Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Promissory Note [Member]	PIPE Investors [Member]	Former Stockholders/Executives of Aerpio Upon Merger [Member]	Preferred Stock [Member] Series Seed Preferred Stock [Member]	Preferred Stock [Member] Series A Preferred Stock [Member]	Common Stock	Common Stock Promissory Note [Member]	Common Stock PIPE Investors [Member]	Common Stock Former Stockholders/Executives of Aerpio Upon Merger [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Promissory Note [Member]	Additional Paid-in Capital [Member] PIPE Investors [Member]	Additional Paid-in Capital [Member] Former Stockholders/Executives of Aerpio Upon Merger [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2019	$ (9,093)					$ 1	$ 1				$ 20,022				$ (29,117)
Balance, Shares at Dec. 31, 2019					734,000	7,212,000	2,542,000
Share-based compensation expense	139										139
Net and comprehensive loss	(3,478)														(3,478)
Balance at Dec. 31, 2020	(12,432)					$ 1	$ 1				20,161				(32,595)
Balance, Shares at Dec. 31, 2020					734,000	7,212,000	2,542,000
Exercise of stock options to purchase common stock	$ 833										833
Exercise of stock options to purchase common stock, shares	72,316						73,000
Issuance of common stock			$ 145,384	$ 105,888					$ 1				$ 145,383	$ 105,888
Issuance of common stock, Shares									11,853,000	3,209,000
Conversion of convertible promissory note/preferred stock in to common stock upon merger	$ (1)	$ 9,130				$ (1)						$ 9,130
Conversion of convertible promissory note/preferred stock in to common stock upon merger, shares					(734,000)	(7,212,000)	2,520,000	698,000
Share-based compensation expense	2,106										2,106
Cumulative dividends paid on Series A preferred stock	(4,412)										(4,412)
Net and comprehensive loss	(110,090)														(110,090)
Balance at Dec. 31, 2021	$ 136,406						$ 2				$ 279,089				$ (142,685)
Balance, Shares at Dec. 31, 2021							20,895,000