Note 10 - Related Party Transactions

6 Months Ended

Jun. 30, 2018

Notes to Financial Statements

Related Party Transactions Disclosure [Text Block]

( 1 0 ) Related Party Transactions

In

August 2016,

we granted an option to purchase

418,977

shares of common stock, with a

four

year vesting period and an exercise price of

$1.80

per share, to OPKO Health, Inc. (“OPKO”) as consideration for consulting services to be provided by OPKO. We recorded

$62,000

and

$306,000

as share-based compensation expense related to the OPKO stock option during the

six

months ended

June 30, 2018

and

2017,

respectively. The estimated grant-date fair value of the option was

$5.3

million. The term of the consulting agreement is

four

years and will be automatically renewed for successive

one

year periods. The chairman and chief executive officer of OPKO is a beneficial owner of more than

5%

of the outstanding shares of our common stock and OPKO itself is also a beneficial owner of more than

5%

of the outstanding shares of our common stock.