The Perils of Pharmaceutical Innovation:The Surreal Tale of TDF and TAF
This Article intervenes to correct a major error in the law of products liability that is working its way through the California court system. In the Gilead Tenofovir Cases now before the California Supreme Court, the Court of Appeals allowed the case to reach a jury on the theory that in 2004, Gilead withheld development of a new product, TAF, in order to protect its monopoly position in an earlier product, TDF, which launched with great success in 2001. Gilead had adequately warned that TDF in a small number of cases produced adverse effects to kidneys and bone. The plaintiffs’ theory asserted falsely that it was clear that TAF was both safer and more efficient than TDF and would drive it off the market with an early release. But both TDF and TAF remain top-rated drugs in wide use with overlapping but distinct advantages, as they compete with each other and with antivirals from other companies. A close look at the antitrust, patent, and tort theories underlying the plaintiffs’ claims highlights the implausibility of the claims and the deep conceptual errors in the creation of this new and dangerous tort duty—including its supposed reliance on Section 1714 of the state’s Civil Code, which has never been applied to product liability cases or to mandate an untethered tort duty to investigate new drugs that the patent holder did not at the time think worthy of further research and development. Allegations of product hopping, fraud, and negligence all wither under scrutiny. To allow this case to proceed to trial creates the prospect that highly successful drugs that meet all FDA standards can produce catastrophic losses for the companies that produce them, which works against the interests of patients and health care providers alike.
Cite as Richard A. Epstein, The Perils of Pharmaceutical Innovation: The Surreal Tale of TDF and TAF, 18 N.Y.U. J.L. & Liberty 452 (2025).