Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 17,200	$ 20,486
Marketable securities	17,878	23,181
Accounts receivable	432	438
Prepaid expenses and other current assets	1,151	716
Total current assets	36,661	44,821
Prepaid expenses, long term		230
Property, plant and equipment, net	1,101	1,070
Total assets	37,762	46,121
Current liabilities:
Accounts payable and accrued expenses (note 7)	2,388	3,383
Loan payable, current portion (note 8)	1,400	700
Total current liabilities	3,788	4,083
Loan payable, long-term (note 8)	5,476	6,104
Total liabilities	9,264	10,187
Shareholders’ equity:
Preferred shares, without par value; unlimited shares authorized; issued and outstanding: 2,868,000 (December 31, 2017 - nil) (note 9a)	21,825
Common shares, without par value; unlimited shares authorized; issued and outstanding: 14,171,301 (December 31, 2017 - 17,998,420) (notes 9a and b)	147,887	173,841
Additional paid-in capital	36,919	36,471
Accumulated deficit	(177,143)	(173,388)
Accumulated other comprehensive loss	(990)	(990)
Shareholders' equity	28,498	35,934
Total liabilities and shareholders’ equity	37,762	46,121
Commitments and contingencies (note 10)

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

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- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.