Inventory

The major classes of inventory were as follows:



	September 30, 2018		December 31, 2017
	(in thousands)
Raw materials	$	866	$	1,389
Work-in-progress	—		3,608
Finished goods	—		562
Total	$	866	$	5,559

The Company reviews inventory, including inventory purchase commitments, for slow moving or obsolete amounts based on expected product sales volume and provides reserves against the carrying amount of inventory as appropriate. If annual volume is less than expected, the Company may be required to make additional allowances for excess or obsolete inventory in the future.