Mark S. Cheffo

• A major pharmaceutical company as national counsel in an MDL and state-court litigation involving the claim that an H2 receptor antagonist caused patients to develop cancer. Mr. Cheffo served as Co-Lead Counsel for Defendants in the MDL.
• A major pharmaceutical company as national counsel in an MDL involving over 3,000 plaintiffs and allegations that one of the company’s medications caused women to develop diabetes. Successfully excluded plaintiffs’ causation experts and won summary judgment in all MDL cases; argued the appeal in the U.S. Court of Appeals for the Fourth Circuit, which unanimously affirmed.
• A major pharmaceutical company as national counsel in an MDL and related state cases involving allegations that in utero exposure to an antidepressant medication caused children to develop birth defects. Successfully excluded the MDL plaintiffs’ general causation experts and obtained summary judgment for all MDL cases; argued the appeal before the U.S. Court of Appeals for the Third Circuit, which unanimously affirmed.
• Several pharmaceutical companies in securing a complete dismissal in multidistrict litigation in connection with personal injury claims arising from the manufacturing and distribution of generic prescription medications containing propoxyphene.
• A client in successfully arguing a motion to dismiss a consolidated nationwide consumer fraud class action complaint in an MDL and also argued the appeal in the Ninth Circuit, where the district court’s decision was affirmed.
• A major biotechnology company in multidistrict litigation involving a nationwide consumer fraud action.
• Several major pharmaceutical companies in connection with the development of risk management initiatives, labelling advice and document management.
• One of the world’s largest computer manufacturers in class actions challenging alleged product defects.
• Individual and corporate property owners in connection with more than 70 cases alleging pediatric brain injuries from exposure to environmental toxins.

Includes matters handled at Dechert or prior to joining the firm.

Dechert’s Product Liability and Mass Torts practice represents multinational companies in complex, high-stakes product liability, toxic tort, consumer class action, and government plaintiff litigation. With more than four decades of experience, the team frequently serves as lead or coordinating counsel in major state and federal proceedings, including multidistrict litigation and other large-scale, cross-jurisdictional matters.

The practice combines trial capability with substantial scientific, appellate, and industry experience. Its approximately 70-member team includes first-chair trial lawyers, science-focused practitioners, and appellate specialists who work together on issues ranging from early case assessment and dispositive motions through bellwether trials, appeals, settlement strategy, and nationwide litigation management.

Dechert has handled some of the country’s largest federal MDLs and other mass tort proceedings, including matters involving pharmaceuticals, medical products, consumer products, and toxic exposure claims. The firm has obtained pretrial dismissals of entire MDLs, successfully defended those rulings on appeal, and served as lead trial counsel in significant bellwether and other high-profile proceedings.

The team also has extensive experience managing litigation involving novel legal and scientific questions, class actions, and parallel claims across multiple jurisdictions. Its approach combines coordinated case strategy with deep subject-matter experience to help clients manage both the immediate litigation and the broader legal and commercial risks surrounding major product liability disputes.

Founded in 1875, Dechert LLP is an international law firm with offices across the United States, Europe, Asia, and the Middle East. The firm advises corporations, financial institutions, investment managers, private equity firms, life sciences companies, and other organizations on sophisticated transactional, regulatory, and contentious matters.

Dechert’s principal capabilities include corporate and M&A, private equity, financial services and investment management, finance, litigation, international arbitration, antitrust, restructuring, real estate, intellectual property, tax, labor and employment, white-collar investigations, product liability, and private client work. The firm is particularly well established in investment funds and asset management, while also maintaining significant practices in private equity, life sciences, financial services, and complex disputes.

The firm operates on an integrated international basis, with lawyers across its offices collaborating on matters involving multiple jurisdictions and regulatory regimes. Dechert combines industry knowledge with multidisciplinary legal capabilities, supporting clients on major transactions, investigations, disputes, financings, regulatory challenges, and long-term strategic matters.