Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2019

Schedule of the allocation of stock-based compensation

The stock-based compensation expense was allocated as follows:



	Three months ended June 30,				Six months ended June 30,
	2019		2018		2019		2018
Cost of product sales	$	17	$	47	$	92	$	97
Research and development cost	19		77		134		189
General and administrative expense	894		224		1,772		206
Total	$	930	$	348	$	1,998	$	492

Schedule of assumptions used in the 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,
	2019		2018		2019		2018

Expected stock volatility	86.3% - 87.5%		79.5% - 86.3%		82.3% - 87.5%		78.4% - 86.3%
Risk free interest rate	2.2% - 2.3%		2.4% - 2.8%		2.2% - 2.5%		2.1% - 2.8%
Expected years until exercise	2.8 - 3.4		2.5 - 3.5		2.2 - 2.5		2.5 - 3.5
Dividend yield	0	%	0	%	0	%	0	%