Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2019

Goodwill And Intangible Assets Disclosure [Abstract]

Summary of Intangible Assets

Intangible assets are related to certain capitalized milestone and sublicense payments. The following table presents intangible assets (in thousands):

	March 31, 2019			December 31, 2018
Intangible assets	$	19,773		$	19,773
Less accumulated amortization		(10,328	)		(8,056	)
Total	$	9,445		$	11,717