Research and Development Agreements (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	May 04, 2019	Apr. 29, 2019	Jun. 27, 2012
UNC License Agreement
Collaborative Arrangements Transactions [Line Items]
Potential regulatory and commercial milestones payable under agreement							$ 425,000
Ligand Pharmaceuticals Incorporated
Collaborative Arrangements Transactions [Line Items]
Immediate funding					$ 12,000,000
Potential regulatory and commercial milestones payable under agreement					$ 20,000,000
Minimum | Ligand Pharmaceuticals Incorporated
Collaborative Arrangements Transactions [Line Items]
Tiered royalties, percentage					7.00%
Maximum | Ligand Pharmaceuticals Incorporated
Collaborative Arrangements Transactions [Line Items]
Tiered royalties, percentage					10.00%
SB206 | Ligand Pharmaceuticals Incorporated
Collaborative Arrangements Transactions [Line Items]
Research and development expense (contra expense)	$ (223,000)	$ (117,000)	$ (851,000)	$ 93,000
Restricted Cash | SB206 | Ligand Pharmaceuticals Incorporated
Collaborative Arrangements Transactions [Line Items]
Immediate funding					$ 12,000,000
Reedy Creek Investments LLC
Collaborative Arrangements Transactions [Line Items]
Immediate funding						$ 25,000,000
Reedy Creek Investments LLC | Cash and Cash Equivalents
Collaborative Arrangements Transactions [Line Items]
Immediate funding						$ 25,000,000