Vanda Pharma Inc v. MSN Pharma Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Vanda Pharmaceuticals Inc. (Delaware)
  • Defendant: MSN Pharmaceuticals Inc. (Delaware) and MSN Laboratories Private Limited (India)
  • Plaintiff’s Counsel: Morris, Nichols, Arsht & Tunnell LLP; Paul, Weiss, Rifkind, Wharton & Garrison LLP
• Case Identification: 1:19-cv-00926, D. Del., 05/17/2019
• Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant MSN Pharmaceuticals is incorporated in Delaware, and Defendant MSN Labs is an Indian corporation subject to personal jurisdiction in the district.
• Core Dispute: Plaintiff alleges that Defendants' filing of an Abbreviated New Drug Application (ANDA) to market a generic version of the drug tasimelteon constitutes an act of infringement of a patent covering a method for its use.
• Technical Context: The case involves a pharmaceutical treatment for Non-24-Hour Sleep-Wake Disorder, a serious circadian rhythm disorder that primarily affects totally blind individuals.
• Key Procedural History: The litigation was triggered by Defendants' filing of an ANDA with a Paragraph IV Certification for a generic version of Plaintiff's drug, HETLIOZ®. This certification asserts that Plaintiff's patent is invalid, unenforceable, or will not be infringed by the proposed generic product. The suit was filed within the 45-day statutory window following receipt of the Defendants' notice letter, which triggers a 30-month stay of FDA approval for the generic.

Case Timeline

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 10,149,829 - Treatment of Circadian Rhythm Disorders

The Invention Explained

• Problem Addressed: The patent addresses Non-24-Hour Sleep-Wake Disorder ("Non-24"), a condition where individuals, particularly those who are totally blind and lack light perception, are unable to synchronize their internal "master body clock" to a 24-hour day (’829 Patent, col. 1:52-2:2). This "free running" clock causes a patient's sleep cycle to drift later each day, leading to severe sleep and wakefulness disruptions (’829 Patent, col. 2:6-18).
• The Patented Solution: The invention is a specific method for safely treating circadian rhythm disorders with the drug tasimelteon in patients who are also taking another type of drug known as a "strong CYP1A2 inhibitor" (e.g., fluvoxamine) (’829 Patent, Abstract). Because these inhibitors can significantly increase a patient's exposure to tasimelteon, the patented method involves first reducing the dose of the CYP1A2 inhibitor and then treating the patient with tasimelteon, thereby reducing the risk of adverse reactions (’829 Patent, col. 8:41-48; col. 37:7-18).
• Technical Importance: The method provides a way to manage a potentially significant drug-drug interaction, which could allow for the safe and effective administration of tasimelteon to a patient population that may require concurrent treatment with other common medications (’829 Patent, col. 33:5-14).

Key Claims at a Glance

• The complaint asserts infringement of claims 1-14 (Compl. ¶52) and specifically provides the text of independent claim 1 (Compl. ¶41).
• Independent Claim 1:
  • A method of treating a patient for a circadian rhythm disorder or for a sleep disorder.
  • The patient is being treated with a strong CYP1A2 inhibitor (selected from fluvoxamine, ciprofloxacin, and verapamil).
  • The method comprises: (A) reducing the dose of the strong CYP1A2 inhibitor treatment and then (B) treating the patient with tasimelteon.
  • This method results in reduced exposure to tasimelteon.
• The complaint reserves the right to assert other claims, which may include dependent claims (Compl. ¶18, ¶55).

III. The Accused Instrumentality

Product Identification

• Defendants’ proposed generic tasimelteon oral capsules, 20 mg strength, for the treatment of Non-24, as described in ANDA No. 211654 ("MSN's ANDA Product") (Compl. ¶11).

Functionality and Market Context

• The infringement alleged is the statutory act of filing the ANDA seeking FDA approval to manufacture and sell a generic version of Plaintiff's HETLIOZ® product prior to the expiration of the ’829 Patent (Compl. ¶17). The complaint alleges that MSN's ANDA Product is intended for the same indication as HETLIOZ® (treatment of Non-24) and that its product labeling will essentially copy the FDA-approved HETLIOZ® label, as required by FDA regulations (Compl. ¶¶49, 52). The HETLIOZ® label is alleged to instruct physicians to "[a]void use of HETLIOZ in combination with fluvoxamine or other strong CYP1A2 inhibitors because of a potentially large increase in tasimelteon exposure and greater risk of adverse reactions" (Compl. ¶48).
• No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

’829 Patent Infringement Allegations

Identified Points of Contention:

• Scope Questions: A central dispute will be whether a label instruction to "avoid use" of two drugs in combination can be interpreted as an affirmative instruction to perform the claimed method of "reducing the dose" of one drug "and then" administering the other. Defendants may argue the label teaches away from the claimed method, while Plaintiff may argue that for a patient already on a CYP1A2 inhibitor, the only way to follow the "avoid use" instruction and still prescribe tasimelteon is to perform the claimed steps.
• Technical Questions: What evidence will be presented to show that a physician, when confronted with the label's warning to "avoid use," would be induced to reduce the CYP1A2 inhibitor dose rather than simply choosing not to prescribe tasimelteon? The question for the court will be whether the instruction makes the infringing use the only practical or intended one in this clinical scenario.

V. Key Claim Terms for Construction

• The Term: "reducing the dose of the strong CYP1A2 inhibitor treatment and then (B) treating the patient with tasimelteon"
• Context and Importance: This phrase constitutes the central, active steps of the claimed method. The entire inducement infringement theory hinges on whether the proposed product label instructs physicians to perform this specific sequence. Practitioners may focus on this term because its construction will determine whether a warning to "avoid" co-administration is sufficient to induce infringement.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A party might argue that the patent's overall objective is to manage a known drug interaction (’829 Patent, col. 33:5-14) and that any instruction that leads a physician to resolve this interaction by separating the administration of the two drugs falls within the claim's scope. The term should be read in the practical context of a physician's decision-making process.
  • Evidence for a Narrower Interpretation: A party might argue that the claim requires a specific, two-step affirmative action: first an act of "reducing the dose" (which could include stopping it entirely), followed by the act of "treating." The specification describes this as a distinct method (’829 Patent, col. 8:41-48), and an instruction to simply "avoid" the combination does not explicitly command this sequence and could be satisfied by not prescribing tasimelteon at all.

VI. Other Allegations

• Indirect Infringement: The complaint alleges that Defendants will induce infringement by physicians through the instructions on the proposed product label, which is expected to be substantially identical to the HETLIOZ® label (Compl. ¶52). It further alleges contributory infringement by asserting that the proposed generic product is not a staple article of commerce and has no substantial non-infringing uses (Compl. ¶53).
• Willful Infringement: The complaint alleges that Defendants had actual knowledge of the ’829 Patent, citing the Paragraph IV notice letter (Compl. ¶45). It further alleges that Defendants' assertions of invalidity and non-infringement are "devoid of an objective good faith basis" and requests that the case be declared "exceptional" to recover attorneys' fees under 35 U.S.C. § 285 (Compl. ¶60).

VII. Analyst’s Conclusion: Key Questions for the Case

• A core issue will be one of inducement: does a product label that warns physicians to "avoid" the combined use of two drugs induce infringement of a method claim that requires the sequential steps of "reducing" the dose of one and "then treating" with the other, or does it merely teach away from infringement?
• A key question of claim scope will be whether the specific sequence recited in Claim 1—"reducing the dose... and then... treating"—can be construed to cover a clinical scenario where a physician, guided by a general warning to "avoid" a drug combination, discontinues one drug before starting another.