Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2018

Schedule of Allocation of Stock-based Compensation

The stock-based compensation expense attributable to option grants was allocated as follows:

	Three months ended June 30,				Six months ended June 30,
	2018		2017		2018		2017
Cost of product sales	$	47	$	24	$	97	$	24
Research and development cost		77		73		189		160
General and administrative expense		224		209		206		283
Total	$	348	$	306	$	492	$	467

Schedule of Assumptions Used in Black-Scholes-Merton Option-Pricing Model

The following assumptions were used in the Black-Scholes-Merton pricing model to estimate the fair value of options granted during the periods presented.

	Three months ended June 30,						Six months ended June 30,
	2018			2017			2018			2017

Expected stock volatility		79.5%-86.3	%		71.0%-72.7	%		78.4%-86.3	%		70.9%-72.7	%
Risk free interest rate		2.4%-2.8	%		1.4%-1.7	%		2.1%-2.8	%		1.4%-1.8	%
Expected years until exercise		2.5 - 3.5			2.5 - 3.5			2.5 - 3.5			2.5 - 3.5
Dividend yield		0	%		0	%		0	%		0	%