Background: Food and Drug Administration (FDA) advisory committees are essential in the process to market new drugs or authorize a new indication for an approved drug. Methods: This review of 2004 FDA advisory committee meetings analyzes questions posed to panel experts, results of experts votes, and regulatory actions taken by the agency. Results: Thirteen proposed indications concerning 10 new drugs were reviewed. Oncologic drugs covered six indications. While efficacy questions were the most frequent, safety questions were the most challenging. Beyond a statistical significance, sponsors were regularly asked to demonstrate the clinical relevance of study results. This sometimes proved unsuccessful for oncology indications. An identified safety signal could be problematic if the risk of the adverse reaction for an individual patient is not properly defined or if the adverse reaction cannot be minimized. Potential safety concerns are frequently raised but are difficult to address within the current regulatory guidance as such a risk cannot be objectively defined or prevented. The risk benefit analysis of advisory panels frequently contradicted sponsors analysis. Only 4 of the 13 proposed indications presented were later approved by the FDA. Conclusion: A better understanding of the conflicting opinions between advisory experts and sponsors will improve the conduct and review of clinical programs aiming at new indications.