In a swift resolution spanning just 84 days, Merck Sharp & Dohme, LLC and Azurity Pharmaceuticals, Inc. jointly stipulated to dismiss without prejudice all claims and counterclaims in Case No. 1:24-cv-00545, filed in the Delaware District Court before Chief Judge Richard G. Andrews. The dispute centered on U.S. Patent No. 7,326,708 B2, covering technology relevant to JANUVIA® (sitagliptin), Merck’s blockbuster type 2 diabetes medication, in response to Azurity’s pursuit of a generic equivalent. The mutual dismissal, filed under Federal Rule of Civil Procedure 41(a)(1)(A)(ii), leaves all parties bearing their own costs and attorneys’ fees.

This case exemplifies the dynamic and often unpredictable nature of Hatch-Waxman pharmaceutical patent litigation, where early settlement or strategic withdrawal can signal licensing negotiations, formulation pivots, or shifting commercial priorities. IP counsel monitoring the generic drug landscape, in-house teams managing branded pharmaceutical portfolios, and R&D leaders developing competing formulations should carefully consider what this dismissal signals about the enforceability of Merck’s sitagliptin patent estate and Azurity’s generic development strategy.

Case Overview

The Parties

The Patent at Issue

U.S. Patent No. 7,326,708 B2 (Application No. US10/874,992) covers chemical compositions and formulations relating to sitagliptin, the active pharmaceutical ingredient in JANUVIA®, a widely prescribed oral medication for managing type 2 diabetes. The patent protects specific compound structures or formulation methods that Merck claims are infringed by Azurity’s proposed generic product. In practical terms, this patent serves as a key component of Merck’s exclusivity wall around JANUVIA®, a medication with multi-billion dollar annual revenues.

• • US7326708B2

Legal Representation

Plaintiff Counsel: McCarter & English LLP (lead: Alexandra M. Joyce)
Defendant Counsel: Potter Anderson & Corroon, LLP (lead: Bindu Ann George Palapura)

Litigation Timeline & Procedural History

This case was filed on May 3, 2024, in the U.S. District Court for the District of Delaware — the preeminent venue for Hatch-Waxman pharmaceutical patent litigation, chosen by branded drug companies for its specialized judiciary, procedural efficiency, and well-developed case law on ANDA-related disputes. Chief Judge Richard G. Andrews, an experienced jurist with a substantial pharmaceutical patent docket, presided over the matter at the first-instance district court level, meaning no appellate review was sought or issued in this proceeding.

The case closed on July 26, 2024 — just 84 days after filing — a remarkably compressed timeline that strongly suggests the parties reached a resolution or strategic agreement well before any substantive motion practice or claim construction proceedings could occur. The termination via a joint Rule 41(a)(1)(A)(ii) stipulation of dismissal without prejudice is a hallmark of either an out-of-court licensing agreement, a consent settlement with deferred terms, or a tactical withdrawal pending reformulation. The without-prejudice designation is particularly noteworthy: it preserves Merck’s right to re-file the same infringement claims if circumstances change, such as a future ANDA approval or commercial launch by Azurity.

The Verdict & Legal Analysis

Outcome

The case was dismissed without prejudice pursuant to a joint stipulation under Federal Rule of Civil Procedure 41(a)(1)(A)(ii), meaning neither party obtained a court judgment on the merits of the patent infringement claims or any counterclaims asserted by Azurity. No damages were awarded, no injunctive relief was issued, and no claim construction rulings were made. Each party was ordered to bear its own costs, disbursements, and attorneys’ fees, reflecting a mutually negotiated exit from the litigation.

Verdict Cause Analysis

The infringement action was resolved procedurally rather than substantively, but several legal and strategic factors likely drove the parties’ joint decision to dismiss:

• The filing of a joint stipulation under Rule 41(a)(1)(A)(ii) requires consent from all parties, indicating that both Merck and Azurity affirmatively agreed to exit the litigation — strongly implying a negotiated resolution such as a licensing agreement, market entry date settlement, or regulatory milestone trigger.
• The dismissal was entered without prejudice, which preserves Merck’s ability to re-assert U.S. Patent No. 7,326,708 B2 against Azurity if the generic product is commercially launched or if ANDA approval occurs outside agreed parameters — a common structure in Hatch-Waxman consent settlements.
• The 84-day duration from filing to dismissal precedes any typical Hatch-Waxman 30-month stay expiration, suggesting the parties resolved the dispute on commercial terms rather than allowing the litigation to run its statutory course.
• Each party bearing its own fees is consistent with a negotiated settlement rather than a litigation victory, as fee-shifting under 35 U.S.C. § 285 in exceptional cases would typically apply only after substantive adjudication.

Legal Significance

1. 1. The dismissal without prejudice sets no precedent on the validity or infringement scope of U.S. Patent No. 7,326,708 B2, leaving the patent’s enforceability intact and available for Merck to assert against other generic filers seeking to market sitagliptin products.
2. 2. For other ANDA applicants referencing JANUVIA®, this outcome provides no claim construction guidance or invalidity findings that could be leveraged in parallel or future Hatch-Waxman litigations — each future challenger must litigate the patent on fresh grounds.
3. 3. The rapid resolution underscores a broader trend in Delaware pharmaceutical patent litigation where early commercial settlements, often involving authorized generic agreements or negotiated market entry dates, resolve disputes before any judicial ruling on the merits.

Strategic Takeaways

For Patent Attorneys:

• When advising generic pharmaceutical clients, model the strategic value of a Rule 41(a)(1)(A)(ii) joint dismissal as a negotiating outcome — it preserves flexibility for both parties and avoids the risk of adverse claim construction rulings that could affect the broader patent estate.
• The without-prejudice dismissal here means Merck retains full enforcement rights against Azurity; draft any settlement or consent judgment carefully to ensure that market entry conditions, authorized generic provisions, and re-filing triggers are unambiguously defined.
• Monitor Azurity’s ANDA progress with the FDA independently of this dismissal — if approval is granted and commercial launch is attempted outside any agreed parameters, Merck’s preserved right to re-file creates immediate litigation exposure for Azurity.
• In Hatch-Waxman cases resolved this quickly, counsel should ensure that any side agreement accompanying the stipulation complies with antitrust review requirements under the FTC’s reverse payment settlement framework established in FTC v. Actavis.

For IP Professionals:

• In-house teams at branded pharmaceutical companies should treat the dismissal without prejudice as a living enforcement asset — document the triggering conditions under which re-filing is warranted and build monitoring protocols around Azurity’s regulatory filings and commercial launch signals.
• Portfolio managers tracking sitagliptin patent expiry and lifecycle management should note that U.S. Patent No. 7,326,708 B2 remains a live assertion vehicle; cross-reference it against the full Orange Book listing for JANUVIA® to assess remaining exclusivity runway against additional generic challengers.

For R&D Teams:

• R&D and formulation teams at companies developing DPP-4 inhibitor generics or sitagliptin-based combination products should not interpret this dismissal as a clearance event — U.S. Patent No. 7,326,708 B2 remains enforceable and Merck retains the right to assert it against any ANDA filer.
• Consider commissioning a comprehensive freedom-to-operate analysis against Merck’s full sitagliptin patent family before advancing any generic or follow-on formulation into IND-enabling studies, as the compound and formulation claims in this patent estate may cover a broader range of dosage forms than the original JANUVIA® tablet.