Aurinia Pharmaceuticals faced significant market turbulence after a senior FDA official publicly questioned the clinical value of the company's lupus nephritis drug Lupkynis (voclosporin), sparking broader concerns about regulatory reliance on surrogate endpoints for drug approvals.
George Tidmarsh, director of the FDA's Center for Drug Evaluation and Research (CDER), criticized Lupkynis in a LinkedIn post, stating that the agency has "approved drugs with significant toxicity like voclosporin that has not been shown to provide a direct clinical benefit for patients." The comments sent Aurinia shares tumbling 16.4% in afternoon trading.
Regulatory Scrutiny of Surrogate Endpoints
Tidmarsh's criticism extended beyond Lupkynis to broader concerns about surrogate endpoint usage in drug approvals. "CDER will be evaluating surrogate endpoints used for FDA approval," he wrote, noting that while such endpoints have benefited patients by bringing treatments to market sooner, there have been "notable failures in confirmatory trials."
The FDA director specifically highlighted lupus nephritis as a disease area where "companies have not run trials to demonstrate a benefit on hard clinical endpoints like progression to end stage renal disease." This represents a significant shift in regulatory thinking, as surrogate endpoints have been widely used to accelerate drug approvals in areas of high unmet medical need.
Lupkynis Approval and Clinical Data
The FDA approved Lupkynis in 2021 for treating lupus nephritis patients based on pivotal data demonstrating a significant decline in urine protein creatinine ratio, a measure of protein levels in the kidney. Aurinia's clinical data showed that patients treated with Lupkynis plus standard of care were more than twice as likely to see renal response compared to placebo.
The drug carries a boxed warning for malignancies and serious infections, reflecting the significant safety concerns Tidmarsh referenced in his criticism. Despite these warnings, the FDA had previously updated Lupkynis's label in April 2024 with three-year data from the AURORA 2 extension study, confirming higher sustained complete renal response rates versus placebo.
Unusual Public Criticism and Industry Connections
Tidmarsh's public criticism of an approved drug represents highly unusual behavior for a senior FDA official. The director subsequently deleted his LinkedIn posts and issued a clarification stating that his comments "were my own personal views" and "do not reflect the views of the FDA or Department of Health and Human Services."
The situation carries additional complexity due to historical connections between Tidmarsh and Aurinia's leadership. Kevin Tang, chairman of Aurinia's board of directors and the company's largest shareholder through Tang Capital Management, previously worked with Tidmarsh at La Jolla Pharmaceuticals, where Tang served as chairman and major shareholder while Tidmarsh was CEO.
Market Impact and Regulatory Implications
The market's sharp reaction to Tidmarsh's comments underscores investor sensitivity to regulatory criticism of approved therapies. Aurinia shares closed down 15.8% on Monday, reflecting concerns about potential regulatory action or reputational damage to Lupkynis.
The broader implications for the pharmaceutical industry remain unclear, as CDER's stated intention to reevaluate surrogate endpoint usage could affect future drug approvals across multiple therapeutic areas. The agency's approach to balancing accelerated approvals with confirmatory evidence requirements will likely face increased scrutiny from both industry stakeholders and patient advocacy groups.
