Components of Net Loss Per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended		151 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013
Numerator
Net loss arising during the development stage	$ (3,215)	$ (2,753)	$ (2,754)	$ (2,464)	$ (2,101)	$ (2,269)	$ (1,541)	$ (1,612)	$ (11,186)	$ (7,523)	$ (96,297)
Denominator
Weighted average common shares outstanding									10,160,835	2,247,709
Basic and diluted net loss per share	$ (0.19)	$ (0.18)	$ (0.50)	$ (0.70)	$ (0.71)	$ (0.93)	$ (0.78)	$ (1.01)	$ (1.10)	$ (3.35)