When are primary trial results required to be posted on a clinical trial registry site in the US?

The correct answer is that primary trial results are required to be posted on a clinical trial registry site in the US within 12 months of market approval or after the last patient's visit. This requirement aligns with the regulations set forth by the FDA Amendments Act (FDAAA) of 2007, which mandates that results of certain clinical trials be shared publicly to ensure transparency and accessibility of clinical data.

Posting results within this time frame helps fulfill the objective of enhancing public knowledge about the safety and efficacy of treatments that have undergone testing in clinical trials. It also empowers healthcare professionals, patients, and researchers with valuable information that can inform treatment decisions and future research directions.

In contrast, while trial results can be posted after approval to market, this does not ensure they are publicly available while there is ongoing clinical interest or post-market monitoring. Posting immediately after trial completion may not consider the necessary aftermath of analyses and finalizations required for comprehensive reporting. Additionally, posting at the end of the enrollment period does not provide the full context of the trial's findings, which might only be finalized after the last patient has completed their participation and the study has been fully analyzed.

Thus, the requirement to post results within 12 months of market approval or after the last patient's visit appropriately