Apollo Endosurgery (APEN) 10-Q 1 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 29, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-35706
Entity Registrant Name	APOLLO ENDOSURGERY, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	16-1630142
Entity Address, Address Line One	1120 S. Capital of Texas Highway
Entity Address, Address Line Two	Building 1, Suite #300
Entity Address, City or Town	Austin
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78746
City Area Code	512
Local Phone Number	279-5100
Title of 12(b) Security	Common stock, par value $0.001 per share
Trading Symbol	APEN
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		39,492,526
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001251769
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 27,353	$ 36,235
Accounts receivable, net of allowance for doubtful accounts of $668 and $634, respectively	10,290	8,218
Inventory	11,317	10,306
Prepaid expenses and other current assets	4,952	3,771
Total current assets	53,912	58,530
Restricted cash	1,121	965
Property, equipment and right-of-use assets, net	5,586	6,221
Goodwill	5,290	5,290
Intangible assets, net of accumulated amortization of $14,434 and $13,231, respectively	4,821	6,017
Other assets	352	414
Total assets	71,082	77,437
Current liabilities:
Accounts payable	4,512	3,675
Accrued expenses	9,251	7,357
Current portion of long-term debt	1,129	636
Total current liabilities	14,892	11,668
Long-term debt	34,644	37,192
Convertible debt	19,463	19,387
Long-term liabilities	2,175	2,439
Total liabilities	71,174	70,686
Commitments and contingencies
Stockholders' (deficit) equity:
Common stock; $0.001 par value; 100,000,000 shares authorized; 29,829,697 and 25,819,329 shares issued and outstanding at September 30, 2021 and December 31, 2020, respectively	30	26
Additional paid-in capital	285,013	276,569
Accumulated other comprehensive income	1,915	2,929
Accumulated deficit	(287,050)	(272,773)
Total stockholders' (deficit) equity	(92)	6,751
Total liabilities and stockholders' (deficit) equity	$ 71,082	$ 77,437

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 668	$ 634
Accumulated amortization	$ 14,434	$ 13,231
Common stock, par value (USD per share)	$ 0.001	$ 0.001
Common stock, shares authorized (shares)	100,000,000	100,000,000
Common stock, shares issued (shares)	29,829,697	25,819,329
Common stock, shares outstanding (shares)	29,829,697	25,819,329

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Revenues	$ 16,351	$ 12,826	$ 46,818	$ 29,188
Cost of sales	7,124	5,840	20,961	14,136
Gross margin	9,227	6,986	25,857	15,052
Operating expenses:
Sales and marketing	6,123	4,178	16,918	12,773
General and administrative	4,574	2,374	13,981	7,870
Research and development	2,567	1,522	7,045	5,484
Amortization of intangible assets	467	486	1,412	1,472
Total operating expenses	13,731	8,560	39,356	27,599
Loss from operations	(4,504)	(1,574)	(13,499)	(12,547)
Other (income) expenses:
Interest expense, net	1,342	1,335	4,028	3,895
Gain on forgiveness of PPP loan	0	0	(2,852)	0
Other (income) expense, net	721	(353)	(618)	2,574
Net loss before income taxes	(6,567)	(2,556)	(14,057)	(19,016)
Income tax expense	90	41	220	90
Net loss	(6,657)	(2,597)	(14,277)	(19,106)
Other comprehensive (loss)/income:
Foreign currency translation	388	(253)	(1,014)	2,150
Comprehensive loss	$ (6,269)	$ (2,850)	$ (15,291)	$ (16,956)
Net loss per share, basic (USD per share)	$ (0.23)	$ (0.11)	$ (0.52)	$ (0.88)
Net loss per share, diluted (USD per share)	$ (0.23)	$ (0.11)	$ (0.52)	$ (0.88)
Shares used in computing net loss per share, basic (shares)	29,020,443	23,110,524	27,542,182	21,798,336
Shares used in computing net loss per share, diluted (shares)	29,020,443	23,110,524	27,542,182	21,798,336

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Changes in Stockholders’ (Deficit) Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2019		20,951,963
Beginning balance at Dec. 31, 2019	$ 2,123	$ 21	$ 250,634	$ 1,630	$ (250,162)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)		1,150
Exercise of common stock options	2		2
Issuance of restricted stock and performance stock units (in shares)		79,766
Issuance of common stock for convertible debt interest (in shares)		164,797
Issuance of common stock for convertible debt interest	467		467
Issuance of common stock, net of issuance costs (in shares)		2,480,000
Issuance of common stock, net of issuance costs	23,262	$ 3	23,259
Conversion of convertible debt	0
Stock-based compensation	1,521		1,521
Foreign currency translation	2,150			2,150
Net loss	(19,106)				(19,106)
Ending balance (in shares) at Sep. 30, 2020		23,677,676
Ending balance at Sep. 30, 2020	10,419	$ 24	275,883	3,780	(269,268)
Beginning balance (in shares) at Jun. 30, 2020		21,196,387
Beginning balance at Jun. 30, 2020	(10,579)	$ 21	252,038	4,033	(266,671)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock and performance stock units (in shares)		1,289
Issuance of common stock, net of issuance costs (in shares)		2,480,000
Issuance of common stock, net of issuance costs	23,262	$ 3	23,259
Stock-based compensation	586		586
Foreign currency translation	(253)			(253)
Net loss	(2,597)				(2,597)
Ending balance (in shares) at Sep. 30, 2020		23,677,676
Ending balance at Sep. 30, 2020	$ 10,419	$ 24	275,883	3,780	(269,268)
Beginning balance (in shares) at Dec. 31, 2020	25,819,329	25,819,329
Beginning balance at Dec. 31, 2020	$ 6,751	$ 26	276,569	2,929	(272,773)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)		643,569
Exercise of common stock options	2,352	$ 1	2,351
Exercise of shares for warrants (in shares)		2,668,247
Exercise of common stock warrants	2	$ 3	(1)
Issuance of restricted stock and performance stock units (in shares)		431,047
Issuance of common stock for convertible debt interest (in shares)		244,861
Issuance of common stock for convertible debt interest	1,229		1,229
Conversion of convertible debt (in shares)		22,644
Conversion of convertible debt	74		74
Stock-based compensation	4,791		4,791
Foreign currency translation	(1,014)			(1,014)
Net loss	$ (14,277)				(14,277)
Ending balance (in shares) at Sep. 30, 2021	29,829,697	29,829,697
Ending balance at Sep. 30, 2021	$ (92)	$ 30	285,013	1,915	(287,050)
Beginning balance (in shares) at Jun. 30, 2021		28,624,979
Beginning balance at Jun. 30, 2021	2,714	$ 29	281,551	1,527	(280,393)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)		330,564
Exercise of common stock options	1,304	$ 1	1,303
Exercise of shares for warrants (in shares)		624,436
Issuance of restricted stock and performance stock units (in shares)		178,109
Issuance of common stock for convertible debt interest (in shares)		71,609
Issuance of common stock for convertible debt interest	614		614
Stock-based compensation	1,545		1,545
Foreign currency translation	388			388
Net loss	$ (6,657)				(6,657)
Ending balance (in shares) at Sep. 30, 2021	29,829,697	29,829,697
Ending balance at Sep. 30, 2021	$ (92)	$ 30	$ 285,013	$ 1,915	$ (287,050)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Changes in Stockholders’ (Deficit) Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Statement of Stockholders' Equity [Abstract]
Issuance costs	$ 1,721	$ 1,721

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net loss	$ (14,277)	$ (19,106)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,484	2,820
Gain on forgiveness of PPP loan	(2,852)	0
Amortization of deferred financing costs	377	487
Non-cash interest	1,304	1,104
Provision for doubtful accounts receivable	62	34
Inventory impairment	50	0
Stock-based compensation	4,791	1,521
Unrealized foreign exchange on intercompany payables	(856)	2,366
Changes in operating assets and liabilities:
Accounts receivable	(2,312)	930
Inventory	(1,077)	(1,286)
Prepaid expenses and other assets	(951)	387
Accounts payable and accrued expenses	3,142	(7,274)
Net cash used in operating activities	(10,115)	(18,017)
Cash flows from investing activities:
Purchases of property and equipment	(743)	(431)
Purchases of intangibles and other assets	(218)	(117)
Net cash used in investing activities	(961)	(548)
Cash flows from financing activities:
Proceeds from exercise of stock options	2,352	2
Proceeds from exercise of warrants	2	0
Proceeds from issuance of common stock	0	23,262
Proceeds from long-term debt	0	2,824
Payments of deferred financing costs	0	(260)
Net cash provided by financing activities	2,354	25,828
Effect of exchange rate changes on cash	(4)	11
Net change in cash, cash equivalents and restricted cash	(8,726)	7,274
Cash, cash equivalents and restricted cash at beginning of year	37,200	30,921
Cash, cash equivalents and restricted cash at end of period	28,474	38,195
Supplemental disclosure of cash flow information:
Cash paid for interest	2,359	2,398
Cash paid for income taxes	36	52
Right-of-use assets recognized in exchange for lease obligations (non-cash)	(577)	1,152
Gain on forgiveness of PPP loan (non-cash)	2,852	0
Issuance of common stock for convertible debt interest (non-cash)	1,229	467
Issuance of common stock from conversion of convertible debt (non-cash)	$ 74	$ 0

Organization and Business Descr

Organization and Business Description	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Business Description	Organization and Business Description Apollo Endosurgery, Inc. is a Delaware corporation with both domestic and foreign wholly-owned subsidiaries. Throughout these Notes, "Apollo" and the "Company" refer to Apollo Endosurgery, Inc. and its consolidated subsidiaries. Apollo is a medical technology company primarily focused on the development of next-generation, less invasive medical devices to advance gastrointestinal therapeutic endoscopy. The Company develops and distributes devices that are used by surgeons and gastroenterologists for a variety of procedures related to gastrointestinal conditions including closure of gastrointestinal defects, managing gastrointestinal complications and the treatment of obesity. The Company's core products include the OverStitch® Endoscopic Suturing System, the OverStitch Sx® Endoscopic Suturing System, X-Tack® Endoscopic HeliX Tacking System (collectively "ESS") and the ORBERA® Intragastric Balloon ("IGB"). The Company has offices in the United Kingdom and Italy that oversee commercial activities outside the U.S. and a products manufacturing facility in Costa Rica. All other activities are managed and operated from facilities in Austin, Texas.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies (a) Basis of Presentation The Company prepared its interim condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP"). They do not include all of the information and footnotes required by GAAP for complete financial statements. The accompanying condensed consolidated financial statements include the Company's accounts and the accounts of its wholly-owned subsidiaries. The Company has eliminated all intercompany balances and transactions. The Company has made estimates and judgments affecting the amounts reported in its condensed consolidated financial statements and the accompanying notes. The actual results that the Company experiences may differ materially from the Company's estimates. The accounting estimates that require the Company's most significant, difficult and subjective judgments include revenue recognition and inventory valuation. (b) Unaudited Interim Results In management's opinion, the unaudited financial information for the interim periods presented includes all adjustments necessary for a fair presentation of the results of operations, financial position, and cash flows. All adjustments are of a normal recurring nature unless otherwise disclosed. Revenues, expenses, assets and liabilities can vary during each quarter of the year. Therefore, the results and trends in these interim financial statements may not be the same as those for the full year. This interim information should be read in conjunction with the audited consolidated financial statements in the Company's Annual Report on Form 10-K for the year ended December 31, 2020. (c) Recent Accounting Pronouncements In March 2020, ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting

Concentrations

Concentrations	9 Months Ended
	Sep. 30, 2021
Risks and Uncertainties [Abstract]
Concentrations	ConcentrationsConsolidated financial instruments that potentially subject the Company to a concentration of credit risk principally consist of cash and cash equivalents and accounts receivable. At September 30, 2021, the Company's cash, cash equivalents and restricted cash are held in deposit accounts at five different banks totaling $28,474. The Company has not experienced any losses in such accounts, and management does not believe the Company is exposed to any significant credit risk. Management further believes that credit risk in the Company's accounts receivable is substantially mitigated by the Company's evaluation process, relatively short collection terms, and the high level of creditworthiness of its customers. The Company continually monitors the compliance of its customers with the Company's payment terms, but generally requires no collateral.The Company had one distributor customer representing 11% of the Company's net accounts receivable as of September 30, 2021, and no concentrations greater than 10% as of December 31, 2020. The Company had no single customer that comprised more than 10% of the Company's total revenues for the three and nine months ended September 30, 2021 or 2020.

Inventory

Inventory	9 Months Ended
	Sep. 30, 2021
Inventory Disclosure [Abstract]
Inventory	Inventory Inventory consists of the following as of: September 30, 2021 December 31, 2020 (unaudited) Raw materials $ 3,037 $ 2,344 Work in progress 1,141 558 Finished goods 7,139 7,404 Total inventory $ 11,317 $ 10,306 Finished goods included $117 of consigned inventory at September 30, 2021.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	9 Months Ended
	Sep. 30, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid Expenses and Other Current AssetsIncluded in prepaid expenses and other current assets as of September 30, 2021 and December 31, 2020 is $2,947 and $2,760 for the final installment due in December 2021 from the sale of the surgical product line.

Property, Equipment and Right-o

Property, Equipment and Right-of-Use Assets	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Property, Equipment and Right-of-Use Assets	Property, Equipment and Right-of-Use Assets Property, equipment and right-of-use assets consists of the following: Depreciable Lives September 30, 2021 December 31, 2020 (unaudited) Equipment 5 years $ 7,483 $ 7,452 Right-of-use assets 1-8 years 3,449 4,031 Furniture, fixtures and tooling 4-8 years 2,471 2,156 Computer hardware 3-5 years 1,305 1,244 Leasehold improvements 3-7 years 2,052 1,744 Construction in process 408 466 17,168 17,093 Less accumulated depreciation (11,582) (10,872) Property, equipment and right-of-use assets, net $ 5,586 $ 6,221 The Company recorded depreciation expense of $285 and $1,071 for the three and nine months ended September 30, 2021 and $435 and $1,346 for the three and nine months ended September 30, 2020, respectively. There were no impairment charges for the three and nine months ended September 30, 2021 or 2020. The Company has operating leases for office space in Texas, the United Kingdom, and Italy, and for the manufacturing facility in Costa Rica. The Company also has various operating lease agreements for vehicles. As of September 30, 2021, the maturities of the Company's operating lease liabilities are as follows: 2021 $ 340 2022 791 2023 492 2024 443 2025 404 Thereafter 1,172 Total lease payments 3,642 Less imputed interest (923) Total operating lease liabilities $ 2,719 Operating lease liabilities of $653 are included in accrued expenses long-term liabilities

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Accrued Expenses	Accrued Expenses Accrued expenses consists of the following as of: September 30, 2021 December 31, 2020 (unaudited) Accrued employee compensation and expenses $ 5,449 $ 3,946 Accrued professional service fees 604 358 Lease liability 653 675 Accrued taxes 779 442 Accrued interest 307 616 Accrued returns and rebates 220 129 Other 1,239 1,191 Total accrued expenses $ 9,251 $ 7,357

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Long-term debt consists of the following as of: September 30, 2021 December 31, 2020 (unaudited) Term loan facility $ 35,000 $ 35,000 PPP loan — 2,824 Deferred interest 1,759 1,217 Deferred financing costs (986) (1,213) Less current portion (1,129) (636) Long-term debt $ 34,644 $ 37,192 Term Loan Facility In March 2019, the Company entered into a Term Loan Facility (the "Credit Agreement") with Solar Capital Ltd. ("Solar") to borrow $35,000. The Credit Agreement, as amended by the Seventh Amendment, provided a six-month extension of the interest only period and the maturity date if certain revenue milestones were achieved before December 2021. These revenue milestones were achieved as of March 31, 2021 and thus the Credit Agreement maturity was extended to March 1, 2025 with principal payments beginning in September 2022. The Credit Agreement bears interest at LIBOR, subject to a minimum floor, plus 7.5%. Principal payments are due on a straight-line basis after the interest-only period concludes. An additional 7.0% of the outstanding amount will be due at end of the loan term and an additional 5.5% fee will be due at the earlier of certain exit events specified in the Credit Agreement or if the Company achieves trailing twelve-month revenue of $100,000 before December 4, 2030. The Credit Agreement includes customary affirmative covenants, negative covenants and financial covenants, including a minimum liquidity requirement and minimum product revenues. In February 2021, the Company entered into the Eighth Amendment to the Credit Agreement which established the revenue covenant requirements for the year ended December 31, 2021. As of September 30, 2021, the Company was in compliance with all financial covenants. PPP Loan In March 2020, the CARES Act was signed into law providing certain economic aid packages for qualified entities. In April 2020, the Company was granted a loan of $2,824 under the Small Business Administration’s (“SBA”) Paycheck Protection Program (“PPP”) established under the CARES Act. In June 2021, the Company received forgiveness of the full amount of the $2,852 loan, inclusive of interest, from the SBA. Interest expense on the Company's long-term debt was $1,048 and $3,147 for the three and nine months ended September 30, 2021 and $1,054 and $3,144 for the three and nine months ended September 30, 2020, respectively. Principal payments of the Company's long-term debt are as follows: 2021 $ — 2022 4,516 2023 13,548 2024 13,548 2025 3,388 Thereafter — $ 35,000

Convertible Debt

Convertible Debt	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Convertible Debt	Convertible Debt Convertible debt consists of the following as of: September 30, 2021 December 31, 2020 (unaudited) Convertible debt $ 20,445 $ 20,519 Deferred financing costs (982) (1,132) Total convertible debt $ 19,463 $ 19,387 In August 2019, the Company issued $20,000 aggregate principal amount of 6.0% convertible senior debentures due 2026 (the "Convertible Debt"), primarily to existing stockholders and officers of the Company. Interest on the Convertible Debt is payable semi-annually in shares of the Company's common stock on January 1 and July 1 of each year at a rate of 6.0% per year. The number of shares of common stock required to settle the amount of interest payable will be based on the volume-weighted average price ("VWAP") of the Company's common stock for the 10 consecutive trading days immediately preceding the applicable interest payment date. However, in the event that the trailing 10-trading day VWAP of the Company's common stock is less than $2.50 per share, interest accrued and payable for the applicable interest payment period will accrete to the principal amount then outstanding. The Convertible Debt will mature on August 12, 2026 unless earlier converted or repaid in accordance with its terms. The Company issued 161,184 shares and 12,068 shares of the Company's common stock to holders of the Convertible Debt in January 2021 and May 2021, respectively, in fulfillment of accrued interest as of December 31, 2020. In July 2021, the Company issued 71,609 additional shares of common stock for accrued interest as of June 30, 2021. The Convertible Debt converts, at the option of the holders, into shares of the Company's common stock at an initial conversion price of $3.25 per share, subject to adjustment. If the VWAP of the Company's common stock has been at least $9.75 (subject to adjustment) for at least 20 trading days during any 30 consecutive trading day period, the Company may force the conversion of all or any part of the outstanding principal amount of the Convertible Debt, accrued and unpaid interest and any other amounts then owing, subject to certain conditions. In February 2021, $74 of the Convertible Debt, including accrued interest was converted into 22,644 shares of common stock. Interest expense on the Convertible Debt was $356 and $1,070 for the three and nine months ended September 30, 2021 and $388 and $1,144 for the three and nine months ended September 30, 2020, respectively.

Warrants

Warrants	9 Months Ended
	Sep. 30, 2021
Other Liabilities Disclosure [Abstract]
Warrants	Warrants Warrants consist of the following as of September 30, 2021: Warrant Expiration Date Number of shares Exercise price per share December 29, 2021 40,456 $ 13.70 February 27, 2022 163,915 $ 21.29 No expiration 13,744,504 $ 0.001 Total number of warrants outstanding 13,948,875 Weighted average exercise price of warrants outstanding $ 0.29 Pre-funded warrants were exercised into 2,668,247 shares of common stock in the nine months ended September 30, 2021.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation A summary of the stock option activity as of September 30, 2021 is presented below. Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Options outstanding, December 31, 2020 2,921,946 $ 3.86 7.6 years $ 1,664 Options granted 1,507,872 6.36 Options exercised (643,569) 3.66 Options forfeited (226,356) 3.27 Options outstanding, vested and expected to vest, September 30, 2021 3,559,893 $ 4.99 8.2 years $ 14,853 Options exercisable 1,430,480 $ 4.63 6.9 years $ 6,705 Shares subject to awards granted under the 2017 Plan which expire, are repurchased, or are canceled or forfeited will again become available for issuance under the 2017 Plan. The shares available will not be reduced by awards settled in cash or by shares withheld to satisfy tax withholding obligations. Only the net number of shares issued upon the exercise of options by means of a net exercise will be deducted from the shares available under the 2017 Plan. The fair value of stock option grants has been estimated at the date of grant using the Black-Scholes option pricing model with the following weighted average assumptions: Nine Months Ended Nine Months Ended Risk free interest rate 1.0% 0.4% Expected dividend yield —% —% Estimated volatility 81.1% 73.8% Expected life 6.1 years 5.8 years The aggregate intrinsic value in the tables above represents the total pre-tax value of the options shown, calculated as the difference between the Company’s closing stock price on September 30, 2021 and the exercise prices of the options shown, multiplied by the number of in-the money options. This is the aggregate amount that would have been received by the option holders if they had all exercised their options on September 30, 2021 and sold the shares thereby received at the closing price of the Company’s common stock on that date. This amount changes based on the closing price of the Company’s common stock. Additional information regarding options is as follows: Nine Months Ended Nine Months Ended Weighted-average grant date fair value of options granted during the period $ 4.40 $ 1.31 Aggregate intrinsic value of options exercised during the period $ 3,116 $ — In March 2021, the Company awarded 848,733 stock options to the Company’s chief executive officer in connection with the commencement of his employment. In August 2021, the Company awarded 150,000 stock options to the Company's chief financial officer in connection with the commencement of his employment. The option grant will vest over a period of four years, with one-quarter of the shares underlying the option vesting on the first anniversary of the grant date and the remainder vesting in equal monthly installments thereafter. In connection with the departure of two executive officers, the terms for the stock option vesting period and exercise period were modified which resulted in additional stock-based compensation of $26 and $222 for the three and nine months ended September 30, 2021, respectively. Unrecognized compensation expense related to unvested options was approximately $6,724 at September 30, 2021, with a weighted average remaining amortization period of 3.1 years. A summary of the restricted stock unit activity, including performance-based stock units, under the Company's Equity Plans as of September 30, 2021 is presented below. Units Weighted Average Grant Date Fair Value Aggregate Intrinsic Value Restricted stock units outstanding, December 31, 2020 664,666 $ 2.55 $ 2,260 Restricted stock units granted 1,111,437 6.53 Restricted stock units released (431,047) 3.97 Restricted stock units forfeited (130,135) 3.08 Restricted stock units outstanding, September 30, 2021 1,214,921 $ 5.63 $ 11,007 In March 2021, the Company awarded 707,278 performance-based restricted stock units to the Company’s chief executive officer in connection with the commencement of his employment. The performance-based restricted stock units vest in four equal tranches upon the achievement of revenue for the trailing four quarters equal to $50,000, $65,000, $80,000, and $95,000. The revenue milestone for the first tranche was achieved as of June 30, 2021. In August 2021, the Company awarded 80,000 time-based restricted stock units and 120,000 performance-based restricted stock units to the Company's chief financial officer in connection with the commencement of his employment. The time-based restricted stock units vest in four equal tranches upon completion of each year of employment. The performance-based restricted stock units vest in three equal tranches upon the achievement of revenue for the trailing four quarters equal to $70,000, $90,000, and $110,000. In connection with the departure of an executive officer, the vesting terms for restricted stock units outstanding were modified which resulted in additional stock-based compensation of $76 for the nine months ended September 30, 2021.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The provision for income taxes for the three and nine months ended September 30, 2021 and 2020 primarily consists of foreign income taxes. The Company has established a valuation allowance due to uncertainties regarding the realization of deferred tax assets based on the Company's lack of earnings history and potential limitations pursuant to changes in ownership under Internal Revenue Code Section 382. As of September 30, 2021, the Company has no unrecognized tax benefits or accrued interest or penalties associated with uncertain tax positions.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per ShareThe basic and diluted net loss per common share presented in the condensed consolidated statements of operations and comprehensive loss is calculated by dividing net loss by the weighted-average number of common shares outstanding during the period, without consideration for common stock equivalents. Potentially dilutive shares, which include warrants for the purchase of common stock, convertible debt, restricted stock units, including performance-based stock units, and options outstanding under the Company's equity incentive plans, are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive. Potentially dilutive securities that are not included in the calculation of diluted net loss per share attributable to common stockholders because to do so would be anti-dilutive are as follows (in common stock equivalent shares on a weighted-average basis): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Warrants for common stock 13,948,875 14,725,241 13,948,875 5,744,225 Convertible debt 6,299,433 6,385,483 6,293,791 6,292,599 Common stock options 3,494,676 3,009,913 3,039,021 2,459,202 Restricted stock units 1,127,964 677,605 847,081 437,640 24,870,948 24,798,242 24,128,768 14,933,666

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The carrying amounts of the Company's financial instruments, which primarily include cash, cash equivalents, and restricted cash, accounts receivable, accounts payable and accrued expenses, approximate their fair values due to their short maturities. The fair value of the Company's long-term debt and Convertible Debt is estimated by management to approximate $38,800 and $20,400, respectively at September 30, 2021. Management's estimates are based on comparisons of the characteristics of the Company's obligations, comparable ranges of interest rates on recently issued debt, and maturity. Such valuation inputs are considered a Level 3 measurement in the fair value valuation hierarchy. The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets; Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.

Segment and Geographic Informat

Segment and Geographic Information	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Segment and Geographic Information	Segment and Geographic InformationOperating segments are defined as components of an enterprise for which separate financial information is available and evaluated regularly by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company globally manages the business within one reportable segment. Segment information is consistent with how management reviews the business, makes investing and resource allocation decisions and assesses operating performance. Product sales by product group and geographic market, based on the location of the customer, whether the U.S. or outside the U.S. ("OUS") for the periods shown were as follows: Three Months Ended September 30, 2021 Three Months Ended September 30, 2020 (unaudited) U.S. OUS Total Revenues % Total Revenues U.S. OUS Total Revenues % Total Revenues ESS $ 6,722 $ 3,504 $ 10,226 62.5 % $ 4,734 $ 2,928 $ 7,662 59.7 % IGB 2,006 3,890 5,896 36.1 % 1,853 3,021 4,874 38.0 % Other 215 14 229 1.4 % 272 18 290 2.3 % Total revenues $ 8,943 $ 7,408 $ 16,351 100.0 % $ 6,859 $ 5,967 $ 12,826 100.0 % % Total revenues 54.7 % 45.3 % 53.5 % 46.5 % Nine Months Ended September 30, 2021 Nine Months Ended September 30, 2020 (unaudited) U.S. OUS Total Revenues % Total Revenues U.S. OUS Total Revenues % Total Revenues ESS $ 18,977 $ 10,512 $ 29,489 63.0 % $ 10,873 $ 7,211 $ 18,084 62.0 % IGB 5,570 11,042 16,612 35.5 % 3,511 6,688 10,199 34.9 % Other 689 28 717 1.5 % 854 51 905 3.1 % Total revenues $ 25,236 $ 21,582 $ 46,818 100.0 % $ 15,238 $ 13,950 $ 29,188 100.0 % % Total revenues 53.9 % 46.1 % 52.2 % 47.8 % Total distributor sales were 46.4% and 42.4% of total OUS revenues for the three and nine months ended September 30, 2021 and 30.4% and 31.4% for the three and nine months ended September 30, 2020, respectively. Sales in the next largest individual country outside the U.S. were 6.0%-7.0% of total revenues for the three and nine months ended September 30, 2021 compared to 8.0%-9.0% for the three and nine months ended September 30, 2020. The following table represents property, equipment and right-of-use assets based on the physical location of the asset: September 30, 2021 December 31, 2020 (unaudited) U.S. $ 1,832 $ 2,149 Costa Rica 3,485 3,641 Other 269 431 Total property, equipment and right-of-use assets, net $ 5,586 $ 6,221

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsIn October 2021, the Company issued and sold 9,660,000 shares of common stock, par value $0.001 per share, at a public offering price per share of $7.75 for aggregate gross proceeds of approximately $74,900.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Organization and Business Description	Apollo Endosurgery, Inc. is a Delaware corporation with both domestic and foreign wholly-owned subsidiaries. Throughout these Notes, "Apollo" and the "Company" refer to Apollo Endosurgery, Inc. and its consolidated subsidiaries. Apollo is a medical technology company primarily focused on the development of next-generation, less invasive medical devices to advance gastrointestinal therapeutic endoscopy. The Company develops and distributes devices that are used by surgeons and gastroenterologists for a variety of procedures related to gastrointestinal conditions including closure of gastrointestinal defects, managing gastrointestinal complications and the treatment of obesity. The Company's core products include the OverStitch® Endoscopic Suturing System, the OverStitch Sx® Endoscopic Suturing System, X-Tack® Endoscopic HeliX Tacking System (collectively "ESS") and the ORBERA® Intragastric Balloon ("IGB"). The Company has offices in the United Kingdom and Italy that oversee commercial activities outside the U.S. and a products manufacturing facility in Costa Rica. All other activities are managed and operated from facilities in Austin, Texas.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In March 2020, ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting
Net Loss Per Share	The basic and diluted net loss per common share presented in the condensed consolidated statements of operations and comprehensive loss is calculated by dividing net loss by the weighted-average number of common shares outstanding during the period, without consideration for common stock equivalents. Potentially dilutive shares, which include warrants for the purchase of common stock, convertible debt, restricted stock units, including performance-based stock units, and options outstanding under the Company's equity incentive plans, are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive.

Inventory (Tables)

Inventory (Tables)	9 Months Ended
	Sep. 30, 2021
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consists of the following as of: September 30, 2021 December 31, 2020 (unaudited) Raw materials $ 3,037 $ 2,344 Work in progress 1,141 558 Finished goods 7,139 7,404 Total inventory $ 11,317 $ 10,306

Property, Equipment and Right_2

Property, Equipment and Right-of-Use Assets (Tables)	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property, equipment and right-of-use assets consists of the following: Depreciable Lives September 30, 2021 December 31, 2020 (unaudited) Equipment 5 years $ 7,483 $ 7,452 Right-of-use assets 1-8 years 3,449 4,031 Furniture, fixtures and tooling 4-8 years 2,471 2,156 Computer hardware 3-5 years 1,305 1,244 Leasehold improvements 3-7 years 2,052 1,744 Construction in process 408 466 17,168 17,093 Less accumulated depreciation (11,582) (10,872) Property, equipment and right-of-use assets, net $ 5,586 $ 6,221
Operating Lease Maturity	As of September 30, 2021, the maturities of the Company's operating lease liabilities are as follows: 2021 $ 340 2022 791 2023 492 2024 443 2025 404 Thereafter 1,172 Total lease payments 3,642 Less imputed interest (923) Total operating lease liabilities $ 2,719

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consists of the following as of: September 30, 2021 December 31, 2020 (unaudited) Accrued employee compensation and expenses $ 5,449 $ 3,946 Accrued professional service fees 604 358 Lease liability 653 675 Accrued taxes 779 442 Accrued interest 307 616 Accrued returns and rebates 220 129 Other 1,239 1,191 Total accrued expenses $ 9,251 $ 7,357

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Schedule of Long-term Debt	Long-term debt consists of the following as of: September 30, 2021 December 31, 2020 (unaudited) Term loan facility $ 35,000 $ 35,000 PPP loan — 2,824 Deferred interest 1,759 1,217 Deferred financing costs (986) (1,213) Less current portion (1,129) (636) Long-term debt $ 34,644 $ 37,192
Schedule of Maturities of Long-term Debt	Principal payments of the Company's long-term debt are as follows: 2021 $ — 2022 4,516 2023 13,548 2024 13,548 2025 3,388 Thereafter — $ 35,000

Convertible Debt (Tables)

Convertible Debt (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Schedule of Convertible Debt	Convertible debt consists of the following as of: September 30, 2021 December 31, 2020 (unaudited) Convertible debt $ 20,445 $ 20,519 Deferred financing costs (982) (1,132) Total convertible debt $ 19,463 $ 19,387

Warrants (Tables)

Warrants (Tables)	9 Months Ended
	Sep. 30, 2021
Other Liabilities Disclosure [Abstract]
Schedule of Warrants	Warrants consist of the following as of September 30, 2021: Warrant Expiration Date Number of shares Exercise price per share December 29, 2021 40,456 $ 13.70 February 27, 2022 163,915 $ 21.29 No expiration 13,744,504 $ 0.001 Total number of warrants outstanding 13,948,875 Weighted average exercise price of warrants outstanding $ 0.29

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Stock Option Activity	A summary of the stock option activity as of September 30, 2021 is presented below. Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Options outstanding, December 31, 2020 2,921,946 $ 3.86 7.6 years $ 1,664 Options granted 1,507,872 6.36 Options exercised (643,569) 3.66 Options forfeited (226,356) 3.27 Options outstanding, vested and expected to vest, September 30, 2021 3,559,893 $ 4.99 8.2 years $ 14,853 Options exercisable 1,430,480 $ 4.63 6.9 years $ 6,705
Schedule of Stock Options, Valuation Assumptions	The fair value of stock option grants has been estimated at the date of grant using the Black-Scholes option pricing model with the following weighted average assumptions: Nine Months Ended Nine Months Ended Risk free interest rate 1.0% 0.4% Expected dividend yield —% —% Estimated volatility 81.1% 73.8% Expected life 6.1 years 5.8 years
Schedule of Other Stock Option Information	Additional information regarding options is as follows: Nine Months Ended Nine Months Ended Weighted-average grant date fair value of options granted during the period $ 4.40 $ 1.31 Aggregate intrinsic value of options exercised during the period $ 3,116 $ —
Schedule of Restricted Stock Unit Activity	A summary of the restricted stock unit activity, including performance-based stock units, under the Company's Equity Plans as of September 30, 2021 is presented below. Units Weighted Average Grant Date Fair Value Aggregate Intrinsic Value Restricted stock units outstanding, December 31, 2020 664,666 $ 2.55 $ 2,260 Restricted stock units granted 1,111,437 6.53 Restricted stock units released (431,047) 3.97 Restricted stock units forfeited (130,135) 3.08 Restricted stock units outstanding, September 30, 2021 1,214,921 $ 5.63 $ 11,007

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of Antidilutive Securities Excluded from Computation of Diluted Loss Per Share	Potentially dilutive securities that are not included in the calculation of diluted net loss per share attributable to common stockholders because to do so would be anti-dilutive are as follows (in common stock equivalent shares on a weighted-average basis): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Warrants for common stock 13,948,875 14,725,241 13,948,875 5,744,225 Convertible debt 6,299,433 6,385,483 6,293,791 6,292,599 Common stock options 3,494,676 3,009,913 3,039,021 2,459,202 Restricted stock units 1,127,964 677,605 847,081 437,640 24,870,948 24,798,242 24,128,768 14,933,666

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Schedule of Product Sales by Product Group and Geographic Market	Product sales by product group and geographic market, based on the location of the customer, whether the U.S. or outside the U.S. ("OUS") for the periods shown were as follows: Three Months Ended September 30, 2021 Three Months Ended September 30, 2020 (unaudited) U.S. OUS Total Revenues % Total Revenues U.S. OUS Total Revenues % Total Revenues ESS $ 6,722 $ 3,504 $ 10,226 62.5 % $ 4,734 $ 2,928 $ 7,662 59.7 % IGB 2,006 3,890 5,896 36.1 % 1,853 3,021 4,874 38.0 % Other 215 14 229 1.4 % 272 18 290 2.3 % Total revenues $ 8,943 $ 7,408 $ 16,351 100.0 % $ 6,859 $ 5,967 $ 12,826 100.0 % % Total revenues 54.7 % 45.3 % 53.5 % 46.5 % Nine Months Ended September 30, 2021 Nine Months Ended September 30, 2020 (unaudited) U.S. OUS Total Revenues % Total Revenues U.S. OUS Total Revenues % Total Revenues ESS $ 18,977 $ 10,512 $ 29,489 63.0 % $ 10,873 $ 7,211 $ 18,084 62.0 % IGB 5,570 11,042 16,612 35.5 % 3,511 6,688 10,199 34.9 % Other 689 28 717 1.5 % 854 51 905 3.1 % Total revenues $ 25,236 $ 21,582 $ 46,818 100.0 % $ 15,238 $ 13,950 $ 29,188 100.0 % % Total revenues 53.9 % 46.1 % 52.2 % 47.8 %
Schedule of Long-Lived Assets by Geographic Area	The following table represents property, equipment and right-of-use assets based on the physical location of the asset: September 30, 2021 December 31, 2020 (unaudited) U.S. $ 1,832 $ 2,149 Costa Rica 3,485 3,641 Other 269 431 Total property, equipment and right-of-use assets, net $ 5,586 $ 6,221

Concentrations (Details)

Concentrations (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)bank	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Concentration Risk [Line Items]
Number of banks | bank	5
Cash and cash equivalents and restricted cash | $	$ 28,474	$ 37,200	$ 38,195	$ 30,921
Customer Concentration Risk | Accounts Receivable | CustomerOne
Concentration Risk [Line Items]
Concentration risk, percentage	11.00%

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Raw materials	$ 3,037	$ 2,344
Work in progress	1,141	558
Finished goods	7,139	7,404
Total inventory	11,317	$ 10,306
Consigned inventory	$ 117

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Prepaid Expenses And Other Current Assets [Line Items]
Prepaid expenses and other current assets	$ 4,952	$ 3,771
Prepaid Expenses and Other Current Assets
Prepaid Expenses And Other Current Assets [Line Items]
Prepaid expenses and other current assets	$ 2,947	$ 2,760

Property, Equipment and Right_3

Property, Equipment and Right-of-Use Assets (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Right-of-use assets	$ 3,449,000		$ 3,449,000		$ 4,031,000
Property and equipment, gross	17,168,000		17,168,000		17,093,000
Less accumulated depreciation	(11,582,000)		(11,582,000)		(10,872,000)
Property, equipment and right-of-use assets, net	5,586,000		5,586,000		6,221,000
Depreciation	285,000	$ 435,000	1,071,000	$ 1,346,000
Impairment charges	$ 0	$ 0	$ 0	$ 0
Minimum
Property, Plant and Equipment [Line Items]
Depreciable lives, right of use assets	1 year		1 year
Maximum
Property, Plant and Equipment [Line Items]
Depreciable lives, right of use assets	8 years		8 years
Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 7,483,000		$ 7,483,000		7,452,000
Depreciable Lives			5 years
Furniture, fixtures and tooling
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,471,000		$ 2,471,000		2,156,000
Furniture, fixtures and tooling | Minimum
Property, Plant and Equipment [Line Items]
Depreciable Lives			4 years
Furniture, fixtures and tooling | Maximum
Property, Plant and Equipment [Line Items]
Depreciable Lives			8 years
Computer hardware
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,305,000		$ 1,305,000		1,244,000
Computer hardware | Minimum
Property, Plant and Equipment [Line Items]
Depreciable Lives			3 years
Computer hardware | Maximum
Property, Plant and Equipment [Line Items]
Depreciable Lives			5 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,052,000		$ 2,052,000		1,744,000
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Depreciable Lives			3 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Depreciable Lives			7 years
Construction in process
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 408,000		$ 408,000		$ 466,000

Property, Equipment and Right_4

Property, Equipment and Right-of-Use Assets (Lease Maturity) (Details) $ in Thousands	Sep. 30, 2021USD ($)
Property, Plant and Equipment [Abstract]
2021	$ 340
2022	791
2023	492
2024	443
2025	404
Thereafter	1,172
Total lease payments	3,642
Less imputed interest	(923)
Total operating lease liabilities	$ 2,719

Property, Equipment and Right_5

Property, Equipment and Right-of-Use Assets (Lease Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Operating lease, current	$ 653		$ 653		$ 675
Operating lease, current, financial statement location	Accrued expenses		Accrued expenses
Operating lease, noncurrent	$ 2,066		$ 2,066
Operating lease, noncurrent, financial statement location	Long-term liabilities		Long-term liabilities
Cash paid within operating cash flows for operating leases	$ 174	$ 286	$ 723	$ 870
Weighted average remaining lease term	5 years 1 month 6 days		5 years 1 month 6 days
Weighted average discount rate, percent	8.90%		8.90%
Lease term	1 year		1 year

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued employee compensation and expenses	$ 5,449	$ 3,946
Accrued professional service fees	604	358
Lease liability	653	675
Accrued taxes	779	442
Accrued interest	307	616
Accrued returns and rebates	220	129
Other	1,239	1,191
Total accrued expenses	$ 9,251	$ 7,357

Long-Term Debt (Schedule of Lon

Long-Term Debt (Schedule of Long-term Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Mar. 31, 2020
Debt Instrument [Line Items]
Deferred financing costs	$ (986)	$ (1,213)
Less current portion	(1,129)	(636)
Long-term debt	34,644	37,192
Deferred interest
Debt Instrument [Line Items]
Long-term debt	1,759	1,217
PPP loan
Debt Instrument [Line Items]
Long-term debt	0	2,824	$ 2,824
Term loan facility | Term loan facility
Debt Instrument [Line Items]
Long-term debt	$ 35,000	$ 35,000

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Dec. 31, 2020	Mar. 31, 2020
Debt Instrument [Line Items]
Line of credit		$ 35,000,000		$ 35,000,000
Interest expense		1,048,000	$ 1,054,000	3,147,000	$ 3,144,000
PPP loan
Debt Instrument [Line Items]
Long-term debt		0		0			$ 2,824,000	$ 2,824,000
Loan forgiveness						$ 2,852,000
Term loan facility | Term loan facility
Debt Instrument [Line Items]
Line of credit	$ 35,000,000
Maturity date extension period	6 months
Percent of outstanding amount due	7.00%
Commitment fee percentage	5.50%
Twelve month revenue amount	$ 100,000
Long-term debt		$ 35,000,000		$ 35,000,000			$ 35,000,000
Term loan facility | Term loan facility | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	7.50%

Long-Term Debt (Schedule of Mat

Long-Term Debt (Schedule of Maturity of Long-term Debt) (Details) $ in Thousands	Sep. 30, 2021USD ($)
Debt Disclosure [Abstract]
2021	$ 0
2022	4,516
2023	13,548
2024	13,548
2025	3,388
Thereafter	0
Line of credit	$ 35,000

Convertible Debt (Schedule of C

Convertible Debt (Schedule of Convertible Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Deferred financing costs	$ (986)	$ (1,213)
Long-term debt	34,644	37,192
Convertible debt
Debt Instrument [Line Items]
Convertible debt	20,445	20,519
Deferred financing costs	(982)	(1,132)
Long-term debt	$ 19,463	$ 19,387

Convertible Debt (Narrative) (D

Convertible Debt (Narrative) (Details) $ / shares in Units, $ in Thousands	1 Months Ended					3 Months Ended		9 Months Ended
	Jul. 31, 2021shares	May 31, 2021shares	Feb. 28, 2021USD ($)shares	Jan. 31, 2021shares	Aug. 31, 2019USD ($)d$ / shares	Sep. 30, 2021USD ($)shares	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)shares	Sep. 30, 2020USD ($)shares
Debt Instrument [Line Items]
Conversion of convertible debt (in shares)		12,068
Issuance of common stock for convertible debt interest (in shares)	71,609
Conversion of convertible debt | $			$ 74					$ 74	$ 0
Interest expense | $						$ 1,048	$ 1,054	$ 3,147	$ 3,144
Common Stock
Debt Instrument [Line Items]
Conversion of convertible debt (in shares)			22,644					22,644
Issuance of common stock for convertible debt interest (in shares)						71,609		244,861	164,797
Convertible debt
Debt Instrument [Line Items]
Proceeds from convertible debt | $					$ 20,000
Interest rate					6.00%
Stock price (USD per share) | $ / shares					$ 2.5
Conversion of convertible debt (in shares)				161,184
Interest expense | $						$ 356	$ 388	$ 1,070	$ 1,144
Convertible debt | Conversion Ratio Less Than 2.50
Debt Instrument [Line Items]
Consecutive trading days (in days) | d					10
Convertible debt | Conversion Ratio Of 3.25
Debt Instrument [Line Items]
Consecutive trading days (in days) | d					30
Conversion price (USD per share) | $ / shares					$ 3.25
Stock price trigger (USD per share) | $ / shares					$ 9.75
Trading days (in days) | d					20

Warrants (Details)

Warrants (Details)	Sep. 30, 2021$ / sharesshares
Class of Warrant or Right [Line Items]
Total number of warrants outstanding (in shares) | shares	13,948,875
Exercise price (USD per share) | $ / shares	$ 0.29
Warrant Expire Period One
Class of Warrant or Right [Line Items]
Total number of warrants outstanding (in shares) | shares	40,456
Exercise price (USD per share) | $ / shares	$ 13.70
Warrant Expire Period Two
Class of Warrant or Right [Line Items]
Total number of warrants outstanding (in shares) | shares	163,915
Exercise price (USD per share) | $ / shares	$ 21.29
No expiration
Class of Warrant or Right [Line Items]
Total number of warrants outstanding (in shares) | shares	13,744,504
Exercise price (USD per share) | $ / shares	$ 0.001

Warrants - Narrative (Details)

Warrants - Narrative (Details)	Sep. 30, 2021shares
Warrant
Class of Warrant or Right [Line Items]
Issued warrants to purchase shares, number of shares (in shares)	2,668,247

Stock-Based Compensation (Stock

Stock-Based Compensation (Stock Option Activity) (Details) - Stock Option - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Options
Options outstanding, beginning balance (in shares)		2,921,946
Options granted (in shares)	1,507,872
Options exercised (in shares)	(643,569)
Options forfeited (in shares)	(226,356)
Options vested and expected to vest (in shares)	3,559,893
Options exercisable (in shares)	1,430,480
Weighted Average Exercise Price
Weighted average exercise price, beginning balance (in USD per share)		$ 3.86
Options granted (in USD per share)	$ 6.36
Options exercised (in USD per share)	3.66
Options forfeited (in USD per share)	3.27
Options vested and expected to vest (in USD per share)	4.99
Options exercisable (in USD per share)	$ 4.63
Weighted Average Remaining Contractual Term
Weighted Average Remaining Contractual Term		7 years 7 months 6 days
Options vested and expected to vest	8 years 2 months 12 days
Options exercisable	6 years 10 months 24 days
Aggregate Intrinsic Value
Aggregate intrinsic value		$ 1,664
Options vested and expected to vest	$ 14,853
Options exercisable	$ 6,705

Stock-Based Compensation (Fair

Stock-Based Compensation (Fair Value of Stock Options) (Details) - Stock Option	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate	1.00%	0.40%
Expected dividend yield	0.00%	0.00%
Estimated volatility	81.10%	73.80%
Expected life	6 years 1 month 6 days	5 years 9 months 18 days

Stock-Based Compensation (Addit

Stock-Based Compensation (Additional Information) (Details) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended	9 Months Ended
	Aug. 31, 2021USD ($)trancheshares	Mar. 31, 2021USD ($)trancheshares	Sep. 30, 2021USD ($)	Sep. 30, 2021USD ($)$ / sharesshares	Sep. 30, 2020USD ($)$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee benefits and share-based compensation			$ 26	$ 222
Unrecognized compensation expense related to unvested options			6,724	$ 6,724
Remaining amortization period				3 years 1 month 6 days
Common stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value of options granted during period (in USD per share) | $ / shares				$ 4.40	$ 1.31
Aggregate intrinsic value of options exercised during the period				$ 3,116	$ 0
Options granted (in shares) | shares				1,507,872
Common stock options | Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares) | shares		848,733
Common stock options | Chief Financial Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares) | shares	150,000
Vesting period	4 years
Vesting percentage	25.00%
Restricted stock units and Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee benefits and share-based compensation			76	$ 76
Remaining amortization period				2 years
Restricted stock units and Performance shares | Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares) | shares		707,278
Number of tranches | tranche		4
Restricted stock units and Performance shares | Chief Executive Officer | Quarter one
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount vested		$ 50,000
Restricted stock units and Performance shares | Chief Executive Officer | Quarter two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount vested		65,000
Restricted stock units and Performance shares | Chief Executive Officer | Quarter three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount vested		80,000
Restricted stock units and Performance shares | Chief Executive Officer | Quarter four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount vested		$ 95,000
Restricted stock units and Performance shares | Chief Financial Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares) | shares	120,000
Number of tranches | tranche	3
Restricted stock units and Performance shares | Chief Financial Officer | Quarter one
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount vested	$ 70,000
Restricted stock units and Performance shares | Chief Financial Officer | Quarter two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount vested	90,000
Restricted stock units and Performance shares | Chief Financial Officer | Quarter three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount vested	$ 110,000
Restricted stock units (RSUs) and time-based shares | Chief Financial Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares) | shares	80,000
Number of tranches | tranche	4
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to unvested restricted stock units			2,278	$ 2,278
Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to unvested restricted stock units			$ 3,008	$ 3,008

Stock-Based Compensation (Restr

Stock-Based Compensation (Restricted Stock Units Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Restricted stock units and Performance shares
Units
Unvested Units (shares)	664,666
Restricted stock units and performance stock units granted (shares)	1,111,437
Unvested Units (shares)	1,214,921
Weighted Average Grant Date Fair Value
Unvested Units (USD per share)	$ 2.55
Restricted stock units and performance stock units granted (USD per share)	6.53
Unvested Units (USD per share)	$ 5.63
Aggregate Intrinsic Value
Aggregate Intrinsic Value	$ 11,007	$ 2,260
Restricted stock units
Units
Restricted stock units vested (shares)	(431,047)
Restricted stock units forfeited (shares)	(130,135)
Weighted Average Grant Date Fair Value
Restricted stock units vested (USD per share)	$ 3.97
Restricted stock units forfeited (USD per share)	$ 3.08

Income Taxes (Details)

Income Taxes (Details)	Sep. 30, 2021USD ($)
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 0
Accrued interest	0
Tax penalties	$ 0

Net Loss Per Share (Details)

Net Loss Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted loss per share (in shares)	24,870,948	24,798,242	24,128,768	14,933,666
Warrants for common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted loss per share (in shares)	13,948,875	14,725,241	13,948,875	5,744,225
Convertible debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted loss per share (in shares)	6,299,433	6,385,483	6,293,791	6,292,599
Common stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted loss per share (in shares)	3,494,676	3,009,913	3,039,021	2,459,202
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted loss per share (in shares)	1,127,964	677,605	847,081	437,640

Fair Value Measurements (Detail

Fair Value Measurements (Details) $ in Thousands	Sep. 30, 2021USD ($)
Fair Value Disclosures [Abstract]
Fair value of long-term debt	$ 38,800
Convertible debt, fair value	$ 20,400

Segment and Geographic Inform_3

Segment and Geographic Information (Segment Information) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)segment	Sep. 30, 2020USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment			1
Revenue, Major Customer [Line Items]
Revenues	$ 16,351	$ 12,826	$ 46,818	$ 29,188
Segment Revenue | Product Risk
Revenue, Major Customer [Line Items]
Percentage of revenue or sales	100.00%	100.00%	100.00%	100.00%
U.S.
Revenue, Major Customer [Line Items]
Revenues	$ 8,943	$ 6,859	$ 25,236	$ 15,238
U.S. | Segment Revenue | Product Risk
Revenue, Major Customer [Line Items]
Percentage of revenue or sales	54.70%	53.50%	53.90%	52.20%
OUS
Revenue, Major Customer [Line Items]
Revenues	$ 7,408	$ 5,967	$ 21,582	$ 13,950
OUS | Segment Revenue | Product Risk
Revenue, Major Customer [Line Items]
Percentage of revenue or sales	45.30%	46.50%	46.10%	47.80%
OUS | Distributor Sales | Product Risk
Revenue, Major Customer [Line Items]
Percentage of revenue or sales	46.40%	30.40%	42.40%	31.40%
Non-US, Next Largest Single Country | Distributor Sales | Product Risk | Minimum
Revenue, Major Customer [Line Items]
Percentage of revenue or sales	6.00%	8.00%	6.00%	8.00%
Non-US, Next Largest Single Country | Distributor Sales | Product Risk | Maximum
Revenue, Major Customer [Line Items]
Percentage of revenue or sales	7.00%	9.00%	7.00%	9.00%
ESS
Revenue, Major Customer [Line Items]
Revenues	$ 10,226	$ 7,662	$ 29,489	$ 18,084
ESS | Segment Revenue | Product Risk
Revenue, Major Customer [Line Items]
Percentage of revenue or sales	62.50%	59.70%	63.00%	62.00%
ESS | U.S.
Revenue, Major Customer [Line Items]
Revenues	$ 6,722	$ 4,734	$ 18,977	$ 10,873
ESS | OUS
Revenue, Major Customer [Line Items]
Revenues	3,504	2,928	10,512	7,211
IGB
Revenue, Major Customer [Line Items]
Revenues	$ 5,896	$ 4,874	$ 16,612	$ 10,199
IGB | Segment Revenue | Product Risk
Revenue, Major Customer [Line Items]
Percentage of revenue or sales	36.10%	38.00%	35.50%	34.90%
IGB | U.S.
Revenue, Major Customer [Line Items]
Revenues	$ 2,006	$ 1,853	$ 5,570	$ 3,511
IGB | OUS
Revenue, Major Customer [Line Items]
Revenues	3,890	3,021	11,042	6,688
Other
Revenue, Major Customer [Line Items]
Revenues	$ 229	$ 290	$ 717	$ 905
Other | Segment Revenue | Product Risk
Revenue, Major Customer [Line Items]
Percentage of revenue or sales	1.40%	2.30%	1.50%	3.10%
Other | U.S.
Revenue, Major Customer [Line Items]
Revenues	$ 215	$ 272	$ 689	$ 854
Other | OUS
Revenue, Major Customer [Line Items]
Revenues	$ 14	$ 18	$ 28	$ 51

Segment and Geographic Inform_4

Segment and Geographic Information (Long-Lived Assets by Geographic Area) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property, equipment and right-of-use assets, net	$ 5,586	$ 6,221
U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property, equipment and right-of-use assets, net	1,832	2,149
Costa Rica
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property, equipment and right-of-use assets, net	3,485	3,641
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property, equipment and right-of-use assets, net	$ 269	$ 431

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	9 Months Ended
	Oct. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Subsequent Event [Line Items]
Common stock, shares issued (shares)		29,829,697		25,819,329
Common stock, par value (USD per share)		$ 0.001		$ 0.001
Proceeds from issuance of common stock		$ 0	$ 23,262
Subsequent Event
Subsequent Event [Line Items]
Common stock, shares issued (shares)	9,660,000
Common stock, par value (USD per share)	$ 0.001
Sale of stock, price per share (USD per share)	$ 7.75
Proceeds from issuance of common stock	$ 74,900