Bionpharma v. Silvergate Pharmaceuticals: Federal Circuit Appeal Voluntarily Dismissed
Bionpharma, Inc. and Silvergate Pharmaceuticals, Inc. clashed at the Federal Circuit over four patents covering enalapril maleate oral solution at 1 mg/mL — the formulation marketed as Epaned®. The parties jointly agreed to dismiss the appeal under Fed. R. App. P. 42(b), closing the proceeding after just 48 days with no merits ruling issued.
A 48-day Federal Circuit exit: four enalapril patents, no merits ruling
Filed on 5 November 2024, Case No. 25-1148 brought Bionpharma, Inc. before the United States Court of Appeals for the Federal Circuit against Silvergate Pharmaceuticals, Inc. The dispute centred on an infringement action involving four US patents — US9808442B2, US10039745B2, US10154987B2, and US9669008B1 — all relating to enalapril maleate oral solution formulations at a proposed strength of 1 mg/mL, the active ingredient in Azurity’s and Bionpharma’s competing Epaned® products.
The proceeding closed on 23 December 2024 when both parties jointly agreed to dismiss the appeal under Federal Rule of Appellate Procedure 42(b). The court ordered the dismissal accordingly. No merits determination was issued — the Federal Circuit did not rule on infringement, validity, or any substantive patent question. The public record does not specify whether the dismissal was with or without prejudice, leaving the exact preclusive effect of the termination ambiguous.
The 48-day duration from filing to closure is notably brief for a Federal Circuit appeal, which typically takes well over a year to resolve on the merits. This compressed timeline suggests the parties likely reached a private resolution — possibly a licensing arrangement, settlement, or commercial agreement — before any substantive briefing was completed. What drove the agreement and whether any financial terms were exchanged remain unknown from the publicly available record.
Filing to Voluntary dismissal in 48 days
48 days — well below the typical Federal Circuit appeal cycle of 12–24 months, suggesting early resolution
Voluntarily dismissed: what the agreed exit means for both parties
Fed. R. App. P. 42(b): a consent-based appellate exit
Rule 42(b) of the Federal Rules of Appellate Procedure permits an appeal to be dismissed upon the agreement of all parties. Here, both Bionpharma and Silvergate consented, and the Federal Circuit ordered dismissal accordingly. Crucially, no merits ruling was issued — the court made no determination on infringement, patent validity, or claim scope. The underlying substantive dispute was never adjudicated at the appellate level.
No merits adjudicationWith or without prejudice? The public record is silent
A voluntary dismissal ‘with prejudice’ bars the dismissing party from re-filing the same claims — it functions as a final judgment on the merits. A dismissal ‘without prejudice’ preserves the right to refile. The public docket for Case 25-1148 does not specify which applies here. Practitioners should treat the preclusive effect as uncertain unless the underlying settlement agreement or any sealed court order clarifies the terms.
Preclusive effect uncertainBionpharma exits the appeal with no Federal Circuit ruling
As the appellant, Bionpharma agreed to dismiss its own appeal, suggesting it no longer sought the Federal Circuit’s review of the lower decision — at least under these circumstances. This could reflect a commercial resolution, a shift in litigation strategy, or a licensing agreement. Without a merits ruling, Bionpharma receives no appellate vindication, but also avoids an adverse Federal Circuit precedent against it on these four patents.
No adverse precedent createdSilvergate avoids appellate scrutiny of the lower court ruling
Silvergate Pharmaceuticals, as the appellee, agreed to the dismissal, which means the lower court decision — whatever it held — is not formally affirmed or disturbed by the Federal Circuit. Silvergate avoids the risk of a reversal or unfavourable appellate precedent, but equally gains no strengthened Federal Circuit endorsement of its patent position. The commercial value of any IP rights involved remains contingent on any private resolution terms.
Lower ruling neither affirmed nor reversedFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Bionpharma, Inc. | Company | Generic pharmaceutical company — appellant asserting rights related to four enalapril maleate solution patentsSearch in Eureka ↗ |
| Defendant | Silvergate Pharmaceuticals, Inc. | Company | Specialty pharmaceutical company — appellee defending against enalapril maleate oral solution infringement claimsSearch in Eureka ↗ |
| Plaintiff counsel | Brian Murray | Attorney | Counsel for Bionpharma, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Charles A. Weiss | Attorney | Counsel for Bionpharma, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Holland & Knight, LLP | Law Firm | Representing Bionpharma, Inc.Search in Eureka ↗ |
| Defendant counsel | Jack B. Blumenfeld | Attorney | Counsel for Silvergate Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant law firm | Morris, Nichols, Arsht & Tunnell LLP | Law Firm | Representing Silvergate Pharmaceuticals, Inc.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | Court of Appeals for the Federal CircuitSearch in Eureka ↗ |
Official order — verbatim text
The order records a consent dismissal under Fed. R. App. P. 42(b), noting only that ‘the parties having so agreed.’ This phrasing confirms mutual consent but provides no indication of underlying terms, financial consideration, or licensing arrangements. Critically, the order does not specify whether the dismissal is with or without prejudice — a material omission that leaves the preclusive scope of this termination unresolved on the public record. No substantive ruling on the four enalapril maleate patents was issued.
US9808442B2 — enalapril maleate oral solution formulations
The four patents at issue — US9808442B2, US10039745B2, US10154987B2, and US9669008B1 — form a related family directed to enalapril maleate oral solution, an ACE inhibitor formulation used in the treatment of hypertension, including in paediatric patients. The application numbers (US15/613622, US15/802341, US16/003994, US15/081603) reflect a prosecution timeline consistent with iterative claim refinement around composition, formulation stability, and method-of-use parameters for a 1 mg/mL oral liquid dosage form.
Enalapril maleate oral solutions occupy a commercially sensitive niche: the paediatric cardiovascular market where liquid dosage forms are medically necessary and brand-generic competition is intense. A patent family covering multiple aspects of the same 1 mg/mL formulation — as these four patents appear to do — creates a defensive perimeter that is difficult for generic entrants to design around without risking multi-front infringement exposure. The Epaned® brand’s market position makes this family strategically significant beyond this single appeal.
Should your team run an FTO against US9808442B2 and the Epaned® patent family?
Any company developing, manufacturing, or commercialising an enalapril maleate oral solution — particularly at or near 1 mg/mL concentration — should treat this four-patent family as a priority FTO target. The voluntary dismissal of this appeal does not extinguish the patents or limit their enforceability. Generic manufacturers, compounding pharmacies, and specialty pharma companies entering the paediatric cardiovascular oral liquid space face real infringement risk if these claims are not cleared.
PatSnap Eureka’s FTO Search Agent can map the full claim scope of US9808442B2, US10039745B2, US10154987B2, and US9669008B1 against your formulation parameters, flag prior art that may support validity challenges, and surface related prosecution history that could inform design-around strategies. For teams building paediatric oral liquid pipelines, running a structured FTO now — before ANDA filing or commercial launch — is materially lower-risk than litigating it later at the Federal Circuit.
Run a freedom-to-operate analysis on US9808442B2 to assess your product’s exposure
Run FTO in Eureka →Similar Federal Circuit appeals in pharmaceutical oral solution patent litigation
Cases involving enalapril maleate oral solution patents and ACE inhibitor formulation disputes at the Federal Circuit, with comparable voluntary dismissal or ANDA-related infringement profiles.
What this case signals for the pharmaceutical formulation IP landscape
A 48-day Federal Circuit exit over four enalapril formulation patents suggests commercial leverage, not courtroom conviction, drove the outcome.
Early Federal Circuit dismissals often mask significant licensing activity
When both parties to a Federal Circuit appeal jointly agree to dismiss within 48 days of filing — before any briefing schedule is complete — the most probable driver is a private commercial resolution. Companies competing in the same branded generic space, as Bionpharma and Silvergate do with Epaned®, have strong commercial incentives to settle rather than generate adverse precedent on formulation patents.
Four asserted patents signals broad formulation claim coverage worth monitoring
Asserting four patents across the same enalapril maleate oral solution indicates layered claim protection — likely spanning composition, formulation method, stability, and dosing parameters. Competitors developing paediatric oral liquid formulations in this therapeutic area should treat this patent family as a live enforcement risk, regardless of this appeal’s dismissal without merits adjudication.
Bionpharma v Silvergate — key questions answered
The Federal Circuit appeal (Case 25-1148) was voluntarily dismissed under Fed. R. App. P. 42(b) by agreement of both parties on 23 December 2024, just 48 days after filing. No merits ruling was issued on the four enalapril maleate oral solution patents (US9808442B2, US10039745B2, US10154987B2, US9669008B1). The public record does not specify whether the dismissal was with or without prejudice.
Four US patents were asserted, all relating to enalapril maleate oral solution formulations at 1 mg/mL: US9808442B2 (application US15/613622), US10039745B2 (application US15/802341), US10154987B2 (application US16/003994), and US9669008B1 (application US15/081603). These patents cover the formulation marketed as Epaned® by Azurity/Silvergate.
A Rule 42(b) dismissal is a procedural termination agreed by the parties — it does not affect the validity or enforceability of the underlying patents. The four enalapril maleate patents remain in force unless separately challenged or invalidated. The dismissal means the Federal Circuit issued no ruling on infringement or claim scope, so no appellate precedent was created either for or against the patent holder.
The public docket and court order do not specify whether the voluntary dismissal was with or without prejudice. The order states only that ‘the parties having so agreed’ and orders dismissal under Rule 42(b). This ambiguity is legally significant: a with-prejudice dismissal bars re-litigation; a without-prejudice dismissal preserves refiling rights. Practitioners should treat the preclusive effect as uncertain absent access to sealed settlement terms.
The 48-day resolution is unusually rapid for a Federal Circuit appeal, which typically unfolds over 12–24 months. The speed of the agreed dismissal — before substantive briefing — suggests the parties likely reached a private commercial resolution, potentially including licensing or market access terms relating to the Epaned® enalapril maleate oral solution. The specific terms driving the agreement are not disclosed in the public record.
PatSnap Eureka searches patents and litigation data to answer instantly.