Note F - Common Stock and Warrants (Tables)

3 Months Ended

Mar. 31, 2019

Notes Tables

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

	March 31, 2019		December 31, 2018
Conversion of Deerfield Convertible Note		1,166,998		1,167,607
Conversion of 2021 Notes		4,481,182		4,481,182
Outstanding awards under equity incentive plans		5,117,655		3,704,755
Outstanding common stock warrants		2,527,763		2,527,763
Conversion of Series A Convertible Preferred Stock		1,112,334		1,112,334
Possible future issuances under equity incentive plans		293,586		648,272
Total common shares reserved for future issuance		14,699,518		13,641,913

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

	Shares of Common Stock
Balance as of December 31, 2018		26,455,352
Common stock issued under Purchase Agreement		1,521,471
Balance as of March 31, 2019		27,976,823