Nature of the business (Details) - USD ($)	1 Months Ended			3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 31, 2023	Jun. 30, 2023	Jan. 31, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Jan. 04, 2023	Oct. 01, 2021
Net loss				$ 4,345,000	$ 8,533,000	$ 14,172,000	$ 29,110,000
Accumulated deficit				130,173,000		130,173,000		$ 116,001,000
Proceeds from sales of equity and debt						155,100,000
Reimbursement expenses received								17,600,000
Deposit liability				61,000,000		61,000,000
Cash and cash equivalents				$ 90,641,000	$ 27,078,000	90,641,000	$ 27,078,000	$ 20,323,000
Prepayments from PIPE transaction recorded as deposit liability						61,000,000
Proceeds from issuance of common stock						$ 34,000
Collaboration agreement with AbbVie
Upfront payment			$ 30,000,000.0
Collaboration agreement with AbbVie | Maximum
Potentially eligible amount receivable									$ 2,800,000,000
Subscription Agreements
Sale of common stock		21,690,871
Proceeds from issuance of common stock	$ 64,000,000.0	$ 125,000,000.0
Open Market Sale
Sale of common stock			5,925			5,925
Proceeds from issuance of common stock			$ 34,000			$ 34,000
Open Market Sale | Maximum
Securities aggregate price										$ 75,000,000.0