Condensed consolidated statements of operations and comprehensive (loss) income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue (Note 8)		$ 25,000		$ 25,000
Operating expenses
Research and development (Note 7)	$ (1,995)	17,996	$ (1,891)	28,504
General and administrative (Note 7)	2,423	4,314	4,978	8,623
Total operating expenses	428	22,310	3,087	37,127
(Loss) income from operations	(428)	2,690	(3,087)	(12,127)
Other income, net (Note 9)	427	228	878	422
Net (loss) income	$ (1)	$ 2,918	$ (2,209)	$ (11,705)
Net (loss) earnings per common stock (Note 10)
Basic		$ 0.12	$ (0.09)	$ (0.50)
Diluted		$ 0.12	$ (0.09)	$ (0.50)
Weighted average number of common stock outstanding (Note 10)
Basic	23,537,368	23,521,719	23,537,368	23,501,351
Diluted	23,537,368	23,846,256	23,537,368	23,501,351
Comprehensive (loss) income:
Net (loss) income	$ (1)	$ 2,918	$ (2,209)	$ (11,705)
Other comprehensive income - unrealized gain on available-for-sale securities		22		68
Comprehensive (loss) income	$ (1)	$ 2,940	$ (2,209)	$ (11,637)