INVENTORY

Inventory consisted of the following (in thousands):



	March 31, 2018		December 31, 2017
Raw materials	$	1,937	$	498
Work in process	3,726		3,997
Finished goods	2,977		2,854
Total	$	8,640	$	7,349

Balance Sheet classification:
Inventory	$	7,563	$	6,657
Other long-term assets	1,077		692
Total	$	8,640	$	7,349

A portion of the manufacturing costs for inventory was incurred prior to regulatory approval of CABOMETYX and COMETRIQ and therefore was expensed as research and development costs when those costs were incurred, rather than capitalized as inventory. As of both March 31, 2018 and December 31, 2017 our inventory includes $0.4 million of materials that were previously expensed.

Write-downs related to excess and expiring inventory are charged to either Cost of goods sold or the cost of supplied product included in Collaboration revenues. Such write-downs were $0.5 million for the three months ended March 31, 2017. There were no such write-downs for the three months ended March 31, 2018.

Inventory expected to be used or sold in periods more than 12 months from the date presented is classified as Other long-term assets on the accompanying Condensed Consolidated Balance Sheets. As of both March 31, 2018 and December 31, 2017, the non-current portion of inventory consisted of finished goods.