Key Takeaways

  • The California Supreme Court rejected a novel negligence theory that would have let plaintiffs sue manufacturers over nondefective products for not developing a “better” alternative sooner.
  • Gilead reaffirms California’s defect-centered framework for negligence claims against product manufacturers, and its reasoning gives manufacturers across industries—not just pharmaceutical products—strong precedent for rejecting “failure-to-innovate” theories premised on delayed development of a safer alternative product. 

In Gilead Tenofovir Cases, the California Supreme Court held that drug manufacturers do not owe a duty of care to users of a nondefective drug when deciding whether and when to develop and market a potentially safer alternative. We previously covered Gilead’s appeal of lower court decisions permitting novel negligence claims to proceed in a 23,000 case coordinated proceeding. In a 6-1 decision on August 3, 2026, the California Supreme Court reversed and rejected a “duty-to-innovate” theory of negligence that threatened to reshape product liability exposure.

Plaintiffs alleged injuries from their use of Gilead’s tenofovir disoproxil fumarate (“TDF”), an HIV medication. Plaintiffs conceded that the drug was not defective; instead, they claimed that Gilead negligently delayed developing tenofovir alafenamide (“TAF”), an alternative drug they alleged was equally effective and safer. The court reaffirmed that a manufacturer’s duty of care is generally “limited to designing, manufacturing, and marketing products that are free from defects,” and it held that plaintiffs’ theory of liability “lacks a clear limiting principle.”

Rather than decide whether a broader duty of care could ever exist, the majority held that California’s Rowland v. Christian factors required an exception to such a duty. 69 Cal.2d 108 (1968). The court held that the alleged harm was unforeseeable in the context of drug development and the causal chain was too speculative. It also held that the proposed duty could chill innovation by discouraging research into alternative drug candidates.

The case’s significance extends across industries. More than 70 amici weighed in, and the court’s reasoning expressly expands beyond pharmaceutical products. It noted that accepting plaintiffs’ negligence theory “could have far-reaching consequences across a broad range of industries.”

Gilead makes clear that manufacturers owe no duty to innovate and reaffirms that a defect remains the touchstone of product liability claims.