Restatement of Previously Issued Consolidated Financial Statements - Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 39,462	$ 53,477	$ 70,578	$ 68,259	$ 77,563	$ 101,602	$ 115,005	$ 129,771
Marketable securities	0	0	0	8,462	13,371	0	0	0
Prepaid expenses and other current assets	3,509	3,081	2,874	7,680	7,558	5,895	7,564	8,256
Total current assets	42,971	56,558	73,452	84,401	98,492	107,497	122,569	138,027
Property and equipment, net	17,290	14,469	11,720	7,952	6,053	4,517	3,153	1,921
Restricted cash				0				151
Other assets	4,286	3,660	3,804	3,946	4,087	4,225	4,366	1,628
Total assets	64,547	74,687	88,976	96,299	108,632	116,239	130,088	141,727
Current liabilities
Accounts payable	3,172	2,921	3,881	8,092	8,062	6,460	5,921	3,896
Accrued expenses and other current liabilities	13,343	14,993	18,826	16,722	19,971	17,620	11,728	9,151
Operating lease obligations	574	540	526	512	498	443	314	254
Current portion of long term debt		1,276	1,266	1,256		0	0	0
Total current liabilities	17,089	19,730	24,499	26,582	28,531	24,523	17,963	13,301
Non-current liabilities
Operating lease obligations, less current portion	3,567	3,164	3,308	3,449	3,587	3,764	3,892	1,180
Long term debt, net	2,800	1,495	1,472	1,058	2,289	2,265	1,750	1,731
Other non-current liabilities	527	497	455	309	244	0	0	0
Total non-current liabilities	6,894	5,156	5,235	4,816	6,120	6,029	5,642	2,911
Total liabilities	23,983	24,886	29,734	31,398	34,651	30,552	23,605	16,212
Commitments and contingencies
Stockholders' equity
Common stock	2,567	2,566	2,566	2,265	2,217	2,168	2,163	2,158
Treasury stock	(48)	(48)	(48)	(48)	(48)	(48)	(48)	(48)
Additional paid-in capital	324,191	322,452	320,181	303,073	294,874	284,231	281,139	278,704
Accumulated other comprehensive income	20	27	22	25	26	30	10	0
Accumulated deficit	(286,167)	(275,197)	(263,480)	(240,415)	(223,089)	(200,695)	(176,782)	(155,300)
Total stockholders' equity	40,564	49,801	59,242	64,901	73,981	85,687	106,483	125,515	$ 91,200
Total liabilities and stockholders' equity	64,547	74,687	88,976	96,299	108,632	116,239	130,088	141,727
Series A Convertible Preferred Stock
Stockholders' equity
Convertible preferred stock	0	0	0	0	0	0	0	0
Series B Convertible Preferred Stock
Stockholders' equity
Convertible preferred stock	$ 1	1	1	1	1	1	1	1	5,000
As previously reported
Current assets
Cash and cash equivalents		53,477	70,578	68,259		101,602	115,005	129,771
Marketable securities		0	0	8,462		0	0	0
Prepaid expenses and other current assets		3,081	2,874	7,680		5,895	7,564	8,256
Total current assets		56,558	73,452	84,401		107,497	122,569	138,027
Property and equipment, net		14,469	11,720	7,952		4,517	3,153	1,921
Restricted cash				0				151
Other assets		3,660	3,804	3,946		4,225	4,366	1,628
Total assets		74,687	88,976	96,299		116,239	130,088	141,727
Current liabilities
Accounts payable		2,921	3,881	8,092		6,460	5,921	3,896
Accrued expenses and other current liabilities		6,399	7,787	5,823	9,900	8,004	4,103	3,537
Operating lease obligations		540	526	512		443	314	254
Current portion of long term debt		1,276	1,266	1,256		0	0	0
Total current liabilities		11,136	13,460	15,683	18,460	14,907	10,338	7,687
Non-current liabilities
Operating lease obligations, less current portion		3,164	3,308	3,449		3,764	3,892	1,180
Long term debt, net		1,495	1,472	1,058		2,265	1,750	1,731
Other non-current liabilities		497	455	309		0	0	0
Total non-current liabilities		5,156	5,235	4,816		6,029	5,642	2,911
Total liabilities		16,292	18,695	20,499	24,580	20,936	15,980	10,598
Commitments and contingencies
Stockholders' equity
Common stock		2,566	2,566	2,265		2,168	2,163	2,158
Treasury stock		(48)	(48)	(48)		(48)	(48)	(48)
Additional paid-in capital		322,452	320,181	303,073		284,231	281,139	278,704
Accumulated other comprehensive income		27	22	25		30	10	0
Accumulated deficit		(266,603)	(252,441)	(229,516)	(213,018)	(191,079)	(169,157)	(149,686)
Total stockholders' equity		58,395	70,281	75,800	84,052	95,303	114,108	131,129	95,818
Total liabilities and stockholders' equity		74,687	88,976	96,299		116,239	130,088	141,727
As previously reported | Series A Convertible Preferred Stock
Stockholders' equity
Convertible preferred stock		0	0	0		0	0	0
As previously reported | Series B Convertible Preferred Stock
Stockholders' equity
Convertible preferred stock		1	1	1		1	1	1
Adjustment
Current assets
Cash and cash equivalents		0	0	0		0	0	0
Marketable securities		0	0	0		0	0	0
Prepaid expenses and other current assets		0	0	0		0	0	0
Total current assets		0	0	0		0	0	0
Property and equipment, net		0	0	0		0	0	0
Restricted cash				0				0
Other assets		0	0	0		0	0	0
Total assets		0	0	0		0	0	0
Current liabilities
Accounts payable		0	0	0		0	0	0
Accrued expenses and other current liabilities		8,594	11,039	10,899	10,071	9,616	7,625	5,614
Operating lease obligations		0	0	0		0	0	0
Current portion of long term debt		0	0	0		0	0	0
Total current liabilities		8,594	11,039	10,899	10,071	9,616	7,625	5,614
Non-current liabilities
Operating lease obligations, less current portion		0	0	0		0	0	0
Long term debt, net		0	0	0		0	0	0
Other non-current liabilities		0	0	0		0	0	0
Total non-current liabilities		0	0	0		0	0	0
Total liabilities		8,594	11,039	10,899	10,071	9,616	7,625	5,614
Commitments and contingencies
Stockholders' equity
Common stock		0	0	0		0	0	0
Treasury stock		0	0	0		0	0	0
Additional paid-in capital		0	0	0		0	0	0
Accumulated other comprehensive income		0	0	0		0	0	0
Accumulated deficit		(8,594)	(11,039)	(10,899)	(10,071)	(9,616)	(7,625)	(5,614)
Total stockholders' equity		(8,594)	(11,039)	(10,899)	$ (10,071)	(9,616)	(7,625)	(5,614)	$ (4,618)
Total liabilities and stockholders' equity		0	0	0		0	0	0
Adjustment | Series A Convertible Preferred Stock
Stockholders' equity
Convertible preferred stock		0	0	0		0	0	0
Adjustment | Series B Convertible Preferred Stock
Stockholders' equity
Convertible preferred stock		$ 0	$ 0	$ 0		$ 0	$ 0	$ 0