Nasir Hussain

As a senior associate in Winston & Strawn’s Antitrust/Competition and Government Investigations, Enforcement, and Compliance practices, Nas represents clients in antitrust disputes, regulatory investigations—including False Claims Act and Controlled Substances Act matters—internal investigations, and other complex litigation. His practice spans multiple industries, with a particular focus on healthcare and life sciences, where he brings deep sector knowledge and a keen understanding of the business of healthcare.

Nas litigates antitrust and other complex matters, including class actions, in state and federal courts nationwide. He is involved at every stage of litigation, from pre-litigation counseling and motion practice to discovery, settlement negotiations, and trial preparation. He plays a key role in developing litigation strategy and managing high-value disputes. His antitrust litigation experience includes both merger and conduct litigations. Recent matters that Nas has been involved in include:

• Representing a technology company in a landmark patent infringement and antitrust litigation involving data processing technology foundational to the development of artificial intelligence.
• Representing a generic pharmaceutical manufacturer in plaintiff-side antitrust lawsuit against brand-name pharmaceutical company, alleging unlawful restraint of trade.
• Defending a health system in a “bet-the-company” antitrust class action challenging a hospital merger.

In addition to his litigation practice, Nas frequently represents clients in matters involving federal and state regulators, including the U.S. Department of Justice, Federal Trade Commission, Drug Enforcement Administration, and Illinois Department of Financial and Professional Regulation. He has advised healthcare systems and providers in False Claims Act and Controlled Substances Act investigations, achieving favorable resolutions to complex regulatory challenges. He has also led multiple securities-related investigations before the Securities and Exchange Commission, securing successful outcomes for his clients.

Nas has substantial experience guiding clients through complex merger reviews, both in the U.S. and internationally. He has managed foreign local counsel through the merger clearance process in multiple jurisdictions for a multibillion-dollar global acquisition.

Beyond litigation and investigations, Nas serves as a key counselor on antitrust risk and healthcare regulatory compliance. He regularly advises clients on Controlled Substances Act compliance, provides tailored compliance training for legal and non-legal teams, and assists with developing and refining compliance policies.

Nas is deeply committed to pro bono work. He played a pivotal role in a landmark case defending religious freedom in the U.S. Armed Forces and successfully represented a human trafficking survivor in securing a full criminal record expungement across multiple jurisdictions. In recognition of his pro bono contributions, he was honored as the Chicago Alliance Against Sexual Exploitation’s Pro Bono Superstar of the Year.