David F. Sorensen

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David Sorensen is a Managing Shareholder and Co-Chair of the Firm’s antitrust department. He graduated from Duke University (A.B. 1983) and Yale Law School (J.D. 1989), and clerked for the Hon. Norma L. Shapiro (E.D. Pa.). He concentrates his practice on antitrust and environmental class actions.

Mr. Sorensen co-tried Cook v. Rockwell Int’l Corp., No. 90-181 (D. Colo.) and received, along with the entire trial team, the “Trial Lawyer of the Year” award in 2009 from the Public Justice Foundation for their work on the case, which resulted in a jury verdict of $554 million in February 2006, after a four-month trial, on behalf of thousands of property owners near the former Rocky Flats nuclear weapons plant located outside Denver, Colorado. The jury verdict was then the largest in Colorado history, and was the first time a jury has awarded damages to property owners living near one of the nation’s nuclear weapons sites. In 2008, after extensive post-trial motions, the District Court entered a $926 million judgment for the plaintiffs. The jury verdict in the case was vacated on appeal in 2010. In 2015, on a second trip to the Tenth Circuit Court of Appeals, Plaintiffs secured a victory with the case being sent back to the district court. In 2016, the parties reached a $375 million settlement, which received final approval in 2017.

Mr. Sorensen played a major role in the Firm’s representation of the State of Connecticut in State of Connecticut v. Philip Morris, Inc., et al., in which Connecticut recovered approximately $3.6 billion (excluding interest) from certain manufacturers of tobacco products. And he served as co-lead class counsel in Johnson v. AzHHA, et al., No. 07-1292 (D. Ariz.), representing a class of temporary nursing personnel who had been underpaid because of an alleged conspiracy among Arizona hospitals. The case settled for $24 million.

Mr. Sorensen also has played a leading role in numerous antitrust cases representing direct purchasers of prescription drugs. Many of these cases have alleged that pharmaceutical manufacturers have wrongfully kept less expensive generic drugs off the market, in violation of the antitrust laws. Many of these cases have resulted in substantial cash settlements, including King Drug Co. v. Cephalon, Inc., (E.D. Pa.) ($512 million partial settlement – largest ever for a case alleging delayed generic competition); In re: Aggrenox Antitrust Litigation ($146 million settlement); In re: K-Dur Antitrust Litigation ($60.2 million); In re: Prandin Direct Purchaser Antitrust Litigation ($19 million); In re: Doryx Antitrust Litigation ($15 million); In re: Skelaxin Antitrust Litigation ($73 million); In re: Wellbutrin XL Antitrust Litigation ($37.50 million); In re: Oxycontin Antitrust Litigation ($16 million); In re: DDAVP Direct Purchaser Antitrust Litigation ($20.25 million settlement following precedent-setting victory in the Second Circuit, which Mr. Sorensen argued, see 585 F.3d 677 (2d Cir. 2009)); In re: Nifedipine Antitrust Litigation ($35 million); In re: Terazosin Hydrochloride Antitrust Litigation, MDL 1317 (S.D. Fla.) ($74.5 million); and In re: Remeron Antitrust Litigation ($75 million). Mr. Sorensen is serving as co-lead counsel or on the executive committee of numerous similar, pending cases.

In 2017, the American Antitrust Institute presented its Antitrust Enforcement Award to Mr. Sorensen and others for their work on the K-Dur case. In 2019, Mr. Sorensen and his team won AAI’s Outstanding Antitrust Litigation Achievement in Private Practice Award for their work on King Drug Co. of Florence, Inc. v. Cephalon, Inc. (Provigil).

Professional Leadership

  • Has presented at a number of symposia relating to antitrust issues in the pharmaceutical industry, including conferences in 2015 and 2014 in Philadelphia sponsored by HarrisMartin concerning “Pay for Delay” agreements.

Prominent Judgments and Settlements

In the News



Law School

Yale Law School, J.D.


Duke University, B.A., magna cum laude

Honors & Awards:

  • Named a 2019 Lawdragon 500 Leading Plaintiff Financial Lawyer

  • Winner of AAI’s 2019 Outstanding Antitrust Litigation Achievement in Private Practice Award for his work in King Drug Co. of Florence, Inc. v. Cephalon, Inc. (Provigil)

  • Winner of AAI’s 2017 Antitrust Enforcement Award for his work in In re: K-Dur Antitrust Litigation

  • Among the trial team named as 2009 “Trial Lawyer of the Year” by the Public Justice Foundation for his work in Cook v. Rockwell Int’l Corporation

  • “AV” Peer Review Rated, Martindale Hubbell, representing the highest rating for professional excellence

  • Designated a “Pennsylvania Super Lawyer” by Philadelphia and Law and Politics magazines, a distinction awarded to only 5% of the attorneys in the state


  • Chimerical Class Conflicts in Federal Antitrust Litigation: The Fox Guarding the Chicken House in Valley Drug, 39 U.S.F. L. Rev. 141 (Fall 2004), co-authored by Mr. Sorensen and Joshua P. Davis, law professor at the San Francisco School of Law

  • Model Jury Instructions: Trial by Actavis, 67 RUTGERS L. REV. 637 (Spring 2015), co-authored with Steve D. Shadowen


Member – Pennsylvania Bar

Admitted – Eastern District of Pennsylvania

Admitted – U.S. Supreme Court

Admitted – Several Federal Courts of Appeal


Law Clerk to the Honorable Norma L. Shapiro (E.D. Pa.)

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