and Petitioner argued that adding color for visibility was well-known in the art.
"sheath body": Petitioner proposed this term be construed as a "material or structure that is impermeable to the therapeutic agent and that covers a portion of a drug core to prevent migration of the therapeutic agent from the covered portion of the drug core." This construction was important for claim 2, which recites that the system does not comprise a sheath body, making a clear definition necessary to assess whether the prior art disclosed such a "sheathless" device.

Petitioner requests institution of an inter partes review and cancellation of claims 1-23 of the ’082 patent as unpatentable.