California Supreme Court hands Gilead landmark victory in HIV drug innovation case

California's highest court has ruled in favor of Gilead Sciences (GILD), dismissing negligence claims brought by an estimated 24,000 HIV patients in a closely watched case that tested whether drugmakers can be held liable for failing to develop safer alternatives to treatments already deemed effective.

In a 6-1 decision, the California Supreme Court ordered the litigation dropped, rejecting the patients' argument that Gilead had an obligation to accelerate development of a successor drug with fewer side effects. Justice Joshua Groban, writing for the majority, said the ruling declined to establish "sweeping liability for injuries caused by a concededly nondefective drug because the manufacturer allegedly failed to make a different drug available sooner," warning that such a precedent would create substantial burdens and risk adverse consequences for pharmaceutical innovation, public health, and patient safety.

Gilead welcomed the outcome. "Today's decision is a victory for all those working to develop improved medical treatments and new medicines," the company said in a statement. "The California Supreme Court's decision supports American innovation, allowing companies to continue pursuing breakthroughs for patients and consumers."

The case centered on Gilead's HIV drugs made with tenofovir disoproxil fumarate, or TDF, which received US approval in 2001 but carried possible side effects including kidney dysfunction and bone loss. The Foster City, California-based company subsequently began testing tenofovir alafenamide fumarate, or TAF — a closely related compound with a more favorable side-effect profile — but halted that program in 2004, concluding the improvement was insufficient to justify the cost.

Patients alleged that Gilead deliberately delayed TAF's commercialization by nearly a decade to protect profits from TDF, timing its eventual launch to coincide with TDF's patent exclusivity expiring in 2017. During oral arguments in May, patients' counsel Holly Boyer argued Gilead was "willing to accept the suffering of tens of thousands of patients with HIV forced to endure a drug that was destroying their kidneys and breaking their bones" in pursuit of an additional $27bn in revenue.

Gilead's attorney, Joshua Rosenkranz, countered that the company prioritized TDF because it achieved what he described as the "holy grail" of once-daily dosing that saved millions of lives.

The pharmaceutical industry had followed proceedings closely, with the central question — whether manufacturers of approved, non-defective drugs must develop and commercialize potentially safer alternatives, a concept critics termed a "duty to innovate" — seen as having far-reaching implications. Opponents of such a standard argued it would render drug development prohibitively expensive, cap returns on successful treatments, and ultimately deprive patients of therapies that work.

HIV drugs represent a critical pillar of Gilead's business, accounting for 70 per cent of the company's $29.4bn in revenue in 2025.