Net loss per share (Tables)

3 Months Ended

Mar. 31, 2018

Net loss per share

Outstanding potentially dilutive securities excluded in the calculation of diluted net loss per share

	As of March 31,
	2018	2017
Unvested restricted common stock	412,150	997,142
Shares reserved for issuance under stock plans	6,810,806	5,481,511
Total	7,222,956	6,478,653