PTAB

PGR2026-00015

Atossa Therapeutics Inc v. Jina Pharmaceuticals Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Endoxifen for the Treatment of Bipolar I Disorder
  • Brief Description: The ’997 patent discloses a method for treating bipolar I disorder by administering endoxifen citrate within a specific dose range (2-16 mg) and duration (up to 21 days). A key aspect of the claimed method is the negative limitation that it "does not include a rescue medication."

3. Grounds for Unpatentability

Ground 1: Lack of Written Description - Claims 1-10 are unpatentable under 35 U.S.C. §112

  • Prior Art Relied Upon: N/A (challenge is based on the specification's content).
  • Core Argument for this Ground:
    • Specification Mapping: Petitioner argued that the ’997 patent’s specification fails to provide adequate written description for the full scope of the issued claims. The specification allegedly lacks support for several key limitations that were added or relied upon during prosecution to overcome prior art.
    • Unsupported Limitations:
      • No Rescue Medication: The central limitation, "the method does not include a rescue medication," was construed during prosecution to mean the prospective and positive exclusion of such medications. Petitioner asserted the specification provides no support for this prohibitive meaning, instead only disclosing that a patient is "not required" to be administered one, which implies optionality, not exclusion.
      • Dose and Duration Ranges: The claims cover a dose range of 2-16 mg for "up to 21 days." Petitioner contended the specification fails to support these ranges, as it only describes a single 8 mg dose and consistently recites a treatment duration of "at least 21 days," a different and largely non-overlapping period.
      • Delayed Monitoring: Claims 6-10 require "monitoring the dose... no sooner than 21 days after commencement." Petitioner argued this limitation has no descriptive support or corresponding disclosure anywhere in the specification.

Ground 2: Lack of Enablement - Claims 1-10 are unpatentable under 35 U.S.C. §112

  • Prior Art Relied Upon: N/A (challenge is based on the specification's content).
  • Core Argument for this Ground:
    • Undue Experimentation: Petitioner argued that the ’997 patent does not enable a person of ordinary skill in the art (POSITA) to practice the full scope of the claims without undue experimentation. The specification provides only a single working example of an 8 mg dose and contains no data or guidance on how other doses within the claimed 2-16 mg range would achieve a "therapeutically effective concentration" while prohibiting rescue medication.
    • Unpredictable Art: Given the unpredictable nature of treating bipolar I disorder, Petitioner contended the patent offers a mere "research assignment" or "hunting license" to determine which of the hundreds of dose and duration combinations would be safe and effective across a broad patient population, especially when rescue medications are forbidden. The Wands factors, particularly the lack of guidance and working examples across the claimed scope, confirm non-enablement.

Ground 3: Anticipation by Ahmad 2016 - Claims 1-4 are anticipated under 35 U.S.C. §102

  • Prior Art Relied Upon: Ahmad 2016 (A. Ahmad et al., a 2016 clinical trial publication).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner asserted that if the limitation "does not include a rescue medication" is not construed as a prospective prohibition (the construction Petitioner argues lacks written description), then Ahmad 2016 anticipates claims 1-4. Ahmad 2016 discloses a clinical trial treating bipolar I disorder patients with 4 mg or 8 mg of endoxifen citrate in enteric-coated tablets for 21 days, which falls squarely within the claimed dose (2-16 mg) and duration ("up to 21 days") ranges.
    • Disclosure of the Negative Limitation: Although the Ahmad 2016 trial protocol permitted the use of benzodiazepines (a rescue medication) "as needed," Petitioner argued it expressly discloses the claimed method. The publication reports that at least 40 patients in the endoxifen treatment groups did not experience adverse psychiatric events and therefore did not receive any rescue medication, thus disclosing a method where rescue medication was not included for a subset of patients.

  • Additional Grounds: Petitioner also asserted that claims 6-10 are unpatentable as indefinite because the key limitation "monitoring the dose administered to the patient no sooner than 21 days after commencement" is ambiguous. The specification provides no definition or guidance as to what "monitoring" entails (e.g., plasma level testing, pill counts, patient interviews), leaving a POSITA unable to determine the scope of the claim with reasonable certainty.

4. Key Claim Construction Positions

  • "the method does not include a rescue medication" (Claims 1-10): This is the most critical disputed term. Petitioner argued that, based on the patent owner’s arguments to the Examiner to secure allowance, this phrase must be construed to mean the method positively excludes and prospectively prohibits the administration of any rescue medication at any time during the treatment course. This construction is central to Petitioner's argument that the claim lacks written description, as the specification allegedly never describes such a strict prohibition.

5. Key Technical Contentions (Beyond Claim Construction)

  • Contradiction of Factual Support: A central technical contention is that the ’997 patent’s sole working example is factually inaccurate and misleading. The patent describes a clinical trial where "no rescue medications were administered to any of the patients." However, Petitioner presented evidence from Ahmad 2020 (a later publication about the same study, co-authored by the patent's inventors) showing that rescue medications (lorazepam and diazepam) were in fact permitted and administered to patients in the study. This alleged contradiction undermines the entire evidentiary basis for the patentability of the claims, particularly the crucial "no rescue medication" limitation.

6. Relief Requested

  • Petitioner requests institution of post-grant review and cancellation of claims 1-10 of the ’997 patent as unpatentable.