Note 6 - Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2019

Notes Tables

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (years)		Aggregate Intrinsic Value
Outstanding at December 31, 2018		4,597,226		$	5.12		7.4	$	404
Granted		1,182,500		$	2.66
Exercised		-
Forfeited (1)		(2,606,289	)	$	2.79
Expired (1)		(2,400,590	)	$	6.51
Outstanding at September 30, 2019		772,847		$	4.89		7.3	$	-
Exercisable at September 30, 2019		476,390		$	6.13		6.4	$	-
Vested or expected to vest at September 30, 2019 (2)		772,847		$	4.89		7.3	$	-

Common Stock Reserved for Future Issuance [Table Text Block]

<div style="display: inline; font-family: times new roman; font-size: 10pt"><table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font: 10pt Times New Roman, Times, Serif; min-; min-width: 700px;"> <tr style="vertical-align: bottom"> <td style="white-space: nowrap"> </td> <td style="font-weight: bold; padding-bottom: 1pt"> </td> <td colspan="3" style="white-space: nowrap; font-weight: bold; text-align: center; border-bottom: Black 1pt solid">September 30,</td> <td style="font-weight: bold; padding-bottom: 1pt"> </td> <td colspan="3" style="white-space: nowrap; font-weight: bold; text-align: center; border-bottom: Black 1pt solid">December 31,</td> </tr> <tr style="vertical-align: bottom"> <td style="white-space: nowrap"> </td> <td style="font-weight: bold; padding-bottom: 1pt"> </td> <td colspan="3" style="white-space: nowrap; font-weight: bold; text-align: center; border-bottom: Black 1pt solid">2019</td> <td style="font-weight: bold; padding-bottom: 1pt"> </td> <td colspan="3" style="white-space: nowrap; font-weight: bold; text-align: center; border-bottom: Black 1pt solid">2018</td> </tr> <tr style="vertical-align: bottom"> <td style="white-space: nowrap"> </td> <td> </td> <td colspan="3" style="white-space: nowrap; text-align: center"> </td> <td> </td> <td colspan="3" style="white-space: nowrap; text-align: center"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204,238,255)"> <td style="width: 70%; text-align: left">Conversion of Series A Preferred Stock</td> <td style="width: 1%"> </td> <td style="width: 1%; text-align: left"> </td> <td style="width: 12%; text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">21,771,032</div></td> <td style="white-space: nowrap; width: 1%; text-align: left"> </td> <td style="width: 1%"> </td> <td style="width: 1%; text-align: left"> </td> <td style="width: 12%; text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">22,112,775</div></td> <td style="white-space: nowrap; width: 1%; text-align: left"> </td> </tr> <tr style="vertical-align: bottom; background-color: White"> <td style="text-align: left">Stock-based compensation awards</td> <td> </td> <td style="text-align: left"> </td> <td style="text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">6,818,214</div></td> <td style="white-space: nowrap; text-align: left"> </td> <td> </td> <td style="text-align: left"> </td> <td style="text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">5,163,957</div></td> <td style="white-space: nowrap; text-align: left"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204,238,255)"> <td style="text-align: left; padding-bottom: 1pt">Employee Stock Purchase Plan</td> <td style="padding-bottom: 1pt"> </td> <td style="border-bottom: Black 1pt solid; text-align: left"> </td> <td style="border-bottom: Black 1pt solid; text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">118,120</div></td> <td style="white-space: nowrap; border-bottom: Black 1pt solid; text-align: left"> </td> <td style="padding-bottom: 1pt"> </td> <td style="border-bottom: Black 1pt solid; text-align: left"> </td> <td style="border-bottom: Black 1pt solid; text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">118,120</div></td> <td style="white-space: nowrap; border-bottom: Black 1pt solid; text-align: left"> </td> </tr> <tr style="vertical-align: bottom; background-color: White"> <td style="padding-bottom: 2.25pt">Total</td> <td style="padding-bottom: 2.25pt"> </td> <td style="border-bottom: Black 2.25pt double; text-align: left"> </td> <td style="border-bottom: Black 2.25pt double; text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">28,707,366</div></td> <td style="white-space: nowrap; border-bottom: Black 2.25pt double; text-align: left"> </td> <td style="padding-bottom: 2.25pt"> </td> <td style="border-bottom: Black 2.25pt double; text-align: left"> </td> <td style="border-bottom: Black 2.25pt double; text-align: right"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">27,394,852</div></td> <td style="white-space: nowrap; border-bottom: Black 2.25pt double; text-align: left"> </td> </tr> </table></div>