Stock Options, Unrecognized Expense (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Unrecognized Stock-based Compensation Expense [Abstract]
Unrecognized stock-based compensation expense	$ 1,100,000	$ 2,000,000.0
Vesting Over Remaining Term [Member]
Unrecognized Stock-based Compensation Expense [Abstract]
Unrecognized stock-based compensation expense	$ 900,000	$ 1,000,000.0
Average remaining vesting term of the stock options (in years)	1 year 10 months 6 days	8 years 5 months 1 day
Initiating Phase 3 Trial in US [Member]
Unrecognized Stock-based Compensation Expense [Abstract]
Unrecognized stock-based compensation expense	$ 40,000	$ 40,000
Public Release of Topline Data of Complete Combination Trial Results [Member]
Unrecognized Stock-based Compensation Expense [Abstract]
Unrecognized stock-based compensation expense	140,000	168,000
Signing of Definitive Term Sheet with Board Approval [Member]
Unrecognized Stock-based Compensation Expense [Abstract]
Unrecognized stock-based compensation expense	$ 140,000
Completing Enrollment of Phase 2 OPTION 2 Clinical Trial [Member]
Unrecognized Stock-based Compensation Expense [Abstract]
Unrecognized stock-based compensation expense		440,000
Completing Enrollment in Phase 2 Combination Trial in Europe [Member]
Unrecognized Stock-based Compensation Expense [Abstract]
Unrecognized stock-based compensation expense		41,000
Public Release of Topline Data [Member]
Unrecognized Stock-based Compensation Expense [Abstract]
Unrecognized stock-based compensation expense		140,000
Initiating Phase 1 Trial for Product Other than MS1819 [Member]
Unrecognized Stock-based Compensation Expense [Abstract]
Unrecognized stock-based compensation expense		40,000
Signing Definitive Term Sheet [Member]
Unrecognized Stock-based Compensation Expense [Abstract]
Unrecognized stock-based compensation expense		$ 140,000