Summary of significant accounting policies (Tables)

9 Months Ended

Sep. 30, 2019

Summary of significant accounting policies

Schedule of potentially dilutive securities excluded from calculation of diluted net loss per share

The following table sets forth the potentially dilutive securities that have been excluded from the calculation of diluted net loss per share because to include them would be anti‑dilutive (in common stock equivalent shares):

	Nine Months Ended
	September 30,
	2019	2018
Series A convertible preferred stock	612,446	612,446
Series B convertible preferred stock	7,235,969	7,235,969
Series C convertible preferred stock	5,179,877	—
Options to purchase common stock	2,970,234	1,844,990
Total shares of common stock equivalents	15,998,526	9,693,405