Redeemable Convertible Preferred Stock Tranche Liability

12 Months Ended

Dec. 31, 2020

Temporary Equity Disclosure [Abstract]

Redeemable Convertible Preferred Stock Tranche Liability

14. Redeemable Convertible Preferred Stock Tranche Liability

The Company determined that the obligations to issue additional shares of Series A redeemable convertible preferred stock at the Milestone Closing and Additional Closing were freestanding instruments that are required to be accounted as a liability initially recorded and subsequently remeasured at fair value until such instruments are exercised or expire. The Milestone Closing liability and Additional Closing liability were initially recorded at $6.2 million and $5.0 million, respectively.

The Milestone Closing liability was settled in November 2018 upon the Milestone Closing and the related TRDF liability was settled in March 2019. In July 2019, as part of the Series B redeemable convertible preferred stock purchase agreement the Additional Closing liability and the related TRDF liability were terminated. The Company recorded $2.0 million gain from the remeasurement of the redeemable convertible preferred stock tranche liability in other income (expense), net in its consolidated statements of operations and comprehensive loss during the years ended December 31, 2019.

The Additional Closing liability was valued using the following assumptions under the option-pricing method:

	Fair Value of Series A Preferred Stock		Term	Interest rate			Volatility
December 31, 2018	$	10.48	1.88 years		2.50	%		69.80	%
July 25, 2019	$	7.18	1.31 years		1.95	%		69.10	%