An ad hoc committee will plan and conduct a public workshop, whose agenda will address the promises and challenges involved in the development of combination investigational therapies. The workshop, which will feature invited presentations and discussion, will identify obstacles that may be preventing different sponsors from collaborating to develop novel agents as combination therapies, such as scientific, clinical, and regulatory issues, as well as organizational culture and intellectual property issues. Workshop participants will also discuss potential ways to facilitate these collaborations in the future. An individually-authored summary of the workshop will subsequently be prepared by a designated rapporteur.