International Stem Cell (ISCO) 10-K 15 Apr 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Apr. 10, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Trading Symbol	ISCO
Entity Registrant Name	International Stem Cell CORP
Entity Central Index Key	0001355790
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		7,533,083
Entity Public Float			$ 3,948,263

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash	$ 1,075	$ 304
Accounts receivable, net of allowance for doubtful accounts of $12	651	465
Inventory, net	1,501	1,307
Prepaid expenses and other current assets	543	779
Total current assets	3,770	2,855
Non-current inventory	805	692
Property and equipment, net	469	321
Intangible assets, net	2,674	2,922
Deposits and other assets	78	74
Total assets	7,796	6,864
Liabilities and Stockholders' Equity
Accounts payable	458	830
Accrued liabilities	579	607
Related party payable	2,045
Advances	250	250
Fair value of warrant liability	1,745	3,113
Total current liabilities	5,077	4,800
Long-term deferred rent	182
Total liabilities	5,259	4,800
Commitments and contingencies (Note 10)
Stockholders' Equity
Common stock, $0.001 par value, 120,000,000 shares authorized, 6,933,861 and 6,057,132 shares issued and outstanding at December 31, 2018 and 2017, respectively	7	6
Additional paid-in capital	109,188	106,585
Accumulated deficit	(106,663)	(104,532)
Total stockholders' equity	2,537	2,064
Total liabilities and stockholders' equity	7,796	6,864
Series B Preferred Stock [Member]
Stockholders' Equity
Convertible Preferred stock
Series D Preferred Stock [Member]
Stockholders' Equity
Convertible Preferred stock
Series I-1 Preferred Stock [Member]
Stockholders' Equity
Convertible Preferred stock
Series G Preferred Stock [Member]
Stockholders' Equity
Convertible Preferred stock	5	5
Series I-2 Preferred Stock [Member]
Stockholders' Equity
Convertible Preferred stock

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts receivable	$ 12	$ 12
Preferred stock, par value	$ 0.001
Preferred stock, shares authorized	20,000,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares issued	6,933,861	6,057,132
Common stock, shares outstanding	6,933,861	6,057,132
Series B Preferred Stock [Member]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	250,000	250,000
Preferred stock, shares outstanding	250,000	250,000
Liquidation preference	$ 411	$ 396
Series D Preferred Stock [Member]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	50	50
Preferred stock, shares issued	43	43
Preferred stock, shares outstanding	43	43
Liquidation preference	$ 4,320	$ 4,320
Series G Preferred Stock [Member]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	5,000,000	5,000,000
Preferred stock, shares outstanding	5,000,000	5,000,000
Liquidation preference	$ 5,000	$ 5,000
Series I-1 Preferred Stock [Member]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	2,000	2,000
Preferred stock, shares issued	814	1,304
Preferred stock, shares outstanding	814	1,304
Liquidation preference	$ 814	$ 1,304
Series I-2 Preferred Stock [Member]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	4,310	4,310
Preferred stock, shares issued	4,310	4,310
Preferred stock, shares outstanding	4,310	4,310
Liquidation preference	$ 4,310	$ 4,310

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenues
Total revenues	$ 11,089,000	$ 7,456,000
Expenses
Cost of sales	4,069,000	2,122,000
Research and development	2,396,000	2,658,000
Selling and marketing	2,631,000	2,405,000
General and administrative	5,467,000	5,213,000
Total expenses	14,563,000	12,398,000
Loss from operations	(3,474,000)	(4,942,000)
Other income (expense)
Change in fair value of warrant liability	1,368,000	(1,068,000)
Interest expense	(48,000)	(59,000)
Miscellaneous income	44,000
Miscellaneous expense	(21,000)
Total other income (expense), net	1,343,000	(1,127,000)
Loss before provision for income taxes	(2,131,000)	(6,069,000)
Provision for income taxes	0	0
Net loss	(2,131,000)	(6,069,000)
Net loss applicable to common stockholders	$ (2,131,000)	$ (6,069,000)
Net loss per common share-basic	$ (0.33)	$ (1.46)
Net loss per common share-diluted	$ (0.33)	$ (1.46)
Weighted average shares outstanding-basic	6,388	4,158
Weighted average shares outstanding-diluted	6,388	4,158
Product
Revenues
Total revenues	$ 11,089,000	$ 7,456,000

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Preferred Stock [Member]Series B Convertible Preferred Stock [Member]	Preferred Stock [Member]Series G Convertible Preferred Stock [Member]	Preferred Stock [Member]Series I One Convertible Preferred Stock	Preferred Stock [Member]Series I Two Convertible Preferred Stock	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2016	$ 3,444	$ 4		$ 5			$ 101,898	$ (98,463)
Beginning balance, shares at Dec. 31, 2016		3,951	250	5,000	2	4
Issuance of common stock
for services	49						49
for services, shares		30
for cash	500						500
for cash, shares		286
Conversion of preferred stock, shares		215			(1)
Conversion of debt	2,756	$ 2					2,754
Conversion of debt, shares		1,575
Stock-based compensation	1,384						1,384
Net loss	(6,069)							(6,069)
Ending balance at Dec. 31, 2017	2,064	$ 6		$ 5			106,585	(104,532)
Ending balance, shares at Dec. 31, 2017		6,057	250	5,000	1	4
Issuance of common stock
for services	15						15
for services, shares		10
for cash	500	$ 1					499
for cash, shares		286
from exercise of options	160						160
from exercise of options, shares		141
Conversion of preferred stock, shares		280
Issuance of common stock for settlement of trade payables	248						248
Issuance of common stock for settlement of trade payables, shares		160
Stock-based compensation	1,681						1,681
Net loss	(2,131)							(2,131)
Ending balance at Dec. 31, 2018	$ 2,537	$ 7		$ 5			$ 109,188	$ (106,663)
Ending balance, shares at Dec. 31, 2018		6,934	250	5,000	1	4

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities
Net loss	$ (2,131)	$ (6,069)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	308	326
Stock-based compensation expense	1,681	1,384
Common stock issued for services	15	49
Change in fair value of warrant liability	(1,368)	1,068
Allowance for inventory obsolescence	(20)	135
Interest expense on bridge loan from related party	45	56
Gain on settlement of trade payables	(32)
Loss on disposal of property and equipment	25
Impairment of intangible assets	607	1,175
Changes in operating assets and liabilities
(Increase) decrease in accounts receivable	(186)	109
Increase in inventory	(287)	(129)
Decrease (increase) in prepaid expenses and other current assets	245	(361)
Increase in deposits and other assets	(4)	(16)
Decrease in accounts payable	(92)	(11)
Increase in accrued liabilities and long-term deferred rent	112	142
Net cash used in operating activities	(1,082)	(2,142)
Investing activities
Purchases of property and equipment	(185)	(112)
Payments for patent licenses and trademarks	(476)	(752)
Net cash used in investing activities	(661)	(864)
Financing activities
Proceeds from a bridge loan from a related party	2,000	2,700
Proceeds from issuance of common stock	500	500
Proceeds from exercise of options	160
Payments on financed insurance premiums	(146)
Net cash provided by financing activities	2,514	3,200
Net increase in cash	771	194
Cash, beginning of year	304	110
Cash, end of year	1,075	304
Supplemental disclosure of cash flow information
Cash paid for interest	3	1
Supplemental disclosure of non-cash investing and financing activities
Issuance of common stock for settlement of trade payables	248
Conversion of bridge loan from a related party		2,756
Financed insurance premiums	9	158
Lease incentives received for leasehold improvements and construction in progress	$ 179
Common Stock [Member]
Supplemental disclosure of non-cash investing and financing activities
Conversion of bridge loan from a related party		2
Bridge Loan [Member] | Common Stock [Member]
Supplemental disclosure of non-cash investing and financing activities
Conversion of bridge loan from a related party		$ 2,756

Organization and Significant Ac

Organization and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Significant Accounting Policies	1. Organization and Significant Accounting Policies Business Combination and Corporate Restructure BTHC III, Inc. (“BTHC III” or the “Company”) was organized in Delaware in June 2005 as a shell company to effect the reincorporation of BTHC III, LLC, a Texas limited liability company. On December 28, 2006, the Company effected a Share Exchange pursuant to which it acquired all of the stock of International Stem Cell Corporation, a California corporation (“ISC California”). After giving effect to the Share Exchange, the stockholders of ISC California owned 93.7% of issued and outstanding shares of common stock. As a result of the Share Exchange, ISC California is now the wholly-owned subsidiary, though for accounting purposes it was deemed to have been the acquirer in a “reverse merger.” In the reverse merger, BTHC III is considered the legal acquirer and ISC California is considered the accounting acquirer. On January 29, 2007, the Company changed its name from BTHC III, Inc. to International Stem Cell Corporation. Lifeline Cell Technology, LLC (“LCT”) was formed in the State of California on August 17, 2001. LCT is in the business of developing and manufacturing purified primary human cells and optimized reagents for cell culture. LCT’s scientists have used a technology, called basal medium optimization, to systematically produce products designed to culture specific human cell types and to elicit specific cellular behaviors. These techniques also produce products that do not contain non-human animal proteins, a feature desirable to the research and therapeutic markets. LCT distinguishes itself in the industry by having in place scientific and manufacturing staff with the experience and knowledge to set up systems and facilities to produce a source of consistent, standardized, non-human animal protein free cell products, some of which are suitable for FDA approval. On July 1, 2006, LCT entered into an agreement among LCT, ISC California and the holders of membership units and warrants. Pursuant to the terms of the agreement, all the membership units in LCT were exchanged for 133,334 shares of ISC California Common Stock and for ISC California’s assumption of LCT’s obligations under the warrants. LCT became a wholly-owned subsidiary of ISC California. Lifeline Skin Care, Inc. (“LSC”) was formed in the State of California on June 5, 2009 and is a wholly-owned subsidiary of ISC California. LSC develops, manufactures and markets cosmetic products, utilizing an extract derived from the Company’s human parthenogenetic stem cell and the Company’s proprietary targeted small molecule technology. Cyto Therapeutics Pty. Ltd. (“Cyto Therapeutics”) was registered in the state of Victoria, Australia, on December 19, 2014 and is a limited proprietary company and a wholly-owned subsidiary of the Company. Cyto Therapeutics is a research and development company for the Therapeutic Market, which is conducting clinical trials in Australia for the use of human parthenogenetic stem cell (hpSCs) in the treatment of Parkinson’s disease. Going Concern The Company has sustained recurring losses and needs to raise additional working capital. The timing and degree of any future capital requirements will depend on many factors. Currently, the Company’s burn rate is approximately $90,000 per month, excluding capital expenditures and patent costs averaging $55,000 per month. There can be no assurance that the Company will be successful in maintaining its normal operating cash flow and raising additional funds, and that such cash flows will be sufficient to sustain the Company’s operations through at least one year from the date the financial statements are available to be issued. Based on the above, there is substantial doubt about the Company’s ability to continue as a going concern. The consolidated financial statements were prepared assuming that the Company will continue as a going concern. The consolidated financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classification of liabilities that may result from the outcome of this uncertainty. Management’s plans in regard to these matters are focused on managing its cash flow, the proper timing of its capital expenditures, and raising additional capital or financing in the future. Basis of Presentation The Company is a biotechnology company focused on therapeutic and clinical product development with multiple long-term therapeutic opportunities and two revenue-generating subsidiaries with potential for increased future revenues. The Company has generated product revenues from the two commercial businesses of $11,089,000 and $7,456,000 for the years ended December 31, 2018 and 2017, respectively. The Company currently has no revenue generated from its principal operations in therapeutic and clinical product development through research and development efforts. Principles of Consolidation The Company’s consolidated financial statements include the accounts of International Stem Cell Corporation and its subsidiaries after intercompany balances and transactions have been eliminated. Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less when purchased to be cash equivalents. There were no cash equivalents as of December 31, 2018 and 2017. Inventory Inventory is accounted for using the average cost and first-in, first-out (FIFO) methods for Lifeline Cell Technology (LCT) cell culture media and reagents, average cost and specific identification methods for Lifeline Skin Care (LSC) products, and specific identification method for LCT products. Inventory balances are stated at the lower of cost or net realizable value. Laboratory supplies used in the research and development process are expensed as consumed. Inventory is reviewed periodically for product expiration and obsolescence and is adjusted accordingly. The value of the inventory that is not expected to be sold within twelve months of the year end is classified as non-current inventory on the consolidated balance sheets. Accounts Receivable Trade accounts receivable are recorded at the net invoice value and are not interest bearing. Accounts receivable primarily consist of trade accounts receivable from the sales of LCT’s products, timing of cash receipts by the Company related to LSC credit card sales to customers, as well as LSC trade receivable amounts related to spa and distributor sales. The Company considers receivables past due based on the contractual payment terms. The Company reviews its exposure to accounts receivable and reserves specific amounts if collectability is no longer reasonably assured. As of December 31, 2018 and 2017, the Company had an allowance for doubtful accounts totaling $12,000. Property and Equipment Property and equipment are stated at cost. The provision for depreciation and amortization is computed using the straight-line method over the estimated useful lives of the assets, generally over three to five years. The costs of major remodeling and leasehold improvements are capitalized and amortized over the shorter of the remaining term of the lease or the estimated life of the asset. Intangible Assets Intangible assets consist of acquired research and development rights used in research and development, and capitalized legal fees related to the acquisition, filing, maintenance, and defense of patents and trademarks. Patent or patent license amortization only begins once a patent license is acquired or a patent is issued by the appropriate authoritative bodies. In the period in which a patent application is rejected or efforts to pursue the patent are abandoned, all the related accumulated costs are expensed. Patents and other intangible assets are recorded at cost of $3,632,000 and $3,763,000 at December 31, 2018 and 2017, respectively, and are amortized on a straight-line basis over the shorter of the lives of the underlying patents or the estimated useful life of the license. Amortization expense for the years ended December 31, 2018 and 2017 amounted to $117,000 and $139,000, respectively, and is included in research and development expense. Accumulated amortization as of December 31, 2018 and 2017 was $958,000 and $841,000, respectively. Additional information regarding patents and patent licenses is included in Note 4. The Company recognized $607,000 and $1.2 million of impairment losses on its intangible assets during the years ended December 31, 2018 and 2017, respectively, due to abandonment of efforts to pursue certain patents or patented technologies. Long-Lived Asset Impairment The Company reviews long-lived assets for impairment when events or changes in business conditions indicate that their carrying value may not be recovered, and at least annually. The Company considers assets to be impaired and writes them down to estimated fair value if expected associated undiscounted cash flows are less than the carrying amounts. Fair value is the present value of the associated cash flows. Revenue Recognition Pursuant to the issuance by the Financial Accounting Standards Board (“FASB”) of Accounting Standards Codification (“ASC”), Revenue Recognition 1. Identify the contract with the customer 2. Identify the performance obligations in the contract 3. Determine the transaction price 4. Allocate the transaction price to the performance obligations in the contract 5. Recognize revenue when (or as) each performance obligation is satisfied Under ASC 606, the Company recognizes revenue when it satisfies a performance obligation by transferring control of the promised goods or services to its customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. The following table presents the Company’s revenue disaggregated by segment, product and geography, based on management’s assessment of available data (in thousands): Biomedical Market: Year Ended December 31, 2018 U.S. OUS* Total Revenues % of Total Revenues Biomedical products Cells $ 1,002 $ 405 $ 1,407 15 % Media 7,336 516 7,852 85 % Other 18 — 18 0 % Total $ 8,356 $ 921 $ 9,277 100 % *Outside the United States Year Ended December 31, 2017 U.S. OUS* Total Revenues % of Total Revenues Biomedical products Cells $ 1,181 $ 510 $ 1,691 33 % Media 2,967 533 3,500 67 % Other 9 — 9 0 % Total $ 4,157 $ 1,043 $ 5,200 100 % *Outside the United States Cosmetic Market: Year Ended December 31, 2018 Year Ended December 31, 2017 Total Revenues % of Total Revenues Total Revenues % of Total Revenues Cosmetic sales channels ecommerce $ 976 54 % $ 1,098 49 % Professional 836 46 % 1,153 51 % International — 0 % 5 0 % Total $ 1,812 100 % $ 2,256 100 % The Company's revenue consists primarily of sales of products from its two revenue-generating operating segments, the cosmetics products and biomedical products business segments. The cosmetic market segment markets and sells a line of luxury skincare products sold through three sales channels: ecommerce, professional, and international. The ecommerce channel sells direct to customers through online orders, while the professional sales are to spas, salons and other skincare providers. International sales are primarily through distributors. The biomedical market segment markets and sells primary human cell research products with two product categories, cells and media, both sold within and outside the United States. Contract terms for unit price, quantity, shipping and payment are governed by sales agreements, invoices or online order forms which the Company considers to be a customer's contract in all cases. The unit price is considered the observable stand-alone selling price for the arrangements. Any promotional or volume sales discounts are applied evenly to the units sold for purposes of calculating standalone selling price. Product sales generally consist of a single performance obligation that the Company satisfies at a point in time. The Company recognizes product revenue when the following events have occurred: (a) the Company has transferred physical possession of the products, (b) the Company has a present right to payment, (c) the customer has legal title to the products, and (d) the customer bears significant risks and rewards of ownership of the products. For LSC products, ecommerce sales are primarily paid through credit card charges, while professional and international sales are invoiced. The professional sales and biomedical products' standard payment terms for its customers are generally 30 days after the Company satisfies the performance obligations. For cosmetic products, the Company honors a 30-days return policy, but historical returns have been minimal and as such, the estimated allowance for sales returns was none and $10,000 as of December 31, 2018 and December 31, 2017 respectively. The Company elects to account for shipping and handling as activities to fulfill the promise to transfer the goods. As a result, no consideration is allocated to shipping and handling. Rather, the Company accrues the cost of shipping and handling upon shipment of the product, and all contract revenue is recognized at the same time. Variable Consideration The Company records revenue from customers in an amount that reflects the transaction price it expects to be entitled to after transferring control of those goods or services. From time to time, the Company offers sales promotions on its skincare products such as discounts and free product offers. Variable consideration is estimated at contract inception only to the extent that it is probable that a significant reversal of revenue will not occur and updated at the end of each reporting period as additional information becomes available. Contract Balances The Company records a receivable when it has an unconditional right to receive consideration after the performance obligations are satisfied. As of December 31, 2018 and December 31, 2017, accounts receivable, net, totaled $651,000 and $465,000, respectively. For the year ended December 31, 2018, the Company did not incur material impairment losses with respect to its receivables. Practical Expedients The Company has elected the practical expedient not to determine whether contracts with customers contain significant financing components. The Company pays commissions on certain sales for its biomedical and cosmetic market(s) once the customer payment has been received, which are accrued at the time of the sale. The Company generally expenses sales commissions when incurred because the amortization period would have been one year or less. These costs are recorded within sales and marketing expenses. In addition, the Company has elected to exclude sales taxes in consideration of the transaction price. Allowance for Sales Returns The Company’s cosmetic products have a 30-day product return guarantee and based on historical rate of returns from the years ended December 31, 2015 through 2017, the Company determined that there is a low probability that returns will occur. The returns that have historically occurred have not been significant and have been recognized as they occur as a reduction of revenue that is recognized as performance obligations are met. As of December 31, 2018, the Company has no allowance for sales returns compared to the prior year of $10,000. Cost of Sales Cost of sales consists primarily of salaries and benefits associated with employee efforts expended directly on the production of the Company’s products and include related direct materials, general laboratory supplies and allocation of overhead. Certain of the agreements under which the Company has licensed technology will require the payment of royalties based on the sale of its future products. Such royalties will be recorded as a component of cost of sales. Additionally, the amortization of license fees or milestone payments related to developed technologies used in the Company’s products will be classified as a component of cost of sales to the extent such payments become due in the future. Research and Development Costs Research and development costs, which are expensed as incurred, are primarily comprised of costs and expenses for salaries and benefits associated with research and development personnel, overhead and occupancy, contract services, and amortization of license costs for technology used in research and development with alternative future uses. Stock-Based Compensation The Company recognized stock-based compensation expense associated with stock options and other stock-based awards in accordance with the authoritative guidance for stock-based compensation. The cost of a stock-based award is measured at the grant date based on the estimated fair value of the award, and is recognized as expense on a straight-line basis, net of estimated forfeitures over the requisite service period of the award. The fair value of stock options is estimated using the Black-Scholes option valuation model, which requires the input of subjective assumptions, including price volatility of the underlying stock, risk-free interest rate, dividend yield, and expected life of the option. The fair value of restricted stock awards is based on the market value of the Company’s common stock on the date of grant. Fair Value Measurements Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Assets and liabilities that are measured at fair value are reported using a three-level fair value hierarchy that prioritizes the inputs used to measure fair value. This hierarchy maximizes the use of observable inputs and minimizes the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: Level 1 Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities; Level 2 Quoted prices in markets that are not active, or inputs that are observable, either directly or indirectly, for substantially the full term of the asset or liability; and Level 3 Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (supported by little or no market activity). Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The table below sets forth a summary of the Company’s liabilities which are measured at fair value on a recurring basis as of December 31, 2018 (in thousands). Total Level 1 Level 2 Level 3 LIABILITIES: Warrants to purchase common stock $ 1,745 $ — $ — $ 1,745 The table below sets forth a summary of the Company’s liabilities which are measured at fair value on a recurring basis as of December 31, 2017 (in thousands). Total Level 1 Level 2 Level 3 LIABILITIES: Warrants to purchase common stock $ 3,113 $ — $ — $ 3,113 The following table displays the rollforward activity of liabilities with inputs that are both significant to the fair value measurement and unobservable (supported by little or no market activity) (in thousands): Warrants common stock Beginning balance at December 31, 2016 $ 2,045 Adjustments to estimated fair value 1,068 Ending balance at December 31, 2017 3,113 Adjustments to estimated fair value (1,368 ) Ending balance at December 31, 2018 $ 1,745 Income Taxes The Company accounts for income taxes in accordance with applicable authoritative guidance, which requires the Company to provide a net deferred tax asset/liability equal to the expected future tax benefit/expense of temporary reporting differences between book and tax accounting methods and any available operating loss or tax credit carryforwards. Use of Estimates The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements. Significant estimates include patent life (remaining legal life versus remaining useful life), inventory carrying values, allowance for excess and obsolete inventories, allowance for sales returns and doubtful accounts, and transactions using the Black-Scholes option pricing model, e.g., warrants and stock options, as well as the Monte-Carlo valuation method for certain warrants. Actual results could differ from those estimates. Fair Value of Financial Instruments The Company believes that the carrying value of its cash and cash equivalents, receivables, accounts payable, accrued liabilities, and related party payable as of December 31, 2018 and 2017 approximate their fair values because of the short-term nature of those instruments. The fair value of certain warrants was determined at each issuance and reporting date and other applicable re-measurement dates in 2018 and 2017 using the Monte-Carlo valuation methodology. Income (Loss) Per Common Share The computation of net loss per common share is based on the weighted average number of shares outstanding during each period. The computation of diluted earnings per common share is based on the weighted average number of shares outstanding during the period plus the common stock equivalents, which would arise from the exercise of stock options and warrants outstanding using the treasury stock method and the average market price per share during the period. At December 31, 2018, there were 1,824,885 vested and 2,542,457 non-vested stock options outstanding and 3,951,052 warrants outstanding; and at December 31, 2017, there were 4,001,469 warrants, and 1,011,590 vested and 1,284,489 non-vested stock options outstanding. These stock options, warrants, and convertible preferred stock were not included in the diluted loss per share calculation because the effect would have been anti-dilutive. Refer to Note 6 for convertible preferred stock. Comprehensive Income Comprehensive income or loss includes all changes in stockholders’ equity except those resulting from investments by owners and distributions to owners. The Company did not have any items of comprehensive income or loss other than net loss from operations for the years ended December 31, 2018 and 2017. Recent Accounting Pronouncements I n August 2018, the FASB issued Accounting Standards Update (“ASU”) 2018-13, “Fair Value Measurement (Topic 820), “Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement” (“ASU 2018-13), which removes the valuation processes for Level 3 fair value measurements and adds the disclosure for the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. The updated standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The Company is currently evaluating the impact of the adoption of this accounting standard update. In June 2018, the FASB issued ASU 2018-07, “Compensation – Stock Compensation (Topic 718), Improvements to Nonemployee Share-Based Payment Accounting.” I n July 2017, the FASB issued ASU 2017-11, “Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), and Derivatives and Hedging (Topic 815 ). ASU 2017-11 changes the classification analysis of certain equity-linked financial instruments (or embedded features) with down round features and requires entities that present earnings per share (“EPS”) in accordance with Topic 260 to recognize the effect of the down round feature when triggered with the effect treated as a dividend and as a reduction of income available to common shareholders in basic EPS. The updated standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. In February 2016, the FASB issued ASU No. 2016-02, Leases

Inventory

Inventory	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Inventory	2. Inventory The components of inventories are as follows (in thousands): December 31, December 31, 2018 2017 Raw materials $ 656 $ 609 Work in process 590 472 Finished goods 1,276 1,154 Total 2,522 2,235 Less: allowance for inventory excess and obsolescence (216 ) (236 ) Inventory, net $ 2,306 $ 1,999

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2018
Property Plant And Equipment [Abstract]
Property and Equipment	3. Property and Equipment Property and equipment consists of the following (in thousands): December 31, December 31, 2018 2017 Machinery and equipment $ 1,614 $ 1,459 Computer equipment 251 429 Office equipment 215 214 Leasehold improvements 996 805 Construction in progress 45 — 3,121 2,907 Less: accumulated depreciation and amortization (2,652 ) (2,586 ) Property and equipment, net $ 469 $ 321 Depreciation and amortization expense for the years ended December 31, 2018 and 2017 were $191,000 and $187,000, respectively.

Patent Licenses

Patent Licenses	12 Months Ended
	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Patent Licenses	4. Patent Licenses On December 31, 2003, LCT entered into an Option to License Intellectual Property and was subsequently acquired by Astellas Pharma Inc. (“Astellas"), On May 14, 2004, LCT amended the licensing agreement with Astellas for the exclusive worldwide patent rights for the following Astellas technologies: UMass IP, ACT IP and Infigen IP. The additional license fees paid were $400,000. On February 7, 2013, the Company and Astellas entered into Amended and Restated License Agreements (the “Amendment”) for the purpose of completely amending and restating the terms of the license agreements. Under the terms of the Amendment, the Company acquired exclusive world-wide rights to all human therapeutic uses and cosmetic uses from Astellas and Infigen’s early work on parthenogenic-derived embryonic stem cells, as well as certain rights to patents covering Single Blastomere technology. Pursuant to the Amendment, all minimum R&D requirements and all milestone payments due to Astellas under the Exclusive License Agreement have been eliminated. The Company will no longer pay any royalties under the ACT IP Agreement and Infigen IP Agreement. The obligation to pay royalties that ranged from 6%-12% under the UMass IP Agreement has been reduced to 0.25% of the net sales of products using technology covered by the UMass IP Agreement; and the obligation to pay a minimum annual license fee of $150,000 has been reduced to $75,000 annually, payable in two installments to Astellas. Total license fees paid were $75,000 for each of the years ended December 31, 2018 and 2017. As of December 31, 2018, the total amounts capitalized related to the acquired Astellas licenses were $747,000, and $2,885,000 related to other patent acquisition costs and trademarks. At December 31, 2018, future amortization expense related to the intangible assets subject to amortization is expected to be as follows (in thousands): Amount 2019 $ 96 2020 79 2021 79 2022 79 2023 79 Thereafter 2,179 Total $ 2,591

Advances

Advances	12 Months Ended
	Dec. 31, 2018
Advances [Abstract]
Advances	5. Advances On June 18, 2008, the Company entered into an agreement with BioTime, Inc. (“BioTime”), where BioTime will pay an advance of $250,000 to Lifeline Cell Technology, a wholly-owned subsidiary of International Stem Cell Corporation, to produce, make, and distribute Joint Products. The $250,000 advance will be paid down with the first $250,000 of net revenues that otherwise would be allocated to LCT under the agreement. As of December 31, 2018, no revenues were realized from this agreement. December 31, December 31, 2018 2017 BioTime, Inc. (in thousands) $ 250 $ 250

Capital Stock

Capital Stock	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Capital Stock	6. Capital Stock As of December 31, 2018, the Company is authorized to issue 120,000,000 shares of common stock, $0.001 par value per share, and 20,000,000 shares of preferred stock, $0.001 par value per share. Preferred Stock Transactions Series B Preferred Stock On May 12, 2008, to obtain funding for working capital, the Company entered into a series of subscription agreements with five accredited investors for the sale of a total of 400,000 Series B Units, each Series B Unit consisting of one share of Series B Preferred Stock (“Series B Preferred”) and two Series B Warrants (“Series B Warrants”) to purchase common stock for each $1.00 invested. The total purchase price received by the Company was $400,000. The Series B Preferred is convertible into shares of common stock at the initial conversion ratio of 0.0134 shares of common stock for each share of Series B Preferred converted (which was established based on an initial conversion price of $75.00 per share), and the Series B Warrants were exercisable at $75.00 per share until five years from the issuance of the Series B Warrants, which expired unexercised in May 2013. The Series B Preferred contain anti-dilution clauses whereby, if the Company issues equity securities or securities convertible into equity at a price below the conversion price of the Series B Preferred, such conversion price shall be adjusted downward to equal the price of the new securities. The Series B Preferred has a priority (senior to the shares of common stock and Series I Preferred) on any sale or liquidation of the Company equal to the purchase price of the Series B Units, plus a liquidation premium of 6% per year. If the Company elects to declare a dividend in any year, it must first pay to the Series B Preferred holder a dividend equal to the amount of the dividend the Series B Preferred holder would receive if the Series B Preferred were converted just prior to the dividend declaration. Each share of Series B Preferred has the same voting rights as the number of shares of common stock into which it would be convertible on the record date. As of December 31, 2018 and 2017, there were 250,000 shares of the Series B Preferred issued and outstanding. In December 2016, the Company issued Restricted Stock to its non-employee directors at a price of $1.08. Accordingly, such transactions triggered adjustments in the current conversion price of the Series B Preferred to $1.08. Series D Preferred Stock On December 30, 2008, the Company entered into a Series D Preferred Stock Purchase Agreement (the “Series D Agreement”) with accredited investors (the “Investors”) and sold 43 shares of Series D Preferred Stock (“Series D Preferred”) at a price of $100,000 per Series D Preferred share. Ten shares of the Series D Preferred were issued to X-Master Inc., which is a related party and affiliated with the Company’s Chief Executive Officer and Co-Chairman of the Board of Directors, Dr. Andrey Semechkin and Dr. Russell Kern, Executive Vice President and Chief Scientific Officer and a director; and 33 shares of the Series D Preferred were issued to Dr. Andrey Semechkin. As of December 31, 2018 and 2017, there were 43 shares of the Series D Preferred issued and outstanding. The Series D Preferred was initially convertible into shares of common stock at $37.50 per share, resulting in an initial conversion ratio of 2,667 shares of common stock for every share of Series D Preferred. The Series D Preferred has an anti-dilution clause whereby, if the Company issues equity securities or securities convertible into equity at a price below the conversion price of the Series D Preferred, the conversion price of the Series D Preferred shall be adjusted downward to equal the price of the new securities. The Series D Preferred has priority over the Series B Preferred Stock, Series G Preferred Stock, Series I-1 Preferred Stock, Series I-2 Preferred Stock and common stock on the proceeds from any sale or liquidation of the Company in an amount equal to the purchase price of the Series D Preferred. In March 2016, the Company issued Series I Preferred Stock which had an initial conversion price of $1.75, as well as three series of warrants. Accordingly, such transaction triggered an adjustment in the current conversion price of the Series D Preferred Stock to $1.75. Series G Preferred Stock On March 9, 2012, the Company entered into a Series G Preferred Stock Purchase Agreement with AR Partners, LLC (the “Purchaser”) to sell 5,000,000 shares of Series G Preferred Stock (“Series G Preferred”) at a price of $1.00 per Series G Preferred share, for a total purchase price of $5,000,000. The Purchaser is an affiliate of Dr. Andrey Semechkin, the Company’s Co-Chairman and Chief Executive Officer, and Dr. Russell Kern, Executive Vice President and Chief Scientific Officer and a director. The Series G Preferred was initially convertible into shares of common stock at $60.00 per share, resulting in an initial conversion ratio of 0.0167 shares of common stock for every share of Series G Preferred. The conversion price may be adjusted for stock splits and other combinations, dividends and distributions, recapitalizations and reclassifications, exchanges or substitutions and is subject to a weighted-average adjustment in the event of the issuance of additional shares of common stock below the conversion price. The Series G Preferred shares have priority over the Series B Preferred, Series I-1 Preferred, Series I-2 Preferred and common stock on the proceeds from any sale or liquidation of the Company in an amount equal to the purchase price of the Series G Preferred, but such payment may be made only after payment in full of the liquidation preferences payable to holders of any shares of Series D Preferred then outstanding. Each share of Series G Preferred has the same voting rights as the number of shares of common stock into which it would be convertible on the record date. As long as there are at least 1,000,000 shares of Series G Preferred outstanding, the holders of Series G Preferred have (i) the initial right to propose the nomination of two members of the Board, at least one of which such nominees shall be subject to the approval of the Company’s independent directors, for election by the stockholders at the Company’s next annual meeting of stockholders, or, elected by the full board of directors to fill a vacancy, as the case may be, and (ii) the right to approve any amendment to the certificate of incorporation, certificates of designation or bylaws, in manner adverse to the Series G Preferred, alter the percentage of board seats held by the Series G Preferred directors or increase the authorized number of shares of Series G Preferred. At least one of the two directors nominated by holders of the Series G Preferred shall be independent based on the NASDAQ listing requirements. As of December 31, 2018 and 2017, there were 5,000,000 shares of the Series G Preferred issued and outstanding. Series I Preferred Stock On March 9, 2016, pursuant to a Securities Purchase Agreement (the “Series I Agreement”), with three investors, which included two institutional investors and Andrey Semechkin, the Company's Chief Executive Officer and Co-Chairman providing for issuance (the "Offering") of (i) 2,000 shares of Series I-1 convertible preferred stock (the “Series I-1 Preferred Stock”) issuable to the institutional investors at a price of $1,000 per share, (ii) 4,310 shares of Series I-2 convertible preferred stock (the “Series I-2 Preferred Stock”, and together with the Series I-1 Preferred Stock, the “Series I Preferred Stock”) issuable to Andrey Semechkin at a price of $1,000 per share, (iii) Series A warrants (the “Series A Warrants”) to purchase up to approximately 3.6 million shares of common stock for an initial exercise price of $3.64 per share with a term of five years, (iv) Series B warrants (the “Series B Warrants”) to purchase up to approximately 3.6 million shares of common stock for an initial exercise price of $1.75 per share with a term of six months, and (v) Series C warrants (the “Series C Warrants”, together with the Series A Warrants and the Series B Warrants, collectively, the “Investor Warrants”) to purchase up to approximately 3.6 million shares of common stock for an initial exercise price of $1.75 per share with a term of twelve months. The Closing of the Offering occurred on March 15, 2016 (the “Closing Date”). The Series I Agreement also contains representations, warranties, indemnification and other provisions customary for transactions of this nature. The Company received cash proceeds of $2.5 million on the closing date. On September 15, 2016, the remaining unexercised Series B Warrants then outstanding expired unexercised. On March 15, 2017, the remaining unexercised Series C Warrants then outstanding expired unexercised. Rodman & Renshaw, a unit of H.C. Wainwright & Co., LLC. (the “Placement Agent”) acted as the exclusive placement agent for the Offering pursuant to a placement agency engagement letter, dated as of March 9, 2016, by and between the Placement Agent and the Company (the Engagement Letter”). Upon the closing of the Offering, pursuant to the Engagement Letter, the Placement Agent received a placement agent fee of $200,000 and a warrant to purchase approximately 343,000 shares of common stock (the “Placement Agent Warrant”, together with the Investor Warrants, the “Warrants”) as well as the reimbursement of fees and expenses up to $50,000. Similar to the Series A Warrant, the Placement Agent Warrant will have an initial exercise price of $3.64 per share, be immediately exercisable and will terminate on five years after the date of issuance. Subject to certain ownership limitations with respect to the Series I-1 Preferred Stock, the Series I Preferred Stock is convertible at any time into shares of common stock at an initial conversion price of $1.75 per share. The Series I Preferred Stock is non-voting, is only entitled to dividends in the event that dividends are paid on the common stock, and will not have any preferences over the common stock, except that the Series I Preferred Stock shall have preferential liquidation rights over the common stock. Other than the Series I-1 Preferred Stock having a beneficial ownership limitation, the Series I-1 Preferred Stock and Series I-2 Preferred Stock are substantially identical. The conversion price of the Series I Preferred Stock is subject to certain resets as set forth in the Certificates of Designation, including the date of any future amendment to the certificate of incorporation with respect to a reverse stock split, the effectiveness dates of the registration statements and, in certain instances, the six and twelve month anniversaries of the Closing Date. During the years ended December 31, 2018 and 2017, the investors converted 490 and 376 shares respectively, of the Series I Preferred Stock into 280,000 and 214,700 shares respectively, of the Company’s common stock. As of December 31, 2018 and 2017, there were 5,124 and 5,614 shares of Series I Preferred Stock outstanding, respectively. See Note 9, Stock Options and Warrants, for detailed discussion of the anti-dilution provisions of the Series A and Placement Agent Warrants. Common Stock Transactions September 2018 Private Placement On September 21, 2018, to obtain funding for working capital, the Company entered into a private placement transaction with an accredited investor for the sale of a total of 285,714 shares of the Company’s common stock for an aggregate purchase price of $500,000 at $1.75 per share. Trade Payables Settlement On October 2, 2018, the Company issued 160,192 shares of common stock to a trade creditor at $1.75 per share in satisfaction of $280,000 owed to the creditor. The shares issued in the transaction were issued in a private transaction in reliance upon the exemption from registration in Section 4(a)(2) of the Securities Act of 1933. A gain of $32,000 was recognized on the settlement as other income in the consolidated statement of operations for the year ended December 31, 2018. Reserved Shares At December 31, 2018, the Company had shares of common stock reserved for future issuance as follows: Options outstanding 4,367,342 Options available for future grant 5,082,901 Convertible preferred stock 6,120,725 Warrants 3,951,052 19,522,020

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	7. Related Party Transactions Other than with respect to the purchases of Series D Preferred, Series G Preferred, Series I Preferred, and common stock transactions discussed above, the Company’s related party transactions were for a facility lease and working capital bridge loans. During the first quarter of 2011, the Company executed an operating lease for its corporate offices with S Real Estate Holdings LLC. S Real Estate Holdings LLC is owned by Dr. Russell Kern, the Company’s Executive Vice President and Chief Scientific Officer and a director and was previously owned by Dr. Andrey Semechkin, the Company’s Chief Executive Officer and Co-Chairman of the Board of Directors. The lease agreement was negotiated at arm’s length and was reviewed by the Company’s outside legal counsel. The terms of the lease were reviewed by a committee of independent directors, and the Company believes that, in total, those terms are at least as favorable to the Company as could be obtained for comparable facilities from an unaffiliated party. In March 2017 the Company signed an amendment to the lease agreement to extend the term of the lease until 2019 and include annual adjustments to the monthly lease payments. For the years ended December 31, 2018 and 2017, the Company recorded $160,000 and $154,000, respectively, in rent expense that was related to the facility lease arrangement with related parties. Between January 12, 2017 and September 1, 2017, to obtain funding for working capital, the Company borrowed a total of $2,700,000 from Dr. Andrey Semechkin, the Company’s Chief Executive Officer and Co-Chairman of the Board of Directors, and issued an unsecured, non-convertible promissory note in the principal amount of $2,700,000 (the “2017 Note”) to Dr. Andrey Semechkin. The principal amount under the 2017 Note accrues interest at a rate of three and a half percent (3.50%) per annum was due and payable September 1, 2017. On December 7, 2017, to obtain funding for working capital purposes and to satisfy the indebtedness incurred on September 1, 2017, the Company entered into a Note Conversion and Stock Purchase Agreement (the “Agreement”) with Dr. Andrey Semechkin. Pursuant to the Agreement, the Company agreed to issue Dr. Semechkin a total of 1,860,810 shares of Common Stock at a conversion price and a purchase price of $1.75 per share in return for cancellation and surrender of the note issued to him by the Company on September 1, 2017 with a principal amount of $2,700,000 and all accrued and unpaid interest on the note of $56,000 and payment of an additional $500,000 by Dr. Semechkin to the Company. Between March 6, 2018 and August 8, 2018, to obtain funding for working capital purposes, the Company borrowed a total of $2,000,000 from Dr. Andrey Semechkin and issued an unsecured non-convertible promissory note in the principal amount of $2,000,000 (the “Note”) to Dr. Andrey Semechkin (the “Noteholder”). The outstanding principal amount under the Note accrued interest at a rate of four percent (4%) per annum. The Note was due and payable November 1, 2018 and on November 12, 2018, to satisfy the indebtedness incurred on the Note, an amendment to the Note was entered into extending the due date to January 15, 2019. As of December 31, 2018, the principal amount of $2,000,000 and accrued interest of $45,000 remained outstanding. See Note 12, Subsequent Events.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	8. Income Taxes The Company accounts for income taxes in accordance with applicable authoritative guidance, which requires the Company to provide a net deferred tax asset/liability equal to the expected future tax benefit/expense of temporary reporting differences between book and tax accounting methods and any available operating loss or tax credit carryforwards. The Company has available at December 31, 2018, net operating loss carryforwards of approximately $67.2 million, which may be applied against future taxable income and will expire in various years through 2038. However, any net operating loss carryforwards generated in 2018 and future years will not expire and are carried forward indefinitely. At December 31, 2017, the Company had net operating loss carryforwards of approximately $ 64.9 million The amount of and ultimate realization of the benefits from the operating loss carryforwards for income tax purposes is dependent, in part, upon the tax laws in effect, the future earnings of the Company, and other future events, the effects of which cannot be determined at this time. Because of the uncertainty surrounding the realization of the loss carryforwards, the Company has established a valuation allowance equal to the tax effect of the loss carryforwards, research and development credits, and accruals; therefore, no net deferred tax asset has been recognized. A reconciliation of the statutory Federal income tax rate and the effective income tax rate for the years ended December 31, 2018 and 2017 follows: December 31, December 31, 2018 2017 Statutory federal income tax rate 21 % 35 % Permanent items 6 % (11 )% State income taxes, net of federal taxes 4 % (7 )% Foreign (2 )% (3 )% Change in valuation allowance (27 )% 175 % Change in tax rates 0 (189 )% Tax credits claimed (1 )% 0 % Other (1 )% 0 % Effective income tax rate 0 % 0 % The Company files income tax returns in the U.S. federal jurisdiction and various states. With few exceptions, the Company is no longer subject to U.S. federal, state and local income tax examinations by tax authorities for years before 2014. The Company does not have any material uncertain tax positions as of December 31, 2018 and 2017. The Company does not believe it is reasonably possible that the total amount of unrecognized tax benefits as of December 31, 2018 will materially change in the next 12 months. The Company may be subject to IRC Code Sections 382 and 383, which could limit the amount of the net operating loss and tax credit carryovers that can be used in future years. The Company has not completed a study to assess whether an ownership change has occurred, as defined by IRC Code Sections 382 and 383, or whether there have been ownership changes since the Company’s formation due to the complexity and cost associated with such a study, and the fact that there may be additional such ownership changes in the future. The Company estimates that if such a change did occur, the federal and state net operating loss carryforwards and research and development credit carryforwards that can be utilized in the future will be significantly limited. There can be no assurance that the Company will ever be able to realize the benefit of some or all of the federal and state loss carryforwards or the credit carryforwards, either due to ongoing operating losses or due to ownership changes, which limit the usefulness of the loss carryforwards. During the year ended December 31, 2017, the Company had a net decrease in deferred tax asset of $8,819,000. This change is a result of current year activity as well as a change in the federal tax rates. The change as a result of current year activity is an increase in deferred tax assets of $724,000. This increase was offset by a $9,543,000 decrease due to a remeasurement of the deferred tax asset based on new tax rates established through the Tax Cuts and Jobs Act passed December 22, 2017. The remeasurement was a provisional estimate under Staff Accounting Bulletin (“SAB”) 118 that could be revised based on any additional guidance issued by the U.S. Treasury Department, the U.S. Internal Revenue Service, and other standard-setting bodies. This new law did not have a significant impact on the Company’s consolidated financial statements for the year ended December 31, 2017 because the Company maintains a valuation allowance on the entirety of its deferred tax assets. However, the reduction of the U.S. federal corporate tax rate from 35% to 21% resulted in a remeasurement of the deferred tax asset reflected in the tax rate reconciliation below as well as the deferred tax asset listed above. Significant components of deferred tax assets and liabilities are as follows (in thousands): December 31, December 31, 2018 2017 Net operating loss carryforwards $ 17,569 $ 16,842 Stock based compensation 2,437 2,695 Research and development tax credit 2,729 2,696 Other 260 192 Non-current deferred tax assets 22,995 22,425 Valuation allowances (22,995 ) (22,425 ) Net deferred tax assets $ — $ — The components of the provision for income taxes were as follows: December 31, December 31, 2018 2017 Current $ — $ — Deferred — — Total $ — $ — During the preparation of the 2018 income tax provision, the Company completed its analysis to determine the effect of the Tax Act and recorded no additional adjustments.

Stock Options and Warrants

Stock Options and Warrants	12 Months Ended
	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options and Warrants	9. Stock Options and Warrants Stock Options The Company adopted the 2006 Equity Participation Plan (the “2006 Plan”), which provides for the grant of stock options, restricted stock and other equity based awards. Awards for up to 100,000 shares could be granted to employees, directors and consultants under this Plan. The options granted under the 2006 Plan could be either qualified or non-qualified options. Options may be granted with different vesting terms and expire no later than 10 years from the date of grant. The 2006 Plan expired on November 16, 2016. Options and other equity based awards granted to the expiration of the 2006 Plan will continue in effect until the option or award is exercised or terminates pursuant to its terms. No new awards may be granted under the 2006 Plan following its expiration. In April 2010, the Company adopted the 2010 Equity Participation Plan (the “2010 Plan”), which provides for the grant of stock options, restricted stock and other equity based awards. Awards of up to 9,700,000 shares may be granted to employees, directors and consultants under the 2010 Plan. The options granted under the 2010 Plan may be either qualified or non-qualified options. Options may be granted with different vesting terms and expire no later than 10 years from the date of grant. In November and December of 2009, the Company issued non-qualified stock options to purchase 68,384 shares of common stock outside the 2006 and 2010 option plans to certain employees and consultants. These options vest over 50 months and expire no later than 10 years from the date of grant. As of December 31, 2018, 12,634 options remain outstanding and a total of 55,750 options were exercised, canceled, or expired. Total stock-based compensation expense for the years ended December 31, 2018 and 2017 was comprised of the following (in thousands): Years Ended December 31, 2018 2017 Cost of sales $ 57 $ 23 Research and development 641 637 Selling and marketing 54 41 General and administrative 929 683 $ 1,681 $ 1,384 The per share weighted-average grant-date fair value of options granted during the years ended December 31, 2018 and 2017 was $1.17, and $0.93, respectively. Unrecognized compensation expense related to stock options as of December 31, 2018 was $2.8 million, which is expected to be recognized over a weighted average period of approximately 1.8 years. In accordance with applicable authoritative guidance, the Company is required to establish assumptions and estimates of the fair value of stock options granted, as well as using a valuation model to calculate the fair value of stock-based awards. The Company uses the Black-Scholes option-pricing model to determine the fair-value of stock-based awards. All options are amortized over the requisite service periods. The fair value of options granted is estimated at the date of grant using a Black-Scholes option-pricing model with the following weighted-average assumptions for the years ended December 31, 2018 and 2017: Year Ended Year Ended December 31, December 31, 2018 2017 Significant assumptions (weighted average): Risk-free interest rate at grant date 2.72 % 1.95 % Expected stock price volatility 92.68 % 96.71 % Expected dividend payout 0 % 0 % Expected option life based on management's estimate 5.70 yrs 5.71 yrs Additional information regarding options outstanding under our option plans as of December 31, 2018 is as follows: Options Outstanding Options Exercisable and Vested Weighted Average Weighted Average Remaining Remaining Number Contractual Life Weighted Average Number Contractual Life Weighted Average Exercise Prices Outstanding (Years) Exercise Price Exercisable (Years) Exercise Price $1.09-$1.49 667,059 8.28 $ 1.11 385,903 8.32 $ 1.12 $1.50-$1.55 996,944 9.20 $ 1.51 250,694 9.20 $ 1.51 $1.56-$1.59 1,354,389 9.62 $ 1.58 228,138 9.62 $ 1.58 $1.60-$3.03 452,594 8.22 $ 2.03 283,299 7.99 $ 2.09 $3.04-$289.50 883,722 6.91 $ 13.45 664,217 6.80 $ 16.65 4,354,708 8.62 $ 3.95 1,812,251 8.00 $ 7.08 Transactions involving stock options issued to employees, directors and consultants under the 2006 Plan, the 2010 Plan and outside the plans are summarized below. Options issued have a maximum life of 10 years. The following table summarizes the changes in options outstanding and the related exercise prices for the Company’s common stock options issued: Number of Weighted Options Weighted Average Aggregate Under Average Remaining Intrinsic 2006 Plan and Price Per Contractual Value 2010 Plan Share Term (in thousands) Outstanding at December 31, 2016 1,460,076 $ 13.21 Granted 1,145,568 $ 1.14 Exercised — $ — Canceled or expired (360,295 ) $ 5.80 Outstanding at December 31, 2017 2,245,349 $ 8.25 Granted 2,568,842 $ 1.56 Exercised (140,968 ) $ 1.13 Canceled or expired (318,515 ) $ 16.21 Outstanding at December 31, 2018 4,354,708 $ 3.95 8.62 years $ 299 Vested and expected to vest at December 31, 2018 4,056,445 $ 4.12 8.58 years $ 290 Exercisable at December 31, 2018 1,812,251 $ 7.08 8.00 years $ 162 Weighted Number of Weighted Average Aggregate Options Issued Average Exercise Remaining Intrinsic Outside Price Per Contractual Value the Plan Share Term (in thousands) Outstanding, vested and exercisable at December 31, 2016 50,730 $ 92.31 Granted — $ — Exercised — $ — Canceled or expired — $ — Outstanding, vested and exercisable at December 31, 2017 50,730 $ 92.31 Granted — $ — Exercised — $ — Canceled or expired (38,096 ) $ 93.00 Outstanding, vested and exercisable at December 31, 2018 12,634 $ 90.23 0.90 years $ — During the fiscal year ended December 31, 2018, four optionees exercised 140,968 options at a weighted average exercise price of $1.13 for a total exercise price of $160,000. On the various dates of exercise, the aggregate intrinsic value of the options was $60,000 or a weighted average of $0.42 per share. Restricted Stock Awards Restricted stock awards are grants that entitle the holder to acquire shares of common stock at zero or a fixed price, which is typically nominal. The Company accounts for the restricted stock awards as issued and outstanding common stock, even though the shares covered by a restricted stock award cannot be sold, pledged, or otherwise disposed of until the award vests and any unvested shares may be reacquired by the Company for the original purchase price following the awardee’s termination of service. The following table summarizes the changes in restricted stock award activity and related weighted average grant date fair values for the Company’s awards issued during the years ended December 31, 2018 and 2017: Restricted Stock Issued from the Weighted 2006 Average Grant Date 2010 Plan Fair Value Unvested at December 31, 2016 — $ — Granted 30,643 $ 1.60 Vested (30,643 ) $ 1.60 Forfeited — $ — Unvested at December 31, 2017 — $ — Granted 9,855 $ 1.55 Vested (9,855 ) $ 1.55 Forfeited — $ — Unvested at December 31, 2018 — $ — The fair value of the restricted stock awards is based on the market value of the common stock on the date of grant. The total grant-date fair value of restricted stock awards vested during the years ended December 31, 2018 and 2017 was approximately $15,000 and $49,000, respectively. The Company recognized approximately $15,000 and $49,000 of stock-based compensation expense related to the restricted stock awards for the years ended December 31, 2018 and 2017. As of December 31, 2018 and 2017, there was no unrecognized compensation costs related to unvested awards. Warrants Warrants Issued with Preferred Stock Warrants issued in connection with the October 2014 Financing The Company has accounted for the warrants in accordance with current accounting guidance, which defines how freestanding contracts that are indexed to and potentially settled in a Company’s own stock should be measured and classified. The authoritative accounting guidance prescribes that only warrants issued under contracts that cannot be net-cash settled and are both indexed to and settled in the Company’s common stock can be classified as equity. As the Series A, Series B and Series C Warrants and Placement Agent Warrant agreements did not meet the specific conditions for equity classification, the Company was required to classify the fair value of the warrants issued as a liability, with subsequent changes in fair value to be recorded as income (loss) in the consolidated statement of operations upon revaluation of the fair value of warrant liability at each reporting period. Valuation of the Warrants was estimated at issuance and each reporting date, using the Monte-Carlo simulation model. As of December 31, 2016, all Series A, B and C Warrants were exercised or expired unexercised. The following assumptions were used as inputs to the model at December 31, 2018: for the Placement Agent Warrants, stock price of $1.53 and warrant exercise price of $1.75 as of the valuation date; the Company’s historical stock price volatility of 94.2%; risk free interest rate on U.S. treasury notes of 2.59%; warrant expiration of 1.29 years; and a zero dividend rate; simulated as a daily interval and anti-dilution impact if the Company had to raise capital below $1.75 per share. During the years ended December 31, 2018 and 2017, the Company recorded a net change in fair value of warrant liability of $1,000 income and $0, respectively, in the consolidated statements of operations related to the warrants from the October 2014 financing. Placement Agent Warrants Price Adjustment – The Warrants are immediately exercisable and the exercise price of the Warrants is subject to certain reset adjustments as set forth in the forms of Warrant, including the date of the amendment to the Company’s certificate of incorporation with respect to any reverse stock split, the effectiveness dates of the registration statements and the six and twelve month anniversaries of the date of issuance of the Warrants. The Company’s registration statement on Form S-1 filed on November 3, 2014 with the SEC became effective on November 25, 2014. Pursuant to the terms of the respective warrant agreements, the exercise price of the Placement Agent Warrants were reset at $1.75 per share. As of December 31, 2018, 2,483 of the Placement Agent Warrants remained outstanding. Warrants issued in connection with the March 2016 Financing The Company has accounted for the warrants in accordance with current accounting guidance, which defines how freestanding contracts that are indexed to and potentially settled in a Company’s own stock should be measured and classified. The authoritative accounting guidance prescribes that only warrants issued under contracts that cannot be net-cash settled and are both indexed to and settled in the Company’s common stock can be classified as equity. As the Series A, Series B and Series C Warrants and Placement Agent Warrant agreements did not meet the specific conditions for equity classification, the Company was required to classify the fair value of the warrants issued as a liability, with subsequent changes in fair value to be recorded as income (loss) in the consolidated statement of operations upon revaluation of the fair value of warrant liability at each reporting period. Unexercised portions of the Series B and C Warrants have expired unexercised as of December 31, 2018. Valuation of the Warrants was estimated at issuance and at December 31, 2017 and 2018 using the Monte-Carlo simulation model. The following assumptions were used as inputs to the model at December 31, 2018: for Series A Warrants and the Placement Agent Warrants, stock price of $1.53 and warrant exercise price of $1.75 as of the valuation date; the Company’s historical stock price volatility of 94.2%; risk free interest rate on U.S. treasury notes of 2.48%; warrant expiration of 2.21 years; and a zero dividend rate; simulated as a daily interval and anti-dilution impact if the Company had to raise capital below $1.75 per share. During the years ended December 31, 2018 and December 31, 2017, the Company recorded a net change in fair value of warrant liability of $1.4 million income and a $1.1 million expense, respectively, in the consolidated statements of operations related to the warrants from the March 2016 financing. Series A and Placement Agent Warrants Price Adjustment – The Warrants are immediately exercisable and the exercise price of the Warrants is subject to certain reset adjustments as set forth in the forms of Warrant, including the date of the amendment to the Company’s certificate of incorporation with respect to any reverse stock split, the effectiveness dates of the registration statements and (in certain events) upon the six and twelve month anniversaries of the date of issuance of the Warrants. Pursuant to the terms of a note conversion and stock purchase agreement in December 2017 with Dr. Andrey Semechkin, the exercise price of the Series A Warrants and the Placement Agent Warrants were reset at $1.75 per share. At December 31, 2018, 3,948,569 of the Series A Warrants and Placement Agent Warrants remained outstanding. Warrants Issued with Common Stock 2013 Securities Purchase Agreements for Common Stock In conjunction with the Company’s sale of 67,500 shares of common stock on January 22, 2013, the Company issued warrants convertible into 33,750 shares of common stock at an exercise price of $30.00 per share. The warrants have a five-year term. These warrants were held by Dr. Andrey Semechkin and Dr. Simon Craw, the Company’s Co-Chairman and Chief Executive Officer and the Company’s former Executive Vice President Business Development, respectively. These warrants expired unexercised in January 2018. On March 12, 2013 the Company issued warrants convertible into 16,667 shares of common stock in conjunction with the sale of 33,334 shares of common stock. These warrants have a five-year term and an exercise price of $30.00 per share. Dr. Andrey Semechkin, the Company’s Co-Chairman and Chief Executive Officer is the holder of 1,667 of these warrants. These warrants expired unexercised in March 2018. Share data related to warrant transactions for the years ended December 31, 2018 and 2017 were as follows: Common Stock Common Stock March 2016 Financing October 2014 Financing Series A Series B Series C Placement Agent Series A Series B Series C Placement Agent Outstanding, December 31, 2016 3,605,713 — 3,319,999 342,856 — — — 2,483 Issued — — — — — — — — Exercised — — — — — — — — Forfeited/Cancelled — — (3,319,999 ) — — — — — Outstanding, December 31, 2017 3,605,713 — — 342,856 — — — 2,483 Issued — — — — — — — — Exercised — — — — — — — — Forfeited/Cancelled — — — — — — — — Outstanding, December 31, 2018 3,605,713 — — 342,856 — — — 2,483 Common Stock Price per Warrant Weighted Jan 2013 Financing Marc 2013 Financing Total Warrants Range Average Exercise Price Outstanding, December 31, 2016 33,750 16,667 7,321,468 $ 1.75-30.00 $ 2.40 Issued — — — $ — — Exercised — — — $ — — Forfeited/Cancelled — — (3,319,999 ) $ 1.75 $ 1.75 Outstanding, December 31, 2017 33,750 16,667 4,001,469 $ 1.75-30.00 $ 2.94 Issued — — — $ — — Exercised — — — $ — — Forfeited/Cancelled (33,750 ) (16,667 ) (50,417 ) $ 30.00 $ 30.00 Outstanding, December 31, 2018 — — 3,951,052 $ 1.75 $ 1.75

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	10. Commitments and Contingencies Leases The Company has established its primary research facility in 8,215 square feet of leased office and laboratory space in Oceanside, California. The current lease for this facility expires in December 2021, with an option to terminate the lease on January 1, 2020 upon a six month advanced notice. The current base rent is approximately $10,000 per month. The facility has leasehold improvements which include cGMP (current Good Manufacturing Practices) level clean rooms designed for the derivation of clinical-grade stem cells and their differentiated derivatives, research laboratories for the Company’s stem cell differentiation studies and segregated rooms for biohazard control and containment of human donor tissue. The monthly base rent will increase by 3% annually on the anniversary date of the agreement. The Company leases a 13,320 square foot manufacturing facility in Frederick, Maryland, which is used for laboratory and administrative purposes. As of December 31, 2018, the base rent was approximately $17,000 per month. The lease was amended in October 2018 to increase the square footage from 8,280 square feet to 13,320 for an additional 5,040 square feet. In addition, the Company extended the lease to expire in November 2025. The administration space is used to support sales, marketing and accounting. The laboratory is being used to develop and manufacture the Company’s research products. The manufacturing laboratory space has clean rooms and is fitted with the necessary water purification systems, temperature controlled storage, labeling equipment and other standard manufacturing equipment to manufacture, package, test, store, and distribute cell culture products. On February 25, 2011, the Company entered into a lease agreement (the “Lease Agreement”) with S Real Estate Holdings LLC to allow the Company to expand into new corporate offices located at 5950 Priestly Drive, Carlsbad, California. The building is used for administrative purposes, but could also be used for research and development purposes if such space is needed in the future. The lease initially covered approximately 4,653 square feet, starting on March 1, 2011, and was amended to cover approximately 8,199 square feet effective July 1, 2011, and to cover approximately 9,848 square feet effective January 1, 2013. The lease expired on February 29, 2016, and the Company extended the term of the lease for one year. On February 22, 2017, the Company extended the term of the lease for an additional three years. The Company began paying rent at an initial rate of approximately $5,000 per month and the rate was amended effective July 1, 2011 and January 1, 2013 to account for additional square footage occupied by the Company. As of December 31, 2018, the base rent was approximately $13,000 per month. The monthly base rent will increase by 3% annually on the anniversary date of the agreement. The Company is also obligated to pay a portion of the utilities for the building and increases in property tax and insurance. S Real Estate Holdings LLC is owned by Dr. Russell Kern, the Company’s Executive Vice President and Chief Scientific Officer and a director, and was previously owned by Dr. Andrey Semechkin, the Company’s Chief Executive Officer and Co-Chairman of the Board of Directors. The Lease Agreement was negotiated at arm’s length and was reviewed by the Company’s outside legal counsel. The terms of the lease were reviewed by a committee of independent directors, and the Company believes that, in total, those terms are consistent with the terms that could be obtained for comparable facilities from an unaffiliated party. The Company incurred rent expense of $322,000 and $345,000 for the years ended December 31, 2018 and 2017, respectively. Future minimum lease payments required under operating leases that have initial or remaining non-cancelable lease terms in excess of one year as of December 31, 2018, are as follows (in thousands): Amount 2019 $ 491 2020 368 2021 347 2022 220 2023 227 Thereafter 454 Total $ 2,107 Customer Concentration During the year ended December 31, 2018 for the Biomedical market segment, one major customer accounted for approximately 33% and another customer accounted for 24% of consolidated revenues. During the year ended December 31, 2017 for the Biomedical market segment, one major customer accounted for 35% of consolidated revenues. No other single customer accounted for more than 10% of revenues for any period presented. Vendor Concentration During the year ended December 31, 2018, one vendor accounted for approximately 21% of consolidated purchases, while during the year ended December 31, 2017, no single vendor accounted for more than 10% of consolidated purchases.

Segments and Geographic Informa

Segments and Geographic Information	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Segments and Geographic Information	11. Segments and Geographic Information The Company’s chief operating decision-maker reviews financial information presented on a consolidated basis, accompanied by disaggregated information by each reporting segment’s statement of operations. The Company operates the business on the basis of three reporting segments, the parent company and two business units: International Stem Cell Corporation, incorporated in Delaware, is a research and development company, for the Therapeutic Market, which advances clinical applications of hpSCs for the treatment of various diseases of the central nervous system, liver diseases and is currently conducting clinical trials in Australia for the use of hpSCs in the treatment of Parkinson’s disease through its wholly-owned subsidiary, Cyto Therapeutics; Lifeline Skin Care, Inc. for the Cosmetic Market, which develops, manufactures and markets a category of cosmetic skin care products based on the Company’s proprietary parthenogenetic stem cell technology and targeted small molecule technology; Lifeline Cell Technology, LLC for the Biomedical Market, which develops, manufactures and commercializes primary human cell research products including approximately 200 human cell culture products, including frozen human “primary” cells and the reagents (called “media”) needed to grow, maintain and differentiate the cells. Revenues, Expenses and Operating Income (loss) The Company does not measure the performance of its segments on any asset-based metrics. Therefore, segment information is presented only for operating income (loss). Revenues, expenses and operating income (loss) by market segment were as follows (in thousands): Years Ended December 31, 2018 2017 Revenues: Cosmetic market $ 1,812 $ 2,256 Biomedical market 9,277 5,200 Total revenues 11,089 7,456 Expenses: Therapeutic market 5,904 6,391 Cosmetic market 2,637 2,634 Biomedical market 6,022 3,373 Total operating expenses 14,563 12,398 Operating income (loss): Therapeutic market (5,904 ) (6,391 ) Cosmetic market (825 ) (378 ) Biomedical market 3,255 1,827 Total loss from operations $ (3,474 ) $ (4,942 ) Geographic Information The Company’s wholly-owned subsidiaries are located in Maryland, California and Melbourne, Australia, and have customer and vendor relationships worldwide. Significant revenues in the following regions are those that are attributable to the individual country within the region to which the product was shipped (in thousands): Years Ended December 31, 2018 2017 North America $ 10,160 $ 6,347 Asia 612 728 Europe 293 354 All other regions 24 27 Total $ 11,089 $ 7,456

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	12. Subsequent Events On January 21, 2019, the Company entered into a Note Conversion Agreement with Dr. Andrey Semechkin, the Company’s Co-Chairman and Chief Executive Officer (the “Conversion Agreement”). The Conversion Agreement provides for the conversion of a total of $1.0 million (representing $1,000,000 of principal and $49,000 of accrued interest, representing all accrued interest on the amount owed to Dr. Semechkin) under the promissory note issued to Dr. Semechkin on August 8, 2018 (the “Original Note”) into a total of 599,222 shares of the Company’s common stock, representing a conversion price of $1.75 per share. Under the Conversion Agreement, the remaining $1,000,000 owed to Dr. Semechkin under the Original Note has been reflected in a new unsecured, non-convertible promissory note in the principal amount of $1,000,000 (the “New Note”). The outstanding principal amount under the New Note accrues interest at a rate of four and one-half percent (4.5%) per annum. The New Note is due and payable on January 15, 2020, but may be pre-paid by the Company without penalty at any time. On February 28, 2019, the Company granted approximately 1.1 million of stock options to certain employees at an exercise price of $1.51 with 3/36th options vesting on May 28, 2019 and the remaining options in equal monthly installments over a period of 33 months.

Organization and Significant _2

Organization and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Business Combination and Corporate Restructure	Business Combination and Corporate Restructure BTHC III, Inc. (“BTHC III” or the “Company”) was organized in Delaware in June 2005 as a shell company to effect the reincorporation of BTHC III, LLC, a Texas limited liability company. On December 28, 2006, the Company effected a Share Exchange pursuant to which it acquired all of the stock of International Stem Cell Corporation, a California corporation (“ISC California”). After giving effect to the Share Exchange, the stockholders of ISC California owned 93.7% of issued and outstanding shares of common stock. As a result of the Share Exchange, ISC California is now the wholly-owned subsidiary, though for accounting purposes it was deemed to have been the acquirer in a “reverse merger.” In the reverse merger, BTHC III is considered the legal acquirer and ISC California is considered the accounting acquirer. On January 29, 2007, the Company changed its name from BTHC III, Inc. to International Stem Cell Corporation. Lifeline Cell Technology, LLC (“LCT”) was formed in the State of California on August 17, 2001. LCT is in the business of developing and manufacturing purified primary human cells and optimized reagents for cell culture. LCT’s scientists have used a technology, called basal medium optimization, to systematically produce products designed to culture specific human cell types and to elicit specific cellular behaviors. These techniques also produce products that do not contain non-human animal proteins, a feature desirable to the research and therapeutic markets. LCT distinguishes itself in the industry by having in place scientific and manufacturing staff with the experience and knowledge to set up systems and facilities to produce a source of consistent, standardized, non-human animal protein free cell products, some of which are suitable for FDA approval. On July 1, 2006, LCT entered into an agreement among LCT, ISC California and the holders of membership units and warrants. Pursuant to the terms of the agreement, all the membership units in LCT were exchanged for 133,334 shares of ISC California Common Stock and for ISC California’s assumption of LCT’s obligations under the warrants. LCT became a wholly-owned subsidiary of ISC California. Lifeline Skin Care, Inc. (“LSC”) was formed in the State of California on June 5, 2009 and is a wholly-owned subsidiary of ISC California. LSC develops, manufactures and markets cosmetic products, utilizing an extract derived from the Company’s human parthenogenetic stem cell and the Company’s proprietary targeted small molecule technology. Cyto Therapeutics Pty. Ltd. (“Cyto Therapeutics”) was registered in the state of Victoria, Australia, on December 19, 2014 and is a limited proprietary company and a wholly-owned subsidiary of the Company. Cyto Therapeutics is a research and development company for the Therapeutic Market, which is conducting clinical trials in Australia for the use of human parthenogenetic stem cell (hpSCs) in the treatment of Parkinson’s disease.
Going Concern	Going Concern The Company has sustained recurring losses and needs to raise additional working capital. The timing and degree of any future capital requirements will depend on many factors. Currently, the Company’s burn rate is approximately $90,000 per month, excluding capital expenditures and patent costs averaging $55,000 per month. There can be no assurance that the Company will be successful in maintaining its normal operating cash flow and raising additional funds, and that such cash flows will be sufficient to sustain the Company’s operations through at least one year from the date the financial statements are available to be issued. Based on the above, there is substantial doubt about the Company’s ability to continue as a going concern. The consolidated financial statements were prepared assuming that the Company will continue as a going concern. The consolidated financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classification of liabilities that may result from the outcome of this uncertainty. Management’s plans in regard to these matters are focused on managing its cash flow, the proper timing of its capital expenditures, and raising additional capital or financing in the future.
Basis of Presentation	Basis of Presentation The Company is a biotechnology company focused on therapeutic and clinical product development with multiple long-term therapeutic opportunities and two revenue-generating subsidiaries with potential for increased future revenues. The Company has generated product revenues from the two commercial businesses of $11,089,000 and $7,456,000 for the years ended December 31, 2018 and 2017, respectively. The Company currently has no revenue generated from its principal operations in therapeutic and clinical product development through research and development efforts.
Principles of Consolidation	Principles of Consolidation The Company’s consolidated financial statements include the accounts of International Stem Cell Corporation and its subsidiaries after intercompany balances and transactions have been eliminated.
Cash Equivalents	Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less when purchased to be cash equivalents. There were no cash equivalents as of December 31, 2018 and 2017.
Inventory	Inventory Inventory is accounted for using the average cost and first-in, first-out (FIFO) methods for Lifeline Cell Technology (LCT) cell culture media and reagents, average cost and specific identification methods for Lifeline Skin Care (LSC) products, and specific identification method for LCT products. Inventory balances are stated at the lower of cost or net realizable value. Laboratory supplies used in the research and development process are expensed as consumed. Inventory is reviewed periodically for product expiration and obsolescence and is adjusted accordingly. The value of the inventory that is not expected to be sold within twelve months of the year end is classified as non-current inventory on the consolidated balance sheets.
Accounts Receivable	Accounts Receivable Trade accounts receivable are recorded at the net invoice value and are not interest bearing. Accounts receivable primarily consist of trade accounts receivable from the sales of LCT’s products, timing of cash receipts by the Company related to LSC credit card sales to customers, as well as LSC trade receivable amounts related to spa and distributor sales. The Company considers receivables past due based on the contractual payment terms. The Company reviews its exposure to accounts receivable and reserves specific amounts if collectability is no longer reasonably assured. As of December 31, 2018 and 2017, the Company had an allowance for doubtful accounts totaling $12,000.
Property and Equipment	Property and Equipment Property and equipment are stated at cost. The provision for depreciation and amortization is computed using the straight-line method over the estimated useful lives of the assets, generally over three to five years. The costs of major remodeling and leasehold improvements are capitalized and amortized over the shorter of the remaining term of the lease or the estimated life of the asset.
Intangible Assets	Intangible Assets Intangible assets consist of acquired research and development rights used in research and development, and capitalized legal fees related to the acquisition, filing, maintenance, and defense of patents and trademarks. Patent or patent license amortization only begins once a patent license is acquired or a patent is issued by the appropriate authoritative bodies. In the period in which a patent application is rejected or efforts to pursue the patent are abandoned, all the related accumulated costs are expensed. Patents and other intangible assets are recorded at cost of $3,632,000 and $3,763,000 at December 31, 2018 and 2017, respectively, and are amortized on a straight-line basis over the shorter of the lives of the underlying patents or the estimated useful life of the license. Amortization expense for the years ended December 31, 2018 and 2017 amounted to $117,000 and $139,000, respectively, and is included in research and development expense. Accumulated amortization as of December 31, 2018 and 2017 was $958,000 and $841,000, respectively. Additional information regarding patents and patent licenses is included in Note 4. The Company recognized $607,000 and $1.2 million of impairment losses on its intangible assets during the years ended December 31, 2018 and 2017, respectively, due to abandonment of efforts to pursue certain patents or patented technologies.
Long-Lived Asset Impairment	Long-Lived Asset Impairment The Company reviews long-lived assets for impairment when events or changes in business conditions indicate that their carrying value may not be recovered, and at least annually. The Company considers assets to be impaired and writes them down to estimated fair value if expected associated undiscounted cash flows are less than the carrying amounts. Fair value is the present value of the associated cash flows.
Revenue Recognition	Revenue Recognition Pursuant to the issuance by the Financial Accounting Standards Board (“FASB”) of Accounting Standards Codification (“ASC”), Revenue Recognition 1. Identify the contract with the customer 2. Identify the performance obligations in the contract 3. Determine the transaction price 4. Allocate the transaction price to the performance obligations in the contract 5. Recognize revenue when (or as) each performance obligation is satisfied Under ASC 606, the Company recognizes revenue when it satisfies a performance obligation by transferring control of the promised goods or services to its customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. The following table presents the Company’s revenue disaggregated by segment, product and geography, based on management’s assessment of available data (in thousands): Biomedical Market: Year Ended December 31, 2018 U.S. OUS* Total Revenues % of Total Revenues Biomedical products Cells $ 1,002 $ 405 $ 1,407 15 % Media 7,336 516 7,852 85 % Other 18 — 18 0 % Total $ 8,356 $ 921 $ 9,277 100 % *Outside the United States Year Ended December 31, 2017 U.S. OUS* Total Revenues % of Total Revenues Biomedical products Cells $ 1,181 $ 510 $ 1,691 33 % Media 2,967 533 3,500 67 % Other 9 — 9 0 % Total $ 4,157 $ 1,043 $ 5,200 100 % *Outside the United States Cosmetic Market: Year Ended December 31, 2018 Year Ended December 31, 2017 Total Revenues % of Total Revenues Total Revenues % of Total Revenues Cosmetic sales channels ecommerce $ 976 54 % $ 1,098 49 % Professional 836 46 % 1,153 51 % International — 0 % 5 0 % Total $ 1,812 100 % $ 2,256 100 % The Company's revenue consists primarily of sales of products from its two revenue-generating operating segments, the cosmetics products and biomedical products business segments. The cosmetic market segment markets and sells a line of luxury skincare products sold through three sales channels: ecommerce, professional, and international. The ecommerce channel sells direct to customers through online orders, while the professional sales are to spas, salons and other skincare providers. International sales are primarily through distributors. The biomedical market segment markets and sells primary human cell research products with two product categories, cells and media, both sold within and outside the United States. Contract terms for unit price, quantity, shipping and payment are governed by sales agreements, invoices or online order forms which the Company considers to be a customer's contract in all cases. The unit price is considered the observable stand-alone selling price for the arrangements. Any promotional or volume sales discounts are applied evenly to the units sold for purposes of calculating standalone selling price. Product sales generally consist of a single performance obligation that the Company satisfies at a point in time. The Company recognizes product revenue when the following events have occurred: (a) the Company has transferred physical possession of the products, (b) the Company has a present right to payment, (c) the customer has legal title to the products, and (d) the customer bears significant risks and rewards of ownership of the products. For LSC products, ecommerce sales are primarily paid through credit card charges, while professional and international sales are invoiced. The professional sales and biomedical products' standard payment terms for its customers are generally 30 days after the Company satisfies the performance obligations. For cosmetic products, the Company honors a 30-days return policy, but historical returns have been minimal and as such, the estimated allowance for sales returns was none and $10,000 as of December 31, 2018 and December 31, 2017 respectively. The Company elects to account for shipping and handling as activities to fulfill the promise to transfer the goods. As a result, no consideration is allocated to shipping and handling. Rather, the Company accrues the cost of shipping and handling upon shipment of the product, and all contract revenue is recognized at the same time. Variable Consideration The Company records revenue from customers in an amount that reflects the transaction price it expects to be entitled to after transferring control of those goods or services. From time to time, the Company offers sales promotions on its skincare products such as discounts and free product offers. Variable consideration is estimated at contract inception only to the extent that it is probable that a significant reversal of revenue will not occur and updated at the end of each reporting period as additional information becomes available. Contract Balances The Company records a receivable when it has an unconditional right to receive consideration after the performance obligations are satisfied. As of December 31, 2018 and December 31, 2017, accounts receivable, net, totaled $651,000 and $465,000, respectively. For the year ended December 31, 2018, the Company did not incur material impairment losses with respect to its receivables. Practical Expedients The Company has elected the practical expedient not to determine whether contracts with customers contain significant financing components. The Company pays commissions on certain sales for its biomedical and cosmetic market(s) once the customer payment has been received, which are accrued at the time of the sale. The Company generally expenses sales commissions when incurred because the amortization period would have been one year or less. These costs are recorded within sales and marketing expenses. In addition, the Company has elected to exclude sales taxes in consideration of the transaction price.
Allowance for Sales Returns	Allowance for Sales Returns The Company’s cosmetic products have a 30-day product return guarantee and based on historical rate of returns from the years ended December 31, 2015 through 2017, the Company determined that there is a low probability that returns will occur. The returns that have historically occurred have not been significant and have been recognized as they occur as a reduction of revenue that is recognized as performance obligations are met. As of December 31, 2018, the Company has no allowance for sales returns compared to the prior year of $10,000.
Cost of Sales	Cost of Sales Cost of sales consists primarily of salaries and benefits associated with employee efforts expended directly on the production of the Company’s products and include related direct materials, general laboratory supplies and allocation of overhead. Certain of the agreements under which the Company has licensed technology will require the payment of royalties based on the sale of its future products. Such royalties will be recorded as a component of cost of sales. Additionally, the amortization of license fees or milestone payments related to developed technologies used in the Company’s products will be classified as a component of cost of sales to the extent such payments become due in the future.
Research and Development Costs	Research and Development Costs Research and development costs, which are expensed as incurred, are primarily comprised of costs and expenses for salaries and benefits associated with research and development personnel, overhead and occupancy, contract services, and amortization of license costs for technology used in research and development with alternative future uses.
Stock-Based Compensation	Stock-Based Compensation The Company recognized stock-based compensation expense associated with stock options and other stock-based awards in accordance with the authoritative guidance for stock-based compensation. The cost of a stock-based award is measured at the grant date based on the estimated fair value of the award, and is recognized as expense on a straight-line basis, net of estimated forfeitures over the requisite service period of the award. The fair value of stock options is estimated using the Black-Scholes option valuation model, which requires the input of subjective assumptions, including price volatility of the underlying stock, risk-free interest rate, dividend yield, and expected life of the option. The fair value of restricted stock awards is based on the market value of the Company’s common stock on the date of grant.
Fair Value Measurements	Fair Value Measurements Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Assets and liabilities that are measured at fair value are reported using a three-level fair value hierarchy that prioritizes the inputs used to measure fair value. This hierarchy maximizes the use of observable inputs and minimizes the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: Level 1 Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities; Level 2 Quoted prices in markets that are not active, or inputs that are observable, either directly or indirectly, for substantially the full term of the asset or liability; and Level 3 Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (supported by little or no market activity). Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The table below sets forth a summary of the Company’s liabilities which are measured at fair value on a recurring basis as of December 31, 2018 (in thousands). Total Level 1 Level 2 Level 3 LIABILITIES: Warrants to purchase common stock $ 1,745 $ — $ — $ 1,745 The table below sets forth a summary of the Company’s liabilities which are measured at fair value on a recurring basis as of December 31, 2017 (in thousands). Total Level 1 Level 2 Level 3 LIABILITIES: Warrants to purchase common stock $ 3,113 $ — $ — $ 3,113 The following table displays the rollforward activity of liabilities with inputs that are both significant to the fair value measurement and unobservable (supported by little or no market activity) (in thousands): Warrants common stock Beginning balance at December 31, 2016 $ 2,045 Adjustments to estimated fair value 1,068 Ending balance at December 31, 2017 3,113 Adjustments to estimated fair value (1,368 ) Ending balance at December 31, 2018 $ 1,745
Income Taxes	Income Taxes The Company accounts for income taxes in accordance with applicable authoritative guidance, which requires the Company to provide a net deferred tax asset/liability equal to the expected future tax benefit/expense of temporary reporting differences between book and tax accounting methods and any available operating loss or tax credit carryforwards.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements. Significant estimates include patent life (remaining legal life versus remaining useful life), inventory carrying values, allowance for excess and obsolete inventories, allowance for sales returns and doubtful accounts, and transactions using the Black-Scholes option pricing model, e.g., warrants and stock options, as well as the Monte-Carlo valuation method for certain warrants. Actual results could differ from those estimates.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company believes that the carrying value of its cash and cash equivalents, receivables, accounts payable, accrued liabilities, and related party payable as of December 31, 2018 and 2017 approximate their fair values because of the short-term nature of those instruments. The fair value of certain warrants was determined at each issuance and reporting date and other applicable re-measurement dates in 2018 and 2017 using the Monte-Carlo valuation methodology.
Income (Loss) Per Common Share	Income (Loss) Per Common Share The computation of net loss per common share is based on the weighted average number of shares outstanding during each period. The computation of diluted earnings per common share is based on the weighted average number of shares outstanding during the period plus the common stock equivalents, which would arise from the exercise of stock options and warrants outstanding using the treasury stock method and the average market price per share during the period. At December 31, 2018, there were 1,824,885 vested and 2,542,457 non-vested stock options outstanding and 3,951,052 warrants outstanding; and at December 31, 2017, there were 4,001,469 warrants, and 1,011,590 vested and 1,284,489 non-vested stock options outstanding. These stock options, warrants, and convertible preferred stock were not included in the diluted loss per share calculation because the effect would have been anti-dilutive. Refer to Note 6 for convertible preferred stock.
Comprehensive Income	Comprehensive Income Comprehensive income or loss includes all changes in stockholders’ equity except those resulting from investments by owners and distributions to owners. The Company did not have any items of comprehensive income or loss other than net loss from operations for the years ended December 31, 2018 and 2017.
Recent Accounting Pronouncements	Recent Accounting Pronouncements I n August 2018, the FASB issued Accounting Standards Update (“ASU”) 2018-13, “Fair Value Measurement (Topic 820), “Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement” (“ASU 2018-13), which removes the valuation processes for Level 3 fair value measurements and adds the disclosure for the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. The updated standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The Company is currently evaluating the impact of the adoption of this accounting standard update. In June 2018, the FASB issued ASU 2018-07, “Compensation – Stock Compensation (Topic 718), Improvements to Nonemployee Share-Based Payment Accounting.” I n July 2017, the FASB issued ASU 2017-11, “Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), and Derivatives and Hedging (Topic 815 ). ASU 2017-11 changes the classification analysis of certain equity-linked financial instruments (or embedded features) with down round features and requires entities that present earnings per share (“EPS”) in accordance with Topic 260 to recognize the effect of the down round feature when triggered with the effect treated as a dividend and as a reduction of income available to common shareholders in basic EPS. The updated standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. In February 2016, the FASB issued ASU No. 2016-02, Leases

Organization and Significant _3

Organization and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Revenue Disaggregated by Segment, Product and Geography Based on Management's Assessment	The following table presents the Company’s revenue disaggregated by segment, product and geography, based on management’s assessment of available data (in thousands): Biomedical Market: Year Ended December 31, 2018 U.S. OUS* Total Revenues % of Total Revenues Biomedical products Cells $ 1,002 $ 405 $ 1,407 15 % Media 7,336 516 7,852 85 % Other 18 — 18 0 % Total $ 8,356 $ 921 $ 9,277 100 % *Outside the United States Year Ended December 31, 2017 U.S. OUS* Total Revenues % of Total Revenues Biomedical products Cells $ 1,181 $ 510 $ 1,691 33 % Media 2,967 533 3,500 67 % Other 9 — 9 0 % Total $ 4,157 $ 1,043 $ 5,200 100 % *Outside the United States Cosmetic Market: Year Ended December 31, 2018 Year Ended December 31, 2017 Total Revenues % of Total Revenues Total Revenues % of Total Revenues Cosmetic sales channels ecommerce $ 976 54 % $ 1,098 49 % Professional 836 46 % 1,153 51 % International — 0 % 5 0 % Total $ 1,812 100 % $ 2,256 100 %
Fair Values of Liabilities on a Recurring Basis	The table below sets forth a summary of the Company’s liabilities which are measured at fair value on a recurring basis as of December 31, 2018 (in thousands). Total Level 1 Level 2 Level 3 LIABILITIES: Warrants to purchase common stock $ 1,745 $ — $ — $ 1,745 The table below sets forth a summary of the Company’s liabilities which are measured at fair value on a recurring basis as of December 31, 2017 (in thousands). Total Level 1 Level 2 Level 3 LIABILITIES: Warrants to purchase common stock $ 3,113 $ — $ — $ 3,113
Fair Value Measurement and Unobservable Rollforward Activity of Liabilities	The following table displays the rollforward activity of liabilities with inputs that are both significant to the fair value measurement and unobservable (supported by little or no market activity) (in thousands): Warrants common stock Beginning balance at December 31, 2016 $ 2,045 Adjustments to estimated fair value 1,068 Ending balance at December 31, 2017 3,113 Adjustments to estimated fair value (1,368 ) Ending balance at December 31, 2018 $ 1,745

Inventory (Tables)

Inventory (Tables)	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Summary of the Components of Inventories	The components of inventories are as follows (in thousands): December 31, December 31, 2018 2017 Raw materials $ 656 $ 609 Work in process 590 472 Finished goods 1,276 1,154 Total 2,522 2,235 Less: allowance for inventory excess and obsolescence (216 ) (236 ) Inventory, net $ 2,306 $ 1,999

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property Plant And Equipment [Abstract]
Summary of Property and Equipment	Property and equipment consists of the following (in thousands): December 31, December 31, 2018 2017 Machinery and equipment $ 1,614 $ 1,459 Computer equipment 251 429 Office equipment 215 214 Leasehold improvements 996 805 Construction in progress 45 — 3,121 2,907 Less: accumulated depreciation and amortization (2,652 ) (2,586 ) Property and equipment, net $ 469 $ 321

Patent Licenses (Tables)

Patent Licenses (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Future Amortization Expense Related to Intangible Assets Subject to Amortization	At December 31, 2018, future amortization expense related to the intangible assets subject to amortization is expected to be as follows (in thousands): Amount 2019 $ 96 2020 79 2021 79 2022 79 2023 79 Thereafter 2,179 Total $ 2,591

Advances (Tables)

Advances (Tables)	12 Months Ended
	Dec. 31, 2018
Advances [Abstract]
Schedule of Advances from Nonaffiliated Collaboration	As of December 31, 2018, no revenues were realized from this agreement. December 31, December 31, 2018 2017 BioTime, Inc. (in thousands) $ 250 $ 250

Capital Stock (Tables)

Capital Stock (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Summary of Shares of Common Stock Reserved for Future Issuance	At December 31, 2018, the Company had shares of common stock reserved for future issuance as follows: Options outstanding 4,367,342 Options available for future grant 5,082,901 Convertible preferred stock 6,120,725 Warrants 3,951,052 19,522,020

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Reconciliation of Statutory Federal Income Tax Rate and Effective Income Tax Rate	A reconciliation of the statutory Federal income tax rate and the effective income tax rate for the years ended December 31, 2018 and 2017 follows: December 31, December 31, 2018 2017 Statutory federal income tax rate 21 % 35 % Permanent items 6 % (11 )% State income taxes, net of federal taxes 4 % (7 )% Foreign (2 )% (3 )% Change in valuation allowance (27 )% 175 % Change in tax rates 0 (189 )% Tax credits claimed (1 )% 0 % Other (1 )% 0 % Effective income tax rate 0 % 0 %
Summary of Significant Components of Deferred Tax Assets and Liabilities	Significant components of deferred tax assets and liabilities are as follows (in thousands): December 31, December 31, 2018 2017 Net operating loss carryforwards $ 17,569 $ 16,842 Stock based compensation 2,437 2,695 Research and development tax credit 2,729 2,696 Other 260 192 Non-current deferred tax assets 22,995 22,425 Valuation allowances (22,995 ) (22,425 ) Net deferred tax assets $ — $ —
Summary of Components of Provision for Income Taxes	The components of the provision for income taxes were as follows: December 31, December 31, 2018 2017 Current $ — $ — Deferred — — Total $ — $ —

Stock Options and Warrants (Tab

Stock Options and Warrants (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Total Stock-based Compensation Expense	Total stock-based compensation expense for the years ended December 31, 2018 and 2017 was comprised of the following (in thousands): Years Ended December 31, 2018 2017 Cost of sales $ 57 $ 23 Research and development 641 637 Selling and marketing 54 41 General and administrative 929 683 $ 1,681 $ 1,384
Fair Value of Stock Option Award Weighted Average Assumptions	The fair value of options granted is estimated at the date of grant using a Black-Scholes option-pricing model with the following weighted-average assumptions for the years ended December 31, 2018 and 2017: Year Ended Year Ended December 31, December 31, 2018 2017 Significant assumptions (weighted average): Risk-free interest rate at grant date 2.72 % 1.95 % Expected stock price volatility 92.68 % 96.71 % Expected dividend payout 0 % 0 % Expected option life based on management's estimate 5.70 yrs 5.71 yrs
Summary of Changes in Options Outstanding and Related Exercise Prices	Additional information regarding options outstanding under our option plans as of December 31, 2018 is as follows: Options Outstanding Options Exercisable and Vested Weighted Average Weighted Average Remaining Remaining Number Contractual Life Weighted Average Number Contractual Life Weighted Average Exercise Prices Outstanding (Years) Exercise Price Exercisable (Years) Exercise Price $1.09-$1.49 667,059 8.28 $ 1.11 385,903 8.32 $ 1.12 $1.50-$1.55 996,944 9.20 $ 1.51 250,694 9.20 $ 1.51 $1.56-$1.59 1,354,389 9.62 $ 1.58 228,138 9.62 $ 1.58 $1.60-$3.03 452,594 8.22 $ 2.03 283,299 7.99 $ 2.09 $3.04-$289.50 883,722 6.91 $ 13.45 664,217 6.80 $ 16.65 4,354,708 8.62 $ 3.95 1,812,251 8.00 $ 7.08
Summary of Changes in Options Outstanding and Related Exercise Prices for Shares of Company's Common Stock Options Issued	The following table summarizes the changes in options outstanding and the related exercise prices for the Company’s common stock options issued: Number of Weighted Options Weighted Average Aggregate Under Average Remaining Intrinsic 2006 Plan and Price Per Contractual Value 2010 Plan Share Term (in thousands) Outstanding at December 31, 2016 1,460,076 $ 13.21 Granted 1,145,568 $ 1.14 Exercised — $ — Canceled or expired (360,295 ) $ 5.80 Outstanding at December 31, 2017 2,245,349 $ 8.25 Granted 2,568,842 $ 1.56 Exercised (140,968 ) $ 1.13 Canceled or expired (318,515 ) $ 16.21 Outstanding at December 31, 2018 4,354,708 $ 3.95 8.62 years $ 299 Vested and expected to vest at December 31, 2018 4,056,445 $ 4.12 8.58 years $ 290 Exercisable at December 31, 2018 1,812,251 $ 7.08 8.00 years $ 162 Weighted Number of Weighted Average Aggregate Options Issued Average Exercise Remaining Intrinsic Outside Price Per Contractual Value the Plan Share Term (in thousands) Outstanding, vested and exercisable at December 31, 2016 50,730 $ 92.31 Granted — $ — Exercised — $ — Canceled or expired — $ — Outstanding, vested and exercisable at December 31, 2017 50,730 $ 92.31 Granted — $ — Exercised — $ — Canceled or expired (38,096 ) $ 93.00 Outstanding, vested and exercisable at December 31, 2018 12,634 $ 90.23 0.90 years $ —
Summary of Changes in Restricted Stock Award Activity	The following table summarizes the changes in restricted stock award activity and related weighted average grant date fair values for the Company’s awards issued during the years ended December 31, 2018 and 2017: Restricted Stock Issued from the Weighted 2006 Average Grant Date 2010 Plan Fair Value Unvested at December 31, 2016 — $ — Granted 30,643 $ 1.60 Vested (30,643 ) $ 1.60 Forfeited — $ — Unvested at December 31, 2017 — $ — Granted 9,855 $ 1.55 Vested (9,855 ) $ 1.55 Forfeited — $ — Unvested at December 31, 2018 — $ —
Summary of Outstanding Warrants Related to Warrant Transactions	Share data related to warrant transactions for the years ended December 31, 2018 and 2017 were as follows: Common Stock Common Stock March 2016 Financing October 2014 Financing Series A Series B Series C Placement Agent Series A Series B Series C Placement Agent Outstanding, December 31, 2016 3,605,713 — 3,319,999 342,856 — — — 2,483 Issued — — — — — — — — Exercised — — — — — — — — Forfeited/Cancelled — — (3,319,999 ) — — — — — Outstanding, December 31, 2017 3,605,713 — — 342,856 — — — 2,483 Issued — — — — — — — — Exercised — — — — — — — — Forfeited/Cancelled — — — — — — — — Outstanding, December 31, 2018 3,605,713 — — 342,856 — — — 2,483 Common Stock Price per Warrant Weighted Jan 2013 Financing Marc 2013 Financing Total Warrants Range Average Exercise Price Outstanding, December 31, 2016 33,750 16,667 7,321,468 $ 1.75-30.00 $ 2.40 Issued — — — $ — — Exercised — — — $ — — Forfeited/Cancelled — — (3,319,999 ) $ 1.75 $ 1.75 Outstanding, December 31, 2017 33,750 16,667 4,001,469 $ 1.75-30.00 $ 2.94 Issued — — — $ — — Exercised — — — $ — — Forfeited/Cancelled (33,750 ) (16,667 ) (50,417 ) $ 30.00 $ 30.00 Outstanding, December 31, 2018 — — 3,951,052 $ 1.75 $ 1.75

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Summary of Future Minimum Lease Payments Required under Operating Leases that Have Initial or Remaining Non-Cancelable Lease Terms in Excess of One Year	Future minimum lease payments required under operating leases that have initial or remaining non-cancelable lease terms in excess of one year as of December 31, 2018, are as follows (in thousands): Amount 2019 $ 491 2020 368 2021 347 2022 220 2023 227 Thereafter 454 Total $ 2,107

Segments and Geographic Infor_2

Segments and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Revenues, Expenses and Operating Income (Loss) by Market Segment	Revenues, expenses and operating income (loss) by market segment were as follows (in thousands): Years Ended December 31, 2018 2017 Revenues: Cosmetic market $ 1,812 $ 2,256 Biomedical market 9,277 5,200 Total revenues 11,089 7,456 Expenses: Therapeutic market 5,904 6,391 Cosmetic market 2,637 2,634 Biomedical market 6,022 3,373 Total operating expenses 14,563 12,398 Operating income (loss): Therapeutic market (5,904 ) (6,391 ) Cosmetic market (825 ) (378 ) Biomedical market 3,255 1,827 Total loss from operations $ (3,474 ) $ (4,942 )
Summary of Significant Revenues in Following Regions	Significant revenues in the following regions are those that are attributable to the individual country within the region to which the product was shipped (in thousands): Years Ended December 31, 2018 2017 North America $ 10,160 $ 6,347 Asia 612 728 Europe 293 354 All other regions 24 27 Total $ 11,089 $ 7,456

Organization and Significant _4

Organization and Significant Accounting Policies - Additional Information (Detail)	Jul. 01, 2006shares	Dec. 31, 2018USD ($)SubsidiarySegmentshares	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)
Organization And Significant Accounting Policies [Line Items]
Percentage of ownership in issued and outstanding shares of common stock parent Company		93.70%
Common stock in subsidiary Company | shares	133,334
Burn rate		$ 90,000
Capital expenditures and patent costs		$ 55,000
Revenue-generating subsidiaries | Subsidiary		2
Revenues		$ 11,089,000	$ 7,456,000
Original maturities period, maximum		3 months
Cash equivalents		$ 0	0
Allowance for doubtful accounts receivable		12,000	12,000
Patents and other intangible assets		3,632,000	3,763,000
Accumulated amortization		958,000	841,000
Impairment losses on intangible assets		$ 607,000	1,200,000
Number of revenue-generating operating segments | Segment		2
Description of payment terms		The Company's revenue consists primarily of sales of products from its two revenue-generating operating segments, the cosmetics products and biomedical products business segments. The cosmetic market segment markets and sells a line of luxury skincare products sold through three sales channels: ecommerce, professional, and international. The ecommerce channel sells direct to customers through online orders, while the professional sales are to spas, salons and other skincare providers. International sales are primarily through distributors. The biomedical market segment markets and sells primary human cell research products with two product categories, cells and media, both sold within and outside the United States
Allowance for sales returns		$ 0
Accounts receivable, net		651,000	465,000
Impairment losses with respect to receivables		$ 0	0
Product return guarantee period		30 days
Decrease in allowance for sales return			$ 10,000	$ 10,000	$ 10,000
Vested stock options outstanding | shares		1,824,885	1,011,590
Stock options outstanding, non-vested | shares		2,542,457	1,284,489
Warrants outstanding | shares		3,951,052	4,001,469	7,321,468
LSC [Member]
Organization And Significant Accounting Policies [Line Items]
Allowance for sales returns		$ 0	$ 10,000
Research and Development [Member]
Organization And Significant Accounting Policies [Line Items]
Amortization expense		$ 117,000	$ 139,000
Minimum [Member]
Organization And Significant Accounting Policies [Line Items]
Estimated useful life of property and equipment		3 years
Maximum [Member]
Organization And Significant Accounting Policies [Line Items]
Estimated useful life of property and equipment		5 years
Sales commissions amortization period		1 year

Organization and Significant _5

Organization and Significant Accounting Policies - Summary of Revenue Disaggregated by Segment, Product and Geography Based on Management's Assessment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Total Revenues	$ 11,089	$ 7,456
Biomedical Market [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	$ 9,277	$ 5,200
% of Total Revenues	100.00%	100.00%
Biomedical Market [Member] | Cells [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	$ 1,407	$ 1,691
% of Total Revenues	15.00%	33.00%
Biomedical Market [Member] | Media [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	$ 7,852	$ 3,500
% of Total Revenues	85.00%	67.00%
Biomedical Market [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	$ 18	$ 9
% of Total Revenues	0.00%	0.00%
Cosmetic Market [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	$ 1,812	$ 2,256
% of Total Revenues	100.00%	100.00%
Cosmetic Market [Member] | Ecommerce [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	$ 976	$ 1,098
% of Total Revenues	54.00%	49.00%
Cosmetic Market [Member] | Professional [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	$ 836	$ 1,153
% of Total Revenues	46.00%	51.00%
Cosmetic Market [Member] | International [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues		$ 5
% of Total Revenues	0.00%	0.00%
U.S. [Member] | Biomedical Market [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	$ 8,356	$ 4,157
U.S. [Member] | Biomedical Market [Member] | Cells [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	1,002	1,181
U.S. [Member] | Biomedical Market [Member] | Media [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	7,336	2,967
U.S. [Member] | Biomedical Market [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	18	9
OUS [Member] | Biomedical Market [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	921	1,043
OUS [Member] | Biomedical Market [Member] | Cells [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	405	510
OUS [Member] | Biomedical Market [Member] | Media [Member]
Disaggregation Of Revenue [Line Items]
Total Revenues	$ 516	$ 533

Organization and Significant _6

Organization and Significant Accounting Policies - Fair Values of Liabilities on a Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - Warrants [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
LIABILITIES:
Warrants to purchase common stock	$ 1,745	$ 3,113
Level 3 [Member]
LIABILITIES:
Warrants to purchase common stock	$ 1,745	$ 3,113

Organization and Significant _7

Organization and Significant Accounting Policies - Fair Value Measurement and Unobservable Rollforward Activity of Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Adjustments to estimated fair value	$ 1,368	$ (1,068)
Warrants [Member]
Fair Value Disclosures [Abstract]
Beginning balance	3,113	2,045
Adjustments to estimated fair value	(1,368)	1,068
Ending balance	$ 1,745	$ 3,113

Inventory - Summary of the Comp

Inventory - Summary of the Components of Inventories (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 656	$ 609
Work in process	590	472
Finished goods	1,276	1,154
Total	2,522	2,235
Less: allowance for inventory excess and obsolescence	(216)	(236)
Inventory, net	$ 2,306	$ 1,999

Property and Equipment - Summar

Property and Equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 3,121	$ 2,907
Less: accumulated depreciation and amortization	(2,652)	(2,586)
Property and equipment, net	469	321
Machinery and Equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,614	1,459
Computer Equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	251	429
Office Equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	215	214
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	996	$ 805
Construction in Progress [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 45

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Depreciation and amortization expense	$ 191	$ 187

Patent Licenses - Additional In

Patent Licenses - Additional Information (Detail)	Feb. 07, 2013Installment	May 14, 2004USD ($)	Feb. 13, 2004USD ($)	Dec. 31, 2003USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Finite-Lived Intangible Assets [Line Items]
Other patent acquisition costs and trademarks					$ 2,885,000
UMass IP [Member]
Finite-Lived Intangible Assets [Line Items]
Obligation to pay royalties (Ranged)	0.25%
Minimum annual license fee							$ 150,000	$ 75,000
Number of installments | Installment	2
UMass IP [Member] | Minimum [Member] | Previously Reported [Member]
Finite-Lived Intangible Assets [Line Items]
Obligation to pay royalties (Ranged)	6.00%
UMass IP [Member] | Maximum [Member] | Previously Reported [Member]
Finite-Lived Intangible Assets [Line Items]
Obligation to pay royalties (Ranged)	12.00%
Astellas IP [Member]
Finite-Lived Intangible Assets [Line Items]
Patent acquisition costs					747,000
License [Member]
Finite-Lived Intangible Assets [Line Items]
Option and license fees		$ 400,000	$ 22,500	$ 340,000
License [Member] | UMass IP [Member]
Finite-Lived Intangible Assets [Line Items]
Option and license fees					$ 75,000	$ 75,000

Patent Licenses - Summary of Fu

Patent Licenses - Summary of Future Amortization Expense Related to Intangible Assets Subject to Amortization (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
2019	$ 96
2020	79
2021	79
2022	79
2023	79
Thereafter	2,179
Total	$ 2,591

Advances - Additional Informati

Advances - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Jun. 18, 2008
Advances [Abstract]
Advances from nonaffiliated collaboration	$ 250,000	$ 250,000	$ 250,000
Specified amount of revenue to be utilized for advances			$ 250,000
Revenue realized from agreement	$ 0

Advances - Schedule of Advances

Advances - Schedule of Advances from Nonaffiliated Collaboration (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Jun. 18, 2008
Advances [Abstract]
Advances from nonaffiliated collaboration	$ 250	$ 250	$ 250

Capital Stock - Additional Info

Capital Stock - Additional Information (Detail) - USD ($)	Oct. 02, 2018	Sep. 21, 2018	Mar. 12, 2013	Jan. 22, 2013	Dec. 31, 2018	Dec. 31, 2017
Equity [Abstract]
Common stock, shares authorized					120,000,000	120,000,000
Preferred stock, shares authorized					20,000,000
Common stock, par value					$ 0.001	$ 0.001
Preferred stock, par value					$ 0.001
Sale of shares to accredited investor			33,334	67,500
Gain recognized on trade payables settlement under other income					$ 32,000
Common Stock [Member]
Equity [Abstract]
Sale of shares to accredited investor					286,000	286,000
Shares issued in satisfaction of owed to creditior	160,192
Issuance price per share	$ 1.75
Amount of shares issued in satisfaction of owed to creditior	$ 280,000
Gain recognized on trade payables settlement under other income	$ 32,000
September 2018 Private Placement [Member] | Common Stock [Member]
Equity [Abstract]
Sale of shares to accredited investor		285,714
Aggregate purchase price for sale of shares to accredited investor		$ 500,000
Sale of share price per share		$ 1.75

Capital Stock - Series B Prefer

Capital Stock - Series B Preferred Stock Transactions - Additional Information (Detail) $ / shares in Units, $ in Thousands	May 12, 2008USD ($)Investor$ / sharesshares	Mar. 31, 2016$ / shares	May 31, 2008	Dec. 31, 2018$ / sharesshares	Oct. 02, 2018$ / shares	Dec. 31, 2017shares	Dec. 31, 2016$ / shares	Mar. 12, 2013$ / shares	Jan. 22, 2013$ / shares
Class of Stock [Line Items]
Number of accredited investors | Investor	5
Warrants exercisable price				$ 1.75				$ 30	$ 30
Restricted Stock [Member]
Class of Stock [Line Items]
Shares issued to non-employee directors							$ 1.08
Series B Warrants [Member]
Class of Stock [Line Items]
Number of warrants to purchase common stock | shares	2
Common Stock [Member]
Class of Stock [Line Items]
Shares issued to non-employee directors					$ 1.75
Series B Preferred Stock [Member]
Class of Stock [Line Items]
Number of units issued | shares	400,000
Number of Series B Preferred Stock for each Series B unit | shares	1
Common stock purchase price, per share	$ 1
Proceeds from issuance of preferred stock and warrants | $	$ 400
Initial conversion price	$ 75
Warrants exercisable price	$ 75
Number of years from issuance of warrants to convert as common stock	5 years
Liquidation premium			6.00%
Preferred stock, shares issued | shares				250,000		250,000
Preferred stock, shares outstanding | shares				250,000		250,000
Convertible preferred stock, conversion price		$ 1.08
Series B Preferred Stock [Member] | Common Stock [Member]
Class of Stock [Line Items]
Conversion ratio for each share | shares	0.0134

Capital Stock - Series D Prefer

Capital Stock - Series D Preferred Stock Transactions - Additional Information (Detail) - $ / shares	Mar. 12, 2013	Jan. 22, 2013	Dec. 30, 2008	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Number of shares of common stock sold	33,334	67,500
Series D Preferred Stock [Member]
Class of Stock [Line Items]
Number of shares of common stock sold			43
Preferred stock, price per share			$ 100,000
Preferred stock, shares issued					43	43
Preferred stock, shares outstanding					43	43
Initial conversion price			$ 37.50
Conversion ratio for each share			2,667
Convertible preferred stock, conversion price				$ 1.75
Series D Preferred Stock [Member] | X-Master Inc. [Member]
Class of Stock [Line Items]
Number of shares of common stock sold			10
Series D Preferred Stock [Member] | Co-Chairman and Chief Executive Officer [Member]
Class of Stock [Line Items]
Number of shares of common stock sold			33
Series I Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares outstanding					5,124	5,614
Initial conversion price				$ 1.75	$ 1.75

Capital Stock - Series G Prefer

Capital Stock - Series G Preferred Stock Transactions - Additional Information (Detail)	Oct. 02, 2018USD ($)$ / sharesshares	Mar. 12, 2013shares	Jan. 22, 2013shares	Mar. 09, 2012USD ($)Directors$ / sharesshares	Dec. 31, 2018$ / sharesshares	Dec. 31, 2017shares
Class of Stock [Line Items]
Number of shares of common stock sold		33,334	67,500
Common Stock [Member]
Class of Stock [Line Items]
Number of shares of common stock sold					286,000	286,000
Issuance price per share | $ / shares	$ 1.75
Shares issued in satisfaction of owed to creditior	160,192
Amount of shares issued in satisfaction of owed to creditior | $	$ 280,000
Series G Preferred Stock [Member]
Class of Stock [Line Items]
Convertible preferred stock, conversion price | $ / shares				$ 60	$ 9.92
Conversion ratio for each share				0.0167	0.10
Number of directors to be nominated by preferred shareholders | Directors				2
Number of independent directors out of directors to be nominated by preferred shareholders | Directors				1
Preferred stock, shares issued					5,000,000	5,000,000
Preferred stock, shares outstanding					5,000,000	5,000,000
Series G Preferred Stock [Member] | Minimum [Member]
Class of Stock [Line Items]
Convertible Redeemable Preferred stock, shares outstanding				1,000,000
Series G Preferred Stock [Member] | AR Partners, LLC [Member]
Class of Stock [Line Items]
Number of shares of common stock sold				5,000,000
Issuance price per share | $ / shares				$ 1
Total proceeds | $				$ 5,000,000

Capital Stock - Series I Prefer

Capital Stock - Series I Preferred Stock Transactions - Additional Information (Detail) - USD ($)	Mar. 15, 2016	Mar. 09, 2016	Mar. 12, 2013	Jan. 22, 2013	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Number of shares of convertible preferred stock sold			33,334	67,500
Warrants outstanding converted into common stock			16,667	33,750
Warrants exercisable price			$ 30	$ 30		$ 1.75
Warrant term				5 years
Common Stock [Member]
Class of Stock [Line Items]
Number of shares of convertible preferred stock sold						286,000	286,000
Conversion of preferred stock, shares						280,000	215,000
Placement Agent [Member]
Class of Stock [Line Items]
Warrants exercisable price		$ 3.64
Warrant term		5 years
Date of placement agency engagement letter		Mar. 9, 2016
Placement agent fee		$ 200,000
From exercises of warrants, shares		343,000
Reimbursement of fees and expenses		$ 50,000
Series I-1 Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares outstanding						814	1,304
Series I-2 Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares outstanding						4,310	4,310
Series I Preferred Stock [Member]
Class of Stock [Line Items]
Initial conversion price					$ 1.75	$ 1.75
Conversion of stock, shares converted						490	376
Preferred stock, shares outstanding						5,124	5,614
Series I Preferred Stock [Member] | Common Stock [Member]
Class of Stock [Line Items]
Conversion of preferred stock, shares						280,000	214,700
Purchasers [Member] | Securities Purchase Agreement [Member] | Chief Executive Officer and Co-Chairman [Member]
Class of Stock [Line Items]
Cash proceeds	$ 2,500,000
Purchasers [Member] | Securities Purchase Agreement [Member] | Series A Warrants [Member] | Chief Executive Officer and Co-Chairman [Member]
Class of Stock [Line Items]
Warrants outstanding converted into common stock		3,600,000
Warrants exercisable price		$ 3.64
Warrant term		5 years
Purchasers [Member] | Securities Purchase Agreement [Member] | Series B Warrants [Member] | Chief Executive Officer and Co-Chairman [Member]
Class of Stock [Line Items]
Warrants outstanding converted into common stock		3,600,000
Warrants exercisable price		$ 1.75
Warrant term		6 months
Purchasers [Member] | Securities Purchase Agreement [Member] | Series C Warrants [Member] | Chief Executive Officer and Co-Chairman [Member]
Class of Stock [Line Items]
Warrants outstanding converted into common stock		3,600,000
Warrants exercisable price		$ 1.75
Warrant term		12 months
Purchasers [Member] | Securities Purchase Agreement [Member] | Series I-1 Preferred Stock [Member] | Chief Executive Officer and Co-Chairman [Member]
Class of Stock [Line Items]
Number of shares of convertible preferred stock sold		2,000
Preferred stock, stated value per share		$ 1,000
Purchasers [Member] | Securities Purchase Agreement [Member] | Series I-2 Preferred Stock [Member] | Chief Executive Officer and Co-Chairman [Member]
Class of Stock [Line Items]
Number of shares of convertible preferred stock sold		4,310
Preferred stock, stated value per share		$ 1,000

Capital Stock - Summary of Shar

Capital Stock - Summary of Shares of Common Stock Reserved for Future Issuance (Detail)	Dec. 31, 2018shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for future issuance net	19,522,020
Options Outstanding [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for future issuance net	4,367,342
Options Available for Future Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for future issuance net	5,082,901
Convertible Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for future issuance net	6,120,725
Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for future issuance net	3,951,052

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	Dec. 07, 2017	Aug. 08, 2018	Sep. 01, 2017	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Related party rent expense				$ 160,000	$ 154,000
Related party payable				2,045,000
Accrued and unpaid interest on promissory note				45,000
Non-convertible promissory note, principal amount				$ 2,000,000
Unsecured Non-convertible Promissory Note [Member] | Chief Executive Officer and Co-Chairman [Member]
Related Party Transaction [Line Items]
Maturity date		Nov. 1, 2018
Annual interest rate		4.00%
Related party transaction, description				The outstanding principal amount under the Note accrued interest at a rate of four percent (4%) per annum. The Note was due and payable November 1, 2018 and on November 12, 2018, to satisfy the indebtedness incurred on the Note, an amendment to the Note was entered into extending the due date to January 15, 2019
Non-convertible promissory note, principal amount		$ 2,000,000
Common Stock [Member]
Related Party Transaction [Line Items]
Promissory note converted to shares					1,575,000
Co-Chairman and Chief Executive Officer [Member]
Related Party Transaction [Line Items]
Related party payable			$ 2,700,000
Maturity date			Sep. 1, 2017
Annual interest rate			3.50%
Related party transaction, description				On December 7, 2017, to obtain funding for working capital purposes and to satisfy the indebtedness incurred on September 1, 2017, the Company entered into a Note Conversion and Stock Purchase Agreement (the “Agreement”) with Dr. Andrey Semechkin. Pursuant to the Agreement, the Company agreed to issue Dr. Semechkin a total of 1,860,810 shares of Common Stock at a conversion price and a purchase price of $1.75 per share in return for cancellation and surrender of the note issued to him by the Company on September 1, 2017 with a principal amount of $2,700,000 and all accrued and unpaid interest on the note of $56,000 and payment of an additional $500,000 by Dr. Semechkin to the Company.
Co-Chairman and Chief Executive Officer [Member] | Note Conversion and Stock Purchase Agreement [Member]
Related Party Transaction [Line Items]
Debt cancelled and surrendered	$ 2,700,000
Related party transaction agreement date				Dec. 7, 2017
Conversion price and purchase price	$ 1.75
Accrued and unpaid interest on promissory note	$ 56,000
Payment received from related party	$ 500,000
Co-Chairman and Chief Executive Officer [Member] | Note Conversion and Stock Purchase Agreement [Member] | Common Stock [Member]
Related Party Transaction [Line Items]
Promissory note converted to shares	1,860,810

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Operating loss carryforwards, latest expiration year	2038
Operating loss carryforwards, expiration date	various years through 2038
Operating loss carryforwards	$ 67,200,000	$ 64,900,000
Increase in operating loss carryforwards	2,300,000
Net deferred tax asset recognized	$ 0
Change period for unrecognized tax benefits	12 months
Net decrease in deferred tax assets		8,819,000
Increase in deferred tax assets		724,000
Decrease in deferred tax assets due to change in tax rate		$ 9,543,000
Statutory federal income tax rate	21.00%	35.00%

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Statutory Federal Income Tax Rate and Effective Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory federal income tax rate	21.00%	35.00%
Permanent items	6.00%	(11.00%)
State income taxes, net of federal taxes	4.00%	(7.00%)
Foreign	(2.00%)	(3.00%)
Change in valuation allowance	(27.00%)	175.00%
Change in tax rates	0.00%	(189.00%)
Tax credits claimed	(1.00%)	(0.00%)
Other	(1.00%)	0.00%
Effective income tax rate	0.00%	0.00%

Income Taxes - Summary of Signi

Income Taxes - Summary of Significant Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 17,569	$ 16,842
Stock based compensation	2,437	2,695
Research and development tax credit	2,729	2,696
Other	260	192
Non-current deferred tax assets	22,995	22,425
Valuation allowances	(22,995)	(22,425)
Net deferred tax assets	$ 0	$ 0

Income Taxes - Summary of Compo

Income Taxes - Summary of Components of Provision for Income Taxes (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current	$ 0	$ 0
Deferred	0	0
Total	$ 0	$ 0

Stock Options and Warrants - St

Stock Options and Warrants - Stock Options - Additional Information (Detail)	2 Months Ended	12 Months Ended
	Dec. 31, 2009shares	Dec. 31, 2018USD ($)Optionee$ / sharesshares	Dec. 31, 2017$ / sharesshares	Dec. 31, 2016shares	Dec. 31, 2010shares	Dec. 31, 2006shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value, per share | $ / shares		$ 1.17	$ 0.93
Unrecognized compensation expense related to stock options | $		$ 2,800,000
Unrecognized compensation cost related to unvested shares expected to be recognized, weighted-average period		1 year 9 months 18 days
2006 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiry of options		10 years
Stock options expiration date		Nov. 16, 2016
Options granted to employees, directors and consultants		0
2006 Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options that may be granted						100,000
2010 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiry of options		10 years
2010 Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options that may be granted					9,700,000
Outside Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiry of options		10 years
Options granted to employees, directors and consultants	68,384
Award vesting terms		50 months
Number of options outstanding		12,634	50,730	50,730
Number of options exercised, canceled or expired		55,750
2006 Plan and 2010 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted to employees, directors and consultants		2,568,842	1,145,568
Number of options outstanding		4,354,708	2,245,349	1,460,076
Stock options exercised		140,968
Weighted average exercise price per share of options exercised | $ / shares		$ 1.13
2006 Plan and 2010 Plan [Member] | Optionees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of optionees | Optionee		4
Stock options exercised		140,968
Weighted average exercise price per share of options exercised | $ / shares		$ 1.13
Total exercise price of options exercised | $		$ 160,000
Aggregate intrinsic value of options exercised | $		$ 60,000
Weighted average intrinsic value of options exercised per share | $ / shares		$ 0.42
2006 Plan and 2010 Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiry of options		10 years

Stock Options and Warrants - Sc

Stock Options and Warrants - Schedule of Total Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,681	$ 1,384
Cost of Sales [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	57	23
Research and Development [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	641	637
Selling and Marketing [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	54	41
General and Administrative [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 929	$ 683

Stock Options and Warrants - Fa

Stock Options and Warrants - Fair Value of Stock Option Award, Weighted Average Assumptions (Detail) - Options Available for Future Grant [Member]	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Significant assumptions (weighted average):
Risk-free interest rate at grant date	2.72%	1.95%
Expected stock price volatility	92.68%	96.71%
Expected dividend payout	0.00%	0.00%
Expected option life based on management's estimate	5 years 8 months 12 days	5 years 8 months 15 days

Stock Options and Warrants - Su

Stock Options and Warrants - Summary of Changes in Options Outstanding and Related Exercise Prices (Detail)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number Outstanding | shares	4,354,708
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	8 years 7 months 13 days
Options Outstanding, Weighted Average Exercise Price	$ 3.95
Options Exercisable and Vested, Number Exercisable | shares	1,812,251
Options Exercisable and Vested, Weighted Average Remaining Contractual Life (Years)	8 years
Options Exercisable and Vested, Weighted Average Exercise Price	$ 7.08
$1.09-$1.49 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding Exercise Prices, Lower Range Limit	1.09
Options Outstanding Exercise Prices, Upper Range Limit	$ 1.49
Options Outstanding, Number Outstanding | shares	667,059
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	8 years 3 months 10 days
Options Outstanding, Weighted Average Exercise Price	$ 1.11
Options Exercisable and Vested, Number Exercisable | shares	385,903
Options Exercisable and Vested, Weighted Average Remaining Contractual Life (Years)	8 years 3 months 25 days
Options Exercisable and Vested, Weighted Average Exercise Price	$ 1.12
$1.50-$1.55 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding Exercise Prices, Lower Range Limit	1.50
Options Outstanding Exercise Prices, Upper Range Limit	$ 1.55
Options Outstanding, Number Outstanding | shares	996,944
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	9 years 2 months 12 days
Options Outstanding, Weighted Average Exercise Price	$ 1.51
Options Exercisable and Vested, Number Exercisable | shares	250,694
Options Exercisable and Vested, Weighted Average Remaining Contractual Life (Years)	9 years 2 months 12 days
Options Exercisable and Vested, Weighted Average Exercise Price	$ 1.51
$1.56-$1.59 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding Exercise Prices, Lower Range Limit	1.56
Options Outstanding Exercise Prices, Upper Range Limit	$ 1.59
Options Outstanding, Number Outstanding | shares	1,354,389
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	9 years 7 months 13 days
Options Outstanding, Weighted Average Exercise Price	$ 1.58
Options Exercisable and Vested, Number Exercisable | shares	228,138
Options Exercisable and Vested, Weighted Average Remaining Contractual Life (Years)	9 years 7 months 13 days
Options Exercisable and Vested, Weighted Average Exercise Price	$ 1.58
$1.60-$3.03 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding Exercise Prices, Lower Range Limit	1.60
Options Outstanding Exercise Prices, Upper Range Limit	$ 3.03
Options Outstanding, Number Outstanding | shares	452,594
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	8 years 2 months 19 days
Options Outstanding, Weighted Average Exercise Price	$ 2.03
Options Exercisable and Vested, Number Exercisable | shares	283,299
Options Exercisable and Vested, Weighted Average Remaining Contractual Life (Years)	7 years 11 months 26 days
Options Exercisable and Vested, Weighted Average Exercise Price	$ 2.09
$3.04-$289.50 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding Exercise Prices, Lower Range Limit	3.04
Options Outstanding Exercise Prices, Upper Range Limit	$ 289.50
Options Outstanding, Number Outstanding | shares	883,722
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	6 years 10 months 28 days
Options Outstanding, Weighted Average Exercise Price	$ 13.45
Options Exercisable and Vested, Number Exercisable | shares	664,217
Options Exercisable and Vested, Weighted Average Remaining Contractual Life (Years)	6 years 9 months 18 days
Options Exercisable and Vested, Weighted Average Exercise Price	$ 16.65

Stock Options and Warrants - _2

Stock Options and Warrants - Summary of Changes in Options Outstanding and Related Exercise Prices for Shares of Company's Common Stock Options Issued (Detail) - USD ($) $ / shares in Units, $ in Thousands	2 Months Ended	12 Months Ended
	Dec. 31, 2009	Dec. 31, 2018	Dec. 31, 2017
2006 Plan and 2010 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Outstanding, Beginning balance		2,245,349	1,460,076
Number of Options, Granted		2,568,842	1,145,568
Number of Options, Exercised		(140,968)
Number of Options, Canceled or expired		(318,515)	(360,295)
Number of Options, Outstanding, Ending balance		4,354,708	2,245,349
Number of Options, Options vested and expected to vest Ending Balance		4,056,445
Number of Options, Options exercisable Ending Balance		1,812,251
Weighted Average Exercise Price Per Share, Outstanding, Beginning balance		$ 8.25	$ 13.21
Weighted Average Exercise Price Per Share, Granted		1.56	1.14
Weighted Average Exercise Price Per Share, Exercised		1.13
Weighted Average Exercise Price Per Share, Canceled or expired		16.21	5.80
Weighted Average Exercise Price Per Share, Outstanding, Ending balance		3.95	$ 8.25
Weighted Average Exercise Price, Options vested or expected to vest Ending Balance		4.12
Weighted Average Exercise Price, Options exercisable Ending Balance		$ 7.08
Weighted Average Remaining Contractual Term, Options Outstanding Ending Balance		8 years 7 months 13 days
Weighted Average Remaining Contractual Term, Options vested or expected to vest Ending Balance		8 years 6 months 29 days
Weighted Average Remaining Contractual Term, Options exercisable Ending Balance		8 years
Aggregate Intrinsic Value, Options outstanding, Ending balance		$ 299
Aggregate Intrinsic Value, Options vested or expected to vest Ending Balance		290
Aggregate Intrinsic Value, Options exercisable Ending Balance		$ 162
Outside Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Outstanding, Beginning balance		50,730	50,730
Number of Options, Granted	68,384
Number of Options, Canceled or expired		(38,096)
Number of Options, Outstanding, Ending balance		12,634	50,730
Weighted Average Exercise Price Per Share, Outstanding, Beginning balance		$ 92.31	$ 92.31
Weighted Average Exercise Price Per Share, Canceled or expired		93
Weighted Average Exercise Price Per Share, Outstanding, Ending balance		$ 90.23	$ 92.31
Weighted Average Remaining Contractual Term, Options exercisable Ending Balance		10 months 24 days

Stock Options and Warrants - _3

Stock Options and Warrants - Summary of Changes in Restricted Stock Award Activity (Detail) - Under 2006 Plan and 2010 Plan [Member] - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Granted	9,855	30,643
Number of Shares, Vested	(9,855)	(30,643)
Weighted Average Grant Date Fair Value, Granted	$ 1.55	$ 1.60
Weighted Average Grant Date Fair Value, Vested	$ 1.55	$ 1.60

Stock Options and Warrants - Re

Stock Options and Warrants - Restricted Stock Awards - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,681,000	$ 1,384,000
Under 2006 Plan and 2010 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant-date fair value of restricted stock awards	15,000	49,000
Stock-based compensation expense	15,000	49,000
Unrecognized compensation costs	$ 0	$ 0

Stock Options and Warrants - Wa

Stock Options and Warrants - Warrants Issued in Connection with October 2014 Financing - Additional Information (Detail) - Placement Agent Warrants [Member]	Dec. 31, 2018$ / shares	Nov. 25, 2014$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing price of common stock	$ 1.53
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing price of common stock	$ 1.75
Warrant Exercise Price [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants and rights outstanding, measurement input	1.75	1.75
Stock Price Volatility [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants and rights outstanding, measurement input	94.2
Risk Free Interest Rate [Member] | U.S. Treasury Notes [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants and rights outstanding, measurement input	2.59
Options and Warrant Expected Term [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding term	1 year 3 months 14 days
Dividend Rate [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants and rights outstanding, measurement input	0

Stock Options and Warrants - _4

Stock Options and Warrants - Fair Value of the Warrant Liabilities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Change in fair value of warrant liability	$ (1,368,000)	$ 1,068,000
October 2014 Financing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Change in fair value of warrant liability	$ (1,000)	$ 0

Stock Options and Warrants - Pl

Stock Options and Warrants - Placement Agent Warrants Price Adjustment - Additional Information (Detail)	Dec. 31, 2018$ / sharesshares	Dec. 31, 2017shares	Dec. 31, 2016shares	Nov. 25, 2014$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	3,951,052	4,001,469	7,321,468
Placement Agent Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding	2,483
Placement Agent Warrants [Member] | Warrant Exercise Price [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants and rights outstanding, measurement input | $ / shares	1.75			1.75

Stock Options and Warrants - _5

Stock Options and Warrants - Warrants Issued in Connection with March 2016 Financing - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Change in fair value of warrant liability expense (income) | $	$ (1,368)	$ 1,068
Warrants outstanding | shares	3,951,052	4,001,469	7,321,468
Series-A and Placement Agent Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding | shares	3,948,569
Series-A and Placement Agent Warrants [Member] | Warrant Exercise Price [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants and rights outstanding, measurement input		1.75
March 2016 Financing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Change in fair value of warrant liability expense (income) | $	$ (1,400)	$ 1,100
March 2016 Financing [Member] | Series-A and Placement Agent Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing price of common stock	$ 1.53
March 2016 Financing [Member] | Series-A and Placement Agent Warrants [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing price of common stock	$ 1.75
March 2016 Financing [Member] | Series-A and Placement Agent Warrants [Member] | Warrant Exercise Price [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants and rights outstanding, measurement input	1.75
March 2016 Financing [Member] | Series-A and Placement Agent Warrants [Member] | Stock Price Volatility [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants and rights outstanding, measurement input	94.2
March 2016 Financing [Member] | Series-A and Placement Agent Warrants [Member] | Risk Free Interest Rate [Member] | U.S. Treasury Notes [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants and rights outstanding, measurement input	2.48
March 2016 Financing [Member] | Series-A and Placement Agent Warrants [Member] | Options and Warrant Expected Term [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding term	2 years 2 months 15 days
March 2016 Financing [Member] | Series-A and Placement Agent Warrants [Member] | Dividend Rate [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants and rights outstanding, measurement input	0

Stock Options and Warrants - _6

Stock Options and Warrants - Warrants Issued with Common Stock - Additional Information (Detail) - $ / shares	Mar. 12, 2013	Jan. 22, 2013	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock sold	33,334	67,500
Warrants outstanding converted into common stock	16,667	33,750
Warrants exercisable price	$ 30	$ 30	$ 1.75
Warrant term		5 years
Expiration date of warrants			Jan. 31, 2018
Co-Chairman and Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding converted into common stock	1,667
Warrant term	5 years
Expiration date of warrants			Mar. 31, 2018

Stock Options and Warrants - _7

Stock Options and Warrants - Summary of Outstanding Warrants Related to Warrant Transactions (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Class of Warrant or Right [Line Items]
Number of Shares, Outstanding, Beginning balance	4,001,469	7,321,468
Warrants, Forfeited/Cancelled	(50,417)	(3,319,999)
Number of Shares, Outstanding, Ending balance	3,951,052	4,001,469
Weighted Average Exercise Price, Forfeited/Cancelled	$ 30	$ 1.75
Weighted Average Exercise Price, Outstanding, Ending balance	1.75
Minimum [Member]
Class of Warrant or Right [Line Items]
Weighted Average Exercise Price, Outstanding, Beginning balance	1.75	1.75
Weighted Average Exercise Price, Outstanding, Ending balance		1.75
Maximum [Member]
Class of Warrant or Right [Line Items]
Weighted Average Exercise Price, Outstanding, Beginning balance	30	30
Weighted Average Exercise Price, Outstanding, Ending balance		30
Weighted Average [Member]
Class of Warrant or Right [Line Items]
Weighted Average Exercise Price, Outstanding, Beginning balance	2.94	2.40
Weighted Average Exercise Price, Forfeited/Cancelled	30	1.75
Weighted Average Exercise Price, Outstanding, Ending balance	$ 1.75	$ 2.94
Jan 2013 Financing [Member]
Class of Warrant or Right [Line Items]
Number of Shares, Outstanding, Beginning balance	33,750	33,750
Warrants, Forfeited/Cancelled	(33,750)
Number of Shares, Outstanding, Ending balance		33,750
Mar 2013 Financing [Member]
Class of Warrant or Right [Line Items]
Number of Shares, Outstanding, Beginning balance	16,667	16,667
Warrants, Forfeited/Cancelled	(16,667)
Number of Shares, Outstanding, Ending balance		16,667
March 2016 Financing [Member] | Series A Common Stock [Member]
Class of Warrant or Right [Line Items]
Number of Shares, Outstanding, Beginning balance	3,605,713	3,605,713
Number of Shares, Outstanding, Ending balance	3,605,713	3,605,713
March 2016 Financing [Member] | Series C Common Stock [Member]
Class of Warrant or Right [Line Items]
Number of Shares, Outstanding, Beginning balance		3,319,999
Warrants, Forfeited/Cancelled		(3,319,999)
March 2016 Financing [Member] | Placement Agent [Member]
Class of Warrant or Right [Line Items]
Number of Shares, Outstanding, Beginning balance	342,856	342,856
Number of Shares, Outstanding, Ending balance	342,856	342,856
October 2014 Financing [Member] | Placement Agent [Member]
Class of Warrant or Right [Line Items]
Number of Shares, Outstanding, Beginning balance	2,483	2,483
Number of Shares, Outstanding, Ending balance	2,483	2,483

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018USD ($)ft²	Dec. 31, 2017USD ($)Customer	Oct. 31, 2018ft²	Sep. 30, 2018ft²	Feb. 22, 2017	Jan. 01, 2013ft²	Jul. 01, 2011ft²	Mar. 01, 2011ft²
Commitments And Contingencies [Line Items]
Rent expense	$ 322,000	$ 345,000
Supplier Concentration Risk [Member] | Vendor One [Member] | Cost of Goods Total [Member]
Commitments And Contingencies [Line Items]
Concentration risk percentage	21.00%	10.00%
Number of customers accounted for more than 10% | Customer		0
Biomedical Market [Member] | Customer Concentration Risk [Member] | Major customer 1 [Member] | Sales Revenue Segment [Member]
Commitments And Contingencies [Line Items]
Concentration risk percentage	33.00%	35.00%
Biomedical Market [Member] | Customer Concentration Risk [Member] | Major customer 2 [Member] | Sales Revenue Segment [Member]
Commitments And Contingencies [Line Items]
Concentration risk percentage	24.00%
Oceanside Facility [Member]
Commitments And Contingencies [Line Items]
Current square feet of leased office and laboratory | ft²	8,215
Lease expiration period	2021-12
Option to terminate of lease	Jan. 1, 2020
Advanced notice required to terminate lease	6 months
Current base rent	$ 10,000
Percentage of increase in monthly base rent	3.00%
Frederick [Member]
Commitments And Contingencies [Line Items]
Current square feet of leased office and laboratory | ft²	13,320			8,280
Lease expiration period	2025-11
Current base rent	$ 17,000
Additional square feet of leased office and laboratory | ft²			5,040
Priestly Drive [Member]
Commitments And Contingencies [Line Items]
Current square feet of leased office and laboratory | ft²						9,848	8,199	4,653
Current base rent	$ 13,000
Percentage of increase in monthly base rent	3.00%
Expiry of lease	Feb. 29, 2016
Expiry of lease additional	1 year				3 years
Initial monthly base rent	$ 5,000

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Future Minimum Lease Payments Required under Operating Leases that Have Initial or Remaining Non-Cancelable Lease Terms in Excess of One Year (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Operating Leases Future Minimum Payments Due [Abstract]
2019	$ 491
2020	368
2021	347
2022	220
2023	227
Thereafter	454
Total	$ 2,107

Segments and Geographic Infor_3

Segments and Geographic Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018SegmentUnitsProduct
Segment Reporting [Abstract]
Number reporting segments | Segment	3
Number of business units | Units	2
Human cell culture products | Product	200

Segments and Geographic Infor_4

Segments and Geographic Information - Revenues, Expenses and Operating Income (Loss) by Market Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Total revenues	$ 11,089	$ 7,456
Expenses:
Total operating expenses	14,563	12,398
Operating income (loss):
Total operating income (loss)	(3,474)	(4,942)
Cosmetic Market [Member]
Revenues:
Total revenues	1,812	2,256
Expenses:
Total operating expenses	2,637	2,634
Operating income (loss):
Total operating income (loss)	(825)	(378)
Biomedical Market [Member]
Revenues:
Total revenues	9,277	5,200
Expenses:
Total operating expenses	6,022	3,373
Operating income (loss):
Total operating income (loss)	3,255	1,827
Therapeutic Market [Member]
Expenses:
Total operating expenses	5,904	6,391
Operating income (loss):
Total operating income (loss)	$ (5,904)	$ (6,391)

Segments and Geographic Infor_5

Segments and Geographic Information - Summary of Significant Revenues in Following Regions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 11,089	$ 7,456
North America [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	10,160	6,347
Asia [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	612	728
Europe [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	293	354
All Other Regions [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 24	$ 27

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail)	Feb. 28, 2019$ / sharesshares	Jan. 21, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)shares	Aug. 08, 2018USD ($)
Subsequent Event [Line Items]
Non-convertible promissory note, principal amount			$ 2,000,000
Accrued interest on promissory note			$ 45,000
Conversion of debt				$ 2,756,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Stock options, granted | shares	1,100,000
Stock options, exercise price | $ / shares	$ 1.51
Options vesting	0.083
Vesting date	May 28, 2019
Remaining vest over the period	33 months
Common Stock [Member]
Subsequent Event [Line Items]
Conversion of debt, shares | shares				1,575,000
Conversion of debt				$ 2,000
Co-Chairman and Chief Executive Officer [Member] | Note Conversion Agreement [Member]
Subsequent Event [Line Items]
Related party transaction, description			The outstanding principal amount under the New Note accrues interest at a rate of four and one-half percent (4.5%) per annum. The New Note is due and payable on January 15, 2020, but may be pre-paid by the Company without penalty at any time.
Co-Chairman and Chief Executive Officer [Member] | Note Conversion Agreement [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt cancelled and surrendered		$ 1,000,000
Non-convertible promissory note, principal amount		1,000,000
Accrued interest on promissory note		$ 49,000
Conversion price | $ / shares		$ 1.75
Co-Chairman and Chief Executive Officer [Member] | Note Conversion Agreement [Member] | Common Stock [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Conversion of debt, shares | shares		599,222
Co-Chairman and Chief Executive Officer [Member] | Note Conversion Agreement [Member] | Unsecured Non-convertible Promissory Note [Member]
Subsequent Event [Line Items]
Non-convertible promissory note, principal amount					$ 1,000,000
Co-Chairman and Chief Executive Officer [Member] | Note Conversion Agreement [Member] | Unsecured Non-convertible Promissory Note [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Conversion of debt		$ 1,000,000
Annual interest rate		4.50%
Maturity date		Jan. 15, 2020