Academics with novel research questions can collaborate with the FDA. However, due to the confidential nature of sponsor data, all analyses are performed internally by FDA statisticians. External partners provide clinical insight and interpretation on summarized, non-confidential outputs.
The FDA receives raw and cleaned datasets from sponsors, not just summary reports. Their internal teams conduct independent analyses, which can lead to findings or data presentations in the official drug label that differ from or expand upon what's in the published paper.
A pooled FDA analysis of four major kidney cancer trials found no "magic number" or threshold for tumor shrinkage that guarantees a favorable outcome. Instead, the relationship is linear: any incremental increase in tumor reduction correlates with better 36-month overall survival.
While depth of response strongly predicts survival for an individual patient, the FDA analysis concludes it cannot yet be used as a surrogate endpoint to replace overall survival in pivotal clinical trials. It serves as a measure of drug activity, similar to response rate, but is not sufficient for drug approval on its own.
When asked if they would investigate a safety concern for a specific drug at an external party's request, the FDA expressed reluctance. Such an analysis would raise questions of bias. Instead, they prefer to address these questions by pooling data from multiple drugs with a similar mechanism of action.
An FDA analysis showed the survival curve for kidney cancer patients on IO-IO therapy (ipinevo) is much flatter for those with early tumor growth compared to IO-TKI regimens. This suggests early progression on a dual-mechanism IO-TKI therapy indicates true resistance, while on IO-IO it could be delayed response.