id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
work_jaowdmixhngcdduzjxidm6jxd4	Joseph A. DiMasi	The Economics of Follow-on Drug Research and Development	2004	14	.pdf	application/pdf	9106	942	69	We determined average times to initial and subsequent entry in drug classes by drug in a new class enjoys has fallen dramatically over time (a median of 10.2 years development prior to the approval of the class breakthrough drug. Conclusions: The data suggest that entry barriers have fallen over time for new drug However, only ten first-in-class drugs are examined covering a nearly 30-year period with no indication that steps were taken to be comprehensive, new follow-on drugs at the time of marketing compare them to the approval and development histories of their corresponding first-in-class drugs. to 1998 period that have not had chemical or pharmacological follow-on new drug approvals. Regression results for trends in the time to market entry following a first in class approval Share of therapeutic classes with at least one follow-on drug with development phase initiated prior to first-in-class approval by	./cache/work_jaowdmixhngcdduzjxidm6jxd4.pdf	./txt/work_jaowdmixhngcdduzjxidm6jxd4.txt