Common stock (Details) - $ / shares	Dec. 31, 2024	Dec. 31, 2023	Oct. 31, 2015
Class of Stock [Line Items]
Common Stock, Shares Authorized	120,000,000	120,000,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Shares available for future issuance (in shares)	16,226,436	14,550,002
2015 Stock Option Plan
Class of Stock [Line Items]
Shares available for future issuance (in shares)	3,765,132	3,572,195	1,311,812
2015 Employee Stock Purchase Plan.
Class of Stock [Line Items]
Shares available for future issuance (in shares)	2,010,897	2,158,966
Employee Stock Option [Member]
Class of Stock [Line Items]
Shares available for future issuance (in shares)	8,800,464	7,425,444
Unvested restricted common stock units
Class of Stock [Line Items]
Shares available for future issuance (in shares)	1,649,943	1,370,897
Founders restricted stock
Class of Stock [Line Items]
Shares available for future issuance (in shares)		22,500