Nature of Business (Details)			12 Months Ended
	Feb. 06, 2016 USD ($)	Feb. 05, 2016 USD ($)	Dec. 31, 2015 USD ($) Program Patient ClinicalSite	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)
Nature of Business [Abstract]
Number of programs in clinical development for cancer indications | Program			2
Number of patients enrolled | Patient			400
Number of clinical sites | ClinicalSite			79
Estimated Projected Expenditure Type [Line Items]
Cash and cash equivalents			$ 22,261,372	$ 32,218,905	$ 11,483,112	$ 14,344,088
Short-term investments			35,035,420	$ 45,621,593
Projected expenditures for clinical programs			58,900,000
Subsequent Event [Member] | Hercules Technology Growth Capital, Inc. and Hercules Technology III, L.P. [Member]
Estimated Projected Expenditure Type [Line Items]
Maximum borrowing capacity under long-term loan agreement	$ 40,000,000	$ 40,000,000
Amount received under long-term loan agreement	$ 25,000,000	$ 25,000,000
Aldoxorubicin [Member]
Estimated Projected Expenditure Type [Line Items]
Projected expenditures for clinical programs			34,300,000
Albumin-Binding Cancer Drugs [Member]
Estimated Projected Expenditure Type [Line Items]
Projected expenditures for clinical programs			5,400,000
General Operation [Member]
Estimated Projected Expenditure Type [Line Items]
Projected expenditures for clinical programs			4,200,000
Other General and Administrative Expenses [Member]
Estimated Projected Expenditure Type [Line Items]
Projected expenditures for clinical programs			$ 15,000,000