Background
I.F. and P.S. brought a proposed class proceeding against Gilead Sciences, Inc. and Gilead Sciences Canada Inc. concerning tenofovir disoproxil fumarate (TDF), a compound used in HIV medicines. They alleged that TDF posed kidney, bone, and tooth risks and that Gilead knew of a safer, economically feasible alternative—tenofovir alafenamide fumarate (TAF)—but delayed its development to maximize profits from TDF products.
TDF was approved in Canada in 2003 and remains approved and widely used. Gilead began researching TAF in 1998, paused active development after early clinical trials, resumed it in 2010, and obtained approvals for TAF drugs between 2015 and 2018. The plaintiffs did not allege inadequate warnings or contend that TDF lacked regulatory approval.
The Supreme Court of British Columbia certified the proceeding and dismissed Gilead’s Rule 9-6 summary judgment application. Gilead appealed only the refusal to summarily dismiss the negligent-design claim, arguing that such a claim required an allegation that TDF should never have been marketed and that TAF was not an available alternative when TDF was approved.
The Court’s Holding
The Court of Appeal unanimously dismissed the appeal. It held that the chambers judge correctly applied the negligent-design framework from Ding v. Canam Super Vacation Inc. The relevant question was not whether TDF was wholly defective or should never have been marketed, but whether Gilead marketed a product with a design defect creating a substantial risk of harm while knowing of a safer, economically feasible alternative, assessed through a risk-utility analysis.
The Court also upheld the finding of a genuine issue for trial. Conflicting evidence about the relative safety and efficacy of TDF and TAF, Gilead’s knowledge, and its reasons for delaying TAF development required a fuller evidentiary assessment after discovery. Regulatory approval and industry standards were relevant but not determinative of negligent-design liability.
The alternative-design inquiry was not confined to 2003, when TDF first received Canadian approval. Because medicines can be replaced as scientific knowledge develops, the analysis may examine how Gilead’s knowledge changed over time, including its decisions to halt TAF development in 2004 and restart it in 2010. The Court did not decide the merits or find Gilead liable.
Key Takeaways
- A negligent-design claim need not allege that the challenged product was wholly defective or should never have been marketed.
- Regulatory approval and continued beneficial use do not necessarily defeat negligent-design liability; they are factors in the risk-utility analysis.
- For pharmaceuticals, the safer-alternative inquiry may extend beyond initial approval and account for the manufacturer’s evolving knowledge.
- Conflicting evidence requiring a complex risk-utility assessment ordinarily cannot be resolved through British Columbia’s limited Rule 9-6 summary judgment procedure.
Why It Matters
The decision permits a novel pharmaceutical negligent-design theory to proceed: that a manufacturer may have breached its duty by delaying development of a known safer alternative even though the existing medicine was approved, effective, appropriately warned, and remained on the market.
The ruling does not establish liability or require manufacturers to replace an approved drug whenever another compound enters development. It holds only that the pleaded theory was legally viable and that the evidence was too contested and incomplete for summary dismissal.