Related-Party Transactions - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Patent No. 8,420,051 [Member]
Related Party Transaction [Line Items]
Expected patent expiration year	2029
Consulting Agreement [Member]
Related Party Transaction [Line Items]
Consulting agreement fees paid to Prof. Dr. Skerra		$ 6,000
TUM [Member]
Related Party Transaction [Line Items]
Patent expiration year	2027
Total expenses	$ 0	$ 14,000