Aaron J. Marks is a member of Cohen Milstein’s Antitrust practice. He represents a broad range of individuals, businesses, and public entities in civil litigation, with a focus on multi-district class actions and antitrust litigation.
Prior to joining the firm, Aaron was a law clerk for the Honorable Carol Bagley Amon of the United States District Court for the Eastern District of New York. Before his clerkship, he was a litigation associate with a distinguished international law firm.
During law school, Aaron was online editor of the Harvard National Security Journal.
Aaron serves as editor of the D.C. chapter in “The Law of Class Action: Fifty-State Survey,” the treatise published annually by the American Bar Association. He also serves on the Antitrust & Trade Regulation Committee of the New York City Bar Association and is a member of the American Bar Association’s Antitrust Section. In addition, Aaron has testified before the Advisory Committee on the Federal Rules of Civil Procedure.
Prior to pursuing a career in law, Aaron was a software engineer.
- New York City Bar Association, Antitrust and Trade Regulation Committee
- American Bar Association, Antitrust Section
- Aaron represents disability-rights organizations in connection with a certified class-action against Lyft, Inc. brought under the Americans with Disabilities Act.
- New York
- Pennsylvania
- Harvard Law School, J.D., magna cum laude, 2018
- New York University, B.A., 2013
- Law Clerk, the Hon. Carol Bagley Amon, U.S. District Court for the Eastern District of New York (2020 – 2021)
Current Cases
Tracleer Antitrust Litigation
Government Employees Health Association v. Actelion Pharmaceuticals LTD (D. Md.): Cohen Milstein is court-appointed Co-Lead Class Counsel, representing the End-Payor Class in this certified class action against Actelion Pharmaceuticals LTD, manufacturer of Tracleer, a life-saving pulmonary arterial hypertension medication. Plaintiffs allege that Actelion engaged in an anticompetitive scheme to withhold samples of from would-be rivals, under the guise of the REMS program, which ultimately delayed generic competition. On March 13, 2026, the court granted preliminary approval of a $65 million settlement. Parties reached the settlement two weeks before a 25-day jury trial was scheduled to commence.
RealPage Antitrust Litigation
District of Columbia v. RealPage, Inc. et al. (D.C. Sup. Crt.): Cohen Milstein supports the District of Columbia Attorney General’s office in a parens patriae antitrust lawsuit against RealPage, Inc. and fourteen of the largest landlords in the District for allegedly colluding to artificially inflate rents throughout the District in violation of the D.C. Antitrust Act.
In re Actos Antitrust Litigation
In re Actos Antitrust Litigation (S.D.N.Y.): Cohen Milstein represents End-Payor Plaintiffs in this antitrust action, alleging that Defendant Takeda engaged in anticompetitive conduct related to the listing of certain patents in the FDA’s Orange Book thereby resulting in unlawful delays to the market entry of generic versions of Takeda’s diabetes drug, Actos.
PBM Investigations & Litigation
PBM State Investigations: Cohen Milstein serves as Special Counsel to state Attorneys General throughout the United States in their investigation into the billing practices and fee structures of managed care organizations (MCOs) and PBMs in their delivery of services to state-funded health plans. To date, Cohen Milstein’s work with Attorneys General has resulted in more than $950 million in recoveries on behalf of state Medicaid programs.
Ohio Highway Patrol Retirement System v. Express Scripts, Inc.
Ohio Highway Patrol Retirement System v. Express Scripts, Inc. (Franklin C.P., Ohio): Cohen Milstein serves as Special Counsel to the Ohio Attorney General In this breach of contract litigation alleging that Express Scripts, Inc. overcharged HPRS on the pharmaceutical claims that Express Scripts processed as HPRS' PBM.
Super Lawyers Rising Star (2024, 2025)
May 16, 2026
RealPage And Most Landlords Must Face NJ’s Antitrust Claims
A New Jersey federal judge held that RealPage and most landlords accused of price-fixing must face the state attorney general's antitrust allegations.
In the News | Law360
March 12, 2026
Aaron Marks Advises on Public Interest Careers
Aaron Marks, an associate in Cohen Milstein’s Antitrust practice, will be speaking at Harvard Law School on March 12, 2026 at 9 am.
Events | Harvard Law School
September 24, 2025
AvalonBay Can’t Duck DC’s RealPage Claims
A District of Columbia Superior Court judge has rejected landlord AvalonBay Communities Inc.'s bid to escape D.C.'s rent-fixing antitrust suit against property management software company RealPage Inc., AvalonBay and several landlords.
In the News | Law360
July 25, 2025
WAV Taxis and Rideshares Open Doors for Inclusive Transportation
They say you can get anything in New York City — and that includes wheelchair-accessible vehicles (WAVs) through taxi companies and rideshare apps. However, this ridesharing access is not common, according to New York-based attorney and disability rights advocate Aaron Marks.
In the News | MDA Quest Media
June 3, 2025
Landlord To Quit Pricing Software To Escape Antitrust Suit
William C. Smith & Co. will be stepping out of litigation accusing the company of using property management platform RealPage to conspire with other landlords and fix the price of rentals in the D.C. area, after agreeing to reform its business practices and shell out over $1 million.
In the News | Law360
April 23, 2025
NJ AG Sues RealPage, Landlords, Claiming Rent Price ‘Cartel’
RealPage Inc. and 10 of New Jersey’s largest landlords are colluding to raise rents in violation of state and federal antitrust and consumer protection laws, forcing Garden State residents to overpay for housing, Attorney General Matt Platkin claimed Wednesday in a federal lawsuit.
In the News | Law360
April 1, 2025
Takeda Antitrust Trial Over Actos Generics Set for July
A New York federal court refused a bid from Takeda Pharmaceuticals Co. to escape a long-running case accusing it of unlawfully delaying generic versions of its diabetes treatment Actos and scheduled a trial to start in July.
In the News | Law360
January 2, 2025
DC Allowed To Resubmit AvalonBay Rent-Fixing Claims
The District of Columbia will get another chance to tweak its claims against landlord AvalonBay Communities and see if the changes are enough to prop up allegations that it has been using the property management platform RealPage to fix the price of rentals. AvalonBay was let out of the litigation in May, but Superior Court […]
In the News | Law360
September 6, 2024
Actelion Must Face Tracleer Antitrust Suit With Class Certified
A Maryland federal judge refused Friday to toss an antitrust suit accusing Actelion Pharmaceuticals of illegally denying generics companies the samples they needed to produce generic versions of its hypertension drug Tracleer, while separately certifying a class composed of “hundreds” of insurers and self-funded employers. U.S. District Judge George L. Russell III issued two omnibus […]
In the News | Law360
July 31, 2024
Using AI for Good: Artificial Intelligence in Shareholder Advocacy
One can hardly open the business section of a newspaper today without immediately seeing an article about Artificial Intelligence (“AI”). Companies use the term to refer to different things, but one of the most prominent and frequently discussed types of AI used in businesses today is “generative AI.” Generative AI trains AI to absorb large amounts […]
Articles | Shareholder Advocate Summer 2024
August 9, 2024
Takeda Should Face Certified Antitrust Classes, Judge Says
A New York federal judge on Friday recommended certifying two classes of direct purchasers and end payors in consolidated antitrust actions accusing Takeda Pharmaceuticals Co. of unlawfully inflating the price of its diabetes treatment Actos by delaying entry of generic alternatives. U.S. Magistrate Judge Stewart D. Aaron’s report and recommendation said both groups’ motions for […]
In the News | Law360
July 31, 2024
Summer 2024 Shareholder Advocate Released
The Summer 2024 issue of the Shareholder Advocate, our quarterly securities litigation and investor protection newsletter, features: Download the issue (PDF).
In the News | Cohen Milstein
May 2, 2024
Biologics Antitrust Litigation: An Important Tool for Employers to Recover Prescription Drug Overcharges
Antitrust litigation continues to be an important vehicle for employers, multi-employer health funds, and public entities to recover damages for inflated prices they have paid for prescription drugs through their employee benefits package. Cohen Milstein has been at the forefront of these cases, serving as lead counsel and recovering hundreds of millions of dollars for […]
Articles | Shareholder Advocate Spring 2024
May 2, 2024
Spring 2024 Shareholder Advocate is Now Available
The Spring 2024 issue of the Shareholder Advocate, our quarterly securities litigation and investor protection newsletter, features: Read the Spring 2024 issue of the Shareholder Advocate.
In the News | Cohen Milstein
March 6, 2024
Talking Careers: NYU Law Plaintiffs’ Law Association Panel
Aaron Marks, an associate in our Antitrust practice, will join a panel of practitioners from some of the country’s top plaintiff-side civil litigation firms, including Sanford Heisler, Cohen Milstein, Milberg, and Bernstein Litowitz. The NYU Law School Plaintiffs’ Law Association panel is open to all students interested in learning more about these career paths. Wednesday, March […]
Events | NYU Law School
October 20, 2023
Lessons for Biosimilar and Biologic Antitrust Litigation
The future of pharmaceutical antitrust litigation will likely focus in large part on biologics and biosimilars. Cases involving the delayed market entry of generic pharmaceuticals have traditionally focused on small-molecule generic drugs. In recent years, though, the U.S. drug market has come to be dominated by biologics. Biologics — and their generic counterparts, called biosimilars […]
Articles | Law360
November 1, 2023
DC’s AG Accuses RealPage, Landlords Of Price Fixing
The attorney general of Washington, D.C., sued RealPage and 14 D.C.-area landlords Wednesday, joining a long list of lawsuits accusing the software company of colluding to illegally use its algorithm to raise rents, violating both federal and local antitrust laws. Attorney General Brian L. Schwalb accused RealPage Inc. and the landlords of violating the Sherman […]
In the News | Law360