Azurity Pharmaceuticals Inc v. Helsinn Healthcare SA

1. Case Identification

• Case #: IPR2025-00948
• Patent #: 9,943,515
• Petitioner(s): Azurity Pharmaceuticals, Inc.
• Patent Owner(s): Helsinn Healthcare S.A.
• Challenged Claims: 1-23

2. Patent Overview

• Title: Compositions and methods for treating centrally mediated nausea and vomiting
• Brief Description: The ’515 patent discloses methods for treating or preventing chemotherapy-induced nausea and vomiting (CINV) over multiple days using the neurokinin-1 (NK₁) antagonist netupitant. The methods involve administering netupitant in combination with other antiemetic agents like a 5-HT₃ antagonist (palonosetron) and a corticosteroid (dexamethasone).

3. Grounds for Unpatentability

Ground 1: Claims 11-17 and 19-23 are obvious over Herrstedt, Bös, and Herrington.

• Prior Art Relied Upon: Herrstedt (a 2007 journal article summarizing CINV treatments), Bös (Patent 6,297,375), and Herrington (a 2008 clinical study on aprepitant dosing).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that independent claim 11, which recites a single day-one administration of netupitant for treating CINV over five days, is an obvious modification of the prior art. Herrstedt taught the standard-of-care three-drug regimen for CINV (a 5-HT₃ antagonist, dexamethasone, and an NK₁ antagonist like aprepitant) effective for a five-day period. Bös disclosed netupitant as a new, potent, and selective NK₁ antagonist for treating emesis, making it an obvious substitute for the older aprepitant in Herrstedt's regimen. Finally, Herrington taught that a single, day-one dose of aprepitant was as effective as a multi-day dosing regimen for preventing CINV over five days, suggesting the same would hold true for the structurally similar netupitant.
  • Motivation to Combine: A person of ordinary skill in the art (POSA) would combine these references to improve the existing standard of care. The motivation was to substitute a known, improved NK₁ antagonist (netupitant from Bös) for an older one (aprepitant in Herrstedt) and to simplify the treatment regimen from multi-day to single-day dosing (as taught by Herrington) to improve patient compliance and ease of administration.
  • Expectation of Success: A POSA would have a reasonable expectation of success because netupitant belongs to the same class of drugs as aprepitant and operates via the same mechanism (NK₁ receptor antagonism). Herrington's demonstration of single-dose efficacy for aprepitant would lead to an expectation that netupitant, with its known long half-life, would be similarly effective. Dependent claims reciting specific dosages (e.g., 200-400mg, 300mg) were argued to be obvious optimizations within the broad effective range (10-1000mg) disclosed by Bös.

Ground 2: Claims 1-10 and 18 are obvious over Herrstedt, Bös, Hargreaves, and Herrington.

• Prior Art Relied Upon: Herrstedt (a 2007 journal article), Bös (Patent 6,297,375), Herrington (a 2008 clinical study), and Hargreaves (a 2002 journal article on NK₁ receptor occupancy).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground targets claims 1-10 and 18, which include limitations related to NK₁ receptor occupancy in the brain's striatum. The core combination of Herrstedt, Bös, and Herrington provides the same foundation as in Ground 1. Hargreaves was added to render the receptor occupancy limitations obvious. Hargreaves taught that a therapeutically effective dose of an NK₁ antagonist (aprepitant) for treating emesis correlates with at least 75% occupancy of NK₁ receptors in the striatum. Petitioner argued that the claimed limitations of occupying 70% or more (claim 1) or 80% or more (claim 2) of NK₁ receptors at 72 hours post-administration were inherent or obvious properties of administering a therapeutically effective dose of netupitant, as taught by the combination.
  • Motivation to Combine: The motivation was the same as in Ground 1, with the addition of using established scientific principles to guide dose selection. A POSA would have been motivated to consult a reference like Hargreaves, which links a measurable biomarker (receptor occupancy) to clinical efficacy, to confirm that the chosen dose of netupitant would be effective.
  • Expectation of Success: A POSA would expect success in achieving the claimed receptor occupancy because Hargreaves established a clear correlation between occupancy levels above 75% and antiemetic effects. A POSA would reasonably expect that a therapeutically effective dose of netupitant, selected by substituting it into the Herrstedt regimen, would naturally result in such occupancy levels. Petitioner noted that the patent examiner in a related case found these occupancy levels to be an inherent property of an effective netupitant dose.

4. Key Claim Construction Positions

• "therapeutically effective amount": Petitioner noted the patent's own definition means "an amount sufficient to elicit the desired biological response." This broad definition supports the argument that determining such an amount for netupitant would have been a routine optimization for a POSA.
• "which enters...": Petitioner argued that for claim element 1[b], the functions following the word "which" (e.g., crosses the blood-brain barrier, occupies receptors) describe inherent properties of a therapeutically effective amount, rather than additional therapeutic effects that would narrow the claim scope. This construction allows the prior art, which teaches an effective amount, to inherently meet these limitations.

5. Relief Requested

• Petitioner requests the institution of an inter partes review and the cancellation of claims 1-23 of Patent 9,943,515 as unpatentable under 35 U.S.C. §103.