Condensed Consolidated Statements of Stockholders' Equity (Deficit) - USD ($)	Total	Promissory Note	PIPE Investors	Former Stockholders/Executives of Aerpio Upon Merger	Common Stock	Common Stock Promissory Note	Common Stock PIPE Investors	Common Stock Former Stockholders/Executives of Aerpio Upon Merger	Additional Paid-In Capital	Additional Paid-In Capital Promissory Note	Additional Paid-In Capital PIPE Investors	Additional Paid-In Capital Former Stockholders/Executives of Aerpio Upon Merger	Accumulated Other Comprehensive Loss	Accumulated Deficit	Series Seed Preferred Stock Preferred Stock	Series A Preferred Stock Preferred Stock
Balance (in shares) at Dec. 31, 2020					2,542,000										734,000	7,212,000
Balance at Dec. 31, 2020	$ (12,432,000)				$ 1,000				$ 20,161,000					$ (32,595,000)		$ 1,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	36,000								36,000
Net loss	(5,476,000)													(5,476,000)
Balance (in shares) at Mar. 31, 2021					2,542,000										734,000	7,212,000
Balance at Mar. 31, 2021	(17,872,000)				$ 1,000				20,197,000					(38,071,000)		$ 1,000
Balance (in shares) at Dec. 31, 2020					2,542,000										734,000	7,212,000
Balance at Dec. 31, 2020	(12,432,000)				$ 1,000				20,161,000					(32,595,000)		$ 1,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(94,100,000)
Balance (in shares) at Sep. 30, 2021					20,883,000
Balance at Sep. 30, 2021	150,925,000				$ 2,000				277,618,000					(126,695,000)
Balance (in shares) at Mar. 31, 2021					2,542,000										734,000	7,212,000
Balance at Mar. 31, 2021	(17,872,000)				$ 1,000				20,197,000					(38,071,000)		$ 1,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	39,000								39,000
Net loss	(1,536,000)													(1,536,000)
Balance (in shares) at Jun. 30, 2021					2,542,000										734,000	7,212,000
Balance at Jun. 30, 2021	(19,369,000)				$ 1,000				20,236,000					(39,607,000)		$ 1,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	648,000								648,000
Issuance of common stock upon exercise of stock options (in shares)					61,000
Issuance of common stock upon exercise of stock options	745,000								745,000
Issuance of common stock (in shares)							11,853,000	3,209,000
Issuance of common stock			$ 145,384,000	$ 105,888,000			$ 1,000				$ 145,383,000	$ 105,888,000
Conversion of convertible promissory note/preferred stock in to common stock upon merger (in shares)					2,520,000	698,000									(734,000)	(7,212,000)
Conversion of convertible promissory note/preferred stock in to common stock upon merger	(1,000)	$ 9,130,000								$ 9,130,000						$ (1,000)
Cumulative dividends paid on Series A preferred stock	(4,412,000)								(4,412,000)
Net loss	(87,088,000)													(87,088,000)
Balance (in shares) at Sep. 30, 2021					20,883,000
Balance at Sep. 30, 2021	150,925,000				$ 2,000				277,618,000					(126,695,000)
Balance (in shares) at Dec. 31, 2021					20,895,000
Balance at Dec. 31, 2021	136,406,000				$ 2,000				279,089,000				$ 0	(142,685,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	1,781,000								1,781,000
Issuance of common stock upon exercise of warrants (in shares)					7,000
Issuance of common stock upon exercise of warrants	54,000								54,000
Issuance of common stock upon exercise of stock options (in shares)					40,000
Issuance of common stock upon exercise of stock options	244,000								244,000
Net loss	(13,857,000)													(13,857,000)
Balance (in shares) at Mar. 31, 2022					20,942,000
Balance at Mar. 31, 2022	124,628,000				$ 2,000				281,168,000				0	(156,542,000)
Balance (in shares) at Dec. 31, 2021					20,895,000
Balance at Dec. 31, 2021	$ 136,406,000				$ 2,000				279,089,000				0	(142,685,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)	119,396
Net loss	$ (46,600,000)
Balance (in shares) at Sep. 30, 2022					24,395,000
Balance at Sep. 30, 2022	169,108,000				$ 2,000				358,490,000				(99,000)	(189,285,000)
Balance (in shares) at Mar. 31, 2022					20,942,000
Balance at Mar. 31, 2022	124,628,000				$ 2,000				281,168,000				0	(156,542,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	2,235,000								2,235,000
Issuance of common stock upon exercise of stock options (in shares)					75,000
Issuance of common stock upon exercise of stock options	136,000								136,000
Net loss	(18,269,000)													(18,269,000)
Balance (in shares) at Jun. 30, 2022					21,017,000
Balance at Jun. 30, 2022	108,730,000				$ 2,000				283,539,000				0	(174,811,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	2,757,000								2,757,000
Issuance of common stock upon exercise of stock options (in shares)					5,000
Issuance of common stock upon exercise of stock options	16,000								16,000
Issuance of common stock (in shares)					3,373,000
Issuance of common stock	72,178,000								72,178,000
Other comprehensive loss	(99,000)												(99,000)
Net loss	(14,474,000)													(14,474,000)
Balance (in shares) at Sep. 30, 2022					24,395,000
Balance at Sep. 30, 2022	$ 169,108,000				$ 2,000				$ 358,490,000				$ (99,000)	$ (189,285,000)