Note F - Common Stock and Warrants (Tables)

6 Months Ended

Jun. 30, 2020

Notes Tables

Schedule of Authorized Shares of Common Stock Reserved for Future Issuance [Table Text Block]

	June 30, 2020		December 31, 2019
Conversion of Deerfield Convertible Note		1,254,682		1,213,606
Conversion of 2021 Notes		—		175,336
Conversion of January 2020 Note		535,513		—
Conversion of December 2019 Notes not subject to the Deerfield Optional Conversion Feature		9,677,740		3,186,770
Outstanding awards under equity incentive plans		5,697,534		5,192,222
Outstanding common stock warrants		2,423,077		2,423,077
In exchange for the Deerfield Optional Conversion Feature*		5,189,015		26,439,015
Possible future issuances under the equity line of credit		—		9,553,046
Possible future issuances under equity incentive plans		803,473		84,616
Total common shares reserved for future issuance		25,581,034		48,267,688
* Common Stock issuable (i) in exchange of the Deerfield Optional Conversion Feature, or (ii) upon conversion of the Series B-2 Preferred Stock issuable in exchange of the Deerfield Optional Conversion Feature

Schedule of Common Stock Outstanding Roll Forward [Table Text Block]

	Shares of Common Stock
Balance as of December 31, 2019		36,350,785
Common stock issued under equity line of credit		4,308,637
Restricted stock vested during the period		60,922
Common stock issued as compensation to third-parties		39,767
Common stock issued as a result of Deerfield Optional Conversion Feature conversion		16,000,000
Balance as of March 31, 2020		56,760,111
Common stock issued under equity line of credit		4,959,545
Restricted stock vested during the period		64,277
Common stock issued as compensation to third-parties		189,980
Common stock issued as a result of Deerfield Optional Conversion Feature conversion		5,250,000
Balance as of June 30, 2020		67,223,913