To stay ahead of litigation trends in evolving industries, WIT regularly examines its core practice areas to identify patterns in past disputes and anticipate where future challenges may arise. In this follow-up to our previous analysis of BPCIA biologics litigation, we shift our focus from the products and patents at issue to the players driving the disputes: the courts hearing these cases, the judges overseeing them, the parties involved, and the law firms and attorneys leading the charge. By analyzing a decade’s worth of filings, we’re gaining insight into how venue strategy, repeat players, and specialized counsel are shaping the contours of this complex and competitive legal landscape.

Let’s take a closer look.

Q: Which federal district courts are most frequently involved in BPCIA biologics litigation?

A: BPCIA litigation is highly concentrated in a few venues. The District of Delaware tops the list, handling over a third (37%) of all cases. The District of New Jersey follows at 24%, with all other courts falling well below 15%.

This venue concentration isn’t surprising. Both Delaware and New Jersey are home to many U.S. pharmaceutical company headquarters or subsidiaries, giving rise to personal jurisdiction. These courts also have deep experience with complex patent cases and well-established local rules for managing Hatch-Waxman and BPCIA litigation. In particular, the judges in these districts are known for handling high-stakes pharmaceutical patent disputes efficiently, making them favored forums for both plaintiffs and defendants.

The Northern District of West Virginia — where Mylan was historically headquartered — also appears more frequently due to venue ties in specific biosimilar cases.

District CourtTotal casesTotal cases %
District of Delaware2037.04%
District of New Jersey1324.07%
Northern District of West Virginia611.11%
Southern District of Florida35.56%
District of Massachusetts23.70%
Northern District of California23.70%
Northern District of Illinois23.70%
Central District of California11.85%
Southern District of California11.85%
Eastern District of North Carolina11.85%
Western District of Pennsylvania11.85%
Eastern District of Texas11.85%
Eastern District of Virginia11.85%
Grand Total54100.00%

Q: Are certain judges consistently overseeing BPCIA cases, and what does that suggest about venue strategy?

A: A handful of judges have become recurring figures in BPCIA litigation, reinforcing the strategic pull of certain districts. Chief Judge Colm Connolly of the District of Delaware has presided over nearly a quarter of all cases (24%), far more than any other judge. In New Jersey, Judges Christine O’Hearn and Renée Bumb each account for about 7% of cases, followed by Judge Claire Cecchi at 6%. And in the Northern District of West Virginia, Judge Thomas Kleeh oversaw all six cases filed there.

This concentration suggests that parties are not only choosing districts with established pharmaceutical expertise, but are also becoming familiar with — and potentially planning around — the practices and preferences of specific judges. Knowing how a judge approaches scheduling, discovery disputes, and claim construction can be a meaningful advantage in high-stakes BPCIA litigation.

JudgeTotal casesTotal cases %
District of Delaware
Colm Felix Connolly1324.07%
Gregory Brian Williams23.70%
Leonard Philip Stark11.85%
Maryellen Noreika11.85%
Mitchell S. Goldberg11.85%
Richard Gibson Andrews11.85%
Sue Lewis Robinson11.85%
District of New Jersey
Christine Patricia O’Hearn47.41%
Claire Claudia Cecchi35.56%
Freda L. Wolfson11.85%
Madeline Cox Arleo11.85%
Renée Marie Bumb47.41%
Northern District of West Virginia
Thomas Shawn Kleeh611.11%
Southern District of Florida
James I. Cohn23.70%
William P. Dimitrouleas11.85%
District of Massachusetts
Leo Theodore Sorokin11.85%
Mark Lawrence Wolf11.85%
Northern District of California
Richard G. Seeborg23.70%
Northern District of Illinois
John Robert Blakey11.85%
John Zihun Lee11.85%
Central District of California
John William Holcomb11.85%
Southern District of California
Ruth Bermudez Montenegro11.85%
Eastern District of North Carolina
Richard Ernest Myers II11.85%
Western District of Pennsylvania
Mark Raymond Hornak11.85%
Eastern District of Texas
James Rodney Gilstrap11.85%
Eastern District of Virginia
Robert George Doumar11.85%
Grand Total54100.00%

Q: Which parent companies are most active in BPCIA litigation and who represents them?

A: Unsurprisingly, Amgen dominates BPCIA litigation, appearing in over 20 cases, which is more than any other company by a wide margin. It frequently appears as both plaintiff and defendant, reflecting its early entry into the biosimilars market and robust patent portfolio. Amgen’s litigation is spread across several major firms, including Paul Weiss, Sidley Austin, Proskauer Rose, and Dechert, showing a strategic approach that leverages multiple specialized teams depending on the case.

Other highly active companies include:

  • Regeneron: involved in at least 7 cases, frequently represented by Kellogg Hansen, Williams & Connolly, and Weil Gotshal.
  • Celltrion, Sandoz, and Samsung also appear repeatedly, often teaming with firms like Fish & Richardson, Goodwin, and Quinn Emanuel.

The data suggests that larger players are deploying a deep bench of outside counsel, often partnering with firms experienced in both life sciences IP and high-stakes litigation. The variation in firm selection — even within the same company — reflects the complexity and nuance of BPCIA disputes, where venue, judge familiarity, and specific scientific issues all factor into representation strategy.

Total Cases by Law Firm or Counsel and Parent Company
Total cases
Law FirmParentTotal
A&O ShearmanFresenius Kabi2
Novartis1
Lek1
Akin Gump Strauss Hauer & FeldJanssen1
Amgen1
Alston & BirdAmgen1
Amgen (In-House Counsel)Amgen20
Ashby & GeddesSamsung1
BakerHostetlerHospira1
Bayhealth Medical CenterBoehringer Ingelheim1
Bienert Katzman Littrell WilliamsRegeneron1
Bowles Rice McDavid Graff & LoveCelltrion1
Amgen1
BracewellAmgen1
Burns & LevinsonHospira1
Celltrion1
Buscher PatentAlvotech1
Cahill Gordon & ReindelAlexion1
Carey, Scott, Douglas & KesslerRegeneron6
Carlton FieldsJanssen1
Choate Hall & StewartBiogen2
Kashiv1
Bio-Thera1
Amneal1
Adello1
Coats & BennettIntas1
Accord1
Connell FoleyAmgen1
Roche1
Immunex1
Connolly GallagherPfizer2
Hospira2
CooleyAmgen2
Samsung1
Teva1
Celltrion1
Covington & BurlingCity of Hope1
Roche1
Genentech1
Cozen O’ConnorApotex2
Accord1
Cravath, Swaine & MooreAmgen1
Crowell & MoringTanvex1
DechertAmgen6
Delaware Court of ChanceryBoehringer Ingelheim1
Delaware Department of JusticeAmgen4
FarnanGSK1
Finnegan, Henderson, Farabow, Garrett & DunnerAbbVie4
Fish & RichardsonSamsung5
Alvotech2
Amgen1
Janssen1
Formycon1
Celltrion1
Flaherty Sensabaugh BonassoSandoz1
Gemini LawCelltrion2
GibbonsAmgen2
Roche2
Immunex1
Gillam & SmithGenentech1
GoodwinCelltrion3
Teva3
Sandoz2
Greenberg TraurigTeva1
AbbVie1
Haug PartnersBiogen1
Hendrickson & LongAmgen1
Heyman Enerio Gattuso & HirzelPfizer3
Hospira2
Hill WallackSandoz4
Dr. Reddy’s1
Novartis1
Fresenius Kabi1
Lek1
Hissam Forman Donovan RitchieCelltrion1
Hogan LovellsAmgen3
Horn, Aylward & BandyRegeneron3
Irell & ManellaBiogen3
Genentech3
City of Hope3
Roche2
Jenner & BlockSamsung2
Alvotech1
Formycon1
Celltrion1
Coherus1
Kellogg, Hansen, Todd, Figel & FrederickRegeneron7
Kirkland & EllisSandoz3
Amgen2
Samsung2
Polpharma1
Celltrion1
Hospira1
Lek1
Kramer Levin Naftalis & FrankelAmgen1
Latham & WatkinsAbbVie5
Amgen2
Janssen1
Leydig, Voit & MayerSamsung2
Fresenius Kabi2
Biocon1
Mylan1
Amgen1
Janssen1
London & MeadAmgen1
MacCord MasonAmgen1
Manchin FerrettiCelltrion1
Mark Stein LawAccord1
Marshall, Gerstein & BorunAmgen5
Celltrion1
McAndrews, Held & MalloyAccord2
Intas1
McCarter & EnglishGenentech7
City of Hope5
AbbVie3
Roche2
Janssen1
Biogen1
Alexion1
MerusSandoz1
Midlige RichterCelltrion2
Sandoz1
Mintz, Levin, Cohn, Ferris, Glovsky and PopeoAmgen5
Morgan, Lewis & BockiusAdello1
Bio-Thera1
Amneal1
Morris JamesCoherus1
Morris, Nichols, Arsht & TunnellGenentech3
City of Hope3
Amgen2
Roche2
Biogen1
Morrison & FoersterGenentech10
City of Hope9
Sandoz4
Roche3
Lek2
Polpharma1
Novartis1
Munger, Tolles & OlsonAmgen2
AbbVie1
Nutter, McClennen & FishRoche1
Janssen1
Chugai1
Genentech1
Orrick, Herrington & SutcliffeAmgen3
Genentech2
Immunex1
Biogen1
Roche1
City of Hope1
Patterson Belknap Webb & TylerJanssen2
Patunas LawSamsung1
Paul HastingsBoehringer Ingelheim1
Paul, Weiss, Rifkind, Wharton & GarrisonAmgen11
Regeneron5
Phillips ADRLayn R. Phillips1
Pietragallo Gordon Alfano Bosick & RaspantiMylan1
Pillsbury Winthrop Shaw PittmanAmgen1
Potter Anderson & CorroonSamsung1
Proctor HeymanHospira1
Proskauer RoseAmgen6
Immunex1
Quinn Emanuel Urquhart & SullivanAmgen2
Samsung2
Celltrion1
Rakoczy Molino Mazzochi SiwikMylan2
Amgen1
Fresenius Kabi1
Biocon1
Dr. Reddy’s1
Regeneron PharmaceuticalsRegeneron1
Richards, Layton & FingerAmgen5
Genentech5
City of Hope5
Rivkin RadlerAdello1
Kashiv1
Amneal1
Robinson MillerCity of Hope3
Genentech3
Biogen3
Roche2
Regeneron1
Samsung1
Novartis1
Lek1
Ross Aronstam & MoritzAbbVie2
Rothwell, Figg, Ernst & ManbeckAmgen2
Celltrion1
Russ August & KabatAmgen2
Immunex1
SaiberFresenius Kabi1
Saul Ewing Arnstein & LehrSamsung2
Boehringer Ingelheim1
Schertler & OnoratoAmgen1
Schnader Harrison Segal & LewisSandoz1
Schrader Companion Duff & LawSamsung2
Celltrion1
Shaw KellerCelltrion2
Teva2
Samsung1
Shook, Hardy & BaconAbbVie1
Sidley AustinAmgen10
Roche2
Immunex2
Simmerman Law OfficeSamsung2
Celltrion1
Smith, Katzenstein & JenkinsAmgen2
Steptoe & JohnsonAmgen1
Mylan1
Biocon1
Sterne, Kessler, Goldstein & FoxSandoz1
Celltrion1
The Webb Law Firm (webblaw.com)Amgen1
Thomas Combs & SpannFormycon1
Celltrion1
Troutman Pepper LockeAbbVie2
Umhofer, Mitchell & KingRegeneron1
Vandeventer BlackAbbVie1
Walsh Pizzi O’Reilly FalangaAmgen7
Roche2
Immunex2
Teva1
Celltrion1
Weil, Gotshal & MangesRegeneron7
White & CaseHospira3
Pfizer3
Samsung1
Wilentz, Goldman & SpitzerSandoz2
Lek1
Novartis1
Williams & ConnollyRegeneron7
Genentech6
City of Hope4
Roche3
Amgen2
Chugai1
Willkie Farr & GallagherCelltrion2
Pfizer2
Hospira1
WilmerHaleGenentech7
City of Hope6
AbbVie3
Roche2
Wilson Robertson & CorneliusCentus1
Winston & StrawnSandoz2
Hospira2
Roche1
Pfizer1
Celltrion1
Amgen1
Immunex1
Young Conaway Stargatt & TaylorAmgen5
Samsung1
Sandoz1
Immunex1
Polpharma1
Grand Total54

Q: Which attorneys and law firms appear most frequently in BPCIA biologics litigation, and what can that tell us about who’s leading the charge in this niche field?

A: The attorneys most active in BPCIA litigation cluster around a handful of powerhouse firms—many with deep IP benches and long track records in life sciences disputes. Unsurprisingly, in-house counsel at Amgen dominate the top of the list, with Wendy Whiteford leading all attorneys by appearing in 14 cases, followed closely by Kimberlin Morley, Lois Kwasigroch, and others from Amgen’s experienced internal legal team. This underscores Amgen’s central role in shaping BPCIA litigation strategy from the inside out.

Among outside counsel, three firms stand out:

  • Williams & Connolly: Led by litigators like Thomas Fletcher and David Berl (each with 14 cases), this team is frequently tapped for its trial expertise and biotech depth.
  • Paul, Weiss: Attorneys such as Jennifer Wu, Nicholas Groombridge, and Stephen Maniscalco appear across multiple high-profile matters, reflecting the firm’s expanding biotech IP footprint.
  • WilmerHale and Sidley Austin also field robust BPCIA teams, with multiple attorneys appearing in 5+ cases each—particularly William Lee (WilmerHale) and Sue Wang (Sidley).

These repeated appearances signal more than just client trust — they suggest deep familiarity with the procedural and scientific complexity of BPCIA cases. Many of these litigators are becoming go-to names in biosimilar litigation, shaping case law and influencing how future disputes will be tried.

Most Appearing Law Firms / Counsel by Most Appearing Lawyers
Total cases
FirmLawyerTotal
AmgenWendy Ann Whiteford14
Kimberlin L. Morley7
Lois Marie Kwasigroch6
Eric Michael Agovino6
James Asa High Jr.6
Alaina Marie Whitt5
Paula Suzanne Fritsch5
J. Drew Diamond5
Christina Nichole Gifford4
Nancy Jean Gettel3
Paul, Weiss, Rifkind, Wharton & GarrisonJennifer H. Wu11
Stephen Accursio Maniscalco9
Nicholas Philip Groombridge8
Jacob Tinsley Whitt8
Peter Christian Sandel6
Eric Alan Stone5
Priyata Y. Patel5
Christopher M. Pepe5
Naz Erdeniz Wehrli5
Elizabeth Stotland Weiswasser4
Williams & ConnollyThomas Steven Fletcher14
David I. Berl14
Teagan James Gregory11
Kathryn Schleckser Kayali10
Haylee Bernal Anderson7
Jennalee N. Beazley7
Arthur John Argall III7
Andrew Vincent Trask7
Adam Pan7
Ellen Elizabeth Oberwetter7
Morrison & FoersterAdam Robert Brausa9
Daralyn Jeannine Durie9
Eric Christopher Wiener6
Erik Jeffrey Olson4
Eric Chingyun Pai3
Brian Matthew Kramer3
Evelyn Li-Jin Chang2
James R. Hancock2
Aaron Gabriel Fountain2
Eneda Hoxha2
McCarter & EnglishDaniel M. Silver10
Michael P. Kelly (McCARTER & ENGLISH)8
Alexandra M. Joyce8
Benjamin A. Smyth2
Cynthia Stencel Betz1
Mark M. Makhail1
Ravin R. Patel1
Maliheh Zare1
John E. Flaherty1
WilmerHaleWilliam Frank Lee8
Robert J. Gunther Jr.7
Kevin Scott Prussia6
Andrew J. Danford6
Stephanie T. Neely5
Emily R. Whelan5
Timothy Andrew Cook5
Nora Quinto Passamaneck5
Lisa J. Pirozzolo5
Nancy Lynn Schroeder4
Sidley AustinSue Wang9
Samuel N. Tiu8
Jeffrey Paul Kushan8
Steven Joseph Horowitz8
Nathaniel Carrick Love6
Joshua John Fougere6
Daviid Lloyd Anderson6
Lauren Cranford Katzeff6
Vernon Michael Winters4
James Asa High Jr.3
Richards, Layton & FingerRobert W. Whetzel5
Alexandra M. Ewing5
Jason James Rawnsley4
Katharine Lester Mowery4
Tyler E. Cragg3
Frederick L. Cottrell III2
Nicole Kathleen Pedi1
Fish & RichardsonMadelyn Sara McCormick5
Robert M. Oakes5
Qiuyi Wu4
Andria Rae Crisler4
Taylor Caldwell Burgener4
Jonathan Elliot Singer4
John Cameron Adkisson3
Ahmed Jamal Davis2
Jenny A. Shmuel2
Douglas Edward McCann2
Latham & WatkinsMichael Andre Morin6
David Penn Frazier6
Herman Heng Yue4
Gabrielle Ashleigh LaHatte4
Michael R. Seringhaus3
Inge A. Osman3
Roger J. L. Chin2
Tara D. Elliott2
Jacob Tinsley Whitt2
Arlene Lee Chow1
Grand Total50

Q: Which companies appear most often as plaintiffs and which as defendants in BPCIA biologics litigation, and what does that reveal about their roles in shaping the market?

A: The data shows a clear split between originator companies, who dominate as plaintiffs, and biosimilar manufacturers, who most often appear as defendants. Leading the charge is Amgen, which stands out as the most active plaintiff by far, with 20 appearances in that role (and 8 as a defendant), underscoring its dual position as both an aggressive enforcer of biologic IP and a key player in biosimilar development.

Other frequent plaintiffs include:

  • Genentech (17 plaintiff appearances)
  • Regeneron Pharmaceuticals (7)
  • AbbVie (4)
  • Janssen Biotech (3)

Meanwhile, biosimilar makers like Samsung Bioepis, Celltrion, and Sandoz appear more frequently on the defense side. For instance, Samsung Bioepis and Celltrion Healthcare have 4+ defendant-side appearances each, reflecting their active efforts to bring biosimilars to market, often into patent-heavy therapeutic areas.

This divide reflects broader market dynamics: originators are focused on defending exclusivity, while biosimilar developers are testing the boundaries of early entry. The heavy litigation activity on both sides speaks to the competitive pressure in high-value drug classes, especially as more biologics reach the end of exclusivity and the FDA’s biosimilar pathway matures.

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