Mr. Hasson is leader of the firm's Trial Team and co-leader of the Litigation Practice. His practice includes a range of litigation, including disputes regarding intellectual property rights, often in the technology and life sciences fields; internal investigations; shareholder and securities actions; contract disputes, often regarding licensing and collaboration agreements; claims of fiduciary liability; and appeals. In these areas, he has prosecuted and defended numerous state and federal trial court and arbitration cases and appeals as lead counsel, and led numerous internal investigations.

Mr. Hasson has been recognized by Chambers USA as a Tier 1 lawyer in California regarding IP and patent litigation, named a Northern California "Super Lawyer" and listed as a recommended attorney in life sciences in the U.S. by Practical Law Company's Which Lawyer?

• XOMA Ltd. v. Biosite Incorporated (U.S. District Court cases, N.D. Cal.) - Actions regarding purported termination of license to patents regarding modular assembly of antibodies
• Immunex Corporation and Amgen Inc. v. Trustees of Columbia University and related action (U.S. District Courts, C.D. Cal. and D. Mass. (MDL case) ) - Action regarding rights under license to Axel patents regarding cotransformation of mammalian cells to produce proteins of interest
• Elan Pharmaceuticals v. Eli Lilly (U.S. District Court, N.D. Cal.) - Action to establish rights of ownership to promising vaccine for Alzheimer’s disease
• Immune Response Corporation v. Rhone-Poulenc Rorer (AAA arbitration, Chicago) - Arbitration to establish rights of ownership and control of Jonas Salk’s AIDS vaccine
• Regents of the University of California v. Agouron Pharmaceuticals, Inc. (later, Pfizer Inc) (California Superior Court) - Action to resolve dispute regarding royalty base under license agreement regarding material used to make protease inhibitor
• Artes Medical USA, Inc. v. BioForm Medical, Inc. (U.S. District Court, S.D. Cal.; California Superior Court; Regional Court, Patent Panel, Frankfurt, Germany) - Actions to determine rights under option and license agreement for patent regarding medical device implant materials
• Rehabilitation Technologies, Inc. v. Smith Laboratories (California Superior Court and Court of Appeal) - Action challenging failure to close on sale of medical device company
• Confidential ICC Arbitration between major pharmaceutical companies - Action to determine ownership, trade secrets and enforcement rights regarding biotechnology materials and related patents
• Confidential AAA Arbitration for major medical device manufacturer - Action to determine royalty base for license relating to cardiac medical device technology

• XOMA Ltd. v. Biosite Incorporated (US District Court, N.D. Cal.) - Action regarding alleged infringement of patents regarding modular assembly of antibodies
• Immunex Corporation and Amgen Inc. v. Trustees of Columbia University and related action (U.S. District Courts, C.D. Cal. and D. Mass. (MDL case) ) - Action to declare invalid, unenforceable or non-infringed Axel patents regarding cotransformation of mammalian cells to produce proteins of interest
• Hoffman-La Roche, Inc. v. Promega Corporation (U.S. District Court, N.D. Cal.) - Action alleging infringement and counterclaims to declare invalidity or unenforceability of patents relating to polymerase chain reaction
• Artes Medical USA, Inc. v. BioForm Medical, Inc. (U.S. District Court, S.D. Cal.; California Superior Court; Regional Court, Patent Panel, Frankfurt, Germany) - Actions alleging infringement of U.S. and E.U. patents regarding medical implant materials
• General Surgical Innovations v. Origin Medsystems, Inc. (subsidiary of Guidant) (U.S. District Court, N.D. Cal.) - Action where, following determination of infringement, we were asked to obtain and did obtain substantial deferment of injunctive relief based on public interest

• Campagnuolo v. IDEC Pharmaceuticals (U.S. District Court, S.D. Cal.) - Action challenging merger of IDEC Pharmaceuticals and Biogen
• Klein v. Salvi (S.D.N.Y.) - 16(b) case challenging merger values delivered to officers and shareholders of major generic pharmaceutical company who were also officers and shareholders of acquired biotech company
• Equity-Linked Investors v. Adams (Delaware Chancery Court) - Action challenging actions of directors of Genta regarding stock offering said to undervalue corporate assets regarding biotechnology company active in antisense field

• County of Santa Clara v. Astra et al. (U.S.District Court, N.D.Cal.) – Purported Class action challenging alleged industry practices regarding pricing to “Section 340B” qualified entities
• In re Pharmaceutical Industry Average Wholesale Pricing Litigation (Sicor) (U.S. District Courts (several) and MDL in D. Mass.) - Class actions challenging alleged industry practices regarding average wholesale price reporting
• State of California ex rel. Richardson v. IREF et al. (Sicor) (California Superior Court) - Qui tam action challenging underpayments allegedly made to the University of California by a foundation and pharmaceutical developers
• Chiron v. SourceCF (U.S. District Court, N.D. Cal.) - Action alleging marketing of unsafe medical device for use in combination with drugs for treatment of CF