FDA's CDER Director Sparks Controversy Over Surrogate Endpoints in Drug Approvals

The pharmaceutical industry is abuzz following comments made by Dr. George Tidmarsh, director of the FDA's Center for Drug Evaluation and Research (CDER), questioning the reliance on surrogate endpoints for drug approvals. In a now-deleted LinkedIn post, Tidmarsh singled out Aurinia Pharmaceuticals' lupus nephritis drug Lupkynis as an example of the potential shortcomings of this approach.

Tidmarsh's Critique and Its Implications

Tidmarsh's post claimed that the FDA has "approved drugs with significant toxicity like vocolosporin [Lupkynis' active ingredient] that has not been shown to provide a direct clinical benefit for patients." He further alleged that "for some diseases such as lupus nephritis, companies have not run trials to demonstrate a benefit on hard clinical endpoints."

These statements have raised concerns about the FDA's approval process and the use of surrogate endpoints in clinical trials. Surrogate endpoints are often used as substitutes for clinical outcomes in drug studies, allowing for faster approvals based on markers that are believed to predict clinical benefit.

Aurinia Pharmaceuticals and Lupkynis

Aurinia Pharmaceuticals, the company behind Lupkynis, saw its stock price drop 15.8% at market close on Monday following Tidmarsh's comments. The FDA approved Lupkynis in 2021 for the treatment of lupus nephritis, based on data showing a significant decline in urine protein creatinine ratio, a measure of protein levels in the kidney.

The drug's approval was supported by pivotal data demonstrating that patients treated with Lupkynis plus standard of care were more than twice as likely to see renal response. However, Tidmarsh's comments suggest that this surrogate endpoint may not necessarily translate to direct clinical benefits for patients.

Industry Connections and Potential Conflicts

Adding another layer to this story are the industry connections between Tidmarsh and key figures at Aurinia. Kevin Tang, chairman of Aurinia's board of directors, is well-known in the biotech industry for his company Concentra Biosciences, which acquires struggling biotechs. Tang Capital Management, led by Kevin Tang, is Aurinia's largest shareholder.

Interestingly, Tidmarsh and Tang have a shared history at La Jolla Pharmaceuticals, where Tang was chairman and major shareholder, and Tidmarsh served as CEO until stepping down in November 2019. The reasons for Tidmarsh's departure from La Jolla remain unclear, with the company only stating at the time that he wanted to "pursue other interests."

These connections have led some industry observers to question whether personal history may have influenced Tidmarsh's public comments about Aurinia's drug.