PTAB

PGR2025-00040

AdVanCell Pty Ltd v. SCiencons As

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Radioisotope Generator
  • Brief Description: The ’437 patent describes a system and method for producing highly purified Lead-212 (²¹²Pb), a radioactive isotope used in targeted alpha therapy for cancer treatment. The claimed process isolates ²¹²Pb via a specific decay chain beginning with a solid Thorium-228 (²²⁸Th) precursor isotope source.

3. Grounds for Unpatentability

Ground 1: Anticipation by Hassfjell-Hoff - Claims 1, 3-4, 7-12, 14-19, 22-26, 28-29, 31-32, 34-36, and 38 are anticipated under 35 U.S.C. §102 by Hassfjell-Hoff.

  • Prior Art Relied Upon: Hassfjell-Hoff (a 1994 journal article titled “A Generator for Production of ²¹²Pb and ²¹²Bi”).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Hassfjell-Hoff discloses every limitation of the challenged claims. The reference describes a radioisotope generator with a solid precursor isotope source ([²²⁸Th]barium stearate) held in a movable basket. This source emanates a gaseous progeny isotope (²²⁰Rn), which decays to deposit a solid progeny isotope (²¹²Pb) onto a collector surface (the interior walls of a polyethylene bottle). The system uses a gate valve to selectively fluidly couple the source to the collection volume and employs O-rings and clamps to create a gas-tight seal, thereby anticipating the apparatus and method claims.

Ground 2: Anticipation by Norman - Claims 1, 3, 5-7, 15-16, 18, 20-22, 29-33, and 35-37 are anticipated under 35 U.S.C. §102 by Norman.

  • Prior Art Relied Upon: Norman (Patent 5,038,046).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Norman independently discloses all claimed elements. Norman describes a generator with two chambers: a first containing a solid precursor source (²²⁸Th dispersed in a porous matrix like graphite or ceramic) and a second collection chamber. A gaseous progeny (²²⁰Rn) diffuses from the first chamber into the second, where it decays and deposits solid progeny (²¹²Pb) on a collector surface. The entire generator is enclosed to prevent gas escape, thereby achieving a "gas tight seal," and a stopcock (valve) is disclosed to selectively couple the chambers.

Ground 3: Obviousness over Hassfjell-Hoff and Norman - Claims 1, 3-12, 14-26, and 28-38 are obvious under 35 U.S.C. §103 over Hassfjell-Hoff in view of Norman.

  • Prior Art Relied Upon: Hassfjell-Hoff (a 1994 journal article) and Norman (Patent 5,038,046).

  • Core Argument for this Ground:

    • Prior Art Mapping: The petition argued that to the extent Hassfjell-Hoff is found not to explicitly disclose certain features, such as a gas-tight seal around the collection chamber itself (as opposed to the overall system), Norman provides this teaching. Norman explicitly discloses sealing the collection chamber to prevent radon escape. Further, Norman teaches using alternative precursor materials, such as inert ceramics, which could be substituted for the barium stearate source in Hassfjell-Hoff.
    • Motivation to Combine: A POSITA would combine Norman’s teaching of a gas-tight seal on the collection chamber with the Hassfjell-Hoff generator to enhance worker safety and prevent radioactive contamination when handling the collection vessel, a known problem in the art. A POSITA would also be motivated to substitute Norman's ceramic precursor source for Hassfjell-Hoff's barium stearate source, as Norman teaches they are known alternatives for the same purpose.
    • Expectation of Success: A POSITA would have a high expectation of success, as the combination involves applying a known sealing technique and substituting a known alternative material to improve a known generator design, all within the same technical field.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including combinations of Hassfjell-Hoff with IAEA (a 2013 reference document) to add a flushing circuit (Claim 2), and with Westrøm (a 2017 journal article) to add the specific chelator TCMC (Claims 13 and 27). Further combinations involving Norman, Hassfjell-Hoff, and Westrøm were also presented.

4. Key Claim Construction Positions

  • “fluidly coupled” (claims 1, 16, etc.): Petitioner argued that since the specification does not recite this term but discloses parts connected via a gas, a POSITA would understand it to mean "capable of being connected or linked together using a gas."
  • “…configured to be fluidly coupled to a volume including a collector surface with a gas tight seal” (claim 1): Petitioner asserted this phrase is ambiguous and proposed three alternative constructions under which the claims are invalid:
    • The entire volume containing the source has a gas-tight seal.
    • The system is configured to selectively couple the source and the volume using a gas-tight seal (e.g., a valve).
    • Just the collector surface, not the entire volume, has a gas-tight seal.
  • The invalidity arguments were presented to address all three proposed constructions.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under §325(d) is unwarranted because the examiner committed clear and material error.
  • Although Hassfjell-Hoff and Norman were cited in an Information Disclosure Statement (IDS), they were never substantively evaluated during prosecution. The patent application was allowed without a single office action. The IDS containing these references was only filed after an initial Notice of Allowance, and the examiner’s subsequent Notice of Allowance repeated the same reasons for allowance without any mention or analysis of Hassfjell-Hoff or Norman, demonstrating they were overlooked.

6. Relief Requested

  • Petitioner requests institution of Post-Grant Review (PGR) and cancellation of claims 1-38 of the ’437 patent as unpatentable.