Astellas v. Humanwell PuraCap & Epic Pharma: Dismissed With Prejudice in 140 Days
Astellas Pharma, The Regents of the University of California, and Medivation filed a patent infringement action in New Jersey District Court against Humanwell PuraCap and Epic Pharma over two diarylhydantoin compound patents. The case was dismissed with prejudice at plaintiffs' request within 140 days. Each side bore its own costs, and the court retained jurisdiction to enforce the parties' settlement agreement.
Pharma patent suit over diarylhydantoin compounds ends in 140 days
On 21 February 2023, Astellas Pharma Inc., Astellas Pharma US Inc., Astellas US LLC, Medivation LLC, Medivation Prostate Therapeutics LLC, and The Regents of the University of California filed an infringement action in the District of New Jersey against Humanwell PuraCap Pharmaceuticals (Wuhan) Co., Ltd. and Epic Pharma, LLC. The asserted patents — US7709517B2 and US8183274B2 — cover diarylhydantoin compounds and their use in treating hyperproliferative disorders.
The case was terminated on 11 July 2023. The recorded basis of termination is Dismissed with Prejudice. The dismissal order states that all plaintiffs' claims against the defendants with respect to the patents-in-suit were dismissed with prejudice at plaintiffs' request, with each side bearing its own costs. The order further states that the court retained jurisdiction to enforce the order and the terms of the parties' settlement agreement.
Resolution within 140 days — before any significant merits briefing on record — suggests the parties reached an agreement relatively early in the litigation. The court's express retention of jurisdiction to enforce the settlement agreement is noted in the order. The specific terms of any underlying agreement are not disclosed in the available record.
See Complete Case & Patent Analysis →Filing to Dismissed with Prejudice in 140 days
140 days — from filing to dismissal with prejudice
US7709517B2 & US8183274B2 — Diarylhydantoin Compounds
Any pharmaceutical company — branded or generic — developing diarylhydantoin compounds or compounds targeting androgen receptors in the treatment of hyperproliferative disorders should treat these two patents as live enforcement risks. The dismissal with prejudice in this case did not invalidate or limit either patent. The plaintiffs retain full enforcement rights against third parties, and the joint plaintiff structure suggests a well-resourced coalition willing to act swiftly against perceived infringers.
Official order — verbatim text
The dismissal order records that all plaintiffs' claims against the defendants with respect to the patents-in-suit were dismissed with prejudice, at plaintiffs' request, with each party bearing its own costs. The court's express retention of jurisdiction to enforce both the order and the terms of the parties' settlement agreement is the only structural detail disclosed in the public record. The specific terms of any underlying arrangement between the parties are not disclosed in the available record.
Dismissed with prejudice: what the resolution means for both parties
Dismissal with prejudice at plaintiffs' request
A dismissal with prejudice is a final adjudication on the merits — the same claims cannot be refiled against these defendants on the same patents. Here, the dismissal was entered at plaintiffs' request, consistent with the parties having reached a resolution. The court expressly retained jurisdiction to enforce the order and the terms of the parties' settlement agreement.
Final, cannot be refiledPatents US7709517B2 and US8183274B2 remain in force
The dismissal with prejudice resolves the action against Humanwell PuraCap and Epic Pharma specifically. The patents themselves are not invalidated by this order. Astellas, Medivation, and the UC Regents retain the ability to enforce US7709517B2 and US8183274B2 against other parties. The specific terms of any underlying arrangement with the defendants are not disclosed in the available record.
Patents survive; enforcement rights retainedClaims dismissed with prejudice; each side bears own costs
The dismissal with prejudice means the plaintiffs' claims against Humanwell PuraCap and Epic Pharma on these patents cannot be renewed in this forum on these facts. The cost allocation — each party bearing its own costs — is recorded in the order. The specific commercial or operational terms of any arrangement between the parties are not disclosed in the available record.
No cost award against defendantsEarly resolution signals active diarylhydantoin patent enforcement
The swift resolution of this action — within 140 days and before substantial merits litigation — is consistent with enforcement activity aimed at generic entrants in the diarylhydantoin space. Other manufacturers working with compounds covered by US7709517B2 or US8183274B2 should monitor the plaintiffs' portfolio and enforcement posture closely. The retained court jurisdiction over the settlement agreement is the only structural detail publicly available.
Generic entry risk remains liveFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Astellas Pharma, Inc. | Company | /Search in Eureka ↗ |
| Co-Plaintiff | The Regents of the University of California | Company | Search in Eureka ↗ |
| Co-Plaintiff | Astellas Pharma US, Inc. | Company | Search in Eureka ↗ |
| Co-Plaintiff | Astellas US, LLC | Company | Search in Eureka ↗ |
| Co-Plaintiff | Medivation, LLC | Company | Search in Eureka ↗ |
| Co-Plaintiff | Medivation Prostate Therapeutics, LLC | Company | Search in Eureka ↗ |
| Defendant | Humanwell Puracap Pharmaceuticals (Wuhan) Co., Ltd. | Company | /Search in Eureka ↗ |
| Co-Defendant | Epic Pharma, LLC | Company | Search in Eureka ↗ |
| Plaintiff counsel | ERIN AUSTIN | Attorney | Counsel for Astellas Pharma, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Jessica K. Formichella | Attorney | Counsel for Astellas Pharma, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Liza M. Walsh | Attorney | Counsel for Astellas Pharma, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Selena Miriam Ellis | Attorney | Counsel for Astellas Pharma, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Venable, LLP | Law Firm | Representing Astellas Pharma, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Walsh Pizzi O'reilly Falanga, LLP | Law Firm | Representing Astellas Pharma, Inc.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | New Jersey District CourtSearch in Eureka ↗ |
R&D signals in the diarylhydantoin and androgen receptor antagonist space
Forward-looking patent and R&D intelligence derived from the Astellas–UC Regents–Medivation diarylhydantoin portfolio and the competitive landscape around prostate cancer therapeutics.
Astellas & UC Regents diarylhydantoin filing activity
The joint plaintiff structure spanning Astellas, Medivation, and the UC Regents suggests a multi-layered patent portfolio around diarylhydantoin chemistry. Tracking continuation and divisional filings from the US11/433829 and US12/708523 application families can reveal how the portfolio is being extended and where new claim scope is being sought in androgen receptor antagonist chemistry.
Portfolio depth signalFiling trends in next-gen androgen receptor antagonists
The diarylhydantoin scaffold underpins a class of androgen receptor antagonists that has seen sustained innovation activity. Monitoring patent filing trends in this chemical class — particularly from academic medical centres and large pharma — can identify where the next generation of prostate cancer therapies is being developed and where freedom-to-operate gaps or crowding risks are emerging.
Competitive filing trendsHumanwell PuraCap & Epic Pharma generic pipeline signals
Humanwell PuraCap's presence as a Wuhan-based co-defendant alongside US-based Epic Pharma is consistent with a generic supply chain entering the diarylhydantoin market. Tracking their patent filings, ANDA-related activity, and any formulation IP in this class can give innovators early warning of future generic challenges in the prostate cancer drug space.
Generic pipeline riskAdjacent chemistry opportunities near diarylhydantoin patents
The concentrated claim scope of US7709517B2 and US8183274B2 in diarylhydantoin compounds for hyperproliferative disorders may leave adjacent structural chemistries or combination therapy approaches less densely covered. R&D teams exploring androgen receptor degraders (ARDs) or next-generation PROTAC-based approaches in prostate cancer may find patentable white space near but outside these patent families.
Adjacent R&D opportunitySimilar diarylhydantoin patent infringement cases in New Jersey District Court
Explore related patent infringement actions involving diarylhydantoin compounds and prostate cancer therapeutics filed in the District of New Jersey or comparable pharmaceutical patent courts.
What this case signals for the diarylhydantoin and prostate cancer IP landscape
A fast dismissal with prejudice and retained court jurisdiction over settlement terms suggests active and commercially motivated patent enforcement in this drug class.
Early dismissal with retained jurisdiction flags a structured resolution
The court's express retention of jurisdiction to enforce the settlement agreement — combined with a 140-day case lifecycle — suggests the parties reached a structured resolution rather than a simple walk-away. Companies in the diarylhydantoin or XTANDI-adjacent generics space should treat this as a signal of active, commercially engaged enforcement by the plaintiff group.
Both asserted patents remain valid and enforceable against third parties
US7709517B2 and US8183274B2 were not invalidated or amended by this proceeding. Any other generic manufacturer developing diarylhydantoin compounds — or compounds treating hyperproliferative disorders in overlapping claim scope — faces the same enforcement risk from this plaintiff coalition. A freedom-to-operate analysis against both patents remains highly relevant.
Astellas v Humanwell — key questions answered
The asserted patents were US7709517B2 (application no. US11/433829) and US8183274B2 (application no. US12/708523), covering diarylhydantoin compounds and their use in treating hyperproliferative disorders. Both patents were held within the Astellas–Medivation–UC Regents plaintiff group.
The recorded basis of termination is Dismissed with Prejudice. The dismissal order states all plaintiffs' claims against the defendants were dismissed with prejudice at plaintiffs' request, with each party bearing its own costs. The court retained jurisdiction to enforce the order and the terms of the parties' settlement agreement. The specific terms of any underlying arrangement are not disclosed in the available record.
No. A dismissal with prejudice resolves the claims between these specific parties but does not invalidate or limit the patents themselves. US7709517B2 and US8183274B2 remain in force, and the plaintiff group retains the ability to enforce them against other parties.
The dismissal order expressly states that the court retained jurisdiction to enforce the order and the terms of the parties' settlement agreement. This is consistent with the existence of an underlying settlement arrangement, though the specific terms of that arrangement are not disclosed in the available public record.
Resolution within 140 days — before substantial merits litigation on the public docket — suggests the parties reached an agreement relatively early in the proceedings. Combined with the court's retained jurisdiction over the settlement terms, the timeline is consistent with a commercially motivated resolution. Whether this reflects a licensing arrangement, market access terms, or another structure is not disclosed in the available record.
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