License, Collaborative and Employment Agreements and Commitments - Additional Information (Details) - USD ($)											1 Months Ended				12 Months Ended
	Dec. 30, 2020	Aug. 07, 2019	Sep. 05, 2018	Sep. 05, 2018	Aug. 31, 2015	Aug. 29, 2015	Aug. 10, 2015	Dec. 05, 2013	Dec. 05, 2013	Oct. 05, 2012	Nov. 30, 2017	Dec. 19, 2012	Dec. 19, 2012	Nov. 28, 2012	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2015
License, Collaborative and Employment Agreements and Commitments [Line Items]
Payments for Other Fees											$ 4,500,000
Exchange percentage of unregistered common stock								50.00%	50.00%
Proceeds from (Repurchase of) Equity									$ 3,000,000
Options To Be Received Common Stock Shares															2,000,000
Milestone Payment upon First Dosing				$ 3,000,000											$ 3,000,000
Fair Value Of Shares Issued			$ 285,000
Operating Lease, Cost															209,000	$ 201,000
Operating Lease, Payments															$ 309,000	300,000
Operating Lease, Weighted Average Discount Rate, Percent															9.90%
Research and Development Expense			$ 198,000												$ 5,131,000	11,083,000
SYN Biomics [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Additional Number Of Common Stock To Be Issued			2,420,000	2,420,000
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners															17.00%
Cedarssinai Medical Center [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Percentage Of Common Stock Outstanding									11.50%
Payments to Acquire in Process Research and Development			$ 441,000
Number Of Common Stock To Be Issued			50,000	50,000
Number Of Common Stock To Be Held By Related Party			7,480,000	7,480,000
Cedarssinai Medical Center [Member] | SYN Biomics [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Additional Number Of Common Stock To Be Issued			2,420,000	2,420,000
Mark Pimentel M.D [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Percentage Of Common Stock Outstanding									8.50%
Licensing Agreements [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Annual payments due under license agreement												$ 50,000
Final payment due under license agreement												25,000
Payments for Other Fees								$ 150,000
Stock Issued During Period, Shares, New Issues								9,569
Patents [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Payments for Other Fees								$ 220,000
Steven A. Shallcross [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Deferred Compensation Arrangement with Individual, Cash Awards Granted, Percentage	62.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	450,000
Intrexon [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Stock Issued During Period, Shares, Acquisitions										101,492
Shares Issued, Price Per Share										$ 0.001
Milestone Payment upon First Dosing							$ 2,000,000								$ 2,000,000
Prev Abr Llc [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Additional Cash Payment for License Agreement														$ 235,000
Unregistered Shares Issued to License Agreement														17,858
Additional Consideration Payable														50% in cash and 50% in our stock
Options To Be Received Common Stock Shares																	18,724
Phase I Clinical Trials [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Milestone Payment													$ 50,000
Phase III Clinical Trials [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Milestone Payment													100,000
NDA Submission In US [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Milestone Payment													250,000
European Medicines Agency Approval [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Milestone Payment													100,000
Regulatory Approval In Asian Country [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Milestone Payment													100,000
PKU ECC [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Shares, Issued							26,786
Stock Issued							$ 3,000,000
Stock Purchase Agreement [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Conversion of Stock, Shares Converted						38,572
Conversion of Stock, Shares Issued					38,572
Research and Development Expense				$ 225,000											$ 225,000	$ 198,000
Clinical Trial Agreement [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Estimated Research Costs		$ 3,200,000
First Year [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Research Agreement Fixed Fee												303,287	303,287
Second Year [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Research Agreement Fixed Fee												316,438	316,438
Third Year [Member]
License, Collaborative and Employment Agreements and Commitments [Line Items]
Research Agreement Fixed Fee												$ 328,758	$ 328,758