PTAB

IPR2022-00123

Hope Medical Enterprises Inc v. OREGon Health & Science University

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method for Reducing Ototoxicity in Pediatric Patients Receiving Platinum-Based Chemotherapy
  • Brief Description: The ’190 patent is directed to a method for reducing hearing loss (ototoxicity) in pediatric cancer patients five years of age or younger. The method involves administering sodium thiosulfate (STS) approximately six hours after the patient receives platinum-based chemotherapy, such as cisplatin.

3. Grounds for Unpatentability

Ground 1: Obviousness over Freyer and Adherex - Claim 1 is obvious over the Freyer Presentation in view of the Adherex Press Release.

  • Prior Art Relied Upon: Freyer Presentation (a 2014 PowerPoint slide deck from an ASCO meeting) and Adherex Press Release (a 2014 press release from Fennec Pharmaceuticals).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the Freyer Presentation, which details the ACCL0431 clinical trial, discloses every limitation of claim 1. Freyer taught a method of administering STS (16 g/m²) six hours after cisplatin to pediatric patients (ages 1-18) to reduce ototoxicity. Crucially, Freyer presented data showing a statistically significant and pronounced reduction in hearing loss specifically for the subgroup of patients younger than five years old (21.4% with STS vs. 73.3% without). This data demonstrates the claimed "at least 50% better" reduction. Freyer also taught that STS did not negatively affect Event-Free Survival (EFS) or Overall Survival (OS) in patients with localized, non-metastatic tumors, meeting the survival limitation. The Adherex Press Release, which reported on the same ACCL0431 trial, corroborated Freyer’s findings and independently concluded that "STS protects against cisplatin-induced hearing loss in children, especially for those less than 5 years old."
    • Motivation to Combine: Petitioner asserted a Person of Ordinary Skill in the Art (POSITA) would combine these references because they are complementary and intertwined. Both references report the results of the same ACCL0431 clinical trial, with the Adherex Press Release quoting Dr. Freyer and Freyer acknowledging Adherex for supplying the STS. A POSITA would view the press release as a summary and confirmation of the more detailed clinical data presented in Freyer.
    • Expectation of Success: A POSITA would have a high expectation of success because both Freyer and Adherex explicitly conclude that the claimed regimen is effective at reducing hearing loss, particularly in the claimed patient population of children under five years old. The successful results were not theoretical but based on a completed Phase III clinical trial.

Ground 2: Obviousness over Brock, SIOPEL 6, and Adherex - Claim 1 is obvious over Brock as evidenced by the SIOPEL 6 Poster, in view of the Adherex Press Release.

  • Prior Art Relied Upon: Brock (a 2015 press release summarizing SIOPEL 6 trial results), SIOPEL 6 Poster (a 2015 ASCO poster), and Adherex Press Release (the same 2014 press release from Ground 1).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that this combination renders claim 1 obvious by directly addressing the Examiner’s stated reason for allowance. During prosecution, the Examiner allowed claim 1 over references like Brock because they did not explicitly teach the "surprising and unexpected" greater reduction in ototoxicity for patients under five. Petitioner contended that the Adherex Press Release, which was not before the Examiner, supplies this allegedly missing teaching. Brock and the SIOPEL 6 Poster disclose a method of administering STS (20 g/m²) six hours after cisplatin to treat standard-risk hepatoblastoma (a localized tumor) in a pediatric population with a median age of 12.8 months. The Adherex Press Release, in reporting on both the ACCL0431 and SIOPEL 6 trials, explicitly states the key conclusion that STS is particularly effective for children "less than 5 years old." This disclosure, made years before the patent's priority date, demonstrates the result was neither surprising nor unexpected.
    • Motivation to Combine: A POSITA would be motivated to combine these references as they are all directly related. Brock, the SIOPEL 6 Poster, and the Adherex Press Release all discuss the design, regimen, and results of the same SIOPEL 6 clinical trial. The references involve the same lead investigator (Dr. Brock) and the same supplier of STS (Adherex/Fennec). The Adherex Press Release further links the SIOPEL 6 results with the ACCL0431 results, encouraging a POSITA to consider the findings from both landmark studies together.
    • Expectation of Success: The combined references collectively teach that the claimed method is safe, does not compromise the anti-tumor efficacy of cisplatin, and is particularly effective in the claimed patient population. Given that the target population of the SIOPEL 6 trial (median age ~13 months) falls squarely within the "under 5" group, and Adherex explicitly highlights the efficacy for this group, a POSITA would reasonably expect success in applying the method.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under 35 U.S.C. § 325(d) would be inappropriate because the petition raises new issues that are materially different from those considered by the Examiner. The primary references relied upon, the Freyer Presentation and the Adherex Press Release, were never considered during prosecution. Petitioner asserted that these references directly contradict the Examiner's conclusion that the enhanced efficacy of STS in children under five was a surprising and unexpected result, which was the sole basis for allowance.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claim 1 of the ’190 patent as unpatentable.