Quarterly report pursuant to Section 13 or 15(d)

LICENSE AGREEMENT - ADDITIONAL INFORMATION - (Detail)

v3.19.3
LICENSE AGREEMENT - ADDITIONAL INFORMATION - (Detail) - USD ($)
shares in Millions, $ in Millions
 3 Months Ended
Aug. 04, 2017
Sep. 30, 2019
Research and Development Arrangement, Contract to Perform for Others [Line Items]    
Qualified Financing Future Cash Payments, Early Payments Obligation   $ 3.4
License agreement    
Research and Development Arrangement, Contract to Perform for Others [Line Items]    
Proceeds from Issuance of Private Placement, Net of Advisory Fees Payable   22.6
Qualified Financing Future Cash Payments, Early Payments Obligation   3.4
ActiveSite Pharmaceuticals, Inc. [Member]    
Research and Development Arrangement, Contract to Perform for Others [Line Items]    
Maximum Amount of Milestone Events   36.0
First milestone payment due after completion of the preclinical work   $ 1.0
Royalties percentage   2.00%
Minimum | ActiveSite Pharmaceuticals, Inc. [Member]    
Research and Development Arrangement, Contract to Perform for Others [Line Items]    
Milestone Payments $ 1.0  
Maximum [Member] | ActiveSite Pharmaceuticals, Inc. [Member]    
Research and Development Arrangement, Contract to Perform for Others [Line Items]    
Milestone Payments $ 10.0  
Total royalty payments   $ 10.0
Xoma | License agreement    
Research and Development Arrangement, Contract to Perform for Others [Line Items]    
Stock Issued During Period, Shares, Other   8.1
Put Option [Member] | Xoma | License agreement    
Research and Development Arrangement, Contract to Perform for Others [Line Items]    
Description Of Option Indexed To Issuers Equity Shares   Xoma may exercise the Put option for up to a total of 2.5 million shares of Common Stock for the fiscal year ending December 31, 2020, and up to an additional 2.5 million shares thereafter.