While proposals to create "progressive" approval pathways have been in the spotlight, a movement to create a "staged" approval pathway is gaining momentum in Washington. The idea would permit abbreviated development of therapies for well-defined populations with serious unmet medical needs while limiting off-label use.

The concept has emerged as a tool to speed the development of therapies for multi-drug resistant pathogens. But its supporters envision a much wider application to include conditions - such as obesity - in which the sickest patients are unable to get new drugs because regulators are unwilling to expose larger, healthier populations, or patients with acceptable therapeutic options, to known or potential adverse effects.