The following table contains selected quarterly financial information for 2017 and 2016. The Company believes that the following information reflects all normal recurring adjustments necessary for a fair statement of the information for the periods presented. The operating results for any quarter are not necessarily indicative of results for any future period.

	Three Months Ended
	March 31, 2017			June 30, 2017			September 30, 2017			December 31, 2017
Revenue	$	—		$	—		$	—		$	—
Operating expenses:
Research and development		2,942			3,161			3,825			4,311
General and administrative		1,647			1,791			2,601			2,730
Total operating expenses		4,589			4,952			6,426			7,041
Loss from operations		(4,589	)		(4,952	)		(6,426	)		(7,041	)
Interest income		32			29			167			176
Net loss		(4,557	)		(4,923	)		(6,259	)		(6,865	)
Accretion of redeemable convertible preferred stock to redemption value		(20	)		(21	)		—			—
Net loss attributable to common stockholders	$	(4,577	)	$	(4,944	)	$	(6,259	)	$	(6,865	)
Net loss per share attributable to common stockholders—basic and diluted	$	(10.58	)	$	(10.98	)	$	(0.45	)	$	(0.47	)
Weighted average common shares outstanding—basic and diluted		432,728			450,495			13,939,950			14,720,734
Comprehensive loss:
Net loss	$	(4,557	)	$	(4,923	)	$	(6,259	)	$	(6,865	)
Other comprehensive loss:
Unrealized loss on investments, net of tax of $0		—			—			(6	)		(27	)
Total other comprehensive loss		—			—			(6	)		(27	)
Total comprehensive loss	$	(4,557	)	$	(4,923	)	$	(6,265	)	$	(6,892	)

	Three Months Ended
	March 31, 2016			June 30, 2016			September 30, 2016			December 31, 2016
Revenue	$	—		$	—		$	—		$	—
Operating expenses:
Research and development		2,493			2,086			2,605			3,092
General and administrative		1,446			3,464			1,627			1,356
Total operating expenses		3,939			5,550			4,232			4,448
Loss from operations		(3,939	)		(5,550	)		(4,232	)		(4,448	)
Interest income		14			16			10			6
Net loss		(3,925	)		(5,534	)		(4,222	)		(4,442	)
Accretion of redeemable convertible preferred stock to redemption value		(18	)		(19	)		(19	)		(19	)
Net loss attributable to common stockholders	$	(3,943	)	$	(5,553	)	$	(4,241	)	$	(4,461	)
Net loss per share attributable to common stockholders—basic and diluted	$	(9.25	)	$	(12.95	)	$	(9.84	)	$	(10.31	)
Weighted average common shares outstanding—basic and diluted		426,487			428,870			430,929			432,413
Comprehensive loss:
Net loss	$	(3,925	)	$	(5,534	)	$	(4,222	)	$	(4,442	)
Other comprehensive loss:
Unrealized loss on investments, net of tax of $0		7			(5	)		(3	)		1
Total other comprehensive loss		7			(5	)		(3	)		1
Total comprehensive loss	$	(3,918	)	$	(5,539	)	$	(4,225	)	$	(4,441	)