Condensed Consolidated Balance Sheets - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 2,346,978	$ 5,838,566
Investment in debt securities - available for sale, at fair value	7,461,875	9,857,087
Advances and deposits on clinical programs and other current assets	2,285,490	2,545,051
Total current assets	12,094,343	18,240,704
Property and equipment (at cost, less accumulated depreciation and amortization)	693,360	751,906
Other assets:
Deferred income tax asset		1,280,385
Operating lease right-of-use assets, net	1,487,065	1,595,074
Deposits and other assets	50,000	50,000
Total other assets	1,537,065	2,925,459
Total assets	14,324,768	21,918,069
Current liabilities:
Accounts payable – trade	2,357,776	3,515,192
Other accrued liabilities	1,958,575	3,390,521
Operating lease liability - current portion	500,625	485,421
Total current liabilities	4,816,976	7,391,134
Operating lease liability - non-current portion	1,008,049	1,139,293
Total liabilities	5,825,025	8,530,427
Commitments and contingencies
Stockholders’ equity:
Preferred stock - $0.01 par value (100,000 shares authorized, and no shares issued or outstanding at March 31, 2024 and December 31, 2023)
Common stock - $0.01 par value (112,500,000 shares authorized; 9,400,911 and 9,399,811 shares issued at March 31, 2024 and December 31, 2023, respectively; and 9,400,889 and 9,399,789 shares outstanding at March 31, 2024 and December 31, 2023, respectively)	94,009	93,998
Additional paid-in capital	401,470,148	401,500,838
Accumulated other comprehensive loss	133,101	60,796
Accumulated deficit	(393,112,327)	(388,182,802)
Total stockholders’ equity before treasury stock	8,584,931	13,472,830
Treasury stock, at cost (22 shares at March 31, 2024 and December 31, 2023)	(85,188)	(85,188)
Total stockholders’ equity	8,499,743	13,387,642
Total liabilities and stockholders’ equity	$ 14,324,768	$ 21,918,069

Carrying value as of the balance sheet date of obligations incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).