COMMITMENTS AND CONTINGENCIES - Narrative (Details) € in Thousands			1 Months Ended	3 Months Ended
	Dec. 31, 2019 EUR (€)	Dec. 31, 2019 USD ($)	Oct. 31, 2010 USD ($)	Mar. 31, 2020 USD ($) arrangement renewal_term	Mar. 31, 2019 USD ($)	Jan. 01, 2020 USD ($)
Commitments and Contingencies [Line Items]
Term of employee's base salary				3 months
Term of employee health coverage				3 months
Number of renewal terms (up to) | renewal_term				2
Renewal term				3 years
Operating lease liability				$ 306,000		$ 400,000
Lease discount rate				6.00%
Lease remaining term				12 months
Rent expense				$ 100,000	$ 100,000
Remaining lease term				9 months
Operating lease right-of-use asset, net				$ 266,000		$ 400,000
Future annual minimum payment 2020				300,000
Future lease payments due				700,000
Operating expenses of leases				$ 100,000	$ 100,000
Yale University
Commitments and Contingencies [Line Items]
Term of agreement				5 years
Proceeds from collaboration				$ 1,000,000
University of Texas
Commitments and Contingencies [Line Items]
Number of arrangements | arrangement				1
Nonrefundable upfront license documentation fee				$ 10,000
Annual license maintenance fee				10,000
Potential milestone payment for initiation of defined clinical trials (up to)				600,000
License fee expense				0
University of Texas | United States
Commitments and Contingencies [Line Items]
Potential milestone payment for regulatory approval (up to)				2,000,000
University of Texas | Other Regions
Commitments and Contingencies [Line Items]
Potential milestone payment for regulatory approval (up to)				500,000
RICC
Commitments and Contingencies [Line Items]
Potential future milestone payments per licensed product (up to)				5,200,000.0
Payments for raw materials				0
t2cure
Commitments and Contingencies [Line Items]
Nonrefundable upfront license documentation fee			$ 46,000
Annual license maintenance fee	€ 3	$ 3,000
Potential milestone payment for initiation of defined clinical trials (up to)				$ 700,000
Term of agreement				10 years
Period to terminate agreement				60 days
t2cure | United States
Commitments and Contingencies [Line Items]
Potential milestone payment for regulatory approval (up to)				$ 2,500,000
t2cure | European Union or Japan
Commitments and Contingencies [Line Items]
Potential milestone payment for regulatory approval (up to)				$ 1,500,000.0
Minimum
Commitments and Contingencies [Line Items]
Resignation for good reason term				1 month
Change on control term				1 month
Maximum
Commitments and Contingencies [Line Items]
Term of employee's base salary				12 months
Term of executive’s outstanding unvested stock options				3 months
Term of employee health coverage				12 months
Resignation for good reason term				12 months
Change on control term				12 months
Chief Executive Officer
Commitments and Contingencies [Line Items]
Term of employee health coverage				12 months
Total compensation due to change in control, in base salary term				24 months