	Nearly all later entrants to drug classes had begun clinical testing or were in regulatory review in the United States before the first drug within a pharmacologic class was approved, a newly completed analysis from the Tufts Center for the Study of Drug Development suggests.

	The analysis looked at 40 pharmacologic classes and included drugs and biologics between the 2005 - 2011 period, where 90% of all later-in-class drugs had at least initiated Phase I clinical testing anywhere in the world or had filed an investigational new drug application with the U.S. Food and Drug Administration (FDA) before FDA approval for the first-in-class drug, according to Tufts CSDD.

	Key findings from the studies, reported in the November/December 

			83% of all later-in-class drugs had at least initiated Phase II clinical testing abroad or in the U.S. prior to U.S. marketing approval for the first-in-class drug.

			All later-in-class drugs had a patent filed somewhere in the world before the first-in-class drug was approved in the United States; 96% had a U.S. patent filed before first-in-class approval.

			More than half of all later-in-class drugs received a 'priority rating' from the FDA.