Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2018

Fair Value Disclosures [Abstract]

Schedule of fair value on a recurring basis by level of fair value hierarchy

The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy:

	September 30, 2018
	Level 1		Level 2		Level 3		Total
Financial Assets:
Money market funds	$	21	$	—	$	—	$	21
Corporate fixed income debt securities		—		2,448		—		2,448
Total	$	21	$	2,448	$	—	$	2,469
Financial Liabilities:
Common stock warrant liability (1)	$	—	$	—	$	—	$	—
Total	$	—	$	—	$	—	$	—
	December 31, 2017
	Level 1		Level 2		Level 3		Total
Financial Assets:
Money market funds	$	3	$	—	$	—	$	3
Corporate fixed income debt securities		—		5,023		—		5,023
Total	$	3	$	5,023	$	—	$	5,026
Financial Liabilities:
Common stock warrant liability (1)	$	—	$	—	$	—	$	—
Total	$	—	$	—	$	—	$	—

(1) The change in the fair value of the common stock warrant and convertible notes payable for the three and nine months ended September 30, 2018 was recorded as a decrease to other income (expense) and interest expense of $1 and $1, respectively, in the statements of operations and comprehensive loss.