Merck Sharp & Dohme Corp v. Microspherix LLC

1. Case Identification

• Case #: IPR2018-01288
• Patent #: 6,514,193
• Filed: June 18, 2018
• Petitioner(s): Merck Sharp & Dohme Corp., Merck Sharp & Dohme B.V., and Organon USA, Inc.
• Patent Owner(s): Microspherix LLC
• Challenged Claims: 1-2

2. Patent Overview

• Title: Method of Administering a Drug Via Implantable Seed
• Brief Description: The ’193 patent discloses a method for administering a non-radioactive drug by implanting a "brachytherapy seed" that contains the drug and a radiopaque marker. The seed is delivered to a target tissue using a brachytherapy implantation needle to allow for localized drug delivery and visualization of the implant.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-2 by Crittenden

• Prior Art Relied Upon: Crittenden (Patent 6,197,324).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Crittenden anticipates every limitation of claims 1 and 2. Crittenden was shown to teach methods for implanting a depot ("seed") into a tissue wall to deliver a therapeutic agent. This seed is described as a solid pellet formed from a non-metal, biocompatible, and biodegradable polymer. The pellet is "doped or 'seeded'" with a non-radioactive drug and includes a radiopaque marker (e.g., a gold or platinum core) to aid visualization by X-ray. Furthermore, Crittenden discloses a "needle-like" delivery chamber for implanting these pellets, which Petitioner asserted meets all limitations of the claimed brachytherapy implantation instrument and its use.

Ground 2: Obviousness of Claims 1-2 over Zamora in view of Grimm

• Prior Art Relied Upon: Zamora (Patent 6,575,888) and Grimm (Patent 5,938,583).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Zamora discloses all elements of the claimed seed, including a bioabsorbable, polymeric "brachytherapy device" containing a non-radioactive therapeutic drug and a radiopaque medium. However, Zamora does not expressly describe a specific implantation instrument. To supply this element, Petitioner pointed to Grimm, which teaches a conventional brachytherapy implantation instrument and needle combination for implanting seeds to treat prostate cancer.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine these references because Zamora explicitly states its seeds are to be implanted in a "conventional manner." Grimm teaches such a conventional and well-known method and device, which the ’193 patent itself acknowledges was known in the art. Therefore, a POSA would have naturally looked to a device like Grimm's to implant Zamora's seeds.
  • Expectation of Success: A POSA would have a reasonable expectation of success in combining the teachings, as Zamora's seeds were designed for implantation via conventional methods and instruments like those disclosed in Grimm.

Ground 3: Obviousness of Claim 1 over De Nijs in view of Schopflin and Mascarenhas 1998

• Prior Art Relied Upon: De Nijs (Patent 5,150,718), Schopflin (Patent 4,012,497), and Mascarenhas 1998 (a journal article).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground leveraged the Patent Owner's broad claim construction from related litigation, under which "brachytherapy seed" was argued to encompass non-radioactive contraceptive implants. Petitioner argued De Nijs teaches a cylindrical polymer implant for delivering a contraceptive hormone. Schopflin teaches the benefit of adding a radiopaque marker, such as barium sulfate, to similar polymer implants to improve X-ray localization. Finally, Mascarenhas 1998 discloses a specific needle-based applicator designed to implant the Implanon® rod, a device Petitioner asserted is identical in construction and dimension to the implant described in De Nijs.
  • Motivation to Combine: A POSA would combine De Nijs and Schopflin to add a radiopaque marker to an implant, solving the known clinical problem of locating non-palpable implants for removal. A POSA would then use the Mascarenhas applicator because it was specifically designed for the De Nijs-type implant, making the combination of all three references a straightforward solution for creating a trackable, implantable contraceptive device.
  • Expectation of Success: High, as all references operate in the same field of polymer drug-eluting implants and address complementary, well-understood functionalities with overlapping technical features.
• Additional Grounds: Petitioner asserted an additional obviousness challenge against claims 1-2 based on Crittenden in view of the ’008 patent (Patent 5,629,008), arguing that even if Crittenden did not anticipate the claims, it rendered them obvious.

4. Key Claim Construction Positions

• For the purposes of this IPR, Petitioner adopted the Patent Owner's broad claim constructions from parallel district court litigation, a position that was critical to the viability of Ground 3.
• "Brachytherapy" limitations: Petitioner argued these terms, consistent with the Patent Owner’s position, should be construed as names for the claimed objects and do not require the use of radioactive materials.
• "Target tissue" limitations: Petitioner likewise adopted the Patent Owner's position that this term does not require the implantation site to be the same as the drug's site of action, thereby encompassing contraceptive implants placed in an arm for systemic effect.

5. Key Technical Contentions (Beyond Claim Construction)

• Validity of Zamora as Prior Art: A significant portion of the petition was dedicated to preemptively arguing that Zamora is valid prior art under pre-AIA 35 U.S.C. §102(e). Petitioner asserted that Zamora is entitled to the earlier filing date of its provisional application because the claims of the Zamora patent are fully supported by the provisional’s disclosure. This technical-legal argument was central to establishing the patent-defeating effect of Zamora as asserted in Ground 2.

6. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial would be inappropriate because the asserted grounds were not cumulative and relied on prior art not considered during the original prosecution of the ’193 patent. It was noted that Crittenden and Schopflin were never cited during any related prosecution. While other references were cited in related applications, none of the proposed grounds were previously considered during prosecution of the ’193 patent itself, weighing against denial under §325(d).

7. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-2 of the ’193 patent as unpatentable under 35 U.S.C. §§ 102 and 103.