Strongbridge Dublin v. USPTO: Federal Circuit Splits Decision on Dichlorphenamide Patent
Strongbridge Dublin Ltd. challenged the USPTO before the Federal Circuit over patent application US17/675660, covering methods of treating disease with dichlorphenamide. After 567 days of appellate proceedings, the court issued a mixed ruling — affirming in part, vacating in part, and remanding — leaving the patent’s fate partially unresolved.
Federal Circuit issues split ruling on dichlorphenamide treatment patent appeal
In case 23-2303, Strongbridge Dublin Ltd. petitioned the United States Court of Appeals for the Federal Circuit to challenge decisions by the USPTO — represented by Acting Director Derrick Brent — relating to patent application US17/675660. The application claims methods of treating disease with dichlorphenamide, a carbonic anhydrase inhibitor with established uses in periodic paralysis and related conditions. The appeal was filed on 21 August 2023 and adjudicated over 567 days.
The Federal Circuit issued a nuanced mixed decision: affirming certain USPTO determinations, vacating others, and remanding the contested issues back to the USPTO for further consideration. The partial dismissal of the appeal suggests procedural barriers prevented full merits review on some claims, while the vacatur on remaining issues signals the court found at least one reversible error in the USPTO’s analysis below.
A 567-day appellate timeline is broadly consistent with contested Federal Circuit pharmaceutical patent appeals. The split disposition — affirm, vacate, remand — is notable because it neither fully vindicates Strongbridge’s position nor definitively forecloses patent protection. The public record does not disclose which specific claims or rejections were affirmed versus vacated, leaving the precise scope of any surviving patent protection subject to further USPTO proceedings on remand.
Filing to Appeal Dismissed in Part in 567 days
567 days from filing to Federal Circuit decision — typical for complex pharma patent appeals
Federal Circuit affirms in part and vacates in part: what the split ruling means
What ‘Affirmed-in-Part, Vacated-in-Part, Remanded’ means
A split Federal Circuit disposition means the court reviewed the USPTO’s decision on multiple grounds and reached different conclusions on each. Where affirmed, the court found no reversible error — those USPTO determinations stand. Where vacated, the court found the agency’s reasoning legally insufficient or erroneous, nullifying that portion. Remand directs the USPTO to re-examine the vacated issues under corrected legal standards, meaning proceedings continue below.
Mixed appellate outcomeStrongbridge wins partial relief — remand opens path to prosecution
For Strongbridge Dublin, the vacatur and remand represent a meaningful partial victory. At least one USPTO rejection has been set aside, requiring the agency to reconsider under guidance from the Federal Circuit. However, the affirmed portion confirms that some USPTO determinations are final and cannot be reopened on the same grounds. Strongbridge must now prosecute surviving claims before the USPTO, with the outcome of remand remaining uncertain.
Partial win — remand continuesUSPTO must revisit vacated rejections under court’s direction
The USPTO, having had portions of its decision vacated, must re-examine the relevant patent claims on remand. The affirmed portions confirm the agency’s position on those grounds is legally sound. The partial dismissal of the appeal suggests certain issues were not properly before the Federal Circuit — a procedural outcome that typically limits the scope of review without addressing the underlying merits.
Remand to USPTODichlorphenamide IP landscape remains unsettled pending remand
For pharmaceutical companies operating in the carbonic anhydrase inhibitor and periodic paralysis treatment space, this split ruling suggests continued uncertainty around dichlorphenamide method-of-treatment patent rights. Competitors and generic developers should monitor USPTO remand proceedings closely. The Federal Circuit’s partial vacatur may signal a narrowing or refinement of allowable claim scope, which could affect freedom-to-operate assessments across the therapeutic category.
IP uncertainty — monitor remandFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | In re: STRONGBRIDGE DUBLIN LTD. | Company | Pharmaceutical company — holder of patent application US17/675660 covering dichlorphenamide treatment methodsSearch in Eureka ↗ |
| Defendant | DERRICK BRENT, Acting Under Secretary of Commerce for Intellectual Property and Acting Director of the United States Patent and Trademark Office | Individual | Acting Director of the USPTO, representing the federal agency’s examination and appeal decisionsSearch in Eureka ↗ |
| Plaintiff counsel | Deborah Sterling | Attorney | Counsel for In re: STRONGBRIDGE DUBLIN LTD.Search in Eureka ↗ |
| Plaintiff law firm | Sterne, Kessler, Goldstein & Fox, PLLC | Law Firm | Representing In re: STRONGBRIDGE DUBLIN LTD.Search in Eureka ↗ |
| Defendant counsel | Thomas W. Krause | Attorney | Counsel for DERRICK BRENT, Acting Under Secretary of Commerce for Intellectual Property and Acting Director of the United States Patent and Trademark OfficeSearch in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | Court of Appeals for the Federal CircuitSearch in Eureka ↗ |
Official order — verbatim text
The Federal Circuit’s disposition — ‘Affirmed-in-Part, Vacated-in-Part, and Remanded’ — reflects a granular review of multiple USPTO determinations rather than a binary win or loss. Affirmance signals the court applied the deferential APA standard and found substantial evidence supporting those agency grounds. Vacatur of other grounds indicates legal error — likely in the USPTO’s application of patentability doctrine — necessitating agency reconsideration. The partial dismissal indicates at least one issue lacked the procedural prerequisites for appellate review. Taken together, the ruling is inconclusive on ultimate patentability.
US17/675660 — Methods of Treating Disease with Dichlorphenamide
US17/675660 is a patent application filed by Strongbridge Dublin Ltd. claiming methods of treating disease using dichlorphenamide, a carbonic anhydrase inhibitor with established clinical use in primary periodic paralysis. The application focuses on treatment method claims — a category that, if granted, would cover clinical protocols and potentially limit generic and biosimilar entrants from offering identical therapeutic regimens. Method-of-treatment patents in specialty pharma often survive challenges to compound patents, making prosecution strategy critical.
Dichlorphenamide occupies a narrow but commercially significant niche: it is one of few FDA-approved agents for periodic paralysis, a rare neuromuscular condition. Method-of-treatment patent protection in rare disease categories can have outsized commercial impact relative to patient population size, given high treatment costs and limited therapeutic alternatives. Competitors in the rare neuromuscular disease space — including generic manufacturers — should monitor the outcome of USPTO remand proceedings, as allowable claim scope will determine the enforceability horizon.
Should you run an FTO analysis against US17/675660?
Any company developing, manufacturing, or commercialising dichlorphenamide-based therapies or treatment protocols for periodic paralysis or related diseases should assess freedom-to-operate against US17/675660. Because the patent application remains in active prosecution following remand, the scope of any claims that may ultimately issue is not yet fixed. Generic pharmaceutical developers, specialty pharma licensees, and clinical-stage rare disease programmes should treat this as a live risk until USPTO proceedings conclude.
PatSnap Eureka’s FTO Search Agent allows R&D and IP teams to monitor US17/675660 prosecution history in real time, mapping pending claims against product pipelines and flagging scope changes as they occur on remand. Eureka’s claim analysis tools can identify design-around opportunities and assess whether treatment method variations fall within or outside anticipated claim language — enabling proactive clearance strategy rather than reactive responses to grant.
Run a freedom-to-operate analysis on US20220168249A1 to assess your product’s exposure
Run FTO in Eureka →Similar Federal Circuit appeals: pharmaceutical method-of-treatment patent disputes
Explore Federal Circuit cases involving USPTO appeals over pharmaceutical method-of-treatment patents, including carbonic anhydrase inhibitor and rare disease therapeutics.
What this case signals for the pharmaceutical patent prosecution landscape
Split Federal Circuit rulings in USPTO appeals are increasingly common in specialty pharma — and each component carries distinct strategic weight.
Partial vacatur at the Federal Circuit is not a full win — track remand outcomes
When the Federal Circuit vacates only part of a USPTO decision, patent applicants retain the burden of persuading the agency on remand. Companies monitoring Strongbridge’s dichlorphenamide portfolio should track USPTO remand proceedings to assess whether allowable claims emerge and what scope they ultimately cover.
Partial appeal dismissal signals a procedural threshold was not met on some issues
The partial dismissal component of this ruling suggests certain rejections or claims were not properly appealable to the Federal Circuit — possibly due to finality, standing, or jurisdictional requirements. IP teams challenging USPTO decisions should assess procedural readiness before filing to avoid losing appellate review on key grounds.
In v DERRICK — key questions answered
The Federal Circuit issued a split decision: affirming certain USPTO determinations regarding patent application US17/675660, vacating others, and remanding the vacated issues back to the USPTO for further proceedings. The appeal was also dismissed in part on procedural grounds. No final patentability determination was reached on the vacated claims.
The case concerns US patent application US17/675660, which claims methods of treating disease with dichlorphenamide, a carbonic anhydrase inhibitor used clinically in primary periodic paralysis. The application was before the Federal Circuit following USPTO rejection proceedings.
When the Federal Circuit vacates a USPTO decision and remands, it nullifies the agency’s rejected reasoning on those specific grounds and directs the USPTO to reconsider under corrected legal standards. This does not guarantee patent issuance — it means the USPTO must re-examine the vacated rejections. The ultimate outcome depends on subsequent USPTO proceedings.
The basis of termination notes the appeal was ‘dismissed in part,’ which typically indicates that certain issues lacked the procedural prerequisites for Federal Circuit review — such as finality of the USPTO’s decision, jurisdictional standing, or proper exhaustion of administrative remedies. The public record does not specify which claims or grounds were dismissed on procedural rather than merits grounds.
Dichlorphenamide is a carbonic anhydrase inhibitor approved by the FDA for primary periodic paralysis, a rare neuromuscular condition. Method-of-treatment patents covering its use can restrict generic competitors from offering identical treatment regimens even after compound patents expire. In rare disease markets with limited alternatives and high treatment costs, such patents carry significant commercial weight for both originators and generic entrants.
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