License Agreements (Details Textual) - USD ($)		1 Months Ended				3 Months Ended	12 Months Ended
	May 11, 2015	May 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Neupharma [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payment of Upfront Fees					$ 1,000,000
Reimbursement Of Cost Recognized As Revenue							$ 35,000	$ 600,000
Neupharma [Member] | Additional Sales Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum Potential Milestone Payments							40,000,000
Neupharma [Member] | Clinical and Development Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum Potential Milestone Payments							40,000,000
Neupharma [Member] | Regulatory Approvals To Commercialize The Products [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum Potential Milestone Payments							22,500,000
Dana-Farber [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Shares Issued, Price Per Share	$ 0.065
Stock Issued During Period, Shares, Issued for Services	500,000			136,830
Stock Issued During Period, Value, Issued for Services	$ 32,500			$ 600,000
Payment of Upfront Fees					1,000,000
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	5.00%
Cash In Exchange For Common Stock	$ 10,000,000
Payment For Non refundable Milestone payments						$ 1,000,000
Maintenance Fee							50,000
Dana-Farber [Member] | First Commercial Sale Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue Recognition Milestone Method, Payments Due							21,500,000
Maximum Potential Milestone Payments							21,500,000
Dana-Farber [Member] | Additional Sales Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue Recognition Milestone Method, Payments Due							60,000,000
Maximum Potential Milestone Payments							60,000,000
Teva Pharmaceutical Industries Ltd [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payment of Upfront Fees			$ 500,000
Jubilant Biosys Ltd [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payment of Upfront Fees									$ 2,000,000
Revenue Recognition, Milestone Method, Revenue Recognized							$ 400,000	1,000,000
Research and Development Cost, Shared Percentage							50.00%
Non-Refundable Milestone Payment								400,000
Proceeds from Upfront Fees		$ 1,000,000
Jubilant Biosys Ltd [Member] | Clinical and Development Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum Potential Milestone Payments							$ 89,000,000
Jubilant Biosys Ltd [Member] | Regulatory Approvals To Commercialize The Products [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum Potential Milestone Payments							59,500,000
Jubilant Biosys Ltd [Member] | Five Regulatory Approvals And First Commercial Sales [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue Recognition Milestone Method, Payments Due							61,700,000
Jubilant Biosys Ltd [Member] | Sale Millstone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue Recognition Milestone Method, Payments Due							89,000,000
Maximum Potential Milestone Payments							89,000,000
Jubilant Biosys Ltd [Member] | Clinical Development and Regulatory Milestones [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue Recognition Milestone Method, Payments Due							87,200,000
Adimab LLC [Member] | Clinical and Development Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum Potential Milestone Payments							7,100,000
Adimab LLC [Member] | Regulatory Approvals To Commercialize The Products [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum Potential Milestone Payments							4,800,000
Collaboration Agreement With TGTX [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue Recognition, Milestone Method, Revenue Recognized							3,000,000	$ 100,000
Proceeds from Upfront Fees					$ 500,000
Collaboration Agreement With TGTX [Member] | Clinical and Development Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue Recognition Milestone Method, Payments Due							7,000,000
Collaboration Agreement With TGTX [Member] | Commercial Sales In Specified Territories [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue Recognition Milestone Method, Payments Due							14,500,000
Sublicense Agreement with TGTX [Member] | Clinical and Development Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue Recognition Milestone Method, Payments Due							$ 25,500,000