Dennie B. Zastrow

Associate
He/Him/His

Dennie B. Zastrow’s antitrust practice ranges from regulatory counseling on mergers and acquisitions to private antitrust litigation in US federal and state courts. Prior to joining Morgan Lewis, Dennie was an associate in the Philadelphia office of a national law firm and focused his practice on antitrust litigation, counseling, and merger review. Dennie has experience with matters in a variety of industries, including healthcare, life sciences, pharmaceuticals, and retail. He is a member of the firm’s antitrust working group on artificial intelligence and algorithmic pricing issues.

During law school, Dennie interned with Judge C. Darnell Jones II of the US District Court for the Eastern District of Pennsylvania through the Federal Judicial Clerkship Clinical Honors Program of Temple University’s Beasley School of Law. He also served as a staff editor of the Temple Law Review.

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  • Defending a large healthcare provider against a putative class action alleging that the provider and its clinically integrated network of outpatient providers engaged in exclusive dealing, tying, and price fixing in violation of Sherman Act Sections 1 and 2
  • Representing a defendant in numerous antitrust class actions throughout the country in which plaintiffs are challenging the financial structure of the US residential real estate industry
  • Defending a retail company against an action alleging a conspiracy related to the enforcement of a noncompete
  • Defended a branded pharmaceutical manufacturer against class action claims arising out of an alleged horizontal conspiracy to delay and order market entry with respect to gout drug Colcrys
  • Defended a generic pharmaceutical manufacturer in multidistrict price-fixing litigation
  • Represented Intercontinental Exchange Inc. in its $16 billion proposed acquisition of Black Knight Inc. (Federal Trade Commission)
  • Represented Amerisource Bergen in the sale of its specialty pharmacy, US Bioservices, to CVS Health (Federal Trade Commission)
  • Represented Perrigo Co. plc in its $2.1 billion acquisition of Hera SAS (HRA Pharma) (Federal Trade Commission)
  • Represented a nonparty in connection with a subpoena for testimony in FTC v. GTCR BC Holdings, LLC (N.D. Ill.)
  • Temple University Beasley School of Law, 2017, J.D., magna cum laude
  • University of Pennsylvania, Fels Institute of Government, 2012, M.P.A.
  • University of Pennsylvania, 2010, B.A.
  • Pennsylvania
  • US Court of Appeals for the Eighth Circuit
  • US District Court for the Eastern District of Pennsylvania

40 under 40, City and State Pennsylvania (2023)

Recognized, Best LGBTQ+ Lawyers Under 40, National LGBT Bar Association (2025)

Volunteer Attorney of the Year, Philadelphia Volunteer Lawyers for the Arts (2023)

Member, Practice Group of the Year, Competition, Law360 (2021)

Member, Antitrust Section, American Bar Association

Member, Antitrust Section Pricing Conduct Advisory Board, American Bar Association

Young Lawyer Representative, Antitrust Section Unilateral Conduct Committee, American Bar Association (2022–2023)

Member, National LGBT Bar Association

Member, Philadelphia Bar Association

Member, Board of Governors, Human Rights Campaign (2020–2024)

Young Lawyer Representative, Long Range and Strategic Planning Committee, American Bar Association (2023–2025)