Warrants to Purchase Convertible Preferred Stock	9 Months Ended
Sep. 30, 2019
Warrants And Rights Note Disclosure [Abstract]
Warrants to Purchase Convertible Preferred Stock	9. Warrants to Purchase Convertible Preferred Stock The Company issued warrants to purchase convertible preferred stock in 2013 and 2014 for the purchase of 375,000 shares of Series B Preferred Stock. Upon the closing of the IPO in July 2018, these warrants became warrants to purchase 34,062 shares of common stock at which time the Company reclassified the carrying value of the warrants to additional paid-in capital. Prior to the warrants becoming warrants to purchase common stock, the Company was required to remeasure the fair value of the liability for these preferred stock warrants at each reporting date since their grant date, with any adjustments recorded in interest expense. The warrants outstanding at each reporting date were remeasured using the Black-Scholes option-pricing model, and the resulting change in fair value was recorded in interest expense in the Company’s statements of operations and comprehensive loss.

Warrants to Purchase Convertible Preferred Stock

9 Months Ended

Sep. 30, 2019

Warrants And Rights Note Disclosure [Abstract]

Warrants to Purchase Convertible Preferred Stock

9. Warrants to Purchase Convertible Preferred Stock

The Company issued warrants to purchase convertible preferred stock in 2013 and 2014 for the purchase of 375,000 shares of Series B Preferred Stock. Upon the closing of the IPO in July 2018, these warrants became warrants to purchase 34,062 shares of common stock at which time the Company reclassified the carrying value of the warrants to additional paid-in capital.

Prior to the warrants becoming warrants to purchase common stock, the Company was required to remeasure the fair value of the liability for these preferred stock warrants at each reporting date since their grant date, with any adjustments recorded in interest expense. The warrants outstanding at each reporting date were remeasured using the Black-Scholes option-pricing model, and the resulting change in fair value was recorded in interest expense in the Company’s statements of operations and comprehensive loss.